Patent ID: 11417883

Abstract:
The present application discloses positive electrode active material, preparation method thereof, positive electrode plate, lithium-ion secondary battery and battery module, pack, and apparatus. The positive electrode active material includes a nickel-containing lithium composite oxide satisfying a chemical formula Li1+a[NixCoyMnzMb]O2, in the formula, M is a doping element at transition metal site, 0.5≤x<1, 0≤y<0.3, 0≤z<0.3, −0.1≤a<0.2, 0<b<0.3, x+y+z+b=1, wherein the positive electrode active material has a layered crystal structure and belongs to space group R3m; under the condition that the positive electrode active material is in 78% delithiation state, at least part of the doping elements M have a chemical valence of +3 or more, and surface oxygen of the positive electrode active material has an average valence state of VO satisfying −2.0≤VO≤−1.5.