HYDROGEN STORAGE ALLOY FOR ALKALINE STORAGE BATTERY, ALKALI STORAGE BATTERY, AND METHOD FOR MANUFA

文件类型：PDF文档
文件大小：111K
PROBLEM TO BE SOLVED : To to provide an alkali storage battery using, as a negative electrode, a hydrogen storage alloy containing rare-earth elements, Mg, Ni and Al, wherein the deterioration of the hydrogen storage alloy due to charge/discharge is suppressed so as to improve the cycle life of the alkali storage battery. SOLUTION : The alkali storage battery has a positive electrode 1, the negative electrode 2 and an alkaline electrolytic solution. For the negative electrode, hydrogen storage alloy powder which contains at least rare-earth elements, Mg, Ni and Al and in which an intensity ratio( IA/IB) of the strongest peak intensity IA appearing within a range of 2[!theta!]=31 to 33° to the strongest peak intensity IB appearing within a range of 2[!theta!]=40 to 44° in an X-ray diffraction measurement using a Cu-Kα ray, is ≥0.1. Further, in the state where the alkali storage battery is activated, Mg concentration M1 within the range of 30 nm from the surface of the hydrogen storage alloy powder and Mg concentration M2 in the inner part of the hydrogen storage alloy where oxygen concentration becomes <10wt.% satisfy the condition of M1/M2≤0.18.