SOLID POLYMER ELECTROLYTE AND CELL CONTAINING THE ELECTROLYTE

A solid polymer electrolyte made of a polymer of a liquid photopolymerizable composition is provided, which is polymerized by irradiation with light at practical light intensity and amount without using a general-purpose photopolymerization initiator contributing to an efflux from the polymer and is also liquid at normal temperature. A cell using the electrolyte is also provided. A solid polymer electrolyte is made of a solid obtained by photopolymerizing a photopolymerizable composition comprising (a) an electrolyte and (b) a polymerizable compound having a polyoxyalkylene chain, wherein the photopolymerizable composition contains a photopolymerizable maleimide compound.