Fuel cell electrolyte management device

Patent metadata

Field	Value
Publication number	US-2017170497-A1
Application number	US-201514969253-A
Country	US
Kind code	A1
Filing date	Dec 15, 2015
Priority date	Dec 15, 2015
Publication date	Jun 15, 2017
Grant date	—

Abstract

An illustrative example fuel cell electrolyte management device includes a first component having a first density and a second component having a second density that is less than the first density. The first component has a first side including a pocket and a second side facing opposite the first side. The second side of the first component includes a first plurality of fluid flow channels. The second component has a porosity configured for storing electrolyte in the second component. The second component fits within the pocket. The second component has a first side received directly against the first side of the first component. The second component has a second side including a second plurality of fluid flow channels.

First claim

We claim:

1 . A fuel cell electrolyte management device, comprising:
a first component having a first density, the first component having a first side including a pocket and a second side facing opposite the first side, the second side including a first plurality of fluid flow channels; and a second component having a second density that is lower than the first density, the second component having a porosity configured for storing electrolyte in the second component, the second component fitting within the pocket, the second component having a first side received directly against the first side of the first component, the second component having a second side including a second plurality of fluid flow channels.

2 . The device of claim 1 , wherein
the first component comprises a first type of graphite and a first type of resin; and the second component comprises a second type of graphite that is different from the first type of graphite and a second type of resin that is different from the first type or resin.

3 . The device of claim 2 , wherein
the first type of graphite comprises at least graphite flakes; and the second type of graphite comprises at least non-flake graphite.

4 . The device of claim 2 , wherein
the first resin comprises a fluoropolymer resin; and the second resin comprises a thermosetting polymeric resin.

5 . The device of claim 4 , wherein the fluoropolymer resin is between 10% and 50% by weight of the first component.

6 . The device of claim 1 , wherein the second component is at least temporarily bonded to the pocket by an adhesive that decomposes at a temperature above an ambient or room temperature.

7 . The device of claim 1 , wherein the second component is at least temporarily bonded to the pocket by an adhesive that is situated along a border of the pocket.

8 . The device of claim 6 , wherein the first density is at least 2 gm/cm 3 .

9 . The device of claim 1 , wherein the first density is effective as a barrier to prevent electrolyte migration through the first component.

10 . The device of claim 1 , wherein
the device has a through plane electrical resistivity that is less than 0.0017 mVmill at approximately 100 psi axial load and 100ASF; and a through plane thermal conductivity that is greater than 7 W/mK and less than 12 W/mK at approximately 140 psi.

11 . The device of claim 1 , wherein the second component is between 30% and 75% porous.

12 . The device of claim 1 , wherein pores of the second component have a size between 3 microns and 20 microns.

13 . The device of claim 1 , wherein the first component includes a rib on each of at least two edges of the pocket;
the ribs have a height; the second component has a thickness in a direction between the first and second sides of the second component; and the height is approximately equal to the thickness.

14 . The device of claim 1 , wherein the first component includes a rib on each of two edges of the pocket;
the ribs are parallel to the second plurality of fluid flow channels; and a seal member is situated on each of the ribs.

15 . The device of claim 14 , wherein each seal member includes a flap portion extending laterally outward beyond an edge of the corresponding rib.

16 . The device of claim 14 , wherein
the first plurality of fluid flow channels are generally perpendicular to the ribs; a first component seal member is situated on each laterally outermost edge of the second side of the first component; and the first component seal members are parallel to the first plurality of fluid flow channels.

17 . A method of making a fuel cell electrolyte management device, the method comprising:
forming a first component from a first mixture comprising a first type of graphite and a first resin, the first component having a first density; providing the first component with a pocket on a first side of the first component; forming a second component from a second mixture comprising a second type of graphite and a second resin, the second component having a second density that is less than the first density, the second component having a porosity that is configured to store electrolyte in the second component; situating the second component in the pocket with a first side of the second component received directly against the first side of the first component; and providing fluid flow channels on each of the first component and the second component.

18 . The method of claim 17 , wherein
forming the first component comprises
pressing the first mixture into a first preform using a pressure of 4000 psi at ambient temperature;
subsequently pressing the preform using a pressure of 800 psi at a temperature of 550° F. for about an hour;
subsequently pressing the preform using a pressure of 800 psi at a temperature of 140° F. for about an hour; and
forming the second component comprises
pressing the second mixture into a second preform using a pressure of 200 psi at 180° C. for about 30 minutes; and
subsequently converting the second resin to carbon by heating the second preform at a temperature of about 900° C. while the second preform is exposed to an inert gas.

19 . The method of claim 17 , wherein
providing the first component with the pocket comprises at least one of machining a portion of the first component away to establish the pocket; or forming the pocket during the forming of the first component.

20 . The method of claim 17 , wherein
the first density is at least 2 gm/cm 3 ; and the second component is between 30% and 75% porous.

21 . The method of claim 17 , comprising
at least temporarily bonding the second component to the pocket by an adhesive that decomposes at a temperature above an ambient or room temperature.

22 . The method of claim 17 , comprising
placing an adhesive along a border of the pocket; and at least temporarily bonding the second component to the pocket using the adhesive.

23 . The method of claim 17 , wherein
the second mixture comprises a wax that vaporizes at an elevated temperature; and the second component has pores in locations occupied by the wax prior to the wax vaporizing.

24 . The method of claim 17 , wherein
the device has a through plane electrical resistivity that is less than 0.0017 mVmill at 100 psi axial load and 100ASF; and a through plane thermal conductivity that is greater than 7 W/mK and less than 12 W/mK at approximately 140 psi.

25 . The method of claim 17 , wherein
the first mixture comprises about 85% flake graphite and about 15% fluoropolymer resin by mass; and the second mixture comprises about 80% non-flake graphite and about 20% thermosetting polymeric resin by mass.

Assignees

• Doosan Fuel Cell America Inc

Inventors

• Arpin Kevin A
• Bajorek William
• Johnson Andrew
• Kanuri Sridhar
• Livaich Eric
• O'Brien Eric
• Patterson Timothy

Classifications

• H01M8/086

  Phosphoric acid fuel cells [PAFC] · CPC title

• H01M8/04276 Primary

  Arrangements for managing the electrolyte stream, e.g. heat exchange · CPC title

• H01M2300/0008

  Phosphoric acid-based · CPC title

• H01M8/0289

  Means for holding the electrolyte (solid polymer electrolytes H01M8/1018) · CPC title

• Y02E60/50

  Fuel cells · CPC title