| abstract |
Provided are a lithium composite metal compound having a high cycle maintenance rate, a positive electrode active material for a lithium secondary battery using the lithium composite metal compound, a positive electrode for a lithium secondary battery, and a lithium secondary battery. A lithium composite metal compound represented by a composition formula (I), which is a crystal showing a diffraction peak within a range of 2θ = 18.7 ± 1 ° in powder X-ray diffraction measurement using CuKα ray. child size is defined as L a, 2 [Theta] = 64.5 when the crystallite diameter having a diffraction peak within the range of ± 1 ° is defined as L b, the L a and the L b ratio of (L a / A lithium mixed metal compound, wherein L b ) satisfies L a / L b ≦ 1.3. 【Selection chart】 None |