Graphite material was used as the electrode for an all-vanadium redox flow battery, and the electrode was modified by transition metallic ions to enhance its electrochemical behavior. An porous graphite composite elec...Graphite material was used as the electrode for an all-vanadium redox flow battery, and the electrode was modified by transition metallic ions to enhance its electrochemical behavior. An porous graphite composite electrode has high specific surface area and high current density. The electrode modified by transition metallic ions has improved catalysis behavior that can catalyze the V（Ⅱ）-V（Ⅴ） redox reaction showed by cyclic voltammograms. This article studied the impedance of the modified electrode by electrochemical impedance spectroscopy （EIS）, and approved that the electrode modified by Co^2＋ and Mn^2＋ has a lower charge transfer resistance than the non-modified electrode. The effect of average particle size distribution is at lower frequencies that the slope of Warburg impedance is reduced by large particle size distribution. The voltage efficiency of the Co^2＋ modified electrode test cell is 81.5%, which is higher than that of the non-modified electrode.展开更多
The paper presents ac impedance behaviours of phenyl iso-thiocyanate adsorbed on Pt electrode.Nyquist plots are analysed and simulated,and parameters of relative equivalent circuits are obtained.
The impedance diagram of hdrogen storage electrodes(AH electrodes )displayed twosemicircles.Thelow frequency one is affected by cycle number and composition of MH electrodes.
Oxygen reduction(OR)on Teflon-bonded carbon electrodes with manganese oxide as catalyst in 6 mol/L KOH solution was investigated using AC impedance spectroscopy combined with other techniques. For OR at this electrode...Oxygen reduction(OR)on Teflon-bonded carbon electrodes with manganese oxide as catalyst in 6 mol/L KOH solution was investigated using AC impedance spectroscopy combined with other techniques. For OR at this electrode, the Tafel slope is –0.084 V/dec and the apparent exchange current density is (1.02-3.0)×10-7 A/cm2. In the presence of manganese oxide on carbon electrode, the couple Mn3+/Mn4+ reacts with the O2 adsorbed on carbon sites forming O ?2 radicals and acceletes the dismutation of O 2?, which contributes to the catalytic effect of manganese oxide for OR reaction.展开更多
基金This work was financially supported by the National Natural Science Foundation of China (No. 90510001).
文摘Graphite material was used as the electrode for an all-vanadium redox flow battery, and the electrode was modified by transition metallic ions to enhance its electrochemical behavior. An porous graphite composite electrode has high specific surface area and high current density. The electrode modified by transition metallic ions has improved catalysis behavior that can catalyze the V（Ⅱ）-V（Ⅴ） redox reaction showed by cyclic voltammograms. This article studied the impedance of the modified electrode by electrochemical impedance spectroscopy （EIS）, and approved that the electrode modified by Co^2＋ and Mn^2＋ has a lower charge transfer resistance than the non-modified electrode. The effect of average particle size distribution is at lower frequencies that the slope of Warburg impedance is reduced by large particle size distribution. The voltage efficiency of the Co^2＋ modified electrode test cell is 81.5%, which is higher than that of the non-modified electrode.
文摘The paper presents ac impedance behaviours of phenyl iso-thiocyanate adsorbed on Pt electrode.Nyquist plots are analysed and simulated,and parameters of relative equivalent circuits are obtained.
文摘The impedance diagram of hdrogen storage electrodes(AH electrodes )displayed twosemicircles.Thelow frequency one is affected by cycle number and composition of MH electrodes.
基金Project(1766-394201123) supported by the Natural Science Foundation of Hunan Province, China
文摘Oxygen reduction(OR)on Teflon-bonded carbon electrodes with manganese oxide as catalyst in 6 mol/L KOH solution was investigated using AC impedance spectroscopy combined with other techniques. For OR at this electrode, the Tafel slope is –0.084 V/dec and the apparent exchange current density is (1.02-3.0)×10-7 A/cm2. In the presence of manganese oxide on carbon electrode, the couple Mn3+/Mn4+ reacts with the O2 adsorbed on carbon sites forming O ?2 radicals and acceletes the dismutation of O 2?, which contributes to the catalytic effect of manganese oxide for OR reaction.
