CLAD METAL BIPOLAR PLATES

• US 20070264540A1
• Filed: 04/25/2007
• Published: 11/15/2007
• Est. Priority Date: 04/26/2006
• Status: Abandoned Application

• Current Assignee: Battelle Memorial Institute
• Original Assignee: Battelle Memorial Institute
• Inventors: Xia, Guanguang, Weil, Kenneth, Kim, Jin
• Application Number:
  US11/740,137
• Publication Number:
  US 20070264540A1
• Time in Patent Office: Days
• US Class Current: 429/492
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 8/0206 Metals or alloys
• CPC Class Codes: H01M 8/021 Alloys based on iron
• CPC Class Codes: H01M 8/0213 Gas-impermeable carbon-containing materials
• 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: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A clad metal bipolar plate and method for manufacture that can be cost efficiently produced and which provides excellent functional qualities. In one preferred embodiment of the invention the transition metal cladding is selected from a group of materials that form a self passivating layer when in use in a typical PEMFC operating environment. In another embodiment of the invention the transition metal cladding is selected from different types of transition metals and is treated with boron to form a transition metal boride that acts as a passivating layer when in use in a typical PEMFC operating environment. The use of transitional metal claddings over a metal core allows for various functional combinations and assists with cost effective manufacture of PEMFCs.

Claims

1. A bipolar plate adapted for use in a PEM fuel cell comprising:

a plate body having an outer surface, said outer surface having a transition metal cladding layer connected thereto.

2. The bipolar plate of claim 1 wherein the transition metal within the transition metal cladding layer is not a noble metal.

3. The bipolar plate of claim 2 wherein said transition metal cladding layer has been at least partially converted to a transition metal boride.

4. The bipolar plate of claim 3 wherein said transition metal cladding layer has been fully converted to a transition metal boride.

5. The bipolar plate of claim 1 further comprising a metal layer connected to said plate body opposite said outer surface.

6. The bipolar plate of claim 5 wherein said metal layer comprises a material selected from the group consisting of copper, nickel, tin, zinc, bismuth and alloys thereof.

7. The bipolar plate of claim 1 wherein said plate body is a metal laminate, said metal laminate comprised of a core.

8. The bipolar plate of claim 7 wherein said core is a material selected from the group consisting of plain carbon, stainless steel, alloyed steel, aluminum, aluminum alloys and combinations thereof.

9. The bipolar plate of claim 1 wherein said transition metal within said transition metal cladding is a material selected from the group consisting of niobium, tantalum, molybdenum, tungsten, titanium, zirconium, vanadium, hafnium, tin and alloys thereof.

10. The bipolar plate of claim 1 wherein said transition metal is selected from the group consisting of nickel, iron, manganese, chromium, cobalt, and alloys thereof.

11. The bipolar plate of claim 10 wherein said transition metal is coated with a boride product.

12. The bipolar plate of claim 10 wherein said transition metal has been partially converted to a boride product.

13. The bipolar plate of claim 10 wherein said transition metal has been fully converted to a boride product.

14. The bipolar plate of claim 10 wherein said transition metal cladding layer comprises a metal selected of the group consisting of Group IVA-VIA transition metals and alloys thereof.

15. The bipolar plate of claim 1 wherein said transition metal cladding layer comprises a non-noble d-transition metal.

16. The bipolar plate of claim 15 wherein said transition metal cladding layer has been at least partially boronized.

17. The bipolar plate of claim 15 wherein said transition metal cladding layer has been at least partially nitrided.

18. The bipolar plate of claim 9 wherein said transition metal cladding layer is self passivating.

19. A method for forming a bipolar plate for use in a PEM fuel cell said method comprising the step of:

forming an external boride layer upon a piece of metal laminate, said piece of metal laminate having a preselected size and shape and a non-noble d-transition metal outer layer.

20. The method of claim 19 wherein said step of forming an external boride layer includes the step of powder packing.

21. The method of claim 20 wherein said step of forming an external boride layer includes the steps of electroplating and heating.

22. The method of claim 21 wherein said step of forming includes reactive conversion of the transition metal outer layer using a boronizing gas to form the external boride layer.