Positive electrode active material containing lithium composite oxide and covering material, and battery including positive electrode active material

A positive electrode active material comprising:

• a lithium composite oxide containing at least one element selected from the group consisting of fluorine, chlorine, nitrogen, and sulfur;
• and
• a covering material that covers a surface of the lithium composite oxide,
• wherein the covering material has an electron conductivity of 106 S/m or less,
• the lithium composite oxide has a crystal structure that belongs to space group C2/m,
• a ratio of a first integrated intensity of a first peak located at a diffraction angle 2θ in a range of 18 to 20 degrees to a second integrated intensity of a second peak located at a diffraction angle 2θ in a range of 44 to 46 degrees in an XRD pattern, obtained with CuKα radiation, of the lithium composite oxide satisfies 0.05 or more and 0.90 or less, and
• the lithium composite oxide is represented by a formula LixMeyOαQβ,
• where Me is at least one selected from the group consisting of Mn, Co, Ni, Fe, Cu, V, Nb, Mo, Ti, Cr, Zr, Zn, Na, K, Ca, Mg, Pt, Au, Ag, Ru, W, B, Si, P, and Al;
• Q is at least one selected from the group consisting of F and Cl;
• and 1.15≤x≤1.3, 0.7≤y≤0.85, 1.8≤α≤1.95, and 0.05≤β≤0.2.