Patent ID: 7138211

Claim:
A solidifying material for a cell electrolyte solution, characterized in that said solidifying material comprises a film or sheet of a polymer having properties that said polymer is insoluble in said cell electrolyte solution but said polymer absorbs and solidifies said cell electrolyte solution, wherein said polymer is a block copolymer comprising, as segments A, a polymer non-compatible with said cell electrolyte solution and, as segments B, a polymer compatible with said cell electrolyte solution, and absorbs and solidifies said cell electrolyte solution; a smallest unit of said block copolymer is A-B-A; and to each of said segments B, at least one group selected from the group consisting of a carboxyl group, a hydroxyl group, a sulfonic group, an amino group and a cyclic carbonate group is bonded via a —S— bond or a —C— bond or a graft copolymer comprising, as segments A, a polymer non-compatible with said cell electrolyte solution and, as segments B, a polymer compatible with said cell electrolyte solution, and absorbs and solidifies said cell electrolyte solution; and to each of said segments B, at least one group selected from the group consisting of a carboxyl group, a hydroxyl group, a sulfonic group, an amino group and a cyclic carbonate group is bonded, and a backing reinforcing said film or sheet; and said backing is a woven fabric, a nonwoven fabric or a porous film.