Patent ID: 9166220
Filing Date: 2015-10-20
Classification: H01M,Y02E,Y02P

Abstract:
1. A negative active material for a rechargeable lithium battery, comprising a plurality of silicon oxide particles, each silicon oxide particle having a Si phase and an O phase, wherein: each silicon oxide particle comprises an atomic percentage of the Si phase that decreases in a concentration gradient from a larger atomic percentage of the Si phase at a surface of the silicon oxide particle to a smaller atomic percentage of the Si phase towards a center of the particle; each silicon oxide particle comprises an atomic percentage of the O phase that increases in a concentration gradient from a smaller atomic percentage of the O phase at a surface of the silicon oxide particle to a larger atomic percentage of the O phase towards the center of the silicon oxide particle; and a distance between the surface of the silicon oxide particle and a depth at which the atomic percentage of the Si phase is 55 atomic % is about 2% to about 20% of a particle diameter of the silicon oxide particle.