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

Power and Energy Commons™

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

2006

Discipline
Institution
Keyword
Publication
Publication Type

Articles 1 - 30 of 54

Full-Text Articles in Power and Energy

2006 Fall Engr333 Project Final Report, 2006 Fall Engr333 Dec 2006

2006 Fall Engr333 Project Final Report, 2006 Fall Engr333

ENGR 333

The objective of this project was to demonstrate Calvin’s interest in alternative energy. The development of a short-term plan to implement a demonstration wind turbine and a long-term plan to determine the feasibility of a larger turbine for the future demonstrates this interest. The class was divided into five teams: management, external relations, long-term technology, short-term technology, and campus infrastructure. While each team had its own objectives, everyone worked together to share information and accomplish the overall project goals. This management technique provided necessary structure and simulated an environment typically found in a career environment.


2006 Fall Engr333 Project Posters, 2006 Fall Engr333 Nov 2006

2006 Fall Engr333 Project Posters, 2006 Fall Engr333

ENGR 333

To demonstrate Calvin’s interest in alternative energy by developing a short-term plan to implement a demonstration wind turbine and a long-term plan to determine the feasibility of a larger turbine for the future.


Synergistic Functions Of Trimethl Phosphate And Vinylene Carbonate As Additives For The Li-Ion Batteries, Zhi-Yuan Tang, Yan-Bing He, Quan-Sheng Song, Yu-Hong Chen, Yuan-Gang Liu, Qiang Liu Nov 2006

Synergistic Functions Of Trimethl Phosphate And Vinylene Carbonate As Additives For The Li-Ion Batteries, Zhi-Yuan Tang, Yan-Bing He, Quan-Sheng Song, Yu-Hong Chen, Yuan-Gang Liu, Qiang Liu

Journal of Electrochemistry

The cooperative effects of trimethl phosphate and vinylene carbonate as additives for Li-ion batteries are investigated by using the cyclic voltammetry,electrochemical impedance spectroscopy and scanning electronic micro-photographs.The results show that the combination application of TMP and VC as additives for Li-ion batteries not only enhances safety of the batteries,but also improves their cycling performance.The reason may be ascribed to firstly VC being reduced and the reduction product polymerized to form excellent solid electrolyte interface(SEI) layer on the surface of graphite electrode during the first charge and discharge process,which prevents effectively the decomposition of TMP on the surface of the graphite …


Facilitated Effect Of Ag To Oxygen Transportation In Pem Fuel Cell Air Cathodes, Hong-Feng Xu, Jian-Hua Dong, Xiang-Li Hou Nov 2006

Facilitated Effect Of Ag To Oxygen Transportation In Pem Fuel Cell Air Cathodes, Hong-Feng Xu, Jian-Hua Dong, Xiang-Li Hou

Journal of Electrochemistry

Silver(Ag) was deposited in the pores of Nafion membrane by ion exchange and succedent hydrogen reduction;the structures of Nafion-Ag membrane were measured by TEM and XRD,the diffusion coefficients of oxygen in Nafion-Ag was determined by electrochemical limited current method.The results showed that after deposited silver,the pores in the Nafion were enlarged by silver grains;the oxygen diffusion coefficient was increased about four times.By introducing silver in the thin Nafion film around the cathode catalyst,the performance of PEM fuel cell have a evident increasing in high current density, which shows the facilitated effects of silver to oxygen transportation in PEM fuel cell.


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.


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 %.


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 …


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.


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.


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 …


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, …


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.


2006 Fall Engr333 Project Assignment, Matthew K. Heun Sep 2006

2006 Fall Engr333 Project Assignment, Matthew K. Heun

ENGR 333

In the Fall 2006 semester, I challenged the ENGR333 students to “construct a realistic plan to make a significant impact on the Calvin College campus with electrical power generated from wind resources.”

Customer

The customer for this project was Calvin’s VP for finance Henry DeVries.


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.


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 …


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 …


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.


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 …


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.


Recycling Of The Spent Nickel-Cadmium Batteries Based On Bioleaching Process, Liang-Shu Xia, Shi-Fu Fu, Zhong-Qing Chen Aug 2006

Recycling Of The Spent Nickel-Cadmium Batteries Based On Bioleaching Process, Liang-Shu Xia, Shi-Fu Fu, Zhong-Qing Chen

Journal of Electrochemistry

Less than 1 percent of discarded dry batteries are recovered in china.it is necessary to find an economic,fast and environmentally friendly process to recycle spent dry batteries.Bioleaching is better one of the few technology applied for the recovery of the toxic metals from hazardous spent batteries.In this study,after the acidified sludge made by the inoculated and cultured indigenous sewage sludge was acted as leaching bacteria species,the influence of the different pH values,the different residence time of the sludge in bioreactor(RTB),the leaching time,whether or not adding Fe(iron powder) to the leaching liquid on the leaching rate of Ni,Cd was tested.The results …


Electrochemical Behavior Of Electrolytic Manganese Dioxide In Mgso4 Solution, Dan-Mei Yu, Yu-Jun Si, Chang-Guo Chen, Yu-Ping Liu, Yan Liu Aug 2006

Electrochemical Behavior Of Electrolytic Manganese Dioxide In Mgso4 Solution, Dan-Mei Yu, Yu-Jun Si, Chang-Guo Chen, Yu-Ping Liu, Yan Liu

Journal of Electrochemistry

The rechargeability and crystal structure changing of electrolytic manganese dioxide(EMD) in MgSO4 electrolyte were investigated by cyclic voltammetry,galvanostatic charge/discharge and X-ray diffraction.The results have shown that the EMD has good rechargeability;after several initial cycles,the charge and discharge became stability;after discharge,the γ-MnO2 structure of EMD was changed,the production was reversible and could be recharged to γ-MnO2 structure again which ensured the rechargeability of EMD.


The Property Study Of Libob-Pc/Dec Electrolyte, Ying-Kun Ning, Bi-Tao Yu, Fu-Shen Li, Wei-Hua Qiu Aug 2006

The Property Study Of Libob-Pc/Dec Electrolyte, Ying-Kun Ning, Bi-Tao Yu, Fu-Shen Li, Wei-Hua Qiu

Journal of Electrochemistry

The new electrolyte salt LiBOB for Li-ion battery was synthesized in laboratory,and series of electrolytes of LiBOB and PC/DEC was compounded.The conductivity of the electrolytes was compared by changing the temperature and concentration.The cycling performance of charging-discharging was also compared by the charging-discharging test,the results showed that the varying regularity of conductivities and cycling stability and capacity were not always identical,but there were a suitable electrolyte for Li/ARG cell.The A.C.impedance and CV were used to test the compatibility of the most suitable electrolyte and ARG anode.Conclusion can be drawn that the ARG anode can be protected very well by SEI …


Degradation Of P-Nitrophenol Wastewater By Liquid Phase Catalyzed In Bipolar Liquid Bed Cell, Shi-Yuan Guo, Ai-Li Zhang, Ji-Ti Zhou, Dan Wu Aug 2006

Degradation Of P-Nitrophenol Wastewater By Liquid Phase Catalyzed In Bipolar Liquid Bed Cell, Shi-Yuan Guo, Ai-Li Zhang, Ji-Ti Zhou, Dan Wu

Journal of Electrochemistry

This investigation was performed to study the degradation of p-nitrophenol(PNP) in the bipolar liquid bed cell catalyzed by liquid phase.The hydrogen peroxide produced on cathodes with the ferrous generated Fenton's reagent to produce hydroxyl radicals which are very active toward organic compounds to strengthen bipolar liquid bed cell in disposing organic compounds.The effects of cell voltage,ferrous concentration and airflow on the COD and PNP removal efficiency were also studied.When pH=3.0,cell voltage is 30V,ferrous concentration is 500×10-6 and airflow is 0.4 m3/h,higher removal efficiency of the COD and PNP are obtained.


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 …


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 …


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


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 …


Influence Of Crystallinity On The Kinetics Of Li Ion Insertation And Deinsertation In Spinel Limn2O4, Rong-Hua Zeng, Dong-Sheng Lv, Wei-Shan Li Aug 2006

Influence Of Crystallinity On The Kinetics Of Li Ion Insertation And Deinsertation In Spinel Limn2O4, Rong-Hua Zeng, Dong-Sheng Lv, Wei-Shan Li

Journal of Electrochemistry

Two spinel lithium manganese oxides of different crystallinity were prepared by sol-gel process and were studied by using inducfively coupled plasma,X-ray diffraction,scaning electron micrographs,constant charging and discharging,cyclic voltammetry and electrochemical impedance spectrometry,the results show that the sample treated under 700 ℃ has higher crystallinity than the sample treated under 500 ℃,however,the sample with lower crystallinity has higher discharge capacity and better cyclic performance that due to quicker charge exchange speed and quicker diffusion speed of Li-ion.


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 …


Study On The Preparetion And Electrochemical Beavior Of Nitrogen Doped Tetrahedral Amorphous Carbon Electrode, Ke Liu, Guang-Fu Wang, Zheng-Hao Wang Aug 2006

Study On The Preparetion And Electrochemical Beavior Of Nitrogen Doped Tetrahedral Amorphous Carbon Electrode, Ke Liu, Guang-Fu Wang, Zheng-Hao Wang

Journal of Electrochemistry

taC∶N films are a good materials for semiconductor electrodes.But further studies are hampered by the ohmic contact problem,which occurs between the silicon and the lead.By studying the influence of heat treatment on the film's property,it is believed that ohmic contact should be made on the silicon first,and then the film be deposited.A set of taC∶N electrodes with various nitrogen content have been prepared.CV study indicates that the cathodic limits move slowly to positive direction.while the anodic limits are unchanged with the increasing of nitrogen content.As a result,the electrochemical windows get narrow either.