Patent ID: 7700237

Claim:
Hydrogen storage alloy comprising: composition expressed by a general formula: (La a Pr b Nd c Z d ) 1-w Mg w Ni z-x-y Al x T y (where Z is at least one element selected from the group consisting of Ce, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ca, Sr, Sc, Y, Yb, Ti, Zr and Hf and Z includes Sm as an indispensable element, and T is at least one element selected from the group consisting of V, Nb, Ta, Cr, Mo, Mn, Fe, Co, Ga, Zn, Sn, In, Cu, Si, P and B, and subscripts a, b, c and d fall in ranges of 0≦a≦0.25, 0<b, 0<c, and 0.05≦d≦0.20, respectively, and satisfy the relationship expressed by a+b+c+d=1, where 0.20≦b/c≦0.35, and subscripts x, y, z and w fall in ranges of 0.15≦x≦0.30, 0≦y≦0.5, 3.3≦z≦3.8, and 0.05≦w≦0.15, respectively).