ELECTROCHEMICAL DURABILITY OF CA-BASED ALLOYS

In order to improve the cycling durability of Ca-based alloy in KOH solution as hydride electrode in Ni-H battery, we investigated the substitution effects by using Al and Co to substitute nickel as well as alkaline earth metals and rare earth elements to calcium in CaNi5. It was found that rare earth and alkaline earth substitution can significantly improve the cycling durability during electrochemical charging and discharging. Comparing with A-site substitution in AB(5), B-site substitution by Al or Co shows little improvement on the durability. The structural and metalographical analyses have been done to understand the substitution effects.