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 by having as a whole a composition in which the ratio of the total number of Ni, Al, Co, and Mn atoms to the number of Mm atoms ranges from 5.5/1 to 9/1, excluding 5.5/1, and the ratio of the number of Ni atoms to that of Mm atoms is 3.5/1 or higher, and by comprising an inner structure made up of a hydrogen absorbing alloy phase represented by the general formula: AB5 and a second phase coexisting with the hydrogen absorbing alloy 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 of Ni, Al, Co, Mn, and Cu atoms to the number of Mm atoms ranges from 5.5/1 to 7.0/1, excluding 5.5/1, and the ratio of the number of Ni atoms to that of Mm atoms is 4.0/1 or higher. These hydrogen absorbing alloys are advantageous in that they combine the property of absorbing/releasing hydrogen with conductivity.