POSITIVE-ELECTRODE ACTIVE MATERIAL CONTAINING LITHIUM COMPOSITE OXIDE, AND BATTERY INCLUDING THE SAME

A positive-electrode active material contains a lithium composite oxide containing manganese. The crystal structure of the lithium composite oxide belongs to a space group Fd-3m. The integrated intensity ratio I/Iof a first peak Ion the (111) plane to a second peak Ion the (400) plane in an XRD pattern of the lithium composite oxide satisfies 0.05≤I/I≤0.90.