POSITIVE ELECTRODE ACTIVE MATERIAL AND PREPARATION METHOD THEREFOR, POSITIVE ELECTRODE PLATE, LITHIUM ION SECONDARY BATTERY, AND BATTERY MODULE, BATTERY PACK, AND APPARATUS CONTAINING SUCH LITHIUM-ION SECONDARY BATTERY

This application discloses a positive electrode active material and a preparation method thereof, a positive electrode plate, a lithium-ion secondary battery, and a battery module, battery pack, and apparatus containing such lithium-ion secondary battery. The positive electrode active material includes bulk particles and an element M-containing oxide coating layer applied on an exterior surface of the bulk particle. The bulk particle includes a nickel-containing lithium composite oxide. Bulk phases of the bulk particles are uniformly doped with element M. A surface layer of the bulk particle is an exterior doped layer doped with element M. Element M and element M are each independently selected from one or more of Mg, Al, Ca, Ce, Ti, Zr, Zn, Y, and B, and element M includes one or more of Si, Ti, Cr, Mo, V, Ge, Se, Zr, Nb, Ru, Rh, Pd, Sb, Te, Ce, and W.