摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rare earth-Mg-Ni based hydrogen storage alloy having excellent alkali resistance in a high temperature environment, to provide a hydrogen storage alloy electrode using the alloy, and to provide a nickel-hydrogen secondary battery in which deterioration in battery properties caused by leaving in a high temperature environment is suppressed using the alloy. <P>SOLUTION: The nickel-hydrogen secondary battery comprises the particle (36) of a hydrogen storage alloy in a negative electrode (26), and this hydrogen storage alloy has a composition expressed by general formula: (La<SB>a</SB>Sm<SB>b</SB>Gd<SB>c</SB>A<SB>d</SB>)<SB>1-w</SB>Mg<SB>w</SB>Ni<SB>x</SB>Al<SB>y</SB>Ti<SB>z</SB>; wherein, A and T denote at least one kind of element selected from the group consisting of Pr, Nd or the like, and the group consisting of V, Nb or the like, respectively, subscripts a, b, c, d satisfy the relations expressed by a>0, b≥0, c>0, 0.1>d≥0, and a+b+c+d=1, respectively, and subscripts w, x, y, z lie in the ranges shown by 0.1≤w≤0.3, 0.05≤y≤0.35, 0≤z≤0.5, and 3.2≤x+y+z≤3.8, respectively. <P>COPYRIGHT: (C)2009,JPO&INPIT |