Patent ID: 7906236

Claim:
A method for preparing an anode active material for a lithium secondary battery, the method comprising: (a) a step of producing a complex composed of Si particles and an oxide surrounding the Si particles by mixing a silicon oxide and a material having a negative oxide formation enthalpy (ΔH for ), an absolute value of which is greater than an absolute value of the oxide formation enthalpy of the silicon oxide by a mechanochemical process or subjecting them to a thermochemical reaction to reduce the silicon oxide; (b) a step of mixing the complex and a carbon material; and (c) a step of surface-modifying by coating the anode active material with a low crystalline or amorphous carbon material, wherein the material having the negative oxide formation enthalpy, the absolute value of which is greater than the absolute value of the oxide formation enthalpy of the silicon oxide, comprises Al.