Patent ID: 7445871

Claim:
A process of preparing a positive active material for a lithium secondary battery, comprising the steps of: adding a metal source to a doping element-containing coating liquid including a doping element-containing compound to form a surface-treated metal source having a surface-treatment layer including the doping element-containing compound on a surface of the metal source, wherein the metal source is selected from the group consisting of cobalt, manganese, nickel, and a combination thereof, and the metal source and the doping element are not the same, the doping element being at least one selected from the group consisting of Mg, Al, K, Na, Ca, Si, Fe, Cu, Zn, Ti, Sn, V, Ge, Ga, B, P, Se, Bi, As, Zr, Cr, Sr, Sc, Y, a rare earth element, and a combination thereof; preheat-treating the surface-treated metal source to prepare a positive active material precursor formed of a solid solution of the doping element and the metal source; mixing the positive active material precursor with a lithium source; and heat-treating the mixture to produce the positive active material.