Electrochemical investigations of ZrCrmFenCopVo (m+n+o+p=2) electrode for Ni–MH battery applications

An electrochemical investigation has been made on the charge/discharge characteristics, kinetics and cycle life of ZrCrmFenCopVo (m+n+o+p=2) alloy in order to evaluate their suitability as an electrode in Ni–MH batteries. It was observed that the charging capacity was around 500 mA h/g, which corresponds to a hydrogen concentration of 3.74 hydrogen atoms/formula unit, and 20 activation cycles were required to attain the maximum capacity. The electrochemical kinetics of the charge transfer process were determined by ac impedance methods and it was found that the kinetics are controlled by both the charge transfer as well as the diffusion mechanism. The diffusion coefficient of hydrogen in the lattice has been evaluated by electrochemical methods.