Abstract: Provided are a positive electrode active material and a preparation method thereof, a positive electrode plate, a secondary battery, a battery module, a battery pack, and an electric apparatus. The positive electrode active material includes a core and a shell layer enveloping the core, the core having a chemical formula LiaAxMn1-yByP1-zCzO4-nDn, where A includes one or more elements selected from Zn, Al, Na, K, Mg, Nb, Mo, and W, B includes one or more elements selected from Ti, V, Zr, Fe, Ni, Mg, Co, Ga, Sn, Sb, Nb, and Ge, C includes one or more elements selected from B, S, Si, and N, and D includes one or more elements selected from S, F, Cl, and Br; and the shell layer is a doped carbon layer, a doping element in the doped carbon layer including any one or more selected from nitrogen, phosphorus, sulfur, boron, and fluorine.

Abstract: Provided are a positive electrode active material, a method for the preparation thereof and a positive electrode plate, a secondary battery and an electrical device. The positive electrode active material having a core-shell structure, including a core and a shell cladding the core, the core has a chemical formula of LimAxMn1-yByP1-zCzO4-nDn, the shell includes a first cladding layer cladding the core, a second cladding layer cladding the first cladding layer and a third cladding layer cladding the second cladding layer, the first cladding layer includes crystalline pyrophosphates LiaMP2O7 and/or Mb(P2O7)c, the second cladding layer includes crystalline phosphate XPO4, and the third cladding layer is carbon. The positive electrode active material of the present application enables the secondary battery and electrical device to have a relatively high energy density, and good cycling performance, rate performance and safety performance.

Abstract: The present application provides a positive electrode active material, a method for the preparation thereof and a positive electrode plate, a secondary battery and an electrical device containing the same. The positive electrode active material having a core-shell structure, comprising a core and a shell covering the core, wherein the core has a chemical formula of LiaAxMn1-yByP1-zCzO4-nDn, the shell comprises a first cladding layer covering the core, and a second cladding layer covering the first cladding layer, wherein the first cladding layer comprises pyrophosphate MP2O7 and phosphate XPO4, and the second cladding layer comprises carbon. The positive electrode active material of the present application enables the secondary battery and electrical device to have a relatively high energy density, and good cycling performance, rate performance and safety performance.