| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydrogen storage electrode material, capable of properly controlling the ratio of rare-earth elements to transition metals in a hydrogen storage alloy after sintering, and to provide a negative electrode material for a metal-hydrogen alkaline storage battery having superior electrical capacity and charging-discharging cycle characteristic. SOLUTION: The composition of an alloy power is made identical among particles before sintering by dissolving a hydrogen storage alloy to be followed by quick cooling, so as to control the ratio of rare-earth elements to transition metals after sintering. The composition of the hydrogen storage alloy is preferably expressed by the formula R(Ni)a ,(Mn)b ,(Al)c (Co)d (M)e . (where, R is La or a mixture of La and one or more of rare earth elements (a), (b), (c), (d), (e) and (x) are coefficients expressing atomic ratios and respectively satisfies 1.8<=a<=5.5, 0.0<=b<=0.6, 0.0<=c<=0.4, 0.0<=d<=1.0, 0.0<=e<=0.2, and 4.0<=a+b+c+d+ e<=5.5; M is at least one kind of element selected from among the group comprising Si, Fe, Pb, Ti, Ca, Mg, Cu, In, Zn, Mo and Zr). |
