Lithium ion battery positive pole piece, preparation method of positive pole piece and lithium ion battery

The invention discloses a lithium ion battery positive pole piece which comprises a current collector and a positive pole film, wherein the positive pole film consists of a positive pole active material, a conductive agent and an adhesive; and an organic high polymer substance layer is sprayed on the surface layer of the film and mainly consists of at least one of polyimide, polyvinylidene fluoride, polytetrafluoroethylene and polyacrylonitrile. The method for preparing the positive pole piece comprises the following steps: mixing the positive pole active material, the conductive agent and the adhesive, and adding the mixture into an organic solvent, thereby obtaining positive pole slurry; coating the positive pole slurry on the current collector, drying, thereby obtaining the positive pole piece; placing the positive pole piece on a heating plate in a fuming cupboard, spraying a soluble organic high polymer substance solution on the surface layer of the positive pole piece to form a soluble organic high polymer substance layer, drying, thereby obtaining the lithium ion battery positive pole piece. The positive pole piece can be assembled with a negative pole, a diaphragm and electrolyte to form the lithium ion battery disclosed by the invention. A high-voltage lithium ion battery environment can be met, and the cycle performance and rate capability of the lithium ion battery can be improved.