Blockcopolymer solid electrolyte, ion-conductive membrane and process for producing the blockcopolymer

A copolymer having an arrangement of block chains in an order of B1, C1 , A, C2, and B2, wherein the block chains A, B1, B2, C1 and C2 are as defined herein, is provided, The copolymer is useful as a composition for a polymer solid electrolyte and for polymer solid electrolyte batteries and ion conductive membranes.