NEGATIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY COMPRISING CRYSTALLINE TEXTURE COMPRISING SI PHASE, SIM PHASE AND AT LEAST ONE OF X PHASE AND SIX PHASE HAVING CRYSTAL DIAMETER OF 100-500 NM, ITS PREPARATION METHOD, AND LITHIUM SECONDARY BATTERY CONTAINING THE ACTIVE MATERIAL

摘要

PURPOSE: Provided are a negative electrode active material for a lithium secondary battery which inhibits the micro-pulverization of a negative electrode active material to improve cycle characteristics, its preparation method, and a lithium secondary battery containing the active material. CONSTITUTION: The negative electrode active material comprises a crystalline texture comprising a Si phase, a SiM phase and at least one of an X phase and a SiX phase, wherein the crystal diameter of the each phase is 100-500 nm. Preferably M is an element whose melting point is higher than that of the element X. M is at least one selected from the group consisting of Ni, Co, As, B, Cr, Cu, Fe, Mg, Mn, Ti and Y; X is at least one selected from the group consisting of Ag, Cu and Au; and both M and X are not Cu simultaneously.