MEMBRANE-ELECTRODE JUNCTION AGENT, PROTON CONDUCTING MEMBRANE HAVING JUNCTION LAYER, MEMBRANE-ELECTRODE ASSEMBLY, POLYMER ELECTROLYTE FUEL CELL, AND MANUFACTURING METHOD OF THE MEMBRANE-ELECTRODE ASSEMBLY

• US 20100047659A1
• Filed: 03/12/2008
• Published: 02/25/2010
• Est. Priority Date: 03/16/2007
• Status: Active Grant

• Current Assignee: Sekisui Chemical Company Limited (Sekisui)
• Original Assignee: Sekisui Chemical Company Limited (Sekisui)
• Inventors: Kanoh, Masashi, Nakajima, Hideyasu, Miyama, Toshihito, Konno, Yoshiharu
• Granted Patent: US 8,318,377 B2
• Time in Patent Office: Days
• US Class Current: 429/532
• CPC Class Codes: H01M 8/0258 characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant
• CPC Class Codes: H01M 8/0297 Arrangements for joining electrodes, reservoir layers, heat exchange units or bipolar separators to each other H01M8/0271 takes precedence
• CPC Class Codes: H01M 8/1004 characterised by membrane-electrode assemblies [MEA] H01M8/12 takes precedence
• CPC Class Codes: H01M 8/241 with solid or matrix-supported electrolytes
• 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

A membrane-electrode junction agent, a proton conducting membrane having a junction layer, a membrane-electrode assembly, a polymer electrolyte fuel cell, and a manufacturing method of the membrane-electrode assembly, which enhance the power generation performance, realize the high fuel barrier property, and are capable of enhancing the joint strength between the membrane and the electrodes, is provided. A membrane-electrode junction agent that joins a proton conducting membrane and electrodes arranged on both surfaces of the proton conducting membrane to each other, the membrane-electrode junction agent including: a cross-linked compound (X) having a silicon-oxygen bond; a polymer material (Y) containing an acid group; and a hydrophilic resin (Z) containing no acid group.

Claims

1. A membrane-electrode junction agent joining a proton conducting membrane and electrodes arranged on both surfaces of the proton conducting membrane, comprising:

a cross-linked compound (X) having a silicon-oxygen bond; and

a polymer material (Y) containing an acid group.

2. The membrane-electrode junction agent according to claim 1, further comprising a hydrophilic resin (Z) containing no acid group.

3. The membrane-electrode junction agent according to claim 1, wherein the polymer material (Y) is a composite of a monomer (V) containing an acid group and a monomer (W) not containing an acid group and containing silicon.

4. The membrane-electrode junction agent according to claim 1, wherein the polymer material (Y) contains:

an acid group-containing polymer obtained by polymerizing a monomer (V′

) having an acid group; and

a polymerizable unsaturated double bond.

5. The membrane-electrode junction agent according to claim 1, wherein the acid group is any of a sulfonic acid group, a carboxylic acid group and a phosphoric acid group.

6. The membrane-electrode junction agent according to claim 1, wherein the cross-linked compound (X) contains an aqueous solution of silica and/or silicate.

7. The membrane-electrode junction agent according to claim 1, wherein the cross-linked compound (X) contains:

liquid alkoxysilane; and

an aqueous solution of silica and/or silicate.

8. The membrane-electrode junction agent according to claim 2, wherein the hydrophilic resin (Z) containing no acid group is either polyvinyl alcohol or polyethylene glycol.

9. A proton conducting membrane having a junction layer comprising:

the membrane-electrode junction agent according to claim 1; and

a junction layer formed of the membrane-electrode junction agent, being provided on one surface or both surfaces of the proton conducting membrane.

10. The proton conducting membrane having the junction layer according to claim 9, wherein the cross-linked compound (X) and the polymer material (Y) are bonded to each other by a silicon-oxygen bond.

11. The proton conducting membrane having the junction layer according to claim 9, wherein the junction layer is composed of a continuum of particles, and in addition, an acid group is imparted to surfaces of the particles, and proton conduction paths is formed in gaps among the particles.

12. The proton conducting membrane having the junction layer according to claim 11, wherein an average particle diameter of the particles is 3 to 200 nm.

13. The proton conducting membrane having the junction layer according to claim 9, wherein the proton conducting membrane has a cross-linked structure.

14. The proton conducting membrane having the junction layer according to claim 9, wherein the proton conducting membrane is a proton conducting membrane comprising:

an acid group-containing structure (H); and

a silicon-oxygen bonding structure (A) containing a cross-linked structure by a silicon-oxygen bond, and the silicon-oxygen bonding structure (A) is a structure represented by a following general formula (I);

(wherein R₁ is a chain hydrocarbon group containable a substituent with a carbon number of 1 to 50 and/or a heteroatom, or is an oxygen atom, R₂, R₃, R₄, R₅, R₆ and R₇ are any of hydrogen atoms, methyl groups, ethyl groups, propyl groups, butyl groups, phenyl groups, methoxy groups, ethoxy groups, propoxy groups, butoxy groups, hydroxyl groups and O—

Si—

, and may be the same or different from one another, at least one of R₂, R₃ and R₆ is O—

Si concerned with the cross-link, and at least one of R₄, R₅ and R₇ is O—

Si concerned with the cross-link.)

15. The proton conducting membrane having the junction layer according to claim 9, wherein the proton conducting membrane is a proton conducting membrane comprising a silicon-oxygen bonding structure (A) containing a cross-linked structure by a silicon-oxygen bond and an acid group-containing structure (B) covalently bonded to a silane compound and having an acid group, being coupled to each other by a silicon-oxygen bond,

wherein the silicon-oxygen bonding structure (A) is a structure represented by a following general formula (I):

(wherein R₁ is a chain hydrocarbon group containable a substituent with a carbon number of 1 to 50 and/or a heteroatom, or is an oxygen atom, R₂, R₃, R₄, R₅, R₆ and R₇ are any of hydrogen atoms, methyl groups, ethyl groups, propyl groups, butyl groups, phenyl groups, methoxy groups, ethoxy groups, propoxy groups, butoxy groups, hydroxyl groups and O—

Si—

, and may be the same or different from one another, at least one of R₂, R₃ and R₆ is O—

Si concerned with the cross-link, and at least one of R₄, R₅ and R₇ is O—

Si concerned with the cross-link.)

16. The proton conducting membrane having the junction layer according to claim 9, wherein the proton conducting membrane is a proton conducting membrane comprising a silicon-oxygen bonding structure (A) containing a cross-linked structure by a silicon-oxygen bond and an acid group-containing structure (B) covalently bonded to a silane compound and having an acid group, being coupled to each other by a silicon-oxygen bond,

wherein the silicon-oxygen bonding structure (A) is a structure represented by a following general formula (I):

(wherein R₁ is a chain hydrocarbon group containable a substituent with a carbon number of 1 to 50 and/or a heteroatom, or is an oxygen atom, R₂, R₃, R₄, R₅, R₆ and R₇ are any of hydrogen atoms, methyl groups, ethyl groups, propyl groups, butyl groups, phenyl groups, methoxy groups, ethoxy groups, propoxy groups, butoxy groups, hydroxyl groups and O—

Si—

, and may be the same or different from one another, at least one of R₂, R₃ and R₆ is O—

Si concerned with the cross-link, and at least one of R₄, R₅ and R₇ is O—

Si concerned with the cross-link.),

wherein a structure in which a silane compound (α

) having a polymerizable unsaturated double bond and an acid group-containing compound (β

) having an acid group and a polymerizable unsaturated double bond are covalently bonded to each other is contained in the acid group-containing structure (B).

17. A membrane-electrode assembly comprising:

a fuel electrode; and

an air electrode, being arranged on both surfaces of the proton conducting membrane having the junction layer according to claim 9.

18. A polymer electrolyte fuel cell comprising the membrane-electrode assembly according to claim 17.

19. A polymer electrolyte fuel cell comprising:

a unit cell made of the membrane-electrode assembly according to claim 17; and

a pair of separators which serve as passages of fuel and air, being arranged on outsides of the unit cell,

wherein a plurality of the unit cells adjacent to one another are coupled to one another.

20. A manufacturing method of a membrane-electrode assembly, comprising:

forming a membrane having a junction layer by coating the membrane-electrode junction agent according to claim 1 on both surfaces of a proton conducting membrane, followed by drying;

softening and/or swelling the membrane having the junction layer by impregnating a polar solvent into the membrane having the junction layer; and

pasting a fuel electrode and an air electrode to the softened and/or swelled membrane having the junction layer, followed by heat pressing.