| abstract |
(57) [Problem] To provide a lithium transition metal composite oxide for a positive electrode active material, which can constitute a lithium secondary battery having a small increase in internal resistance even when stored for a long time in a charged state. The present invention also provides a method for easily producing the lithium transition metal composite oxide. SOLUTION: A lithium transition metal composite oxide containing a transition metal containing at least one of Co, Ni and Mn as a main constituent element, for example, when the proportion of lithium in the surface layer composition of the particle is the average composition of the whole particle. The composition of the particle surface layer is different from the composition of the inside of the particle so that the composition is larger than the lithium ratio. In addition, the manufacturing method is a two-stage firing method in which a specific raw material is mixed and fired in two steps. |