Positive electrode active material and preparation method therefor, positive electrode sheet, secondary battery, and electrical device

Abstract

A positive electrode active material and a preparation method therefor, a positive electrode sheet, a secondary battery, and an electric device, wherein the positive electrode active material comprises hollow secondary particles, the hollow secondary particles comprising LiaNixCoyMnzAqMpOb, 0.25≤a≤1.2, 1.8≤b≤2, 0.3≤x≤0.6, 0≤y≤0.4, 0<z≤0.4, 0≤q≤0.02, and 0<p≤0.02, the atomic percentage of element M at grain boundaries being greater than or equal to the atomic percentage of element M in bulk phase parts of primary particles, and element A being distributed in the hollow secondary particles in the form of bulk phase doping. The positive electrode active material comprises the hollow secondary particles, element M is mainly distributed at the grain boundary of the hollow secondary particles, and element A can be optionally doped, thereby keeping good cycle performance while effectively improving the power performance.

Dependencies are inferred from the claim text.