Separator for fuel cell, method for preparing the same, and fuel cell stack comprising the same

• US 20060134501A1
• Filed: 11/23/2005
• Published: 06/22/2006
• Est. Priority Date: 11/25/2004
• Status: Abandoned Application

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Lee, Jong-Ki, Kweon, Ho-Jin, Suh, Jun-Won
• Application Number:
  US11/286,151
• Publication Number:
  US 20060134501A1
• Time in Patent Office: Days
• US Class Current: 429/457
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 8/0204 Non-porous and characterised by the material
• CPC Class Codes: H01M 8/0206 Metals or alloys
• CPC Class Codes: H01M 8/021 Alloys based on iron
• CPC Class Codes: H01M 8/0215 Glass; Ceramic materials
• CPC Class Codes: H01M 8/0228 in the form of layered or coated products
• CPC Class Codes: H01M 8/026 characterised by grooves, e.g. their pitch or depth
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 428/12576 Boride, carbide or nitride component
• CPC Class Codes: Y10T 428/12611 Oxide-containing component

Abstract

The metal separator for a fuel cell of the present invention includes a metal substrate having reactant flow pathways and an electro-conductive anti-corrosion coating layer. The electro-conductive anti-corrosion coating layer covers the surface of the metal substrate on which the reactant flow pathways are formed. The coating layer may include metal carbides, metal oxides, and metal borides. A metal layer for improving adherence is formed between the surface of the metal substrate on which the reactant flow pathways are formed, and the electro-conductive anti-corrosion coating layer.

Claims

1. A separator for a fuel cell comprising:

a metal substrate having a surface forming reactant flow pathways;

a metal layer on the surface of the metal substrate on which the reactant flow pathways are formed; and

an electro-conductive anti-corrosion layer on the metal layer, wherein the electro-conductive anti-corrosion coating layer comprises an anti-corrosion material selected from the group consisting of metal carbides, metal oxides, metal borides, and combinations thereof.

2. The separator of claim 1, wherein the anti-corrosion layer has an average thickness from 0.1 to 100 μ

m.

3. The separator of claim 1, wherein the metal layer has an average thickness from 10 to 10000 Å

.

4. The separator of claim 1, wherein the metal in the metal layer is selected from the group consisting of titanium, cobalt, nickel, molybdenum, chromium, alloys thereof, and combinations thereof.

5. The separator of claim 1, wherein the reactant flow pathways have a depth less than or equal to 2000 μ

m.

6. The separator of claim 1, wherein the reactant flow pathways have a depth from 400 to 1000 μ

m.

7. The separator of claim 1, wherein the reactant flow pathways have a width less than or equal to 3000 μ

m.

8. The separator of claim 1, wherein the reactant flow pathways have a width from 500 to 1500 μ

m.

9. The separator of claim 1, wherein the anti-corrosion material has electrical conductivity greater than or equal to 100 S/cm.

10. The separator of claim 1, wherein the anti-corrosion material has a corrosion value less than or equal to 16 μ

A/cm2.

11. The separator of claim 1, wherein the metal carbide is selected from the group consisting of titanium carbide (TiC), zirconium carbide (ZrC), hafnium carbide (HfC), vanadium carbide (VC), niobium carbide (NbC), tantalum carbide (TaC), tungsten carbide (WC), and combinations thereof.

12. The separator of claim 1, wherein the metal oxide is selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), and combinations thereof.

13. The separator of claim 1, wherein the metal boride is selected from the group consisting of titanium boride (TiB2), zirconium boride (ZrB2), chromium boride (CrB2), and combinations thereof.

14. The separator of claim 1, wherein the metal substrate is selected from the group consisting of aluminum, titanium, niobium, chromium, tin, molybdenum, zinc, zirconium, vanadium, hafnium, tantalum, tungsten, indium, stainless steel, alloys thereof, and combinations thereof.

24. A fuel cell stack comprising:

a membrane-electrode assembly comprising a polymer electrolyte membrane and electrodes positioned at each side of the polymer electrolyte membrane; and

separators of claim 1 positioned at each side of the membrane-electrode assembly.

15. A separator for a fuel cell comprising:

a metal substrate upon which reactant flow pathways are formed and coated with a mixture of a metal and an electro-conductive anti-corrosion material selected from the group consisting of metal carbides, metal oxides, metal borides, and combinations thereof.

16. A method for making a separator for a fuel cell comprising:

forming a metal layer on a metal substrate on which reactant flow pathways are formed; and

coating an electro-conductive anti-corrosion material selected from the group consisting of metal carbides, metal oxides, metal borides, and combinations thereof, onto the metal layer using deposition or slurry coating.

17. The method of claim 16, wherein the metal in the metal layer is formed by coating a metal selected from the group consisting of titanium, cobalt, nickel, molybdenum, chromium, alloys thereof, and combinations thereof.

18. The method of claim 16, wherein the metal carbide is selected from the group consisting of titanium carbide (TiC), zirconium carbide (ZrC), hafnium carbide (HfC), vanadium carbide (VC), niobium carbide (NbC), tantalum carbide (TaC), tungsten carbide (WC), and combinations thereof.

19. The method of claim 16, wherein the metal oxide is selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), and combinations thereof.

20. The method of claim 16, wherein the metal boride is selected from the group consisting of titanium boride (TiB2), zirconium boride (ZrB2), chromium boride (CrB2), and combinations thereof.

21. The method of claim 16, wherein the deposition comprises one selected from the group consisting of sputtering, thermal evaporation, electron beam evaporation, plasma enhanced vapor deposition (PECVD), physical vapor deposition (PVD), chemical vapor deposition (CVD), and combinations thereof.

22. The method of claim 16, wherein the metal substrate is selected from the group consisting of aluminum, titanium, niobium, chromium, tin, molybdenum, zinc, zirconium, vanadium, hafnium, tantalum, tungsten, indium, stainless steel, alloys thereof, and combinations thereof.

23. A method for making a separator for a fuel cell comprising:

mixing a metal powder and an electro-conductive anti-corrosion material selected from the group consisting of metal carbides, metal oxides, metal borides, and combinations thereof in an organic solvent, including a binder dissolved therein, to prepare a slurry; and

pouring the slurry into a mold and drying it to form a separator.