Microelectrochemistry study of metal-hydride battery materials: Cycling behavior of LaNi3.55Mn0.4Al0.3Co0.75 compared with LaNi5 and its mono-substituted derivatives

LaNi5 intermetallic-hydride forming compound and several metal-substituted derivatives have been compared in terms of cycling behavior observed by means of the cavity microelectrode (CME) at high scan rates (50 mV s−1). LaNi3.55Mn0.4Al0.3Co0.75 was found to have a stable behavior over 1000 cycles, whereas, the capacity of LaNi5 decreases after only 200 cycles. The performances for the mono-substituted compounds are intermediate. The rechargeability decreases according to the following order: LaNi4.6Mn0.4>LaNi4.7Al0.3>LaNi4.25Co0.75>LaNi5. This study demonstrates the capability of the CME to check numerous battery materials in a very short period of time, which allows to bring out the effect due to the corrosion of the material.