Extruded carbon fuel cell components

Patent metadata

Field	Value
Publication number	US-10651484-B2
Application number	US-201214435676-A
Country	US
Kind code	B2
Filing date	Oct 19, 2012
Priority date	Oct 19, 2012
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

Fuel cell reactant flow field plates (22, 32) are formed by extruding long sections (17, 25) of carbonaceous material, either with straight grooves (18, 28) formed by the extrusion die, or by end milling or arbor milling, and then cut to a proper size, including cuts in which the edges of the plates are at an angle with respect to the grooves. Cooler plates are formed of water-permeable material (39) in which hydrophobic material (40) is impregnated so as to define coolant channels (42-44) with inlets and outlets (47, 49). A two-layer cooler plate is formed by stamping voids in one layer (51) that define coolant flow channels (52) with inlets (54) and outlets (56) while a second layer (59) is stamped with voids (61, 62) that define coolant inlet and exit headers; juxtaposition of the layers, with or without bonding, form the cooler plate. A cooler plate (65) is made by corrugating thin metal sheet, providing coolant channels (68) for cathodes and coolant channels (73) for anodes when interposed therebetween.

First claim

The invention claimed is:

1. A method, comprising:
extruding carbonaceous elongated sheets of material;
forming straight grooves into a central portion of each of the elongated sheets of material and forming a respective planar portion without grooves extending along each side of the central portion, including forming the central portion having the straight grooves and each planar portion without grooves during the extruding;
forming fuel reactant gas flow field plates by cutting a first group of the elongated sheets of material orthogonally with respect to the grooves;
forming a plurality of oxidant reactant gas flow field plates by cutting a second group of the elongated sheets of material non-orthogonally with respect to the grooves on each side of the plurality of oxidant reactant gas flow field plates;
forming fuel cell cooler plates of porous thin sheet material having opposing planar surfaces extending between a perimeter edge of each plate, the forming including impregnating at least one planar surface of each cooler plate with a hydrophobic material to delineate channels of hydrophobic material within each plate, the channels of each plate being connected between an inlet and an exit, wherein during operation hydrophobic sidewalls of each channel convey coolant along a tortuous path from the inlet to the exit internally through each cooler plate; and
forming a fuel cell stack by disposing each of a plurality of membrane electrode assemblies adjacent first sides of one of the fuel reactant gas flow field plates and one of the oxidant reactant gas flow field plates, with one of the cooler plates adjacent a second side of the reactant gas flow field plates and a second side of the oxidant reactant flow field plates.

2. The method of claim 1 wherein forming straight grooves into the central portion and forming the respective planar portions without grooves in the extruded, elongated sheet during the extruding includes forming the straight grooves and the respective planar portions with an extrusion die.

3. The method according to claim 2 , wherein each sheet of elongated carbonaceous material of the elongated sheets of material is porous and hydrophilic.

4. The method according to claim 1 , wherein forming the plurality of oxidant reactant gas flow field plates by cutting the second group of elongated sheets of material non-orthogonally with respect to the straight grooves includes cutting the second group of elongated sheets of material at an angle that is not equal to 0 degrees and not equal to 90 degrees with respect to the straight grooves on each side of the plurality of oxidant reactant gas flow field plates such that the respective planar portions of each of the plurality of oxidant reactant gas flow field plates have a triangular shape.

5. The method according to claim 4 , wherein the cutting includes the angle being greater than 0 degrees and less than 90 degrees relative to horizontal.

6. The method according to claim 2 , further comprising:
each of the sheets of elongated carbonaceous material being impervious to water.

7. A method, comprising:
extruding a carbonaceous elongated sheet of material having straight grooves that extend from a first end to a second end of the sheet of material, the extruding including forming the straight grooves during the extruding with an extrusion die;
forming a plurality of gas flow field plates by cutting the elongated sheet of material at an angle with respect to the grooves on each side of each of the plurality of gas flow field plates that is not equal to 0 degrees and not equal to 90 degrees;
forming a fuel cell cooler plate from a sheet of material which is permeable to liquid water, the forming including:
impregnating at least one planar surface of the cooler plate with a hydrophobic material to delineate channels of hydrophobic material within the plate, the at least one planar surface of the cooler plate extending between an outermost edge of the cooler plate, the channels of the plate being connected between an inlet and an exit, wherein during operation hydrophobic sidewalls of each channel that are coextensive with the at least one planar surface convey coolant along a tortuous path from the inlet to the exit internally through the cooler plate,
wherein the impregnating includes impregnating only certain portions of the at least one surface to delineate the channels, wherein a location of the sidewalls of the channels corresponds to a location of the certain portions and only the sidewalls of the channels comprise hydrophobic material; and

forming a fuel cell stack by disposing a membrane electrode assembly with a first side of the gas flow field plate adjacent the membrane electrode assembly and a second side of the gas flow field plate adjacent the fuel cell cooler plate.

8. The method according to claim 7 , further comprising:
the hydrophobic material comprises polytetrafluoroethylene.

9. A method, comprising:
forming a plurality of reactant flow field plates, the forming including extruding a sheet of material with straight grooves in an active area of at least one side of the sheet of the material and extruding a planar non-active area without grooves extending along the active area, the extruding including forming the straight grooves and the planar non-active area during the extruding with an extrusion die;
cutting a group of the plurality of reactant flow field plates non-orthogonally with respect to the straight grooves;
providing cooler plates of thin sheet material;
impregnating at least one planar surface of each cooler plate with a hydrophobic material to delineate channels of hydrophobic material within each plate, the at least one planar surface extending between a perimeter edge of each cooler plate, the channels of each plate being connected between an inlet and an exit, wherein during operation hydrophobic sidewalls of each channel convey coolant at least from the inlet in a first direction along a first channel, through a first opening to a second channel, along the second channel in a second direction opposite the first direction, through a second opening to a third channel, and along the third channel in the first direction to the exit, sidewalls of at least one of the first, second, and third channels being coextensive with the at least one planar surface; and
forming a fuel cell stack by disposing each cooler plate between respective reactant flow field plates of a plurality of adjacent fuel cells confining the flow of coolant.

10. A device, comprising:
a fuel cell stack that includes:
fuel reactant gas flow field plates that include a carbonaceous sheet of material with straight grooves in the sheet of material with ends that are orthogonal with respect to the grooves;
a plurality of oxidant reactant gas flow field plates that include a carbonaceous sheet of material with straight grooves with ends that are non-orthogonally with respect to the grooves, each of the plurality of oxidant reactant gas flow field plates including an active area including the straight grooves and a non-active area extending along the active area without grooves; and
fuel cell cooler plates of thin sheet material having opposing planar surfaces extending between opposing plate edges, each plate impregnated in at least one planar surface with a hydrophobic material to delineate channels of hydrophobic material within each plate, the channels of each plate being fluidly connected between an inlet and an exit, wherein during operation hydrophobic sidewalls of each channel convey coolant along a tortuous path from the inlet to the exit internally through each cooler plate.

11. The device of claim 10 wherein the fuel cel

Assignees

• Audi Ag

Inventors

• Patterson Jr Timothy W
• Madden Thomas H
• Darling Robert M
• Allen Glenn M

Classifications

• H01M8/026

  characterised by grooves, e.g. their pitch or depth · CPC title

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M8/04029 Primary

  Heat exchange using liquids · CPC title

• H01M8/0228

  in the form of layered or coated products · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title