Patent ID: 6974601

Claim:
A method of preparing a positive active material for a rechargeable lithium battery, the positive active material including at least one selected from the group consisting of formulas 1 to 4 and being coated with metal oxide or composite metal oxide, comprising the steps of: preparing at least one compound selected from the group consisting of formulas 1 to 4; Li x Ni 1-y Mn y F 2 (1) Li x Ni 1-y Mn y S 2 (2) Li x Ni 1-y-z Mn y M z O 2-a F a (3) Li x Ni 1-y-z Mn y M z O 2-a S a (4) where M is selected from the group consisting of Co, Mg, Fe, Sr, Ti, B, Si, Ga, Al, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No and Lr, and 0.95≦x≦1.1, 0<y≦0.99, 0≦z≦0.5, and 0<a≦0.5; coating the compound with a metal alkoxide solution, an organic solution of metal salt or an aqueous solution of metal salt; and heat-treating the coated compound.