Membrane and electrode structure

• US 5,330,860 A
• Filed: 04/26/1993
• Issued: 07/19/1994
• Est. Priority Date: 04/26/1993
• Status: Expired due to Term

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Banerjee, Shoibal, Grot, Walther G.
• Primary Examiner(s): KALAFUT, STEPHEN J
• Application Number:
  US08/051,822
• Time in Patent Office: 449 Days
• Field of Search: 429/33, 429/42, 106/20 B, 252/514, 502/172, 502/173
• US Class Current: 429/494
• CPC Class Codes: C25B 9/23 comprising ion-exchange membranes in or on which electrode material is embedded
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 4/86 Inert electrodes with catalytic activity, e.g. for fuel cells
• CPC Class Codes: H01M 4/8814 Temporary supports, e.g. decal
• CPC Class Codes: H01M 4/8835 Screen printing
• CPC Class Codes: H01M 4/8882 Heat treatment, e.g. drying, baking
• CPC Class Codes: H01M 8/1004 characterised by membrane-electrode assemblies [MEA] H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1009 with one of the reactants being liquid, solid or liquid-charged H01M8/12 takes precedence
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

The electrode layer of a ion exchange membrane is formed by printing a ink of catalytically active particles on the surface of the membrane. The inventive electrode ink comprises:

(a) catalytically active particles;

(b) a hydrocarbon having at least one ether, epoxy or ketone linkage and an alcohol group, preferably 1-methoxy 2-propanol; and

(c) optionally a binder, preferably perfluorinated sulfonyl fluoride polymer or perfluorinated sulfonic acid polymer.

Claims

1. An electrode composition comprising:

(a) catalytically active particles;

(b) a hydrocarbon selected from the group of 1-methoxy-2propanol, 1-ethoxy-2-propanol;

1-methoxy-2-methyl-2-propanol;

1-isopropoxy-2-propanol;

1-propoxy-2-propanol;

2-phenoxy-1-propanol;

2-ethoxy-1-propanol;

2,3-ethoxy-1-propanol;

2-methoxy- 1-propanol;

1-butoxy-2-propanol;

or mixtures thereof; and

(c) a binder.

2. The composition of claim 1 in which the hydrocarbon is nonsolid at the processing temperatures of the electrode composition.

3. The composition of claim 1 wherein the binder is a perfluorinated sulfonyl fluoride polymer.

4. The composition of claim 3 in which the polymer is hydrolyzed.

5. The composition of claim 3 in which the polymer is unhydrolyzed.

6. The composition of claim 3 in which the polymer is in a solution, suspension or dispersion of alcohol and water.

7. The composition of claim 1 in which the catalytically active particle comprises a platinum group metal.

8. The composition of claim 1 in which the catalytically active particle is on a carbon support.

9. The composition of claim 1 in which the catalytically active particles are present at about 5-40 weight percent.

10. The composition of claim 1 in which the hydrocarbon is present at about 50-95 weight percent.

11. A fuel cell comprising a membrane and electrode structure wherein the electrode comprises:

(a) catalytically active particles; and

(b) a hydrocarbon having one or more ether or ketone

linkages and an alcohol group.

12. A membrane and electrode structure comprising:

(a) an ion exchange membrane having an electrode composition applied thereto, said electrode composition comprising;

(i) catalytically active particles;

(ii) a hydrocarbon having one or more ether or ketone linkages and one or more alcohol groups; and

(iii) a binder.

13. The composition of claim 12 in which the hydrocarbon is nonsolid at the processing temperatures of the structure.

14. The composition of claim 12 in which the hydrocarbon is selected from the group of 1-methoxy-2-propanol, 1-ethoxy-2-propanol;

1-methoxy-2-methyl-2-propanol;

1-isopropxy-2-propanol;

1-propoxy-2-propanol;

2-phenoxy-1-propanol;

2-ethoxy-1-propanol;

2,3-ethoxy-1-propanol;

2-methoxy-1-propanol;

1-butoxy-2-propanol;

or mixtures thereof.

15. The composition of claim 12 in which the binder is a perfluorinated sulfonyl fluoride polymer.

16. The composition of claim 15 in which the polymer is hydrolyzed.

17. The composition of claim 15 in which the polymer is unhydrolyzed.

18. The composition of claim 15 in which the polymer is in a solution, suspension or dispersion of alcohol and water.

19. The composition of claim 12 in which the catalytically active particle comprises a platinum group metal.

20. The composition of claim 12 in which the catalytically active particle is on a carbon support.

21. The composition of claim 12 in which the catalytically active particles are present at about 5-40 weight percent.

22. The composition of claim 12 in which the hydrocarbon is present in the electrode composition at about 50-95 weight percent.