Patent ID: 8748040
Filing Date: 2014-06-10
Classification: H01M,Y02E

Abstract:
1. A negative electrode active material for a lithium secondary battery, which includes a composition comprising Si in an amount of from 30% to 65% by mass of the negative electrode active material, the negative electrode active material comprising: a two phase matrix structure comprising an Sn—Cu based alloy matrix comprising an Sn content of 50% by mass to 95% by mass of the Sn—Cu based alloy matrix; Si crystallites dispersed in the Sn—Cu based alloy matrix; and an Si—X based alloy crystallized so as to at least partially cover the Si crystallites, wherein X is at least one element selected from Fe, Ni, and Co, and is added in an amount from 3% to 15% by mass of the negative electrode active material.