SEPARATION MEMBRANE FOR FUEL CELL, AND METHOD FOR PRODUCTION THEREOF

• US 20110244367A1
• Filed: 06/17/2009
• Published: 10/06/2011
• Est. Priority Date: 12/22/2008
• Status: Abandoned Application

• Current Assignee: Tokuyama Corporation
• Original Assignee: Tokuyama Corporation
• Inventors: Yanagi, Hiroyuki, Watahiki, Yuki, Fukuta, Kenji, Sadasue, Kazuyuki
• Application Number:
  US13/133,431
• Publication Number:
  US 20110244367A1
• Time in Patent Office: Days
• US Class Current: 429/492
• CPC Class Codes: H01M 8/1004 characterised by membrane-electrode assemblies [MEA] H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1023 having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes
• CPC Class Codes: H01M 8/1025 having only carbon and oxygen, e.g. polyethers, sulfonated polyetheretherketones [S-PEEK], sulfonated polysaccharides, sulfonated celluloses or sulfonated polyesters
• CPC Class Codes: H01M 8/1053 consisting of layers of polymers with at least one layer being ionically conductive
• CPC Class Codes: H01M 8/106 characterised by the chemical composition of the porous support
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

Disclosed is a membrane for a fuel cell, which comprises: a polymer electrolyte membrane which comprises a cross-linked anion-exchange resin having a strongly basic anion-exchange group such as a quaternary ammonium salt group, a quaternary pyridinium salt group and a quaternary imidazolium salt group; and a polymer which is attached on at least one surface of the polymer electrolyte membrane and has a weakly acidic group such as a polyacrylic acid. Also disclosed is a method for producing the membrane.

Claims

1. A membrane for fuel cell, which comprises

a polymer electrolyte membrane comprising a cross-linked anion-exchange resin having a strongly basic anion-exchange group, and

a polymer having a weakly acidic group, adhered to at least one side of the polymer electrolyte membrane.

2. The membrane for fuel cell according to claim 1, wherein

the polymer electrolyte membrane further comprises a porous membrane and the cross-linked anion-exchange resin is filled in the voids of the porous membrane.

3. The membrane for fuel cell according to claim 1, wherein the weight-average molecular weight of the polymer having a weakly acidic group is 8,000 to 1,000,000.

4. The membrane for fuel cell according to claim 1, wherein the adhesion amount of the polymer having a weakly acidic group is 0.0001 to 0.5 mg/cm².

5. The membrane for fuel cell according to claim 1, wherein the weakly acidic group of the polymer having a weakly acidic group is carboxyl group.

6. The membrane for fuel cell according to claim 1, wherein the polymer having a weakly acidic group is a polyacrylic acid.

7. The membrane for fuel cell according to claim 1, wherein the strongly basic group of the cross-linked anion-exchange resin having a strongly basic anion-exchange group is a quaternary ammonium salt group or a pyridinium salt group.

8. The membrane for fuel cell according to claim 1, wherein the polymer having a weakly acidic group is adhered to at least one side of the polymer electrolyte membrane in such a state that the adhesion amount of the polymer does not differ substantially before and after the immersion of the membrane for fuel cell in a 50 mass % aqueous alcohol solution of 30°

C.

9. The membrane for fuel cell according to claim 1, wherein the cross-linked anion-exchange resin having a strongly basic anion-exchange group is obtained by polymerizing a monomers composition which contains an at least bifunctional cross-linkable monomer in an amount of 0.5 to 40 mol % relative to the total polymerizable monomers.

10. The membrane for fuel cell according to claim 1, which is used in a direct liquid fuel cell.

11. A membrane-catalyst electrode assembly for fuel cell, which comprises

a membrane for fuel cell according to claim 1, and

a catalyst electrode layer bonded to at least one side of the membrane, comprising an anion-exchange resin having a strongly basic anion-exchange group and a catalyst substance.

12. A method for producing a membrane for fuel cell, characterized by contacting at least one side of a polymer electrolyte membrane comprising a cross-linked anion-exchange resin having a strongly basic anion-exchange group, with a solution of a polymer having a weakly acidic group, followed by drying, to adhere the polymer having a weakly acidic group to the surface of the polymer electrolyte membrane.

13. The method for producing a membrane for fuel cell according to claim 12, wherein the polymer electrolyte membrane comprises a porous membrane and the cross-linked anion-exchange resin having a strongly basic anion-exchange group, filled in the voids of the porous membrane.

14. A method for producing a membrane for fuel cell wherein a polymer having a weakly acidic group is adhered to the surface of a polymer c electrolyte membrane, which method is characterized by contacting at least one side of a polymer electrolyte membrane comprising a cross-linked anion-exchange resin having a strongly basic anion-exchange group, with a solution of a polymer having a weakly acidic group and then washing the polymer electrolyte membrane having the polymer having a weakly acidic group, adhered to the surface, using a solvent capable of dissolving the polymer having a weakly acidic group.

15. The method for producing a membrane for fuel cell according to claim 14, wherein the polymer electrolyte membrane comprises a porous membrane and a cross-linked anion-exchange resin having a strongly basic anion-exchange group, filled in the voids of the porous membrane.