Flexible graphite/metal distribution plate for a fuel cell assembly

Patent metadata

Field	Value
Publication number	US-8940457-B2
Application number	US-97086708-A
Country	US
Kind code	B2
Filing date	Jan 8, 2008
Priority date	Jan 9, 2007
Publication date	Jan 27, 2015
Grant date	Jan 27, 2015

Abstract

Fluid distribution plate ( 1 ) for a fuel cell assembly, comprising a first plate ( 11 ) made of an electrically conductive material impermeable to all the fluids used in a fuel cell assembly, said distribution plate having a useful section (S) which is the surface over which the gases used by the electrochemical reaction are distributed, said useful section (S) being bordered all around by a peripheral section (P), said first plate having a given thickness e 1 in the peripheral section and a smaller thickness e 2 in the useful section so as to form a recess from the side facing the outer face and so as to have a flat inner surface, a flexible graphite foil ( 11 C) being applied against said first plate ( 11 ) over the entire surface of the recess, the visible face of the flexible graphite foil having a distribution channel ( 111 ) for one of the fluids, said network being formed completely in the graphite foil.

First claim

What is claimed is:

1. A fluid distribution plate for a fuel cell assembly, comprising:
a first plate made of a metal impermeable to fuel fluids used in the fuel cell assembly, the first plate including:
a useful section, and
a peripheral section that borders the useful section,
wherein the first plate has a given thickness in the peripheral section and a smaller thickness in the useful section so as to define a recess; and

a flexible graphite foil applied against the first plate over the recess,
wherein a visible face of the flexible graphite foil has a distribution channel including fluid inlet and outlet orifices, the distribution channel being formed of indentations in the flexible graphite foil and positioned within the recess, and the distribution channel being in contact with and distributing the fuel fluids used in the fuel cell assembly, and
wherein the flexible graphite foil is a single, nonporous layer of graphite that is present between the distribution channel and a surface of the useful section of the first plate to isolate the fuel fluids in the distribution channel from the first plate, with the flexible graphite foil being sufficiently flexible such that the distribution channel is formable by pressing using a stamp.

2. The fluid distribution plate according to claim 1 , further comprising an inner face and an outer face, wherein the outer face supports a multilayer electrochemical cell that includes an ion-exchange membrane, wherein the flexible graphite foil is visible from a side facing the outer face, and wherein the distribution channel distributes a first gas consumed by the electrochemical cell.

3. The fluid distribution plate according to claim 1 , wherein the first plate is made of stainless steel.

4. The fluid distribution plate according to claim 1 , wherein an outer face of the peripheral section is covered with an anti-corrosion coating.

5. The fluid distribution plate according to claim 4 , wherein the anti-corrosion coating is electrically non-conductive.

6. The fluid distribution plate according to claim 4 , wherein the anti-corrosion coating also covers an edge of the first plate.

7. The fluid distribution plate according to claim 1 ,
wherein the flexible graphite foil has an area that is smaller than an area of the recess, and
wherein a filling material, impermeable to the fuel fluids flowing through the distribution channel, separates the first plate from a perimeter of the fluid inlet and outlet orifices of the distribution channel, such that the fuel fluids flowing through and contacting the distribution channel do not contact the first plate.

8. The fluid distribution plate according to claim 7 , wherein the filling material is an electrically non-conductive adhesive interposed between the flexible graphite foil and the first plate on a surface limited to a periphery of the flexible graphite foil, including over an entire perimeter of the fluid inlet and outlet orifices.

9. The fluid distribution plate according to claim 3 , wherein a bottom surface of the recess is covered with a thin layer of copper interposed between the first plate and the flexible graphite foil.

10. The fluid distribution plate according to claim 1 , further comprising a second plate made of an electrically conductive material, wherein the second plate includes:
an outer face and an inner face, wherein the inner face of the second plate is applied against an inner face of the first plate, and
a coolant circulation channel that distributes a coolant over the inner face of the second plate,
wherein the first and second plates are joined together by a uniform layer of an electrically conductive connecting material covering the inner faces of the first and second plates, forming a bipolar plate.

11. The fluid distribution plate according to claim 1 , wherein the flexible graphite foil is applied against the first plate over an entire surface of the recess.

Assignees

• Delfino Antonio
• Olsommer David
• Buchi Felix
• Michelin & Cie
• Michelin Rech Tech

Inventors

• Delfino Antonio
• Olsommer David
• Buchi Felix

Classifications

• H01M8/021

  Alloys based on iron · CPC title

• H01M8/0206

  Metals or alloys · CPC title

• H01M8/0263

  having meandering or serpentine paths · CPC title

• H01M8/0267

  having heating or cooling means, e.g. heaters or coolant flow channels · CPC title

• Y02E60/50

  Fuel cells · CPC title