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ENGINEERING (1320 journals)                  1 2 3 4 5 6 7 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 8)
3D Research     Hybrid Journal   (Followers: 21)
AAPG Bulletin     Hybrid Journal   (Followers: 8)
AASRI Procedia     Open Access   (Followers: 15)
Abstract and Applied Analysis     Open Access   (Followers: 3)
Aceh International Journal of Science and Technology     Open Access   (Followers: 7)
ACS Nano     Hybrid Journal   (Followers: 310)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 3)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Active and Passive Electronic Components     Open Access   (Followers: 7)
Adaptive Behavior     Hybrid Journal   (Followers: 10)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 9)
Advanced Journal of Graduate Research     Open Access  
Advanced Nonlinear Studies     Hybrid Journal  
Advanced Science     Open Access   (Followers: 6)
Advanced Science Focus     Free   (Followers: 5)
Advanced Science Letters     Full-text available via subscription   (Followers: 11)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 7)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 5)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Complex Systems     Hybrid Journal   (Followers: 9)
Advances in Engineering Software     Hybrid Journal   (Followers: 28)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 14)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 23)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 23)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 29)
Advances in Nonlinear Analysis     Hybrid Journal  
Advances in Operations Research     Open Access   (Followers: 12)
Advances in OptoElectronics     Open Access   (Followers: 6)
Advances in Physics Theories and Applications     Open Access   (Followers: 16)
Advances in Polymer Science     Hybrid Journal   (Followers: 45)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Remote Sensing     Open Access   (Followers: 50)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aerobiologia     Hybrid Journal   (Followers: 3)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 6)
AIChE Journal     Hybrid Journal   (Followers: 35)
Ain Shams Engineering Journal     Open Access   (Followers: 5)
Akademik Platform Mühendislik ve Fen Bilimleri Dergisi     Open Access   (Followers: 1)
Al-Nahrain Journal for Engineering Sciences     Open Access  
Alexandria Engineering Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
American Journal of Applied Sciences     Open Access   (Followers: 27)
American Journal of Engineering and Applied Sciences     Open Access   (Followers: 10)
American Journal of Engineering Education     Open Access   (Followers: 12)
American Journal of Environmental Engineering     Open Access   (Followers: 16)
American Journal of Industrial and Business Management     Open Access   (Followers: 25)
Anadolu University Journal of Science and Technology A : Applied Sciences and Engineering     Open Access  
Annals of Combinatorics     Hybrid Journal   (Followers: 4)
Annals of Pure and Applied Logic     Open Access   (Followers: 3)
Annals of Regional Science     Hybrid Journal   (Followers: 8)
Annals of Science     Hybrid Journal   (Followers: 7)
Antarctic Science     Hybrid Journal   (Followers: 1)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 3)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 6)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 20)
Applied Clay Science     Hybrid Journal   (Followers: 6)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 14)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 4)
Applied Nanoscience     Open Access   (Followers: 8)
Applied Network Science     Open Access   (Followers: 3)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 7)
Applied Sciences     Open Access   (Followers: 3)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 6)
Arab Journal of Basic and Applied Sciences     Open Access  
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 5)
Archives of Foundry Engineering     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 9)
Arid Zone Journal of Engineering, Technology and Environment     Open Access   (Followers: 2)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 3)
Asia-Pacific Journal of Science and Technology     Open Access  
Asian Engineering Review     Open Access  
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 2)
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 9)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 8)
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
AURUM : Mühendislik Sistemleri ve Mimarlık Dergisi = Aurum Journal of Engineering Systems and Architecture     Open Access  
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Full-text available via subscription   (Followers: 2)
Automotive Experiences     Open Access  
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Avances en Ciencias e Ingeniería     Open Access  
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 1)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 5)
Batteries     Open Access   (Followers: 6)
Bautechnik     Hybrid Journal   (Followers: 1)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 28)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 4)
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 1)
BER : Motor Trade Survey     Full-text available via subscription  
BER : Retail Sector Survey     Full-text available via subscription   (Followers: 1)
BER : Retail Survey : Full Survey     Full-text available via subscription   (Followers: 1)
BER : Survey of Business Conditions in Manufacturing : An Executive Summary     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Retail : An Executive Summary     Full-text available via subscription   (Followers: 3)
Beyond : Undergraduate Research Journal     Open Access  
Bhakti Persada : Jurnal Aplikasi IPTEKS     Open Access  
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access   (Followers: 1)
Bilge International Journal of Science and Technology Research     Open Access  
Biofuels Engineering     Open Access   (Followers: 1)
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 11)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering     Hybrid Journal   (Followers: 2)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 5)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 20)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 35)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 8)
Biomedical Science and Engineering     Open Access   (Followers: 4)
Biomicrofluidics     Open Access   (Followers: 5)
BioNanoMaterials     Open Access   (Followers: 2)
Biotechnology Progress     Hybrid Journal   (Followers: 40)
Bitlis Eren University Journal of Science and Technology     Open Access  
Black Sea Journal of Engineering and Science     Open Access  
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription   (Followers: 1)
Boundary Value Problems     Open Access   (Followers: 1)
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 12)
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 13)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 14)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers Droit, Sciences & Technologies     Open Access  
Calphad     Hybrid Journal   (Followers: 2)
Canadian Geotechnical Journal     Hybrid Journal   (Followers: 31)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 45)
Carbon Resources Conversion     Open Access   (Followers: 1)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 6)
Case Studies in Thermal Engineering     Open Access   (Followers: 6)
Catalysis Communications     Hybrid Journal   (Followers: 6)
Catalysis Letters     Hybrid Journal   (Followers: 2)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 7)
Catalysis Science and Technology     Free   (Followers: 8)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 7)
CEAS Space Journal     Hybrid Journal   (Followers: 2)
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 3)
Central European Journal of Engineering     Hybrid Journal  
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 3)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Engineering     Open Access   (Followers: 2)
Chinese Science Bulletin     Open Access   (Followers: 1)
Ciencia e Ingenieria Neogranadina     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencia y Tecnología     Open Access  
Ciencias Holguin     Open Access   (Followers: 3)
CienciaUAT     Open Access   (Followers: 1)
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Full-text available via subscription   (Followers: 11)
CIRP Journal of Manufacturing Science and Technology     Full-text available via subscription   (Followers: 13)
City, Culture and Society     Hybrid Journal   (Followers: 23)
Clean Air Journal     Full-text available via subscription   (Followers: 1)
Clinical Science     Hybrid Journal   (Followers: 8)
Coal Science and Technology     Full-text available via subscription   (Followers: 3)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 6)
Coatings     Open Access   (Followers: 4)
Cogent Engineering     Open Access   (Followers: 3)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Color Research & Application     Hybrid Journal   (Followers: 3)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 14)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 15)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications Faculty of Sciences University of Ankara Series A2-A3 Physical Sciences and Engineering     Open Access  
Communications in Information Science and Management Engineering     Open Access   (Followers: 4)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Components, Packaging and Manufacturing Technology, IEEE Transactions on     Hybrid Journal   (Followers: 29)
Composite Interfaces     Hybrid Journal   (Followers: 7)
Composite Structures     Hybrid Journal   (Followers: 291)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 228)
Composites Part B : Engineering     Hybrid Journal   (Followers: 270)
Composites Science and Technology     Hybrid Journal   (Followers: 202)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access   (Followers: 1)
Computational Geosciences     Hybrid Journal   (Followers: 17)
Computational Optimization and Applications     Hybrid Journal   (Followers: 9)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 8)

        1 2 3 4 5 6 7 | Last

Journal Cover
Number of Followers: 6  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2313-0105
Published by MDPI Homepage  [205 journals]
  • Batteries, Vol. 5, Pages 2: Investigation of Reactant Conversion in the
           Vanadium Redox Flow Battery Using Spatially Resolved State of Charge

    • Authors: Purna C. Ghimire, Arjun Bhattarai, Rüdiger Schweiss, Günther G. Scherer, Nyunt Wai, Tuti M. Lim, Qingyu Yan
      First page: 2
      Abstract: Segmented cells enable real time visualization of the flow distribution in vanadium redox flow batteries by local current or voltage mapping. The lateral flow of current within thick porous electrodes, however, impairs the local resolution of the detected signals. In this study, the open circuit voltage immediately after the cessation of charge/discharge is used for the mapping of reactant conversion. This quantity is not hampered by lateral flow of current and can be conveniently transformed to the corresponding state of charge. The difference between theoretically calculated and experimentally determined conversion (change in the state of charge) across the electrode is used to determine local variations in conversion efficiency. The method is validated by systematic experiments using electrodes with different modifications, varying current densities and flow configurations. The procedure and the interpretation are simple and scalable to any size of flow cell.
      Citation: Batteries
      PubDate: 2019-01-01
      DOI: 10.3390/batteries5010002
      Issue No: Vol. 5, No. 1 (2019)
  • Batteries, Vol. 5, Pages 3: Prototype System of Rocking-Chair Zn-Ion
           Battery Adopting Zinc Chevrel Phase Anode and Rhombohedral Zinc
           Hexacyanoferrate Cathode

    • Authors: Munseok S. Chae, Seung-Tae Hong
      First page: 3
      Abstract: Zinc-ion batteries (ZIBs) have received attention as one type of multivalent-ion batteries due to their potential applications in large-scale energy storage systems. Here we report a prototype of rocking-chair ZIB system employing Zn2Mo6S8 (zinc Chevrel phase) as an anode operating at 0.35 V, and K0.02(H2O)0.22Zn2.94[Fe(CN)6]2 (rhombohedral zinc Prussian-blue analogue) as a cathode operating at 1.75 V (vs. Zn/Zn2+) in ZnSO4 aqueous electrolyte. This type of cell has a benefit due to its intrinsic zinc-dendrite-free nature. The cell is designed to be positive-limited with a capacity of 62.3 mAh g−1. The full-cell shows a reversible cycle with an average discharge cell voltage of ~1.40 V, demonstrating a successful rocking-chair zinc-ion battery system.
      Citation: Batteries
      PubDate: 2019-01-02
      DOI: 10.3390/batteries5010003
      Issue No: Vol. 5, No. 1 (2019)
  • Batteries, Vol. 5, Pages 4: Real-Time State-of-Charge Estimation via
           Particle Swarm Optimization on a Lithium-Ion Electrochemical Cell Model

    • Authors: Arun Chandra Shekar, Sohel Anwar
      First page: 4
      Abstract: With the ever-increasing usage of lithium-ion batteries, especially in transportation applications, accurate estimation of battery state of charge (SOC) is of paramount importance. A majority of the current SOC estimation methods rely on data collected and calibrated offline, which could lead to inaccuracies in SOC estimation under different operating conditions or when the battery ages. This paper presents a novel real-time SOC estimation of a lithium-ion battery by applying the particle swarm optimization (PSO) method to a detailed electrochemical model of a single cell. This work also optimizes both the single-cell model and PSO algorithm so that the developed algorithm can run on an embedded hardware with reasonable utilization of central processing unit (CPU) and memory resources while estimating the SOC with reasonable accuracy. A modular single-cell electrochemical model, as well as the proposed constrained PSO-based SOC estimation algorithm, was developed in Simulink©, and its performance was theoretically verified in simulation. Experimental data were collected for healthy and aged Li-ion battery cells in order to validate the proposed algorithm. Both simulation and experimental results demonstrate that the developed algorithm is able to accurately estimate the battery SOC for 1C charge and 1C discharge operations for both healthy and aged cells.
      Citation: Batteries
      PubDate: 2019-01-04
      DOI: 10.3390/batteries5010004
      Issue No: Vol. 5, No. 1 (2019)
  • Batteries, Vol. 5, Pages 5: Monitoring the State of Charge of the Positive
           Electrolyte in a Vanadium Redox-Flow Battery with a Novel Amperometric

    • Authors: Isabelle Kroner, Maik Becker, Thomas Turek
      First page: 5
      Abstract: Vanadium redox-flow batteries are a promising energy storage technology due to their safety, long-term stability, and independent adjustability of power and capacity. However, the vanadium crossover through the membrane causes a self-discharge, which results in a capacity shift towards one half cell. This leads to a gradual decrease in its efficiency over time. Capacity balancing methods for compensation of this effect require a reliable online state of charge (SoC) monitoring. Most common methods cannot provide exact values of the individual concentration of each species in both electrolytes. In particular, the state of the positive electrolyte cannot yet be precisely determined. In this work, an amperometric SoC monitoring is proposed as a new approach. First, the suitability of the principle is investigated with a rotating disc electrode (RDE). Then, a sensor based on a gas diffusion layer (GDL) is developed and tested in the positive electrolyte. The dependencies between oxidative current and V(IV)-concentration are examined as well as those between reduction current and V(V)-concentration. Using both relationships, a reliable measurement of all relevant concentrations is possible.
      Citation: Batteries
      PubDate: 2019-01-05
      DOI: 10.3390/batteries5010005
      Issue No: Vol. 5, No. 1 (2019)
  • Batteries, Vol. 5, Pages 6: Investigations on a Mesoporous Glass Membrane
           as Ion Separator for a Redox Flow Battery

    • Authors: Ioannis Michos, Zishu Cao, Zhi Xu, Wenheng Jing, Junhang Dong
      First page: 6
      Abstract: This article reports extensive studies of a Vycor® porous glass (VPG) membrane as an ion separator for an all-vanadium redox flow battery (VRFB). The VPG membrane had an average pore size of 4 nm and porosity of ~28%. The VPG ion separator exhibited higher proton diffusivity but lower conductivity than the Nafion® 117 membrane because the former is intrinsically nonionic. The VRFB equipped with the VPG ion separator (VPG-VRFB) exhibited much better stability during long-term cyclic operation than the VRFB equipped with the Nafion-117 membrane (Nafion-VRFB) because the ionic Nafion membrane could be contaminated by vanadium ions exchanged into the water channels. This increases its area specific resistance, while the VPG does not have ion exchange capacity and hence has less vanadium ion contamination. The VPG-VRFB was found to outperform the Nafion-VRFB in energy efficiency (EE) during long-term cyclic operation although the former underperformed the latter in the initial period of continued operation. The VPG ion separator also showed markedly better thermal stability and temperature tolerance than the Nafion membrane as indicated by the significantly smaller losses of EE and discharge capacity for the VPG-VRFB than for the Nafion-VRFB after operating at 45 °C. The outstanding temperature tolerance of the VPG ion separator is due primarily to its rigid and non-swelling pore structure and nonionic nature, which are highly resistant to thermal distortion and vanadium ion contamination. The excellent temperature tolerance of the VPG may be useful for applications where temperature control is difficult.
      Citation: Batteries
      PubDate: 2019-01-05
      DOI: 10.3390/batteries5010006
      Issue No: Vol. 5, No. 1 (2019)
  • Batteries, Vol. 5, Pages 7: Acknowledgement to Reviewers of Batteries in

    • Authors: Batteries Editorial Office
      First page: 7
      Abstract: Rigorous peer-review is the corner-stone of high-quality academic publishing [...]
      Citation: Batteries
      PubDate: 2019-01-11
      DOI: 10.3390/batteries5010007
      Issue No: Vol. 5, No. 1 (2019)
  • Batteries, Vol. 5, Pages 8: Characterizing Large-Scale, Electric-Vehicle
           Lithium Ion Transportation Batteries for Secondary Uses in Grid

    • Authors: Christopher Valant, Gabrielle Gaustad, Nenad Nenadic
      First page: 8
      Abstract: Lithium ion battery modules have significant capacity left after their useful life in transportation applications. This empirical study successfully tested the used modules in secondary grid applications in laboratory conditions. The selection of the secondary application was based on the construction features of the modules and the growing need for storage in grid operations. Description of the laboratory setup is provided in the context of a critical practical constraint where the battery management system and the usage and health history are not available to the secondary battery integrator. Charge and discharge profiles were developed based upon applications for peak shaving and firming renewables. Techno-economic analysis was focused on peak shaving at the utility level, considering a growing need for an affordable and environmentally friendly replacement to the traditional solutions based on environmentally costly peaker plants. The analysis showed strong evidence that near-term and future storage markets will be characterized by a large mismatch between the demand and supply of reused batteries from automotive primary applications for peak-shaving purposes in the generation side. The paper includes a discussion on successful adoption of cascaded use of batteries and their potential to reduce both economic and environmental cost of peak shaving.
      Citation: Batteries
      PubDate: 2019-01-12
      DOI: 10.3390/batteries5010008
      Issue No: Vol. 5, No. 1 (2019)
  • Batteries, Vol. 5, Pages 9: Real-Time Performance Optimization and
           Diagnostics during Long-Term Operation of a Solid Anolyte Microbial Fuel
           Cell Biobattery

    • Authors: Ademola Adekunle, Vijaya Raghavan, Boris Tartakovsky
      First page: 9
      Abstract: This study describes a novel approach for real-time energy harvesting and performance diagnostics of a solid anolyte microbial fuel cell (SA-MFC) representing a prototype smart biobattery. The biobattery power output was maximized in real time by combining intermittent power generation with a Perturbation-and-Observation algorithm for maximum power point tracking. The proposed approach was validated by operating the biobattery under a broad range of environmental conditions affecting power production, such as temperature (4–25 °C), NaCl concentration (up to 2 g L−1), and carbon source concentration. Real-time biobattery performance diagnostics was achieved by estimating key internal parameters (resistance, capacitance, open circuit voltage) using an equivalent electrical circuit model. The real time optimization approach ensured maximum power production during 388 days of biobattery operation under varying environmental conditions, thus confirming the feasibility of biobattery application for powering small electronic devices in field applications.
      Citation: Batteries
      PubDate: 2019-01-15
      DOI: 10.3390/batteries5010009
      Issue No: Vol. 5, No. 1 (2019)
  • Batteries, Vol. 5, Pages 10: Exploring the Economic Potential of
           Sodium-Ion Batteries

    • Authors: Jens F. Peters, Alexandra Peña Cruz, Marcel Weil
      First page: 10
      Abstract: Sodium-ion batteries (SIBs) are a recent development being promoted repeatedly as an economically promising alternative to lithium-ion batteries (LIBs). However, only one detailed study about material costs has yet been published for this battery type. This paper presents the first detailed economic assessment of 18,650-type SIB cells with a layered oxide cathode and a hard carbon anode, based on existing datasheets for pre-commercial battery cells. The results are compared with those of competing LIB cells, that is, with lithium-nickel-manganese-cobalt-oxide cathodes (NMC) and with lithium-iron-phosphate cathodes (LFP). A sensitivity analysis further evaluates the influence of varying raw material prices on the results. For the SIB, a cell price of 223 €/kWh is obtained, compared to 229 €/kWh for the LFP and 168 €/kWh for the NMC batteries. The main contributor to the price of the SIB cells are the material costs, above all the cathode and anode active materials. For this reason, the amount of cathode active material (e.g., coating thickness) in addition to potential fluctuations in the raw material prices have a considerable effect on the price per kWh of storage capacity. Regarding the anode, the precursor material costs have a significant influence on the hard carbon cost, and thus on the final price of the SIB cell. Organic wastes and fossil coke precursor materials have the potential of yielding hard carbon at very competitive costs. In addition, cost reductions in comparison with LIBs are achieved for the current collectors, since SIBs also allow the use of aluminum instead of copper on the anode side. For the electrolyte, the substitution of lithium with sodium leads to only a marginal cost decrease from 16.1 to 15.8 €/L, hardly noticeable in the final cell price. On the other hand, the achievable energy density is fundamental. While it seems difficult to achieve the same price per kWh as high energy density NMC LIBs, the SIB could be a promising substitute for LFP cells in stationary applications, if it also becomes competitive with LFP cells in terms of safety and cycle life.
      Citation: Batteries
      PubDate: 2019-01-16
      DOI: 10.3390/batteries5010010
      Issue No: Vol. 5, No. 1 (2019)
  • Batteries, Vol. 5, Pages 11: Silicon/Mesoporous Carbon (Si/MC) Derived
           from Phenolic Resin for High Energy Anode Materials for Li-ion Batteries:
           Role of HF Etching and Vinylene Carbonate (VC) Additive

    • Authors: Arlavinda Rezqita, Hristina Vasilchina, Raad Hamid, Markus Sauer, Annette Foelske, Corina Täubert, Hermann Kronberger
      First page: 11
      Abstract: Silicon/mesoporous carbon (Si/MC) composites with optimum Si content, in which the volumetric energy density would be maximized, while volume changes would be minimized, have been developed. The composites were prepared by dispersing Si nanoparticles in a phenolic resin as a carbon source, subsequent carbonization, and etching with hydrofluoric acid (HF). Special attention was paid to understanding the role of HF etching as post-treatment to provide additional void spaces in the composites. The etching process was shown to reduce the SiO2 native layer on the Si nanoparticles, resulting in increased porosity in comparison to the non-etched composite material. For cell optimization, vinylene carbonate (VC) was employed as an electrolyte additive to build a stable solid electrolyte interphase (SEI) layer on the electrode. The composition of the SEI layer on Si/MC electrodes, cycled with and without VC-containing electrolytes for several cycles, was then comprehensively investigated by using ex-situ XPS. The SEI layers on the electrodes working with VC-containing electrolyte were more stable than those in configurations without VC; this explains why our sample with VC exhibits lower irreversible capacity losses after several cycles. The optimized Si/MC composites exhibit a reversible capacity of ~800 mAhg−1 with an average coulombic efficiency of ~99 % over 400 cycles at C/10.
      Citation: Batteries
      PubDate: 2019-01-16
      DOI: 10.3390/batteries5010011
      Issue No: Vol. 5, No. 1 (2019)
  • Batteries, Vol. 5, Pages 1: Electrochemical Performance and in Operando
           Charge Efficiency Measurements of Cu/Sn-Doped Nano Iron Electrodes

    • Authors: Alagar Raj Paulraj, Yohannes Kiros, Mylad Chamoun, Henrik Svengren, Dag Noréus, Mats Göthelid, Björn Skårman, Hilmar Vidarsson, Malin B. Johansson
      First page: 1
      Abstract: Fe-air or Ni-Fe cells can offer low-cost and large-scale sustainable energy storage. At present, they are limited by low coulombic efficiency, low active material use, and poor rate capability. To overcome these challenges, two types of nanostructured doped iron materials were investigated: (1) copper and tin doped iron (CuSn); and (2) tin doped iron (Sn). Single-wall carbon nanotube (SWCNT) was added to the electrode and LiOH to the electrolyte. In the 2 wt. % Cu + 2 wt. % Sn sample, the addition of SWCNT increased the discharge capacity from 430 to 475 mAh g−1, and charge efficiency increased from 83% to 93.5%. With the addition of both SWCNT and LiOH, the charge efficiency and discharge capacity improved to 91% and 603 mAh g−1, respectively. Meanwhile, the 4 wt. % Sn substituted sample performance is not on par with the 2 wt. % Cu + 2 wt. % Sn sample. The dopant elements (Cu and Sn) and additives (SWCNT and LiOH) have a major impact on the electrode performance. To understand the relation between hydrogen evolution and charge current density, we have used in operando charging measurements combined with mass spectrometry to quantify the evolved hydrogen. The electrodes that were subjected to prolonged overcharge upon hydrogen evolution failed rapidly. This insight could help in the development of better charging schemes for the iron electrodes.
      Citation: Batteries
      PubDate: 2018-12-21
      DOI: 10.3390/batteries5010001
      Issue No: Vol. 5, No. 1 (2018)
  • Batteries, Vol. 4, Pages 48: Novel Approaches for Solving the Capacity
           Fade Problem during Operation of a Vanadium Redox Flow Battery

    • Authors: Arjun Bhattarai, Purna C. Ghimire, Adam Whitehead, Rüdiger Schweiss, Günther G. Scherer, Nyunt Wai, Huey Hoon Hng
      First page: 48
      Abstract: The vanadium redox flow battery (VRFB) is one of the most mature and commercially available electrochemical technologies for large-scale energy storage applications. The VRFB has unique advantages, such as separation of power and energy capacity, long lifetime (>20 years), stable performance under deep discharge cycling, few safety issues and easy recyclability. Despite these benefits, practical VRFB operation suffers from electrolyte imbalance, which is primarily due to the transfer of water and vanadium ions through the ion-exchange membranes. This can cause a cumulative capacity loss if the electrolytes are not rebalanced. In commercial systems, periodic complete or partial remixing of electrolyte is performed using a by-pass line. However, frequent mixing impacts the usable energy and requires extra hardware. To address this problem, research has focused on developing new membranes with higher selectivity and minimal crossover. In contrast, this study presents two alternative concepts to minimize capacity fade that would be of great practical benefit and are easy to implement: (1) introducing a hydraulic shunt between the electrolyte tanks and (2) having stacks containing both anion and cation exchange membranes. It will be shown that the hydraulic shunt is effective in passively resolving the continuous capacity loss without detrimentally influencing the energy efficiency. Similarly, the combination of anion and cation exchange membranes reduced the net electrolyte flux, reducing capacity loss. Both approaches work efficiently and passively to reduce capacity fade during operation of a flow battery system.
      Citation: Batteries
      PubDate: 2018-10-01
      DOI: 10.3390/batteries4040048
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 49: Accelerated Internal Resistance Measurements
           of Lithium-Ion Cells to Support Future End-of-Life Strategies for Electric

    • Authors: Thomas R. B. Grandjean, Jakobus Groenewald, Andrew McGordon, Widanalage D. Widanage, James Marco
      First page: 49
      Abstract: Industrial and academic communities have embarked on investigating the sustainability of vehicles that contain embedded electrochemical energy storage systems. Circular economy strategies for electric vehicle (EV) or hybrid electric vehicle (HEV) battery systems are underpinned by implicit assumptions about the state of health (SOH) of the battery. The internal resistance of battery systems is the essential property for determining available power, energy efficiency, and heat generation. Consequently, precise measurement is crucial to estimate the SOH; however, the international standards and best practice guides that exist to define the measurements include long preconditioning and rest times that make the test duration prohibitive. The aim of this research is to critically evaluate whether test duration times for internal resistance measurements can be reduced to values that may facilitate further end-of-life (EOL) options. Results reveal a newly developed technique using pulse-multisines is two to four times faster to perform when compared to the standard protocol whilst maintaining accuracy for battery electric vehicle (BEV) and HEV cells, respectively. This novel method allows different stakeholders to rank the relative importance of test accuracy verses experimental test time when categorising used Li-ion cells for different EOL applications.
      Citation: Batteries
      PubDate: 2018-10-04
      DOI: 10.3390/batteries4040049
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 50: A Review: Carbon Additives in LiMnPO4- and
           LiCoO2-Based Cathode Composites for Lithium Ion Batteries

    • Authors: Nam Kwon, Divine Mouck-Makanda, Katharina Fromm
      First page: 50
      Abstract: Carbon plays a critical role in improving the electronic conductivity of cathodes in lithium ion batteries. Particularly, the characteristics of carbon and its composite with electrode material strongly affect battery properties, governed by electron as well as Li+ ion transport. We have reviewed here various types of carbon materials and organic carbon sources in the production of conductive composites of nano-LiMnPO4 and LiCoO2. Various processes of making these composites with carbon or organic carbon sources and their characterization have been reviewed. Finally, the type and amount of carbon and the preparation methods of composites are summarized along with their battery performances and cathode materials. Among the different processes of making a composite, ball milling provided the benefit of dense and homogeneous nanostructured composites, leading to higher tap-density and thus increasing the volumetric energy densities of cathodes.
      Citation: Batteries
      PubDate: 2018-10-15
      DOI: 10.3390/batteries4040050
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 51: Leaching of Metals from Waste Silver
           Oxide-Zinc Button Cell Batteries by Aspergillus niger

    • Authors: Umesh Jadhav, Chun-Hui Su, Mital Chakankar, Hong Hocheng
      First page: 51
      Abstract: Leaching of metals from waste button cell batteries was explored in this study. Aspergillus niger spent medium was used for metal leaching to avoid toxicity of metals toward microbial cells. Process parameters including time, temperature, shaking speed, and volume of the spent medium were optimized. We obtained 100% leaching of zinc and silver in six hours at 60 °C and 100 rpm using 15 mL spent medium. The use of spent medium supported the indirect leaching process. The organic acid produced by fungi acts as a lixiviant, aiding the metal leaching in this process.
      Citation: Batteries
      PubDate: 2018-10-17
      DOI: 10.3390/batteries4040051
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 52: Passive Tracking of the Electrochemical
           Impedance of a Hybrid Electric Vehicle Battery and State of Charge
           Estimation through an Extended and Unscented Kalman Filter

    • Authors: Nicolas Sockeel, John Ball, Masood Shahverdi, Michael Mazzola
      First page: 52
      Abstract: Estimation of a lithium battery electrical impedance can provide relevant information regarding its characteristics. Currently, electrochemical impedance spectroscopy (EIS) constitutes the most recognized and accepted method. Although highly precise and robust, EIS is usually performed during laboratory testing and is not suitable for any on-board application, such as in battery electric vehicles (BEVs) because it is an instrumentally and computationally heavy method. To address this issue and on-line system applications, this manuscript describes, as a main contribution, a passive method for battery impedance estimation in the time domain that involves the voltage and current profile induced by the battery through its ordinary operation without injecting a small excitation signal. This method has been tested on the same battery with different passive voltage and current profile and has been validated by achieving similar results. Compared to the original idea presented in the published conference paper, this manuscript explains, in detail, the previously developed method of transforming the battery impedance from the frequency domain to time domain. Moreover, this impedance measurement is used to estimate more robustly the battery state of charge (SoC) through Kalman filters. In the original published conference paper, only an extended Kalman filter (EKF) was applied. However, in this manuscript, an EKF and an unscented Kalman filter (UKF) are used and their performances are compared.
      Citation: Batteries
      PubDate: 2018-10-19
      DOI: 10.3390/batteries4040052
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 53: Variable Porous Electrode Compression for
           Redox Flow Battery Systems

    • Authors: Nicholas Gurieff, Victoria Timchenko, Chris Menictas
      First page: 53
      Abstract: Vanadium redox flow batteries (VRFBs) offer great promise as a safe, cost effective means of storing electrical energy on a large scale and will certainly have a part to play in the global transition to renewable energy. To unlock the full potential of VRFB systems, however, it is necessary to improve their power density. Unconventional stack design shows encouraging possibilities as a means to that end. Presented here is the novel concept of variable porous electrode compression, which simulations have shown to deliver a one third increase in minimum limiting current density together with a lower pressure drop when compared to standard uniform compression cell designs.
      Citation: Batteries
      PubDate: 2018-10-22
      DOI: 10.3390/batteries4040053
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 54: Characterisation of a 200 kW/400 kWh Vanadium
           Redox Flow Battery

    • Authors: Declan Bryans, Véronique Amstutz, Hubert H. Girault, Léonard E. A. Berlouis
      First page: 54
      Abstract: The incessant growth in energy demand has resulted in the deployment of renewable energy generators to reduce the impact of fossil fuel dependence. However, these generators often suffer from intermittency and require energy storage when there is over-generation and the subsequent release of this stored energy at high demand. One such energy storage technology that could provide a solution to improving energy management, as well as offering spinning reserve and grid stability, is the redox flow battery (RFB). One such system is the 200 kW/400 kWh vanadium RFB installed in the energy station at Martigny, Switzerland. This RFB utilises the excess energy from renewable generation to support the energy security of the local community, charge electric vehicle batteries, or to provide the power required to an alkaline electrolyser to produce hydrogen as a fuel for use in fuel cell vehicles. In this article, this vanadium RFB is fully characterised in terms of the system and electrochemical energy efficiency, with the focus being placed on areas of internal energy consumption from the regulatory systems and energy losses from self-discharge/side reactions.
      Citation: Batteries
      PubDate: 2018-11-01
      DOI: 10.3390/batteries4040054
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 55: Effect of Operating Temperature on Individual
           Half-Cell Reactions in All-Vanadium Redox Flow Batteries

    • Authors: Ruediger Schweiss, Christian Meiser, Dana Dan
      First page: 55
      Abstract: Systematic steady-state measurements were performed in order to investigate the effect of operating temperature on the individual half-cell reactions in all vanadium redox flow cells. Results confirm that the kinetic losses are dominated by the negative half-cell reaction. Steady-state polarization and AC impedance measurements allowed for extraction of kinetic parameters (exchange current densities, activation energy) of the corresponding half-cell reaction.
      Citation: Batteries
      PubDate: 2018-11-01
      DOI: 10.3390/batteries4040055
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 56: Conversion of Spent Coffee Beans to Electrode
           Material for Vanadium Redox Flow Batteries

    • Authors: Vida Krikstolaityte, Oh En Yao Joshua, Andrei Veksha, Nyunt Wai, Grzegorz Lisak, Tuti Mariana Lim
      First page: 56
      Abstract: This study presents the application of pyrolyzed spent coffee beans as a potential electrode material to replace commercial bipolar graphite plate in vanadium redox flow batteries (VRB). The results indicate that the biochar obtained from spent coffee beans shows relatively good electrochemical charge transfer kinetics of vanadium redox reactions as well as generates higher energy and voltage efficiency in a static cell test when compared to TF6 bipolar graphite plate. Additionally, the biochar was activated via steam at various activation times to increase its surface area, and their effect on the kinetics of the electrochemical reactions was investigated. The activated carbon did not exhibit any improvement neither in electron transfer kinetics nor in the battery efficiency, despite their increased surface area. The performed studies demonstrate that the biochar obtained from spent coffee beans can be a low-cost electrode material for VRB with improved performance characteristics.
      Citation: Batteries
      PubDate: 2018-11-01
      DOI: 10.3390/batteries4040056
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 57: Circular Business Models for Extended EV
           Battery Life

    • Authors: Linda Olsson, Sara Fallahi, Maria Schnurr, Derek Diener, Patricia van Loon
      First page: 57
      Abstract: In the near future, a large volume of electric vehicle (EV) batteries will reach their end-of-life in EVs. However, they may still retain capacity that could be used in a second life, e.g., for a second use in an EV, or for home electricity storage, thus becoming part of the circular economy instead of becoming waste. The aim of this paper is to explore second life of EV batteries to provide an understanding of how the battery value chain and related business models can become more circular. We apply qualitative research methods and draw on data from interviews and workshops with stakeholders, to identify barriers to and opportunities for second use of EV batteries. New business models are conceptualized, in which increased economic viability of second life and recycling and increased business opportunities for stakeholders may lead to reduced resource consumption. The results show that although several stakeholders see potential in second life, there are several barriers, many of which are of an organizational and cognitive nature. The paper concludes that actors along the battery value chain should set up new collaborations with other actors to be able to benefit from creating new business opportunities and developing new business models together.
      Citation: Batteries
      PubDate: 2018-11-02
      DOI: 10.3390/batteries4040057
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 58: Verification of Redox Flow Batteries’
           Functionality by Electrochemical Impedance Spectroscopy Tests

    • Authors: Daniel Manschke, Thorsten Seipp, Sascha Berthold, K. Andreas Friedrich
      First page: 58
      Abstract: The state-of-the-art functionality test of classic redox-flow-stacks measures the current–voltage characteristic with the technical electrolyte. This research paper aims to simplify the validation of redox flow batteries’ functionality by conducting electrochemical impedance spectroscopy (EIS) on redox flow stacks. Since the electrolyte used in the batteries is usually toxic and aggressive, it would be a significant simplification to verify the functionality with an alternative, non-toxic fluid. EIS measurements on batteries with larger sized electrodes, multiple cells, and different fluids were performed. It was demonstrated that all impedances are repeatable, thereby validating this procedure as a qualification method for full-size and complex batteries with an alternative fluid. EIS measurements were able to detect deliberately manipulated cells. This research uses three different analysis methods for the acquired data to identify errors. The respective approaches are, firstly, (1) a comparison of the Nyquist plots; secondly, (2) a comparison of the Bode plots; and thirdly, (3) a comparison of the calculated characteristic values of the equivalent circuits. The analysis found that all methods are suitable to detect errors in the batteries. Nevertheless, the bode-plot comparison method proves to be especially advantageous, because it enables a quantitative statement.
      Citation: Batteries
      PubDate: 2018-11-06
      DOI: 10.3390/batteries4040058
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 59: Heat Loss Measurement of Lithium Titanate
           Oxide Batteries under Fast Charging Conditions by Employing Isothermal

    • Authors: Seyed Saeed Madani, Erik Schaltz, Søren Knudsen Kær
      First page: 59
      Abstract: To understand better the thermal behaviour of lithium-ion batteries under different working conditions, various experiments were applied to a 13 Ah Altairnano lithium titanate oxide battery cell by means of isothermal battery calorimeter. Several parameters were measured such as the battery surface temperature, voltage, current, power, heat flux, maximum temperature and power area. In addition, the efficiency was calculated. Isothermal battery calorimeter was selected as the most appropriate method for heat loss measurements. Temperatures on the surface of the battery were measured by employing four contact thermocouples (type K). In order to determine the heat loss of the battery, constant current charge and discharge pulses at sixteen different C-rates were applied to the battery. It was seen that the charge and discharge C-rates has a considerable influence on the thermal behaviours of lithium-ion batteries. In this research paper, the C-rate was linked to the peak temperature, efficiency and heat loss and it was concluded that they are linear dependent on the C-rate. In addition, the outcomes of this investigation can be used for battery thermal modelling and design of thermal management systems.
      Citation: Batteries
      PubDate: 2018-11-20
      DOI: 10.3390/batteries4040059
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 60: A High Capacity, Room Temperature, Hybrid
           Flow Battery Consisting of Liquid Na-Cs Anode and Aqueous NaI Catholyte

    • Authors: Caihong Liu, Leon Shaw
      First page: 60
      Abstract: In this study, we have proposed a novel concept of hybrid flow batteries consisting of a molten Na-Cs anode and an aqueous NaI catholyte separated by a NaSICON membrane. A number of carbonaceous electrodes are studied using cyclic voltammetry (CV) for their potentials as the positive electrode of the aqueous NaI catholyte. The charge transfer impedance, interfacial impedance and NaSICON membrane impedance of the Na-Cs ‖ NaI hybrid flow battery are analyzed using electrochemical impedance spectroscopy. The performance of the Na-Cs ‖ NaI hybrid flow battery is evaluated through galvanostatic charge/discharge cycles. This study demonstrates, for the first time, the feasibility of the Na-Cs ‖ NaI hybrid flow battery and shows that the Na-Cs ‖ NaI hybrid flow battery has the potential to achieve the following properties simultaneously: (i) An aqueous NaI catholyte with good cycle stability, (ii) a durable and low impedance NaSICON membrane for a large number of cycles, (iii) stable interfaces at both anode/membrane and cathode/membrane interfaces, (iv) a molten Na-Cs anode capable of repeated Na plating and stripping, and (v) a flow battery with high Coulombic efficiency, high voltaic efficiency, and high energy efficiency.
      Citation: Batteries
      PubDate: 2018-11-29
      DOI: 10.3390/batteries4040060
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 61: Sodium Rechargeable Batteries with
           Electrolytes Based on Nafion Membranes Intercalated by Mixtures of Organic

    • Authors: Tatiana Kulova, Alexander Skundin, Andrey Chekannikov, Svetlana Novikova, Daria Voropaeva, Andrey Yaroslavtsev
      First page: 61
      Abstract: The possibilities of manufacturing batteries with Nafion 117 membranes in the Na+-form intercalated by mixtures of non-aqueous organic solvents used both as an electrolyte, separator, and binder were investigated. Electrochemical stability of various organic solvent mixtures based on N,N-dimethylacetamide, ethylene carbonate, propylene carbonate, and tetrahydrofuran were characterized. It was shown that a sodium battery based on a Nafion-Na membrane intercalated by mixture of ethylene carbonate and propylene carbonate with a Na3V1.9Fe0.1(PO4)3/C positive electrode is characterized by a discharge capacity of ≈110 mAh·g−1 (current density of 10 mA·g−1) at room temperature and shows the ability to cycle without degradation during 20 cycles. Batteries with Nafion membrane electrolytes, containing N,N-dimethylacetamide, were characterized using capacity fading during cycling, which is due to the interaction of N,N-dimethylacetamide and a negative sodium electrode.
      Citation: Batteries
      PubDate: 2018-12-01
      DOI: 10.3390/batteries4040061
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 62: Properties of Ion Complexes and Their Impact
           on Charge Transport in Organic Solvent-Based Electrolyte Solutions for
           Lithium Batteries: Insights from a Theoretical Perspective

    • Authors: Jens Smiatek, Andreas Heuer, Martin Winter
      First page: 62
      Abstract: Electrolyte formulations in standard lithium ion and lithium metal batteries are complex mixtures of various components. In this article, we review molecular key principles of ion complexes in multicomponent electrolyte solutions in regards of their influence on charge transport mechanisms. We outline basic concepts for the description of ion–solvent and ion–ion interactions, which can be used to rationalize recent experimental and numerical findings concerning modern electrolyte formulations. Furthermore, we discuss benefits and drawbacks of empirical concepts in comparison to molecular theories of solution for a more refined understanding of ion behavior in organic solvents. The outcomes of our discussion provide a rational for beneficial properties of ions, solvent, co-solvent and additive molecules, and highlight possible routes for further improvement of novel electrolyte solutions.
      Citation: Batteries
      PubDate: 2018-12-03
      DOI: 10.3390/batteries4040062
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 63: Towards Production of a Highly Catalytic and
           Stable Graphene-Wrapped Graphite Felt Electrode for Vanadium Redox Flow

    • Authors: Seyedabolfazl Mousavihashemi, Sebastián Murcia-López, Mir Hosseini, Joan Morante, Cristina Flox
      First page: 63
      Abstract: Despite the appealing features of vanadium redox flow batteries as a promising energy storage solution, the polarization losses, among other factors, prevent widespread applications. The dominant contribution to these polarization losses is the sluggish (even irreversible) electron-transfer towards reactions, leading to large over-potentials (poor rate capability). In particular, the positive half-cell reaction suffers from a complex mechanism since electron- and oxygen-transfer processes are key steps towards efficient kinetics. Thus, the positive reaction calls for electrodes with a large number of active sites, faster electron transfer, and excellent electrical properties. To face this issue, a graphene-wrapped graphite felt (GO-GF) electrode was synthesized by an electrospray process as a cost-effective and straightforward way, leading to a firm control of the GO-deposited layer-by-layer. The voltage value was optimized to produce a homogeneous deposition over a GF electrode after achieving a stable Taylor cone-jet. The GO-GF electrode was investigated by cyclic voltammetry and electrochemical impedance spectroscopy in order to elucidate the electrocatalytic properties. Both analyses reflect this excellent improvement by reducing the over-potentials, improving reversibility, and enhancing collected current density. These findings confirm that the GO-GF is a promising electrode for high-performance VRFB, overcoming the performance-limiting issues in a positive half-reaction.
      Citation: Batteries
      PubDate: 2018-12-03
      DOI: 10.3390/batteries4040063
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 64: Application of Time-Resolved Multi-Sine
           Impedance Spectroscopy for Lithium-Ion Battery Characterization

    • Authors: Hendrik Zappen, Florian Ringbeck, Dirk Uwe Sauer
      First page: 64
      Abstract: Electrochemical Impedance Spectroscopy (EIS) is a valuable tool for the characterization of electrical, thermal and aging behavior of batteries. In this paper, an EIS measurement technique to acquire impedance spectra with high time resolution is examined, which can be used to gather impedance data during dynamic operating conditions. A theoretical analysis of the used multi-sine excitation signals is performed in detail and a practical measurement system is presented and validated. Afterwards, EIS measurements during the charging process of a lithium-ion battery are performed and discussed.
      Citation: Batteries
      PubDate: 2018-12-05
      DOI: 10.3390/batteries4040064
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 65: Main Drivers of Battery Industry Changes:
           Electric Vehicles—A Market Overview

    • Authors: Dmitry V. Pelegov, José Pontes
      First page: 65
      Abstract: The growing popularity of electric vehicles is one of the main drivers of battery industry transformation. Words like “transport system decarbonization”, “electromobility”, and “environmental-friendly society” are very popular today, but questions remain as to how to measure electric vehicles’ adoption progress and how this transition changes the battery industry. This perspective paper provides a review of the electric cars and buses market, estimates the production volumes of some other electric vehicle types, and discusses the role of traction batteries in the global battery market. A simple estimation of the sales rate allows us to evaluate the prospects of electric vehicle adoption in leading countries. Finally, the application of the main battery chemistries is reviewed and topical issues to the research society are addressed and formulated.
      Citation: Batteries
      PubDate: 2018-12-05
      DOI: 10.3390/batteries4040065
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 66: Impact of Water-Based Binder on the
           Electrochemical Performance of P2-Na0.67Mn0.6Fe0.25Co0.1502 Electrodes in
           Na-Ion Batteries

    • Authors: Cyril Marino, Elena Marelli, Sunkyu Park, Claire Villevieille
      First page: 66
      Abstract: Aqueous binders are highly recommended in battery production for (i) reducing the costs and, (ii) increasing the safety due to the absence of an organic solvent. Unfortunately, the impact of water during the electrode formulation on sodiated phases is still unclear and deserves investigation. In this work, we used carboxymethylcellulose (Na-CMC) binder to prepare electrodes of a high energy density P2-layered oxide material, Na0.67Mn0.6Fe0.25Co0.1502 (NaMFC). We investigated the effects of water-based electrode preparation on the electrochemical performance, by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), and neutron diffraction. The water leads to degradation of the material limiting the reversible specific charge at 90 mAh·g−1 instead of 120 mAh·g−1 obtained with N-methyl pyrrolidone (NMP) solvent with polyvinylidene fluoride (PVDF) as binder. The protons exchanged in the structure, occurring during electrode preparation, are assumed to disrupt the Na ions extraction mechanism limiting the specific charge of such a material.
      Citation: Batteries
      PubDate: 2018-12-06
      DOI: 10.3390/batteries4040066
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 67: Thermal Mapping of a Lithium Polymer
           Batteries Pack with FBGs Network

    • Authors: Micael Nascimento, Tiago Paixão, Marta S. Ferreira, João L. Pinto
      First page: 67
      Abstract: In this paper, a network of 37 fiber Bragg grating (FBG) sensors is proposed for real-time, in situ, and operando multipoint monitoring of the surface temperature distribution on a pack of three prismatic lithium polymer batteries (LiPBs). Using the network, a spatial and temporal thermal mapping of all pack interfaces was performed. In each interface, nine strategic locations were monitored by considering a three-by-three matrix, corresponding to the LiPBs top, middle and bottom zones. The batteries were subjected to charge and discharge cycles, where the charge was carried out at 1.0 C, whereas the discharge rates were 0.7 C and 1.4 C. The results show that in general, a thermal gradient is recognized from the top to the bottom, but is less prominent in the end-of-charge steps. The results also indicate the presence of hot spots between two of the three batteries, which were located near the positive tab collector. This occurs due to the higher current density of the lithium ions in this area. The presented FBG sensing network can be used to improve the thermal management of batteries by performing a spatiotemporal thermal mapping, as well as by identifying the zones which are more conducive to the possibility of the existence of hot spots, thereby preventing severe consequences such as thermal runaway and promoting their safety. To our knowledge, this is the first time that a spatial and temporal thermal mapping is reported for this specific application using a network of FBG sensors.
      Citation: Batteries
      PubDate: 2018-12-07
      DOI: 10.3390/batteries4040067
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 68: Electrochemical Performance and Thermal
           Stability of Iron Oxyfluoride (FeOF) for Sodium-Ion Batteries

    • Authors: Ayuko Kitajou, Liwei Zhao, Rintaro Nagano, Atsushi Inoishi, Eiji Kobayashi, Shigeto Okada
      First page: 68
      Abstract: Self-synthesized rutile iron oxyfluoride (FeOF) was studied as a cathode material for Na-ion batteries. The highly crystalline FeOF provided an initial discharge capacity of 246 mAh g−1 in a voltage range of 1.0–4.0 V, followed by 88% of capacity retention after 20 cycles. This discharge-charge reaction of FeOF between 0.8 and 4.0 V are advanced by the Fe2+/Fe3+ redox reaction. That is, no conversion reaction was involved in the application of FeOF as a cathode material for Na-ion batteries because of the low potential of Na-insertion. In addition, the structure change of FeOF from rutile to cubic during Na ion insertion, which was similar to that in Li-ion batteries. No remarkable HF release was detected even up to 700 °C, indicating a low toxic risk of the FeOF cathode. The thermal properties of sodiated and desodiated FeOF electrodes in the associated electrolyte were investigated by DSC (Differential scanning calorimetry) up to 500 °C. Sodiated FeOF electrodes showed larger exothermic heat generation than desodiated ones, especially at a temperature higher than 380 °C. Finally, the thermal stability of FeOF cathodes in the associated Li- and Na-ion battery electrolytes was quantitatively compared with variations of the electrode/electrolyte ratio.
      Citation: Batteries
      PubDate: 2018-12-07
      DOI: 10.3390/batteries4040068
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 69: State of Charge Estimation of Power Battery
           Using Improved Back Propagation Neural Network

    • Authors: Chuan-Wei Zhang, Shang-Rui Chen, Huai-Bin Gao, Ke-Jun Xu, Meng-Yue Yang
      First page: 69
      Abstract: Accurately estimating the state of charge (SOC) of power batteries in electric vehicles is of great significance to the measurement of the endurance mileage of electric vehicles, as well as the safety protection of the power battery. In view of lithium ion batteries’ nonlinear relation between SOC estimation and current, voltage, and temperature, the improved Back Propagation (BP) neural network method is proposed to accurately estimate the SOC of power batteries. To address the inherent limitations of BP neural network, particle swarm algorithm is adopted to modify the relevant weighting coefficients. In this paper, the lithium iron phosphate battery (3.2 V/20 Amper-Hour) was studied. Charge and discharge experiments were conducted under a constant temperature. The training data were used to construct the surrogate model using the improved BP neural network. It is noted that the accuracy of the developed algorithm is increased by 2% as compared to that of conventional BP. Finally, an actual vehicle condition experiment was designed to further verify the accuracy of these two algorithms. The experimental results show that the improved algorithm is more suitable for real vehicle operating conditions than the traditional algorithm, and the estimation accuracy can meet the industry standards to a greater extent.
      Citation: Batteries
      PubDate: 2018-12-11
      DOI: 10.3390/batteries4040069
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 70: Electrochemical Impedance Spectroscopy and
           Determination of the Internal Resistance as a Way to Estimate Lead-Acid
           Batteries Condition

    • Authors: Włodzimierz Majchrzycki, Ewa Jankowska, Marek Baraniak, Piotr Handzlik, Robert Samborski
      First page: 70
      Abstract: Attempts have been made to find the best procedure for the detection of premature battery capacity loss (the so called “PCL”) in AGM-VRLA 48 V batteries operating in telecommunication systems. However, recorded changes in internal resistance and potential did not give clear indications of the beginning of the PCL effect. The obtained correlation between internal resistance and potential derived from used batteries does not show the expected trend in measured parameters. It seems that the application of Electrochemical Impedance Spectroscopy (EIS), which is a faster and non-destructive method, may solve this problem. It is demonstrated that the change in internal resistance (which is an indicator of the state of health (SoH)) can be determined from EIS spectra during continuous operation of 12 V monoblocks in a backup power source of a base transceiver station (BTS).
      Citation: Batteries
      PubDate: 2018-12-12
      DOI: 10.3390/batteries4040070
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 71: Effect of Prelithiation Process for Hard
           Carbon Negative Electrode on the Rate and Cycling Behaviors of Lithium-Ion

    • Authors: Yusuke Abe, Tomoaki Saito, Seiji Kumagai
      First page: 71
      Abstract: Two prelithiation processes (shallow Li-ion insertion, and thrice-repeated deep Li-ion insertion and extraction) were applied to the hard carbon (HC) negative electrode (NE) used in lithium-ion batteries (LIBs). LIB full-cells were assembled using Li(Ni0.5Co0.2Mn0.3)O2 positive electrodes (PEs) and the prelithiated HC NEs. The assembled full-cells were charged and discharged under a low current density, increasing current densities in a stepwise manner, and then constant under a high current density. The prelithiation process of shallow Li-ion insertion resulted in the high Coulombic efficiency (CE) of the full-cell at the initial charge-discharge cycles as well as in a superior rate capability. The prelithiation process of thrice-repeated Li-ion insertion and extraction attained an even higher CE and a high charge-discharge specific capacity under a low current density. However, both prelithiation processes decreased the capacity retention during charge-discharge cycling under a high current density, ascertaining a trade-off relationship between the increased CE and the cycling performance. Further elimination of the irreversible capacity of the HC NE was responsible for the higher utilization of both the PE and NE, attaining higher initial performances, but allowing the larger capacity to fade throughout charge-discharge cycling.
      Citation: Batteries
      PubDate: 2018-12-12
      DOI: 10.3390/batteries4040071
      Issue No: Vol. 4, No. 4 (2018)
  • Batteries, Vol. 4, Pages 30: Application of Robust Design Methodology to
           Battery Packs for Electric Vehicles: Identification of Critical Technical
           Requirements for Modular Architecture

    • Authors: Shashank Arora, Ajay Kapoor, Weixiang Shen
      First page: 30
      Abstract: Modularity-in-design of battery packs for electric vehicles (EVs) is crucial to offset their high manufacturing cost. However, inconsistencies in performance of EV battery packs can be introduced by various sources. Sources of variation affect their robustness. In this paper, parameter diagram, a value-based conceptual analysis approach, is applied to analyze these variations. Their interaction with customer requirements, i.e., ideal system output, are examined and critical engineering features for designing modular battery packs for EV applications are determined. Consequently, sources of variability, which have a detrimental effect on mass-producibility of EV battery packs, are identified and differentiated from the set of control factors. Theoretically, appropriate control level settings can minimize sensitivity of EV battery packs to the sources of variability. In view of this, strength of the relationship between ideal system response and various control factors is studied using a “house of quality” diagram. It is found that battery thermal management system and packaging architecture are the two most influential parameters having the largest effect on reliability of EV battery packs. More importantly, it is noted that heat transfer between adjacent battery modules cannot be eliminated. For successful implementation of modular architecture, it is, therefore, essential that mechanical modularity must be enabled via thermal modularity of EV battery packs.
      Citation: Batteries
      PubDate: 2018-07-02
      DOI: 10.3390/batteries4030030
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 31: Comparison of Battery Architecture

    • Authors: Christophe Savard, Pascal Venet, Éric Niel, Laurent Piétrac, Ali Sari
      First page: 31
      Abstract: This paper presents various solutions for organizing an accumulator battery. It examines three different architectures: series-parallel, parallel-series and C3C architecture, which spread the cell output current flux to three other cells. Alternatively, to improve a several cell system reliability, it is possible to insert more cells than necessary and soliciting them less. Classical RAMS (Reliability, Availability, Maintainability, Safety) solutions can be deployed by adding redundant cells or by tolerating some cell failures. With more cells than necessary, it is also possible to choose active cells by a selection algorithm and place the others at rest. Each variant is simulated for the three architectures in order to determine the impact on battery-operative dependability, that is to say the duration of how long the battery complies specifications. To justify that the conventional RAMS solutions are not deployed to date, this article examines the influence on operative dependability. If the conventional variants allow to extend the moment before the battery stops to be operational, using an algorithm with a suitable optimization criterion further extend the battery mission time.
      Citation: Batteries
      PubDate: 2018-07-03
      DOI: 10.3390/batteries4030031
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 32: Effect of La3+ Modification on the
           Electrochemical Performance of Na3V2(PO4)2F3

    • Authors: Nina V. Kosova, Daria O. Rezepova, Nicolas Montroussier
      First page: 32
      Abstract: La3+ modification of Na3V2(PO4)2F3 was performed by the direct mechanochemically assisted solid-state synthesis of the Na3V2−xLax(PO4)2F3 compositions, and by the LaPO4 coating of the as-prepared Na3V2(PO4)2F3 via the precipitation method. It has been shown that no noticeable substitution of the V3+ ions by the La3+ ions occurs in the Na3V2(PO4)2F3 structure under the synthesis conditions; meanwhile, the introduction of the La3+ ions into the reagent mixture leads to the formation of the LaPO4 phase, and accordingly, an increase in the NaF/VPO4 ratio. The latter results in the formation of the Na3PO4 and Na3VF6 surface impurity phases, which possess high ionic and electronic conductivity, respectively, and significantly enhances the electrical conductivity and the cycling performance of the composite cathode material both in Na and Li cells, while simple surface modification of Na3V2(PO4)2F3 by LaPO4 via precipitation does not.
      Citation: Batteries
      PubDate: 2018-07-09
      DOI: 10.3390/batteries4030032
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 33: Coefficients of Thermal Expansion of Al- and
           Y-Substituted NaSICON Solid Solution Na3+2xAlxYxZr2−2xSi2PO12

    • Authors: Sahir Naqash, Marie-Theres Gerhards, Frank Tietz, Olivier Guillon
      First page: 33
      Abstract: Because of an increasing interest in NaSICON materials as electrolyte materials in all-solid state sodium batteries, their thermal expansion was investigated in this study. The thermal expansion coefficient (CTE) of the Al and Y-substituted NaSICON compositions Na3+2xAlxYxZr2−2xSi2PO12 with 0 ≤ x ≤ 0.3 was obtained by dilatometry and compared to the CTE derived from the lattice parameters using high-temperature X-ray diffraction. The difference in CTE obtained from techniques, the influence of sodium content and central metal cation on CTE, as well as other observations such as phase changes are described and rationalized.
      Citation: Batteries
      PubDate: 2018-07-16
      DOI: 10.3390/batteries4030033
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 34: Factors Affecting the Effectiveness of
           Bioelectrochemical System Applications: Data Synthesis and Meta-Analysis

    • Authors: Simeng Li, Gang Chen
      First page: 34
      Abstract: Microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are promising bioelectrochemical systems (BESs) for simultaneous wastewater treatment and energy/resource recovery. Unlike conventional fuel cells that are based on stable chemical reactions, these BESs are sensitive to environmental and operating conditions, such as temperature, pH, external resistance, etc. Substrate type, electrode material, and reactor configuration are also important factors affecting power generation in MFCs and hydrogen production in MECs. In order to discuss the influence of these above factors on the performance of MFCs and MECs, this study analyzes published data via data synthesis and meta-analysis. The results revealed that domestic wastewater would be more suitable for treatment using MFCs or MECs, due to their lower toxicity for anode biofilms compared to swine wastewater and landfill leachate. The optimal temperature was 25–35 °C, optimal pH was 6–7, and optimal external resistance was 100–1000 Ω. Although systems using carbon cloth as the electrodes demonstrated better performance (due to carbon cloth’s large surface area for microbial growth), the high prices of this material and other existing carbonaceous materials make it inappropriate for practical applications. To scale up and commercialize MFCs and MECs in the future, enhanced system performance and stability are needed, and could be possibly achieved with improved system designs.
      Citation: Batteries
      PubDate: 2018-07-25
      DOI: 10.3390/batteries4030034
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 35: State-of-Charge Monitoring by Impedance
           Spectroscopy during Long-Term Self-Discharge of Supercapacitors and
           Lithium-Ion Batteries

    • Authors: Peter Kurzweil, Mikhail Shamonin
      First page: 35
      Abstract: Frequency-dependent capacitance C(ω) is a rapid and reliable method for the determination of the state-of-charge (SoC) of electrochemical storage devices. The state-of-the-art of SoC monitoring using impedance spectroscopy is reviewed, and complemented by original 1.5-year long-term electrical impedance measurements of several commercially available supercapacitors. It is found that the kinetics of the self-discharge of supercapacitors comprises at least two characteristic time constants in the range of days and months. The curvature of the Nyquist curve at frequencies above 10 Hz (charge transfer resistance) depends on the available electric charge as well, but it is of little use for applications. Lithium-ion batteries demonstrate a linear correlation between voltage and capacitance as long as overcharge and deep discharge are avoided.
      Citation: Batteries
      PubDate: 2018-08-01
      DOI: 10.3390/batteries4030035
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 36: Binding Energy Referencing for XPS in Alkali
           Metal-Based Battery Materials Research (II): Application to Complex
           Composite Electrodes

    • Authors: Steffen Oswald, Franziska Thoss, Martin Zier, Martin Hoffmann, Tony Jaumann, Markus Herklotz, Kristian Nikolowski, Frieder Scheiba, Michael Kohl, Lars Giebeler, Daria Mikhailova, Helmut Ehrenberg
      First page: 36
      Abstract: X-ray photoelectron spectroscopy (XPS) is a key method for studying (electro-)chemical changes in metal-ion battery electrode materials. In a recent publication, we pointed out a conflict in binding energy (BE) scale referencing at alkali metal samples, which is manifested in systematic deviations of the BEs up to several eV due to a specific interaction between the highly reactive alkali metal in contact with non-conducting surrounding species. The consequences of this phenomenon for XPS data interpretation are discussed in the present manuscript. Investigations of phenomena at surface-electrolyte interphase regions for a wide range of materials for both lithium and sodium-based applications are explained, ranging from oxide-based cathode materials via alloys and carbon-based anodes including appropriate reference chemicals. Depending on material class and alkaline content, specific solutions are proposed for choosing the correct reference BE to accurately define the BE scale. In conclusion, the different approaches for the use of reference elements, such as aliphatic carbon, implanted noble gas or surface metals, partially lack practicability and can lead to misinterpretation for application in battery materials. Thus, this manuscript provides exemplary alternative solutions.
      Citation: Batteries
      PubDate: 2018-08-01
      DOI: 10.3390/batteries4030036
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 37: Processing of Advanced Battery
           Materials—Laser Cutting of Pure Lithium Metal Foils

    • Authors: Tobias Jansen, David Blass, Sven Hartwig, Klaus Dilger
      First page: 37
      Abstract: Due to the increasing demand for high-performance cells for mobile applications, the standards of the performance of active materials and the efficiency of cell production strategies are rising. One promising cell technology to fulfill the increasing requirements for actual and future applications are all solid-state batteries with pure lithium metal on the anode side. The outstanding electrochemical material advantages of lithium, with its high theoretical capacity of 3860 mAh/g and low density of 0.534 g/cm3, can only be taken advantage of in all solid-state batteries, since, in conventional liquid electrochemical systems, the lithium dissolves with each discharging cycle. Apart from the current low stability of all solid-state separators, challenges lie in the general processing, as well as the handling and separation, of lithium metal foils. Unfortunately, lithium metal anodes cannot be separated by conventional die cutting processes in large quantities. Due to its adhesive properties and toughness, mechanical cutting tools require intensive cleaning after each cut. The presented experiments show that remote laser cutting, as a contactless and wear-free method, has the potential to separate anodes in large numbers with high-quality cutting edges.
      Citation: Batteries
      PubDate: 2018-08-06
      DOI: 10.3390/batteries4030037
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 38: An Experimental Setup with Alternating
           Current Capability for Evaluating Large Lithium-Ion Battery Cells

    • Authors: Rudi Soares, Alexander Bessman, Oskar Wallmark, Göran Lindbergh, Pontus Svens
      First page: 38
      Abstract: In the majority of applications using lithium-ion batteries, batteries are exposed to some harmonic content apart from the main charging/discharging current. The understanding of the effects that alternating currents have on batteries requires specific characterization methods and accurate measurement equipment. The lack of commercial battery testers with high alternating current capability simultaneously to the ability of operating at frequencies above 200 Hz, led to the design of the presented experimental setup. Additionally, the experimental setup expands the state-of-the-art of lithium-ion batteries testers by incorporating relevant lithium-ion battery cell characterization routines, namely hybrid pulse power current, incremental capacity analysis and galvanic intermittent titration technique. In this paper the hardware and the measurement capabilities of the experimental setup are presented. Moreover, the measurements errors due to the setup’s instruments were analysed to ensure lithium-ion batteries cell characterization quality. Finally, this paper presents preliminary results of capacity fade tests where 28 Ah cells were cycled with and without the injection of 21 A alternating at 1 kHz. Up to 300 cycles, no significant fade in cell capacity may be measured, meaning that alternating currents may not be as harmful for lithium-ion batteries as considered so far.
      Citation: Batteries
      PubDate: 2018-08-13
      DOI: 10.3390/batteries4030038
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 39: Olivine Positive Electrodes for Li-Ion
           Batteries: Status and Perspectives

    • Authors: Alain Mauger, Christian M. Julien
      First page: 39
      Abstract: Among the compounds of the olivine family, LiMPO4 with M = Fe, Mn, Ni, or Co, only LiFePO4 is currently used as the active element of positive electrodes in lithium-ion batteries. However, intensive research devoted to other elements of the family has recently been successful in significantly improving their electrochemical performance, so that some of them are now promising for application in the battery industry and outperform LiFePO4 in terms of energy density, a key parameter for use in electric vehicles in particular. The purpose of this review is to acknowledge the current state of the art and the progress that has been made recently on all the elements of the family and their solid solutions. We also discuss the results from the perspective of their potential application in the industry of Li-ion batteries.
      Citation: Batteries
      PubDate: 2018-08-17
      DOI: 10.3390/batteries4030039
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 40: The Effect of Sulfuric Acid Concentration on
           the Physical and Electrochemical Properties of Vanadyl Solutions

    • Authors: Jamie S. Lawton, Sophia M. Tiano, Daniel J. Donnelly, Sean P. Flanagan, Thomas M. Arruda
      First page: 40
      Abstract: The effects of sulfuric acid concentration in VO2+ solutions were investigated via electrochemical methods and electron paramagnetic resonance. The viscosity of solutions containing 0.01 M VOSO4 in 0.1–7.0 M H2SO4 was measured. Diffusion coefficients were independently measured via electrochemical methods and electron paramagnetic resonance (EPR), with excellent agreement between the techniques employed and literature values. Analysis of cyclic voltammograms suggest the oxidation of VO2+ to VO2+ is quasi-reversible at high H2SO4 concentrations (>5 mol/L), and approaching irreversible at lower H2SO4 concentrations. Further analysis reveals a likely electrochemical/chemical (EC) mechanism where the H2SO4 facilitates the electrochemical step but hinders the chemical step. Fundamental insights of VO2+/H2SO4 solutions can lead to a more comprehensive understanding of the concentration effects in electrolyte solutions.
      Citation: Batteries
      PubDate: 2018-09-01
      DOI: 10.3390/batteries4030040
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 41: A New Glass-Forming Electrolyte Based on
           Lithium Glycerolate

    • Authors: Gioele Pagot, Sara Tonello, Keti Vezzù, Vito Di Noto
      First page: 41
      Abstract: The detailed study of the interplay between the physicochemical properties and the long-range charge migration mechanism of polymer electrolytes able to carry lithium ions is crucial in the development of next-generation lithium batteries. Glycerol exhibits a number of features (e.g., glass-forming behavior, low glass transition temperature, high flexibility of the backbone, and efficient coordination of lithium ions) that make it an appealing ion-conducting medium and a challenging building block in the preparation of new inorganic–organic polymer electrolytes. This work reports the preparation and the extensive investigation of a family of 11 electrolytes based on lithium glycerolate. The electrolytes have the formula C3H5(OH)3−x(OLi)x, where 0 ≤ x ≤ 1. The elemental composition is evaluated by inductively coupled plasma atomic emission spectroscopy. The structure and interactions are studied by vibrational spectroscopies (FT-IR and micro-Raman). The thermal properties are gauged by modulated differential scanning calorimetry and thermogravimetric analysis. Finally, insights on the long-range charge migration mechanism and glycerol relaxation events are investigated via broadband electrical spectroscopy. Results show that in these electrolytes, glycerolate acts as a large and flexible macro-anion, bestowing to the material single-ion conductivity (1.99 × 10−4 at 30 °C and 1.55 × 10−2 S∙cm−1 at 150 °C for x = 0.250).
      Citation: Batteries
      PubDate: 2018-09-01
      DOI: 10.3390/batteries4030041
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 42: Fabrication of a Flexible Current Collector
           for Lithium Ion Batteries by Inkjet Printing

    • Authors: Yuan Gu, John Federici
      First page: 42
      Abstract: A novel chemical process has been developed to formulate injectable nickel ink for conductive film. This chemical method has the ability to remove the oxidation on nickel nano-particle surfaces during ink fabrication; the nickel ions, which are produced during chemical etching, will be reduced and bridged among original nano-nickel particles in the following thermal sintering process at 350 °C. X-ray diffraction results exhibit that the final nickel film has no significant composition change by this chemical method and that oxidation has been effectively removed. Scanning electron microscopy images show that this chemical process reduces nickel oxides into nickel and that the reduced nickel sticks on the original nickel particle surface acting as a “bridge” connecting each particle. So solid diffusion can be triggered easily among bridged nickel particles and sintered at relatively low temperatures. The resistivity of printed film is to 5 × 10 − 6 Ω ∙m which is 71-times that of bulk nickel. The fabricated conductive nickel thin film has been applied on lithium ion batteries as a current collector for cathode and anode and shows good corrosion resistance and stability.
      Citation: Batteries
      PubDate: 2018-09-03
      DOI: 10.3390/batteries4030042
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 43: Impedance Characterization of an
           LCO-NMC/Graphite Cell: Ohmic Conduction, SEI Transport and Charge-Transfer

    • Authors: Victoria Ovejas, Angel Cuadras
      First page: 43
      Abstract: Currently, Li-ion cells are the preferred candidates as energy sources for existing portable applications and for those being developed. Thus, a proper characterization of Li-ion cells is required to optimize their use and their manufacturing process. In this study, the transport phenomena and electrochemical processes taking place in LiCoO2-Li(NiMnCo)O2/graphite (LCO-NMC/graphite) cells are identified from half-cell measurements by means of impedance spectroscopy. The results are calculated from current densities, instead of absolute values, for the future comparison of this data with other cells. In particular, impedance spectra are fitted to simple electrical models composed of an inductive part, serial resistance, and various RQ networks—the parallel combination of a resistor and a constant phase element—depending on the cell. Thus, the evolution of resistances, capacitances, and the characteristic frequencies of the various effects are tracked with the state-of-charge (SoC) at two aging levels. Concretely, two effects are identified at the impedance spectrum; one is clearly caused by the charge transfer at the positive electrode, whereas the other one is presumably caused by the transport of lithium ions across the solid electrolyte interphase (SEI) layer. Moreover, as the cells age, the characteristic frequency of the charge transfer is drastically reduced by a factor of around 70%.
      Citation: Batteries
      PubDate: 2018-09-10
      DOI: 10.3390/batteries4030043
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 44: Investigating the Impact of Particle Size on
           the Performance and Internal Resistance of Aqueous Zinc Ion Batteries with
           a Manganese Sesquioxide Cathode

    • Authors: Christian Bischoff, Oliver Fitz, Christian Schiller, Harald Gentischer, Daniel Biro, Hans-Martin Henning
      First page: 44
      Abstract: Aqueous zinc ion batteries are considered to be one of the most promising battery types for stationary energy storage applications. Due to their aqueous electrolyte, they are inherently safe concerning flammability and environmentally friendly. In this work, the strong influence of the particle size of manganese sesquioxide on the performance of the battery is investigated. Ball milling was used to decrease the particle diameter. The resulting powders were used as active material for the cathodes, which were assembled in coin cells as full cells together with zinc foil anodes and aqueous electrolyte. It was shown that about one third of the original particle size can nearly triple the initial capacity when charged with constant current and constant end-of-charge voltage. Additionally, smaller particles were found to be responsible for the collapse of capacity at high current densities. By means of electrochemical impedance spectroscopy, it was shown that particle size also has a large impact on the internal resistance. Initially, the internal resistance of the cells with small particles was about half that of those with big particles, but became larger during cycling. This reveals accelerated aging processes when the reactive surface of the active material is increased by smaller particles.
      Citation: Batteries
      PubDate: 2018-09-11
      DOI: 10.3390/batteries4030044
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 45: Consumer-Based Evaluation of Commercially
           Available Protected 18650 Cells

    • Authors: Steven Baksa, William Yourey
      First page: 45
      Abstract: Over the past few years, the use of 18650 form factor lithium-ion (Li-ion) cells have transitioned from primarily commercial applications to consumer/residential use. An evaluation of eight commercially available, circuit protected, 18650 form factor Li-ion cells were performed, with analysis focusing on a residential consumer evaluation of performance. As typical consumer cell usage occurs at a relatively low discharge rate, cells were evaluated between 4.2 V and 2.7 V at C/10, C/5, and C/2 discharge rates. The evaluated cells ranged from “high-cost” Panasonic, Hixon, Orbtronic, and EastValley cells to “low-cost” UltraFire (UF) and Eilong cells. Initial discharge comparisons revealed that no cells delivered their nameplate capacity, with a large overstatement of cell capacity occurring for low-cost cells. On average, high-cost cells delivered 92.5% of their advertised capacity, with low-cost cells delivering 20.6% at a C/10 rate. Basing consumer evaluation on a cost per unit capacity and/or cost per unit energy, even with this large overstatement in capacity, low-cost cells still offer an advantage over higher-cost alternatives. The average cost per amp-hour for each cell group ranged from $1.65 to $3.38 for the low-cost and high-cost cell groupings, respectively. Analysis of voltage profiles highlighted two chemistries used in cell production, coinciding with each cell grouping.
      Citation: Batteries
      PubDate: 2018-09-12
      DOI: 10.3390/batteries4030045
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 46: Enhancing the Cycle Life of a Zinc–Air
           Battery by Means of Electrolyte Additives and Zinc Surface Protection

    • Authors: Aroa R. Mainar, Luis C. Colmenares, Hans-Jürgen Grande, J. Alberto Blázquez
      First page: 46
      Abstract: The commercialization of rechargeable alkaline zinc–air batteries (ZAB) requires advanced approaches to improve secondary zinc anode performance, which is hindered by the high corrosion and dissolution rate of zinc in this medium. Modified (with additives) alkaline electrolyte has been one of the most investigated options to reduce the high solubility of zinc. However, this strategy alone has not been fully successful in enhancing the cycle life of the battery. The combination of mitigation strategies into one joint approach, by using additives (ZnO, KF, K2CO3) in the base alkaline electrolyte and simultaneously preparing zinc electrodes that are based on ionomer (Nafion®)-coated zinc particles, was implemented and evaluated. The joint use of electrolyte additives and ionomer coating was intended to regulate the exposition of Zn, deal with zincate solubility, minimize the shape change and dendrite formation, as well as reduce the hydrogen evolution rate. This strategy provided a beneficial joint protective efficiency of 87% thanks to decreasing the corrosion rate from 10.4 (blank) to 1.3 mgZn cm−1·s−1 for coated Zn in the modified electrolyte. Although the rate capability and capacity are limited, the ionomer-coated Zn particles extended the ZAB cycle life by about 50%, providing battery roundtrip efficiency above 55% after 270 h operation.
      Citation: Batteries
      PubDate: 2018-09-13
      DOI: 10.3390/batteries4030046
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 47: Electrocatalysis at Electrodes for
           VanadiumRedox Flow Batteries

    • Authors: Yuping Wu, Rudolf Holze
      First page: 47
      Abstract: Flow batteries (also: redox batteries or redox flow batteries RFB) are briefly introduced as systems for conversion and storage of electrical energy into chemical energy and back. Their place in the wide range of systems and processes for energy conversion and storage is outlined. Acceleration of electrochemical charge transfer for vanadium-based redox systems desired for improved performance efficiency of these systems is reviewed in detail; relevant data pertaining to other redox systems are added when possibly meriting attention. An attempt is made to separate effects simply caused by enlarged electrochemically active surface area and true (specific) electrocatalytic activity. Because this requires proper definition of the experimental setup and careful examination of experimental results, electrochemical methods employed in the reviewed studies are described first.
      Citation: Batteries
      PubDate: 2018-09-13
      DOI: 10.3390/batteries4030047
      Issue No: Vol. 4, No. 3 (2018)
  • Batteries, Vol. 4, Pages 14: On-Demand Micro-Power Generation from an
           Origami-Inspired Paper Biobattery Stack

    • Authors: Maedeh Mohammadifar, Seokheun Choi
      First page: 14
      Abstract: We use origami to create a compact, scalable three-dimensional (3-D) biobattery stack that delivers on-demand energy to the portable biosensors. Folding allows a two-dimensional (2-D) paper sheet possessing predefined functional components to form nine 3-D microbial fuel cells (MFCs), and connect them serially within a small and single unit (5.6 cm × 5.6 cm). We load the biocatalyst Pseudomonas aeruginosa PAO1 in predefined areas that form the MFCs, and freeze-dry them for long-term storage. The biobattery stack generates a maximum power and current of 20 μW and 25 μA, respectively, via microbial metabolism when the freeze-dried cells are rehydrated with readily available wastewater. This work establishes an innovative strategy to revolutionize the fabrication, storage, operation, and application of paper-based MFCs, which could potentially make energy available even in resource-limited settings.
      Citation: Batteries
      PubDate: 2018-03-21
      DOI: 10.3390/batteries4020014
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 15: Prognosis and Remaining Useful Life
           Estimation of Lithium-Ion Battery with Optimal Multi-Level Particle Filter
           and Genetic Algorithm

    • Authors: Chinedu Ossai
      First page: 15
      Abstract: Prognosis and remaining useful life (RUL) estimation of components and systems (C&S) are vital for intelligent asset-integrity management. The implementation of the traditional multi-level particle filter (TRMPF) has improved prognosis when compared with the one-step traditional particle filter that depended on the first-order state equation. However, despite this improvement, the need to enhance the accuracy of fault prognosis, diagnosis and detection cannot be overemphasized. To this end, an optimal multi-level particle filter (OPMPF) algorithm that combines genetic algorithm (GA) optimization and multi-level particle filter (MPF) techniques is used to predict the RUL of the C&S in order to enhance the accuracy of the estimation at different forms of deterioration in operation. A 9-fold cross-validation ensemble MPF that utilized lithium-ion (Li+) batteries’ charge capacity decay to test the developed OPMPF algorithm showed an improvement of over 200% in the estimated RUL when compared with the TRMPF estimation.
      Citation: Batteries
      PubDate: 2018-03-23
      DOI: 10.3390/batteries4020015
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 16: Fast Thermal Runaway Detection for
           Lithium-Ion Cells in Large Scale Traction Batteries

    • Authors: Sascha Koch, Kai Birke, Robert Kuhn
      First page: 16
      Abstract: Thermal runaway of single cells within a large scale lithium-ion battery is a well-known risk that can lead to critical situations if no counter measures are taken in today’s lithium-ion traction batteries for battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEV) and hybrid electric vehicles (HEVs). The United Nations have published a draft global technical regulation on electric vehicle safety (GTR EVS) describing a safety feature to warn passengers in case of a thermal runaway. Fast and reliable detection of faulty cells undergoing thermal runaway within the lithium-ion battery is therefore a key factor in battery designs for comprehensive passenger safety. A set of various possible sensors has been chosen based on the determined cell thermal runaway impact. These sensors have been tested in different sized battery setups and compared with respect to their ability of fast and reliable thermal runaway detection and their feasibility for traction batteries.
      Citation: Batteries
      PubDate: 2018-03-27
      DOI: 10.3390/batteries4020016
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 17: Flexible and Lightweight Lithium-Ion
           Batteries Based on Cellulose Nanofibrils and Carbon Fibers

    • Authors: Huiran Lu, Johan Hagberg, Göran Lindbergh, Ann Cornell
      First page: 17
      Abstract: Flexible, low-weight electrodes with integrated current collectors based on chopped polyacrylonitrile carbon fibers (CF) were produced using an easy, aqueous fabrication process, where only 4 wt% of TEMPO-oxidized cellulose nanofibrils (CNF) were used as the binder. A flexible full cell was assembled based on a LiFePO4 (LFP) positive electrode with a CF current collector and a current collector-free CF negative electrode. The cell exhibited a stable specific capacity of 121 mAh g−1 based on the LFP weight. The CF in the negative electrode acted simultaneously as active material and current collector, which has a significant positive impact on energy density. Stable specific capacities of the CF/CNF negative electrode of 267 mAh g−1 at 0.1 C and 150 mAh g−1 at 1 C are demonstrated. The LFP/CNF with CF/CNF, as the current collector positive electrode (LFP-CF), exhibited a good rate performance with a capacity of ~150 mAh g−1 at 0.1 C and 133 mAh g−1 at 1 C. The polarization of the LFP-CF electrode was similar to that of a commercial Quallion LFP electrode, while much lower compared to a flexible LFP/CNF electrode with Al foil as the current collector. This is ascribed to good contact between the CF and the active material.
      Citation: Batteries
      PubDate: 2018-04-02
      DOI: 10.3390/batteries4020017
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 18: An In-Situ Reference Electrode Insertion
           Method for Commercial 18650-Type Cells

    • Authors: Limhi Somerville, Stefania Ferrari, Michael Lain, Andrew McGordon, Paul Jennings, Rohit Bhagat
      First page: 18
      Abstract: This work introduces a new method for inserting a Lithium reference electrode into commercially available 18650-type cells in order to obtain electrode potentials during cell operation. The proposed method is simple and requires limited equipment. Furthermore, electrical performance is significantly better and the cell capacity and resistance can be recorded for longer durations when compared to some of the previously used methods. Electrical performance of this new third electrode method is characterized and compared to 18650 cells with no reference electrode inserted. The capacity retention of the modified cell is more than 98% in the first 20 cycles. Harvested electrodes from a disassembled cell were also used to make coin cells that was proven to be a rather critical approach to get electrode potentials and capacities. This is an initial study that shows three-electrode performances of a commercial 18650-type cell, which suggests it could be used for understanding electrode behavior throughout a cell lifetime and for manufacturing instrumented cells.
      Citation: Batteries
      PubDate: 2018-04-05
      DOI: 10.3390/batteries4020018
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 19: Real-Time Implementation of an Extended
           Kalman Filter and a PI Observer for State Estimation of Rechargeable
           Li-Ion Batteries in Hybrid Electric Vehicle Applications—A Case Study

    • Authors: Roxana-Elena Tudoroiu, Mohammed Zaheeruddin, Sorin-Mihai Radu, Nicolae Tudoroiu
      First page: 19
      Abstract: The Li-Ion battery state-of-charge estimation is an essential task in a continuous dynamic automotive industry for large-scale and successful marketing of hybrid electric vehicles. Also, the state-of-charge of any rechargeable battery, regardless of its chemistry, is an essential condition parameter for battery management systems of hybrid electric vehicles. In this study, we share from our accumulated experience in the control system applications field some preliminary results, especially in modeling, control and state estimation techniques. We investigate the design and effectiveness of two state-of-charge estimators, namely an extended Kalman filter and a proportional integral observer, implemented in a real-time MATLAB environment for a particular Li-Ion battery. Definitely, the aim of this work is to find the most suitable estimator in terms of estimation accuracy and robustness to changes in initial conditions (i.e., the initial guess value of battery state-of-charge) and changes in process and measurement noise levels. By a rigorous performance analysis of MATLAB simulation results, the potential estimator choice is revealed. The performance comparison can be done visually on similar graphs if the information gathered provides a good insight, otherwise, it can be done statistically based on the calculus of statistic errors, in terms of root mean square error, mean absolute error and mean square error.
      Citation: Batteries
      PubDate: 2018-04-10
      DOI: 10.3390/batteries4020019
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 20: Review of Parameter Determination for Thermal
           Modeling of Lithium Ion Batteries

    • Authors: Seyed Saeed Madani, Erik Schaltz, Søren Knudsen Kær
      First page: 20
      Abstract: This paper reviews different methods for determination of thermal parameters of lithium ion batteries. Lithium ion batteries are extensively employed for various applications owing to their low memory effect, high specific energy, and power density. One of the problems in the expansion of hybrid and electric vehicle technology is the management and control of operation temperatures and heat generation. Successful battery thermal management designs can lead to better reliability and performance of hybrid and electric vehicles. Thermal cycling and temperature gradients could have a considerable impact on the lifetime of lithium ion battery cells. Thermal management is critical in electric vehicles (EVs) and good thermal battery models are necessary to design proper heating and cooling systems. Consequently, it is necessary to determine thermal parameters of a single cell, such as internal resistance, specific heat capacity, entropic heat coefficient, and thermal conductivity in order to design suitable thermal management system.
      Citation: Batteries
      PubDate: 2018-04-20
      DOI: 10.3390/batteries4020020
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 21: Local Study of Lithiation and Degradation
           Paths in LiMn2O4 Battery Cathodes: Confocal Raman Microscopy Approach

    • Authors: Boris Slautin, Denis Alikin, Daniele Rosato, Dmitry Pelegov, Vladimir Shur, Andrei Kholkin
      First page: 21
      Abstract: Lithium manganese-based cathodes are widely used in rechargeable batteries due to their low cost, safety, and ecological stability. On the other hand, fast capacity fade occurs in LiMn2O4 mainly because of the induced manganese dissolution and formation of additional phases. Confocal Raman microscopy provides many opportunities for sensitive and spatially resolved structural studies of micro- and nanoscale phenomena. Here, we demonstrate advantages of confocal Raman spectroscopy approach for uncovering the mechanisms of lithiation/delithiation and degradation in LiMn2O4 commercial cathodes. The analysis of Raman spectra for inspecting local lithiation state and phase composition is proposed and exploited for the visualization of the inhomogeneous distribution of lithium ions. The cycling of cathodes is shown to be followed by the formation and dissolution of the Mn3O4 phase and local disturbance of the lithiation state. These processes are believed to be responsible for the capacity fade in the commercial batteries.
      Citation: Batteries
      PubDate: 2018-05-01
      DOI: 10.3390/batteries4020021
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 22: Nontrivial Effects of “Trivial”
           Parameters on the Performance of Lithium–Sulfur Batteries

    • Authors: Junbin Liao, Zhibin Ye
      First page: 22
      Abstract: A robust lithium-sulfur (Li–S) battery is constituted by a wide range of optimized fundamental parameters (e.g., amount of electrolyte, electrolyte additive, sulfur loading density, and the size of sulfur particles). In this paper, some other often-neglected “trivial” parameters (including assembly pressure of the coil cells, thickness of spring/lithium foil in coin cells, sheet number of separator, and cut-off voltage) of Li–S batteries have been demonstrated to show pronounced effects on the battery performance. Our results indicate that the coin cell assembly pressure and sheet number of the separator play the important roles in suppressing polysulfide shuttling over battery cycling, which improves significantly the cycling life of Li–S batteries. The thickness of springs/lithium foils also affects the battery performance greatly. When switching the cut-off voltage of 1.5–3.0 V to narrower ones (1.7–2.5 V or 1.8–2.6 V), the cycling life of batteries at 0.2 C can be further enhanced to >300 cycles while with no drastic polysulfide shuttling. Adjusting these trivial parameters can thus synergistically improve the cycling performance of Li–S batteries.
      Citation: Batteries
      PubDate: 2018-05-02
      DOI: 10.3390/batteries4020022
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 23: Simultaneous Sensing of Temperature and
           Bi-Directional Strain in a Prismatic Li-Ion Battery

    • Authors: Micael Nascimento, Marta S. Ferreira, João L. Pinto
      First page: 23
      Abstract: Thermal and pressure stability of Li-ion batteries (LiB) are the most important parameters for safety. In abuse operating conditions, the rapid increase of temperature and pressure can cause the appearance of hot-spots, which may lead to an increasing degradation rate or even to the battery’s explosion and/or combustion. A sensing network of fiber Bragg gratings is attached to the surface of a prismatic LiB to monitor its temperature and bi-directional strain variations through normal charge (0.70 C) and two different discharge rates (1.32 C and 5.77 C) in the x- and y-directions. More significant variations are registered when the LiB operates in abnormal conditions. A maximum temperature variation of 27.52 ± 0.13 °C is detected by the sensors located close to the positive electrode side. Regarding strain and consequent length variations, maximum values of 593.58 ± 0.01 µε and 51.05 ± 0.05 µm are respectively obtained by the sensors placed on the y-direction. The sensing network presented can be a solution for the real-time monitoring, multipoint and in operando temperature and bi-directional strain variations in the LiBs, promoting their safety.
      Citation: Batteries
      PubDate: 2018-05-10
      DOI: 10.3390/batteries4020023
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 24: High-Yield Preparation of ZnO Nanoparticles
           on Exfoliated Graphite as Anode Material for Lithium Ion Batteries and the
           Effect of Particle Size as well as of Conductivity on the Electrochemical
           Performance of Such Composites

    • Authors: Olga Isakin, Stephanie Hiltl, Oliver Struck, Monika Willert-Porada, Ralf Moos
      First page: 24
      Abstract: The combination of zinc oxide (ZnO) nanoparticles (NP) and graphite provides a promising approach for applications in the field of anode materials for lithium ion batteries. Here, we report a facile and environmentally friendly method yielding uniformly dispersed ZnO particles with a controllable particle size between 5 and 80 nm, supported by exfoliated graphite (EG) sheets. A thermal post-treatment (420 to 800 °C, N2) of ZnO@EG composite results in high yield with the opportunity for industrial scale-up. The post-treatment leads to growing ZnO particles on the EG sheets, while oxygen is disincorporated from ZnO by the associated carbothermal reduction of ZnO@EG composites above 600 °C and the conductivity is increased. ZnO@EG composite anodes, reduced at 600 °C, show improved Li storage capacity (+25%) and good cycle stability, compared to the EG anode. This can be attributed to the increased conductivity, despite the particle size increased up to 80 nm. Furthermore, we suggest that the mechanism for the reaction of Li+ ions with ZnO@EG-composites including ZnO-particles with an average particle size below 20 nm differs from the classical Li+ ions insertion/de-insertion or alloying process.
      Citation: Batteries
      PubDate: 2018-05-23
      DOI: 10.3390/batteries4020024
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 25: The Electrochemical Sodiation of Sb
           Investigated by Operando X-ray Absorption and 121Sb Mössbauer
           Spectroscopy: What Does One Really Learn'

    • Authors: Ali Darwiche, Marcus Fehse, Abdelfattah Mahmoud, Camille La Fontaine, Bernard Fraisse, Raphael P. Hermann, Marie-Liesse Doublet, Laure Monconduit, Moulay T. Sougrati, Mouna Ben Yahia, Lorenzo Stievano
      First page: 25
      Abstract: In this study, we want to highlight the assets and restrictions of X-ray absorption spectroscopy (XAS) and Mössbauer spectroscopy for investigating the mechanism of the electrochemical reaction of antimony electrode materials vs. Na. For this, operando XAS was carried out during the first one and a half cycles, and the whole set of measured data was analysed using a statistical-chemometric approach, while low temperature Mössbauer spectroscopy measurements were carried out ex situ on selected samples stopped at different points of the electrochemical reaction. Complementary ab initio calculations were performed to support the experimental findings. Both techniques show that, upon the first sodiation, most Sb reacts with Na to form disordered Na 3 Sb. This step is accompanied by the formation of amorphous Sb as an intermediate. Upon inversion of the current Na 3 Sb is desodiated and an amorphous Sb phase, distinct from the pristine bulk Sb state, is gradually formed. However, both XAS and Mössbauer spectroscopy were unable to spot the formation of intermediate Na x Sb phases, which were evinced in previous works by operando Pair Distribution Function analyses. The results shown here clearly assign such failure to the intrinsic inability of both techniques to identify these intermediates.
      Citation: Batteries
      PubDate: 2018-05-30
      DOI: 10.3390/batteries4020025
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 26: Formation and Stability of Interface between
           Garnet-Type Ta-doped Li7La3Zr2O12 Solid Electrolyte and Lithium Metal

    • Authors: Ryoji Inada, Satoshi Yasuda, Hiromasa Hosokawa, Masaya Saito, Tomohiro Tojo, Yoji Sakurai
      First page: 26
      Abstract: Garnet-type Li7-xLa3Zr2-xTaxO12 (LLZT) is considered a good candidate for the solid electrolyte in all-solid-state lithium batteries because of its reasonably high conductivity around 10−3 S cm−1 at room temperature and stability against lithium (Li) metal with the lowest redox potential. In this study, we synthesized LLZT with a tantalum (Ta) content of 0.45 via a conventional solid-state reaction process and constructed a Li/LLZT/Li symmetric cell by attaching Li metal foils on the polished top and bottom surfaces of an LLZT pellet. We investigated the influence of heating temperatures and times on the interfacial charge-transfer resistance between LLZT and the Li metal electrode. In addition, the effect of the interface resistance on the stability for Li deposition and dissolution was examined using a galvanostatic cycling test. The lowest interfacial resistance of 25 Ω cm2 at room temperature was obtained by heating at 175 °C (5 °C lower than the melting point of Li) for three to five hours. We confirmed that the current density at which the short circuit occurs in the Li/LLZT/Li cell via the propagation of Li dendrite into LLZT increases with decreasing interfacial charge transfer resistance.
      Citation: Batteries
      PubDate: 2018-06-07
      DOI: 10.3390/batteries4020026
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 27: Introduction of Electric Vehicle Charging
           Stations to University Campuses: A Case Study for the University of
           Georgia from 2014 to 2017

    • Authors: Sierra Hovet, Blair Farley, Jason Perry, Kevin Kirsche, Michael Jerue, Zion Tsz Ho Tse
      First page: 27
      Abstract: Electric vehicles (EVs) are becoming increasingly popular in the United States of America (USA). EVs attract buyers with benefits including energy efficiency and environmental friendliness. As EV usage grows, more public spaces are installing EV charging stations. This paper presents a comprehensive analysis of EV charging station usage at the University of Georgia (UGA) in Athens, Georgia. Three ChargePoint EV charging stations at UGA were used to collect data about each of 3204 charging events that occurred from 10 April 2014 to 20 June 2017. The charging event data included start date, start time, length of parking time, length of charging time, amount of energy delivered, and the postal code entered by the user during ChargePoint account registration. Analytical methods were proposed to obtain information about EV charging behavior, charging station occupancy, and geolocation of charging station users. The methodology presented here was time- and cost-effective, as well as scalable to other organizations that own charging stations. Because this study took place at a university, the results presented here can be used as a reference for EV charging station usage in other college towns in the USA that do not have EV charging stations but are planning to develop EV infrastructure.
      Citation: Batteries
      PubDate: 2018-06-07
      DOI: 10.3390/batteries4020027
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 28: Ion Transport in Solvent-Free, Crosslinked,

    • Authors: Clay T. Elmore, Morgan E. Seidler, Hunter O. Ford, Laura C. Merrill, Sunil P. Upadhyay, William F. Schneider, Jennifer L. Schaefer
      First page: 28
      Abstract: Solvent-free, single-ion conducting electrolytes are sought after for use in electrochemical energy storage devices. Here, we investigate the ionic conductivity and how this property is influenced by segmental mobility and conducting ion number in crosslinked single-ion conducting polyether-based electrolytes with varying tethered anion and counter-cation types. Crosslinked electrolytes are prepared by the polymerization of poly(ethylene glycol) diacrylate (PEGDA), poly(ethylene glycol) methyl ether acrylate, and ionic monomers. The ionic conductivity of the electrolytes is measured and interpreted in the context of differential scanning calorimetry and Raman spectroscopy measurements. A lithiated crosslinked electrolyte prepared with PEG31DA and (4-styrenesulfonyl)(trifluoromethanesulfonyl)imide (STFSI) monomers is found to have a lithium ion conductivity of 3.2 × 10−6 and 1.8 × 10−5 S/cm at 55 and 100 °C, respectively. The percentage of unpaired anions for this electrolyte was estimated at about 23% via Raman spectroscopy. Despite the large variances in metal cation–STFSI binding energies as predicted via density functional theory (DFT) and large variations in ionic conductivity, STFSI-based crosslinked electrolytes with the same charge density and varying cations (Li, Na, K, Mg, and Ca) were estimated to all have unpaired anion populations in the range of 19 to 29%.
      Citation: Batteries
      PubDate: 2018-06-07
      DOI: 10.3390/batteries4020028
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 29: Development of an Electro-Thermal Model for
           Electric Vehicles Using a Design of Experiments Approach

    • Authors: Manoj Mathew, Mehrdad Mastali, John Catton, Ehsan Samadani, Stefan Janhunen, Michael Fowler
      First page: 29
      Abstract: An accurate and computationally efficient lithium-ion battery model is beneficial when developing state-of-charge (SOC) and state-of-health (SOH) algorithms for battery management systems (BMS). These models allow for software-in-the-loop (SIL) and hardware-in-the-loop (HIL) testing, where the battery pack is simulated in software. However, development of these battery models can be time-consuming, especially when trying to model the effects of temperature and SOC on the equivalent circuit model (ECM) parameters. Estimation of this relationship is often accomplished by carrying out many experiments, which can be costly and time consuming for BMS manufacturers. To address these issues, this paper makes two contributions to literature. First, a comprehensive battery model is developed, where the ECM parameter surface is generated using a design of experiments (DOE) approach. Second, replication runs are conducted to accurately estimate the measurement noise and determine which model parameters are significant. The technique is then compared with existing approaches from the literature, and it is shown that, by using the proposed method, the same degree of accuracy can be obtained while requiring significantly fewer experimental runs. This can be advantageous for BMS manufacturers that require a high-fidelity model but cannot afford to carry out many experiments.
      Citation: Batteries
      PubDate: 2018-06-18
      DOI: 10.3390/batteries4020029
      Issue No: Vol. 4, No. 2 (2018)
  • Batteries, Vol. 4, Pages 2: Towards Li-Ion Batteries Operating at 80 °C:
           Ionic Liquid versus Conventional Liquid Electrolytes

    • Authors: Gabriel Oltean, Nareerat Plylahan, Charlotte Ihrfors, Wei Wei, Chao Xu, Kristina Edström, Leif Nyholm, Patrik Johansson, Torbjörn Gustafsson
      First page: 2
      Abstract: Li-ion battery (LIB) full cells comprised of TiO2-nanotube (TiO2-nt) and LiFePO4 (LFP) electrodes and either a conventional organic solvent based liquid electrolyte or an ionic liquid based electrolyte have been cycled at 80 °C. While the cell containing the ionic liquid based electrolyte exhibited good capacity retention and rate capability during 100 cycles, rapid capacity fading was found for the corresponding cell with the organic electrolyte. Results obtained for TiO2-nt and LFP half-cells indicate an oxidative degradation of the organic electrolyte at 80 °C. In all, ionic liquid based electrolytes can be used to significantly improve the performance of LIBs operating at 80 °C.
      Citation: Batteries
      PubDate: 2018-01-02
      DOI: 10.3390/batteries4010002
      Issue No: Vol. 4, No. 1 (2018)
  • Batteries, Vol. 4, Pages 3: Looking Deeper into the Galaxy (Note 7)

    • Authors: Melanie Loveridge, Guillaume Remy, Nadia Kourra, Ronny Genieser, Anup Barai, Mike Lain, Yue Guo, Mark Amor-Segan, Mark Williams, Tazdin Amietszajew, Mark Ellis, Rohit Bhagat, David Greenwood
      First page: 3
      Abstract: Li-ion cell designs, component integrity, and manufacturing processes all have critical influence on the safety of Li-ion batteries. Any internal defective features that induce a short circuit, can trigger a thermal runaway: a cascade of reactions, leading to a device fire. As consumer device manufacturers push aggressively for increased battery energy, instances of field failure are increasingly reported. Notably, Samsung made a press release in 2017 following a total product recall of their Galaxy Note 7 mobile phone, confirming speculation that the events were attributable to the battery and its mode of manufacture. Recent incidences of battery swelling on the new iPhone 8 have been reported in the media, and the techniques and lessons reported herein may have future relevance. Here we look deeper into the key components of one of these cells and confirm evidence of cracking of electrode material in tightly folded areas, combined with a delamination of surface coating on the separator, which itself is an unusually thin monolayer. We report microstructural information about the electrodes, battery welding attributes, and thermal mapping of the battery whilst operational. The findings present a deeper insight into the battery’s component microstructures than previously disseminated. This points to the most probable combination of events and highlights the impact of design features, whilst providing structural considerations most likely to have led to the reported incidences relating to this phone.
      Citation: Batteries
      PubDate: 2018-01-08
      DOI: 10.3390/batteries4010003
      Issue No: Vol. 4, No. 1 (2018)
  • Batteries, Vol. 4, Pages 4: Pre-Lithiation Strategies for Rechargeable
           Energy Storage Technologies: Concepts, Promises and Challenges

    • Authors: Florian Holtstiege, Peer Bärmann, Roman Nölle, Martin Winter, Tobias Placke
      First page: 4
      Abstract: In order to meet the sophisticated demands for large-scale applications such as electro-mobility, next generation energy storage technologies require advanced electrode active materials with enhanced gravimetric and volumetric capacities to achieve increased gravimetric energy and volumetric energy densities. However, most of these materials suffer from high 1st cycle active lithium losses, e.g., caused by solid electrolyte interphase (SEI) formation, which in turn hinder their broad commercial use so far. In general, the loss of active lithium permanently decreases the available energy by the consumption of lithium from the positive electrode material. Pre-lithiation is considered as a highly appealing technique to compensate for active lithium losses and, therefore, to increase the practical energy density. Various pre-lithiation techniques have been evaluated so far, including electrochemical and chemical pre-lithiation, pre-lithiation with the help of additives or the pre-lithiation by direct contact to lithium metal. In this review article, we will give a comprehensive overview about the various concepts for pre lithiation and controversially discuss their advantages and challenges. Furthermore, we will critically discuss possible effects on the cell performance and stability and assess the techniques with regard to their possible commercial exploration.
      Citation: Batteries
      PubDate: 2018-01-23
      DOI: 10.3390/batteries4010004
      Issue No: Vol. 4, No. 1 (2018)
  • Batteries, Vol. 4, Pages 5: A Review of Model-Based Design Tools for
           Metal-Air Batteries

    • Authors: Simon Clark, Arnulf Latz, Birger Horstmann
      First page: 5
      Abstract: The advent of large-scale renewable energy generation and electric mobility is driving a growing need for new electrochemical energy storage systems. Metal-air batteries, particularly zinc-air, are a promising technology that could help address this need. While experimental research is essential, it can also be expensive and time consuming. The utilization of well-developed theory-based models can improve researchers’ understanding of complex electrochemical systems, guide development, and more efficiently utilize experimental resources. In this paper, we review the current state of metal-air batteries and the modeling methods that can be implemented to advance their development. Microscopic and macroscopic modeling methods are discussed with a focus on continuum modeling derived from non-equilibrium thermodynamics. An applied example of zinc-air battery engineering is presented.
      Citation: Batteries
      PubDate: 2018-01-29
      DOI: 10.3390/batteries4010005
      Issue No: Vol. 4, No. 1 (2018)
  • Batteries, Vol. 4, Pages 6: Acknowledgement to Reviewers of Batteries in

    • Authors: Batteries Editorial Office
      First page: 6
      Abstract: Peer review is an essential part in the publication process, ensuring that Batteries maintains high quality standards for its published papers.
      Citation: Batteries
      PubDate: 2018-01-30
      DOI: 10.3390/batteries4010006
      Issue No: Vol. 4, No. 1 (2018)
  • Batteries, Vol. 4, Pages 7: Current Advances in TiO2-Based Nanostructure
           Electrodes for High Performance Lithium Ion Batteries

    • Authors: Mahmoud Madian, Alexander Eychmüller, Lars Giebeler
      First page: 7
      Abstract: The lithium ion battery (LIB) has proven to be a very reliably used system to store electrical energy, for either mobile or stationary applications. Among others, TiO2-based anodes are the most attractive candidates for building safe and durable lithium ion batteries with high energy density. A variety of TiO2 nanostructures has been thoroughly investigated as anodes in LIBs, e.g., nanoparticles, nanorods, nanoneedles, nanowires, and nanotubes discussed either in their pure form or in composites. In this review, we present the recent developments and breakthroughs demonstrated to synthesize safe, high power, and low cost nanostructured titania-based anodes. The reader is provided with an in-depth review of well-oriented TiO2-based nanotubes fabricated by anodic oxidation. Other strategies for modification of TiO2-based anodes with other elements or materials are also highlighted in this report.
      Citation: Batteries
      PubDate: 2018-02-06
      DOI: 10.3390/batteries4010007
      Issue No: Vol. 4, No. 1 (2018)
  • Batteries, Vol. 4, Pages 8: High-Performance Na0.44MnO2 Slabs for
           Sodium-Ion Batteries Obtained through Urea-Based Solution Combustion

    • Authors: Chiara Ferrara, Cristina Tealdi, Valentina Dall’Asta, Daniel Buchholz, Luciana Chagas, Eliana Quartarone, Vittorio Berbenni, Stefano Passerini
      First page: 8
      Abstract: One of the primary targets of current research in the field of energy storage and conversion is the identification of easy, low-cost approaches for synthesizing cell active materials. Herein, we present a novel method for preparing nanometric slabs of Na0.44MnO2, making use of the eco-friendly urea within a solution synthesis approach. This kind of preparation greatly reduces the time of reaction, decreases the thermal treatment temperature, and allows the obtaining of particles with smaller dimensions compared with those obtained through conventional solid-state synthesis. Such a decrease in particle size guarantees improved electrochemical performance, particularly at high current densities, where kinetic limitations become relevant. Indeed, the materials produced via solution synthesis outperform those prepared via solid-state synthesis both at 2 C, (95 mA h g−1 vs. 85 mA h g−1, respectively) and 5 C, (78 mA h g−1 vs. 68.5 mA h g−1, respectively). Additionally, the former material is rather stable over 200 cycles, with a high capacity retention of 75.7%.
      Citation: Batteries
      PubDate: 2018-02-09
      DOI: 10.3390/batteries4010008
      Issue No: Vol. 4, No. 1 (2018)
  • Batteries, Vol. 4, Pages 9: Research in Nickel/Metal Hydride Batteries

    • Authors: Kwo-Hsiung Young
      First page: 9
      Abstract: Continuing from a special issue in Batteries in 2016, nineteen new papers focusing on recent research activities in the field of nickel/metal hydride (Ni/MH) batteries have been selected for the 2017 Special Issue of Ni/MH Batteries. These papers summarize the international joint-efforts in Ni/MH battery research from BASF, Wayne State University, Michigan State University, FDK Corp. (Japan), Institute for Energy Technology (Norway), Central South University (China), University of Science and Technology Beijing (China), Zhengzhou University of Light Industry (China), Inner Mongolia University of Science and Technology (China), Shenzhen Highpower (China), and University of the Witwatersrand (South Africa) from 2016–2017 through reviews of AB2 metal hydride alloys, Chinese and EU Patent Applications, as well as descriptions of research results in metal hydride alloys, nickel hydroxide, electrolyte, and new cell type, comparison work, and projections of future works.
      Citation: Batteries
      PubDate: 2018-02-12
      DOI: 10.3390/batteries4010009
      Issue No: Vol. 4, No. 1 (2018)
  • Batteries, Vol. 4, Pages 10: Pyrrolidinium FSI and TFSI-Based Polymerized
           Ionic Liquids as Electrolytes for High-Temperature Lithium-Ion Batteries

    • Authors: Manfred Kerner, Patrik Johansson
      First page: 10
      Abstract: Promising electrochemical and dynamical properties, as well as high thermal stability, have been the driving forces behind application of ionic liquids (ILs) and polymerized ionic liquids (PILs) as electrolytes for high-temperature lithium-ion batteries (HT-LIBs). Here, several ternary lithium-salt/IL/PIL electrolytes (PILel) have been investigated for synergies of having both FSI and TFSI anions present, primarily in terms of physico-chemical properties, for unique application in HT-LIBs operating at 80 °C. All of the electrolytes tested have low Tg and are thermally stable ≥100 °C, and with TFSI as the exclusive anion the electrolytes (set A) have higher thermal stabilities ≥125 °C. Ionic conductivities are in the range of 1 mS/cm at 100 °C and slightly higher for set A PILel, which, however, have lower oxidation stabilities than set B PILel with both FSI and TFSI anions present: 3.4–3.7 V vs. 4.2 V. The evolution of the interfacial resistance increases for all PILel during the first 40 h, but are much lower for set B PILel and generally decrease with increasing Li-salt content. The higher interfacial resistances only influence the cycling performance at high C-rates (1 C), where set B PILel with high Li-salt content performs better, while the discharge capacities at the 0.1 C rate are comparable. Long-term cycling at 0.5 C, however, shows stable discharge capacities for 100 cycles, with the exception of the set B PILel with high Li-salt content. Altogether, the presence of both FSI and TFSI anions in the PILel results in lower ionic conductivities and decreased thermal stabilities, but also higher oxidation stabilities and reduced interfacial resistances and, in total, result in an improved rate capability, but compromised long-term capacity retention. Overall, these electrolytes open for novel designs of HT-LIBs.
      Citation: Batteries
      PubDate: 2018-02-13
      DOI: 10.3390/batteries4010010
      Issue No: Vol. 4, No. 1 (2018)
  • Batteries, Vol. 4, Pages 11: Li-NMC Batteries Model Evaluation with
           Experimental Data for Electric Vehicle Application

    • Authors: Aleksandra Baczyńska, Waldemar Niewiadomski, Ana Gonçalves, Paulo Almeida, Ricardo Luís
      First page: 11
      Abstract: The aim of the paper is to present the battery equivalent circuit for electric vehicle application. Moreover, the model described below is dedicated to lithium-ion types of batteries. The purpose of this paper is to introduce an efficient and transparent method to develop a battery equivalent circuit model. Battery modeling requires, depending on the chosen method, either significant calculations or a highly developed mathematical model for optimization. The model is evaluated in comparison to the real data measurements, to present the performance of the method. Battery measurements based on charge/discharge tests at a fixed C-rate are presented to show the relation of the output voltage profiles with the battery state of charge. The pulse discharge test is presented to obtain the electric parameters of the battery equivalent circuit model, using a Thévenin circuit. According to the Reverse Trike Ecologic Electric Vehicle (VEECO RT) characteristics used as a case study in this work, new values for vehicle autonomy and battery pack volume based on lithium nickel manganese cobalt oxide cells are evaluated.
      Citation: Batteries
      PubDate: 2018-02-13
      DOI: 10.3390/batteries4010011
      Issue No: Vol. 4, No. 1 (2018)
  • Batteries, Vol. 4, Pages 12: Mechanical Coating of Zinc Particles with
           Bi2O3-Li2O-ZnO Glasses as Anode Material for Rechargeable Zinc-Based

    • Authors: Tobias Michlik, Manuela Schmid, Andreas Rosin, Thorsten Gerdes, Ralf Moos
      First page: 12
      Abstract: The electrochemical performance of zinc particles with 250 μm and 30 μm diameters, coated with Bi2O3-Li2O-ZnO glass is investigated and compared with noncoated zinc particles. Galvanostatic investigations were conducted in the form of complete discharge and charging cycles in electrolyte excess. Coated 30 μm zinc particles provide the best rechargeability after complete discharge. The coatings reached an average charge capacity over 20 cycles of 113 mAh/g compared to the known zero rechargeability of uncoated zinc particles. Proposed reasons for the prolonged cycle life are effective immobilization of discharge products in the glass layer and the formation of percolating metallic bismuth and zinc phases, forming a conductive network through the glass matrix. The coating itself is carried out by mechanical ball milling. Different coating parameters and the resulting coating quality as well as their influence on the passivation and on the rechargeability of zinc–glass composites is investigated. Optimized coating qualities with respect to adhesion, homogeneity and compactness of the glass layer are achieved at defined preparation conditions, providing a glass coating content of almost 5 wt % for 250 μm zinc particles and almost 11 wt % for 30 μm zinc particles.
      Citation: Batteries
      PubDate: 2018-02-23
      DOI: 10.3390/batteries4010012
      Issue No: Vol. 4, No. 1 (2018)
  • Batteries, Vol. 4, Pages 13: Untreated Natural Graphite as a Graphene
           Source for High-Performance Li-Ion Batteries

    • Authors: María Simón, Almudena Benítez, Alvaro Caballero, Julián Morales, Oscar Vargas
      First page: 13
      Abstract: Graphene nanosheets (GNS) are synthesized from untreated natural graphite (NG) for use as electroactive materials in Li-ion batteries (LIBs), which avoids the pollution-generating steps of purifying graphite. Through a modified Hummer method and subsequent thermal exfoliation, graphitic oxide and graphene were synthesized and characterized structurally, morphologically and chemically. Untreated natural graphite samples contain 45–50% carbon by weight; the rest is composed of different elements such as aluminium, calcium, iron, silicon and oxygen, which are present as calcium carbonate and silicates of aluminium and iron. Our results confirm that in the GO and GNS synthesized, calcium is removed due to oxidation, though other impurities are maintained because they are not affected by the synthesis. Despite the remaining mineral phases, the energy storage capacity of GNS electrodes is very promising. In addition, an electrochemical comparison between GNS and NG demonstrated that the specific capacity in GNS is higher during the whole cycling process, 770 mA·g−1 at 100th cycle, which is twice that of graphite.
      Citation: Batteries
      PubDate: 2018-03-01
      DOI: 10.3390/batteries4010013
      Issue No: Vol. 4, No. 1 (2018)
School of Mathematical and Computer Sciences
Heriot-Watt University
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