TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The polymer electrolyte contains polyalkylene glycol alkyl ether alkyl (meth)acrylic acid, lithium salt, initiator and hardener. Preferred Crosslinking Agent: The crosslinking agent present in the solid polymer electrolyte is tris(2 acryloyl oxyethyl) isocyanurate, tris (2 methacryloyl oxyethyl) 1,3,5 benzene tri carboxylate and tris (2 methacryloyl oxyethyl) 1,3,5 cyclohexane tri carboxylate.Preferred Group: The polyalkylene glycol alkyl ether alkyl (meth) acrylic acid contains at least one group selected from polyethyleneglycol methyl ether methacrylic acid, polyethyleneglycol methyl ether acrylic acid, polypropylene glycol methyl ether acrylic acid, polyethyleneglycol phenyl ether acrylic acid, polyethyleneglycol dimethyl ether, polyethyleneglycol diethyl ether, polyethyleneglycol dipropyl ether, polyethyleneglycol dibutyl ether, polyethyleneglycol diglycidyl ether, polypropylene glycol dimethyl ether and polypropylene glycol diglycidyl ether.Preferred Additive: The solid polymer electrolyte contains polypropylene glycol-polyethylene glycol copolymer of dibutyl ether terminal and polyethyleneglycol polypropyleneglycol. The electrolyte contains Michler's ketone and azo isobutyronitrile compound. Preferred Salt: The lithium salt present in the solid electrolyte is lithium chlorate (LiClO4), lithium borofluoride (LiBF4), lithium phosphohexafluoride (LiPF6), lithium arsenic hexafluoride (LiAsF6), LiCF3SO3 or Li(CF3SO2)2N.Preferred Initiator: The initiator is ethyl benzoin ether, isopropyl benzoin ether, alpha methyl benzoin ethyl ether, benzoin phenyl ether, alpha acyl oxime ester, alpha, alpha diethoxy acetophenone, 1,1 dichloro acetophenone, 2 hydroxy 2 methyl 1 phenyl-1-propanone, 1 hydroxy cyclohexyl phenyl ketone, Darocur 1116, Irgacure 907, anthraquinone, diethyl anthraquinone, 2 chloro anthraquinone, chloro thioxanthone, isopropyl thioxanthone, chloro thioxanthone, benzophenone, p chloro benzophenone, benzyl benzoate, benzoyl benzoate.Preferred Method: The setting of solid polymer electrolyte composition is performed by irradiating with ultraviolet rays, electron beam, gamma rays or with heat carrier.Preferred Amount: The amount of crosslinking agent is 0.1-60 mass% of total composition. The amount of polyalkylene glycol alkyl ether alkyl (meth)acrylic acid is 0.1-85 mass%. The amount of lithium salt is 3-30 mass%. The amount of initiator is 0.5-5 mass%.