Negative active material for a rechargeable lithium battery, method for preparing the same, and rechargeable lithium battery including the same

A method for preparing negative active material for a rechargeable lithium battery, the method comprising:

• preparing a mixed powder by mixing a vanadium-containing raw powder and a lithium-containing raw powder, or by mixing a vanadium-containing raw powder, a lithium containing raw powder, and an M element-containing raw powder, where the M element includes at least one of Al, Cr, Mo, Ti, W, and Zr;
• subjecting the mixed powder to a first heat-treatment at about 500° C. to about 900° C. for about 1 to about 5 hours under a first atmosphere to obtain a lithium-vanadium-based oxide powder;
• press-forming the lithium-vanadium-based oxide powder;
• subjecting the press-formed powder to a second heat-treatment at about 900° C. to about 1400° C. for about 3 to about 10 hours under a second atmosphere that is a reducing atmosphere;
• and
• grinding the heated press-formed powder to provide a compound powder represented by Formula 1:
• LixMyVzO2+d (1),
• wherein, in Formula 1, 1≦x≦2.5, 0≦y≦0.5, 0.5≦z≦1.5, 0≦d≦0.5, and M is an element including at least one of Al, Cr, Mo, Ti, W, and Zr, and
• wherein the compound powder includes a multi-faced particle that has a plurality of flattened parts, the multi-faced particle has at least three ridgelines at a boundary between adjacent flattened parts, and at least one of the ridgelines is formed by adjacent flattened parts at an angle of at least 90°.