Patent ID: 7582381

Claim:
An alkaline storage cell comprising: a positive electrode; an alkaline electrolyte; and a negative electrode containing a hydrogen storage alloy, the hydrogen storage alloy having a composition expressed by a general expression: Ln 1-α Mg α Ni β-γ-δ T γ Al δ (where Ln represents at least one element chosen from a group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ca, Sr, Sc, Y, Ti, Zr and Hf, T represents at least one element chosen from a group consisting of V, Nb, Ta, Cr, Mo, Mn, Fe, Co, Zn, Ga, Sn, In, Cu, Si, P and B, and subscripts α, β, γ and δ represent numerical values which satisfy 0.05<α<0.12, 3.40≦β≦3.70, 0.01≦γ≦0.15 and 0.15≦δ≦0.35); wherein the hydrogen storage alloy includes a parent phase, in the parent phase a ratio (Cmin/Cave) of a minimum concentration (Cmin) of Mg to an average concentration (Cave) of Mg being greater than or equal to 0.4, and segregation phases, an area ratio of the segregation phases in a cross section of the hydrogen storage alloy being less or equal to 30%.