POSITIVE ELECTRODE ACTIVE MATERIAL AND BATTERY COMPRISING THE SAME

A positive electrode active material according to the present disclosure includes a lithium composite oxide that is a multiphase mixture including a first phase having a crystal structure belonging to a monoclinic crystal (e.g., space group C2/m), a second phase having a crystal structure belonging to a hexagonal crystal (e.g., space group R-3m), and a third phase having a crystal structure belonging to a cubic crystal (e.g., space group Fm-3m or space group Fd-3m). In addition, a battery according to an aspect of the present disclosure includes a positive electrode containing the positive electrode active material, a negative electrode, and an electrolyte. The positive electrode active material according to the present disclosure improves the capacity of the battery.