The effect of over-stoichiometry on the electrochemical properties of LaNi5 derived electrode materials

Expensive cobalt has been totally replaced in over-stoichiometric LaNi5-type electrode materials by Al, Cr, Cu and Ni. In order to yield single phase materials, rapid quenching has been used when necessary. Complete characterization of the intermetallic compounds has been undertaken and hydrogenation characteristics as well as electrochemical capacity and cycling properties have been measured. The results have been analyzed in comparison with previous work in which complete replacement by Fe and Mn had been studied and shown that the cycle life is excellent for almost any compound provided over-stoichiometry is conserved.