abstract |
A negative electrode active material formed from a Si-containing alloy having a composition represented by Chemical Formula (1): SixSnyMzAaLib, wherein M represents one or two or more transition metal elements, A represents an inevitable impurity, and x, y, z, a, and b represent values of mass %, wherein 0<x<100, 0≤y<100, 0<z<100, 0.2≤b≤1.5, a represents the balance, and x+y+z+a+b=100, is used in an electric device. The negative electrode active material improves cycle durability of an electric device such as a lithium ion secondary battery. |