PEM fuel cell separator plate

• US 6,827,747 B2
• Filed: 02/11/2002
• Issued: 12/07/2004
• Est. Priority Date: 02/11/2002
• Status: Expired due to Term

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Blunk, Richard H., Mikhail, Youssef M., Lisi, Daniel J., Abd Elhamid, Mahmoud H.
• Primary Examiner(s): Ryan, Patrick
• Assistant Examiner(s): ANTHONY, JULIAN
• Application Number:
  US10/074,913
• Publication Number:
  US 20030152821A1
• Time in Patent Office: 1,030 Days
• Field of Search: 429/34, 296/232, 296/233, 428/297.4, 428/299.1, 427/115
• US Class Current: 29/623.1
• CPC Class Codes: H01M 8/0206 Metals or alloys
• CPC Class Codes: H01M 8/0213 Gas-impermeable carbon-containing materials
• CPC Class Codes: H01M 8/0221 Organic resins; Organic polymers
• CPC Class Codes: H01M 8/0226 in the form of mixtures
• CPC Class Codes: H01M 8/0228 in the form of layered or coated products
• CPC Class Codes: H01M 8/0247 characterised by the form characterised by a channel configuration H01M8/0258
• CPC Class Codes: H01M 8/0256 Vias, i.e. connectors passing through the separator material
• CPC Class Codes: H01M 8/0267 having heating or cooling means, e.g. heaters or coolant flow channels
• CPC Class Codes: H01M 8/04007 related to heat exchange
• 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 29/49108 Electric battery cell making
• CPC Class Codes: Y10T 428/24994 Fiber embedded in or on the surface of a polymeric matrix
• CPC Class Codes: Y10T 428/249945 Carbon or carbonaceous fiber
• CPC Class Codes: Y10T 83/0304 Grooving

Abstract

A composite separator plate for use in a fuel cell stack and method of manufacture is provided. The composite separator plate includes a plurality of elongated support members oriented generally parallel to each other and a polymeric body portion formed around the support members. The body portion includes a first surface with a plurality of flow channels and a second surface opposite the first surface. A plurality of electrically conductive fibers are disposed within the polymeric body portion, each fiber extending continuously from the first surface of the polymeric body portion to the second surface of the polymeric body portion in a through plane configuration.

Claims

1. A method of manufacturing a composite separator plate for a fuel cell, the method comprising:

preparing a lattice having a plurality of elongated support members with a plurality of conductive continuous fibers interdisposed there between;

encasing the lattice in a polymeric material to form a separator plate;

forming a plurality of channels in a first surface of the separator plate;

removing a portion of the first surface of the separator plate to form a first exposed surface and to sever the plurality of conductive continuous fibers into a plurality of filaments having a first end terminating at said first exposed surface;

removing a portion of a second surface of the separator plate to form a second exposed surface and to sever the plurality of filaments into a plurality of conductive elements having a second end terminating at the second exposed surface, each of the plurality of conductive elements extending continuously in a through plane direction from the first surface to the second surface.

2. The method of manufacturing a composite separator plate of claim 1 wherein said preparing a lattice includes lacing the fibers through the support members.

3. The method of manufacturing a composite separator plate of claim 1 wherein said encasing the lattice includes locating the lattice in a mold cavity and injecting the polymeric material into the mold cavity.

4. The method of manufacturing a composite separator plate of claim 3 wherein the mold cavity includes a first molding surface having a plurality of land cavities for forming a plurality of channels in the first surface.

5. The method of manufacturing a composite separator plate of claim 1 wherein said removing at least a portion of said first and second surfaces reduces the thickness of the body portion by at least 15%.

6. The method of manufacturing a composite separator plate of claim 1 wherein said removing a portion of said first and second surface is performed by a machining operation.

7. The method of manufacturing a composite separator plate of claim 6 wherein said machining operation is selected from the group of machining operations consisting of laser machining, water-jet machining, milling, fly cutting and sanding.

8. The method of manufacturing a composite separator plate of claim 1 further including applying an electrically conductive layer of material on the first exposed surface.

9. The method of manufacturing a composite separator plate of claim 1 further comprises removing the elongated support member to provide a plurality of passages through the separator plate.

10. The method of manufacturing a composite separator plate of claim 1 wherein said removing a portion of the first surface exposes a portion of the support member at said first exposed surface.

11. The method of manufacturing a composite separator plate of claim 1 further comprising forming a plurality of channels in the second surface of the separator plate.

12. The method of claim 1 wherein said removing of the first surface portion comprises removing spaced apart portions of said first surface, providing a plurality of first exposed surfaces, and the method further includes applying an electrically conductive layer of material on each of said first exposed surfaces.