POSITIVE ELECTRODE ACTIVE MATERIAL CONTAINING LITHIUM COMPOSITE OXIDE AND COVERING MATERIAL AND BATTERY

A positive electrode active material includes a lithium composite oxide and a covering material that covers a surface of the lithium composite oxide. The covering material has an electron conductivity of 10S/m or less. The lithium composite oxide is a multiphase mixture including a first phase having a first crystal structure that belongs to a space group Fm-3m and a second phase having a second crystal structure that belongs to a space group other than a space group Fm-3m. The ratio I/Iof a first integrated intensity Iof a first maximum peak present at a first diffraction angle 2θ of 18° or more and 20° or less to a second integrated intensity Iof a second maximum peak present at a second diffraction angle 2θ of 43° or more and 46° or less in an XRD pattern of the lithium composite oxide satisfies 0.05≤I/I≤0.90.