TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The lithium salt is selected from lithium perchlorate, lithium hexafluoro-phosphate, lithium tetrafluoro-borate, lithium bis(oxalate)-borate, lithium manganate, lithium iron phosphate, lithium nickelate, and/or lithium cobalt oxide. The protective gas is nitrogen gas, helium gas, neon gas, argon gas, krypton gas or xenon gas. The initiator is a thermo-initiator selected from chloride gas, bromine gas, organic peroxide, and azo initiator.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The molecular weight of the first monomer or the molecular weight of the second monomer is 200-600. The plasticizer is a multi-arm macromolecular material. The multi-arm macromolecular material is a four-arm macromolecule material or a six-arm macromolecule material. The initiator is a photo-initiator selected from the group consisting of 1-hydroxy-cyclohexyl phenyl ketone, 2-methyl-1-(4-(methylthio)-phenyl)-2-morpholino-propiopheno, and dimethylol propionic acid. The photo-initiator is dimethylol propionic acid. The second monomer is methoxy polyethylene glycol (350) monoacrylate.    TECHNOLOGY FOCUS - POLYMERS - Preferred Method: After the providing the first monomer, the second monomer, the initiator and the lithium salt; providing a plasticizer; and mixing the plasticizer with the first monomer, the second monomer, the initiator and the lithium salt to form the mixture. The method of providing the plasticizer involves dropping a phloroglucionl-acetonitrile solution into phosphorus oxychloride to form a primary mixture; stirring the primary mixture to obtain an intermediate solution; dissolving methyl polyethylene glycol-400 into an acetonitrile to form a secondary mixture; adding the secondary mixture into the intermediate solution; and removing evaporated solution after about 48 hours, to obtain six-arm macromolecule material. The polymerizing the first monomer with the second monomer to form the interpenetrating polymer network involves putting the mixture into a protective gas, and using a UV light to irradiate the mixture for 30 minutes to 2 hours to polymerize the first monomer with the second monomer under the photo-initiator. The polymerizing the first monomer with the second monomer to form the interpenetrating polymer network involves putting the mixture into a protective gas; and heating the mixture at 40-80 degrees C for a period 0.5-24 hours, to polymerize the first monomer with the second monomer under the thermo-initiator, and transform the lithium salt into the solid solution. The mixing the first monomer, the second monomer, the initiator and the lithium salt to form the mixture involves mixing polyethyleneglycol (200) dimethacrylate with methoxy polyethylene glycol (350) monoacrylate with a predetermined ratio to form a middle mixture, and then adding lithium perchlorate and dimethylol propionic acid into the middle mixture. Preferred Components: The first monomer is polyethyleneglycol (200) dimethacrylate. EXAMPLE - The solid polymer electrolyte prepared by mixing polyethylene glycol (200) dimethacrylate with polyethylene glycol (350) monoacrylate (PEG350mA) according to polyethyleneglycol (200) dimethacrylate was less than or equal to 50 wt.% of polyethylene glycol (350) monoacrylate to form a first mixture, and then adding dimethylol propionic acid (0.1 wt.% of PEG350mA) and lithium perchlorate ( less than or equal to 10 wt.% of PEG350mA) into the first mixture to form a mixture. Then the mixture putting onto a plate in nitrogen gas; and using a UV light with a wavelength of 365 nanometers irradiate the mixture for 60 minutes to form the interpenetrating polymer network, and drying to form the solid polymer electrolyte.