FLUORINE-BASED GRAFT COPOLYMER, POLYMER ELECTROLYTE CONTAINING THE COPOLYMER AND LITHIUM SECONDARY BATTERY EMPLOYING THE ELECTROLYTE

摘要

PURPOSE: A fluorine-based graft copolymer, its preparation method, a polymer electrolyte containing the copolymer and a lithium secondary battery employing the electrolyte are provided, to improve the mechanical properties, the adhesive strength to an electrode and the ion conductivity of a polymer electrolyte. CONSTITUTION: The fluorine-based graft copolymer is a graft polyethylene glycol monomethylether trifluoroethylene chloride-vinylidene fluoride copolymer represented by the formula 1, wherein n is 1-10; m is 1-5; a is 3-25; and l is 50-337. The method comprises the steps of dissolving a trifluoroethylene chloride-vinylidene fluoride copolymer and polyethylene glycol monomethylether in an organic solvent; and adding a base or an alkali metal to the mixture to react them. The polymer electrolyte comprises 100 parts by weight of the copolymer; and 5-30 parts by weight of a lithium salt.