Interpenetrating polymer network structured nanometer SiO2 composite electrolyte and preparation method therefor

The invention relates to a lithium ion battery composite polymer electrolyte and a preparation method therefor. The composite polymer electrolyte comprises a high-molecular polymer matrix, modified nanometer inorganic stuffing, a lithium salt and an organic solvent; the polymer matrix comprises methyl methacrylate, phenylethylene and a cross-linking agent in a copolymerization manner; and inorganic particles are organic lithium salt modified nano-silicon dioxide. A porous form composite polymer electrolyte film is prepared by methods of in situ polymerization, phase inversion and the like; and the composite polymer electrolyte film is excellent in the electrolyte adsorption capacity, high in conductivity, stable in electrochemical window, good in mechanical performance and good for processing and shaping.