TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: The radical non-reactive group is 1-20C aliphatic hydrocarbon, 5-20C aromatic hydrocarbon, 1-20C ether, 1-20C ester group, -OC(=O)R'n, -OC(=O)RmOR'n or -O(C=O)RmOC(=O)R'n, where m and n are 1-20, R is (halogenated) alkylene, (halogenated) arylene, (halogenated) alkylarylene or (halogenated) aralkylene group, and R' is (halogenated) alkyl, (halogenated) aryl, (halogenated) alkylaryl or (halogenated) aralkyl group.Preferred Composition: The polymer electrolyte forming composition further comprises 0.0001-10 wt.pts of polymerization initiator and/or 0.01-2 wt.pts of polymerization catalyst. Thirty-one polymerization initiators are claimed such as succinic peroxide, diethoxy peroxydicarbonate and azobisisobutyronitrile. The polymerization catalyst is triethylamine, tributylamine, triethanolamine or N-benzyldimethylamine. The amount of lithium salt and organic solvent in the electrolytic solution is 0.1-10 wt.pts and 90-99.9 wt.pts, respectively.    TECHNOLOGY FOCUS - POLYMERS - Preferred Polymer: (Meth)acrylic ester is -OC(=O)RnOC(=O)CH=CH2, -OC(=O)RnOC(=O)C(CH3)=CH2 or -O(C=O)RnCH=CH2, where n is 1-20 and R is same as above defined.Preferred Composition: The molar ratio of (meth)acrylic ester to radical non-reactive group is 1:0.01-1:100. The weight ratio of poly(ester) (meth)acrylate or its polymer to polyalkylene glycol di(meth)acrylate and/or polyalkylene glycol (meth)acrylate, is 1:0.0001-0.0001:1. The weight ratio of mixture of poly(ester) (meth)acrylate or its polymer and polyalkylene glycol di(meth)acrylate and/or polyalkylene glycol (meth)acrylate, to electrolytic solution is 1:0.1-1:50.Preferred Properties: The weight average molecular weight of polyalkylene glycol di(meth)acrylate is 170-4400000, and that of polyalkylene glycol (meth)acrylate is 140-4400000.Preferred Separator: A separator (4) of lithium battery is single-layered polyethylene separator, single-layered polypropylene separator, double-layered separator of polyethylene/polypropylene and triple-layered separator of polyethylene/polypropylene/polyethylene or polypropylene/polyethylene/polypropylene. SPECIFIC COMPOUNDS - The organic solvent is propylene carbonate, ethylene carbonate, dimethyl carbonate, methylethyl carbonate, diethyl carbonate, tetrahydrofuran, 2-methylhydrofuran, diethoxyethane, methylformate, ethylformate or gamma-butyrolactone. The lithium salt is lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium trifluoromethane sulfonate or lithium bistrifluoromethane sulfonylamide.