Membrane-electrode assembly for solid polymer electrolyte fuel cell and method for producing the same

Abstract

A membrane-electrode assembly for solid polymer electrolyte fuel cells is provided which has a solid polymer electrolyte membrane having a high concentration of protonic acid groups enabling high proton conductivity and high humid condition, along with superior dimensional stability, without the membrane-electrode assembly dissolving in hot water. The membrane-electrode assembly for solid polymer electrolyte fuel cells was formed by using a polymer electrolyte composition consisting of a polymer having a cross-linking structure, this polymer electrolyte composition being obtained from a mixed solution that includes a polymer electrolyte containing a protonic acid group, a compound containing plurality of ethylenic unsaturated groups, and a solvent.

Description

Claims

1. A membrane-electrode assembly for solid polymer electrolyte fuel cells, comprising: an anode electrode,a cathode electrode, anda solid polymer electrolyte membrane,the anode electrode and the cathode electrode being disposed on opposite sides of the solid polymer electrolyte membrane, whereinthe solid polymer electrolyte membrane includes a polymer electrolyte composition consisting of a polymer having a cross-linking structure, the solid polymer electrolyte composition being obtained from a mixed solution including a polymer electrolyte containing a protonic acid group, a compound containing a plurality of ethylenic unsaturated groups, and a solvent.

2. The membrane-electrode assembly for solid polymer electrolyte fuel cells according to claim 1, wherein the compound containing the plurality of ethylenic unsaturated groups is a polyfunctional unsaturated monomer containing a plurality of (metha)acryloyl groups or vinyl groups in its molecule.

3. The membrane-electrode assembly for solid polymer electrolyte fuel cells according to claim 1, wherein the solid polymer electrolyte containing the protonic acid group includes a sulfonated polyarylene having constitutional units expressed by the general formulas (A) and (B) shown below:

4. The membrane-electrode assembly for solid polymer electrolyte fuel cells according to claim 3, wherein the sulfonated polyarylene has an ion exchange capacity of 0.3 to 5 meq/g.

5. The membrane-electrode assembly for solid polymer electrolyte fuel cells according to claim 3, wherein the sulfonated polyarylene has a molecular weight of 10,000 to 1,000,000.

6. The membrane-electrode assembly for solid polymer electrolyte fuel cells according to claim 1, wherein the mixed solution has a viscosity of 1,000 to 20,000 mPa·s.

7. The membrane-electrode assembly for solid polymer electrolyte fuel cells according to claim 1, wherein the mixed solution further contains a polymerization initiator.

8. The membrane-electrode assembly for solid polymer electrolyte fuel cells according to claim 7, wherein the polymerization initiator generates a radical by being decomposed by way of photoirradiation.

9. The membrane-electrode assembly for solid polymer electrolyte fuel cells according to claim 7, wherein the polymerization initiator is a thermal polymerization initiator.

10. The membrane-electrode assembly for solid polymer electrolyte fuel cells according to claim 1, wherein the polymer having a cross-linking structure is obtained by initiating a cross-linking reaction in the compound containing the plurality of ethylenic unsaturated groups that constitutes the mixed solution.

11. The membrane-electrode assembly for solid polymer electrolyte fuel cells according to claim 6, wherein the polymer having a cross-linking structure is obtained by initiating a cross-linking reaction in the compound containing the plurality of ethylenic unsaturated groups that constitutes the mixed solution.

12. The membrane-electrode assembly for solid polymer electrolyte fuel cells according to claim 7, wherein the polymer having a cross-linking structure is obtained by initiating a cross-linking reaction in the compound containing the plurality of ethylenic unsaturated groups that constitutes the mixed solution.

13. The membrane-electrode assembly for solid polymer electrolyte fuel cells according to claim 8, wherein the polymer having a cross-linking structure is obtained by initiating a cross-linking reaction in the compound containing the plurality of ethylenic unsaturated groups that constitutes the mixed solution.

14. The membrane-electrode assembly for solid polymer electrolyte fuel cells according to claim 9, wherein the polymer having a cross-linking structure is obtained by initiating a cross-linking reaction in the compound containing the plurality of ethylenic unsaturated groups that constitutes the mixed solution.

15. A method for producing a membrane-electrode assembly for solid polymer electrolyte fuel cells, comprising steps of: applying the mixed solution according to claim 1 onto a substrate to form a dried coating film; andinitiating a cross-linking reaction in the compound containing a plurality of ethylenic unsaturated groups that forms the coating film.

16. A method for producing a membrane-electrode assembly for solid polymer electrolyte fuel cells, comprising steps of: applying the mixed solution according to claim 6 onto a substrate to form a dried coating film; andinitiating a cross-linking reaction in the compound containing the plurality of ethylenic unsaturated groups that forms the coating film.

17. A method for producing a membrane-electrode assembly for solid polymer electrolyte fuel cells, comprising steps of: applying the mixed solution according to claim 7 onto a substrate to form a dried coating film; andinitiating a cross-linking reaction in the compound containing the plurality of ethylenic unsaturated groups that forms the coating film.

18. A method for producing a membrane-electrode assembly for solid polymer electrolyte fuel cells, comprising steps of: applying the mixed solution according to claim 8 onto a substrate to form a dried coating film; andinitiating a cross-linking reaction in the compound containing the plurality of ethylenic unsaturated groups that forms the coating film.

19. A method for producing a membrane-electrode assembly for solid polymer electrolyte fuel cells, comprising steps of: applying the mixed solution according to claim 9 onto a substrate to form a dried coating film; andinitiating a cross-linking reaction in the compound containing the plurality of ethylenic unsaturated groups that forms the coating film.