Materials Science and Engineering Commons^™

Studies On The Cathodic Current Efficiency In The Electrodeposition Ni-Psz Gradient Coating, Jun Li, Dianlong Wang, Li Chen, Xinguo Hu

Journal of Electrochemistry

The cathodic current efficiency and the electrochemical behavior in electrodeposition Ni-PSZ gradient coating were investigated by various electrochemical techniques and scanning electron microscope. The results showed that the Ni-PSZ composite coatings can accelerate evolution of hydrogen with the increase of PSZ content. The overpotential of nickel reduction will be increased and that of hydrogen reaction will be reduced in the presence of PSZ particles in electrolyte. The effect of PSZ particles on nickel electrodeposition was preferentially to catalyze the formation of H ads . These all contributed to the lower current efficiency.

Study On Properties Of Magnesium Alloy Electrode With Anodized Film, Yi Chi, Ping Yang, Xiufeng Lin

Journal of Electrochemistry

The corrosion resistance of Mg alloy electrode with anodized film in atmosphere is bigger than that of the Mg alloy electrode with chromate film. The corrosion resisance and voltage delay of such electrode with anodized film in NaCl solution changed with anodizing comdition. The effects of composition, morphology and thickness of the anodized film on the peoperty of Mg alloy electrode are discussed.

Surface Modifications Of Carbon Materials Used As Anode Of Lithium Ion Battery Ⅱ. The Carbon Material With Core Shell Structure And Its Positive Effect On Cell Performance Of Graphite Anode, Shuhua Ma, Hanju Guo, Ji Li, Hongze Liang, Xiabin Jing, Fosong Wang

Journal of Electrochemistry

The carbon powders and film electrode with core shell structure were prepared by carbonization in gas state with using refined coal as shell material and Artificial Graphite and Mesocarbon Microbeads (2 800 ℃) graphite as core material. Galvanostatic charge/discharge measurement showed that both steady charge/discharge capacity and first charge/discharge efficiency were improved. Cyclic voltammetry indicated that the peak at about 0.7 V vs. Li⁺/Li characteristic of decomposition of electrolyte got weakened, and a more compact film was formed. X-ray diffraction measurement suggested the existence of amorphous carbon shell on the carbon powders and carbon film.

A Study On The Electrodeposition Of Palladium And It's Nucleation, Fangzu Yang, Shukai Xu, Shibing Yao, Bingyi Chen, Xueqing Zheng, Xiaohui Zhong, Shaomin Zhou

Journal of Electrochemistry

The electrodeposition and nucleation of palladium are studied in the system of potassium citrate and ammonium oxalate. The results show that, with the additives of XP-4 and XP-7 prepared in our laboratory, a full bright palladium electrodeposits will be obtained in the wide ranges of the cathode current densities 0.5～3.5 A/dm² and temperature 40～60 ℃; the qualities of the thick deposits will be effectively improved by means of pulse current plating. Cyclic voltammograms results show that the division of peaks between anodic and cathodic on the electrode process of palladium will be up to 1.05 V, which shows the …

Studies Of Electrochemical Behaviors Of Cytochrome C On Pretreated Gold Electrode, Jin Luo, Lingling Wu, Shaohua Huang, Zhonghua Lin

Journal of Electrochemistry

The quasi reversible responses of both adsorbed and bulk cytochrome c at the pretreated gold electrode are observed. The adsorption behaviors and reaction kinetics have been studied using in situ FTIR spectroscopy, UV/Vis reflection spectroscopy, voltammetry, AC impedance and potential step methods. The results show that the cytochrome c can irreversibly adsorb on the gold surface in a complete monolayer and the adsorbed layer can mediate the redox reaction of the cytochrome c in the solution in the absence of promoter.

Electrochemical Studies Of Cyanocobalamin On Silver Electrode, Zhai Jin, Yang Pin, Donghong Zheng, Junwei Zheng, Tianhong Lu

Journal of Electrochemistry

The electrochemical characteristics of cyanocobalamin were separately studied on smooth and roughed silver electrode. It was found that the reduction of cyanocobalamin is two one electron steps on roughed silver but one two electron step on smooth electrode. The reason is due to the ability of absorption of the surface of electrode.

The Preparation Of Heteropoly Compound Polypyrrole Film Modified Electrode And Its Electrochemical Properties, Weiqing Wang, Xiumei Zhang, Long Cheng, Baifeng Liu, Shaojun Dong

Journal of Electrochemistry

Electronically conducting polypyrrole doped with heteropolyanions K₁₀H₃[Nd(SiMo₇W₄)₂]·xH₂O(denoted as [Nd(SiMo₇W₄)₂]^13-) was synthesized by electrochemical polymerization. This modified electrode maintains the electrochemical and electrocatalytic properties of heteropolyanion, with having good stability and electrocatalytic activity on the reduction of nitric oxide in acidic aqueous solution.

Surface Modifications Of Carbon Materials Used As Anode Of Lithium Ion Battery Ⅰ. Influences Of Oxidation And Reduction Pretreatment On Anode Performance, Shuhua Ma, Hanju Guo, Ji Li, Hongze Liang, Xiabin Jing, Fosong Wang

Journal of Electrochemistry

The influences of the trace oxygen containing functional groups on surface of carbon material on cell performance of carbon anode for lithium ion batteries were studied by means of the pretreament in various oxidant/reductant systems. The results showed that the rich oxygen containing functional groups impaired the cell performance of carbon material anode, and the reduction of these groups in quantity and oxidation degree can increase charge/discharge capacity and improve first charge/discharge efficiency. The reason was also discussed in the light of effects of surface organic groups on decomposition reactivity of electrolyte and formation process of surface passivating film.

The Current Distribution On The Anode Surface Of The Seale Oval Tubular Lead Acid Battery, Renao Gu, Jianlin Yao, Zhengfa Deng, Ru Sun, Liren Wu, Zhongsi Jiang, Wangen Miao

Journal of Electrochemistry

The current distribution on anode surface of sealed lead acid batter under different discharge current and degree was studied by chemical analytical method for the first time. We can conclude that the current distribution is not even. The current density on the edge of the electrode surface and the electrode terminal are bigger than other areas, that is, there are edge effect and terminal effect, and these effect are more obvious when the discharge current is 100 A and degree is 100%.

High Active Platinum Plated Titanium Electrode, Xiufeng Xiao, Zeshan Zhu, Yanzhen Chen, Wenyun Hu

Journal of Electrochemistry

To prepare the adherent and high active platinum plated titanium electrode, ultrasonic agitation technology and the best conditions of electrodeposition were adopted. Ultrasonic agitation technology can be improved the cohesion between coatings and substrate. The activity of electrode has related to the double layer capacity of electrode, which was due to the electrode rugosity.

Progresses In The Studies On Electrochemical And Surface Properties Of Hydrogen Storage Alloy Materials, Yong Yang, Jum Li, Zugeng Lin

Journal of Electrochemistry

Recent progresses in the studies on electrochemical and surface properties of hydrogen storage alloy materials are reviewed. This paper includes three sections: 1) Thermodynamic and kinetic studies of metal hydride electrodes, 2) Effects of micro structure and alloy elements of the materials on the electrochemical properties of the electrodes and 3) Correlation between surface properties of the alloy materials and performance of the negative electrode in the nickel metal hydride batteries.

Quantitative Evaluation Of Electrochemical Properties Of Mh Alloy By Powder Microelectrode, Ronghui Hu, Hanxi Yang, Jingcheng Liu, Shengxian Li, Chuanxin Cha

Journal of Electrochemistry

In this paper, a quantitative method by use of powder microelectrode combined with cyclic voltammetry and galvanostatic step is described for studying the electrochemical performance characteristic of hydrogen storage alloy(MH). Since the powder microelectrode uses only MH powder and has its depth and diameter of several tens of micrometer, the ohmic and concentration ploarization are greatly reduced and the influences of the technical factors in electrode preparation on the material performance are simply eliminated. Thus, with accurate determination of the load quantity of MH alloy in power microelectrode by absorption spectrometric technique, it is feasible to evaluate quickly and quantitatively …

Comparison Of The Charge/Discharge Charasteristics Between Ni-Cd And Ni-Mh Battery And Its Improvement Of Manufacture Technique, Yumimg Wang, Jinsheng Chen

Journal of Electrochemistry

Based on the difference of charge discharge charasteristies between Ni-Cd and Ni-MH battery, some appropriate manufacture technoque to improve the battery performances or to extend its service life are adopted.

Wear And Friction Behavior Of Metal Impregnated Microporous Carbon Composites, Gultekin Goller, D. P. Koty, Surendra N. Tewari, M. Singh, A. Tekin

Chemical & Biomedical Engineering Faculty Publications

Metal-matrix composites have been prepared by pressure-infiltration casting of copper-base alloy melts into microporous carbon preforms. The carbon preforms contained varying proportions of amorphous carbon and graphite. Load dependence of the wear and friction behavior of the composite pins has been examined under ambient conditions against cast-iron plates, using a pin-on-plate reciprocating wear tester. The wear resistance of the composite is significantly improved, as compared with the base alloy. Contrary to the normally expected behavior, the addition of graphite to the amorphous carbon does not reduce the friction coefficient, especially at high loads. The wear and friction behavior of the …

An Esr Study Of Free Radicals In Electroreduction Process Of Allyl Alcohol, Jindong Zhang, Yafei Kuang, Shukun Huang, Naixian Xie, Fengzhen Wang, Dewen Chen

Journal of Electrochemistry

Electrochemical-ESR technique with spin trap phenyl-t-butyl nitrone(PBN)was used to study the intermediates of electroreduction of allyl alcohol at platinized platinum electrode in acidic alcohol-aqua solution. Hydrogen and allyl group and(or)propyl group radicals were identified by a hyperfine spectrum of the radical adducts, and that provided a direct evidence for the presence of these radicals in the electroreduction of allyl alcohol.

A Study On Solid Polymer Electrolyte Fuel Cell, Hongfeng Xu, Ming Han, Baolian Yi, Xinge Zhang, Shanhai Ge

Journal of Electrochemistry

Solid polymer electrolyte fuel cell (SPEFC) show promise of a high level of performance in the present fuel cell. In this paper, we report the method of SPEFC electrode preparation,and the effects of temperature, pressure and gas flow rate on the performance.

Improvement Of The Anti-Interference Characteristics Of God Electrode By Using The Powder Microelectrode Technique, Chen Jian, Chuansin Cha

Journal of Electrochemistry

The electrochemical behavior of ascorbic acid(AA), uric acid(UA), L-cystein(L-Cys) and acetaminophen (APAP), i.e. The main interference to the GOD electrode, were studied at the Pt,GC and powder microelectrode. Experimental results indicated that, due to the electrochemical activity of these interference, it is difficult to eliminate their interference effects by manipulation of electrode materials or working potential of the GOD electrode. However, it was found that the limiting curtents at the KB electrode are mainly controlled by mass transfer in liquid phase, so it is only related to the geometer size of the electrode, not its real surface area. Therefore, it …

Studies On The Charge And Discharge Reaction Of Li/Lini0.3Co0.7O2 Battery, Fupjng Zhang

Journal of Electrochemistry

The charge and discharge reaction of Li/LiNi_0.3Co_0.7O₂ battery have been studied by using CV,CT,XRD and GCP. It is shown that the discharge capacity of the cell reaches 120-140 mA·h·g^-1 in the 4.30-3.00 V in 1 mol/L LiClO₄/PC electrolyte system. The discharge mechanism involve a two-step Li⁺ intercalation reaction. The thermodynamic data such as ΔG,ΔS, ΔH, of the reaction are given. Furthermore, the changes of the D or σ_i of Li⁺ with its composition have been discussed.

The Effect Of Co On The Proton Diffusion Coefficient For The Ni(Oh)2 Electrodes, Xiaoyan Cao, Zuoxiang Zhou, Huatang Yuan, Yunshi Zhang

Journal of Electrochemistry

The diffusion coefficients of protons moving in the Ni(OH)₂ electrodes have being investigated by constant current, cyclic voltammetry and potential step technineques. The electrodes were prepared by cathodic deposition and their active material contained 0～53% cobalt. It was found that the diffusion coefficients are about 10^-9～10^-10 cm²/s during charging and about 10^-11 cm²/s during discharging. Moreover the value increases with the increacing content of Co in the electrodes. During the calculation, the relevant fomulars were modified especially the wrong fomular for constant current methode.

Electrochemical Study Of The Corrosion Behavior Of Coalesced Copper And Sw-206 Stainless Steel In The Acetic-Acid Solution, Rongzong Hu, Changjian Lin, Jianguang Tan, Zhanmei Sun, Xueqin Wu, Biao Wang

Journal of Electrochemistry

In order to provide a theoretic and experimental consideration for the material selection and anit-corrosion in the petrochemical industries the corrosion behavior of coalesced copper and sw-206 stainless steel in the acetic acid solution was studied by electrochemical impedance spectroscopy and polarization techniques. The effects of the temperature, acetic acid concentration and solubilized oxygen in the acetic acid solution on the corrosion process of this two metals were analyzed. It was found that these effects obviously accelerate corrosion process for the coalesced copper, but no apparent influnce for the sw-206 stainless steel.In the the acetic acid solution, containing water and …

Electrodeposition Of Cu-Co Multilayer Thin Films, Jiangyun Xue, Jixun Wu, Dejun Yang

Journal of Electrochemistry

A method has been developed to produce Cu-Co Multilayer from a single electrolyte by electrodeposition. The effects of the concentration of copper ions, current density and the speed of rotation were investigated, and the Cu-Co electrodeposition films were analysed by TEM, AES and X-ray diffraction. The results indicated that the film was alternating pure copper and coppercobalt alloy layers. If the content of copper in cobalt layer is to be small, the concentration of its ions in solution must be small and the rotation speed must be low.

A Study On Electrochemical Oxidation Of Reduced Nicotinamide Coenzyme Nadh In Organic Media, Fangzu Yang, Huihuang Wu, Shukai Xu, Shaomin Zhou

Journal of Electrochemistry

The behaviour of electrochemical oxidation of the reduced nicotinamide coenzyme NADH on glassy carbon was studied and some kinetic parameters were measured by means of voltammometry in the N-dimethylformamide (DMF) and 1,4-dioxane media respectively. The eletrochemical oxidation of NADH shows completely irriversable both in the two solvents,and the diagnostic experiments support that the process involves a fast chemical step.The oxidation rate and the diffusion coefficient of NADH in DMP are smaller than those in 1,4-dioxane, but the response current is more stable in DMF. The experimental results are discussed by solvent effects.

Study On The Growth Process Of Lead Dioxide On Lead-Antimony Electrodes By Impedance Tracing Method, Guolin Wei, Hongxin Yang, Jiarong Wang

Journal of Electrochemistry

The growth process of PbO₂ formed by the oxidation of PbSO₄ in the anodic film on lead-(1,3,5,7)wt% antimony electrodes was investigated with impedance tracing method of single frequency and the current-time transient method. The influence of antimony on this process was studied.The simulation curves obtained for capacity-time transients fit the experimental results very well. It has been shown that the mentioned growth process is a two-dimentional instantaneous nucleation and growth process. Antimony will inhibit the growth of PbO₂ nucleus but enhance its nucleation.

A Preliminary Study Of Electrochemically Amplified Measurement Of Gold Electrodeposition, Bingwei Mao, Caihui Shi, Xiaoqin Li, Lihua Xiong

Journal of Electrochemistry

Gold electrodeposition onto a glassy carbon microelectrode is studied using an electrochemical amplification method. Taking the advantage that the electrochemical reduction of K₂Cr₂O₇ has significantly higher reaction activity on gold electrode than carbon electrode, it is tentatively used to amplify the gold electrodeposition current. The results show that there is a marked increase in current of gold electrodeposition in presence of K₂Cr₂O₇ in comparison with that absent of K₂Cr₂O₇.The electrochemical amplification method can be applied to study the electrodeposition of very in intial stage …

Surface Raman Spectra Obtained From Various Electrodeposited Transidon Metals, Jingsong Gao, Bin Ren, Qunjian Huang, Zhongqun Tian

Journal of Electrochemistry

Good quality potential-dependent surface Raman spectra of pyridine were obtained for the first time from a series of transition metals, e. g., Fe, Co, Ni, Ru, Rh, Pd and Pt, which were electrodeposited on non-SERS-active substrates. The influences of the applied potential and the nature of metal on the adsorption behaviors were discussed briefly. This result illustrates that Raman spectroscopy is becoming a more general and powerful tool to study various electrochemical interfaces.

Effects Of Elevated Temperature On The Physical Aging Of A High Temperature Thermoplastic Resin And Composite, Mark Feldman

Mechanical & Aerospace Engineering Theses & Dissertations

Development of a High Speed Civil Transport is considered by the commercial aviation industry to be one of the next big challenges for our national aircraft industry. Critical to the success of this aircraft is the development of advanced polymeric composites for both the primary and secondary structures and the predictive methodology necessary for assessment of long term durability. While polymeric composites offer an excellent strength to weight ratio a key disadvantage is the time dependent properties exhibited by the polymer matrix which can age and ultimately effect the resultant stiffness of a laminate.

Experimental studies were performed to determine …

Electrocatalytic Reduction Of Nitrite In The Presence Of Complex Of Cobalt(Ⅱ) And 1,10 Phenanthroline, Jian Tong, Xiaojun Dang, Hulin Li

Journal of Electrochemistry

The electrochemistry of cobalt(Ⅱ)-1,10-phenanthroline Co(Phen)₂²⁺ complex and its ability to electrocatalyze the reduction of nitrite were studied, we found that this complex could act as a catalyst in alkaline or neutral solution for nitrite reduction. We have investigated the effect of the complex composition on electrocatalytic ability. The effects of pH value, complex concentration, regeneration and activation of electrocatalyst on the catalytic current have been studied and discussed.

Study On Electrode Constructure And Electrical Performance Of Na/S Cell, Jianhua Yang, Jiadi Cao

Journal of Electrochemistry

A sodium wick for sodium electrode and trough shaped performs for sulfur electrode in Na/S cell were designed and investigated. The experiments suggested that the sodium wick for sodium electrode not only improved the discharge performance of cell but also reduced the quantity of sodium utilization, and increased the specific energy of Na/S cell. The trough shaped preform with alumina fibres for sulfur electrode decreased the polarization, improved the charge acceptance and prolonged the life of cell.

Studies Of Surface Treatment Methods And Their Operating Mechanisms For Activation Of Hydrogen Storage Electrode, Ronghui Hu, Hanxi Yang, Shigang Lu, Shengxian Li, Jingcheng Liu, Chongzhi Yang

Journal of Electrochemistry

Surface treatment methods by use of charge discharge cycling, KBH₄ reduction and KOH etching were parallely investigated for the rapid activation of Mn(NiCoMnAl)₅ electrode. It is found that the MH electrode treated with hot and concentrated KOH solution exhibits rapid and full activation, and also gives lower discharge overvoltage, higher stable capacity and improved cycleability. It is also revealed from SEM, EDAX and ICP analysis that the KOH activation of the electrode proceeds mainly through the enrichment of mischmetal and nickel in surface to form electrocatalytically active surface for hydrogen absorption reaction, but the surface modification with KBH …

The Applications Of Poap Ni2+ Films Modified Electrode As Sensor For Alcohol, Bingzeng Hua, Wenyun Hu, Yanzhen Chen

Journal of Electrochemistry

POAP Ni²⁺ films modified electrode can electrocatalyzes significantly the oxidation of alcohol. The modified electrode can be used as the electrochemical sensor for the detection of alcohol. But the oxidation of alcohol is effected by the thickness of films、the concentration of nickel ion in films, pH of electrolyte, as well as temperative. All of those conditions have been studied in order to achieve stable response current during the oxidation of alcohol, and the relation between concentration and current has been made. At last the major characteristic parameters, such as the low limitation of concentration, the response time, the ability …