ANODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY AND LITHIUM SECONDARY BATTERY COMPRISING THE SAME

摘要

PURPOSE: An anode active material for a lithium secondary battery is provided to ensure high capacity compared with a carbon-based anode active material, little volume expansion after charging/discharging, and excellent cycleability. CONSTITUTION: An anode active material for a lithium secondary battery comprises silicon or silicon alloy capable of alloying with lithium. The volume of an inactive phase which does not react with lithium within the active material is 50-75 % based on the total volume of the active material. A method for preparing the anode active material comprises the steps of: (i) melting silicon, or silicon and alloy element in an inert atmosphere; (ii) quenching and solidifying the molten solution to prepare powder; and (iii) pulverizing the powder to prepare the anode active material powder with a predetermined average particle diameter.