The present invention provides a gel-like electrolyte having excellent electrolyte solution retention ability. The resin composition contains an electrolyte composition containing a solvent and an electrolyte and a vinylidene fluoride copolymer. The vinylidene fluoride copolymer is a copolymer of vinylidene fluoride and a comonomer represented by Formula (1) below, wherein R1 and R2 are each independently a hydrogen atom or a fluorine atom, R3 is a hydrogen atom, a fluorine atom, or an alkyl group having from 1 to 5 carbons, and R4 is a basic group that is capable of forming an intermolecular hydrogen bond.