HYDROGEN ABSORBING ALLOYS, PROCESSES FOR PRODUCING HYDROGEN ABSORBING ALLOYS, HYDROGEN ABSORBING ALLOY ELECTRODE, PROCESS FOR PRODUCING HYDROGEN ABSORBING ALLOY ELECTRODE, AND BATTERY

摘要

A hydrogen absorbing alloy represented by Mm-(Ni-Al-Co-Mn), characterized byhaving as a whole a composition in which the ratio of the total number of Ni,Al, Co, andMn atoms to the number of Mm atoms ranges from 5.5/1 to 9/1, excluding 5.5/1,and theratio of the number of Ni atoms to that of Mm atoms is 3.5/1 of higher, and bycomprising an inner structure made up of a hydrogen absorbing alloy phaserepresentedby the general formula: AB5 and a second phase coexisting with the hydrogenabsorbingalloy phase; and a hydrogen absorbing alloy represented by Mm-(Ni-Al-Co-Mn-Cu),which has as a whole a composition in which the ratio of the total number ofNi, Al, Co,Mn, and Cu atoms to the number of Mm atoms ranges from 5.5/1 to 7.0/1,excluding5.5/1, and the ratio of the number of Ni atoms to that of Mm atoms is 4.0/1 orhigher.These hydrogen absorbing alloys are advantageous in that they combine theproperty ofabsorbing/releasing hydrogen with conductivity.