ELECTROLYTE COMPOSITION, SECONDARY CELL, AND METHOD FOR MANUFACTURING ELECTROLYTE SHEET

Provided is an electrolyte composition, comprising one or two or more polymers, oxide particles, at least one electrolyte salt selected from the group consisting of a lithium salt, a sodium salt, a calcium salt, and a magnesium salt, and a solvent, wherein structural units constituting the one or two or more polymers comprises a first structural unit selected from the group consisting of tetrafluoroethylene and vinylidene fluoride, and a second structural unit selected from the group consisting of hexafluoropropylene, acrylic acid, maleic acid, ethyl methacrylate, and methyl methacrylate, a content of the one or two or more polymers is more than 90% by mass based on a total amount of polymers in the electrolyte composition, and a mass ratio of a content of the first structural unit to a content of the second structural unit in the one or two or more polymers is 50/50 or more.