NEGATIVE ACTIVE MATERIAL FOR RECHARGEABLE LITHIUM BATTERY AND RECHARGEABLE LITHIUM BATTERY INCLUDING SAME

摘要

Negative active materials for rechargeable lithium batteries are provided. One negative active material includes at least one Si active particle and a metal matrix surrounding the Si active particle. The metal matrix does not react with the Si active particle. The negative active material has a martensite phase when X-ray diffraction intensity is measured using a CuKalpha ray. The negative active material has improved efficiency and cycle-life.