Open Access. Powered by Scholars. Published by Universities.®

Engineering Science and Materials Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 4591 - 4620 of 5723

Full-Text Articles in Engineering Science and Materials

Electrochemical Characterization Of Positive Electrode Material Lini1/3Co1/3Mn1/3O2 In Different Electrolytes, Jing-Jing Liu, Wei-Hua Qiu, Ling-Yan Yu, Hai-Lei Zhao, Tao Li Nov 2006

Electrochemical Characterization Of Positive Electrode Material Lini1/3Co1/3Mn1/3O2 In Different Electrolytes, Jing-Jing Liu, Wei-Hua Qiu, Ling-Yan Yu, Hai-Lei Zhao, Tao Li

Journal of Electrochemistry

Cathode materials LiNi1/3Co1/3Mn1/3O2 were prepared by low-heating solid-state reaction.The micro-structure and morphology of as-synthesized materials have been investigated by using XRD and SEM. The compatibilities of LiNi1/3Co1/3Mn1/3O2 with purchased LiPF6/ EC+DMC+DEC electrolyte and prepared LiBOB/EC+DEC+EMC electrolyte have also been studied. The Li/LiNi1/3Co1/3Mn1/3O2 batteries showed excellent electrochemical properties in the LiPF6/EC+DMC+DEC electrolyte. Reversible discharge capacities of 167, 163, 163, 157, 147mAh/g at 0.5C, 1C, 1.5C, 2C, 3C rate between 2.7~4.35 V, with stable cycling performances have …

Go to article

Electrochemical Behavior Of Buprofezin On Glass-Carbon Electrode, Qi Wang, Chang-Guo Chen Nov 2006

Electrochemical Behavior Of Buprofezin On Glass-Carbon Electrode, Qi Wang, Chang-Guo Chen

Journal of Electrochemistry

Electrochemical behavior of Bup has been investigated by means of cyclic voltammetry,linear sweep voltammetry,differential pulse voltammetry and square wave voltammetry.The results indicate that the electrochemical behavior of Bup on the surface of glassy carbon electrode is corresponding to a irreversible two-protons and two-electrons process with absrption.The square wave voltammetry for determination of Bup in actual samples has been established.

Go to article

Fabrication And Characterization Of Gadolinium Hexacyanoferrate Modified Electrode, Yan-Mao Shi, Pan Du, Ping Wu, Yao-Ming Zhou, Chen-Xin Cai Nov 2006

Fabrication And Characterization Of Gadolinium Hexacyanoferrate Modified Electrode, Yan-Mao Shi, Pan Du, Ping Wu, Yao-Ming Zhou, Chen-Xin Cai

Journal of Electrochemistry

A new electroactive polynuclear inorganic compound of rare earth metal hexacyanoferrate,gadolinium hexacyanoferrate(GdCHF),was prepared by electrochemically deposition on the surface of a glassy carbon electrode with a potential cycling procedure.The result of SEM indicated that the GdHCF was in the form of particles adhered on the surface of electrode.There were two different shapes and sizes of GdHCF forming on the surface of electrode.FTIR spectrum of GdHCF showed a very strong and sharp peak,which located at 2062.5 cm-1 and corresponded to the stretching vibration of the C≡N group in the GdHCF.The cyclic voltammetric results indicated that the GdHCF/GC electrode exhibited two …

Go to article

Synthesis Of Monolithic Carbon/Nickel Oxide Composite Electrode Material And Cyclic Voltammetry Characteristics, Tian-Ying Guo, Jing-Wei Zhu, Mou-Dao Song, Bang-Hua Zhang Nov 2006

Synthesis Of Monolithic Carbon/Nickel Oxide Composite Electrode Material And Cyclic Voltammetry Characteristics, Tian-Ying Guo, Jing-Wei Zhu, Mou-Dao Song, Bang-Hua Zhang

Journal of Electrochemistry

Monolithic carbon/nickel oxide composite materials were synthesized by carbonization of phenol formaldehyde gels that were ion-exchanged with Ni2+.Atomic absorption spectroscopy and powder X-ray diffraction technique were used to characterize the chemical composition and physical structure of the materials.The nickel dope amount for this method can reach 5.9 %(by mass).Subsequent cyclic voltammetry experiments indicate that the materials exhibit best capacitive performance at the nickel content of 4.4 %.

Go to article

Fabrication Of Gold Electrode Array Based On Co2 Laser Ablation, Wei Zhang, Jiang-Qun Xiao, Yong-Liang Zhou Nov 2006

Fabrication Of Gold Electrode Array Based On Co2 Laser Ablation, Wei Zhang, Jiang-Qun Xiao, Yong-Liang Zhou

Journal of Electrochemistry

A rapid process is described to produce single or multiple electrodes of any shape based on CO2 laser ablation for microfluidic chip.The method is as follow: coating a kind of material as sacrifice layer on a piece of glass with sputtered Cr and Au;designing the needed pattern on a computer;selecting proper parameters and ablating with CO2 laser;wiping of Au/Cr and sacrifice layer,and obtain electrodes at last.The microfluidic chip was gotten by reversely bonding with a piece of PDMS,and sealing around with PDMS prepolymer.The mask' effect is the main factor that influencing electrode quality.The width of electrodes could be …

Go to article

Novel Electrochemical Method For Synthesis Of Nanostructured Materials Of Noble Metals Based On Poly(N-Vinylpyrrolidone) (Pvp), Wei Pan, Xiao-Kai Zhang, Ming-Hu Huang, Shao-Xin Huang, Xing-Li Feng, Hou-Yi Ma Nov 2006

Novel Electrochemical Method For Synthesis Of Nanostructured Materials Of Noble Metals Based On Poly(N-Vinylpyrrolidone) (Pvp), Wei Pan, Xiao-Kai Zhang, Ming-Hu Huang, Shao-Xin Huang, Xing-Li Feng, Hou-Yi Ma

Journal of Electrochemistry

Gold nanocrystals with controllable size were synthesized through a simple electroreduction method using poly(N-vinylpyrrolidone)(PVP) of different polymerization degree as both stabilizer and shape-controller for gold nanoclusters.Individual gold nanoparticles spontaneously assembled into the wire-and ring-shaped nanoparticle aggregates depending on the PVP's dynamic stretching and curling,and precursor nanoparticles grew into flat,single-crystalline nanoprisms with thickness of dozens of nanometers based on the oriented aggregation between particles.Besides,core-shell Au/Ag nanoparticles were conveniently synthesized through two-step electroreduction of noble metal ions in the presence of PVPK30.The electrochemical synthetic method based on PVP provides a new path for preparation of noble metal nanostructured materials with different shape …

Go to article

Study Of The Electrooxidation Of Glycerol On Oxide And Pd/C Composite Catalysts, Zhi-Yuan Yan, Chang-Wei Xu, Pei-Kang Shen Nov 2006

Study Of The Electrooxidation Of Glycerol On Oxide And Pd/C Composite Catalysts, Zhi-Yuan Yan, Chang-Wei Xu, Pei-Kang Shen

Journal of Electrochemistry

Oxide and Pd on carbon composite catalysts have been prepared by intermittent microwave heating(IMH) method.The performance of the catalysts for glycerol oxidation in alkaline solution is studied by electrochemical techniques.It is shown that the Pd/C catalyst is active for glycerol electrooxidation.However,the oxide-Pd/C catalysts are even better in terms of the onset potential that is more negative and peak current density.The ratio of oxide to Pd is optimized according to the electrochemical measurement.The results reveal that the addition of oxide into the Pd/C induces the synergistic effect for glycerol electrooxidation.

Go to article

Deep Treatment Of Pulping Wastewater Using Three Phase Fluidized Bed Electrode Reactor, Dan Wu, Qi-Cai Shi, Ji-Ti Zhou, Bao-Jun Jia Nov 2006

Deep Treatment Of Pulping Wastewater Using Three Phase Fluidized Bed Electrode Reactor, Dan Wu, Qi-Cai Shi, Ji-Ti Zhou, Bao-Jun Jia

Journal of Electrochemistry

Treatment of pulping wastewater by using a novel electrochemical reactor,i.e.the three phase fluidized bed electrode,reactor were invesigated.The effects of air flow rate,applied voltage,pH value and FeSO4 concentration on electrolysis efficiency were investigated.It was clearly shown that the 20 V of voltage,0.3 m3·h-1 of air flow rate,1000 mg L-1 of FeSO4 concentration and pH≈2.5 were its best conditions.COD removal could be 70.1% under these conditions.

Go to article

Electrochemical Properties Of The Modified Carbon Nanotubes, Chun-An Ma Nov 2006

Electrochemical Properties Of The Modified Carbon Nanotubes, Chun-An Ma

Journal of Electrochemistry

Powder micro-electrodes were prepared from raw carbon nanotubes and carbon nanotubes modified by carboxyl.The electro-reduction properties of both the raw and open-ended carbon nanotubes in p-Nitrophenol solution were investigated.The FTIR spectrum result indicated that the functional groups are successfully fixed on the surface of the carbon nanotubes after nitric acid treatment.The cyclic voltammetry results show that the electrochemical activity of carboxyl-modified carbon nanotubes was improved.The mechanism of electro-(reduction) for the carbon nanotubes after acid treatment was discussed.

Go to article

Reaction Mechanism Of V(Ⅳ)/V(Ⅴ) Redox Couple At Graphite Felt Composite Electrode Bonded With Conductive Carbon Plastic, Xiao-Gang Li, Ke-Long Huang, Su-Qin Liu, Ning Tan, Li-Quan Chen Nov 2006

Reaction Mechanism Of V(Ⅳ)/V(Ⅴ) Redox Couple At Graphite Felt Composite Electrode Bonded With Conductive Carbon Plastic, Xiao-Gang Li, Ke-Long Huang, Su-Qin Liu, Ning Tan, Li-Quan Chen

Journal of Electrochemistry

The rate-determining step of V(Ⅳ) /V(Ⅴ) redoxreaction was investigated at graphite felt(GF)composite electrode by various techniques: cyclic voltammetry,polarization curve and impedance spectroscopy.Cyclic voltammetry analysis indicated that V(Ⅳ) /V(Ⅴ) redox reaction at GF electrode is quasi reversible.Acertain chemical reaction step is suspected to follow the electron transfer step of this reaction.The Tafel slopevalue(0.124) obtained from the polarization curve agrees well with theoretical value(0.12),which supposingthe electron transfer step was the rate-determining step.Impedance Spectroscopies at various potentials werestudied and simulated by equivalentcircuits.The impedance value of the electron transfer step modified is greatlyhigher than the others,which shows that the electron transfer step is the …

Go to article

The Synthesis, Structure And Electrochemical Performances Of Lithium Iron Phosphate, Hui Xie, Zhen-Tao Zhou Nov 2006

The Synthesis, Structure And Electrochemical Performances Of Lithium Iron Phosphate, Hui Xie, Zhen-Tao Zhou

Journal of Electrochemistry

The lithium iron phosphate cathode materials were synthesized by solid-state reaction combined high-rate ball milling under the temperature ranging from 400 ℃ to 700 ℃.The crystalline structure, morphology of particles, and electrochemical performance of the sample were investigated by X-ray diffraction, scanning electron microscopy and charge-discharge test. The results showed that the sintering temperature had great influences on the crystal structure, morphology and electrochemical performances of LiFePO4. The sample synthesized under 600℃ showed the best charge-discharge performances with the first specific discharge capacity of(128.8) mAh/g and the 15th specific discharge capacity of 129.1 mAh/g at 0.1C rate, …

Go to article

Structure And Electrochemical Characteristics Of Lifepo4 Prepared By The Polyacrylates-Pyrolysis-Reduction Method For Li-Ion Batteries, Li-Hong Yu, Yu-Liang Cao, Xiao-Fei Zhang, Han-Xi Yang, Xin-Ping Ai Nov 2006

Structure And Electrochemical Characteristics Of Lifepo4 Prepared By The Polyacrylates-Pyrolysis-Reduction Method For Li-Ion Batteries, Li-Hong Yu, Yu-Liang Cao, Xiao-Fei Zhang, Han-Xi Yang, Xin-Ping Ai

Journal of Electrochemistry

The cathode material of olivine LiFePO4 was prepared by a novel method of polyacrylate-pyrolysis-reduction.XRD demonstrates that the material have the olivine structure.SEM photo shows an average particle-size of about 100 nm with a well distribution.Electrochemical test of cycling at a constant current reveals the discharge capacity of 138 mAh/g and a good cycling stability.It is a novel practicable technology to prepare LiFePO4 by using polyacrylate-pyrolysis-reduction method.

Go to article

Some Aspects Of The Mechanical Response Of Pmr-15 Neat Resin At 288°C: Experiment And Modeling, Christina M. Falcone Sep 2006

Some Aspects Of The Mechanical Response Of Pmr-15 Neat Resin At 288°C: Experiment And Modeling, Christina M. Falcone

Theses and Dissertations

The mechanical response of PMR-15 neat resin was investigated at 288?C. Monotonic loading/unloading tests performed at several constant stress rates revealed considerable rate dependence, especially on the unloading path. Effect of prior stress rate on creep behavior was evaluated in creep tests preceded by uninterrupted loading to a target stress. Creep response was dependent on the prior stress rate. Effect of loading history was studied in stepwise creep tests, where specimens were subjected to a constant stress rate loading followed by unloading to zero stress with intermittent creep periods during both loading and unloading. Comparison of creep strains accumulated during …

Go to article

Effects Of Polishing Shot-Peened Surfaces On Fretting Fatigue Behavior Of Ti-6al-4v, Kasey S. Scheel Sep 2006

Effects Of Polishing Shot-Peened Surfaces On Fretting Fatigue Behavior Of Ti-6al-4v, Kasey S. Scheel

Theses and Dissertations

The research of this thesis was done to investigate the effects of polishing a shot-peened specimen of Ti-6Al-4V on the fretting fatigue life of that specimen. The shot-peening process, though one of the most beneficial techniques in prolonging fretting fatigue life, creates a textured surface that may lead to problems on the micro level. This research was done in an attempt to further improve the peening process by examining the effects of another surface treatment to be used in conjunction, surface polishing. The rough peened surface may contain abrupt changes in surface geometry that act as stress risers, which are …

Go to article

Effects Of Phase Difference Between Axial And Contact Loads On Fretting Fatigue Behavior Of Titanium Alloy, Mohammad Almajali Sep 2006

Effects Of Phase Difference Between Axial And Contact Loads On Fretting Fatigue Behavior Of Titanium Alloy, Mohammad Almajali

Theses and Dissertations

Fretting fatigue is the surface damage that occurs at the interface between two components that are undergoing a small amplitude oscillatory movements. It results in a reduction of the material life as compared to the plain fatigue. Most of the previous works were accomplished under a constant applied normal load and a little effort was done under a variable contact load, while none of these studies has considered the phase difference between the axial load and the contact load. The primary goal of this study is to investigate the effect of phase difference between axial and contact loads on fretting …

Go to article

Rate Dependence Of Tensile Properties And Stress-Strain Behavior Of An Oxide/Oxide Ceramic Matrix Composite At Elevated Temperature And The Effects Of Low-Magnitude Sustained Loading On Composite Microstructure, Andrew T. Radzicki Sep 2006

Rate Dependence Of Tensile Properties And Stress-Strain Behavior Of An Oxide/Oxide Ceramic Matrix Composite At Elevated Temperature And The Effects Of Low-Magnitude Sustained Loading On Composite Microstructure, Andrew T. Radzicki

Theses and Dissertations

Advanced aerospace structures and components require materials that exhibit high strength at high operating temperatures. Nextel ™ 720/Alumina (N720/A) is an oxide/oxide, porous-matrix ceramic-matrix composite developed for load bearing applications at elevated temperatures. The current research investigates the rate dependence of tensile properties of the N720/A CMC at 1200°C as well as the creep behavior of this composite under applied stresses in the 1-25 MPa range. In addition, influence of prior loading rate on the creep response of N720/A under applied stresses above 50 MPa was evaluated at 1200°C. Tensile tests conducted at loading rate of 0.0025 and 25 MPa/s …

Go to article

Effects Of Environment On Creep Behavior Of Two Oxide-Oxide Ceramic Matrix Composites At 1200°C, Pavlos Koutsoukos Sep 2006

Effects Of Environment On Creep Behavior Of Two Oxide-Oxide Ceramic Matrix Composites At 1200°C, Pavlos Koutsoukos

Theses and Dissertations

Previous studies by the advisor and graduate students examined creep behavior of the Nextel720/Alumina CMC in air and in 100% steam environments at 1200 and 1330°C. Results showed that while this oxide/oxide system exhibits an exceptionally high fatigue limit at 1200°C it also experiences substantial strain accumulation under sustained loading conditions. Furthermore, these earlier investigations revealed a significant degrading effect of 100% steam environment on material performance under both static and cyclic loadings. The present effort will investigate creep rupture behavior of Nextel720/Alumina composite in the inert gas environment. In addition, creep rupture behavior of Nextel720/Aluminosilicate CMC will be investigated …

Go to article

Research Of Explosion Mechanism Of Lithium-Ion Battery, Yu-Hong Chen, Zhi-Yuan Tang, Yan-Bing He, Qiang Liu Aug 2006

Research Of Explosion Mechanism Of Lithium-Ion Battery, Yu-Hong Chen, Zhi-Yuan Tang, Yan-Bing He, Qiang Liu

Journal of Electrochemistry

The heat character of Lithium-ion battery materials and explosion mechanism of Lithium-ion cells under the overcharge,short-circuit and other abuse behavior are tested by C80 calorimeter, DSC and charge-discharge instrument.SEI reactions, LixC6/electrolyte and LixC6/PVDF reactions take place at the anodes. Electrolyte and solvent reactions happen after 178℃ and Li1-xCo1/3Ni1/3Mn1/3O2 decomposes after 230℃. The batteries explode at 150℃ oven test or 1.5C, 5.5 V overcharge and do not explode at short-circuit.

Go to article

Studies On Performance And Electrode Materials For All Vanadium Flow Battery, Jun Yuan, Qing-Chun Yu, Yi-Feng Liu, Liang-Liang Ma, Yi-Hua Wu Aug 2006

Studies On Performance And Electrode Materials For All Vanadium Flow Battery, Jun Yuan, Qing-Chun Yu, Yi-Feng Liu, Liang-Liang Ma, Yi-Hua Wu

Journal of Electrochemistry

In this paper,cyclic voltammetry has been used to study the electrochemical performance of the treated and untreated graphite,soft graphite and PAN-carbon cloth in vanadium sulfate solution.The results show that: the reversibility of reaction can be improved on the surface of treated electrode,and the current can also increase;the electrochemical performance of treated electrode is remarkably enhanced;in the process of charge/discharge,the charge current can reach up to 20 mA/cm2,and discharge current up to 15 mA/cm2;surface morphology of the treated and untreated graphite show that the treatment can change the surface structure of electrode and also add the reaction …

Go to article

Immobilization Of Cytochrome C On The Surface Of Single-Wall Carbon Nanotube And Its Direct Electron Transfer And Electrocatalysis, Ya-Jing Yin, Ya-Fen Lv, Ping Wu, Pan Du, Yan-Mao Shi, Chen-Xin Cai Aug 2006

Immobilization Of Cytochrome C On The Surface Of Single-Wall Carbon Nanotube And Its Direct Electron Transfer And Electrocatalysis, Ya-Jing Yin, Ya-Fen Lv, Ping Wu, Pan Du, Yan-Mao Shi, Chen-Xin Cai

Journal of Electrochemistry

Cytochrome c(Cyto c) was immobilized on the surface of the single-wall carbon nanotube(SWNT) by using the method of adsorption.Infrared spectroscopy indicated that the Cyto c remained in its original structure and did not undergo structural change after its immobilization on the SWNT.The direct electrochemistry of cyto c,which was adsorbed on the surface of the SWNT,was studied by cyclic voltammetry.The voltammetric results demonstrated that the SWNT had promoting effects on the direct electron transfer of Cyto c and also indicated that the immobilized Cyto c retained its bioelectrocatalytic activity to the reduction of H2O2.This modified electrode might …

Go to article

Investigation Of The Direct Electrochemical Reduction Of Cr2O3 Powder In Molten Cacl2 By A Metallic Cavity Electrode, Guo-Hong Qiu, Di-Hua Wang, Xian-Bo Jin, Xiao-Hong Hu, Zheng Chen Aug 2006

Investigation Of The Direct Electrochemical Reduction Of Cr2O3 Powder In Molten Cacl2 By A Metallic Cavity Electrode, Guo-Hong Qiu, Di-Hua Wang, Xian-Bo Jin, Xiao-Hong Hu, Zheng Chen

Journal of Electrochemistry

A metallic cavity electrode is used for further investigation of the electrochemical behaviour of Cr2O3 powder in molten CaCl2(Na: ~0.02% by mass,Mg: < 0.005% by mass) at 900 ℃.The Cr2O3 powder reduction mechanism was confirmed in line with EDX and SEM analysis of the potentiostatic electrolysis products.The correlations between the particle size of metallised product and the electrolysis potential,or electrolysis time were analysed.

Go to article

Studies On Synthesis And Electrochemical Performance Of LiXNi1/3Mn1/3Co1/3O2 As Cathode Material For Lithium Ion Batteries, Xiao-Jian Guo, Jie Li, Yi-Xiao Li, Yong Yang Aug 2006

Studies On Synthesis And Electrochemical Performance Of LiXNi1/3Mn1/3Co1/3O2 As Cathode Material For Lithium Ion Batteries, Xiao-Jian Guo, Jie Li, Yi-Xiao Li, Yong Yang

Journal of Electrochemistry

A series of LiNi1/3Mn1/3Co1/3O2 were synthesized by a combined hydroxides coprecipitation and calcination method.Effects of synthesizing temperature of coprecipitations and the Li∶M ratios on structure and electrochemical performance of the materials were studied.The results showed that materials synthesized with coprecipitation at room temperature(~20 ~(o)C) delivered the best electrochemical performance.Another series of cathode materials LiXNi1/3Mn1/3Co1/3O2 with different Li∶M ratios were synthesized with this method.The results showed that sintering at high temperature could cause loss of LiOH,thus more LiOH should be added.It is demonstrated that Li …

Go to article

Pre-Oxidative Amperometric Glucose Biosensor Incorporated With Carbon Nanotube And Pbo2, Hong-Lan Qi, Cheng-Xiao Zhang Aug 2006

Pre-Oxidative Amperometric Glucose Biosensor Incorporated With Carbon Nanotube And Pbo2, Hong-Lan Qi, Cheng-Xiao Zhang

Journal of Electrochemistry

A pre-oxidative amperometric glucose biosensor incorporated with carbon nanotube,ferrocenemonocarboxylic acid and PbO2 was designed.The interferences coming from reduced substances,such as ascoribic acid and urine acid were eliminated by PbO2.The oxidative current is linear at the potential of +0.40 V(vs.SCE) to the concentration of glucose in the range from 0.50 to 20 mmol·L-1,and the detection limit of glucose is 0.1 mol L-1.The relative standard deviation is 3.3% for seven successive assays at 5.0 mmol·L-1glucose.This biosensors have been applied to determination of the glucose in serum with satisfying results.

Go to article

Investigations On Electrochemical Characteristics Of Liv3O8 Electrode In Lithium Sulfate-Water-Ethanol Electrolytes, An-Bao Yuan, Wei-Xiang Song Aug 2006

Investigations On Electrochemical Characteristics Of Liv3O8 Electrode In Lithium Sulfate-Water-Ethanol Electrolytes, An-Bao Yuan, Wei-Xiang Song

Journal of Electrochemistry

The active material of LiV3O8 prepared using low-temperature pre-reaction in solution followed by intermediate-temperature calcination at 450 ℃.The product was characterized by X-ray diffraction analysis and scanning electron microscope observation.The performance of LiV3O8  electrode in neutral lithium sulfate-water-ethanol electrolytes was investigated using electrochemical methods.Galvanostatic charge/discharge results indicated that the specific capacity of LiV3O8  electrode decreases with ethanol content increasing in electrolyte.The most appropriate water/ethanol volumetric ratio is 4 ∶1 in terms of conductivity of the electrolyte and stability of the electrode.AC impedance measurements demonstrated that the ohmic resistance of the electrolyte …

Go to article

The Influence Of Pva As Disperser On Lifepo4 Synthesized By Hydrothermal Reaction, Hui-Lin Li, Hui Zhan, Yu-Hong Zhou Aug 2006

The Influence Of Pva As Disperser On Lifepo4 Synthesized By Hydrothermal Reaction, Hui-Lin Li, Hui Zhan, Yu-Hong Zhou

Journal of Electrochemistry

LiFePO4 was synthesized by means of hydrothermal reaction,in which PVA acts as disperser and glucose as carbon source. The samples were characterized by X-ray diffraction, scanning electron microscopy and electrochemical measurement. SEM results show that the sample is homogeneously composed of grains with a particle size of ca.200nm. In the charge/discharge test, the products exhibited a 3.45V discharge voltage plateau and a maximum specific capacity of 140mAh/g. After 40 cycles, its capacity only declined by 2.1%. Besides these, the mechanism for the influence of the particle size and carbon coating on the electrochemical property of LiFePO4 material was …

Go to article

Calcined Temperatures Influence On Synthesis And Electrochemistry Charactarization Of Li[Ni0.475Mn0.475Co0.05]O2 For Li-Ion Batteries, Li-Qin Wang, Li-Fang Jiao, Hua-Tang Yuan, Yong-Mei Wang Aug 2006

Calcined Temperatures Influence On Synthesis And Electrochemistry Charactarization Of Li[Ni0.475Mn0.475Co0.05]O2 For Li-Ion Batteries, Li-Qin Wang, Li-Fang Jiao, Hua-Tang Yuan, Yong-Mei Wang

Journal of Electrochemistry

Layered Li[Ni0.475Mn0.475Co0.05]O2 materials have been prepared by a solid-state pyrolysis method.Experiments of XRD,SEM,cyclic voltammetry and charge/discharge cycling were carried out.It can be learned that when calclined at 800 ℃,the sample showed the highest first discharge capacity of 178.8 mAh·g-1 at a current density of 20 mA/g in the voltage range 2.3~4.6 V

Go to article

Study On The Microstructure Of Pb-Sn Alloy Obtained From Quasi-Two-Dimensional Electrodeposition, Bin Sun Aug 2006

Study On The Microstructure Of Pb-Sn Alloy Obtained From Quasi-Two-Dimensional Electrodeposition, Bin Sun

Journal of Electrochemistry

A two-layered structure of eutectic-solid sulotion is formed in the microstructure of Pb-Sn alloy obtained from quasi-two-dimensional electrodeposition.It is showed that this unique structure is caused by the variation of the current density on the growth interface.When the interface is located in the front of the whole deposits,the current density is high.So the Pb and Sn can deposit together and the eutectic texture forms.When the interface is in the rear of the whole deposits,the current density is low.At this moment the electrodeposition of Pb is the dominant reaction,and the Pb-based solid solution appears.

Go to article

Investigation On The Resistance To Electrochemical Oxidation Of Carbon Nanotubes With Various Diameters, Yu-Yan Shao, Ge-Ping Yin, Yun-Zhi Gao, Peng-Fei Shi Aug 2006

Investigation On The Resistance To Electrochemical Oxidation Of Carbon Nanotubes With Various Diameters, Yu-Yan Shao, Ge-Ping Yin, Yun-Zhi Gao, Peng-Fei Shi

Journal of Electrochemistry

The resistance to electrochemical oxidation of multi-wall carbon nanotubes(CNT) with various diameters is investigated by applying a fixed potential of 1.2 V(RHE) for 120 h in 0.5 mol L-1 H2SO4.The oxidation current of CNTs decreases with their diameters,but CNTs between 10~20 nm in diameter(D1020) shows the lowest oxidation current.XPS analysis shows that,after oxidation,the increase in surface oxygen for D1020 is the smallest,implying that the oxidation degree for D1020 is the lowest.The conclusion can be reached that CNTs between 10~20 nm in diameter are the most resistant to electrochemical oxidation.The difference in electrochemical stability of CNTs …

Go to article

Voltammetric Behavior And Its Determination Of Acetaminophen At Poly (Congo Red) Modified Electrode, Hong-Bin Luo, Ya-Feng Zhang, Wei Chen, Xin-Hua Lin, Xiao-Yan Lin Aug 2006

Voltammetric Behavior And Its Determination Of Acetaminophen At Poly (Congo Red) Modified Electrode, Hong-Bin Luo, Ya-Feng Zhang, Wei Chen, Xin-Hua Lin, Xiao-Yan Lin

Journal of Electrochemistry

Cyclic voltammetry was used to prepare poly(Congo Red) film on glassy carbon electrode and to study the electrochemical behavior of acetaminophen on poly(congo red) modified electrode.Experimental resultal shows that the poly(congo red) modified electrode exhibits excellent electrocatalytic effect on the oxidation of acetaminophen.The peak currents of linear sweep voltammogram are linear to the acetaminophen concentrations over the range of 2.0×10-7～2.0×10-6 mol·L-1.The detection limit has been estimated to be 4.0×10-8 mol·L-1.This method can be used for the determination of acetaminophenin real sample.

Go to article

Preparation And Supercapacitor Properties Of Yttrium Doped Nio, Dan-Dan Han, Ye Chen, Mi-Lin Zhang, Chang Shu, Chun-Xia Zhang, Peng-Cheng Xu Aug 2006

Preparation And Supercapacitor Properties Of Yttrium Doped Nio, Dan-Dan Han, Ye Chen, Mi-Lin Zhang, Chang Shu, Chun-Xia Zhang, Peng-Cheng Xu

Journal of Electrochemistry

Yttrium doped Nano-NiO were synthesized by chemical precipitation method.Characterization and performance of the samples were studied by X-ray diffraction,the results showed that the doping Yttrium did not change the crystal structure of NiO,but the size of crystalline grain was reduced.The electrochemical properties of the electrode materials were measured in the three electrode system.Electrochemical properties of NiO were researched by cyclic voltammetry,constant current charge/discharge and AC impedance methods.It could be seen that the chemical doping improved the specific capacitance and the utilization of active materials.When the weight ratio of NiO with Y2O3was 1∶0.1,the composite material had the …

Go to article

First Prev Next Last