Patent ID: 7572552

Claim:
A nonaqueous electrolyte secondary battery comprising: a positive electrode; a negative electrode including an alloy having a CeNiSi 2 type crystal structure; and a nonaqueous electrolyte, wherein the alloy is made of a ternary alloy system that has a composition represented by a formula LnM1 x M2 y where Ln denotes at least one kind of element selected from the elements having an atomic radius falling within a range of 1.6×10 −10 m to 2.2×10 −10 m, M1 is at least one element selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Nb, M2 is at least one element selected from the group consisting of P, Si, Ge, Sn and Sb, and x and y satisfy the conditions of 0.5≦x≦1.5 and 1.5≦y≦3.5.