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  Subjects -> ENGINEERING (Total: 2246 journals)
    - CHEMICAL ENGINEERING (187 journals)
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ENGINEERING (1206 journals)            First | 1 2 3 4 5 6 7 | Last

Showing 1001 - 1200 of 1205 Journals sorted alphabetically
Production     Open Access  
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: 6)
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: 7)
Progress in Polymer Science     Full-text available via subscription   (Followers: 32)
Propellants, Explosives, Pyrotechnics     Hybrid Journal   (Followers: 218)
Propulsion and Power Research     Open Access   (Followers: 13)
Purinergic Signalling     Hybrid Journal  
Quaderns d’Història de l’Enginyeria     Open Access  
Quality and Reliability Engineering International     Hybrid Journal   (Followers: 11)
Quality Engineering     Hybrid Journal   (Followers: 7)
Radiochimica Acta     Hybrid Journal   (Followers: 4)
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: 2)
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: 14)
Remote Sensing Letters     Hybrid Journal   (Followers: 12)
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: 16)
Review of Symbolic Logic     Full-text available via subscription   (Followers: 1)
Reviews in Advanced Sciences and Engineering     Partially Free   (Followers: 1)
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 Informador Técnico     Open Access   (Followers: 1)
Revista Ingenieria de Construcción     Open Access  
Revista Logos Ciencia & Tecnología     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  
Sadhana     Open Access   (Followers: 4)
Safety Science     Hybrid Journal   (Followers: 16)
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  
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)
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of     Hybrid Journal   (Followers: 17)
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: 9)
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     Full-text available via subscription   (Followers: 2)
SIAM Journal on Mathematical Analysis     Full-text available via subscription   (Followers: 3)
SIAM Journal on Matrix Analysis and Applications     Full-text available via subscription   (Followers: 1)
SIAM Journal on Numerical Analysis     Full-text available via subscription   (Followers: 4)
SIAM Journal on Optimization     Full-text available via subscription   (Followers: 6)
SIAM Review     Full-text available via subscription   (Followers: 5)
SILICON     Hybrid Journal  
Sistemas & Telemática     Open Access   (Followers: 1)
Sleep and Biological Rhythms     Hybrid Journal   (Followers: 3)
Small     Hybrid Journal   (Followers: 8)
Smart Grid     Open Access  
Soft Computing     Hybrid Journal   (Followers: 6)
Software Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 33)
Soil Dynamics and Earthquake Engineering     Hybrid Journal   (Followers: 8)
Soldagem & Inspeção     Open Access  
Solid-State Circuits Magazine, IEEE     Hybrid Journal   (Followers: 7)
SourceOCDE Developpement urbain, rural et regional     Full-text available via subscription  
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: 28)
Stochastic Analysis and Applications     Hybrid Journal  
Stochastic Processes and their Applications     Hybrid Journal   (Followers: 4)
Stochastics and Dynamics     Hybrid Journal  
Strain     Hybrid Journal   (Followers: 1)
Strategic Planning for Energy and the Environment     Hybrid Journal   (Followers: 3)
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  
Surface Engineering     Hybrid Journal   (Followers: 3)
Surface Review and Letters     Hybrid Journal   (Followers: 1)
Surface Science Reports     Full-text available via subscription   (Followers: 14)
Survey Review     Hybrid Journal   (Followers: 6)
Surveying and Land Information Science     Full-text available via subscription   (Followers: 2)
Sustainability Science     Hybrid Journal   (Followers: 5)
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: 4)
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: 8)
Terahertz Science and Technology, IEEE Transactions on     Hybrid Journal   (Followers: 1)
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: 9)
Theoretical Issues in Ergonomics Science     Hybrid Journal   (Followers: 2)
Thermal Engineering     Hybrid Journal   (Followers: 3)
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: 41)
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  
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  
Wear     Hybrid Journal   (Followers: 29)
Welding in the World     Hybrid Journal   (Followers: 2)
West African Journal of Industrial and Academic Research     Open Access   (Followers: 1)
Women in Engineering Magazine, IEEE     Full-text available via subscription   (Followers: 8)
World Journal of Engineering     Full-text available via subscription   (Followers: 3)
World Journal of Engineering and Technology     Open Access  

  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  [2281 journals]
  • Synthesis of high-performance Fe–Mg-co-doped LiMnPO 4 /C via a
           mechano-chemical liquid-phase activation technique
    • Abstract: Abstract Carbon-coated Fe–Mg-homogeneously dispersed Li(Mn0.9Fe0.10)1 − x Mg x PO4/C (x = 0.00, 0.01, 0.03, 0.05, and 0.07) powders are synthesized via a mechano-chemical liquid-phase activation technique. Fine-sized and Fe2+ and Mg2+ evenly distributed precursors are formed using this efficient approach successfully. The synthesis temperature and the Mg2+ doping ratio are investigated and optimized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and electrochemical measurements. Mg doping decreases the lattice parameters of LiMn0.9Fe0.1PO4/C, which will ease the expansion/shrinking effect during the insertion/de-insertion processes. Li(Mn0.9Fe0.1)0.95Mg0.05PO4/C synthesised at 700 °C with ~3 wt% of carbon additive presents the best comprehensive electrochemical properties, and it displays good rate capability with specific discharge capacity of 153 mAh g−1 at 0.1C, 140 mAh g−1 at 1C, and 132 mAh g−1 at 2C rate. The results suggest that the electrochemical performance of the LiMnPO4-based cathode is improved as (Mn0.9Fe0.1) is partially substituted by Mg.
      PubDate: 2016-05-01
  • Preparation and characterization of biodegradable
           poly(ε-caprolactone)-based gel polymer electrolyte films
    • Abstract: Abstract Biodegradable polymer electrolyte films based on poly(ε-caprolactone) (PCL) in conjunction with lithium tetrafluoroborate (LiBF4) salt and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4) ionic liquid were prepared by solution cast technique. The structural, morphological, thermal, and electrical properties of these films were examined using X-ray diffraction (XRD), optical microscopy (OM), differential scanning calorimetry (DSC), and impedance spectroscopy. The XRD and OM results reveal that the pure PCL possesses a semi-crystalline nature and its degree of crystallinity decreases with the addition of LiBF4 salt and EMIMBF4 ionic liquid. DSC analysis indicates that the melting temperature and enthalpy are apparently lower for the 40 wt% EMIMBF4 gel polymer electrolyte as compared with the others. The ambient temperature electrical conductivity increases with increasing EMIMBF4 concentration and reaches a high value of ∼2.83 × 10−4 S cm−1 for the 85 PCL:15 LiBF4 + 40 wt% EMIMBF4 gel polymer electrolyte. The dielectric constant and ionic conductivity follow the same trend with increasing EMIMBF4 concentration. The dominant conducting species in the 40 wt% EMIMBF4 gel polymer electrolyte determined by Wagner’s polarization technique are ions. The ionic conductivity of this polymer electrolyte (∼2.83 × 10−4 S cm−1) should be high enough for practical applications.
      PubDate: 2016-05-01
  • Influence of oxalate anions on manganese electrodeposition in sulfate
    • Abstract: Abstract The influences of oxalate anions on manganese electrodeposition in sulfate solution were investigated on the basis of cathode current efficiency, characterization of SEM-EDX and XRD, solution chemistry calculation, thermodynamics and electrochemical test. The experimental results show that the range of (NH4)2C2O4 was adjusted from 0 mol/L to 4.8 × 10−3 mol/L. And 1.5 × 10−3 mol/L (NH4) 2C2O4 was suitably used with initial pH 7.0. The characterization of SEM indicates that oxalate anions can improve the morphology of electrodeposited films. The electrodeposited films containing manganese were characterized and determined by EDX and XRD. The solution chemistry calculation of catholyte and oxalate anions shows that the main active species are MnSO4, Mn(SO4)2− 2, Mn2+, Mn(SO4)C2O2− 4, MnC2O 4, Mn(NH3)2+, and C2O2− 4. The reaction trend between C2O2− 4 and Mn2+ ions is confirmed by computation of reaction energy. Electrochemical test analysis indicates oxalate anions increase the overpotentials of hydrogen evolution reaction and manganese electrodeposition.
      PubDate: 2016-05-01
  • Development of a perturbed hard-sphere equation of state for pure and
           mixture of ionic liquids
    • Abstract: Abstract A perturbed hard-sphere equation of state (PHS EOS) was previously proposed to present the volumetric properties of ionic liquids by employing a variable parameter β being a function of acentric factor to justify the range of vdW dispersion forces (M. M. Papari, J. Moghadasi, S. M. Hosseini, F. Akbari, J. Mol. Liq. 158 (2011) 57–60). The main aim of the present study is to revise an attractive part of the preceding EOS by re-evaluating the above-mentioned variable parameter as well as the repulsive term. Two temperature-dependent parameters appearing in the revisited EOS have been determined from the corresponding states correlations using the interfacial properties of ILs, i.e., surface tension and liquid density, both at room temperature. The revisited EOS has been employed to model the volumetric properties of ionic liquids (ILs). The predictive power of the proposed model has been assessed by comparing the results obtained with 2189 experimental data points related to 24 ILs over a broad range of pressures and temperatures. The overall average absolute deviation (AAD) of the calculated densities from literature data was found to be 0.62 %. Furthermore, the revisited PHS EOS has been employed to model the volumetric properties of 23 mixtures including IL + IL and IL+ solvent over the vast range of temperatures. From 1580 data points of the binary mixtures of interest, the AAD of the correlated densities from the measurements was found to be 0.47 %.
      PubDate: 2016-05-01
  • Performance of C/C electric double layer capacitors with coal-based active
           carbon electrodes
    • Abstract: Abstract Coal-based active carbon was prepared and used as electrodes of electric double-layer capacitors (EDLCs). The performance of EDLCs using active carbon electrodes with different pore structure was studied, including cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. With an increase of sodium hydrate/coal ratio, the pore structure of active carbon is greatly improved, resulting in larger double-layer capacitance. The capacitance of asymmetric EDLC is up to 65.98 F/g. Moreover, it is found that different pore structure of active carbon is necessary for positive and negative electrodes. Asymmetric EDLC not only exhibits high capacitance but also shows excellent charge-discharge performance, suggesting that it is very suitable and promising to design electrode materials for supercapacitors.
      PubDate: 2016-05-01
  • Rapid and sensitive determination of cobalt by adsorptive cathodic
           stripping voltammetry using tin–bismuth alloy electrode
    • Abstract: Abstract Tin–bismuth alloy electrode (SnBiE) was used for trace cobalt determination for the first time. Compared to the bismuth bulk electrode, the SnBiE possesses the advantages of higher hydrogen overpotential, easier manufacture, and lower cost. In addition, there is no need for a pretreatment (in terms of modification) of the electrode before measurements. The analysis of Co(II) was made by the adsorptive accumulation of the cobalt–nioxime complex from solution containing 60 μM nioxime and 0.1 M ammonia at pH 9.4 and followed by the reduction of the accumulated complex. The electroanalysis results show that the optimal sensitivity can be obtained by using nitrite as the auxiliary reagent. The calibration plot for Co(II) quantification was linear from 0.2 to 20 nM with a correlation coefficient of 0.998. Meanwhile, a detection limit of 44 pM was obtained in connection with an accumulation time of 60 s, which is more sensitive than that of the mercury, bismuth, lead, and lead–copper electrodes. The practical applications of SnBiE have been performed for the determination of Co(II) in real water samples, and the results are consistent with those results by use of inductively coupled plasma–mass spectrometry (ICP-MS).
      PubDate: 2016-05-01
  • On electrochemistry of Al 2 O 3 -coated LiCoO 2 composite cathode with
           improved cycle stability
    • Abstract: Abstract LiCoO2-based cathode does still have a powerful competition in high-end mobile electronics due to its relatively high true density (about 5.2 g/cm3). When the operation potential range is extended, the improvement in its cycle stability has attracted more attention. The extension of its operation potential can be realized by partial replacement of Co by Ni and Mn or by surface modification. However, Ni and Mn replacing partial Co results in decreased true density; for example, the true density of LiNi0.5Mn0.3Co0.2O2 is about 4.6 g/cm3. In this case, the increase in its practical energy density is impossible. As a result, the surface modification technology becomes very important to extend its operation potential range. In this article, an Al2O3-coated LiCoO2 cathode was synthesized. X-ray diffraction test did not show any impurity. Scanning electron spectroscopy measurements showed that the basic microstructure of pristine LiCoO2 grain is sustained after coating Al2O3. The surface characteristic of pure and Al2O3-coated LiCoO2 was also analyzed using an X-ray photoelectron spectroscopy (XPS) technique. Unusual XPS peaks of O 1s, Al 2p, and Co 2p binding energy were found and may be caused by the possible H existence in crystal structure. The electrochemical behavior was systematically investigated, and the cathode was cycled at different charge cutoff voltages (4.30∼4.60 V). The charge-discharge and cyclic voltammetry measurements showed an obviously improved cyclic performance after coating Al2O3. The electrocatalytic activity is not clearly changed before and after coating Al2O3. From our systematical investigation, it could be concluded that the Al2O3-coated LiCoO2 cathode is suitable for practical application in the potential range of 3.70∼4.50 V vs. Li/Li+.
      PubDate: 2016-05-01
  • Acacia gum-assisted co-precipitating synthesis of LiNi 0.5 Co 0.2 Mn 0.3 O
           2 cathode material for lithium ion batteries
    • Abstract: Abstract LiNi0.5Co0.2Mn0.3O2 particles of uniform size were prepared through carbonate co-precipitation method with acacia gum. The precursor of carbonate mixture was calcined at 800 °C, and a well-crystallized Ni-rich layered oxide was got. The phase structure and morphology were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The micro-sized particles delivered high initial discharge capacity of 164.3 mA h g−1 at 0.5 C (1 C = 200 mA g−1) between 2.5 and 4.3 V with capacity retention of 87.5 % after 100 cycles. High reversible discharge capacities of 172.4 and 131.4 mA h g−1 were obtained at current density of 0.1 and 5 C, respectively. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were performed to further study the LiNi0.5Co0.2Mn0.3O2 particles. Anyway, the excellent electrochemical performances of LiNi0.5Co0.2Mn0.3O2 sample should be attributed to the use of acacia gum.
      PubDate: 2016-05-01
  • Synthesis of δ-MnO 2 film on FTO glass with high electrochemical
    • Abstract: Abstract δ-Manganese dioxide (MnO2) has been proved to own the excellent electrochemical performances for a long time. But few of studies report the electrochemical performances of δ-MnO2 film. Here, we synthesize δ-MnO2 film on fluorine-doped tin oxide (FTO) glass via a simple redox reaction at the room temperature. The X-ray diffraction (XRD) and Raman spectroscopy are used to confirm the physical structure, whilst cyclic voltammetry and galvanostatic charge-discharge measurements are performed to investigate the electrochemical performances. Encouragingly, δ-MnO2 film delivers a high specific capacitance (C s) of 350.5 F g−1 at 100 mV s−1 and 275.0 F g−1 at 5 A g−1. The capacitance retention of δ-MnO2 film can be up to 100 % after being charge/discharge at 2 A g−1 with 1000 cycles. This research might further indicate that δ-MnO2 film is a promising electrode material for supercapacitors.
      PubDate: 2016-05-01
  • Structural and electrical characterizations of 50:50 PVA:starch blend
           complexed with ammonium thiocyanate
    • Abstract: Abstract The present work deals with the preparation and characterization of polymer blend electrolyte films. Glutaraldehyde is used as a cross-linker to cross-link polymers polyvinyl alcohol (PVA) and starch for the proper film formation. Structural characterizations such as X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) have been performed. X-ray diffraction is done to investigate the amorphous nature of the sample. FTIR study confirms about the complexation of salt with the polymer and interaction of thiocyanate ion with the polymer matrix. Electrical characterizations were done using impedance spectroscopy. DC and AC ionic conductivity was obtained at varying salt concentration in the films which shows maximum ionic conductivity of the polymer electrolyte containing 30 wt% of salt content. The AC conductivity behaviour of the polymer electrolyte follows Jonscher’s power law. Dielectric parameters such as dielectric constant, dielectric loss and loss tangent have been determined. Relaxation time is obtained and decreases to lower value with the increase in the salt concentration in the polymer electrolyte.
      PubDate: 2016-05-01
  • Interaction of Li 1+x (Ni,Mn,Co)O 2 cathode materials with single and
           complex oxides at 900 °C
    • Abstract: Abstract In order to find efficient barrier materials and inert dopants for the high temperature processing of Li-ion battery cathode materials, a chemical stability of Li1+x (Ni,Mn)O2 at 900 °C in air in contact with Al2O3, Nb2O5, SnO2, TiO2, and CeO2 is studied. The interaction of Li1+x (Ni,Mn)O2 with Al2O3, Nb2O5, and SnO2 results in the formation of the corresponding complex oxides—LiAlO2, Li3NbO4, and Li2SnO3. A first stage of the chemical degradation of Li1+x (Ni,Mn)O2 is usually accompanied by the transformation of its hexagonal crystal structure into the cubic one. The reaction of Li1+x (Ni,Mn)O2 with titania is accompanied by the disappearance of TiO2 and the formation of the Li1+x (Ni,Mn)O2-based solid solution. XRD analysis confirmed the absence of chemical interaction of Li1+x (Ni,Mn)O2 with CeO2 while SEM data demonstrated the absence of eutectic melting at 900 °C. The similar absence of traces of the high temperature chemical interaction with Li1+x (Ni,Mn)O2 is found also for LiAlO2, Li3NbO4, and Li2SnO3. Galvanostatic and cyclic voltammetry studies of Li1+x (Ni,Mn,Co)O2–CeO2 composites demonstrated the increase in the initial discharge capacity of the composite cathodes compared to the native Li1+x (Ni,Mn,Co)O2.
      PubDate: 2016-05-01
  • Influence of heat treatment process in In 2 O 3 -MWCNTs as photoanode in
    • Abstract: Abstract Indium oxide-multi-walled carbon nanotubes (In2O3-MWCNTs) were prepared by sol-gel method for DSSCs. The synthesis of indium oxide (In2O3) was carried out by dissolving indium chloride (InCl3) in a solvent of 2-methoxyethanol. Different annealing temperatures of 400, 450, 500, 550, and 600 °C were proposed in this study. The changes in the structural properties were analyzed by means of X-ray diffraction (XRD) and atomic force microscopy (AFM) analysis. The XRD spectrum estimated the average crystallite sizes of 3 nm for each sample. AFM results indicated very rough surface area of the films where it increased linearly from 1.8 to 11 nm as the annealing temperature increases. The In2O3-MWCNTs-based DSSC exhibited good photovoltaic performance with power conversion efficiency (η), photocurrent density (J sc ), open circuit voltage (V oc ), and fill factor (FF) of 1.13 %, 5.5 mA/cm2, 0.53 V, and 0.42, respectively. Even though the film annealed at 450 °C exhibited low τ eff, it achieved the greatest D eff of 29.67 cm2 s−1 which provides an efficient pathway for the photogenerated electrons with minimum electron recombination loss that increased the J sc and V oc in the DSSC. The obtained structural and electron transport analysis was proposed as a suitable benchmark for In2O3-MWCNTs-based dye-sensitized solar cell (DSSCs) application. Hence, this study suggests that the optimum temperature for In2O3-MWCNTs is at annealing temperature of 450 °C prepared via sol-gel method.
      PubDate: 2016-05-01
  • Electrochemical recycling of cell phone Li-ion batteries: application as
           corrosion protector of AISI 430 stainless steel in artificial seawater
    • Abstract: Abstract This article aims to present a new alternative to waste management of spent Li-ion batteries from cell phones. In this sense, the proposed is recycling the cobalt from Li-ion cathode by electrodeposition and apply it as corrosion protector of AISI 430 stainless steel. Thus, two greatest environmental problems can be solved, producing a low-cost and high-corrosion-resistant stainless steel. The cobalt electrodeposition bath came from acid dissolution of spent Li-ion cathode with chemical formula LiCoO2. The charge efficiency for cobalt electrodeposition in −1.0 V and pH = 3 reaches 95 %. A protective layer of Co3O4 was successfully obtained by treatment of AISI 430 stainless steel with cobalt electrodeposited at 800 °C for 200 h in air atmosphere. The corrosion current of AISI 430 stainless steel in artificial seawater was reduced from 30 to 0.76 μA cm−2. The treatment proposed produces a AISI 430 stainless steel with double of corrosion resistance and half of cost if compared with AISI 304 stainless steel.
      PubDate: 2016-05-01
  • A novel synthesis of size-controllable mesoporous NiMoO 4 nanospheres for
           supercapacitor applications
    • Abstract: Abstract A novel hydrothermal emulsion method is proposed to synthesize mesoporous NiMoO4 nanosphere electrode material. The size of sphere-shaped NiMoO4 nanostructure is controlled by the mass ratio of water and oil phases. Nickel acetate tetrahydrate and ammonium heptamolybdate were used as nickel and molybdate precursors, respectively. The resultant mesoporous NiMoO4 nanospheres were characterized by X-ray diffraction, N2 adsorption and desorption, scanning electron microscopy, and transmission electron microscopy. The electrochemical performances were evaluated by cyclic voltammetry (CV), cyclic chronopotentiometry (CP), and electrochemical impedance spectroscopy (EIS) in 6 M KOH solution. The typical mesoporous NiMoO4 nanospheres exhibit the large specific surface area of 113 m2 g−1 and high specific capacitance of 1443 F g−1 at 1 A g−1, an outstanding cyclic stability with a capacitance retention of 90 % after 3000 cycles of charge-discharge at a current density of 10 A g−1, and a low resistance.
      PubDate: 2016-05-01
  • Influence of supporting electrolytes on the structure of electrodeposited
           SnO 2 thin films for energy storage applications
    • Abstract: Abstract Different SnO2 nanostructures (SnO2Ns) were directly electrodeposited on the surface of anodized copper (Cu) substrates via the potentiostatic electrodeposition method with addition of supporting electrolytes. The effects of the supporting electrolytes and the electrodeposition parameters on the evolution of nanostructures and on the electrochemical properties of the SnO2Ns were systematically investigated using field emission scanning electron microscope (FESEM) and electrochemical methods including cyclic voltammetry (CV) and chronoamperometry (CA). The results confirmed that SnO2Ns exhibit alloying/de-alloying reactions with Li+ ions versus Ag/AgCl in aqueous electrolyte solution (LiOH·H2O and Li2CO3). The super capacitor performance of the SnO2Ns was investigated in 0.5-M Na2SO4 aqueous solution, and the highest specific capacitance of 110 Fg−1 at a scan rate of 5 mV s−1 was obtained for SnO2 microspheres made up of nanocubes. Our study shows that supporting electrolytes and electrodeposition parameters play the significant role in the growth of SnO2Ns and its electrochemical properties.
      PubDate: 2016-04-29
  • Facile synthesis of hierarchical porous Ni-rich LiNi 0.6 Co 0.2 Mn 0.2 O 2
           cathode material with superior high-rate capability
    • Abstract: Abstract A hierarchical porous nickel-rich LiNi0.6Co0.2Mn0.2O2 cathode is successfully prepared for the first time using a facile ammonia-induced method, wherein ammonia molecules play a key role in fabricating the complex architecture, and neither templates nor precipitants are employed. Hierarchical flower-like precursor with ultra-thin nanosheets is formed during the ammonia-induced reaction, and then, the porous product is obtained during the sintering process. The X-ray diffraction pattern demonstrates that the sample has a well-defined α-NaFeO2 structure with very low-cation disorder. The peculiar hierarchical porous morphology and ideal structure endow this material-enhanced electrochemical performance. It delivers discharge capacities of 173, 138, 111, 97, and 82 mAh g−1 at 0.1 C, 1 C, 5 C, 10 C, and 20 C, respectively, and maintains 91 % of its initial discharge capacity after 100 cycles at 1 C. The results reveal that this method is facile and feasible to synthesize high-rate Nickel-rich material.
      PubDate: 2016-04-28
  • An investigation on the unsatisfactory rate capability of spherical LiNi
           1/3 Co 1/3 Mn 1/3 O 2 particles prepared by using Na 2 CO 3 as a
    • Abstract: Abstract Spherical LiNi1/3Co1/3Mn1/3O2 particles were successfully synthesized using Na2CO3 as a precipitant. Electrochemical measurements indicate that the as-synthesized spherical particles deliver a high reversible capacity of above 180 mAh g−1 at 0.1 C in the voltage range of 2.8–4.4 V and display an excellent cyclic performance at 0.5 C. However, unsatisfactory rate capability was detected for the as-prepared spherical particles. The reason for the unsatisfactory rate capability was investigated through a comparison of the properties of the as-synthesized spherical particles versus the ball-milled samples via a combination of specific surface areas test, electronic conductivity measurement, and electrochemical impedance spectroscopy. The results show that both the rate capabilities of cathode materials and the electronic conductivities of the mixtures of active material, conductive additive, and binder are highly improved when the secondary spherical particles were broken, indicating that the poor electronic conductivity of electrode caused by the large secondary spherical particles with a great amount of nano-pores is a significant factor for the unsatisfactory rate capability.
      PubDate: 2016-04-27
  • Semiconducting SnO 2 -TiO 2 (S-T) composites for detection of SO 2 gas
    • Abstract: Abstract SnO2-TiO2 (S-T) composites with different molar ratios were prepared by mechanical mixing followed by sintering at 700 °C for 4 h in air. The structural and microstructural properties of the composites were investigated using powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). S-T composites were investigated by introducing SO2 to test their chemical stability using PXRD and SEM coupled with energy dispersive X-ray (EDX) analysis. The sensing performance was measured at different temperatures using various SO2 concentrations (10–100 ppm). A composite comprising 25 mol% of SnO2 and 75 mol% TiO2 (S25-T75) exhibited the highest sensitivity comparing to other S-T composites studied under the presently investigated conditions. t 90 (90 % of response time) was found to be ∼5 min for thick pellet (~2 mm in thickness). SO2 sensing mechanism has been explained through the band structure model.
      PubDate: 2016-04-26
  • Hydrothermal impregnation synthesis of cobalt pentlandite as anode
           material of H 2 S SOFC
    • Abstract: Abstract In the present work, cobalt pentlandite (Co9S8) is studied as a solid oxide fuel cells (SOFC) anode material which is stable in H2S-containing fuels and is promising in coal-based SOFCs. Co9S8 is synthesized via a simple hydrothermal method. Uniform and fine Co9S8 particles are deposited on to the YSZ skeleton directly by using hydrothermal impregnation method and adhered to the skeleton closely after heat treating in N2. The symmetrical cells are measured in the presence of 50 ppm H2S–H2 to determine the electrochemical performance at intermediate temperatures. The polarization resistance is only 0.3385 Ω cm2 at 650 °C. It is concluded that Co9S8 exhibits a combination of good electronic conductivity and catalytic activity and has the potential to be used as a sulfur-tolerant anode material of SOFCs.
      PubDate: 2016-04-05
  • A heatproof separator for lithium-ion battery based on nylon66 nanofibers
    • Abstract: Abstract The safety of lithium-ion battery is closely related to the anti-shrink and heatproof stability of the separator. In this paper, electrospun nylon66 (PA66) nanofiber-based membrane is used as lithium-ion battery separator, showing good thermodynamics properties via thermogravimetric analysis (TG), thermal shrinkage experiment, and tension test. Furthermore, electrospun nylon66 separator based battery exhibits better safety than the battery applying Celgard commerce separator under the condition of high temperature and severe vibration. Meanwhile, the electrochemical properties of both batteries are nearly identical. These facts prove that the electrospun nylon66 separator is an ideal separator candidate for power lithium-ion battery of electric vehicles. In addition, the nylon66 separator annealed in the air has higher tensile strength and better property of elongation than the unannealed one.
      PubDate: 2016-04-02
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