Patent ID: 11881582
Assignee: CONTEMPORARY AMPEREX TECHNOLOGY CO., LIMITED
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 14:
15. A preparation method of a positive electrode active material, comprising the following steps:
step S1: letting a lithium salt, a phosphate compound, an A salt react in a solution;
step S2: dispersing a titanium-containing compound and a nitrogen-containing organic compound into the solution obtained in step S1 for a polymerization reaction;
step S3: adding a second titanium-containing compound, a second phosphate compound, and an M salt after the polymerization reaction in step S2 ends, and when the solution becomes a suspension, adding a second lithium salt and stirring continuously; and
step S4: completely evaporating solvent in a reaction system, grinding a resulting product, and sintering the resulting product in an inert atmosphere to obtain the positive electrode active material;
wherein the positive electrode active material comprises: a core, wherein the core is a lithium-containing phosphate; a first coating layer disposed on at least part of surface of the core, wherein the first coating layer is a carbon coating layer co-doped with titanium and nitrogen; and a second coating layer disposed on at least part of surface of the first coating layer, wherein the second coating layer comprises Li1+xMxTi2−x(PO4)3, wherein M is at least one element selected from aluminum, lanthanum, indium, zirconium, gallium, and scandium, and 0.2≤x≤0.8.