TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The anion of lithium salt is fluorine, chlorine, bromine, iodine, nitrate, chlorate, hexafluorophosphate or tetrafluoroborate.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The electrolyte further comprises lithium salt having a concentration of 0-1 M/l. Preferred Components: The alkoxy alkyl group-containing amide compound is N-methoxyethyl methylcarbamate; N-methoxyethyl-N-methyl methylcarbamate; N-methoxymethyl-N-methyl methylcarbamate; N,N-dimethyl methoxy ethyl carbamate; N-methyl-N-methoxyethyl methoxyethyl carbamate; N-methyl-N-methoxyethyl methoxymethyl carbamate; N-methoxyethyl caprolactam; or N-methoxyethyl oxazolidinone. The anion of the lithium salt is dicyanamide, trifluoro-di(pentafluoroethyl)phosphate, trifluoro-tris(trifluoroethyl)phosphate, trifluoro-tetra(difluoroethyl)phosphate, trifluoro-penta(fluoroethyl)phosphate, trifluoro-hexa(fluoroethyl)phosphate, trifluoromethane sulfonate, bistrifluoromethylsulfanylamide, bis-difluorosulfonylamidide, bis(trifluoromethanesulfonyl), tri(pentafluorosulfanyl)carbide, tris(trifluoromethane sulfonate) carbide, trifluoroacetate, acetate, thiocyanate or bis(perfluoroethylsulfonyl)imide. The eutectic mixture having a viscosity of not greater than 200 cP comprises alkoxy alkyl group-containing compound and lithium salt having a mole ratio of 1-8:1. The anion of the lithium salt is identical to an anion of the lithium salt included in the eutectic mixture.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The gel-type polymer electrolyte is formed by polymerizing a eutectic compound, and a precursor solution containing a monomer that forms a polymer; or by impregnating the eutectic mixture in a polymer. The monomer is a vinyl monomer from acrylonitrile, methylmethacrylate, methylacrylate, methacrylonitrile, methylstyrene, vinylester, vinyl chloride, vinylidene chloride, acrylamide, tetrafluoroethylene, vinylacetate, methylvinylketone, ethylene, styrene, p-methoxystyrene and/or p-cyanostyrene. The eutectic mixture and the monomer have a ratio of 0.5-0.95:0.05-0.5. The polymer is polymethylmethacrylate, polyvinylidene difluoride, polyvinyl chloride, polyethylene oxide and/or polyhydroxyethylmethacrylate. EXAMPLE - A mixture of N-methoxyethyl-N-methyl methylcarbamate (5.8 g) and lithium hexafluorophosphate LiPF6 (2 g) was stirred for 2 hours in the presence of nitrogen circumstance to obtain desired electrolyte (7.8 g) with a viscosity of 82 cp, conductivity of 1.2 and electrochemical window of 0.45-4.5. A mixture of lithium cobalt dioxide as a cathode active material, artificial graphite as conductive material, and polyvinylidene fluoride as binder with a weight ratio of 94:3:3 was added with N-methylpyrrolidone, applied to an aluminum foil, and dried at 130 degrees C for 2 hours to obtain cathode. A mixture of anode active material, artificial graphite as conductive material, and a binder with a weight ratio of 94:3:3 was added with N-methylpyrrolidone, applied to a copper foil and dried at 130 degrees C for 2 hours to obtain an anode. The prepared cathode and anode were cut to a size of 1 cm2, interposed between separator, and injected with the prepared electrolyte to obtain a secondary battery.