Composition for electrochemical device functional layer, functional layer for electrochemical device, and electrochemical device

A functional layer for an electrochemical device comprising:

• a polymer including an oxide structure-containing monomer unit, wherein
• the functional layer does not include electrode active materials,
• the functional layer further includes a binder,
• the binder is at least one selected from a group consisting of a fluoropolymer, an aliphatic conjugated diene/aromatic vinyl copolymer, a hydrogenated product of an aliphatic conjugated diene/aromatic vinyl copolymer, an aliphatic conjugated diene/acrylonitrile copolymer, a hydrogenated product of an aliphatic conjugated diene/acrylonitrile copolymer, and a polyvinyl alcohol polymer,
• the fluoropolymer is polyvinylidene fluoride,
• the oxide structure-containing monomer unit has a structure indicated by a formula (I), shown below,
• where, in the formula (I), R1 represents an alkylene group or a substituted alkylene group and n is a positive integer,
• the polymer further includes a monomer unit X other than the oxide structure-containing monomer unit,
• the monomer unit X includes at least one of a (meth)acrylic acid alkyl ester monomer unit and a (meth)acrylonitrile unit,
• the monomer unit X does not include a carboxy group-containing monomer unit, and
• the polymer has a number-average molecular weight of not less than 5,000 and not more than 15,000.