Solid electrolyte, method for producing solid electrolyte, membrane and electrode assembly, and fuel cell

• US 20060178500A1
• Filed: 02/07/2006
• Published: 08/10/2006
• Est. Priority Date: 02/07/2005
• Status: Abandoned Application

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Kikuchi, Wataru
• Application Number:
  US11/348,232
• Publication Number:
  US 20060178500A1
• Time in Patent Office: Days
• US Class Current: 528/425
• CPC Class Codes: C08J 2325/16 Homopolymers or copolymers of alkyl-substituted styrenes
• CPC Class Codes: C08J 2327/06 Homopolymers or copolymers of vinyl chloride
• CPC Class Codes: C08J 5/2231 based on macromolecular compounds obtained by reactions involving unsaturated carbon-to-carbon bonds
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 8/04197 Preventing means for fuel crossover
• CPC Class Codes: H01M 8/1011 Direct alcohol fuel cells [DAFC], e.g. direct methanol fuel cells [DMFC]
• 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 8/103 having nitrogen, e.g. sulfonated polybenzimidazoles [S-PBI], polybenzimidazoles with phosphoric acid, sulfonated polyamides [S-PA] or sulfonated polyphosphazenes [S-PPh]
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A solid electrolyte comprising a domain including an acid moiety and a matrix domain, wherein the domain and the matrix domain form 3-dimensional crosslinking structure comprising a carbon-carbon bond of a polymer main chain and polyether crosslink, and the solid electrolyte has ion conductivity of 0.010 S/cm or more, methanol diffusion coefficient of 4×10⁻⁷ cm²/s of less, tensile strength of 40 MPa or more, and pressure strength of 500 kgf/cm² or more.

Claims

1. A solid electrolyte comprising a domain including an acid moiety and a matrix domain, wherein the domain and the matrix domain form 3-dimensional crosslinking structure comprising a carbon-carbon bond of a polymer main chain and polyether crosslink, and the solid electrolyte has ion conductivity of 0.010 S/cm or more, methanol diffusion coefficient of 4×

10<sup>−

7</sup> cm²/s of less, tensile strength of 40 MPa or more, and pressure strength of 500 kgf/cm² or more.

2. The solid electrolyte according to claim 1, comprising a repeating unit represented by the formula (1-1) below and a repeating unit represented by the formula (1-2) below:

3. The solid electrolyte according to claim 2 wherein L¹¹ in the formula (1-1) is a group comprising a mesogen.

4. The solid electrolyte according to claim 3 wherein L¹¹ in the formula (1-1) is represented by the formula (5) below:

Formula (5)

5. The solid electrolyte according to claim 4 wherein E in the formula (5) is a divalent linking group of a 6-membered aromatic group, a 4-6 membered saturated or unsaturated aliphatic group, a 5- or 6-membered heterocyclic group, or a condensed ring thereof.

6. The solid electrolyte according to claim 4 wherein E in the formula (5) is represented by any one of the following formulae:

7. The solid electrolyte according to claim 2 wherein A¹¹ in the formula (1-1) is an acid moiety having a pKa of 5 or less.

8. The solid electrolyte according to claim 2 wherein A¹¹ in the formula (1-1) is a sulfonic acid moiety, a phosphonic acid moiety or a carboxylic acid moiety.

9. The solid electrolyte according to claim 1 in a membrane form.

10. The solid electrolyte according to claim 1 comprising an optically-anisotropic domain.

19. A membrane and electrode assembly comprising a pair of electrodes and the solid electrolyte according to claim 1 arranged between the electrodes.

20. A fuel cell comprising the membrane and electrode assembly according to claim 19.

11. A method for producing a solid electrolyte comprising a domain including an acid moiety and a matrix domain, wherein the domain and the matrix domain form 3-dimensional crosslinking structure comprising a carbon-carbon bond of a polymer main chain and crosslinked polyether, the solid electrolyte has ion conductivity of 0.010 S/cm or more, methanol diffusion coefficient of 4×

10<sup>−

7</sup> cm²/s of less, tensile strength of 40 MPa or more, and pressure strength of 500 kgf/cm² or more, and the method comprises forming a polyether by crosslinking reaction.

12. The method for producing a solid electrolyte according to claim 11, comprising forming a carbon-carbon bond by polymerization reaction and then forming the polyether by crosslinking reaction.

13. The method for producing a solid electrolyte according to claim 11, comprising forming a carbon-carbon bond by polymerization reaction, coating the reaction product and then forming the polyether by crosslinking reaction.

14. The method for producing a solid electrolyte according to claim 11, comprising forming a carbon-carbon bond by polymerization reaction, coating and drying the reaction product and then forming the polyether by crosslinking reaction.

15. The method for producing a solid electrolyte according to claim 11, comprising polymerizing a compound represented by the formula (2) below and a compound represented by the formula (3) below:

16. The method for producing a solid electrolyte according to claim 11, comprising crosslinking a polymerizable compound including a repeating unit represented by the formula (4-1) below and a repeating unit represented by the formula (4-2) below:

17. The method for producing a solid electrolyte according to claim 16, wherein the polymerizable compound has a weight-average molecular weight of 3000 or more.

18. The method for producing a solid electrolyte according to claim 16, wherein the polymerizable compound has a weight-average molecular weight of 15,000 to 80,000.