Electrochemical properties of the Zr(V0.4Ni0.6)(2.4) hydrogen storage alloy electrode

In order to improve the electrocatalytic activity, hydrogen adsorption performance and activation behaviour of the Zr(V0.4Ni0.6)(2.4) alloy electrode, the alloy powder surface was modified by HF acid solution treatment. It was found that the alloy surface was transformed from a Zr-rich layer to a Ni-rich layer after the treatment and the electrocatalytic activity, hydrogen adsorption performance and activation behaviour of the alloy electrodes were significantly improved. An electrode reaction mechanism on the alloy surface (i.e. the mechanism of nickel-catalysis, hydrogen adsorption and hydrogen-transference) has been suggested. The Ni sites on the surface are not only the electrocatalytic reaction centre but also the hydrogen adsorption centre. In addition, the impedance spectra were fitted to an equivalent circuit using a non-linear, least squares fitting program.