TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The mixture ratio by weight of the polymer of compounds to the selected compound is 1:0.0001-0.0001:1. The mixture ratio by weight of the total of the polymer of compounds and the chosen compound is 1:0.1-1:50.Preferred Compounds: The polymer of compounds comprises polyethylene glycol di(meth)acrylate with weight average molecular weight of 170-4400000.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The polymer electrolyte further comprises 0.0001-10 wt.pts of a curing initiator, 0.01-2 wt.pts of a curing catalyst, 0.1-10 wt.pts of the lithium salt and 90-99.9 wt.pts of the organic solvent.Preferred Curing Initiator: The curing initiator is at least one chosen from 21 compounds such as dibenzoyl peroxide, succinic acid peroxide and dilauroyl peroxide.Preferred Curing Catalyst: The curing catalyst includes one or more amines chosen from triethylamine, tributylamine, triethanolamine and N-benzyldimethylamine.Preferred Solvent: The organic solvent is at least one chosen from propylene carbonate, ethylene carbonate, dimethylcarbonate, diethylcarbonate, methylethylcarbonate, diethylcarbonate, tetrahydrofuran, 2-methylhydrofuran, diethoxyethane, methylformate, gamma-butrolactone and ethylformate.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Salt: The lithium salt is chosen from lithium perchlorate (LiClO4), LiBF4, lithium hexafluoro phosphate (LiPF6), lithium trifluoromethane sulfate (LiCF3SO3) and LiN(CF3SO2)2.Preferred Method: The method for preparing lithium battery, further involves interposing a separator (2) made from an insulating resin having a network structure, between the cathode and the anode prior to forming the electrode assembly.Preferred Separator: The separator comprises one of a single-layered separator of polyethylene or polypropylene, a double-layered separator of polyethylene/polypropylene or a triple-layered separator of polyethylene/polypropylene/polyethylene or polypropylene/polyethylene/polypropylene.Preferred Condition: The method of preparing lithium battery involves thermally treating the formed lithium battery at a thermal treatment temperature of 20-85degreesC, preferably 60-80degreesC.Preferred Property: The thickness of polymer electrolyte coated on the insulative resin is 5-90 mum. Preferred Definitions:    R4 = methyl or ethyl group.    EXAMPLE - Polyethylene glycol dimethacrylate (in g) (8.18), vinyl acetate (0.91), azobisisobutyronitrile (0.01) as curing initiator, triethylamine (0.01) as curing catalyst and an electrolytic solution (90.87) (obtained by dissolving 1.3 M lithium hexafluoro phosphate (LiPF6) in a solvent of ethylene carbonate and diethyl carbonate in mixture ratio by weight of 3:7), were mixed, and a polymer electrolyte forming composition was obtained. The composition was cast on a Teflon (RTM; polytetrafluoroethylene) substrate and cured at 80degreesC for 2 hours. Subsequently, a film was stripped-off from the substrate, and a polymer electrolyte was obtained. Subsequently, a lithium secondary battery was produced using the polymer electrolyte. The polymer electrolyte was made into disc-shaped pellet, and contacted with a stainless steel electrode to measure ionic conductivity at room temperature. The polymer electrolyte had excellent ionic conductivity of 3.1x10-3 S. The lithium battery produced using the polymer electrolyte, had charging capacity of 770.6 mAh, discharging capacity of 763.9 mAh, efficiency of 99.1%, rate-dependent discharge capacity of 750.8 mAh at 0.5degreesC and 732.6 mAh at 2degreesC, and low temperature discharge capacity of 608.7 mAh at -20degreesC.