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

An anode active material for a secondary battery according to an embodiment of the present invention includes lithium-silicon composite oxide particle. The lithium-silicon composite oxide particles include at least one of LiSiO and LiSiO and have a phase fraction ratio defined by Equation 1 of 1.0 or less. A content of particles having a diameter of less than 3 µm is 5 vol% or less based on a total volume of the lithium-silicon composite oxide particles.