Vinylidene fluoride copolymer, method for producing the same, gel electrolyte, and non-aqueous battery

A production method for a forming a gel electrolyte, comprising copolymerizing at least one type of fluorine-based monomer selected from hexafluoropropylene and chlorotrifluoroethylene, vinylidene fluoride, and a compound represented by chemical formula (1) to form a vinylidene fluoride copolymer comprising, wherein the compound represented by formula (1) is added to the fluorine-based monomer and vinylidene fluoride in divided portions or continuously during copolymerization;

• wherein, in chemical formula (1), R1, R2, and R3 are each independently a hydrogen atom, a chlorine atom, or an alkyl group having from 1 to 5 carbons;
• and X is a hydroxyl group or an atomic group having a carboxyl group and having a molecular weight of not greater than 517 with a main chain having from 1 to 19 atoms;
• and
• wherein the gel electrolyte contains the vinylidene fluoride copolymer and a non-aqueous electrolyte solution and has an ionic conductivity of at least 4.86×10−3 Scm−1 and a compressive elasticity modulus of 8.57×104 Nm−2 or greater.