| abstract |
Consisting of particles containing crystals of a lithium metal composite oxide, the lithium metal composite oxide has a layered structure and contains at least Li and a transition metal, and the particles are based on a volume measured by laser diffraction particle size distribution measurement The relational formula (D90-D10)/D50 ≥ 0.90 holds for D10, D50, and D90 obtained from the cumulative particle size distribution of, and the crystal is within the range of 2θ = 18.7 ± 2° in X-ray diffraction measurement using CuKα rays. The positive electrode active material for an all-solid lithium ion battery wherein the ratio α/β of the crystallite size α at the peak and the crystallite size β at the peak within the range of 2θ = 44.6±2° is 1.0 or more. |