▎ 摘　　要

NOVELTY - Lithium ion battery composite diaphragm comprises a base film and a coating layer coated on the base film, where the coating layer comprises 5-90 pts. wt. polymer substrate, 0-97 pts. wt. anode active material, and 0.5-5 pts. wt. conductive agent, the polymer substrate is at least one of polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride, polybutyl acrylate, polyacrylonitrile, and polytetrafluoroethylene. USE - Used as lithium ion battery composite diaphragm. ADVANTAGE - The composite diaphragm can replace the inert coating with the electrode active material, and to coat the anode material coating on the diaphragm, can play the role of the traditional diaphragm ceramic layer, can increase the stability and compatibility of the interface between the diaphragm and the anode without reducing safety, can contribute energy to the battery, and has better performance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) a method for preparing lithium ion battery composite diaphragm comprising (a) mixing the polymer substrate and solvent uniformly to obtain transparent colloid, (b) adding conductive agent into the transparent colloid to obtain the second colloid, (c) adding anode active material in the second colloid, stirring and dispersing uniformly to obtain slurry, and (d) coating the slurry on the base film, and drying to obtain the lithium ion battery composite diaphragm; and (2) a lithium ion battery, comprising an anode, a cathode electrode, an electrolyte, and a diaphragm, where the anode active material used by the anode is consistent with the anode active material in the lithium ion battery composite diaphragm.