| 摘要 |
PURPOSE: A positive electrode active material for a lithium secondary battery and its preparation method are provided, to improve the charge/discharge characteristic and the cycle lifetime. CONSTITUTION: The positive electrode active material comprises an oxide which contains a surface treatment layer and is selected from LixM(1-y) M'yO2, LixCo(1-y)NiyO2, LixCo(1-y)MnyO2, and LixComNinM'yO2; and a halogen-based compound which contains a surface treatment layer and is selected from LixM(1-y)M'yO(2-z)Az, LixCo(1-y)NiyO(2-z)Az, LixCo(1-y)MnyO(2-z)Az, and LixComNinM'yO(2-z)Az, wherein M is Ni or Co; M' is at least one element selected from the group consisting of Al, Ni, Co, Cr, Fe, Mg, Sr, V, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No and Lr; A is a halogen; and 0.95<=x<=1.1, 0<=y<=0.5, 0<=z<=0.5, m+n = 1-y, 0<=m<=0.5, and 0<=n<= 0.5. The ratio of the oxide and the halogen compound is 10-90 : 10-90 by weight. |
