| abstract |
A lithium transition metal composite oxide for use as a positive active material capable of composing a lithium secondary battery of which the internal resistance does not increase greatly even after stored in a charged state for a long period of time, and a method for readily producing such a lithium transition metal composite oxide. The lithium transition metal composite oxide is composed of a transition metal containing at least one selected from the group consisting of Co, Ni and Mn as a main composition element. The composition of a surface layer of each particle of the lithium transition metal composite oxide is made different from that of an inside of each particle. In one example, the ratio of lithium in the composition of the surface layer of each particle is made greater than that in the average composition of each particle. With the method for producing the lithium transition metal composite oxide, specific raw materials are mixed and fired in two stages. |