NOVELTY - Slurry of a polymer substance is coated on two surfaces of a membrane. The polymer substance is polymer of vinylidene chloride and hexafluoropropylene. An anode, a cathode and the membrane coated with the polymer substance are rolled into a battery core, and packaged into an aluminum-plastic packaging film. A non-aqueous electrolyte is poured into seal of the aluminum-plastic packaging film. The sealed battery core is maintained at 60-120 degrees C to shape the non-aqueous electrolyte and the polymer substance into gel state, and to obtain a polymer lithium ion battery.    USE - Manufacture of polymer lithium ion battery.    ADVANTAGE - The method efficiently provides polymer lithium ion battery by preventing decomposition of passive film on the surface of the cathode, inhibiting the secondary reaction between the electrolytic solution and the anode, reducing the production of the gas, effectively controlling the thickness of the battery, and preventing the deformation of the battery by expansion.    DETAILED DESCRIPTION - Slurry of a polymer substance is coated on two surfaces of a membrane, and dried. The polymer substance is polymer of vinylidene chloride and hexafluoropropylene, polymer of epoxy ethane and propylene oxide, polyacrylonitrile and polymethacrylate. An anode, a cathode and the membrane coated with the polymer substance are rolled into a battery core, and packaged into an aluminum-plastic packaging film. A non-aqueous electrolyte is poured into seal of the aluminum-plastic packaging film. The non-aqueous electrolyte contains lithium salt, film-forming additive, anti-expansion additive such as triphenyl phosphate, and solvent. The molar concentration of lithium salt in the non-aqueous electrolyte is 0.8-1.2 mol/L. The content of film-forming additive in the non-aqueous electrolyte is 0.5-4 mass% with respect to content of solvent. The content of anti-expansion additive in the non-aqueous electrolyte is 0.2-1 mass% with respect to content of solvent. The sealed battery core is maintained at 60-120 degrees C to shape the non-aqueous electrolyte and the polymer substance into gel state, and to obtain a polymer lithium ion battery. The solvent is cyclic carbonate ester and chain carbonate ester. The cyclic carbonate ester is ethylene carbonate or carbonic allyl ester. The chain carbonate ester is diethyl carbonate, methyl carbonate or methyl ethyl carbonate. The film-forming additive is vinylene carbonate and/or trimethylene sulfite.