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

Engineering Commons

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

Articles 1171 - 1200 of 1915

Full-Text Articles in Engineering

Charge-Discharge Behaviors And Properties Of A Lab-Scale All-Vanadium Redox-Flow Single Cell, Ping Zhao, Hua-Min Zhang, Yue-Hua Wen, Bao-Lian Yi Feb 2007

Charge-Discharge Behaviors And Properties Of A Lab-Scale All-Vanadium Redox-Flow Single Cell, Ping Zhao, Hua-Min Zhang, Yue-Hua Wen, Bao-Lian Yi

Journal of Electrochemistry

An experimental setup with two external saturated calomel reference electrodes(SCE)and two flow cells was established for flow battery research application.By using this setup,the cell voltage,potentials and open circuit potentials of the positive and negative electrodes for a lab-scale flow battery single cell,could be determined simultaneously during charge-discharge(C-D) cycle test.Then,the ohmic internal resistance drop(iR drop),overpotentials at the negative and positive electrodes of the cell during C-D process,were calculated.The average iR drop accounts for about 74% of the total voltage losses during the C-D cycle at current density of 60 mA·cm-2,suggesting the voltage efficiency(VE) of vanadium redox-flow battery(VRB) single cell with graphite …


Ac Impedance Study On The Bcx Cells, Hong-Hua Ge, Jun Wang, Jing Liu, Guo-Ding Zhou, Yi-Ping Wu, Gang Wu Feb 2007

Ac Impedance Study On The Bcx Cells, Hong-Hua Ge, Jun Wang, Jing Liu, Guo-Ding Zhou, Yi-Ping Wu, Gang Wu

Journal of Electrochemistry

The electrodes in both Li/SOCl2 cells and BCX cells were studied by ac impedance spectroscopy.The results indicate that the resistance of the electrode passive layer increased with the storage time,then became stabilized in both kinds of cells.But the electrode resistance decreased a lot after adding BrCl into the cells.The resistance of the Li electrode decreased about a half to that without BrCl,and the value of the glassy carbon electrode decreased from about 100 kΩ to 2 kΩ.The huge resistance of the glassy carbon electrode indicates that it is the control electrode of the cell.


Diamond-Like-Carbon Film Prepared On Stainless Steel Substrates By Liquid Phase Electrochemical Deposition, Jing-Yong Du, Gui-Feng Zhang, Guo-Qing Li, Xiao-Duo Hou Feb 2007

Diamond-Like-Carbon Film Prepared On Stainless Steel Substrates By Liquid Phase Electrochemical Deposition, Jing-Yong Du, Gui-Feng Zhang, Guo-Qing Li, Xiao-Duo Hou

Journal of Electrochemistry

Diamond-like carbon(DLC) films were deposited on stainless steel substrates at atmospheric pressure and low temperature(60 ℃) by electrolysis in a methanol solution with a pulseddirect current power supply.The morphology and microstructure of the resulting DLC films were analyzed using atomic force microscopy(AFM)、scanning electron microscopy(SEM)、Raman spectroscopy and Fourier transformation infrared spectrometry(FTIR).The experimental results show that the hydrogenated diamond-like carbon filmsare smooth and compact.Raman spectroscopy analysis confirmed the presence of a strongpeak at 1 332.51 cm-1,which is assigned to crystalline diamond.The deposition rate can be enhanced to 0.5 μm/h by adding hydrogenous organic solutions.


Comparison Of The Electrochemical Reactivity Of Electrodes Modified By Carbon Nanotubes With Different Sizes, Guo-Feng Yang, Neng-Qin Jia, Zhi-Yong Wang Feb 2007

Comparison Of The Electrochemical Reactivity Of Electrodes Modified By Carbon Nanotubes With Different Sizes, Guo-Feng Yang, Neng-Qin Jia, Zhi-Yong Wang

Journal of Electrochemistry

The electrochemical activity of multi-walled carbon nanotubes(MWNTs) with different sizes,including four different MWNTs with the same length and different diameter,two different MWNTs with the same diameter and different length has been assessed and compared.The various MWNTs modified electrodes were prepared by immobilizing the suitable amount of MWNTs onto a glassy carbon electrode,and their voltammetric responses to ferricyanide,uric acid and dopamine were examined.The corresponding cyclic voltammetric data was showed that the electrochemical and electrocatalytic activities are depended on the nanotube length.The electrochemical reactivity of short MWNT(S-MWNT) is better than that of long MWNT(L-MWNT),which may be mainly attributed to the existence of …


Effect Of 2,2€²-Dipyridyl And K_4fe(Cn)_6 On Electroless Copper Plating Using Glyoxylic Acid As Reducing Agent, Dan-Dan Shen, Fang-Zu Yang, Hui-Huang Wu Feb 2007

Effect Of 2,2€²-Dipyridyl And K_4fe(Cn)_6 On Electroless Copper Plating Using Glyoxylic Acid As Reducing Agent, Dan-Dan Shen, Fang-Zu Yang, Hui-Huang Wu

Journal of Electrochemistry

The electroless copper plating was studied in a bath consisting of glyoxylic acid as reducing agent,Na2EDTA as complexing agent,both 2,2'-dipyridyl and K4Fe(CN)6 as additives,focused on the influence of the additives on the deposition rate,as well as on the composition,structures and surface morphology of the deposits.It was found that adding an optimum amount of 2,2'-dipyridyl and K4Fe(CN)6 to the bath will not only improve the stability of the bath,but also increase the deposition rate by 100 %.The simultaneous addition of both additives causes the deposits to bright appearance and the change in morphology.The deposits were proved to be polycrystalline copper,in which …


Preparation And Lithium Storage Performance Of Nano-Structural Sno_2/Carbon Nanotubes Composite Electrodes, Hong-Bing Wei, Ling Huang, Xiao-Bin Wu, Fu-Sheng Ke, Jin-Shu Cai, Xiao-Yong Fan, Fang-Zu Yang, Shi-Gang Sun Feb 2007

Preparation And Lithium Storage Performance Of Nano-Structural Sno_2/Carbon Nanotubes Composite Electrodes, Hong-Bing Wei, Ling Huang, Xiao-Bin Wu, Fu-Sheng Ke, Jin-Shu Cai, Xiao-Yong Fan, Fang-Zu Yang, Shi-Gang Sun

Journal of Electrochemistry

The Nano-structural SnO2/Carbon Nanotubes Composites were prepared in a solution of SnCl2,ethylene glycol(EG),purified MWCNTs and sodium dodecyl sulfate(SDS) at 160 ℃.The phase structure and surface morphology of the composites were measured by XRD HRTEM and SEM.The results indicate that there are high dispersions and high loadings of SnO2 nanoparticles on MWCNTs.Electrochemical lithium storage performance was studied preliminarily on the obtained samples.MWCNTs modified with SnO2 nanoparicles were shown to have a higher electrochemical reversible capacity than that of MWCNTs during the charge and discharge process.MWCNTs can accommodate the larger structure strain of the active materials produced during Li-ion insertion and extraction,which …


Electrochemical Characteristics Of La_(0.7-X)Ce_Xmg_(0.3)Ni_(2.4)Co_(0.6)(X=0~0.4)Hydrogen Storage Alloys, Ling-Ling Xiao, Yi-Jing Wang, Yi Liu, Jian-Sheng Cao, Da-Wei Song, Li-Fang Jiao, Hua-Tang Yuan Feb 2007

Electrochemical Characteristics Of La_(0.7-X)Ce_Xmg_(0.3)Ni_(2.4)Co_(0.6)(X=0~0.4)Hydrogen Storage Alloys, Ling-Ling Xiao, Yi-Jing Wang, Yi Liu, Jian-Sheng Cao, Da-Wei Song, Li-Fang Jiao, Hua-Tang Yuan

Journal of Electrochemistry

The effect of partial substitution of Ce for La on the structure and the electrochemical properties of the La0.7-xCexMg0.3Ni2.4Co0.6(x=0~0.4)hydrogen storage alloys have been investigated systematically.The result of X-ray powder diffraction(XRD) show that the alloys are all consisted of the LaNi3 phase and the LaNi5 phase.The maximum discharge capacity is decreased gradually with increase of the Ce contents,but the cycling life is improved obviously.


Electrochemical Oxidation Of The Phenol In The Chloride System, Yong Liu, Dan Liu, Shi-Lin Zhao, Jing-Jing Lai Feb 2007

Electrochemical Oxidation Of The Phenol In The Chloride System, Yong Liu, Dan Liu, Shi-Lin Zhao, Jing-Jing Lai

Journal of Electrochemistry

The Ru-Ir /Ti electrode as cathode to electrolysis the synthetic phenolic wastewater was studied.The effect of the initial chloride concentration on the electrolytic treatment result has been discussed.Experiment result shows that the electrochemical oxidation of phenol suits to one kinetics equation in given electrolytic time.If the initial chloride concentration in wastewater increases,the time of the electrochemical oxidation of phenol can be shorten,in other words the apparent rate constant is greater.the middle matters of electrochemical oxidation of phenol in the chloride system detected out by HPLC and GC-MS is mainly 1-chloro-phenol,4-chloro-phenol,2,4-dichloro-phenol,2,6-dichloro-phenol,2,4,6-trichloro-phenol,all kinds of chlorohydrin,small aliphatic acid,and so on.The final production is …


Mwnts Modified Gc Electrode For Hydrogen Peroxide Determination, Hong-Juan Wang, Chun-Mei Zhou, Hao Yu, Feng Peng, Jin-Kun Fang Feb 2007

Mwnts Modified Gc Electrode For Hydrogen Peroxide Determination, Hong-Juan Wang, Chun-Mei Zhou, Hao Yu, Feng Peng, Jin-Kun Fang

Journal of Electrochemistry

A MWNTs modified GC electrode was constructed successfully to be used to detect hydrogen peroxide.Two methods of maximum anodic current of cyclic voltommogram and chronoamperometry were adopted to measure the concentration of hydrogen peroxide.The results show that the MWCNTs can enlarge the effective surface area of GC electrode and can enormously enhance the electron transfer.The sensitivity and correlation coefficient for hydrogen peroxide detection are 2.84 μA/mmol·L-1,0.997 and 1.5 μA/mmol·L-1,0.971 for cyclic voltammetry and chronoamperometry,respectively.The procedure of the two methods to detect hydrogen peroxide is simple,and the results obtained are satisfied.


Influence Of Electrolyte On The Preparation And Electrocatalytic Properties Of Pt/Gc Electrodes, Sheng-Pei Chen, Yan-Xin Chen, Tao Huang, Xiao-Wen Hou, Shi-Gang Sun Feb 2007

Influence Of Electrolyte On The Preparation And Electrocatalytic Properties Of Pt/Gc Electrodes, Sheng-Pei Chen, Yan-Xin Chen, Tao Huang, Xiao-Wen Hou, Shi-Gang Sun

Journal of Electrochemistry

Influence of electrolyte on the electrocatalytic properties of Pt/GC electrodes for formic acid oxidation were studied by using cyclic voltammetry,SEM and electrochemical in situ FTIR spectroscopy.It has demonstrated that the surfaces of Pt/GC electrodes prepared in H2SO4 (Pt/GC1) or in HClO4(Pt/GC2) are all composed of platinum particles,but which crystals are some differences in size and shape.Diameters of platinum particles on the surface Pt/GC1 are of 100~200 nm,and with spheral shape in the majority.The sizes of platinum particles on the Pt/GC2 electrode are larger in general,part of particles is of cube shape and of diameter about 200 nm,and another part of …


The Influence Of Electrolytic Conditions On Synthesis Of Feo_4~(2-), Yan Zhou, Wei-Hua Yang, Dong-Qin Bi, Ting-Ting Huang, Zhen Sun, Quan-Feng Guo Feb 2007

The Influence Of Electrolytic Conditions On Synthesis Of Feo_4~(2-), Yan Zhou, Wei-Hua Yang, Dong-Qin Bi, Ting-Ting Huang, Zhen Sun, Quan-Feng Guo

Journal of Electrochemistry

The FeO42-was synthesized using iron lattice as anode and the solid K2FeO4 was also prepared.Influence of electrolytic conditions,such as stir,ultrasonic,temperature and current density on the current efficiency were studied.The results showed that preferable ferrate(VI) current yield was obtained in a current density of 10 mA·cm-2,temperature 30℃ and 14 mol/L NaOH as electrolyte under at stirring effect.


Study On The Electrochemical Machining Of Titanium Alloys Tc4 With The Method Of Uniform Design, Mei-Li Zhang, Di Zhu, Zheng-Yang Xu Feb 2007

Study On The Electrochemical Machining Of Titanium Alloys Tc4 With The Method Of Uniform Design, Mei-Li Zhang, Di Zhu, Zheng-Yang Xu

Journal of Electrochemistry

For the electrochemical machining of titanium alloys,a passivating film tends to form on the machining surface,which holdbacks the process of machining;and some corrosive pittings can appear on the non-machining surface,which leading to the poor surface quality.So how to improve the machining surface quality,this is a hot problem in aerospace industries.An experiment plan has been made with the method of uniform design and the variance analysis has been carried out using the result data of the previous experiments.The experimental results show that an excellent machining surface with Ra 0.38 μm would be obtained in the electrolyte of 10% NaCl solution,4% Na2S2O8 …


Fabrication And Performance Of Ni-Scsz Cermet Anode Modified By Coating With Gd_(0.2)Ce_(0.8)O_2 For A Sofc, Ren-Zhu Liu, Bo Huang, Xiao-Feng Ye, Shao-Rong Wang, Jia-Di Cao, Huai-Wen Nie, Ting-Lian Wen Feb 2007

Fabrication And Performance Of Ni-Scsz Cermet Anode Modified By Coating With Gd_(0.2)Ce_(0.8)O_2 For A Sofc, Ren-Zhu Liu, Bo Huang, Xiao-Feng Ye, Shao-Rong Wang, Jia-Di Cao, Huai-Wen Nie, Ting-Lian Wen

Journal of Electrochemistry

A Ni-scandia-stabilized zirconia(Ni-ScSZ) cermet anode modified by coating with nano-sized gadolinium-doped ceria(GDC,Gd0.2Ce0.8O2) was prepared using a simple combustion process for the solid oxide fuel cell(SOFC) running on methane fuel.X-ray diffraction(XRD) and scanning electron microscopy(SEM) indicated that the surface of Ni-ScSZ was coated by nano-sized GDC particles(<100nm).Single cell testing showed that the 2.0%(by mass) GDC-coated Ni-ScSZ anode had better performance.The highest power densities of the cell with this anode were 825 and 848mW/cm2 at 850℃ in humidified hydrogen and methane,respectively,whereas the corresponding values were 584 and 586mW/cm2 for the cell with Ni-ScSZ anode.Electrochemical impedance spectra(EIS) illustrated that the cell with Ni-ScSZ anode exhibited far greater impedances than the cell with 2.0%(by mass) GDC-coated Ni-ScSZ anode.Then the short-term stability for the cells with the Ni-ScSZ and 2.0%(by mass) GDC-coated Ni-ScSZ anodes in 97%CH4/3%H2O at 700℃ was checked over a relative long period of operation.No significant degradation in performance has been observed after 84 h of cell testing when 2.0%(by mass) GDC-coated Ni-ScSZ anode was exposed to 97%CH4/3%H2O at 700 ℃.Very little carbon was detected on the anodes,suggesting that carbon deposition was limited during cell operation.


Effects Of Direct Current Bias Potentials On Lipid Membranes Forming On A Glassy Carbon Electrode, Yu-Hui Li, Hong-Wei Zhang, Gui-Lan Song, Zhan-Jun Zhang, Sheng-Min Cai Feb 2007

Effects Of Direct Current Bias Potentials On Lipid Membranes Forming On A Glassy Carbon Electrode, Yu-Hui Li, Hong-Wei Zhang, Gui-Lan Song, Zhan-Jun Zhang, Sheng-Min Cai

Journal of Electrochemistry

The effects of direct current(DC) bias voltage on the structure of lipid membranes forming on a glassy carbon electrode(GCE) was investigated by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS).The experiment showed that the lipid membranes can be formed with either positive or negative bias potential exerted.When bias voltage was exerted,bilayer lipid membranes tended to form due to the electrostatic interaction between the superficial positive charges on the polarized electrode and the negative charged part of PC.When the positive bias voltage overrun the range,the lacunas on s-BLMs would increase,and the BLMs would be broken.A proper equivalent circuit was nonlinearly fitted,based on the …


Investigations On Edlcs Using Pmma-Based Gel Polymer Electrolytes, Xiang-Li Meng, Jin-Ling Yin, Juan Ren, Bao-Hong Zhang Feb 2007

Investigations On Edlcs Using Pmma-Based Gel Polymer Electrolytes, Xiang-Li Meng, Jin-Ling Yin, Juan Ren, Bao-Hong Zhang

Journal of Electrochemistry

Polymethyl methacrylate(PMMA) based gel polymer electrolytes electrochemical double layer capacitors(GPE-EDLCs) were fabricated by an in situ polymerisatonal method with actived carbon electrodes,using propylene carbonate(PC) and ethylene carbonate(EC) as plasticizer,lithion perchlorate as surporting electrolytes.The ion conductivity values of GPEs were evaluated by AC impedance.The properties of PMMA-based GPEs capacitors were researched by impedance spectrum,cyclic voltammetry,galvanostatic charge-discharge.It showed that the ion conductivities of the PMMA-based gel polymer electrolytes reached to 3.7 mS·cm-1 at ambient tempreture.The working voltage of the capacitors reached to 3.0 V.The specific capacitance of the capacitor was obtained as high as 41.6 F·g-1(I=1 mA·cm-2).The equivalent serial resistance of the …


Variable Frequence Switching Power Supply Used To Aluminum Foil Corrosion, Xiang-Dong Zhuo, Lan Sun, Guo-Qing Qian, Chang-Jian Lin Feb 2007

Variable Frequence Switching Power Supply Used To Aluminum Foil Corrosion, Xiang-Dong Zhuo, Lan Sun, Guo-Qing Qian, Chang-Jian Lin

Journal of Electrochemistry

A new variable frequence and multi-wave power supply used to aluminum foil corrosion is introduced.The switching supply power supply controlled by the microcontroller and Variable Frequence in low band and multi-wave、big power supply controlled by the electronic switch bridge for changing phase were designed.This power supply does not need bulky and cumbersome transformer,and the frequency at lower limit is not limited,even lower than 1Hz.


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, Liusu-Qin Liusu-Qin, 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, Liusu-Qin Liusu-Qin, 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 …


Electrochemical Characterization Of Positive Electrode Material Lini_(1/3)Co_(1/3)Mn_(1/3)O_2 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 Lini_(1/3)Co_(1/3)Mn_(1/3)O_2 In Different Electrolytes, Jing-Jing Liu, Wei-Hua Qiu, Ling-Yan Yu, Hai-Lei Zhao, Tao Li

Journal of Electrochemistry

Cathode materials LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2) 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 LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2) with purchased LiPF_(6)/ EC+DMC+DEC electrolyte and prepared LiBOB/EC+DEC+EMC electrolyte have also been studied.The Li/LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2) batteries showed excellent electrochemical properties in the LiPF_(6)/ 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 been obtained.Comparatively,the specific capacity of 160 mAh/g at 0.5C was obtained in LiBOB/EC+DEC+DEC electrolyte,which was just a little lower than that in the other electrolyte.However,the high rate capability of the materials in LiBOB/EC+DEC+DEC was not as …


The Synthesis,Structure And Electrochemical Performances Of Lithium Iron Phosphate, Hui Xie Nov 2006

The Synthesis,Structure And Electrochemical Performances Of Lithium Iron Phosphate, Hui Xie

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 LiFePO_(4).The sample synthesized under 600℃ showed the best charge-discharge performances with the first specific discharge capacity of(128.8) mAh/g and the 15~(th) specific discharge capacity of 129.1 mAh/g at 0.1C rate,each charge-discharge cycling efficiency being 99.7%.Also the sample showed good …


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 Ni~(2+).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 %.


Deep Treatment Of Pulping Wastewater Using Three Phase Fluidized Bed Electrode Reactor, Dan Wu Nov 2006

Deep Treatment Of Pulping Wastewater Using Three Phase Fluidized Bed Electrode Reactor, Dan Wu

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 FeSO_(4) concentration on electrolysis efficiency were investigated.It was clearly shown that the 20 V of voltage,0.3 m~(3) h~(-1) of air flow rate,1000 mg L~(-1) of FeSO_(4) concentration and pH≈2.5 were its best conditions.COD removal could be 70.1% under these conditions.


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.


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.


Structure And Electrochemical Characteristics Of Lifepo_4 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 Lifepo_4 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 LiFePO_(4) 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 LiFePO_(4) by using polyacrylate-pyrolysis-reduction method.


Stm Tip-Induced Nanostructuring-Replacement Method To Construct Pt Surface Nanostructures, Jin-Gang Wang, Jing Tang, Zhao-Bin Chen, Bing-Wei Mao Nov 2006

Stm Tip-Induced Nanostructuring-Replacement Method To Construct Pt Surface Nanostructures, Jin-Gang Wang, Jing Tang, Zhao-Bin Chen, Bing-Wei Mao

Journal of Electrochemistry

STM tip-induced surface nanostructuring based on "Jump-to-contact" mechanism is a nanostructuring technique that has the highest resolution in aqueous solutions.However,for metals that have high cohesive energy,atoms would transfer from surface to tip instead,which limits the wide application of this technique.In this paper,we present a two-step Nanostructuring-Replacement method to construct metal nanoclusters that cannot be obtained directly via the "Jump-to-contact" mechanism.The method is demonstrated to construct Pt nanoclusters that are of great interest in catalysis and electrocatalysis but cannot be constructed via the "Jump-to-contact" mechanism.Since Cu is the most intensively studied and successful system in the tip-induced nanostructuring,it is utilized as …


Preparation And Electrochemical Property Of Bam Boo-Shaped Silicon Nanotubes, Zeng-Tao Liu, Yan-Peng Fu, Chen Li, Yong Yang Nov 2006

Preparation And Electrochemical Property Of Bam Boo-Shaped Silicon Nanotubes, Zeng-Tao Liu, Yan-Peng Fu, Chen Li, Yong Yang

Journal of Electrochemistry

A novel 1D bamboo-shaped silicon nanotubes was synthesized by chemical vapor deposition with Au catalyst and their electrochemical properties were primarily studied.The results showed that these silicon nanotubes were amorphous with the length about tens micrometer and the diameter about one hundred nanometer.Cyclic voltammetry studies showed that Li ions could intercalate into such silicon nanotubes at two location,i.e.,from the conjoint location and the wall of the hole.Meanwhile,the bamboo-shaped structure could help release the expansion of volume,which is usually serious in the lithium batteries.


Preparation And Electrochemical Characterization Of Anatase Tio_2 Nanotubes, Bin Cao, Jin-Wei Xu, Ling-Hong Ding, Wei-Feng Zhang Nov 2006

Preparation And Electrochemical Characterization Of Anatase Tio_2 Nanotubes, Bin Cao, Jin-Wei Xu, Ling-Hong Ding, Wei-Feng Zhang

Journal of Electrochemistry

Titanium oxide nanotubes were prepared by hydrothermal treatment of anatase-type TiO_(2) powders and NaOH solution in an autoclave.Transmission Electron Microscopy and X-ray Diffraction showed that the product is anatase-type TiO_(2) nanotubes.The constant charge-discharge current and cyclic voltammetry exhibited the TiO_(2) nanotubes have a large initial lithium insertion capacity of 260 mA·h/g and good reversibility.This study indicates that TiO_(2) nanotubes might be a good negative electrode materical for second lithium battery in the future.


Fabrication Of Gold Electrode Array Based On Co_2 Laser Ablation, Wei Zhang, Jiang-Qun Xiao, Yong-Liang Zhou Nov 2006

Fabrication Of Gold Electrode Array Based On Co_2 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 CO_(2) 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 CO_(2) 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 100 μm.Demonstrated …


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 pairs …


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 …