简介 |
PROBLEM TO BE SOLVED : To provide a positive electrode active material which can be used even under a high charging voltage and is superior in battery performances, such as discharge capacity, discharge average voltage, charge-and-discharge cycle durability and safety.
SOLUTION : A surface-modified lithium-containing complex oxide for a lithium ion secondary battery positive electrode, comprises a lithium-containing complex oxide expressed by the following general formula (1), of which the surface is modified by a surface-modification compound including at least one element selected from the group consisting of elements in the following groups S1 and S2 (where the group S1 consists of Al, Zr, Ti, Mg, Zn, Nb, Mo, Ta, W and rare earth elements, and the group S2 consists of F, P and S) : Li1+x(Co(1-a-b-m)NiaAlbMm)1-xO2-(f/2)Ff (1) (where M represents at least one element selected from a group consisting of transition metals, Sn, Ge, Na, K, B, C, Si, P, S, Zn, Ga, and Bi, other than Co and Ni, elements of Group II and rare earth elements; -0.05≤x≤0.05; 0
|