Electrode behavior of hydrogen reduction in LiCl-KCl melt II. AC impedanceanalysis

An sc impedance method was applied to analyze the electrode behavior of hyd rogen reduction in a LiCl-KCl eutectic melt containing UH. Impedance plots of the Co and Cu electrodes were explained by using the Randles-Ershler equ ivalent circuit. Whereas the impedance plots of Fe and Ni electrodes showed an extraordinary shape due to the effect of the diffusion in the finite-le ngth region and were successfully analyzed using a modified Randles-Ershler equivalent circuit, which took into account the effect of the diffusion of hydrogen atoms in the electrode. This analysis has revealed that both the semi-infinite diffusion of molecular hydrogen in electrolyte and the finite -length diffusion of hydrogen atoms in the electrode are contributing to th e reaction at the interface of the electrode. (C) 2001 The Electrochemical Society. All rights reserved.