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  Subjects -> ENGINEERING (Total: 2265 journals)
    - CHEMICAL ENGINEERING (188 journals)
    - CIVIL ENGINEERING (179 journals)
    - ELECTRICAL ENGINEERING (99 journals)
    - ENGINEERING (1210 journals)
    - ENGINEERING MECHANICS AND MATERIALS (384 journals)
    - HYDRAULIC ENGINEERING (55 journals)
    - INDUSTRIAL ENGINEERING (60 journals)
    - MECHANICAL ENGINEERING (90 journals)

ENGINEERING (1210 journals)            First | 1 2 3 4 5 6 7 | Last

Showing 1001 - 1200 of 1205 Journals sorted alphabetically
Production and Operations Management     Hybrid Journal   (Followers: 9)
Production Engineering     Hybrid Journal   (Followers: 3)
Production Planning & Control: The Management of Operations     Hybrid Journal   (Followers: 7)
Progress in Agricultural Engineering Sciences     Full-text available via subscription  
Progress in Computational Fluid Dynamics, An International Journal     Hybrid Journal   (Followers: 7)
Progress in Energy and Combustion Science     Full-text available via subscription   (Followers: 8)
Progress in Nanotechnology and Nanomaterials     Open Access   (Followers: 4)
Progress in Photovoltaics: Research & Applications     Hybrid Journal   (Followers: 6)
Progress in Polymer Science     Full-text available via subscription   (Followers: 32)
Propellants, Explosives, Pyrotechnics     Hybrid Journal   (Followers: 238)
Propulsion and Power Research     Open Access   (Followers: 16)
Purinergic Signalling     Hybrid Journal   (Followers: 1)
Quaderns d’Història de l’Enginyeria     Open Access  
Quality and Reliability Engineering International     Hybrid Journal   (Followers: 11)
Quality Engineering     Hybrid Journal   (Followers: 8)
Radiochimica Acta     Hybrid Journal   (Followers: 5)
Rapid Prototyping Journal     Hybrid Journal   (Followers: 3)
Rare Metals     Hybrid Journal  
Reactive and Functional Polymers     Hybrid Journal   (Followers: 5)
Recent Patents on Engineering     Full-text available via subscription   (Followers: 3)
Recent Patents on Nanotechnology     Full-text available via subscription   (Followers: 2)
Recherche Transports Sécurité     Hybrid Journal   (Followers: 1)
Redes de Ingeniería     Open Access  
Regional Maritime University Journal     Full-text available via subscription   (Followers: 1)
Regular and Chaotic Dynamics     Hybrid Journal  
Rem : Revista Escola de Minas     Open Access   (Followers: 1)
Remote Sensing     Open Access   (Followers: 22)
Remote Sensing Letters     Hybrid Journal   (Followers: 25)
Requirements Engineering     Hybrid Journal   (Followers: 3)
Research Ideas and Outcomes     Open Access  
Research in Engineering Design     Hybrid Journal   (Followers: 10)
Research Journal of Nanoscience and Nanotechnology     Open Access   (Followers: 2)
Research Works of Air Force Institute of Technology     Open Access   (Followers: 1)
Resonance     Hybrid Journal   (Followers: 23)
Review of Symbolic Logic     Full-text available via subscription   (Followers: 1)
Reviews in Advanced Sciences and Engineering     Partially Free   (Followers: 2)
Revista AIDIS de Ingeniería y Ciencias Ambientales. Investigación, desarrollo y práctica     Open Access  
Revista Brasileira de Engenharia Agrícola e Ambiental     Open Access   (Followers: 1)
Revista Ciencias e Ingeniería al Día     Open Access  
Revista Científica e-Locução     Open Access  
Revista CINTEX     Open Access  
Revista Cubana de Ingeniería     Open Access  
Revista de Engenharia da Universidade Católica de Petrópolis     Open Access  
Revista de Ingeniería     Open Access  
Revista de Ingenieria Sismica     Open Access  
Revista de Investigación, Desarrollo e Innovación     Open Access  
Revista EIA     Open Access   (Followers: 1)
Revista Facultad de Ingeniería     Open Access   (Followers: 1)
Revista Facultad de Ingenieria - Universidad de Tarapaca     Open Access  
Revista Facultad de Ingeniería Universidad de Antioquia     Open Access   (Followers: 1)
Revista Iberoamericana de Automática e Informática Industrial RIAI     Open Access  
Revista Informador Técnico     Open Access   (Followers: 1)
Revista Ingenieria de Construcción     Open Access  
Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería     Open Access  
Revista Logos Ciencia & Tecnología     Open Access  
Revista Petra     Open Access  
Revue de Métallurgie     Full-text available via subscription  
Russian Engineering Research     Hybrid Journal  
Russian Journal of Non-Ferrous Metals     Hybrid Journal   (Followers: 25)
Russian Microelectronics     Hybrid Journal   (Followers: 1)
Sadhana     Open Access   (Followers: 6)
Safety Science     Hybrid Journal   (Followers: 18)
Scholedge International Journal of Multidisciplinary & Allied Studies     Open Access   (Followers: 2)
Science & Technique     Open Access  
Science and Engineering Ethics     Hybrid Journal   (Followers: 6)
Science and Technology     Open Access   (Followers: 2)
Science China Technological Sciences     Hybrid Journal  
Science in Context     Hybrid Journal   (Followers: 1)
Science Journal of Volgograd State University. Technology and innovations     Open Access  
Science Progress     Full-text available via subscription   (Followers: 3)
Scientia cum Industria     Open Access  
Scientific Journal of Control Engineering     Open Access   (Followers: 1)
Scientific Journal of Pure and Applied Sciences     Open Access   (Followers: 1)
Scientific Journal of Review     Open Access  
Sealing Technology     Full-text available via subscription   (Followers: 1)
Securitas Vialis     Hybrid Journal  
Security and Communication Networks     Hybrid Journal   (Followers: 2)
Selcuk University Journal of Engineering, Science and Technology     Open Access   (Followers: 1)
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of     Hybrid Journal   (Followers: 30)
Semiconductors     Hybrid Journal  
Semiconductors and Semimetals     Full-text available via subscription  
Sensing and Imaging : An International Journal     Hybrid Journal   (Followers: 1)
Sensor Letters     Full-text available via subscription   (Followers: 1)
Sensors     Open Access   (Followers: 12)
Separation and Purification Technology     Hybrid Journal   (Followers: 10)
Services Computing, IEEE Transactions on     Hybrid Journal   (Followers: 4)
Shock and Vibration     Hybrid Journal   (Followers: 6)
SIAM Journal on Applied Dynamical Systems     Hybrid Journal   (Followers: 2)
SIAM Journal on Mathematical Analysis     Hybrid Journal   (Followers: 3)
SIAM Journal on Matrix Analysis and Applications     Hybrid Journal   (Followers: 1)
SIAM Journal on Numerical Analysis     Hybrid Journal   (Followers: 4)
SIAM Journal on Optimization     Hybrid Journal   (Followers: 7)
SIAM Review     Hybrid Journal   (Followers: 6)
SILICON     Hybrid Journal  
Sistemas & Telemática     Open Access   (Followers: 1)
Sleep and Biological Rhythms     Hybrid Journal   (Followers: 4)
Small     Hybrid Journal   (Followers: 10)
Smart Grid     Open Access  
Soft Computing     Hybrid Journal   (Followers: 6)
Software Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 34)
Soil Dynamics and Earthquake Engineering     Hybrid Journal   (Followers: 11)
Soldagem & Inspeção     Open Access  
Solid-State Circuits Magazine, IEEE     Hybrid Journal   (Followers: 9)
SourceOCDE Developpement urbain, rural et regional     Full-text available via subscription   (Followers: 1)
SourceOCDE Energie     Full-text available via subscription  
SourceOECD Energy     Full-text available via subscription  
SourceOECD Science and Technology Statistics - SourceOCDE Base de donnees des sciences et de la technologie     Full-text available via subscription  
SourceOECD Transport     Full-text available via subscription   (Followers: 3)
SourceOECD Urban, Rural and Regional Development     Full-text available via subscription   (Followers: 1)
South African Computer Journal     Full-text available via subscription  
South African Journal of Agricultural Extension     Open Access   (Followers: 3)
South African Journal of Science     Open Access   (Followers: 3)
Sports Engineering     Hybrid Journal   (Followers: 2)
Stahlbau     Hybrid Journal   (Followers: 4)
Steel in Translation     Hybrid Journal  
Steel Research International     Hybrid Journal   (Followers: 27)
Stochastic Analysis and Applications     Hybrid Journal   (Followers: 1)
Stochastic Processes and their Applications     Hybrid Journal   (Followers: 5)
Stochastics and Dynamics     Hybrid Journal  
Strain     Hybrid Journal   (Followers: 1)
Strategic Planning for Energy and the Environment     Hybrid Journal   (Followers: 4)
Studies in Engineering and Technology     Open Access  
Studies in Interface Science     Full-text available via subscription   (Followers: 1)
Studies in Logic and Practical Reasoning     Full-text available via subscription  
Studies in Surface Science and Catalysis     Full-text available via subscription   (Followers: 1)
Superconductor Science and Technology     Hybrid Journal   (Followers: 1)
Surface Engineering     Hybrid Journal   (Followers: 3)
Surface Review and Letters     Hybrid Journal   (Followers: 1)
Surface Science Reports     Full-text available via subscription   (Followers: 15)
Survey Review     Hybrid Journal   (Followers: 6)
Surveying and Land Information Science     Full-text available via subscription   (Followers: 2)
Sustainability Science     Hybrid Journal   (Followers: 6)
Sustainability Science and Engineering     Full-text available via subscription   (Followers: 4)
Sustainable Management of Sediment Resources     Full-text available via subscription  
Swiss Journal of Geosciences     Hybrid Journal  
Symmetry     Open Access  
Synthesis Lectures on Algorithms and Software in Engineering     Full-text available via subscription  
Synthesis Lectures on Antennas     Full-text available via subscription   (Followers: 3)
Synthesis Lectures on Biomedical Engineering     Full-text available via subscription  
Synthesis Lectures on Computational Electromagnetics     Full-text available via subscription   (Followers: 3)
Synthesis Lectures on Energy and the Environment: Technology, Science, and Society     Full-text available via subscription   (Followers: 2)
Synthesis Lectures on Engineering     Full-text available via subscription  
Synthesis Lectures on Global Engineering     Full-text available via subscription  
Synthesis Lectures on Professionalism and Career Advancement for Scientists and Engineers     Full-text available via subscription  
Synthetic Metals     Hybrid Journal   (Followers: 4)
Systems Engineering     Hybrid Journal   (Followers: 6)
Systems Engineering Procedia     Open Access  
Systems Research Forum     Hybrid Journal  
Systems Science & Control Engineering     Open Access   (Followers: 3)
Techno.Com     Open Access  
Technological Engineering     Open Access  
Technologies     Open Access   (Followers: 1)
TECHNOLOGY     Hybrid Journal  
Technology and Innovation     Full-text available via subscription   (Followers: 3)
Technology in Society     Hybrid Journal   (Followers: 4)
Technometrics     Full-text available via subscription   (Followers: 6)
Tecnologia, Ciencia, Educacion     Open Access   (Followers: 1)
Tecnura     Open Access  
Telecommunications Policy     Hybrid Journal   (Followers: 11)
Terahertz Science and Technology, IEEE Transactions on     Hybrid Journal   (Followers: 2)
Textile Science and Technology     Full-text available via subscription   (Followers: 3)
The Journal of Computational Multiphase Flows     Full-text available via subscription  
The Journal of Supercomputing     Hybrid Journal   (Followers: 1)
The Scientific World Journal     Open Access  
Theoretical and Computational Fluid Dynamics     Hybrid Journal   (Followers: 11)
Theoretical Issues in Ergonomics Science     Hybrid Journal   (Followers: 2)
Thermal Engineering     Hybrid Journal   (Followers: 4)
Tikrit Journal of Engineering Science     Open Access  
tm - Technisches Messen     Hybrid Journal   (Followers: 1)
Topics in Catalysis     Hybrid Journal   (Followers: 1)
Traffic Injury Prevention     Hybrid Journal   (Followers: 48)
TRANSACTIONS of the VŠB - Technical University of Ostrava, Safety Engineering Series     Open Access   (Followers: 1)
Transactions of Tianjin University     Full-text available via subscription  
Transport and Telecommunication Journal     Open Access   (Followers: 3)
Transport World Africa     Full-text available via subscription   (Followers: 3)
Transportation Research Record : Journal of the Transportation Research Board     Full-text available via subscription   (Followers: 33)
Transportmetrica A : Transport Science     Hybrid Journal   (Followers: 5)
Trends in Applied Sciences Research     Open Access   (Followers: 1)
Tribology in Industry     Open Access   (Followers: 1)
Tribology International     Hybrid Journal   (Followers: 41)
Tribology Letters     Hybrid Journal   (Followers: 5)
Tribology Transactions     Hybrid Journal   (Followers: 33)
Tribotest     Hybrid Journal  
Tropical Science     Hybrid Journal   (Followers: 1)
Turkish Journal of Engineering and Environmental Sciences     Open Access   (Followers: 1)
Ultramicroscopy     Hybrid Journal   (Followers: 2)
Uludağ University Journal of The Faculty of Engineering     Open Access  
Universal Journal of Applied Science     Open Access   (Followers: 2)
Universal Journal of Engineering Science     Open Access   (Followers: 1)
Utilities Policy     Hybrid Journal   (Followers: 2)
Vacuum     Hybrid Journal   (Followers: 12)
Virtual and Physical Prototyping     Hybrid Journal   (Followers: 3)
Visualization in Engineering     Open Access  
Walailak Journal of Science and Technology     Open Access  
Waste and Biomass Valorization     Hybrid Journal  
Waste Management Series     Full-text available via subscription   (Followers: 2)
Waves in Random and Complex Media     Hybrid Journal  
Waves, Wavelets and Fractals     Open Access  
Wear     Hybrid Journal   (Followers: 29)
Welding in the World     Hybrid Journal   (Followers: 2)

  First | 1 2 3 4 5 6 7 | Last

Journal Cover Ionics
  [SJR: 0.497]   [H-I: 27]   [0 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1862-0760 - ISSN (Online) 0947-7047
   Published by Springer-Verlag Homepage  [2335 journals]
  • Improvement of electrochemical performance for AlF 3 -coated Li 1.3 Mn 4/6
           Ni 1/6 Co 1/6 O 2.40 cathode materials for Li-ion batteries
    • Abstract: Abstract Li-rich layered-layered-Spinel structure spherical Li1.3Mn4/6Ni1/6Co1/6O2.40 particles was successfully prepared and coated with a uniform layer by a two-step co-precipitation method and evaluated in lithium cells. The structures and electrochemical properties of pristine Li1.3Mn4/6Ni1/6Co1/6O2.40 and AlF3-coated Li1.3Mn4/6Ni1/6Co1/6O2.40 were characterized. When the coating amount was 2 wt%, the cathode showed the best cycling performance and rate capability compared to others. The AlF3-coated Li1.3Mn4/6Ni1/6Co1/6O2.40 Li-ion cell cathode had a capacity retention of 90.07 % after 50 cycles at 0.5 C over 2.0–4.8 V, while the pristine Li1.3Mn4/6Ni1/6Co1/6O2.40 exhibited capacity retention of only 80.73 %. Moreover, the rate capability and cyclic performance also improved. Electrochemical impedance spectroscopy testing revealed that the improved electrochemical performance might attribute to the AlF3 coating layer which can suppress the increase of impedance during the charging and discharging process by preventing direct contact between the highly delithiated active material and electrolyte.
      PubDate: 2016-08-01
       
  • The electrochemical behavior of Dy(III) in eutectic LiF-DyF 3 at W
           electrode
    • Abstract: Abstract The electrochemical reduction process of Dy ion on tungsten electrode at 1103 K in Dy2O3-LiF-DyF3 molten system was studied by cyclic voltammetry, chronoamperometry, and chronopotentiometry methods with a three-electrode system on the electrochemical workstation AUTOLAB. The results showed that Dy3+ could be deposited at around −0.75 V on inert W electrode compared with platinum electrode. The reduction process of Dy ion on W electrode occurred in a single step with the exchange of three electrons because one reduction peak was observed, and the calculated transfer electron number was three. Chronoamperograms indicated that the nucleation process of dysprosium ions was instantaneous three-dimensional nucleation on a tungsten electrode. The cathode electrochemical process on the tungsten electrode was controlled by the diffusion of ions, and the diffusion coefficient was 1.159 × 10−4 cm2/s, which was calculated from a chronopotentiogram.
      PubDate: 2016-08-01
       
  • Single crystalline 3C-SiC whiskers used for electrochemical detection of
           nitrite under neutral condition
    • Abstract: Abstract A new kind of nitrite sensor based on 3C-SiC whisker electrode was fabricated to electrochemically determine nitrite. Powder X-ray diffraction, field emission scanning electron microscope, and transmission electron microscopy reveal SiC whiskers are cubic single crystalline with some microtwins. The prepared SiC whisker electrode is examined for the electrochemical detection of nitrite under neutral condition using cyclic voltammetry and differential pulse voltammetry techniques. The results demonstrate that SiC whisker electrode fast responses toward nitrite with a detection limit of 3.5 × 10−6 mol L−1, which is comparable to the values reported in the recent literatures. The synthesized electrode is also successfully applied to determine nitrite in tap water.
      PubDate: 2016-08-01
       
  • Synthesis of spinel LiNi 0.5 Mn 1.5 O 4 as advanced cathode via a modified
           oxalate co-precipitation method
    • Abstract: Abstract Spinel-type LiNi0.5Mn1.5O4 (LNMO) cathode materials for lithium ion batteries have been synthesized via a modified oxalate co-precipitation method. By virtue of the co-precipitation of Li+ with transition metal ions, the target materials can be obtained through one-pot reaction without subsequent mixing with lithium salts. What’s more, a uniform distribution between the lithium and transition metal ions at molecular level could be realized, which is beneficial for final electrochemical performances. The physical and electrochemical properties of the material are characterized by XRD, TGA, EDS, FT-IR, SEM, CV, EIS, and charge/discharge tests. The results prove that the as-prepared material owns a cubic spinel structure with a space group of Fd-3m, high crystallinity, uniform particle size, and excellent electrochemical performances. A higher initial capacity and superior rate performance are delivered compared with that of material by conventional co-precipitation method. High capacities of 131.7 and 104.0 mAh g−1 could be displayed at 0.5 and 10 C, respectively. Excellent cycle stability is also demonstrated with more than 98.5 % capacity retention after 100 cycles at 1 C.
      PubDate: 2016-08-01
       
  • A novel nitroxide radical polymer-containing conductive polyaniline as
           molecular skeleton: its synthesis and electrochemical properties as
           organic cathode
    • Abstract: Abstract A novel nitroxide radical-containing aniline, 4-(6-(2-amino-phenol-9H-yl)hexanoyloxy)-2,2,6,6-tetramethylpiperidin-1-yloxy (AnT), was synthesized, and the copolymers of AnT and aniline (P (An-co-AnT)) were then prepared by chemical oxidative polymerization. The introduction of polyaniline (PAn) skeleton in copolymers improved the charge migration along polymer backbone, and the increased ratio of An/AnT monomer makes PAn’s anodic peak in copolymers shift to negative potential and the redox peaks for the nitroxide radical shift to the positive potential. Also, P (An-co-AnT) exhibited a gradually increased charged specific capacity from 120.1 to 141.0 mAh g−1 with increasing the feeding ratio of AnT/An, while the discharge specific capacity presented an opposite result. Specially, P (An-co-AnT) exhibited an obvious charge voltage platform and an even improved cycling stability than that of PAn in the high feeding ratio of AnT/An, and after 20 cycles, the discharge capacity of P (An-co-AnT) (1:1 ([An]/[AnT])) still maintained 82.7 % of the capacity obtained at the initial cycle.
      PubDate: 2016-08-01
       
  • Improvement in rate capability of lithium-rich cathode material Li[Li 0.2
           Ni 0.13 Co 0.13 Mn 0.54 ]O 2 by Mo substitution
    • Abstract: Abstract Lithium-rich cathode material Li[Li0.2Ni0.13Co0.13Mn0.54]O2 doped with trace Mo is successfully synthesized by a sol-gel method. The X-ray diffraction patterns show that trace Mo substitution increases the inter-layer space of the material, of which is benefiting to lithium ion insertion/extraction among the electrode materials. The (CV) tests demonstrate the decrease of polarization, and on the other hand, the lithium ion diffusion coefficient (D Li) of the modified material turns out to be larger, which indicates a faster electrochemical process. As a result, the Mo doped material possesses high rate performance and good cycling stability, and the initial discharge capacity reaches 149.3 mAh g−1 at a current density of 5.0 °C, and the residual capacity is 144.0 mAh g−1 after 50 cycles with capacity retention of 96.5 % in the potential range of 2.0–4.8 V at room temperature.
      PubDate: 2016-08-01
       
  • Effect of 10 MeV energy of electron irradiation on Fe 2+ doped ZnSe
           nanorods and their modified properties
    • Abstract: Abstract The Fe2+-doped ZnSe nanorods are synthesized using simple potentiostatic mode of electrodeposition on the tin-doped indium oxide (ITO) substrate. To study the effect of electron irradiation, the 10-MeV energy has been applied on 1 % Fe2+-doped ZnSe nanorods with different doses such as 10, 20 and 30 kGy. After electron irradiation, structural, morphological, optical, electrochemical and photoelectrochemical properties have been investigated. Due to high energy electron irradiation dose, drastic changes have been observed in the morphological properties; hence, changes have been observed in photoelectrochemical properties also. Due to high-energy, nanorods are destroyed and the photoelectrochemical cell performance (PEC) has been decreased.
      PubDate: 2016-08-01
       
  • Facile fabrication of manganese phosphate nanosheets for supercapacitor
           applications
    • Abstract: Abstract Manganese phosphate (Mn3(PO4)2·3H2O) nanosheets are successfully fabricated via a facile chemical precipitation method. The Mn3(PO4)2·3H2O nanosheets synthesized at 70 °C show excellent supercapacitive performance in 2 M KOH alkaline electrolyte. Typical pseudocapacitance feature of Mn3(PO4)2·3H2O nanosheets treated at various annealing temperatures is then evaluated in 2 M KOH alkaline electrolyte. M3 annealed at 750 °C exhibits the optimal integrated electrochemical properties. Furthermore, an asymmetric supercapacitor composed of M3 as positive electrode and activated carbon (AC) as negative electrode can reach the high-voltage region of 0–1.7 V. The asymmetric supercapacitor displays high energy density of 32.32 Wh kg−1 and power density of 4250 W kg−1. The impressive results presented here may pave the way for promising applications in high energy density storage systems.
      PubDate: 2016-08-01
       
  • Effect of microstructure on chemical stability and electrical properties
           of BaCe 0.9 Y 0.1 O 3 − δ
    • Abstract: Abstract Y-doped barium cerate BaCe0.9Y0.1O3 − δ was synthesised by a solid-state reaction method. Materials with different average grain sizes and grain boundary surface areas were obtained. The effect of microstructure on the chemical stability in the CO2 and H2O-containing atmosphere and electrical properties was analysed and discussed. To evaluate the chemical stability of BaCe0.9Y0.1O3 − δ , the exposure test was performed. Samples were exposed to the carbon dioxide and water vapour-rich atmosphere at 25 °C for 700 h. Thermogravimetry supplied by mass spectrometry was applied to analyse the samples before and after this comprehensive test. The mass loss for samples before and after the test and the amount of BaCO3 formed during the test were directly treated as the measure of chemical instability of BaCe0.9Y0.1O3 − δ in the atmosphere rich in carbon dioxide and water vapour. As it was observed, the BaCe0.9Y0.1O3 − δ chemical stability towards CO2 and H2O is not affected by the materials’ microstructure. Electrical properties of BaCe0.9Y0.1O3 − δ which differs with microstructure were determined using electrochemical impedance spectroscopy (EIS). It was found that the grain interior resistivity and activation energy of grain interior conductivity is microstructure independent. However, the effect on microstructure was seen on the EIS spectra in the range of grain boundary contribution. Therefore, the lowest activation energy and the highest conductivity were observed for a material with the lowest grain boundary surface area.
      PubDate: 2016-08-01
       
  • Synthesis and performance of nickel hydroxide nanodiscs for redox
           supercapacitors
    • Abstract: Abstract Herein, we report the facile synthesis of β-Ni(OH)2 nanodiscs by chemical precipitation method and their use in supercapacitors. β-Ni(OH)2 nanodiscs are characterized by FTIR, XRD, FESEM, XPS and TGA analysis. Morphological analysis revealed the uniform nanodisc morphology of β-Ni(OH)2. The supercapacitor behavior is evaluated by cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy measurements in 1-M aqueous KOH solution with 0- to 0.6-V potential window. The specific capacitance of β-Ni(OH)2 nanodiscs is found to be 400 F g−1. The energy and power densities of the β-Ni(OH)2 nanodiscs are found to be 7.15 W h kg−1 and 1716 W kg−1, respectively, at the current density of 1 A g−1. The cycle life test shows the good stability of the electrode with 83 % retention capacitance even after 1500 cycles.
      PubDate: 2016-08-01
       
  • Nanoplate-like CuO: hydrothermal synthesis, characterization, and
           electrochemical properties
    • Abstract: Abstract Plate-like nanocrystalline CuO was synthesized via the hydrothermal process using copper nitrate trihydrate as inorganic precursor and 1,3-diaminoprapane which acts as a structure-directing template. The morphology, the structure, the crystallinity and the composition were studied through x-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). It was found that the hydrothermal reaction time had a marked effect on the morphology and particularly, on the particle size and the nature of the resulting products. The optical properties of the as-synthesized CuO nanoplatelets were studied by UV-visible diffuse reflectance spectra (DRS) and the values of the band were found to be 1.93 eV. Electrochemical measurements have revealed a reversible redox behavior with a doping/de-doping process corresponding to reversible cation intercalation/de-intercalation. This process is easier for the smaller sized Li+ cation compared to the larger Na+ cation and to the largest K+ cation.
      PubDate: 2016-08-01
       
  • Preparation of carbon composite from coconut fiber for gas diffusion layer
    • Abstract: Abstract A natural carbon from coconut fiber is used as a main composite material of gas diffusion layer (GDL) for fuel cell electrode. The composite comprise of polymer (ethylene vinyl acetate and poly ethylene glycol) and carbon in various compositions. The materials are mixed in xylene and printed using casting method. The composite is coated with polytetrafluoro ethylene (PTFE) to achieve hydrophobic requirement as GDL. The electrical properties of composite were measured by using LCR-meter, the porosity was obtained by immersion method, and the hydrophobic properties were observed by measuring its contact angle. The results show the electrical conductivity of GDL prepared corresponds to its carbon content. The electrical conductivity of GDLs is 22.17, 26.89, 35, 43, and 52 S/m for the carbon composition of 65, 70, 75, 80, and 85 %, respectively. The composite of 80 % carbon content and coated with PTFE contains 74 % porosity and has desired hydrophobic properties revealed from its high contact angle, i.e., 120°.
      PubDate: 2016-08-01
       
  • Enhanced electrochemical performances of layered LiNi 0.5 Mn 0.5 O 2 as
           cathode materials by Ru doping for lithium-ion batteries
    • Abstract: Abstract The pristine and Ru-doped LiNi0.5Mn0.5O2 cathode materials are synthesized by a wet chemical method, followed by a high-temperature calcination process. The influence of Ru substitution on the microstructure and electrochemical performances of the prepared materials are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and galvanostatic charge/discharge test. The XRD results show that, compared to the Ru-undoped sample, the LiNi0.5Mn0.45Ru0.05O2 owns a better hexagonal α-NaFeO2 structure and a smaller amount of cation mixing. The galvanostatic charge/discharge measurements demonstrate that the electrochemical properties of the LiNi0.5Mn0.5O2 sample are enhanced by Ru doping. At 5 and 10 C, the discharge capacity of LiNi0.5Mn0.45Ru0.05O2 is 118.61 and 105.43 mAh g−1, respectively, which is higher than those of LiNi0.5Mn0.5O2 (101.24 and 78.94 mAh g−1) due to the reduced charge-transfer resistance and the improved lithium-ion diffusion coefficient. On the basis of these results, Ru doping is considered an effective way to enhance the electrochemical performances of LiNi0.5Mn0.5O2 cathode materials.
      PubDate: 2016-08-01
       
  • Studies on kinetics and thermodynamics of ion adsorption reactions by
           applications of short-lived radioactive tracer isotopes
    • Abstract: Abstract The short-lived radiotracer isotopes were applied to study the kinetics and thermodynamic feasibility of iodide as well as bromide ion adsorption reactions using industrial-grade resin materials. Free energy of activation (ΔG ‡) and energy of activation (E a) were calculated by using Arrhenius equation, enthalpy of activation (ΔH ‡), and entropy of activation (ΔS ‡) calculated by using the Eyring-Polanyi equation. These parameters were used to predict the thermodynamic feasibility of the two ion adsorption reactions performed by using Dowex SBR LC and Indion-810 resins. It was observed that during iodide ion adsorption reactions, the values of energy of activation (−18.79 kJ mol−1), enthalpy of activation (−21.37 kJ mol−1), free energy of activation (58.13 kJ mol−1), and entropy of activation (−0.26 kJ K−1 mol−1) calculated for Indion-810 resins were lower than the respective values of −4.28 kJ mol−1, −6.87 kJ mol−1, 64.97 kJ mol−1, and −0.23 kJ K−1 mol−1 calculated for Dowex SBR LC under similar experimental conditions. Identical trends were observed for the two resins during bromide ion adsorption reactions. The low values of different thermodynamic parameters obtained for Indion-810 resins during both the ion adsorption reactions indicate that the reactions are thermodynamically more feasible using Indion-810 resins as compared to Dowex SBR LC resins. It is expected here that the present nondestructive technique can be extended further for different ions in the solution in order to predict the thermodynamic feasibility of different ion adsorption reactions for the range of resins which are widely used for treatment of industrial waste water effluent.
      PubDate: 2016-08-01
       
  • Improved performance of cobalt-based spinel by the simple solvothermal
           method as electrocatalyst for oxygen reduction reaction in alkaline
           solution
    • Abstract: Abstract The performance of the cobalt-based spinel electrocatalysts (MCo2X4) is improved for oxygen reduction reaction (ORR) by simply optimizing solvothermal conditions via the orthogonal experiment L18 (2 × 37). Five conditions are investigated, and the order of significant factors for ORR efficiency is metal component > solvothermal temperature > calcining temperature > precipitant > solvent component. Mn, Ni, or S is considered as the factor of metal component or precipitant respectively and is introduced into the Co3O4 to find the best MCo2X4 for ORR. But, the pure Co3O4 exhibits the best performance among these cobalt-based catalysts. The optimized product, 9.6 wt.% Co3O4 supported on carbon (Co3O4/C), can reach 90 % of the 20 wt.% Pt/C in term of the limited diffusion current exhibiting the close efficiency of Co3O4/C to Pt/C. Methanol-poisoning tests performed by chronoamperometry show the Co3O4/C remained 95 % current after 6 h, exhibiting superior methanol resistance and long-time stability.
      PubDate: 2016-08-01
       
  • ZnO-coated LiMn 2 O 4 cathode material for lithium-ion batteries
           synthesized by a combustion method
    • Abstract: Abstract ZnO-coated LiMn2O4 cathode materials were prepared by a combustion method using glucose as fuel. The phase structures, size of particles, morphology, and electrochemical performance of pristine and ZnO-coated LiMn2O4 powders are studied in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), galvanostatic charge-discharge test, and X-ray photoelectron spectroscopy (XPS). XRD patterns indicated that surface-modified ZnO have no obvious effect on the bulk structure of the LiMn2O4. TEM and XPS proved ZnO formation on the surface of the LiMn2O4 particles. Galvanostatic charge/discharge test and rate performance showed that the ZnO coating could improve the capacity and cycling performance of LiMn2O4. The 2 wt% ZnO-coated LiMn2O4 sample exhibited an initial discharge capacity of 112.8 mAh g−1 with a capacity retention of 84.1 % after 500 cycles at 0.5 C. Besides, a good rate capability at different current densities from 0.5 to 5.0 C can be acquired. CV and EIS measurements showed that the ZnO coating effectively reduced the impacts of polarization and charge transfer resistance upon cycling.
      PubDate: 2016-08-01
       
  • Investigation on lithium ion conductivity and structural stability of
           yttrium-substituted Li 7 La 3 Zr 2 O 12
    • Abstract: Abstract Advanced Li-air battery architecture demands a high Li+ conductive solid electrolyte membrane that is electrochemically stable against metallic lithium and aqueous electrolyte. In this work, an investigation has been carried out on the microstructure, Li+ conduction behaviour and structural stability of Li7La3-x Y x Zr2O12 (x = 0.125, 0.25 and 0.50) prepared by conventional solid-state reaction technique. The phase analysis of Li7La3-x Y x Zr2O12 (x = 0.125, 0.25 and 0.50) sintered at 1200 °C by powder X-ray diffraction (PXRD) and Raman confirms the formation of high Li+ conductive cubic phase ( \( Ia\overline{3}d \) ) lithium garnets. Among the investigated lithium garnets, Li7La2.75Y0.25Zr2O12 sintered at 1200 °C exhibits a maximized room temperature total (bulk + grain boundary) Li+ conductivity of 3.21 × 10−4 S cm−1 along with improved relative density of 96 %. The preliminary investigation on the structural stability of Li7La2.75Y0.25Zr2O12 in the solutions of 1 M LiCl, dist. H2O and 1 M LiOH at 30 °C/50 °C indicates that the Li7La2.75Y0.25Zr2O12 is relatively stable against 1 M LiCl and dist. H2O. Further electrochemical investigation is essential for practical application of Li7La2.75Y0.25Zr2O12 as protective solid electrolyte membrane in aqueous Li-air battery.
      PubDate: 2016-08-01
       
  • Design of amphiphilic poly(vinylidene fluoride- co
           -hexafluoropropylene)-based gel electrolytes for high-performance
           lithium-ion batteries
    • Abstract: Abstract Gel polymer electrolytes (GPE) based on electrospun polymer membranes, poly(vinylidene fluoride-co-hexafluoropropylene), grafted poly(poly(ethylene glycol) methyl ether methacrylate) (PVDF-HFP-g-PPEGMA), and poly(vinylidene difluoride-co-hexafluoropropylene) (PVDF-HFP) are prepared for lithium ion batteries by incorporating with 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMITFSI). The uniform porosity and the compatibility of blend electrospun membranes avoiding the pore blocking are beneficial to enhance the electrolyte uptakes. The GPE based on the fibrous PVDF-HFP-g-PPEGMA/PVDF-HFP activated with 1 M LiTFSI (BMITFSI) show a maximum ionic conductivity of 2.3 × 10−3 S cm−1 at room temperature and electrochemical stability of up to 5.2 V. The Li/GPE/LiFePO4 cells with GPE based on PVDF-HFP-g-PPEGMA/PVDF-HFP blend electrospun membrane deliver specific capacities of 163, 141, and 125 mAh g−1 at 0.1, 0.5, and 1C rates, respectively, and remains well after 50 cycles for each rate. Therefore, the novel GPE have been demonstrated to be suitable for lithium-ion battery applications.
      PubDate: 2016-08-01
       
  • Synthesis and electrochemical investigation of highly dispersed ZnO
           nanoparticles as anode material for lithium-ion batteries
    • Abstract: Abstract Highly dispersed ZnO nanoparticles were prepared by a versatile and scalable sol-gel synthetic technique. High-resolution transmission electronic microscopy (HRTEM) showed that the as-prepared ZnO nanoparticles are spherical in shape and exhibit a uniform particle size distribution with the average size of about 7 nm. Electrochemical properties of the resulting ZnO were evaluated by galvanostatic discharge/charge cycling as anode for lithium-ion battery. A reversible capacity of 1652 mAh g−1 was delivered at the initial cycle and a capacity of 318 mAh g−1 was remained after 100 cycles. Furthermore, the system could deliver a reversible capacity of 229 mAh g−1 even at a high current density of 1.5 C. This outstanding electrochemical performance could be attributed to the nano-sized features of highly dispersed ZnO particles allowing for the better accommodation of large strains caused by particle expansion/shrinkage along with providing shorter diffusion paths for Li+ ions upon insertion/deinsertion.
      PubDate: 2016-08-01
       
  • Characterization of blend polymer PVA-PVP complexed with ammonium
           thiocyanate
    • Abstract: Abstract Thin films of blend polymer electrolytes comprising poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) complexed with ammonium thiocyanate (NH4SCN) salt in different compositions have been prepared by solution casting technique using distilled water as solvent. The prepared films have been investigated by different experimental techniques. The complexation of these films has been studied by FTIR spectroscopy. The increase in amorphousness of the films with increase in NH4SCN content has been confirmed by XRD analysis. The addition of ammonium thiocyanate salt to PVA-PVP polymer blend shows a shift in Tg of the blend. The effect of salt concentration and temperature on the ionic conductivity of the polymer blend films has been analyzed using AC impedance spectroscopy. The maximum conductivity of 6.85 × 10−4 S cm−1 at room temperature has been observed for the blend with 50 mol% PVA-50 mol% PVP complexed with 40 mol% NH4SCN. The activation energy has been found to be minimum (0.24 eV) for this sample. Wagner’s polarization technique shows that the charge transport in these blend films is predominantly due to ions. Using the highest conductivity blend polymer electrolyte, a proton battery has been fabricated and its discharge characteristics have been studied.
      PubDate: 2016-08-01
       
 
 
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