NOVELTY - A positive sheet, a negative sheet and a diaphragm are coiled to form a battery core. The positive sheet contains lithium cobalt oxide, lithium nickel oxide, lithium nickel cobalt manganese oxide, lithium manganese oxide and/or lithium iron phosphorus oxide. A nonaqueous electrolyte containing lithium salt, film-forming additive, polymeric monomer and an initiator is prepared. The nonaqueous electrolyte is injected into to-be-sealed aluminum plastic packaging film, and nonaqueous electrolyte gel is made at 50-90 degrees C. Thus, lithium ion polymer battery is manufactured.    USE - Manufacture of lithium ion polymer battery.    ADVANTAGE - The lithium ion polymer battery is manufactured using nonaqueous electrolyte secondary battery having improved thermal stability.    DETAILED DESCRIPTION - A positive sheet, a negative sheet and a diaphragm are coiled to form a battery core to-be-encapsulated in an aluminum plastic packaging film. The positive sheet contains lithium cobalt oxide, lithium nickel oxide, lithium nickel cobalt manganese oxide (LiNixCoyMnzO2, x is 0 or more, and y and z are less than 1), lithium manganese oxide (LiMn2O4, LiMnO2), and/or lithium iron phosphorus oxide (LiFePO4). The negative sheet contains artificial graphite and/or natural graphite. The diaphragm is a polyolefin micropore diaphragm with thickness of 9-40 mm and porosity of 25-50%. A nonaqueous electrolyte containing lithium salt, film-forming additive, polymeric monomer and an initiator is prepared. The lithium salt is chosen from lithium hexafluorophosphate, lithium tetrafluoroborate, Lithium bis(oxalato)borate, and/or lithium complex (LiN(CF3SO2)2 or LiN(C2F5SO2)2). The concentration of lithium salt is 0.4-1.2 mol/L. The film-forming additive is chosen from vinylene carbonate, sulfurous acid acrylic ester and their mixture. The amount of additive is 0.5-4 wt.%. The polymeric monomer contains polyoxyethylene with two functional groups, polyoxyethylene with three functional groups, propylene oxide oligomer monomer, polymeric monomer with methacrylate functional group or polymeric monomer with acrylate functional group. The amount of polymeric monomer is 0.01-8 wt.%. The monomer initiator contains poly(benzoyl peroxide) or azodiisobutyronitrile. The amount of initiator is 0.01-2 wt.%. The nonaqueous electrolyte consists of primary solvent chosen from cyclic carbamate and chain carbamate, and an electrolytic solvent. The cyclic carbamate comprises ethylene carbonate and propylene carbonate. The chain carbamate comprises diethyl carbonate, dimethyl carbonate and ethyl methyl carbonate. The nonaqueous electrolyte is injected into to-be-sealed aluminum plastic packaging film, and nonaqueous electrolyte gel is made at 50-90 degrees C. Thus, lithium ion polymer battery is manufactured.