Studies on hydride-forming alloys as the active material of a metal hydride electrode for a nickel metal hydride cell

Abstract

Multi-component AB/sub 5/ hydrides are attractive replacements for the cadmium electrode in nickel-cadmium batteries. The archetype compound of the AB/sub 5/ alloy class is LaNi/sub 5/, but in a typical battery electrode mischmetal is substituted for La and Ni is substituted in part by variety of metals. This paper deals with the effect on cycle life upon the partial substitution of various lanthanides for La and Sn, In, Al, Co, and Mn for Ni. The presence of Ce was shown to enhance cycle life as did Sn in some cases. An electrode of La/sub 0.67/Ce/sub 0.33/B/sub 5/ alloy gave over 3500 cycles (to specific capacity of 200 mAh/g), indicating that it is a very attractive alloy for a practical Ni/MH/sub x/ cell.