MANUFACTURE OF HYDROGEN OCCLUSION ALLOY POWDER, AND HYDROGEN OCCLUSION ALLOY ELECTRODE

摘要

PROBLEM TO BE SOLVED: To provide alloy powder suitable for a storage battery excellent in cycle life and high discharge characteristic by adding and mixing a rare earth oxide and/or a rare earth hydroxide in hydrogen occlusion powder, and achieving the heat treatment by specifying the atmosphere and the temperature. SOLUTION: A lump hydrogen occlusion alloy is heat treated in an inert atmosphere or in vacuum at the temperature of 800-1100 deg.C, and then, cooled and pulverized. A rare earth oxide and/or a rare earth hydroxide is added to the pulverized hydrogen occlusion alloy powder, mixed in a wet or dry system, and then, heat treated in the inert atmosphere or in vacuum at the temperature of 100-800 deg.C. The hydrogen occlusion alloy powder before adding the rare earth oxide and/or the rare earth hydroxide has the composition expressed by the formula (R)a (Ni)w-x-y-z (Mn)x (Al)y (Co)z , wherein R is single La or a mixture of La and at least one rare earth element, and 0.95<=a<=1.05, 4.0<=w<=6.0, 0