Subjects -> ENGINEERING (Total: 2844 journals)
    - CHEMICAL ENGINEERING (259 journals)
    - CIVIL ENGINEERING (255 journals)
    - ELECTRICAL ENGINEERING (182 journals)
    - ENGINEERING (1420 journals)
    - ENGINEERING MECHANICS AND MATERIALS (454 journals)
    - HYDRAULIC ENGINEERING (60 journals)
    - INDUSTRIAL ENGINEERING (101 journals)
    - MECHANICAL ENGINEERING (113 journals)

ENGINEERING (1420 journals)                  1 2 3 4 5 6 7 8 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 9)
3D Research     Hybrid Journal   (Followers: 22)
AAPG Bulletin     Hybrid Journal   (Followers: 11)
Abstract and Applied Analysis     Open Access   (Followers: 4)
Aceh International Journal of Science and Technology     Open Access   (Followers: 9)
ACS Nano     Hybrid Journal   (Followers: 452)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 10)
Acta Nova     Open Access   (Followers: 1)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 4)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access   (Followers: 1)
Active and Passive Electronic Components     Open Access   (Followers: 8)
Adaptive Behavior     Hybrid Journal   (Followers: 9)
Adsorption     Hybrid Journal   (Followers: 5)
Advanced Energy and Sustainability Research     Open Access   (Followers: 8)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 14)
Advanced Engineering Research     Open Access  
Advanced Journal of Graduate Research     Open Access   (Followers: 4)
Advanced Quantum Technologies     Hybrid Journal   (Followers: 1)
Advanced Science     Open Access   (Followers: 13)
Advanced Science Focus     Free   (Followers: 7)
Advanced Science Letters     Full-text available via subscription   (Followers: 13)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 11)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 20)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 5)
Advances in Catalysis     Full-text available via subscription   (Followers: 8)
Advances in Complex Systems     Hybrid Journal   (Followers: 12)
Advances in Engineering Software     Hybrid Journal   (Followers: 31)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 20)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 22)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 30)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 27)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 10)
Advances in Natural Sciences : Nanoscience and Nanotechnology     Open Access   (Followers: 36)
Advances in Operations Research     Open Access   (Followers: 14)
Advances in OptoElectronics     Open Access   (Followers: 6)
Advances in Physics Theories and Applications     Open Access   (Followers: 21)
Advances in Polymer Science     Hybrid Journal   (Followers: 54)
Advances in Porous Media     Full-text available via subscription   (Followers: 6)
Advances in Remote Sensing     Open Access   (Followers: 59)
Advances in Science and Research (ASR)     Open Access   (Followers: 8)
Aerobiologia     Hybrid Journal   (Followers: 4)
Aerospace Systems     Hybrid Journal   (Followers: 10)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 8)
AIChE Journal     Hybrid Journal   (Followers: 38)
Ain Shams Engineering Journal     Open Access   (Followers: 7)
Al-Nahrain Journal for Engineering Sciences     Open Access  
Al-Qadisiya Journal for Engineering Sciences     Open Access   (Followers: 2)
AL-Rafdain Engineering Journal     Open Access   (Followers: 3)
Alexandria Engineering Journal     Open Access   (Followers: 3)
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: 12)
American Journal of Engineering Education     Open Access   (Followers: 20)
American Journal of Environmental Engineering     Open Access   (Followers: 16)
American Journal of Industrial and Business Management     Open Access   (Followers: 31)
Annals of Civil and Environmental Engineering     Open Access   (Followers: 3)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Pure and Applied Logic     Open Access   (Followers: 6)
Annals of Regional Science     Hybrid Journal   (Followers: 10)
Annals of Science     Hybrid Journal   (Followers: 10)
Annual Journal of Technical University of Varna     Open Access   (Followers: 1)
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: 2)
Applications in Energy and Combustion Science     Open Access   (Followers: 4)
Applications in Engineering Science     Open Access   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 8)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 22)
Applied Clay Science     Hybrid Journal   (Followers: 6)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 16)
Applied Engineering Letters     Open Access   (Followers: 5)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 4)
Applied Nanoscience     Open Access   (Followers: 11)
Applied Network Science     Open Access   (Followers: 3)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 6)
Applied Physics Research     Open Access   (Followers: 7)
Applied Sciences     Open Access   (Followers: 6)
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: 6)
Archives of Thermodynamics     Open Access   (Followers: 13)
Arctic     Open Access   (Followers: 7)
Arid Zone Journal of Engineering, Technology and Environment     Open Access   (Followers: 2)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ArtefaCToS : Revista de estudios sobre la ciencia y la tecnología     Open Access   (Followers: 1)
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: 7)
Assembly Automation     Hybrid Journal   (Followers: 2)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
AURUM : Mühendislik Sistemleri ve Mimarlık Dergisi = Aurum Journal of Engineering Systems and Architecture     Open Access   (Followers: 1)
Australasian Journal of Engineering Education     Hybrid Journal   (Followers: 3)
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Hybrid Journal   (Followers: 2)
Autocracy : Jurnal Otomasi, Kendali, dan Aplikasi Industri     Open Access  
Automotive and Engine Technology     Hybrid Journal  
Automotive Experiences     Open Access  
Automotive Innovation     Hybrid Journal   (Followers: 1)
Avances en Ciencias e Ingenierías     Open Access  
Avances: Investigación en Ingeniería     Open Access   (Followers: 6)
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 2)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 6)
Batteries     Open Access   (Followers: 11)
Batteries & Supercaps     Hybrid Journal   (Followers: 7)
Bautechnik     Hybrid Journal   (Followers: 3)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 29)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (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   (Followers: 1)
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 14)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 14)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 6)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 6)
Biomedical Microdevices     Hybrid Journal   (Followers: 9)
Biomedical Science and Engineering     Open Access   (Followers: 8)
Biomicrofluidics     Open Access   (Followers: 7)
Biotechnology Progress     Hybrid Journal   (Followers: 44)
Black Sea Journal of Engineering and Science     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)
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 13)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 15)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers Droit, Sciences & Technologies     Open Access   (Followers: 1)
Calphad     Hybrid Journal   (Followers: 2)
Canadian Geotechnical Journal     Hybrid Journal   (Followers: 30)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 50)
Carpathian Journal of Electronic and Computer Engineering     Open Access  
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 6)
Case Studies in Thermal Engineering     Open Access   (Followers: 8)
Catalysis Communications     Hybrid Journal   (Followers: 7)
Catalysis Letters     Hybrid Journal   (Followers: 3)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 9)
Catalysis Science and Technology     Hybrid Journal   (Followers: 13)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 4)
Catalysis Today     Hybrid Journal   (Followers: 8)
CEAS Space Journal     Hybrid Journal   (Followers: 6)
Cell Reports Physical Science     Open Access  
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 2)
Central European Journal of Engineering     Hybrid Journal  
CFD Letters     Open Access   (Followers: 8)
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 3)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chaos, Solitons & Fractals : X     Open Access   (Followers: 1)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 3)
Chinese Journal of Engineering     Open Access   (Followers: 2)
Chinese Journal of Population, Resources and Environment     Open Access  
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: 2)
CienciaUAT     Open Access   (Followers: 1)
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Hybrid Journal   (Followers: 11)
CIRP Journal of Manufacturing Science and Technology     Hybrid Journal   (Followers: 14)
City, Culture and Society     Hybrid Journal   (Followers: 27)
Clay Minerals     Hybrid Journal   (Followers: 9)
Coal Science and Technology     Full-text available via subscription   (Followers: 4)
Coastal Engineering     Hybrid Journal   (Followers: 14)
Coastal Engineering Journal     Hybrid Journal   (Followers: 9)
Coastal Engineering Proceedings : Proceedings of the International Conference on Coastal Engineering     Open Access   (Followers: 2)
Coastal Management     Hybrid Journal   (Followers: 30)
Coatings     Open Access   (Followers: 4)
Cogent Engineering     Open Access   (Followers: 3)
Cognitive Computation     Hybrid Journal   (Followers: 3)
Color Research & Application     Hybrid Journal   (Followers: 4)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 18)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 21)
Communications Faculty of Sciences University of Ankara Series A2-A3 Physical Sciences and Engineering     Open Access  
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Components, Packaging and Manufacturing Technology, IEEE Transactions on     Hybrid Journal   (Followers: 28)
Composite Interfaces     Hybrid Journal   (Followers: 10)
Composite Structures     Hybrid Journal   (Followers: 335)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 279)
Composites Part B : Engineering     Hybrid Journal   (Followers: 312)
Composites Part C : Open Access     Open Access   (Followers: 3)
Composites Science and Technology     Hybrid Journal   (Followers: 247)
Comptes Rendus : Mécanique     Open Access   (Followers: 2)
Computation     Open Access   (Followers: 1)
Computational Geosciences     Hybrid Journal   (Followers: 20)
Computational Optimization and Applications     Hybrid Journal   (Followers: 11)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
Computer Science and Engineering     Open Access   (Followers: 21)

        1 2 3 4 5 6 7 8 | Last

Similar Journals
Journal Cover
Batteries
Number of Followers: 11  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2313-0105
Published by MDPI Homepage  [238 journals]
  • Batteries, Vol. 7, Pages 64: High-Potential Test for Quality Control of
           Separator Defects in Battery Cell Production

    • Authors: Louisa Hoffmann, Manuel Kasper, Maik Kahn, Georg Gramse, Gabriela Ventura Silva, Christoph Herrmann, Michael Kurrat, Ferry Kienberger
      First page: 64
      Abstract: Lithium-ion batteries are a key technology for electromobility; thus, quality control in cell production is a central aspect for the success of electric vehicles. The detection of defects and poor insulation behavior of the separator is essential for high-quality batteries. Optical quality control methods in cell production are unable to detect small but still relevant defects in the separator layer, e.g., pinholes or particle contaminations. This gap can be closed by executing high-potential testing to analyze the insulation performance of the electrically insulating separator layer in a pouch cell. Here, we present an experimental study to identify different separator defects on dry cell stacks on the basis of electric voltage stress and mechanical pressure. In addition, finite element modeling (FEM) is used to generate physical insights into the partial discharge by examining the defect structures and the corresponding electric fields, including topographical electrode roughness, impurity particles, and voids in the separator. The test results show that hard discharges are associated with significant separator defects. Based on the study, a voltage of 350 to 450 V and a pressure of 0.3 to 0.6 N/mm2 are identified as optimum ranges for the test methodology, resulting in failure detection rates of up to 85%.
      Citation: Batteries
      PubDate: 2021-09-24
      DOI: 10.3390/batteries7040064
      Issue No: Vol. 7, No. 4 (2021)
       
  • Batteries, Vol. 7, Pages 65: Effect of the Etching Profile of a Si
           Substrate on the Capacitive Characteristics of Three-Dimensional
           Solid-State Lithium-Ion Batteries

    • Authors: Sergei Kurbatov, Alexander Mironenko, Victor Naumov, Alexander Skundin, Alexander Rudy
      First page: 65
      Abstract: Along with the soaring demands for all-solid-state thin-film lithium-ion batteries, the problem of their energy density rise becomes very acute. The solution to this problem can be found in development of 3D batteries. The present work deals with the development of a technology for a 3D solid-state lithium-ion battery (3D SSLIB) manufacturing by plasma-chemical etching and magnetron sputtering technique. The results on testing of experimental samples of 3D SSLIB are presented. It was found that submicron-scale steps appearing on the surface of a 3D structure formed on Si substrate by the Bosch process radically change the crystal structure of the upper functional layers. Such changes can lead to disruption of the layers’ continuity, especially that of the down conductors. It is shown that surface polishing by liquid etching of the SiO2 layer and silicon reoxidation leads to surface smoothing, the replacement of the dendrite structure of functional layers by a block structure, and a significant improvement in the capacitive characteristics of the battery.
      Citation: Batteries
      PubDate: 2021-09-28
      DOI: 10.3390/batteries7040065
      Issue No: Vol. 7, No. 4 (2021)
       
  • Batteries, Vol. 7, Pages 66: Attention-Based Long Short-Term Memory
           Recurrent Neural Network for Capacity Degradation of Lithium-Ion Batteries
           

    • Authors: Tadele Mamo, Fu-Kwun Wang
      First page: 66
      Abstract: Monitoring cycle life can provide a prediction of the remaining battery life. To improve the prediction accuracy of lithium-ion battery capacity degradation, we propose a hybrid long short-term memory recurrent neural network model with an attention mechanism. The hyper-parameters of the proposed model are also optimized by a differential evolution algorithm. Using public battery datasets, the proposed model is compared to some published models, and it gives better prediction performance in terms of mean absolute percentage error and root mean square error. In addition, the proposed model can achieve higher prediction accuracy of battery end of life.
      Citation: Batteries
      PubDate: 2021-10-13
      DOI: 10.3390/batteries7040066
      Issue No: Vol. 7, No. 4 (2021)
       
  • Batteries, Vol. 7, Pages 67: Influence of Temperature and Electrolyte
           Composition on the Performance of Lithium Metal Anodes

    • Authors: Sanaz Momeni Boroujeni, Alexander Fill, Alexander Ridder, Kai Peter Birke
      First page: 67
      Abstract: Lithium metal anodes have again attracted widespread attention due to the continuously growing demand of cells with higher energy density. However, the lithium deposition mechanism and the affecting process of influencing factors, such as temperature, cycling current density, and electrolyte composition are not fully understood and require further investigation. In this article, the behavior of lithium metal anode at different temperatures (25, 40, and 60 ∘C), lithium salts, electrolyte concentrations (1 and 2 M), and the applied cell current (equivalent to 0.5 C, 1 C, and 2 C). is investigated. Two different salts were evaluated: lithium bis(fluorosulfonyl)imide (LiFSI) and lithium bis(trifluoromethanesul-fonyl)imide (LiTFSI). The cells at a medium temperature (40 ∘C) show the highest Coulombic efficiency (CE). However, shorter cycle life is observed compared to the experiments at room temperature (25 ∘C). Regardless of electrolyte type and C-rate, the higher temperature of 60 ∘C provides the worst Coulombic efficiency and cycle life among those at the examined temperatures. A higher C-rate has a positive effect on the stability over the cycle life of the lithium cells. The best performance in terms of long cycle life and relatively good Coulombic efficiency is achieved by fast charging the cell with high concentration LiFSI in 1,2-dimethoxyethane (DME) electrolyte at a temperature of 25 ∘C. The cell has an average Coulombic efficiency of 0.987 over 223 cycles. In addition to galvanostatic experiments, Electrochemical Impedance Spectroscopy (EIS) measurements were performed to study the evolution of the interface under different conditions during cycling.
      Citation: Batteries
      PubDate: 2021-10-14
      DOI: 10.3390/batteries7040067
      Issue No: Vol. 7, No. 4 (2021)
       
  • Batteries, Vol. 7, Pages 68: Thermal Runaway Modelling of Li-Ion Cells at
           Various States of Ageing with a Semi-Empirical Model Based on a Kinetic
           Equation

    • Authors: Mathilde Grandjacques, Pierre Kuntz, Philippe Azaïs, Sylvie Genies, Olivier Raccurt
      First page: 68
      Abstract: The thermal runaway model used is a semi-empirical model based on a kinetic equation, parametrised by three parameters (m,n,p). It is believed that this kinetic equation can describe any reaction. The choice of parameters is often made without justifications. We assumed it necessary to develop a method to select the parameters. The method proposed is based on data coming from an accelerating rate calorimeter (ARC) test. The method has been applied on data obtained for cells aged on different conditions. Thanks to a post-mortem analysis and simulations carried out using the parameters obtained, we have shown that the ageing mechanisms have a major impact on the parameters.
      Citation: Batteries
      PubDate: 2021-10-18
      DOI: 10.3390/batteries7040068
      Issue No: Vol. 7, No. 4 (2021)
       
  • Batteries, Vol. 7, Pages 69: High-Performance Amorphous Carbon Coated
           LiNi0.6Mn0.2Co0.2O2 Cathode Material with Improved Capacity Retention for
           Lithium-Ion Batteries

    • Authors: Anish Raj Kathribail, Arlavinda Rezqita, Daniel Lager, Raad Hamid, Yuri Surace, Maitane Berecibar, Joeri Van Mierlo, Annick Hubin, Marcus Jahn, Jürgen Kahr
      First page: 69
      Abstract: Coating conducting polymers onto active cathode materials has been proven to mitigate issues at high current densities stemming from the limited conducting abilities of the metal-oxides. In the present study, a carbon coating was applied onto nickel-rich NMC622 via polymerisation of furfuryl alcohol, followed by calcination, for the first time. The formation of a uniform amorphous carbon layer was observed with scanning- and transmission-electron microscopy (SEM and TEM) and X-ray photoelectron spectroscopy (XPS). The stability of the coated active material was confirmed and the electrochemical behaviour as well as the cycling stability was evaluated. The impact of the heat treatment on the electrochemical performance was studied systematically and was shown to improve cycling and high current performance alike. In-depth investigations of polymer coated samples show that the improved performance can be correlated with the calcination temperatures. In particular, a heat treatment at 400 °C leads to enhanced reversibility and capacity retention even after 400 cycles. At 10C, the discharge capacity for carbon coated NMC increases by nearly 50% compared to uncoated samples. This study clearly shows for the first time the synergetic effects of a furfuryl polymer coating and subsequent calcination leading to improved electrochemical performance of nickel-rich NMC622.
      Citation: Batteries
      PubDate: 2021-10-26
      DOI: 10.3390/batteries7040069
      Issue No: Vol. 7, No. 4 (2021)
       
  • Batteries, Vol. 7, Pages 70: Comprehensive Insights into the Porosity of
           Lithium-Ion Battery Electrodes: A Comparative Study on Positive Electrodes
           Based on LiNi0.6Mn0.2Co0.2O2 (NMC622)

    • Authors: Thomas Beuse, Mathias Fingerle, Christian Wagner, Martin Winter, Markus Börner
      First page: 70
      Abstract: Porosity is frequently specified as only a value to describe the microstructure of a battery electrode. However, porosity is a key parameter for the battery electrode performance and mechanical properties such as adhesion and structural electrode integrity during charge/discharge cycling. This study illustrates the importance of using more than one method to describe the electrode microstructure of LiNi0.6Mn0.2Co0.2O2 (NMC622)-based positive electrodes. A correlative approach, from simple thickness measurements to tomography and segmentation, allowed deciphering the true porous electrode structure and to comprehend the advantages and inaccuracies of each of the analytical techniques. Herein, positive electrodes were calendered from a porosity of 44–18% to cover a wide range of electrode microstructures in state-of-the-art lithium-ion batteries. Especially highly densified electrodes cannot simply be described by a close packing of active and inactive material components, since a considerable amount of active material particles crack due to the intense calendering process. Therefore, a digital 3D model was created based on tomography data and simulation of the inactive material, which allowed the investigation of the complete pore network. For lithium-ion batteries, the results of the mercury intrusion experiments in combination with gas physisorption/pycnometry experiments provide comprehensive insight into the microstructure of positive electrodes.
      Citation: Batteries
      PubDate: 2021-10-26
      DOI: 10.3390/batteries7040070
      Issue No: Vol. 7, No. 4 (2021)
       
  • Batteries, Vol. 7, Pages 42: Thermal Conductivity in Aged Li-Ion Cells
           under Various Compression Conditions and State-of-Charge

    • Authors: Georgi Kovachev, Andrea Astner, Gregor Gstrein, Luigi Aiello, Johann Hemmer, Wolfgang Sinz, Christian Ellersdorfer
      First page: 42
      Abstract: Thermal conductivity (TC) is a parameter, which significantly influences the spatial temperature gradients of lithium ion batteries in operative or abuse conditions. It affects the dissipation of the generated heat by the cell during normal operation or during thermal runaway propagation from one cell to the next after an external short circuit. Hence, the thermal conductivity is a parameter of great importance, which concurs to assess the safety of a Li-ion battery. In this work, an already validated, non-destructive measurement procedure was adopted for the determination of the evolution of the through-plane thermal conductivity of 41 Ah commercially available Li-ion pouch cells (LiNiMnCoO2-LiMn2O4/Graphite) as function of battery lifetime and state of charge (SOC). Results show a negative parabolic behaviour of the thermal conductivity over the battery SOC-range. In addition, an average decrease of TC in thickness direction of around 4% and 23% was measured for cells cycled at 60 °C with and without compression, respectively. It was shown that pretension force during cycling reduces battery degradation and thus minimises the effect of ageing on the thermal parameter deterioration. Nevertheless, this study highlights the need of adjustment of the battery pack cooling system due to the deterioration of thermal conductivity after certain battery lifetime with the aim of reducing the risk of battery overheating after certain product life.
      Citation: Batteries
      PubDate: 2021-06-25
      DOI: 10.3390/batteries7030042
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 43: Correction: Paccha-Herrera et al. Thermal
           Modeling Approaches for a LiCoO2 Lithium-ion Battery—A Comparative Study
           with Experimental Validation. Batteries 2020, 6, 40

    • Authors: Edwin Paccha-Herrera, Williams R. Calderón-Muñoz, Marcos Orchard, Francisco Jaramillo, Kamal Medjaher
      First page: 43
      Abstract: The authors wish to make the following corrections to their paper [...]
      Citation: Batteries
      PubDate: 2021-06-25
      DOI: 10.3390/batteries7030043
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 44: Investigation into the Lithium-Ion Battery
           Fire Resistance Testing Procedure for Commercial Use

    • Authors: Daniel Darnikowski, Magdalena Mieloszyk
      First page: 44
      Abstract: Lithium-ion batteries (LIBs) have many advantages (e.g., high voltage and long-life cycle) in comparison to other energy storage technologies (e.g., lead acid), resulting in their applicability in a wide variety of structures. Simultaneously, the thermal stability of LIBs is relatively poor and can be damaged by exposure to fire. This paper presents an investigation into a fire resistance safety test for LIBs and the use of thermal sensors to evaluate exposure conditions and estimate the temperatures to which cells are subjected. Temperature distribution data and statistical analysis show significant differences of over 200 ∘C, indicating the stochastic nature of the heating curve despite following the testing procedure requirements. We concluded that the current testing procedure is inadequate for the reliable testing of LIBs, leaving an alarming loophole in the fire safety evaluation. The observed instability is mostly related to wind speed and direction, and fire source size.
      Citation: Batteries
      PubDate: 2021-06-30
      DOI: 10.3390/batteries7030044
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 45: An ASIC-Based Miniaturized System for Online
           Multi-Measurand Monitoring of Lithium-Ion Batteries

    • Authors: Giuseppe Manfredini, Andrea Ria, Paolo Bruschi, Luca Gerevini, Michele Vitelli, Mario Molinara, Massimo Piotto
      First page: 45
      Abstract: To better asses the ageing and to reduce the hazards involved in the use of Lithium-Ion Batteries, multi-measurand monitoring units and strategies are urged. In this paper, a Cell Management Unit, based on the SENSIPLUS chip, a recently introduced multichannel, multi-mode sensor interface, is described. SENSIPLUS is a single System on a Chip combined with a reduced number of external components, resulting in a highly miniaturized device, built on 20 × 8 mm2 printed circuit board. Thanks to SENSIPLUS’ versatility, the proposed system is capable of performing direct measurements (EIS, cell voltage) on the cell it is applied to, and reading different kinds of sensors. The SENSIPLUS versatile digital communication interface, combined with a digital isolator, enable connection of several devices to a single bus for parallel monitoring a large number of cells connected in series. Experiments performed by connecting the proposed system to a commercial Lithium-Ion Battery and to capacitive and resistive sensors are described. In particular, the capability of measuring the cell internal impedance with a resolution of 120 μΩ is demonstrated.
      Citation: Batteries
      PubDate: 2021-07-05
      DOI: 10.3390/batteries7030045
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 46: Detection of Lithium Plating in Li-Ion Cell
           Anodes Using Realistic Automotive Fast-Charge Profiles

    • Authors: Matteo Dotoli, Emanuele Milo, Mattia Giuliano, Riccardo Rocca, Carlo Nervi, Marcello Baricco, Massimiliano Ercole, Mauro Francesco Sgroi
      First page: 46
      Abstract: The widespread use of electric vehicles is nowadays limited by the “range anxiety” of the customers. The drivers’ main concerns are related to the kilometric range of the vehicle and to the charging time. An optimized fast-charge profile can help to decrease the charging time, without degrading the cell performance and reducing the cycle life. One of the main reasons for battery capacity fade is linked to the Lithium plating phenomenon. This work investigates two methodologies, i.e., three-electrode cell measurement and internal resistance evolution during charging, for detecting the Lithium plating conditions. From this preliminary analysis, it was possible to develop new Multi-Stage Constant-Current profiles, designed to improve the performance in terms of charging time and cells capacity retention with respect to a reference profile. Four new profiles were tested and compared to a reference. The results coming from the new profiles demonstrate a simultaneous improvement in terms of charging time and cycling life, showing the reliability of the implemented methodology in preventing Lithium plating.
      Citation: Batteries
      PubDate: 2021-07-07
      DOI: 10.3390/batteries7030046
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 47: Versatile AC Current Control Technique for a
           Battery Using Power Converters

    • Authors: S. M. Rakiul Islam, Sung-Yeul Park
      First page: 47
      Abstract: Although a battery is a DC device, AC current is often necessary for testing, preheating, impedance spectroscopy, and advanced charging. This paper presents a versatile control technique to inject AC current to a battery. Synchronous buck and H-bridge topologies are operated in bidirectional mode and controlled by uni-polar and bi-polar pulse width modulation techniques for the AC current injection. The input and output passive circuits are specially designed considering AC current and the properties of the battery. A controller is proposed considering a small internal impedance, small AC ripple voltage, and variable DC offset voltage of a battery. The controller is capable of maintaining stable operation of AC current injection in two power quadrant within a small DC voltage boundary of a battery. The controller is comprised of a feedback compensator, a feedforward term, and an estimator. The feedback gain is designed considering the internal impedance. The feedforward gain is designed based on estimated open circuit battery voltage and input voltage. The open circuit voltage estimator is designed based on filters and battery model. For validation, AC current is injected to a Valence U-12XP battery. The battery is rated for 40 Ah nominal capacity and 13.8 V nominal voltage The controller successfully injected AC current to a battery with +10 A, 0 A and −10 A DC currents. The magnitude and frequency of the AC current was up to 5 A and 2 kHz respectively.
      Citation: Batteries
      PubDate: 2021-07-15
      DOI: 10.3390/batteries7030047
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 48: Identification of Degradation Mechanisms by
           Post-Mortem Analysis for High Power and High Energy Commercial Li-Ion
           Cells after Electric Vehicle Aging

    • Authors: Kuntz, Raccurt, Azaïs, Richter, Waldmann, Wohlfahrt-Mehrens, Bardet, Buzlukov, Genies
      First page: 48
      Abstract: Driven by the rise of the electric automotive industry, the Li-ion battery market is in strong expansion. This technology does not only fulfill the requirements of electric mobility, but is also found in most portable electric devices. Even though Li-ion batteries are known for their numerous advantages, they undergo serious performance degradation during their aging, and more particularly when used in specific conditions such as at low temperature or high charging current rates. Depending on the operational conditions, different aging mechanisms are favored and can induce physical and chemical modifications of the internal components, leading to performance decay. In this article, the identification of the degradation mechanisms was carried out thanks to an in-depth ante- and post mortem study on three high power and high energy commercial 18,650 cells. Li-ion cells were aged using a battery electric vehicle (BEV) aging profile at −20 °C, 0 °C, 25 °C, and 45 °C in accordance with the international standard IEC 62-660, and in calendar aging mode at 45 °C and SOC 100%. Internal components recovered from fresh and aged cells were investigated through different electrochemical (half-coin cell), chemical (EDX, GD-OES, NMR), and topological (SEM) characterization techniques. The influence of power and energy cells’ internal design and Si content in the negative electrode on cell aging has been highlighted vis-à-vis the capacity and power fade.
      Citation: Batteries
      PubDate: 2021-07-16
      DOI: 10.3390/batteries7030048
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 49: Analysis and Investigation of Thermal Runaway
           Propagation for a Mechanically Constrained Lithium-Ion Pouch Cell Module

    • Authors: Luigi Aiello, Ilie Hanzu, Gregor Gstrein, Eduard Ewert, Christian Ellersdorfer, Wolfgang Sinz
      First page: 49
      Abstract: In this paper, tests and analysis of thermal runaway propagation for commercial modules consisting of four 41 Ah Li-ion pouch cells are presented. Module samples were tested at 100% state-of-charge and mechanically constrained between two steel plates to provide thermal and mechanical contact between the parts. Voltage and temperature of each cell were monitored during the whole experiment. The triggering of the exothermal reactions was obtained by overheating one cell of the stack with a flat steel heater. In preliminary studies, the melting temperature of the separator was measured (from an extracted sample) with differential scanning calorimetry and thermogravimetric analysis techniques, revealing a tri-layers separator with two melting points (≈135 °C and ≈170 °C). The tests on module level revealed 8 distinct phases observed and analyzed in the respective temperature ranges, including smoking, venting, sparkling, and massive, short circuit condition. The triggering temperature of the cells resulted to be close to the melting temperature of the separator obtained in preliminary tests, confirming that the violent exothermal reactions of thermal runaway are caused by the internal separator failure. Postmortem inspections of the modules revealed the internal electrical failure path in one cell and the propagation of the internal short circuit in its active material volume, suggesting that the expansion of the electrolyte plays a role in the short circuit propagation at the single cell level. The complete thermal runaway propagation process was repeated on 5 modules and ended on average 60 s after the first thermal runaway triggered cell reached a top temperature of 1100 °C.
      Citation: Batteries
      PubDate: 2021-07-19
      DOI: 10.3390/batteries7030049
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 50: Biopolimer Peptide Batteries—A New Concept
           for Environmentally Friendly and Safer Energy Storage

    • Authors: Volodymyr Moklyak, Andrii Hrubiak, Zurab Gogitidze, Yurii Yavorskyi
      First page: 50
      Abstract: The work shows a new approach to improving the performance of lithium power sources by using polypeptides as an active component of the cathode composition. Specifically, the experimental results of testing prototypes of lithium current sources with cathodes based on polypeptides, which demonstrate the value of the specific discharge capacity at the level of 2000–2700 mAh/g, depending on the content of the organic component, are presented. The use of the intermittent galvanostatic titration mode during the discharge showed an increase in the specific indicators of the current sources in comparison with the continuous discharge at different specific load currents. Based on this, the effect of “relaxation recovery” of the cathode material based on polypeptides was discovered, the essence of which is a significant increase (recovery) of the open-circuit voltage when the load of the lithium current source is disconnected, which leads to an increase of the discharge capacity without external energy influences. The functionalization of the surface of thermally expanded graphite with polypeptide components made it possible to create a cathode material, the use of which in lithium current source models increased the specific discharge capacity to 19,000 mA h/g at a discharge current of 10 mA/h.
      Citation: Batteries
      PubDate: 2021-07-20
      DOI: 10.3390/batteries7030050
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 51: Comparative Study of Equivalent Circuit
           Models Performance in Four Common Lithium-Ion Batteries: LFP, NMC, LMO,
           NCA

    • Authors: Manh-Kien Tran, Andre DaCosta, Anosh Mevawalla, Satyam Panchal, Michael Fowler
      First page: 51
      Abstract: Lithium-ion (Li-ion) batteries are an important component of energy storage systems used in various applications such as electric vehicles and portable electronics. There are many chemistries of Li-ion battery, but LFP, NMC, LMO, and NCA are four commonly used types. In order for the battery applications to operate safely and effectively, battery modeling is very important. The equivalent circuit model (ECM) is a battery model often used in the battery management system (BMS) to monitor and control Li-ion batteries. In this study, experiments were performed to investigate the performance of three different ECMs (1RC, 2RC, and 1RC with hysteresis) on four Li-ion battery chemistries (LFP, NMC, LMO, and NCA). The results indicated that all three models are usable for the four types of Li-ion chemistries, with low errors. It was also found that the ECMs tend to perform better in dynamic current profiles compared to non-dynamic ones. Overall, the best-performed model for LFP and NCA was the 1RC with hysteresis ECM, while the most suited model for NMC and LMO was the 1RC ECM. The results from this study showed that different ECMs would be suited for different Li-ion battery chemistries, which should be an important factor to be considered in real-world battery and BMS applications.
      Citation: Batteries
      PubDate: 2021-07-27
      DOI: 10.3390/batteries7030051
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 52: Combining the Distribution of Relaxation
           Times from EIS and Time-Domain Data for Parameterizing Equivalent Circuit
           Models of Lithium-Ion Batteries

    • Authors: Leo Wildfeuer, Philipp Gieler, Alexander Karger
      First page: 52
      Abstract: Equivalent circuit models (ECMs) are a widely used modeling approach for lithium-ion batteries in engineering applications. The RC elements, which display the dynamic loss processes of the cell, are usually parameterized by fitting the ECM to experimental data in either the time-domain or the frequency-domain. However, both types of data have limitations with regard to the observable time constants of electrochemical processes. This work proposes a method to combine time-domain and frequency-domain measurement data for parameterization of RC elements by exploiting the full potential of the distribution of relaxation times (DRT). Instead of using only partial information from the DRT to supplement a conventional fitting algorithm, we determine the parameters of an arbitrary number of RC elements directly from the DRT. The difficulties of automated deconvolution of the DRT, including regularization and the choice of an optimal regularization factor, is tackled by using the L-curve criterion for optimized calculation of the DRT via Tikhonov regularization. Three different approaches to merge time- and frequency-domain data are presented, including a novel approach where the DRT is simultaneously calculated from electrochemical impedance spectoscropy (EIS) and pulse relaxation measurements. The parameterized model for a commercial 18650 NCA cell was validated during a validation cycle consisting of constant current and real-world automotive cycling and yields a relative improvement of over 40% compared to a conventional EIS-fitting algorithm.
      Citation: Batteries
      PubDate: 2021-08-02
      DOI: 10.3390/batteries7030052
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 53: In-Situ Tools Used in Vanadium Redox Flow
           Battery Research—Review

    • Authors: Purna C. Ghimire, Arjun Bhattarai, Tuti M. Lim, Nyunt Wai, Maria Skyllas-Kazacos, Qingyu Yan
      First page: 53
      Abstract: Progress in renewable energy production has directed interest in advanced developments of energy storage systems. The all-vanadium redox flow battery (VRFB) is one of the attractive technologies for large scale energy storage due to its design versatility and scalability, longevity, good round-trip efficiencies, stable capacity and safety. Despite these advantages, the deployment of the vanadium battery has been limited due to vanadium and cell material costs, as well as supply issues. Improving stack power density can lower the cost per kW power output and therefore, intensive research and development is currently ongoing to improve cell performance by increasing electrode activity, reducing cell resistance, improving membrane selectivity and ionic conductivity, etc. In order to evaluate the cell performance arising from this intensive R&D, numerous physical, electrochemical and chemical techniques are employed, which are mostly carried out ex situ, particularly on cell characterizations. However, this approach is unable to provide in-depth insights into the changes within the cell during operation. Therefore, in situ diagnostic tools have been developed to acquire information relating to the design, operating parameters and cell materials during VRFB operation. This paper reviews in situ diagnostic tools used to realize an in-depth insight into the VRFBs. A systematic review of the previous research in the field is presented with the advantages and limitations of each technique being discussed, along with the recommendations to guide researchers to identify the most appropriate technique for specific investigations.
      Citation: Batteries
      PubDate: 2021-08-04
      DOI: 10.3390/batteries7030053
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 54: Layered Iron Vanadate as a High-Capacity
           Cathode Material for Nonaqueous Calcium-Ion Batteries

    • Authors: Munseok S. Chae, Dedy Setiawan, Hyojeong J. Kim, Seung-Tae Hong
      First page: 54
      Abstract: Calcium-ion batteries represent a promising alternative to the current lithium-ion batteries. Nevertheless, calcium-ion intercalating materials in nonaqueous electrolytes are scarce, probably due to the difficulties in finding suitable host materials. Considering that research into calcium-ion batteries is in its infancy, discovering and characterizing new host materials would be critical to further development. Here, we demonstrate FeV3O9∙1.2H2O as a high-performance calcium-ion battery cathode material that delivers a reversible discharge capacity of 303 mAh g−1 with a good cycling stability and an average discharge voltage of ~2.6 V (vs. Ca/Ca2+). The material was synthesized via a facile co-precipitation method. Its reversible capacity is the highest among calcium-ion battery materials, and it is the first example of a material with a capacity much larger than that of conventional lithium-ion battery cathode materials. Bulk intercalation of calcium into the host lattice contributed predominantly to the total capacity at a lower rate, but became comparable to that due to surface adsorption at a higher rate. This stimulating discovery will lead to the development of new strategies for obtaining high energy density calcium-ion batteries.
      Citation: Batteries
      PubDate: 2021-08-09
      DOI: 10.3390/batteries7030054
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 55: Carbon Monoliths with Hierarchical Porous
           Structure for All-Vanadium Redox Flow Batteries

    • Authors: Jose Francisco Vivo-Vilches, Blagoj Karakashov, Alain Celzard, Vanessa Fierro, Ranine El Hage, Nicolas Brosse, Anthony Dufour, Mathieu Etienne
      First page: 55
      Abstract: Carbon monoliths were tested as electrodes for vanadium redox batteries. The materials were synthesised by a hard-templating route, employing sucrose as carbon precursor and sodium chloride crystals as the hard template. For the preparation process, both sucrose and sodium chloride were ball-milled together and molten into a paste which was hot-pressed to achieve polycondensation of sucrose into a hard monolith. The resultant material was pyrolysed in nitrogen at 750 °C, and then washed to remove the salt by dissolving it in water. Once the porosity was opened, a second pyrolysis step at 900 °C was performed for the complete conversion of the materials into carbon. The products were next characterised in terms of textural properties and composition. Changes in porosity, obtained by varying the proportions of sucrose to sodium chloride in the initial mixture, were correlated with the electrochemical performances of the samples, and a good agreement between capacitive response and microporosity was indeed observed highlighted by an increase in the cyclic voltammetry curve area when the SBET increased. In contrast, the reversibility of vanadium redox reactions measured as a function of the difference between reduction and oxidation potentials was correlated with the accessibility of the active vanadium species to the carbon surface, i.e., was correlated with the macroporosity. The latter was a critical parameter for understanding the differences of energy and voltage efficiencies among the materials, those with larger macropore volumes having the higher efficiencies.
      Citation: Batteries
      PubDate: 2021-08-10
      DOI: 10.3390/batteries7030055
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 56: Analysis of Electrochemical Impedance
           Spectroscopy on Zinc-Air Batteries Using the Distribution of Relaxation
           Times

    • Authors: Robert Franke-Lang, Julia Kowal
      First page: 56
      Abstract: Zinc-air batteries could be a key technology for higher energy densities of electrochemical energy storage systems. Many questions remain unanswered, however, and new methods for analyses and quantifications are needed. In this study, the distribution of relaxation times (DRT) based on ridge regression was applied to the impedance data of primary zinc-air batteries in a temperature range of 253 K and 313 K and at different State-of-Charges for the first time. Furthermore, the problem of the regularization parameter on real impedance spectroscopic measurements was addressed and a method was presented using the reconstruction of impedance data from the DRT as a quality criterion. The DRT was able to identify a so far undiscussed process and thus explain why some equivalent circuit models may fail.
      Citation: Batteries
      PubDate: 2021-08-18
      DOI: 10.3390/batteries7030056
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 57: Life Cycle Modelling of Extraction and
           Processing of Battery Minerals—A Parametric Approach

    • Authors: Nelson Bunyui Manjong, Lorenzo Usai, Odne Stokke Burheim, Anders Hammer Strømman
      First page: 57
      Abstract: Sustainable battery production with low environmental footprints requires a systematic assessment of the entire value chain, from raw material extraction and processing to battery production and recycling. In order to explore and understand the variations observed in the reported footprints of raw battery materials, it is vital to re-assess the footprints of these material value chains. Identifying the causes of these variations by combining engineering and environmental system analysis expands our knowledge of the footprints of these battery materials. This article disaggregates the value chains of six raw battery materials (aluminum, copper, graphite, lithium carbonate, manganese, and nickel) and identifies the sources of variabilities (levers) for each process along each value chain. We developed a parametric attributional process-based life cycle model to explore the effect of these levers on the greenhouse gas (GHG) emissions of the value chains, expressed in kg of CO2e. The parametric life cycle inventory model is used to conduct distinct life cycle assessments (LCA) for each material value chain by varying the identified levers within defined engineering ranges. 570 distinct LCAs are conducted for the aluminum value chain, 450 for copper, 170 for graphite, 39 for lithium carbonate via spodumene, 20 for lithium carbonate via brine, 260 for manganese, and 440 for nickel. Three-dimensional representations of these results for each value chain in kg of CO2e are presented as contour plots with gradient lines illustrating the intensity of lever combinations on the GHG emissions. The results of this study convey multidimensional insights into how changes in the lever settings of value chains yield variations in the overall GHG emissions of the raw materials. Parameterization of these value chains forms a flexible and high-resolution backbone, leading towards a more reliable life cycle assessment of lithium-ion batteries (LIB).
      Citation: Batteries
      PubDate: 2021-08-24
      DOI: 10.3390/batteries7030057
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 58: Thermal Analysis of LMO/Graphite Batteries
           Using Equivalent Circuit Models

    • Authors: Nadjiba Mahfoudi, M’hamed Boutaous, Shihe Xin, Serge Buathier
      First page: 58
      Abstract: An efficient thermal management system (TMS) of electric vehicles requires a high-fidelity battery model. The model should be able to predict the electro-thermal behavior of the battery, considering the operating conditions throughout the battery’s lifespan. In addition, the model should be easy to handle for the online monitoring and control of the TMS. Equivalent circuit models (ECMs) are widely used because of their simplicity and suitable performance. In this paper, the electro-thermal behavior of a prismatic 50 Ah LMO/Graphite cell is investigated. A dynamic model is adopted to describe the battery voltage, current, and heat generation. The battery model parameters are identified for a single cell, considering their evolution versus the state of charge and temperature. The needed experimental data are issued from the measurements carried out, thanks to a special custom electrical bench able to impose a predefined current evolution or driving cycles, controllable by serial interface. The proposed battery parameters, functions of state of charge (SOC), and temperature (T) constitute a set of interesting and complete data, not available in the literature, and suitable for further investigations. The thermal behavior and the dynamic models are validated using the New European Driving Cycle (NEDC), with a large operating time, higher than 3 h. The measurement and model prediction exhibit a temperature difference less than 1.2 °C and a voltage deviation less than 3%, showing that the proposed model accurately predicts current, voltage, and temperature. The combined effects of temperature and SOC provides a more efficient modeling of the cell behavior. Nevertheless, the simplified model with only temperature dependency remains acceptable. Hence, the present modeling constitutes a confident prediction and a real step for an online control of the complete thermal management of electrical vehicles.
      Citation: Batteries
      PubDate: 2021-08-27
      DOI: 10.3390/batteries7030058
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 59: Grid-Scale Battery Energy Storage for
           Arbitrage Purposes: A Colombian Case

    • Authors: Andrés F. Peñaranda, David Romero-Quete, Camilo A. Cortés
      First page: 59
      Abstract: This study seeks to determine a suitable arbitrage strategy that allows a battery energy storage system (BESS) owner to obtain the maximum economic benefits when participating in the Colombian electricity market. A comparison of different arbitration strategies from the literature, such as seasonal, statistical, and neural networks-based models, is performed. To determine BESS’s optimal operation, a Mixed Integer Linear Programming (MILP) optimization problem is formulated, including a battery degradation model based on an upper piecewise linear approximation method. A financial evaluation of the different arbitrage strategies is carried out, resulting, for all the analyzed cases, in a negative net present value (NPV); thus, the results show that the income obtained from BESS when only performing energy arbitrage in the Colombian market do not compensate the investment costs. Results have also shown that strategies based on statistical and prediction models have a better performance than seasonal strategies, especially in atypical circumstances such as COVID-19.
      Citation: Batteries
      PubDate: 2021-09-03
      DOI: 10.3390/batteries7030059
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 60: Review of Achieved Purities after Li-ion
           Batteries Hydrometallurgical Treatment and Impurities Effects on the
           Cathode Performance

    • Authors: Olimpia A. Nasser, Martina Petranikova
      First page: 60
      Abstract: This paper is a product purity study of recycled Li-ion batteries with a focus on hydrometallurgical recycling processes. Firstly, a brief description of the current recycling status was presented based on the research data. Moreover, this work presented the influence of impurities such as Cu, Fe and Mg on recovered cathode materials performance. The impact of the impurities was described depending on their form (metallic or ionic) and concentration. This work also reviewed hydrometallurgical recycling processes depending on the recovered material, obtained purity and recovery methods. This purity data were obtained from both research and battery industry actors. Finally, the purity study was completed by collecting data regarding commercial battery-grade chemical compounds and active lithium cathode materials, including required purity levels and allowed impurity limitations.
      Citation: Batteries
      PubDate: 2021-09-03
      DOI: 10.3390/batteries7030060
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 61: Non-Uniform Circumferential Expansion of
           Cylindrical Li-Ion Cells—The Potato Effect

    • Authors: Jessica Hemmerling, Jajnabalkya Guhathakurta, Falk Dettinger, Alexander Fill, Kai Peter Birke
      First page: 61
      Abstract: This paper presents the non-uniform change in cell thickness of cylindrical Lithium (Li)-ion cells due to the change of State of Charge (SoC). Using optical measurement methods, with the aid of a laser light band micrometer, the expansion and contraction are determined over a complete charge and discharge cycle. The cell is rotated around its own axis by an angle of α=10° in each step, so that the different positions can be compared with each other over the circumference. The experimental data show that, contrary to the assumption based on the physical properties of electrode growth due to lithium intercalation in the graphite, the cell does not expand uniformly. Depending on the position and orientation of the cell coil, there are different zones of expansion and contraction. In order to confirm the non-uniform expansion around the circumference of the cell in 3D, X-ray computed tomography (CT) scans of the cells are performed at low and at high SoC. Comparison of the high resolution 3D reconstructed volumes clearly visualizes a sinusoidal pattern for non-uniform expansion. From the 3D volume, it can be confirmed that the thickness variation does not vary significantly over the height of the battery cell due to the observed mechanisms. However, a slight decrease in the volume change towards the poles of the battery cells due to the higher stiffness can be monitored.
      Citation: Batteries
      PubDate: 2021-09-06
      DOI: 10.3390/batteries7030061
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 62: Power and Energy Rating Considerations in
           Integration of Flow Battery with Solar PV and Residential Load

    • Authors: Purnima Parmeshwarappa, Ravendra Gundlapalli, Sreenivas Jayanti
      First page: 62
      Abstract: Integration of renewable energy sources such as solar photovoltaic (PV) generation with variable power demand systems like residential electricity consumption requires the use of a high efficiency electrical energy system such as a battery. In the present study, such integration has been studied using vanadium redox flow battery (VRFB) as the energy storage system with specific focus on the sizing of the power and energy storage capacities of the system components. Experiments have been carried out with a seven-day simulated solar insolation and residential load characteristics using a 1 kW VRFB stack and variable amounts of electrolyte volume. Several scenarios have been simulated using power and energy scale factors. Battery response, in terms of its power, state of charge and efficiency, has been monitored in each run. Results show that the stack power rating should be based on peak charging characteristics while the volume of electrolyte should be based on the expected daily energy discharge through the battery. The PV source itself should be sized at about 25% more energy rating than the average daily load. The ability to design a VRFB with a high power-to-energy ratio makes it particularly attractive for PV-load integration.
      Citation: Batteries
      PubDate: 2021-09-08
      DOI: 10.3390/batteries7030062
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 63: Battery Crush Test Procedures in Standards
           and Regulation: Need for Augmentation and Harmonisation

    • Authors: Bhavya Kotak, Yash Kotak, Katja Brade, Tibor Kubjatko, Hans-Georg Schweiger
      First page: 63
      Abstract: Battery safety is a prominent concern for the deployment of electric vehicles (EVs). The battery powering an EV contains highly energetic active materials and flammable organic electrolytes. Usually, an EV battery catches fire due to its thermal runaway, either immediately at the time of the accident or can take a while to gain enough heat to ignite the battery chemicals. There are numerous battery abuse testing standards and regulations available globally. Therefore, battery manufacturers are always in dilemma to choose the safest one. Henceforth, to find the optimal outcome of these two major issues, six standards (SAE J2464:2009, GB/T 31485-2015:2015, FreedomCAR:2006, ISO 12405-3:2014, IEC 62660-2:2010, and SAND2017-6295:2017) and two regulations (UN/ECE-R100.02:2013 and GTR 20:2018), that are followed by more than fifty countries in the world, are investigated in terms of their abuse battery testing conditions (crush test). This research proves that there is a need for (a) augmenting these standards and regulations as they do not consider real-life vehicle crash scenarios, and (b) one harmonised framework should be developed, which can be adopted worldwide. These outcomes will solve the battery manufacturers dilemma and will also increase the safety of EV consumers.
      Citation: Batteries
      PubDate: 2021-09-16
      DOI: 10.3390/batteries7030063
      Issue No: Vol. 7, No. 3 (2021)
       
  • Batteries, Vol. 7, Pages 21: Determination of Diffusion Coefficients of
           Lithium in Solid Electrolyte LiPON

    • Authors: Alexander Rudy, Alexander Mironenko, Victor Naumov, Alena Novozhilova, Alexander Skundin, Ivan Fedorov
      First page: 21
      Abstract: A structural model of LiPON solid electrolyte, containing elements that simulate drift conductivity, diffusion conductivity, and leakage current was proposed. The dependence of the impedance of the structural model on frequency was calculated, and the parameters of the model at which the theoretical curve best approximates the experimental Nyquist diagrams were determined. Based on these data, the ion diffusion coefficient and conductivity of LiPON were calculated, which are D1 = 1.5 × 10−11 cm2/s and σ = 1.9 × 10−6 S/cm, respectively.
      Citation: Batteries
      PubDate: 2021-03-29
      DOI: 10.3390/batteries7020021
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 22: Float Current Analysis for Fast Calendar
           Aging Assessment of 18650 Li(NiCoAl)O2/Graphite Cells

    • Authors: Michael Theiler, Christian Endisch, Meinert Lewerenz
      First page: 22
      Abstract: Float currents are steady-state self-discharge currents after a transient phase—caused by anode overhang, polarization, etc.—is accomplished. The float current is measured in this study with a standard test bench for five 18650 cells (Samsung 25R) at potentiostatic conditions while the temperature is changed in 5 K steps from 5 °C to 60 °C. The entire test is performed in about 100 days resulting in 12 measurement points per cell potential for an Arrhenius representation. The float current follows the Arrhenius law with an activation energy of about 60 kJ/mol. The capacity loss measured at reference condition shows a high correlation to the results of float currents analysis. In contrast to classical calendar aging tests, the performed float current analysis enables determining the aging rate with high precision down to at least 10 °C. Returning from higher temperatures to 30 °C reference temperature shows reducing float currents at 30 °C for increasing temperature steps that may originate from an hysteresis effect that has to be investigated in future publications.
      Citation: Batteries
      PubDate: 2021-04-01
      DOI: 10.3390/batteries7020022
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 23: Influence of Aging on the Failing Behavior of
           Automotive Lithium-Ion Batteries

    • Authors: Christiane Essl, Andrey W. Golubkov, Anton Fuchs
      First page: 23
      Abstract: Lithium-ion batteries (LIBs) are a dominant state-of-the-art energy storage system and have importance in the automotive sector. Still, LIBs suffer from aging effects and serious hazards from failing batteries are possible. These failures can lead to exothermic chemical reactions inside the cell, ending up in thermal runaway (TR). TR has caused most electric vehicle (EV) fires. Since statistically most accidents with EVs happen after about one year of vehicle usage, in particular, the failing behavior of aged cells needs to be investigated. Little information is available in open literature about the influence of aging paths on the failing behavior and especially on the degassing behavior of large automotive LIBs. Therefore, this study investigates the influence of three different aging paths (cyclic at −10 °C and at 45 °C and calendric at 60 °C) on the thermal behavior, the vent gas emission, and the vent gas composition. The results show a clear effect of aging on the failing behavior. The aged cells showed a less violent failing reaction, reduced maximal temperatures, lower amount of produced gas, significantly lower amount of CO in the vent gas, and lower mass loss than fresh cells in the same overtemperature experiments. The results are valuable for the scientific and industrial community dealing with LIBs.
      Citation: Batteries
      PubDate: 2021-04-07
      DOI: 10.3390/batteries7020023
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 24: Influence of Multivector Field on Paste
           Preparation and Formation of Negative Electrodes of Lead Batteries

    • Authors: Boris Shirov, Vesselin Naidenov, Urii Markov
      First page: 24
      Abstract: During the operation of the negative electrode, some critical processes take place, which are limiting factors for the operation of lead–acid batteries. To improve the efficiency of the negative active material and minimize these processes, external application of multivector field is proposed. Two applications of the multivector field are studied: during negative paste preparation and during formation. It is established that, when applying multivector field during negative paste preparation, the chemical processes proceed more efficiently. The results are better phase composition and crystallinity of the cured paste, thus increasing the capacity of the consequently built lead batteries by 12% on average. The application of a multivector field during the formation of negative active materials in lead batteries has a positive effect on the skeletal structure, the size and shape of the Pb crystals. This ensures longer service life, which is confirmed by the 17.5% Depth of Discharge continuous tests on 12 V/75 Ah batteries. The batteries formed under the influence of external multivector field showed 20% longer cycle life. Based on the experimental result, a most probable mechanism of the influence of the multivector field on the chemical and electrochemical processes in lead batteries during negative paste preparation and formation of negative active masses is proposed.
      Citation: Batteries
      PubDate: 2021-04-09
      DOI: 10.3390/batteries7020024
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 25: Early Detection of Failing Automotive
           Batteries Using Gas Sensors

    • Authors: Christiane Essl, Lauritz Seifert, Michael Rabe, Anton Fuchs
      First page: 25
      Abstract: Safety for automotive lithium-ion battery (LIB) applications is of crucial importance, especially for electric vehicle applications using batteries with high capacity and high energy density. In case of a defect inside or outside the cell, serious safety risks are possible including extensive heat generation, toxic and flammable gas generation, and consequently fire and explosion. New regulations (GB 38031-2020) require a warning for passengers at least five minutes before serious incidents. This regulation can hardly be fulfilled with state-of-the-art battery monitoring. In this study, gases produced during battery failure before and during a thermal runaway (TR) are investigated in detail and the use of different gas sensors as early detectors of battery incidents is tested and proposed. The response of several commercially available gas sensors is tested in four battery failure cases: unwanted electrolysis of voltage carrying parts, electrolyte vapor, first venting of the cell and the TR. The experiments show that battery failure detection with gas sensors is possible but depends highly on the failure case. The chosen gas sensor can detect H2 produced by unwanted electrolysis and electrolyte vapor and gases produced by degassing of state-of-the-art LIBs. The results may contribute significantly to failure detection and improvement of battery safety.
      Citation: Batteries
      PubDate: 2021-04-12
      DOI: 10.3390/batteries7020025
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 26: High-Performance Lithium Sulfur Batteries
           Based on Multidimensional Graphene-CNT-Nanosulfur Hybrid Cathodes

    • Authors: Álvaro Doñoro, Álvaro Muñoz-Mauricio, Vinodkumar Etacheri
      First page: 26
      Abstract: Although lithium-sulfur (Li-S) batteries are one of the promising candidates for next-generation energy storage, their practical implementation is limited by rapid capacity fading due to lithium polysulfide (LiPSs) formation and the low electronic conductivity of sulfur. Herein, we report a high-performance lithium-sulfur battery based on multidimensional cathode architecture consisting of nanosulfur, graphene nanoplatelets (2D) and multiwalled carbon nanotubes (1D). The ultrasonic synthesis method results in the generation of sulfur nanoparticles and their intercalation into the multilayered graphene nanoplatelets. The optimized multidimensional graphene-sulfur-CNT hybrid cathode (GNS58-CNT10) demonstrated a high specific capacity (1067 mAh g−1 @ 50 mA g−1), rate performance (539 @ 1 A g−1), coulombic efficiency (~95%) and cycling stability (726 mAh g−1 after 100 cycles @ 200 mA g−1) compared to the reference cathode. Superior electrochemical performances are credited to the encapsulation of nanosulfur between the individual layers of graphene nanoplatelets with high electronic conductivity, and effective polysulfide trapping by MWCNT bundles.
      Citation: Batteries
      PubDate: 2021-04-19
      DOI: 10.3390/batteries7020026
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 27: Experimental and Numerical Investigation of
           the Thermal Performance of a Hybrid Battery Thermal Management System for
           an Electric Van

    • Authors: Franck Pra, Jad Al Koussa, Sebastian Ludwig, Carlo M. De Servi
      First page: 27
      Abstract: The temperature and the temperature gradient within the battery pack of an electric vehicle have a strong effect on the life time of the battery cells. In the case of automotive applications, a battery thermal management (BTM) system is required to maintain the temperature of the cells within a prescribed and safe range, and to prevent excessively high thermal gradients within the battery pack. This work documents the assessment of a thermal management system for a battery pack for an electric van, which adopts a combination of active/passive solutions: the battery cells are arranged in a matrix or composite made of expanded graphite and a phase change material (PCM), which can be actively cooled by forced air convection. The thermal dissipation of the cells was predicted based on an equivalent circuit model of the cells (LG Chem MJ1) that was empirically calibrated in a previous study. It resulted that, in order to keep the temperature of the battery pack at or below 40 °C during certain charge/discharge cycles, a purely passive BTM would require a considerable amount of PCM material that would unacceptably increase the battery pack weight. Therefore, the passive solution was combined with an air cooling system that could be activated when necessary. To assess the resulting hybrid BTM concept, CFD simulations were performed and an experimental test setup was built to validate the simulations. In particular, PCM melting and solidification times, the thermal discrepancy among the cells and the melting/solidification temperatures were examined. The melting time experimentally observed was higher than that predicted by the CFD model, but this discrepancy was not observed during the solidification of the PCM. This deviation between the CFD model results and the experimental data during PCM melting can be attributed to the thermal losses occurring through the mock-up casing as the heating elements are in direct contact with the external walls of the casing. Moreover, the temperature range over which the PCM solidifies was 6 °C lower than that estimated in the numerical simulations. This occurs because the simple thermodynamic model cannot predict the metastable state of the liquid phase which occurs before the onset of PCM solidification. The mockup was also used to emulate the heat dissipation of the cells during a highway driving cycle of the eVan and the thermal management solution as designed. Results showed that for this mission of the vehicle and starting from an initial temperature of the cells of 40 °C, the battery pack temperature could be maintained below 40 °C over the entire mission by a cooling air flow at 2.5 m/s and at a temperature of 30 °C.
      Citation: Batteries
      PubDate: 2021-04-28
      DOI: 10.3390/batteries7020027
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 28: Calendar Aging of Li-Ion Cells—Experimental
           Investigation and Empirical Correlation

    • Authors: Daniel Werner, Sabine Paarmann, Thomas Wetzel
      First page: 28
      Abstract: The lifetime of the battery significantly influences the acceptance of electric vehicles. Calendar aging contributes to the limited operating lifetime of lithium-ion batteries. Therefore, its consideration in addition to cyclical aging is essential to understand battery degradation. This study consequently examines the same graphite/NCA pouch cell that was the subject of previously published cyclic aging tests. The cells were aged at different temperatures and states of charge. The self-discharge was continuously monitored, and after each storage period, the remaining capacity and the impedance were measured. The focus of this publication is on the correlation of the measurements. An aging correlation is obtained that is valid for a wide range of temperatures and states of charge. The results show an accelerated capacity fade and impedance rise with increasing temperature, following the law of Arrhenius. However, the obtained data do also indicate that there is no path dependency, i.e., earlier periods at different temperature levels do not affect the present degradation rate. A large impact of the storage state of charge at 100% is evident, whereas the influence is small below 80%. Instead of the commonly applied square root of the time function, our results are in excellent agreement with an exponential function.
      Citation: Batteries
      PubDate: 2021-04-30
      DOI: 10.3390/batteries7020028
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 29: Global Warming Potential of a New
           Waterjet-Based Recycling Process for Cathode Materials of Lithium-Ion
           Batteries

    • Authors: Leonard Kurz, Mojtaba Faryadras, Ines Klugius, Frederik Reichert, Andreas Scheibe, Matthias Schmidt, Ralf Wörner
      First page: 29
      Abstract: Due to the increasing demand for battery electric vehicles (BEVs), the need for vehicle battery raw materials is increasing. The traction battery (TB) of an electric vehicle, usually a lithium-ion battery (LIB), represents the largest share of a BEV’s CO2 footprint. To reduce this carbon footprint sustainably and to keep the raw materials within a closed loop economy, suitable and efficient recycling processes are essential. In this life cycle assessment (LCA), the ecological performance of a waterjet-based direct recycling process with minimal use of resources and energy is evaluated; only the recycling process is considered, waste treatment and credits for by-products are not part of the analysis. Primary data from a performing recycling company were mainly used for the modelling. The study concludes that the recycling of 1 kg of TB is associated with a global warming potential (GWP) of 158 g CO2 equivalents (CO2e). Mechanical removal using a water jet was identified as the main driver of the recycling process, followed by an air purification system. Compared to conventional hydro- or pyrometallurgical processes, this waterjet-based recycling process could be attributed an 8 to 26 times lower GWP. With 10% and 20% reuse of recyclate in new cells, the GWP of TBs could be reduced by 4% and 8%, respectively. It has been shown that this recycling approach can be classified as environmentally friendly.
      Citation: Batteries
      PubDate: 2021-05-01
      DOI: 10.3390/batteries7020029
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 30: Comparative Study of Kilowatt-Scale Vanadium
           Redox Flow Battery Stacks Designed with Serpentine Flow Fields and Split
           Manifolds

    • Authors: Ravendra Gundlapalli, Sreenivas Jayanti
      First page: 30
      Abstract: A low-pressure drop stack design with minimal shunt losses was explored for vanadium redox flow batteries, which, due to their low energy density, are used invariably in stationary applications. Three kilowatt-scale stacks, having cell sizes in the range of 400 to 1500 cm2, were built with thick graphite plates grooved with serpentine flow fields and external split manifolds for electrolyte circulation, and they were tested over a range of current densities and flow rates. The results show that stacks of different cell sizes have different optimal flow rate conditions, but under their individual optimal flow conditions, all three cell sizes exhibit similar electrochemical performance including stack resistivity. Stacks having larger cell sizes can be operated at lower stoichiometric factors, resulting in lower parasitic pumping losses. Further, these can be operated at a fixed flow rate for power variations of ±25% without any significant changes in discharge capacity and efficiency; this is attributed to the use of serpentine flow fields, which ensure uniform distribution of the electrolyte over a range of flow rates and cell sizes.
      Citation: Batteries
      PubDate: 2021-05-06
      DOI: 10.3390/batteries7020030
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 31: Advanced Monitoring and Prediction of the
           Thermal State of Intelligent Battery Cells in Electric Vehicles by
           Physics-Based and Data-Driven Modeling

    • Authors: Jan Kleiner, Magdalena Stuckenberger, Lidiya Komsiyska, Christian Endisch
      First page: 31
      Abstract: Novel intelligent battery systems are gaining importance with functional hardware on the cell level. Cell-level hardware allows for advanced battery state monitoring and thermal management, but also leads to additional thermal interactions. In this work, an electro-thermal framework for the modeling of these novel intelligent battery cells is provided. Thereby, a lumped thermal model, as well as a novel neural network, are implemented in the framework as thermal submodels. For the first time, a direct comparison of a physics-based and a data-driven thermal battery model is performed in the same framework. The models are compared in terms of temperature estimation with regard to accuracy. Both models are very well suited to represent the thermal behavior in novel intelligent battery cells. In terms of accuracy and computation time, however, the data-driven neural network approach with a Nonlinear AutoregRessive network with eXogeneous input (NARX) shows slight advantages. Finally, novel applications of temperature prediction in battery electric vehicles are presented and the applicability of the models is illustrated. Thereby, the conventional prediction of the state of power is extended by simultaneous temperature prediction. Additionally, temperature forecasting is used for pre-conditioning by advanced cooling system regulation to enable energy efficiency and fast charging.
      Citation: Batteries
      PubDate: 2021-05-11
      DOI: 10.3390/batteries7020031
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 32: Electrical Characterization of Li-Ion Battery
           Modules for Second-Life Applications

    • Authors: Daniel Kehl, Torben Jennert, Frank Lienesch, Michael Kurrat
      First page: 32
      Abstract: The reuse and repurposing of lithium-ion batteries for transportation in stationary energy systems improve the economic value of batteries. A precise suitability test at the beginning of the second life is therefore necessary. Common methods such as electrochemical impedance spectroscopy (EIS) and current interrupt (CI) analysis, as well as capacity analysis, can be used for testing. In this paper, these methods are studied from the aspects of test duration, sensitivity and acquisition costs of the measuring instruments. For this purpose, tests are carried out on battery modules, which were used for transportation. It is shown that subtle differences are better detected with EIS and less accurately with the CI method. The test duration is fastest with the CI method, followed by EIS and the capacity test. Strongly aged modules are reliably detected with all methods.
      Citation: Batteries
      PubDate: 2021-05-13
      DOI: 10.3390/batteries7020032
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 33: The Influence of Li4Ti5O12 Preparation Method
           on Lithium-Ion Capacitor Performance

    • Authors: Taofeek Akintola, Annadanesh Shellikeri, Tawakalt Akintola, Jim P. Zheng
      First page: 33
      Abstract: In this study, the importance of the preparation technique of Li4Ti5O12 (LTO) anode on its performance in a lithium-ion capacitor (LIC) application was investigated. These desired characteristics include energy density, rate capability, and cycle life. The samples were prepared using three approaches, and the same sol-gel synthesis procedure is applied to obtain phase-pure samples and keep the structural properties similar. The influence of these methods on the LTO anodes was then explored in both half-cell and full-cell LIC devices with an activated carbon (AC) cathode. It was observed that the samples had similar specific capacities and energy densities at low specific currents. However, significant differences were observed in the samples’ morphological properties, the rate capability, and the full-cell cycle life performance. Electrochemical impedance spectroscopy was used to identify the electrochemical kinetics and revealed that the LIC with the best performance was influenced by the LTO anode having the least charge transfer and diffusion resistances prepared using a surfactant. This was due to the small particle size, good particle dispersion, and high specific surface area of the LTO anode. This result points to the importance of the choice of synthesis technique in LIC material’s overall performance.
      Citation: Batteries
      PubDate: 2021-05-20
      DOI: 10.3390/batteries7020033
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 34: Factors Influencing the Formation of Sodium
           Hydroxide by an Ion Exchange Membrane Cell

    • Authors: Jimmy Aurelio Rosales-Huamani, Juan Taumaturgo Medina-Collana, Zoila Margarita Diaz-Cordova, Jorge Alberto Montaño-Pisfil
      First page: 34
      Abstract: The present study aimed to evaluate the factors that influence the formation of sodium hydroxide (NaOH) by means of an electrolytic cell with ion exchange membranes. To achieve this experiment, the NaOH production cell had to be designed and built inexpensively, using graphite electrodes. The operational parameters in our study were: initial NaOH concentration, applied voltage, and temperature. All experiments were carried out using model NaCl solutions with a concentration of 40 g/L for 150 min. The results of the experiment were that the NaOH concentration, conductivity, and pH presented an increasing linear trend with the electrolysis time. Finally, it was possible to obtain the efficiency level of the electric current in our investigation, which was an average of 80.2%, that indicated good performance of the built cell.
      Citation: Batteries
      PubDate: 2021-05-20
      DOI: 10.3390/batteries7020034
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 35: Unified Evaluation Framework for Stochastic
           Algorithms Applied to Remaining Useful Life Prognosis Problems

    • Authors: Mikel Arrinda, Mikel Oyarbide, Haritz Macicior, Eñaut Muxika
      First page: 35
      Abstract: A unified evaluation framework for stochastic tools is developed in this paper. Firstly, we provide a set of already existing quantitative and qualitative metrics that rate the relevant aspects of the performance of a stochastic prognosis algorithm. Secondly, we provide innovative guidelines to detect and minimize the effect of side aspects that interact on the algorithms’ performance. Those aspects are related with the input uncertainty (the uncertainty on the data and the prior knowledge), the parametrization method and the uncertainty propagation method. The proposed evaluation framework is contextualized on a Lithium-ion battery Remaining Useful Life prognosis problem. As an example, a Particle Filter is evaluated. On this example, two different data sets taken from NCA aged batteries and two semi-empirical aging models available in the literature fed up the Particle Filter under evaluation. The obtained results show that the proposed framework gives enough details to take decisions about the viability of the chosen algorithm.
      Citation: Batteries
      PubDate: 2021-05-25
      DOI: 10.3390/batteries7020035
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 36: Determination of the Distribution of
           Relaxation Times by Means of Pulse Evaluation for Offline and Online
           Diagnosis of Lithium-Ion Batteries

    • Authors: Erik Goldammer, Julia Kowal
      First page: 36
      Abstract: The distribution of relaxation times (DRT) analysis of impedance spectra is a proven method to determine the number of occurring polarization processes in lithium-ion batteries (LIBs), their polarization contributions and characteristic time constants. Direct measurement of a spectrum by means of electrochemical impedance spectroscopy (EIS), however, suffers from a high expenditure of time for low-frequency impedances and a lack of general availability in most online applications. In this study, a method is presented to derive the DRT by evaluating the relaxation voltage after a current pulse. The method was experimentally validated using both EIS and the proposed pulse evaluation to determine the DRT of automotive pouch-cells and an aging study was carried out. The DRT derived from time domain data provided improved resolution of processes with large time constants and therefore enabled changes in low-frequency impedance and the correlated degradation mechanisms to be identified. One of the polarization contributions identified could be determined as an indicator for the potential risk of plating. The novel, general approach for batteries was tested with a sampling rate of 10 Hz and only requires relaxation periods. Therefore, the method is applicable in battery management systems and contributes to improving the reliability and safety of LIBs.
      Citation: Batteries
      PubDate: 2021-06-01
      DOI: 10.3390/batteries7020036
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 37: Methodology for the Optimisation of Battery
           Hybrid Energy Storage Systems for Mass and Volume Using a Power-To-Energy
           Ratio Analysis

    • Authors: Gregory Tzermias, Sam Akehurst, Richard Burke, Chris Brace, Sunoj George, Johan Bernards, Christopher Smith
      First page: 37
      Abstract: Increasingly stringent emission regulations and environmental concerns have propelled the development of electrification technology in the transport industry. Yet, the greatest hurdle to developing fully electric vehicles is electrochemical energy storage, which struggles to achieve profitable specific power, specific energy and cost targets. Hybrid energy storage systems (HESSs), which combine energy- and power-optimised sources, seem to be the most promising solution for improving the overall performance of energy storage. The potential for gravimetric and volumetric reduction is strictly dependent on the overall power-to-energy ratio (PE ratio) of the application, packaging factors, the minimum and maximum PE ratio achievable for the system’s energy- and power-optimised sources and the performance of power electronics. This paper presents a simple optimisation methodology that considers these factors and identifies the optimal HESS requirements that may present new opportunities for a variety of vehicles where low weight and volume are of high importance. The simplicity of the method means that decisions relating to a HESS can be made earlier in the system design process. This method of analysis showed that a battery HESS has the potential to reduce cell mass and volume by over 30% for applications that are well suited to optimal HESS characteristics.
      Citation: Batteries
      PubDate: 2021-06-03
      DOI: 10.3390/batteries7020037
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 38: A Comparison of Lithium-Ion Cell Performance
           across Three Different Cell Formats

    • Authors: Grace Bridgewater, Matthew J. Capener, James Brandon, Michael J. Lain, Mark Copley, Emma Kendrick
      First page: 38
      Abstract: To investigate the influence of cell formats during a cell development programme, lithium-ion cells have been prepared in three different formats. Coin cells, single layer pouch cells, and stacked pouch cells gave a range of scales of almost three orders of magnitude. The cells used the same electrode coatings, electrolyte and separator. The performance of the different formats was compared in long term cycling tests and in measurements of resistance and discharge capacities at different rates. Some test results were common to all three formats. However, the stacked pouch cells had higher discharge capacities at higher rates. During cycling tests, there were indications of differences in the predominant degradation mechanism between the stacked cells and the other two cell formats. The stacked cells showed faster resistance increases, whereas the coin cells showed faster capacity loss. The difference in degradation mechanism can be linked to the different thermal and mechanical environments in the three cell formats. The correlation in the electrochemical performance between coin cells, single layer pouch cells, and stacked pouch cells shows that developments within a single cell format are likely to lead to improvements across all cell formats.
      Citation: Batteries
      PubDate: 2021-06-08
      DOI: 10.3390/batteries7020038
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 39: Methodology for Determining Time-Dependent
           Lead Battery Failure Rates from Field Data

    • Authors: Rafael Conradt, Frederic Heidinger, Kai Peter Birke
      First page: 39
      Abstract: The safety requirements in vehicles continuously increase due to more automated functions using electronic components. Besides the reliability of the components themselves, a reliable power supply is crucial for a safe overall system. Different architectures for a safe power supply consider the lead battery as a backup solution for safety-critical applications. Various ageing mechanisms influence the performance of the battery and have an impact on its reliability. In order to qualify the battery with its specific failure modes for use in safety-critical applications, it is necessary to prove this reliability by failure rates. Previous investigations determine the fixed failure rates of lead batteries using data from teardown analyses to identify the battery failure modes but did not include the lifetime of these batteries examined. Alternatively, lifetime values of battery replacements in workshops without knowing the reason for failure were used to determine the overall time-dependent failure rate. This study presents a method for determining reliability models of lead batteries by investigating individual failure modes. Since batteries are subject to ageing, the analysis of lifetime values of different failure modes results in time-dependent failure rates of different magnitudes. The failure rates of the individual failure modes develop with different shapes over time, which allows their ageing behaviour to be evaluated.
      Citation: Batteries
      PubDate: 2021-06-15
      DOI: 10.3390/batteries7020039
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 40: Comparison of Aqueous- and Non-Aqueous-Based
           Binder Polymers and the Mixing Ratios for Zn//MnO2 Batteries with Mildly
           Acidic Aqueous Electrolytes

    • Authors: Oliver Fitz, Stefan Ingenhoven, Christian Bischoff, Harald Gentischer, Kai Peter Birke, Dragos Saracsan, Daniel Biro
      First page: 40
      Abstract: Considering the literature for aqueous rechargeable Zn//MnO2 batteries with acidic electrolytes using the doctor blade coating of the active material (AM), carbon black (CB), and binder polymer (BP) for the positive electrode fabrication, different binder types with (non-)aqueous solvents were introduced so far. Furthermore, in most of the cases, relatively high passive material (CB+BP) shares ~30 wt% were applied. The first part of this work focuses on different selected BPs: polyacrylonitrile (PAN), carboxymethyl cellulose (CMC), styrene butadiene rubber (SBR), cellulose acetate (CA), and nitrile butadiene rubber (NBR). They were used together with (non-)aqueous solvents: DI-water, methyl ethyl ketone (MEK), and dimethyl sulfoxide (DMSO). By performing mechanical, electrochemical and optical characterizations, a better overall performance of the BPs using aqueous solvents was found in aqueous 2 M ZnSO4 + 0.1 M MnSO4 electrolyte (i.e., BP LA133: 150 mAh·g−1 and 189 mWh·g−1 @ 160 mA·g−1). The second part focuses on the mixing ratio of the electrode components, aiming at the decrease of the commonly used passive material share of ~30 wt% for an industrial-oriented electrode fabrication, while still maintaining the electrochemical performance. Here, the absolute CB share and the CB/BP ratio are found to be important parameters for an application-oriented electrode fabrication (i.e., high energy/power applications).
      Citation: Batteries
      PubDate: 2021-06-18
      DOI: 10.3390/batteries7020040
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 41: Absolute Local Quantification of Li as
           Function of State-of-Charge in All-Solid-State Li Batteries via 2D MeV
           Ion-Beam Analysis

    • Authors: Sören Möller, Takahiro Satoh, Yasuyuki Ishii, Britta Teßmer, Rayan Guerdelli, Tomihiro Kamiya, Kazuhisa Fujita, Kota Suzuki, Yoshiaki Kato, Hans-Dieter Wiemhöfer, Kunioki Mima, Martin Finsterbusch
      First page: 41
      Abstract: Direct observation of the lithiation and de-lithiation in lithium batteries on the component and microstructural scale is still difficult. This work presents recent advances in MeV ion-beam analysis, enabling quantitative contact-free analysis of the spatially-resolved lithium content and state-of-charge (SoC) in all-solid-state lithium batteries via 3 MeV proton-based characteristic x-ray and gamma-ray emission analysis. The analysis is demonstrated on cross-sections of ceramic and polymer all-solid-state cells with LLZO and MEEP/LIBOB solid electrolytes. Different SoC are measured ex-situ and one polymer-based operando cell is charged at 333 K during analysis. The data unambiguously show the migration of lithium upon charging. Quantitative lithium concentrations are obtained by taking the physical and material aspects of the mixed cathodes into account. This quantitative lithium determination as a function of SoC gives insight into irreversible degradation phenomena of all-solid-state batteries during the first cycles and locations of immobile lithium. The determined SoC matches the electrochemical characterization within uncertainties. The presented analysis method thus opens up a completely new access to the state-of-charge of battery cells not depending on electrochemical measurements. Automated beam scanning and data-analysis algorithms enable a 2D quantitative Li and SoC mapping on the µm-scale, not accessible with other methods.
      Citation: Batteries
      PubDate: 2021-06-20
      DOI: 10.3390/batteries7020041
      Issue No: Vol. 7, No. 2 (2021)
       
  • Batteries, Vol. 7, Pages 4: Design Considerations for Fast Charging
           Lithium Ion Cells for NMC/MCMB Electrode Pairs

    • Authors: William Yourey, Yanbao Fu, Ning Li, Vincent Battaglia, Wei Tong
      First page: 4
      Abstract: Lithium ion cells that can be quickly charged are of critical importance for the continued and accelerated penetration of electric vehicles (EV) into the consumer market. Considering this, the U.S. Department of Energy (DOE) has set a cell recharge time goal of 10–15 min. The following study provides an investigation into the effect of cell design, specifically negative to positive matching ratio (1.2:1 vs. 1.7:1) on fast charging performance. By using specific charging procedures based on negative electrode performance, as opposed to the industrial standard constant current constant voltage procedures, we show that the cells with a higher N:P ratio can be charged to ~16% higher capacity in the ten-minute time frame. Cells with a higher N:P ratio also show similar cycle life performance to those with a conventional N:P ratio, despite the fact that these cells experience a much higher irreversible capacity loss, leading to a lower reversible specific capacity.
      Citation: Batteries
      PubDate: 2021-01-05
      DOI: 10.3390/batteries7010004
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 5: Titanium Activation in Prussian Blue Based
           Electrodes for Na-ion Batteries: A Synthesis and Electrochemical Study

    • Authors: Min Li, Angelo Mullaliu, Stefano Passerini, Marco Giorgetti
      First page: 5
      Abstract: Sodium titanium hexacyanoferrate (TiHCF, Na0.86Ti0.73[Fe(CN)6]·3H2O) is synthesized by a simple co-precipitation method in this study. Its crystal structure, chemical composition, and geometric/electronic structural information are investigated by X-ray powder diffraction (XRPD), microwave plasma-atomic emission spectroscopy (MP-AES), and X-ray absorption spectroscopy (XAS). The electroactivity of TiHCF as a host for Li-ion and Na-ion batteries is studied in organic electrolytes. The results demonstrate that TiHCF is a good positive electrode material for both Li-ion and Na-ion batteries. Surprisingly, however, the material shows better electrochemical performance as a Na-ion host, offering a capacity of 74 mAh g−1 at C/20 and a 94.5% retention after 50 cycles. This is due to the activation of Ti towards the redox reaction, making TiHCF a good candidate electrode material for Na-ion batteries.
      Citation: Batteries
      PubDate: 2021-01-07
      DOI: 10.3390/batteries7010005
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 6: Effects of the Nail Geometry and Humidity on
           the Nail Penetration of High-Energy Density Lithium Ion Batteries

    • Authors: Stefan Doose, Wolfgang Haselrieder, Arno Kwade
      First page: 6
      Abstract: Internal short-circuit tests were carried out in a battery safety investigation chamber to determine the behavior of batteries during the nail penetration test. So far, systematic investigations regarding the test setup and its influence are rarely found in the literature. Especially, to improve the comparability of the multitude of available results, it is essential to understand the effects of the geometric, operating and ambient parameters. In this study commercial lithium ion batteries with a capacity of 5.3 and 3.3 Ah were used to study the influence of the varied parameters on the voltage drop, the development of surface temperatures and of infrared active gas species. We studied both the influence of the geometry of the penetrating nail and concentration of water in the inert atmosphere especially on the quantities of the reaction products under variation of cell capacity. It could be shown that the geometry of the nail, within certain limits, has no influence on the processes of the thermal runaway of high energy density lithium ion batteries (LIBs). However, a change in capacity from 5.3 to 3.3 Ah shows that in particular the gaseous reaction products differ: The standardized gas concentrations show a higher measurable concentration of all gases except CO for the 3.3 Ah LIBs. This circumstance can be explained by the intensity of the reactions due to the different battery capacities: In the 5.3 Ah cells a larger amount of unreacted material is immediately discharged from the reaction center, and by the different available amounts of oxidizing reaction partners. An increase of the water content in the surrounding atmosphere during the thermal runaway leads to a reduction of the measurable gas concentrations of up to 36.01%. In general, all measured concentrations decrease. With increased water content more reaction products from the atmosphere can be directly bound or settle as condensate on surfaces.
      Citation: Batteries
      PubDate: 2021-01-12
      DOI: 10.3390/batteries7010006
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 7: The Effect of Input Parameter Variation on the
           Accuracy of a Vanadium Redox Flow Battery Simulation Model

    • Authors: Christina Zugschwert, Jan Dundálek, Stephan Leyer, Jean-Régis Hadji-Minaglou, Juraj Kosek, Karl-Heinz Pettinger
      First page: 7
      Abstract: Accurately predicting battery behavior, while using low input data, is highly desirable in embedded simulation architectures like grid or integrated energy system analysis. Currently, the available vanadium redox flow battery (VRFB) models achieve highly accurate predictions of electrochemical behavior or control algorithms, while the optimization of the required input data scope is neglected. In this study, a parametrization tool for a DC grey box simulation model is developed using measurements with a 10 kW/100 kWh VRFB. An objective function is applied to optimize the required input data scope while analyzing simulation accuracy. The model is based on a differential-algebraic system, and an optimization process allows model parameter estimation and verification while reducing the input data scope. Current losses, theoretical storage capacity, open circuit voltage, and ohmic cell resistance are used as fitting parameters. Internal electrochemical phenomena are represented by a self-discharge current while material related losses are represented by a changing ohmic resistance. Upon reducing input data the deviation between the model and measurements shows an insignificant increase of 2% even for a 60% input data reduction. The developed grey box model is easily adaptable to other VRFB and is highly integrable into an existing energy architecture.
      Citation: Batteries
      PubDate: 2021-01-19
      DOI: 10.3390/batteries7010007
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 8: Lithium-Ion Batteries: Latest Advances and
           Prospects

    • Authors: Mohammad Rahimi
      First page: 8
      Abstract: The anthropogenic release of greenhouse gases, especially carbon dioxide (CO2), has resulted in a notable climate change and an increase in global average temperature since the mid-20th century [...]
      Citation: Batteries
      PubDate: 2021-01-20
      DOI: 10.3390/batteries7010008
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 9: Key Figure Based Incoming Inspection of
           Lithium-Ion Battery Cells

    • Authors: Kerstin Ryll, Louisa Hoffmann, Oliver Landrath, Frank Lienesch, Michael Kurrat
      First page: 9
      Abstract: The cell characterization in the incoming inspection is an important but time and cost intensive process step. In order to obtain reliable parameters to evaluate and classify the cells, it is essential to design the test procedures in such a way that the parameters derived from the data allow the required statements about the cells. Before the focus is placed on the evaluation of cell properties, it is therefore necessary to design the test procedures appropriately. In the scope of the investigations two differently designed incoming inspection routines were carried out on 230 commercial lithium-ion battery cells (LIBs) with the aim of deriving recommendations for optimal test procedures. The derived parameters of the test strategies were compared and statistically evaluated. Subsequently, key figures for the classification were identified. As a conclusion, the capacity was confirmed as an already known important parameter and the average cell voltage was identified as a possibility to replace the usually used internal resistance. With regard to capacity, the integration of CV steps in the discharging processes enables the determination independently from the C-rate. For the average voltage cycles with high C-rates are particularly meaningful because of the significant higher scattering due to the overvoltage parts.
      Citation: Batteries
      PubDate: 2021-01-26
      DOI: 10.3390/batteries7010009
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 10: Acknowledgement to Reviewers of Batteries in
           2020

    • Authors: Batteries Editorial Office Batteries Editorial Office
      First page: 10
      Abstract: Peer review is the driving force of journal development, and reviewers are gatekeepers who ensure that Batteries maintains its standards for the high quality of its published papers [...]
      Citation: Batteries
      PubDate: 2021-01-28
      DOI: 10.3390/batteries7010010
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 11: Infiltrated and Isostatic Laminated NCM and
           LTO Electrodes with Plastic Crystal Electrolyte Based on Succinonitrile
           for Lithium-Ion Solid State Batteries

    • Authors: Matthias Coeler, Vanessa van Laack, Frederieke Langer, Annegret Potthoff, Sören Höhn, Sebastian Reuber, Katharina Koscheck, Mareike Wolter
      First page: 11
      Abstract: We report a new process technique for electrode manufacturing for all solid-state batteries. Porous electrodes are manufactured by a tape casting process and subsequently infiltrated by a plastic crystal polymer electrolyte (PCPE). With a following isostatic lamination process, the PCPE was further integrated deeply into the porous electrode layer, forming a composite electrode. The PCPE comprises the plastic crystal succinonitrile (SN), lithium conductive salt LiTFSI and polyacrylonitrile (PAN) and exhibits suitable thermal, rheological (ƞ = 0.6 Pa s @ 80 °C 1 s−1) and electrochemical properties (σ > 10−4 S/cm @ 45 °C). We detected a lowered porosity of infiltrated and laminated electrodes through Hg porosimetry, showing a reduction from 25.6% to 2.6% (NCM infiltrated to laminated) and 32.9% to 4.0% (LTO infiltrated to laminated). Infiltration of PCPE into the electrodes was further verified by FESEM images and EDS mapping of sulfur content of the conductive salt. Cycling tests of full cells with NCM and LTO electrodes with PCPE separator at 45 °C showed up to 165 mAh/g at 0.03C over 20 cycles, which is about 97% of the total usable LTO capacity with a coulomb efficiency of between 98 and 99%. Cycling tests at 0.1C showed a capacity of ~128 mAh/g after 40 cycles. The C-rate of 0.2C showed a mean capacity of 127 mAh/g. In summary, we could manufacture full cells using a plastic crystal polymer electrolyte suitable for NCM and LTO active material, which is easily to be integrated into porous electrodes and which is being able to be used in future cell concepts like bipolar stacked cells.
      Citation: Batteries
      PubDate: 2021-02-03
      DOI: 10.3390/batteries7010011
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 12: Application Dependent End-of-Life Threshold
           Definition Methodology for Batteries in Electric Vehicles

    • Authors: Mikel Arrinda, Mikel Oyarbide, Haritz Macicior, Eñaut Muxika, Hartmut Popp, Marcus Jahn, Boschidar Ganev, Iosu Cendoya
      First page: 12
      Abstract: The end-of-life event of the battery system of an electric vehicle is defined by a fixed end-of-life threshold value. However, this kind of end-of-life threshold does not capture the application and battery characteristics and, consequently, it has a low accuracy in describing the real end-of-life event. This paper proposes a systematic methodology to determine the end-of-life threshold that describes accurately the end-of-life event. The proposed methodology can be divided into three phases. In the first phase, the health indicators that represent the aging behavior of the battery are defined. In the second phase, the application specifications and battery characteristics are evaluated to generate the end-of-life criteria. Finally, in the third phase, the simulation environment used to calculate the end-of-life threshold is designed. In this third phase, the electric-thermal behavior of the battery at different aging conditions is simulated using an electro-thermal equivalent circuit model. The proposed methodology is applied to a high-energy electric vehicle application and to a high-power electric vehicle application. The stated hypotheses and the calculated end-of-life threshold of the high-energy application are empirically validated. The study shows that commonly assumed 80 or 70% EOL thresholds could lead to mayor under or over lifespan estimations.
      Citation: Batteries
      PubDate: 2021-02-11
      DOI: 10.3390/batteries7010012
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 13: Grid Impacts of Uncoordinated Fast Charging
           of Electric Ferry

    • Authors: Rajib Baran Roy, Sanath Alahakoon, Shantha Jayasinghe Arachchillage
      First page: 13
      Abstract: The battery energy storage system (BESS) is an indispensable part of an electric fleet (EF) which needs to be charged by electricity from local grid when the fleet is in the dockyard. The uncoordinated fast charging of BESS in Grid to Ferry (G2F) mode imposes sudden increments of load in the power grid, which is analyzed by a simulated model of grid connected marine load. The probable impact on system stability is examined by MATLAB Simulink and Power World Simulator based models. According to simulation results for IEEE 5 bus system, voltage unbalance factors are 0.01% and 200% for all buses at fundamental and third harmonics frequencies, respectively. The total harmonic distortion (THD) at fundamental frequency becomes 0.16%, 0.16%, and 0.18%, respectively, for three cases. The transient, voltage reactive power (V-Q), and voltage real power (V-P) sensitivity analysis are performed for 7 bus system with load increment contingencies. According to simulation results, the V-Q sensitivity for the assigned contingency is increased by the addition of a shunt generator to the load bus with lowest bus voltage. In case of V-P sensitivity for the selected contingency, the load buses share power among them, and the nose point is attained at maximum shift of power with high V-Q sensitivity.
      Citation: Batteries
      PubDate: 2021-02-17
      DOI: 10.3390/batteries7010013
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 14: A Flexible Model for Benchmarking the Energy
           Usage of Automotive Lithium-Ion Battery Cell Manufacturing

    • Authors: Asanthi Jinasena, Odne Stokke Burheim, Anders Hammer Strømman
      First page: 14
      Abstract: The increasing use of electric vehicle batteries in the world has a significant impact on both society and the environment. Thus, there is a need for the availability of transparent information on resource allocation. Battery manufacturing process details in this regard are not available in academia or the public. The available energy data on manufacturing has a high variation. Furthermore, different process steps have different energy and material demands. A process model can benchmark the energy usage, provide detailed process data, and compare various cell productions which in turn can be used in life-cycle assessment studies to reduce the variation and provide directions for improvements. Therefore, a cell manufacturing model is developed for the calculation of energy and material demands for different battery types, plant capacities, and process steps. The model consists of the main process steps, machines, intermediate products and building service units. Furthermore, the results are validated using literature values. For a case study of a 2 GWh plant that produces prismatic NMC333 cells, the total energy requirement on a theoretical and optimal basis is suggested to be 44.6Whinproduction/Whcellcapacity. This energy consumption in producing batteries is dominated by electrode drying, and dry room. Energy usage for a variety of cell types for a similar plant capacity shows that the standard deviation in the results is low (47.23±13.03Wh/Wh).
      Citation: Batteries
      PubDate: 2021-02-22
      DOI: 10.3390/batteries7010014
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 15: Estimate e-Golf Battery State Using
           Diagnostic Data and a Digital Twin

    • Authors: Lukas Merkle, Michael Pöthig, Florian Schmid
      First page: 15
      Abstract: Li-ion battery packs are the heart of modern electric vehicles. Due to their perishable nature, it is crucial to supervise them closely. In addition to on-board supervision over safety and range, insights into the battery’s degradation are also becoming increasingly important, not only for the vehicle manufacturers but also for vehicle users. The concept of digital twins has already emerged on the field of automotive technology, and can also help to digitalize the vehicle’s battery. In this work, we set up a data pipeline and digital battery twin to track the battery state, including State of charge (SOC) and State of Health (SOH). To achieve this goal, we reverse-engineer the diagnostics interface of a 2014 e-Golf to query for UDS messages containing both battery pack and cell-individual data. An OBD logger records the data with edge-processing capability. Pushing this data into the cloud twin system using IoT-technology, we can fit battery models to the data and infer for example, cell individual internal resistance from them. We find that the resistances of the cells differ by a magnitude of two. Furthermore, we propose an architecture for the battery twin in which the twin fleet shares resources like models by encapsulating them in Docker containers run on a cloud stack. By using web technology, we present the analyzed results on a web interface.
      Citation: Batteries
      PubDate: 2021-02-24
      DOI: 10.3390/batteries7010015
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 16: Thermophysical Characterization of a Layered
           P2 Type Structure Na0.53MnO2 Cathode Material for Sodium Ion Batteries

    • Authors: Ijaz Ul Mohsin, Carlos Ziebert, Magnus Rohde, Hans Jürgen Seifert
      First page: 16
      Abstract: Over the last decade, the demand for safer batteries with excellent performance and lower costs has been intensively increasing. The abundantly available precursors and environmental friendliness are generating more and more interest in sodium ion batteries (SIBs), especially because of the lower material costs compared to Li-ion batteries. Therefore, significant efforts are being dedicated to investigating new cathode materials for SIBs. Since the thermal characterization of cathode materials is one of the key factors for designing safe batteries, the thermophysical properties of a commercial layered P2 type structure Na0.53MnO2 cathode material in powder form were measured in the temperature range between −20 and 1200 °C by differential scanning calorimetry (DSC), laser flash analysis (LFA), and thermogravimetry (TG). The thermogravimetry (TG) was combined with mass spectrometry (MS) to study the thermal decomposition of the cathode material with respect to the evolved gas analysis (EGA) and was performed from room temperature up to 1200 °C. The specific heat (Cp) and the thermal diffusivity (α) were measured up to 400 °C because beyond this temperature, the cathode material starts to decompose. The thermal conductivity (λ) as a function of temperature was calculated from the thermal diffusivity, the specific heat capacity, and the density. Such thermophysical data are highly relevant and important for thermal simulation studies, thermal management, and the mitigation of thermal runaway.
      Citation: Batteries
      PubDate: 2021-03-01
      DOI: 10.3390/batteries7010016
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 17: State-of-Charge Monitoring and Battery
           Diagnosis of Different Lithium Ion Chemistries Using Impedance
           Spectroscopy

    • Authors: Peter Kurzweil, Wolfgang Scheuerpflug
      First page: 17
      Abstract: For lithium iron phosphate batteries (LFP) in aerospace applications, impedance spectroscopy is applicable in the flat region of the voltage-charge curve. The frequency-dependent pseudocapacitance at 0.15 Hz is presented as useful state-of-charge (SOC) and state-of-health (SOH) indicator. For the same battery type, the prediction error of pseudocapacitance is better than 1% for a quadratic calibration curve, and less than 36% for a linear model. An approximately linear correlation between pseudocapacitance and Ah battery capacity is observed as long as overcharge and deep discharge are avoided. We verify the impedance method in comparison to the classical constant-current discharge measurements. In the case of five examined lithium-ion chemistries, the linear trend of impedance and SOC is lost if the slope of the discharge voltage curve versus SOC changes. With nickel manganese cobalt (NMC), high impedance modulus correlates with high SOC above 70%.
      Citation: Batteries
      PubDate: 2021-03-04
      DOI: 10.3390/batteries7010017
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 18: A Performance and Cost Overview of Selected
           Solid-State Electrolytes: Race between Polymer Electrolytes and Inorganic
           Sulfide Electrolytes

    • Authors: Duygu Karabelli, Kai Peter Birke, Max Weeber
      First page: 18
      Abstract: Electrolytes are key components in electrochemical storage systems, which provide an ion-transport mechanism between the cathode and anode of a cell. As battery technologies are in continuous development, there has been growing demand for more efficient, reliable and environmentally friendly materials. Solid-state lithium ion batteries (SSLIBs) are considered as next-generation energy storage systems and solid electrolytes (SEs) are the key components for these systems. Compared to liquid electrolytes, SEs are thermally stable (safer), less toxic and provide a more compact (lighter) battery design. However, the main issue is the ionic conductivity, especially at low temperatures. So far, there are two popular types of SEs: (1) inorganic solid electrolytes (InSEs) and (2) polymer electrolytes (PEs). Among InSEs, sulfide-based SEs are providing very high ionic conductivities (up to 10−2 S/cm) and they can easily compete with liquid electrolytes (LEs). On the other hand, they are much more expensive than LEs. PEs can be produced at less cost than InSEs but their conductivities are still not sufficient for higher performances. This paper reviews the most efficient SEs and compares them in terms of their performances and costs. The challenges associated with the current state-of-the-art electrolytes and their cost-reduction potentials are described.
      Citation: Batteries
      PubDate: 2021-03-05
      DOI: 10.3390/batteries7010018
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 19: Inline Monitoring of Battery Electrode
           Lamination Processes Based on Acoustic Measurements

    • Authors: Ruben Leithoff, Nikolas Dilger, Frank Duckhorn, Stefan Blume, Dario Lembcke, Constanze Tschöpe, Christoph Herrmann, Klaus Dröder
      First page: 19
      Abstract: Due to the energy transition and the growth of electromobility, the demand for lithium-ion batteries has increased in recent years. Great demands are being placed on the quality of battery cells and their electrochemical properties. Therefore, the understanding of interactions between products and processes and the implementation of quality management measures are essential factors that requires inline capable process monitoring. In battery cell lamination processes, a typical problem source of quality issues can be seen in missing or misaligned components (anodes, cathodes and separators). An automatic detection of missing or misaligned components, however, has not been established thus far. In this study, acoustic measurements to detect components in battery cell lamination were applied. Although the use of acoustic measurement methods for process monitoring has already proven its usefulness in various fields of application, it has not yet been applied to battery cell production. While laminating battery electrodes and separators, acoustic emissions were recorded. Signal analysis and machine learning techniques were used to acoustically distinguish the individual components that have been processed. This way, the detection of components with a balanced accuracy of up to 83% was possible, proving the feasibility of the concept as an inline capable monitoring system.
      Citation: Batteries
      PubDate: 2021-03-08
      DOI: 10.3390/batteries7010019
      Issue No: Vol. 7, No. 1 (2021)
       
  • Batteries, Vol. 7, Pages 20: Impact of Test Conditions While Screening
           Lithium-Ion Batteries for Capacity Degradation in Low Earth Orbit CubeSat
           Space Applications

    • Authors: Riley Cook, Lukas Swan, Kevin Plucknett
      First page: 20
      Abstract: A wide variety of commercial cylindrical lithium-ion batteries are available for use in nanosatellites (CubeSats) that cycle in low Earth orbit (LEO). This space application differs greatly from the conditions used to create the manufacturer datasheets that CubeSat teams rely on to screen cell types and estimate performance lifetimes. To address this, we experimentally test three LIB cell types using a representative LEO CubeSat power profile in three progressively complex test representations of LEO. The first is “standardized” condition (101 kPa-abs, 20 °C), which uses only a power cycler; the second adds a thermal chamber for “low temperature” condition (101 kPa-abs, 10 °C); and the third adds a vacuum chamber for “LEO” condition (0.2 kPa-abs, 10 °C). Results indicate that general “standardized” and “low temperature” conditions do not yield representative results to what would occur in LEO. Coincidentally, the “LEO” condition gives similar capacity degradation results as manufacturer datasheets. This was an unexpected finding, but suggests that CubeSat teams use full experimental thermal-vacuum testing or default to the manufacturer datasheet performance estimates during the lithium-ion cell screening and selection process. The use of a partial representation of the LEO condition is not recommended.
      Citation: Batteries
      PubDate: 2021-03-15
      DOI: 10.3390/batteries7010020
      Issue No: Vol. 7, No. 1 (2021)
       
 
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