| abstract |
Provided is a lithium nickel manganese cobalt based composite oxide having a large primary particle size and high bulk density suitable for use as a positive electrode material for a lithium secondary battery. A layered lithium nickel manganese cobalt based composite oxide represented by the following composition formula (1) and having an average primary particle diameter of substantially 3 to 20 μm. Li 1 + x Ni 1-y -z-p Mn y Co z M p O 2 (1) (Wherein x is 0 ≦ x ≦ 0.20, y is 0.1 ≦ y ≦ 0.5, z is 0.1 ≦ z ≦ 0.5, and p is 0 ≦ p ≦ 0.2. And 0.2 ≦ y + z + p ≦ 0.8, where M represents a metal selected from the group consisting of Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn, and Nb. [Selection figure] None |