| abstract |
The invention belongs to the field of lithium ion batteries, and in particular relates to a positive electrode active material and a preparation method thereof, a positive electrode and a lithium ion battery. The positive active material includes a core formed of a material containing lithium iron manganese phosphate, a first shell located on the surface of the core, and a second shell located on the surface of the first shell; the material of the first shell is carbon material, and the second shell The material is Mo 2 N, which improves the conductivity of the material and solves the problem of manganese dissolution. |