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Full-Text Articles in Engineering

Me-Em Enewsbrief, September 2015, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University Sep 2015

Me-Em Enewsbrief, September 2015, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

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Synthesis, Structure And Electrochemical Performance Of Na2Mnsio4/C Cathode Material For Na-Ion Batteries, Shou-Ding Li, Jiang-Huai Guo, Yong Xie, Jin-Xiao Mi, Yong Yang Aug 2015

Synthesis, Structure And Electrochemical Performance Of Na2Mnsio4/C Cathode Material For Na-Ion Batteries, Shou-Ding Li, Jiang-Huai Guo, Yong Xie, Jin-Xiao Mi, Yong Yang

Journal of Electrochemistry

As a promising cathode material for sodium ion batteries, pure phase Na2MnSiO4/C nanocomposite was successfully synthesized by a sol-gel method with a citric acid as a complex agent. The as prepared material was characterized by XRD, FTIR, SEM and TEM techniques. XRD and Rietveld refinement results indicated that the sample was indexed as monoclinic structure with space group of Pn. It was observed by SEM and TEM that the obtained product consisted of micro-scaled secondary particles, which were composed of NaMnSiO4 nanocrystallites and amorphous carbon network. More importantly, the uniform carbon network in the …

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Preparation And Characterization Of Carbon Supported Pd-Sb Composite Nanocatalysts For Formic Acid Electrooxidation, Long-Long Wang, Xiao-Lu Cao, Ya-Jun Wang, Jin-Hao Ping, Qiao-Xia Li Aug 2015

Preparation And Characterization Of Carbon Supported Pd-Sb Composite Nanocatalysts For Formic Acid Electrooxidation, Long-Long Wang, Xiao-Lu Cao, Ya-Jun Wang, Jin-Hao Ping, Qiao-Xia Li

Journal of Electrochemistry

Palladium is considered as an efficient anode catalyst with high catalytic activity for electrooxidation of formic acid. To further improve the catalytic activity and stability, alloying or surface modification with Sb is an effective way. In this work, the well dispersed carbon supported Pd-Sb composite nanocatalysts (Pd-Sb/C) were synthesized by traditional impregnation reduction method with trisodium citrate as the complexing agent, sodium borohydride as the reducing agent. The morphologies of Pd-Sb/C and the effects of molar ratio of Pd to Sb on the electrocatalytic properties of Pd-Sb/C for HCOOH electrooxidation were studied. The XRD and XPS analyses on the as-prepared …

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Effect Of Adsorption Potential On Co Oxidation At Au@Pt Nanoparticles Electrodes, A Surface Enhanced Raman Spectroscopic Study, Pu Zhang, Yi Wei, Yong-Li Zheng, Yan-Xia Chen, Zhong-Qun Tian Aug 2015

Effect Of Adsorption Potential On Co Oxidation At Au@Pt Nanoparticles Electrodes, A Surface Enhanced Raman Spectroscopic Study, Pu Zhang, Yi Wei, Yong-Li Zheng, Yan-Xia Chen, Zhong-Qun Tian

Journal of Electrochemistry

The adsorption/oxidation of CO on the 55 nm [email protected] nm Pt nanoparticles electrode in both potentiodynamic and potentiostatic modes were investigated by surface enhanced Raman spectroscopy in a thin layer electrochemical flow cell under controlled mass transport, with the aim of clarifying the origin CO oxidation at lower electrode potentials (in current pre-wave region of corresponding cyclic voltammograms). Our results demonstrated that the CO oxidation kinetics differed significantly from the three kinds of different CO adsorption history, with almost no CO oxidation current in the pre-peak potential region after 0.35 VRHE CO adsorption with or without subsequent holding the …

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Broadband Sum-Frequency Generation Spectroscopic Invstigations Of Thiocyanate On Polycrystalline Au Electrode In Alkaline Solutions, Mei Xu, Jing-Jing Wang, Zhi-Chao Huangfu, Ng Ying Wa, Yu-Han He, Zhao-Hui Wang Aug 2015

Broadband Sum-Frequency Generation Spectroscopic Invstigations Of Thiocyanate On Polycrystalline Au Electrode In Alkaline Solutions, Mei Xu, Jing-Jing Wang, Zhi-Chao Huangfu, Ng Ying Wa, Yu-Han He, Zhao-Hui Wang

Journal of Electrochemistry

Broadband sum frequency generation (BB-SFG) spectroscopy has been used to investigating the potential-dependent adsorption behaviors of thiocyanate ions on polycrystalline Au electrode in alkaline solutions. During the positive scan, a change in the Stark slope (dωC-N/dE) for C—N stretching mode can be observed in the range of -1.1 V ~ 0.2 V (vs. SCE), which implies that the orientation of adsorbed thiocyanate ions at Au electrode surface changes from N-bound (dωC-N/dE=45 cm-1·V-1) form to S-bound (dωC-N/dE = 16.2 cm-1·V-1 …

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Synthesis And Electrochemical Performance Of Mn3O4/Graphene Composites, Shan-Shan Yang, Qian Zhang, Xiong-Gui Lin, Ming-Sen Zheng, Quan-Feng Dong Aug 2015

Synthesis And Electrochemical Performance Of Mn3O4/Graphene Composites, Shan-Shan Yang, Qian Zhang, Xiong-Gui Lin, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The Mn3O4/Graphene composites were synthesized by hydrothermal method with the in-situ redox reaction of graphene oxide (GO) and manganese acetate (Mn(Ac)2). The phase structures and morphologies of the materials were characterized by XRD, SEM and TEM. The XPS and IR techniques were used for studying the residual function groups of reduced graphene oxide (RGO). The electrochemical performances of the hybrids were tested in a coin cell. Results showed that the composites prepared with the addition of ammonia water (RM-A) have better performance. The graphenes in RM-A were better-reduced and the Mn3O4 …

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Tungsten Carbide/Carbon Electrode Material Synthesized By Block Copolymer Template Method, Xiao-Ling Lang, Ye-Kun Jiang, Mei-Qin Shi, Ling-Zhi Kang, Chun-An Ma Aug 2015

Tungsten Carbide/Carbon Electrode Material Synthesized By Block Copolymer Template Method, Xiao-Ling Lang, Ye-Kun Jiang, Mei-Qin Shi, Ling-Zhi Kang, Chun-An Ma

Journal of Electrochemistry

At present, one of the major hurdles for commercialization of system with direct methanol fuel cell (DMFC) is still the requirement of a significant amount of platinum (Pt) catalyst to achieve an acceptable power density. Pt and Pt-based metals are expensive due to limited supplies. In order to find the catalyst alternative to the Pt metal, we selected tungsten carbide (WC) and its composites as the study object. We synthesized WC with carbon materials as the suitable support to modify the electronic structure and to increase the specific surface area of WC. In this study, tungsten carbide/carbon (WC/C) was prepared …

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Electrochemical Removal Of Low Concentration Pb(Ii) From Aqueous Solution Based On Ppy/α-Zrp/Ptcf Electrode, Ru-Yi Chen, Peng-Le Zhang, Sen-Liang Liao, Zhong-De Wang, Xiao-Gang Hao Aug 2015

Electrochemical Removal Of Low Concentration Pb(Ii) From Aqueous Solution Based On Ppy/α-Zrp/Ptcf Electrode, Ru-Yi Chen, Peng-Le Zhang, Sen-Liang Liao, Zhong-De Wang, Xiao-Gang Hao

Journal of Electrochemistry

A novel organic-inorganic hybrid film consisting of polypyrrole/α-zirconium phosphate (PPy/α-ZrP) was prepared in an aqueous phase by cyclic voltammetry method. It was proved by FT-IR, XRD and XPS characterizations that the electroactive PPy/α-ZrP hybrid film was synthesized successfully. The PPy/α-ZrP film electrode prepared on a porous three-dimensional carbon felt (PTCF) was used for removal of a low concentration of Pb(II) ions from an aqueous solution by electrochemically switched ion exchange (ESIX). A quick uptake and release rate of Pb(II) onto the film electrode was obtained by adjusting redox state of the hybrid film. The removal efficiency and adsorption capacity of …

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Mechanism Study On The Electrocatalytic Oxidation Of Acetylene To Oxalic Acid, Xiu-Li Song, Rui-Long Jia, Wen-Yan Dong, Zhen-Hai Liang Aug 2015

Mechanism Study On The Electrocatalytic Oxidation Of Acetylene To Oxalic Acid, Xiu-Li Song, Rui-Long Jia, Wen-Yan Dong, Zhen-Hai Liang

Journal of Electrochemistry

A new method of electrocatalytic synthesis oxalic acid from acetylene was explored and the synthesized oxalic acid was characterized by Ultraviolet-visible spectrophotometry (Uv-vis) and Infrared spectroscopy (IR). First-principles calculations were carried out to examine the adsorption of acetylene over the Pt(111) surface. The electrocatalytic oxidation behavior of acetylene has been investigated on a Pt electrode by cyclic voltammetry (CV) and steady-state polarization in Na2SO4 solution. The formation mechanism of oxalic acid in the Na2SO4 solution was proposed and the transfer coefficients of the reaction were calculated. The results show that acetylene molecule tends to …

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Effect Of Carbon Nanotubes On Anodic Properties Of Ti/Ru-Ir-Sn Oxides, Feng Lian, Yong-Lei Xin, Bo-Jiang Ma, Li-Kun Xu Aug 2015

Effect Of Carbon Nanotubes On Anodic Properties Of Ti/Ru-Ir-Sn Oxides, Feng Lian, Yong-Lei Xin, Bo-Jiang Ma, Li-Kun Xu

Journal of Electrochemistry

The Ru-Ir-Sn metal oxide anodes coated on titanium (Ti/Ru-Ir-Sn) were prepared by thermal decomposition. The effects of amounts of carbon naotubes (CNTs) on anodic properties were studied by TGA, SEM, EDS, cyclic voltammetry, EIS, polarization measurements and accelerated life test. The thermogravimetric analysis and EDS spectrum data showed that the high temperature oxidation decomposition of CNTs did not take place under the condition of the sintering temperature of 470 ℃, and the CNTS still existed in the anode coating in an element form. Compared with the contrast samples, the surface crack of the coating increased, but remained typical morphology. Adding …

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Preparation And Enhanced Rate Capability Of Spinel Limn1.9Al0.1O3.95F0.05, Jun-Yan Hu, Meng-Meng Wang, Hong-Tao Liu Aug 2015

Preparation And Enhanced Rate Capability Of Spinel Limn1.9Al0.1O3.95F0.05, Jun-Yan Hu, Meng-Meng Wang, Hong-Tao Liu

Journal of Electrochemistry

Spinel LiMn1.9Al0.1O3.95F0.05 cathode materials with good crystallinity were synthesized by a sol-gel process followed with a high-temperature solid reaction. The effects of partial substitution of Al for Mn, and F for O on the structure and the electrochemical performance were investigated. The results showed that LiMn1.9Al0.1O3.95F0.05 exhibited the same crystalline state as LiMn2O4, but much better electrochemical stability at higher rate cycling. As a result, LiMn1.9Al0.1O3.95F0.05 could maintain stable electrochemical lithium storage even suffering from …

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An Investigation On Electrochemical Performance Of Supercapacitor Electrode Materials Prepared By Mno2 With Four Different Crystal Forms, Zhen-Kun Wei, Xiao-Zhen Hua, Ke Xiao, Xian-Liang Zhou, Zhi-Guo Ye Aug 2015

An Investigation On Electrochemical Performance Of Supercapacitor Electrode Materials Prepared By Mno2 With Four Different Crystal Forms, Zhen-Kun Wei, Xiao-Zhen Hua, Ke Xiao, Xian-Liang Zhou, Zhi-Guo Ye

Journal of Electrochemistry

Four types of α-MnO2, β-MnO2, γ-MnO2 and δ-MnO2 powders were synthesized by relatively simple methods. The differences in crystal structures and surface morphologies for these forms of MnO2 were investigated by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA) and specific surface area analysis (BET). The electrochemical performances were characterized by cyclic voltammetry (CV) and stability analysis. Based on the experimental results, four kinds of MnO2 electrodes showed good capacity properties, and the α-MnO2 electrode had the largest specific capacity due to the highest specific surface …

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Reaction Mechanisms Study Of Pb Electrodes In Sulfuric Acid And Sodium Sulfate Solutions By Eqcm, Xian-Ping Zou, Zong-Xuan Kang, Yu-Lan Huang, Dong Shu, Ya-Yun Zhong, Jun-Nan Hao, Yu-Qing Liao Aug 2015

Reaction Mechanisms Study Of Pb Electrodes In Sulfuric Acid And Sodium Sulfate Solutions By Eqcm, Xian-Ping Zou, Zong-Xuan Kang, Yu-Lan Huang, Dong Shu, Ya-Yun Zhong, Jun-Nan Hao, Yu-Qing Liao

Journal of Electrochemistry

Surface reaction processes of Pb electrodes were investigated in H2SO4 and Na2SO4 solutions by LSV, CV and EQCM. The results in the voltammogram and the mass change curve of the Pb electrode indicated that the oxide products of lead included PbSO4 and PbO·PbSO4 in sulfuric acid solution with a positive-going potential scan from -1.0 V to -0.4 V and then PbO·PbSO4 transformed into PbSO4. However, the oxide product of lead was only PbSO4 in sodium sulfate solution. The experimental results revealed that the acid solution is necessary for the …

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System And Method For Estimating States Of Spacecraft In Planet-Moon Environment, Piyush Grover Aug 2015

System And Method For Estimating States Of Spacecraft In Planet-Moon Environment, Piyush Grover

Department of Mechanical and Materials Engineering: Faculty Publications

A method estimates a state of a spacecraft in a planet-moon environment by executing iteratively a particle filter. The particle filter comprising integrates individually states of each particle of the particle filter according to a probability-evolution equation using a model of the state of the spacecraft represented as a planar circular restricted three-body problem and determines a prior probability of each particle as a previous posterior probability of a corresponding particle during a previous iteration. A joint probability distribution of the state of the spacecraft is determines using the states of each particle and the prior probabilities of each particle …

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Dynamic Characteristics Of Biologically Inspired Hair Receptors For Unmanned Aerial Vehicles, Manohar Chidurala Aug 2015

Dynamic Characteristics Of Biologically Inspired Hair Receptors For Unmanned Aerial Vehicles, Manohar Chidurala

LSU New Orleans Theses and Dissertations

The highly optimized performance of nature’s creations and biological assemblies has inspired the development of their engineered counter parts that can potentially outperform conventional systems. In particular, bat wings are populated with air flow hair receptors which feedback the information about airflow over their surfaces for enhanced stability and maneuverability during their flight. The hairs in the bat wing membrane play a role in the maneuverability tasks, especially during low-speed flight. The developments of artificial hair sensors (AHS) are inspired by biological hair cells in aerodynamic feedback control designs. Current mathematical models for hair receptors are limited by strict simplifying …

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Effect Of Surface Omniphobicity On Drying By Forced Convection, Madani A. Khan, Jeffrey Alston, Andrew Guenthner Aug 2015

Effect Of Surface Omniphobicity On Drying By Forced Convection, Madani A. Khan, Jeffrey Alston, Andrew Guenthner

STAR Program Research Presentations

Low energy surfaces can strongly repel both oil and water. Recently these surfaces have been fabricated on various substrates including fabric, aluminum, stainless steel and many other materials. In this experiment we explore the use of low energy surface deposition on aluminum alloy, stainless steel and silicon substrates, to enhance the drying rate of liquids removed from the surface by forced convection. We control surface roughness by substrate abrasion and by the growth of Al2O3 nanograss to enhance liquid repellence by use of a hierarchical texture. Liquid repellence of the substrates is measured by contact angles of …

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An Estimate Of The Second-Order In-Plane Acceleration Sensitivity Of A Y-Cut Quartz Thickness-Shear Resonator, Huijing He, Jiashi Yang, John A. Kosinski Aug 2015

An Estimate Of The Second-Order In-Plane Acceleration Sensitivity Of A Y-Cut Quartz Thickness-Shear Resonator, Huijing He, Jiashi Yang, John A. Kosinski

Department of Mechanical and Materials Engineering: Faculty Publications

We perform a theoretical analysis of the second-order in-plane acceleration sensitivity of a Y-cut quartz thick-ness-shear mode resonator. The second-order nonlinear theory of elasticity for anisotropic crystals is used to determine the biasing fields in the resonator under in-plane acceleration. The acceleration-induced frequency shift is determined from a per-turbation analysis based on the plate equations for small-amplitude vibrations superposed on a finite bias. We show that, whereas the first-order acceleration-induced frequency shift is zero for a structurally symmetric resonator under in-plane ac-celeration, the second-order frequency shift is nonzero and is quadratic in the acceleration. As the fourth-order nonlinear elastic constants …

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Structure And Optical Properties Of Transition Metal Dichalcogenides (Tmds) – Mx2 (M = Mo, W & X = S, Se) Under High Pressure And High Temperature Conditions, Nirup Reddy Bandaru Aug 2015

Structure And Optical Properties Of Transition Metal Dichalcogenides (Tmds) – Mx2 (M = Mo, W & X = S, Se) Under High Pressure And High Temperature Conditions, Nirup Reddy Bandaru

UNLV Theses, Dissertations, Professional Papers, and Capstones

Layered structured materials such as transition metal dichalcogenides (TMDs) have gained immense interest in recent times due to their exceptional structural, electrical and optical properties. Recent studies show semiconducting TMDs such as MX2 (M= Mo, W & X = S, Se) could be used as potential shock absorbing material, which has resulted in extensive studies on structural stability of these materials under the influence of high pressure. Understanding the structural stability of transition metal dichalcogenides (TMDs) such as MoS2, MoSe2, WS2, and WSe2 under high pressure has been very challenging due to contradicting observations and interpretations reported in the …

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Feasibility Study Of Custom Manufacturing Of Ionic Polymer-Metal Composite Sensors, Shelby E. Nelson Aug 2015

Feasibility Study Of Custom Manufacturing Of Ionic Polymer-Metal Composite Sensors, Shelby E. Nelson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ability to create an ion exchange membrane with any shape or thickness through custom manufacturing techniques is highly desirable in ionic polymer-metal composite (IPMC) research. This is caused by the poor selection and limited availability of certain thicknesses of commercial ion exchange membranes. The objective of this study is to determine the feasibility of manufacturing custom ion exchange membranes for IPMC sensors. The manufacturing methods used in this study are extrusion, injection molding, and hot pressing. A commercial membrane from Golden Energy Fuel Cells (GEFC) is used as a comparison. After the membranes are fabricated, certain properties of the …

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Biodegradable Medical Device Having An Adjustable Degradation Rate And Methods Of Making The Same, Yuebin Guo, Michael Sealy, Meisam Salahshoor Pirsoltan Jul 2015

Biodegradable Medical Device Having An Adjustable Degradation Rate And Methods Of Making The Same, Yuebin Guo, Michael Sealy, Meisam Salahshoor Pirsoltan

Department of Mechanical and Materials Engineering: Faculty Publications

Disclosed herein are biodegradable medical devices comprising biodegradable material (e.g., magnesium-calcium alloys) having an adjustable rate of degradation that can be used in various applications, including, but not limited to, drug delivery applications, cardiovascular applications, and orthopedic applications to make biodegradable and biocompatible devices. Also disclosed herein are methods of making biodegradable medical devices comprising biodegradable materials by using, for instance, hybrid dry cutting/hydrostatic burnishing.

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Traction-Separation Relationships For Hydrogen-Induced Grain Boundary Embrittlement In Nickel Via Molecular Dynamics Simulations, Wesley Allen Barrows Jul 2015

Traction-Separation Relationships For Hydrogen-Induced Grain Boundary Embrittlement In Nickel Via Molecular Dynamics Simulations, Wesley Allen Barrows

Graduate Theses and Dissertations

The deleterious effects of atomic and molecular hydrogen on the mechanical properties of metals have long been observed. Although several theories exist describing the mechanisms by which hydrogen negatively influences the failure of materials, a consensus has yet to be reached regarding the exact mechanism or combination of mechanisms. Two mechanisms have gained support in explaining hydrogen’s degradative role in non-hydride forming metals: hydrogen-enhanced localized plasticity and hydrogen-enhanced decohesion. Yet, the interplay between these mechanisms and microstructure in metallic materials has not been explained. Accordingly, for this thesis, the three main objectives are: (i) to develop a numerical methodology to …

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Current Status And Prospect Of Cathode Materials For Lithium Sulfur Batteries, Lan Zhou, Ai-Shui Yu Jun 2015

Current Status And Prospect Of Cathode Materials For Lithium Sulfur Batteries, Lan Zhou, Ai-Shui Yu

Journal of Electrochemistry

Elemental sulfur has been extensively investigated as a promising candidate of cathode material for next generation lithium secondary batteries. However, some troublesome issues, such as the low electric conductivity of sulfur (5×10-30 S·cm-1) and the high solubility of lithium polysulfide intermediates in organic electrolytes, resulting in a low utilization of active material and a redox shuttling of dissolved polysulfide ions between the sulfur cathode and the lithium anode, which eventually leads to a deposition of insoluble and insulating Li2S2/Li2S on the electrode surface and a fast reduction in the specific capacity. …

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Research Status And Application Prospects Of Limnpo4 As A New Generation Cathode Material For Lithium-Ion Batteries, Lai-Fen Qin, Yong-Gao Xia, Li-Peng Chen, Hua-Sheng Hu, Feng Xiao, Zhao-Ping Liu Jun 2015

Research Status And Application Prospects Of Limnpo4 As A New Generation Cathode Material For Lithium-Ion Batteries, Lai-Fen Qin, Yong-Gao Xia, Li-Peng Chen, Hua-Sheng Hu, Feng Xiao, Zhao-Ping Liu

Journal of Electrochemistry

Olivine-structured lithium manganese phosphate (LiMnPO4) has the following advantages: excellent thermal stability, low cost, high safety and environmental benignity. Importantly, the theoretical energy density of LiMnPO4 is about 20% higher than that of commercialized LiFePO4 due to its higher Li+ intercalation potential of 4.1 V (vs. Li+/Li). Moreover, the high operating voltage of LiMnPO4 is compatible with present non-aqueous organic electrolytes of lithium-ion batteries. Therefore, LiMnPO4 is considered as a next generation cathode material for lithium-ion batteries. However, LiMnPO4 suffers from poor electronic conductivity and low lithium diffusivity, resulting in …

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Preparations And Applications Of Layered Carbon And Layered Carbon-Pbso4 Composite, Shu-Kai Zhang, Hao Zhang, Wei-Hua Xue, Jie Cheng, Wen-Feng Zhang, Gao-Ping Cao, Hai-Lei Zhao, Yu-Sheng Yang Jun 2015

Preparations And Applications Of Layered Carbon And Layered Carbon-Pbso4 Composite, Shu-Kai Zhang, Hao Zhang, Wei-Hua Xue, Jie Cheng, Wen-Feng Zhang, Gao-Ping Cao, Hai-Lei Zhao, Yu-Sheng Yang

Journal of Electrochemistry

The layered carbon materials (similar to graphene) have been synthesized by chemical vapor deposition (CVD) on the cheap catalyst (potassium or sodium carbonate substrate). The layered-carbon- lead sulfate (PbSO4) composite could be prepared by in situ chemical deposition based on the layered carbon. The XRD, SEM and TEM results showed that the layered carbon materials was amorphous carbon layer, and the composite was a compound made of fine lead sulfate grains and layered carbon. Thermogravimetric analysis determined the carbon content in the composite. Adding a certain amount of layered carbon or layered-carbon-PbSO4 composite into negative active materials …

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Preparation Of Zro2-Doped Nb/Pbo2 Electrode And Electrocatalytic Performance Of Methyl Orange Degradation, Li Zhang, Wen-Yan Dong, Tai-Lai Yang, Zhen-Hai Liang Jun 2015

Preparation Of Zro2-Doped Nb/Pbo2 Electrode And Electrocatalytic Performance Of Methyl Orange Degradation, Li Zhang, Wen-Yan Dong, Tai-Lai Yang, Zhen-Hai Liang

Journal of Electrochemistry

The zirconium oxide (ZrO2)-doped niobium based lead oxide (Nb/PbO2) electrode was prepared by electrodeposition. The microstructures and electrochemical properties of Nb/ZrO2+PbO2 electrode were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), linear sweep voltammetry, electrochemical impedance spectroscopy and cyclic voltammotry. In addition, the Nb/PbO2 electrode was used as an anode for the electrochemical degradation of methyl orange (MO). Results revealed that the ZrO2 doping made the Nb/PbO2 electrode surface denser and rougher with smaller sized crystal particles, which increased the specific surface area and enhanced the electrocatalytic activity of the …

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Electrochemical Mass Spectrometric Study Of Lithium-Oxygen Batteries, Xin-Xiu Yan, Li-Po Ma, Zhang-Quan Peng Jun 2015

Electrochemical Mass Spectrometric Study Of Lithium-Oxygen Batteries, Xin-Xiu Yan, Li-Po Ma, Zhang-Quan Peng

Journal of Electrochemistry

Mass Spectrometry, coupled with electrochemistry, is a powerful research tool to study mechanisms for a broad range of electrode reactions by identifying and quantifying reaction products and intermediates. In this review, we summarize the recent advances in the Li-O2 battery researches offered by electrochemical mass spectrometry based on our group investigations. These include the research progresses in electrolytes, cathode materials (electrocatalysts), and parasitic reactions, i.e., the key issues associated with Li-O2 research. In addition, we also discuss the effects of irreversible side reactions involved in battery systems on charge and discharge processes.

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Synthesis Of Graphene Wrapped Li-Rich Layered Metal Oxide And Its Electrochemical Performance, Meng-Yan Hou, Ke Wang, Xiao-Li Dong, Yong-Yao Xia Jun 2015

Synthesis Of Graphene Wrapped Li-Rich Layered Metal Oxide And Its Electrochemical Performance, Meng-Yan Hou, Ke Wang, Xiao-Li Dong, Yong-Yao Xia

Journal of Electrochemistry

In present work, lithium-rich layered transition metal oxide (LLO) was synthesized by a co-precipitation method in combination with a solid-state reaction. The graphene wrapped Li-rich layered oxide composite (LLO/Gra) was obtained by sintering the LLO/GO composite at 300 oC for 30 min in an air. The morphologies and the electrochemical performances were characterized by means of SEM, TEM, XRD, XPS, EIS and charge/discharge tests. The results indicated that the LLOe particles were uniformly wrapped with graphene. The resulting material exhibited better rate capability than that of pristine LLO since the wrapped graphene demonstrated the enhanced electronic conductivity. Accordingly, the …

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Research Progress In Carbon Coating On Lifepo4 Cathode Materials For Lithium Ion Batteries, Ning Zhang, Yong-Chang Liu, Cheng-Cheng Chen, Zhi-Qiang Zhu, Zhan-Liang Tao, Jun Chen Jun 2015

Research Progress In Carbon Coating On Lifepo4 Cathode Materials For Lithium Ion Batteries, Ning Zhang, Yong-Chang Liu, Cheng-Cheng Chen, Zhi-Qiang Zhu, Zhan-Liang Tao, Jun Chen

Journal of Electrochemistry

Olivine-structured LiFePO4 has been received much attention because of its flat voltage profile, low cost, abundant material supply and better environmental compatibility. However, the poor electronic and ionic conductivities have limited its application in industry. One of the best methods to improve the electrochemical performance is carbon coating. In this review, we summarize the recent developments of LiFePO4/C cathode. Moreover, the different effects caused by coating methods and carbon sources, as well as the mechanism of carbon coating on the properties of LiFePO4/C are reviewed.

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Enhancing Stability Of Pem Fuel Cell Catalysts Via Support Changing, Xiao-Hong Xie, Zi-Dong Wei Jun 2015

Enhancing Stability Of Pem Fuel Cell Catalysts Via Support Changing, Xiao-Hong Xie, Zi-Dong Wei

Journal of Electrochemistry

The Pt/C catalyst with highly dispersed Pt nanoparticles supported on carbon has been widely used as the state-of the-art catalyst in proton exchange membrane fuel cells (PEMFCs), while the durability of Pt/C is one of the major barriers for large-scale applications of PEMFCs. Thus, enhancing the stability of Pt/C has been a hot issue in this field. In this review, we summarize the recent progress in enhancing the catalyst stability in the view of support material. The future prospects of the PEMFCs catalyst should focus on adopting more stable supports or strengthening the interactions between Pt and supports.

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Pt/C Modified Proton Exchange Membrane For Improved Fuel Cell Performance, Zhi Cui, Chao Wang, Shui-Yun Shen, Feng-Jing Jiang, Jun-Liang Zhang Jun 2015

Pt/C Modified Proton Exchange Membrane For Improved Fuel Cell Performance, Zhi Cui, Chao Wang, Shui-Yun Shen, Feng-Jing Jiang, Jun-Liang Zhang

Journal of Electrochemistry

The property of proton exchange membrane greatly affects the performance of proton exchange membrane fuel cells (PEMFC). During the operation of a PEMFC, the water produced at the cathode, the water vapor from the humidified feed gas and the water migrated by electro-dragging will reach a balance in the membrane and determine the resistance of PEMFC, and thus affect the performance of PEMFC. Normally, the PEMFC performance strongly depends on the relative humidity of the feed gas, and the performance decreases at lower humidity as a result of lower proton conductivity of the membrane. In this paper, we proposed to …

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