| abstract |
PROBLEM TO BE SOLVED: To provide a solid electrolyte having excellent adhesion strength to an electrode active material layer, whereby a solid electrolyte having a good electrical contact state between the solid electrolyte, a positive electrode, and a negative electrode active material layer. Provide a secondary battery. SOLUTION: This is a solid electrolyte secondary battery comprising a positive electrode, a negative electrode, and a solid electrolyte interposed therebetween, wherein the solid electrolyte comprises a matrix of a block copolymer of vinylidene fluoride and hexafluoropropylene. Contains as a polymer. The block copolymer film has mechanical toughness and high solvent retention ability. By using this as a solid electrolyte matrix polymer, adhesion strength, load characteristics, and low-temperature characteristics are significantly improved. In the above block copolymer, the composition ratio of hexafluoropropylene is from 3% by weight to Preferably, the content is 7.5% by weight. The molecular weight is preferably at least 550,000, and the weight average molecular weight Mw3 More than 100,000 and less than 550,000 copolymers may be used in combination. |