Electrode for a fuel cell, and a membrane-electrode assembly and fuel cell system comprising the same

• US 20070231673A1
• Filed: 09/07/2005
• Published: 10/04/2007
• Est. Priority Date: 09/08/2004
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Noh, Hyung-Gon
• Granted Patent: US 8,017,284 B2
• Time in Patent Office: Days
• US Class Current: 429/483
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H01M 4/8605 Porous electrodes
• CPC Class Codes: H01M 4/92 Metals of platinum group H01M4/94 , H01M4/9058 take precedence
• CPC Class Codes: H01M 4/926 on carbon or graphite
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

The present invention relates to an electrode for a fuel cell which includes an electrode substrate composed of nano-carbon fiber, with a catalyst layer formed on the electrode substrate. The electrode substrate has a better strength than an electrode substrate composed of a conventional carbonaceous material, and a pore size which can be controlled even though the composition for forming the catalyst layer may be coated in the form of a slurry.

Claims

1. An electrode for a fuel cell, comprising:

an electrode substrate composed of nano-carbon fiber; and

a catalyst layer formed on the electrode substrate.

2. The electrode of claim 1, wherein the nano-carbon fiber has a diameter ranging from 1 to 500 nm.

3. The electrode of claim 1, wherein the electrode substrate has a thickness in the range of 10 to 1000 μ

m, and a pore size ranging from 0.1 nm to 300 μ

M.

4. The electrode of claim 1, wherein the electrode substrate comprises cloth or felt.

5. The electrode of claim 1, wherein the catalyst is selected from the group consisting of platinum, ruthenium, osmium, platinum-ruthenium alloys, platinum-osmium alloys, platinum-palladium alloys, and platinum-M alloys where M is at least one metal selected from the group consisting of Ga, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn.

6. The electrode of claim 1, further comprising a micro-porous layer between the catalyst layer and the electrode substrate.

7. A membrane-electrode assembly for a fuel cell, comprising

a polymer electrolyte membrane and an electrode positioned on each side of the polymer electrolyte membrane, each electrode comprising an electrode substrate comprising nano-carbon fiber with a catalyst layer thereon.

8. The membrane-electrode assembly of claim 7, wherein the nano-carbon fiber has a diameter ranging from 1 to 500 nm.

9. The membrane-electrode assembly of claim 7, wherein the electrode substrate has a thickness in the range of 10 to 1000 μ

m, and a pore size ranging from 0.1 nm to 300 μ

m.

10. The membrane-electrode assembly of claim 7, wherein the electrode substrate comprises cloth or felt.

11. The membrane-electrode assembly of claim 7, wherein the catalyst is selected from the group consisting of platinum, ruthenium, osmium, platinum-ruthenium alloys, platinum-osmium alloys, platinum-palladium alloys, and platinum-M alloys where M is at least one metal selected from the group consisting of Ga, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn.

12. The membrane-electrode assembly of claim 7, further comprising a micro-porous layer between the catalyst layer and the electrode substrate.

13. A fuel cell system comprising:

an electricity generation unit comprising;

a membrane-electrode assembly which includes a polymer electrolyte membrane and an electrode positioned on each side of the polymer electrolyte membrane; and

a separator arranged on each side of the membrane-electrode assembly;

a fuel supply unit; and

an oxidant supply unit.

14. The fuel cell system of claim 13, wherein the nano-carbon fiber has a diameter ranging from 1 to 500 nm.

15. The fuel cell system of claim 13, wherein the electrode substrate has a thickness in the range of 10 to 1000 μ

m, and a pore size ranging from 0.1 nm to 300 μ

m.

16. The fuel cell system of claim 13, wherein the electrode substrate comprises cloth or felt.

17. The fuel cell system of claim 13, wherein the catalyst is selected from the group consisting of platinum, ruthenium, osmium, platinum-ruthenium alloys, platinum-osmium alloys, platinum-palladium alloys, and platinum-M alloys where M is at least one metal selected from the group consisting of Ga, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn.

18. The fuel cell system of claim 13, wherein the proton-conducting polymer is selected from the group consisting of perfluoro-based polymers, benzimidazole-based polymers, polyimide-based polymers, polyetherimide-based polymers, polyphenylene sulfide-based polymers, polysulfone-based polymers, polyethersulfone-based polymers, polyetherketone-based polymers, polyether-etherketone-based polymers, polyphenylquinoxaline-based polymers, and combinations thereof.

19. The fuel cell system of claim 13, wherein the proton-conducting polymer is selected from the group consisting of poly(perfluorosulfonic acid), poly(perfluorocarboxylic acid), co-polymers of tetrafluoroethylene and fluorovinylether containing sulfonic acid groups, defluorinated polyetherketone sulfides, aryl ketones, poly(2,2′

-(m-phenylene)-5,5′

-bibenzimidazole), poly(2,5-benzimidazole), and combinations thereof.