NEGATIVE ACTIVE MATERIAL FOR RECHARGEABLE LITHIUM BATTERY, METHOD OF PREPARING SAME, AND RECHARGEABLE LITHIUM BATTERY INCLUDING SAME

摘要

PURPOSE: A negative electrode active material is provided to have excellent capacity performance, to have excellent volume change because of low volume change even upon charging/discharging, and to able to reduce irreversible capacity. CONSTITUTION: A negative electrode active material for a lithium secondary battery comprises a lithium silicide having a crystalline structure of I41-a. A manufacturing method of the negative electrode active material comprises a step of forming a mixture by mixing and milling lithium and silicon, a step of compaction of the mixture, and a step of heat treating the compacted mixture at high temperature and high pressure. 100 parts by mole or more of the lithium is mixed into the silicon. [Reference numerals] (AA) Capacity(mAh/g); (BB) Cycle number; (CC) Coulomb efficiency(%); (DD) Charging; (EE) Discharging; (FF) Coulomb efficiency(%)