HYDROGEN-ABSORBING ALLOY POWDER, ITS COMPACT, AND ELECTRODE FOR ALKALINE STORAGE BATTERY

摘要

PROBLEM TO BE SOLVED: To improve the corrosion resistance of a hydrogen-absorbing alloy and to improve durability with respect to long-term storage characteristics when used for a secondary battery and storage characteristics after charge/ discharge cycling. SOLUTION: Hydrogen-absorbing alloy powder capable of reversibly absorbing and desorbing hydrogen is provided, and coated hydrogen-absorbing alloy powder having rare-earth oxides and/or rare-earth hydroxides present in island shape on the surface of the hydrogen-absorbing alloy powder and also having alkali- resistant and water-insoluble polymers further applied to the above surface is also provided. Further, a hydrogen-absorbing alloy compact or electrode obtained from the above coated hydrogen-absorbing alloy powder is provided. The hydrogen-absorbing alloy compact or electrode can reversibly absorb and desorb hydrogen and can be obtained from the hydrogen-absorbing alloy powder having the rare-earth oxides and/or rare-earth hydroxides in an island shape on the surface, and further, the surface of the hydrogen-absorbing alloy compact is coated with the alkali-resistant and water-soluble polymers.