Method for preparing anode active material, anode active material prepared therefrom and lithium secondary battery having the same

A lithium secondary battery, comprising:

• a cathode;
• an anode;
• and
• a separator interposed between the cathode and the anode, wherein the anode comprises:
• a current collector;
• and
• an anode active material layer formed on at least one surface of the current collector and comprising an anode active material, wherein the anode active material comprising a core-shell structured (SiOx—Liy)—C composite (0<x<1.5, 0<y<4) which has a core comprising (SiOx—Liy), and a shell coated on the surface of the core and comprising a carbon material,
• wherein the core-shell structured (SiOx—Liy)—C composite comprises an unreacted oxygen-containing lithium salt in an amount of 5 wt % or less, and by-products of the reaction between an oxygen-containing lithium salt and silicon oxide in an amount of 10 wt % or less, and
• wherein the battery has a normalized capacity at the 50th cycle of greater than 85%.