| abstract |
A gel polymer electrolyte according to the present invention comprises a polymer selected from the group consisting of vinyl acetate copolymer, poly(ethylene/vinylacetate/carbon oxide: EVACM), and poly(ethylene/vinylacetate/maleic acid anhydride: EVAMA); an inorganic filler; and a liquid electrolyte that a lithium salt is dissolved in an aprotic solvent. It is preferable that the polymer material in a gel polymer electrolyte according to the present invention is in the range of 20 to 30% by weight, the inorganic material filler is in the range of 5 to 20% by weight, and the liquid electrolyte is in the range of 60 to 80 % by weight. As a specific functional group which has a high compatibility with a liquid electrolyte in the present invention is contained in the polymer material, a lithium ion becomes to move with ease in electrolyte, and the ionic conductivity is over 0.5 mS/cm which is the demand level of a gel polymer electrolyte. Also, it provides the gel polymer electrolyte material with a high film formability, a good property of containing an electrolyte, a good adhesion, and a good mechanical strength. |