POLYMER ELECTROLYTE AND LITHIUM POLYMER BATTERY USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a polymer electrolyte with high mechanical strength and high ionic conductivity by using a polymer alloy film prepared by mixing or compatibilizing a polymer slightly soluble in an organic electrolyte and a polymer soluble in it. SOLUTION: A polymer alloy film prepared by mixing or compatibilizing a polymer slightly soluble in an organic electrolyte and a polymer soluble in it is impregnated with the organic electrolyte to obtain a gelled electrolyte 3. The gelled electrolyte 3 obtained is not fluid because the slightly soluble polymer is entangled microscopically each other to fix the soluble polymer, and has high mechanical strength and high ionic conductivity. By placing the gelled electrolyte 3 between a negative electrode layer 2 and a positive electrode layer 4, a lithium polymer battery having discharge characteristics equal to a battery having a liquid electrolyte is obtained. The polymer slightly soluble in the organic electrolyte is preferable to be polyvinylidene fluoride or a copolymer of polyvinylidene fluoride, and the polymer soluble in it is preferable to be polyethylene oxide.