| abstract |
Provision of a positive electrode active material from which a lithium ion secondary battery having high discharge capacity and excellent cycle characteristics can be obtained, and a method for manufacturing the same. It is a positive electrode active material containing the particle|grains of lithium containing composite oxide; Li α Ni a Co b Mn c Ti d M e O 2+δ (α = 1 to 1.8, a = 0.15 to 0.5, b = 0 to 0.09, c = 0.33 to 0.8, d = 0.01 to 0.1. , e = 0 to 0.1, δ = 0 to 0.8, a + b + c + d + e = 1, M = Mg, Al, Ca, etc.), and the space group R- in the X-ray diffraction pattern A lithium-containing composite in which the ratio of the peak height of the (003) plane attributed to the crystal structure of 3 m to the peak height of the (020) plane attributed to the crystal structure of space group C2/m (H 020 /H 003 ) is 0.02 or more A positive electrode active material containing particles of an oxide and having a D 90 /D 10 of 4 or less. |