Hydrogen storage alloy and nickel-metal hydride storage battery using the same

摘要

A hydrogen storage alloy for negative electrodes in an alkaline storage battery is disclosed. The alloy is represented by the general formula MmNixMy, wherein Mm is a misch metal or a mixture of rare earth elements, and M is at least one element selected from the group consisting of Al, Mn, Co, Cu, Fe, Cr, Zr, Ti and V and wherein 5.0>/=x +y>/=5.5, and has a microstructure comprising a phase composed of a crystal structure of CaCu5 type and is capable of absorbing and desorbing hydrogen in a reversible manner, and at least one phase consisting mainly of an element or elements other than Mm, and incapable of storing hydrogen.