Positive electrode active material, positive electrode plate, battery, management method and application

The invention provides a positive active material, a positive pole piece, a battery, a battery management method and a power utilization device. The positive electrode active material comprises a lithium-rich manganese-based material with the chemical formula of nLi2MnO3. (1-n) LiMO2 and a ternary material with the chemical formula of LiNiaMn (1-a-b) M 'bO2, and the mass percentage of the lithium-rich manganese-based material is greater than or equal to 50% based on the mass percentage of the positive electrode active material. According to the present invention, in the positive electrode active material, the lithium-rich manganese-based material and the ternary material of the corresponding chemical formula are selected for matching, and the mass percentage of the lithium-rich manganese-based material in the positive electrode active material is controlled, such that the positive electrode active material can effectively achieve the high gram capacity and the low capacity fading so as to improve the cycle performance of the battery;