Systems, apparatus and methods for isolating, compressing and/or retaining the structure of a fuel cell stack

• US 6,862,801 B2
• Filed: 11/30/2001
• Issued: 03/08/2005
• Est. Priority Date: 11/30/2001
• Status: Expired due to Fees

• Current Assignee: Ford Motor Company, Daimler AG (Mercedes-Benz Group AG)
• Original Assignee: Ballard Power Systems Corporation (Superior Plus Corporation)
• Inventors: Johnston Bailey, Ross William, Hill, Graham Edward, Pfister, Uwe, Hartwell, Rae
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US09/999,178
• Publication Number:
  US 20030104260A1
• Time in Patent Office: 1,194 Days
• Field of Search: 429/32, 429/35, 296/231, 296/232, 297/30
• US Class Current: 29/730
• CPC Class Codes: H01M 8/2404 Processes or apparatus for grouping fuel cells
• CPC Class Codes: H01M 8/2475 Enclosures, casings or containers of fuel cell stacks
• CPC Class Codes: H01M 8/248 Means for compression of the fuel cell stacks
• CPC Class Codes: H01M 8/249 comprising two or more groupings of fuel cells, e.g. modular assemblies
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10T 29/49108 Electric battery cell making
• CPC Class Codes: Y10T 29/4911 including sealing
• CPC Class Codes: Y10T 29/53135 Storage cell or battery

Abstract

A receptacle having an end cap, a pliable sidewall, and a fastener, for receiving and retaining a fuel cell stack in its stacked configuration during fabrication of a multi-stack fuel cell assembly, is shown and described. Methods of fabricating the assembly include stacking the fuel cell in the receptacle, compressing the fuel cell, and engaging the fastener to retain the stack in its stacked configuration and, or to retain the stack under at least partial compression.

Claims

1. A method for fabricating a fuel cell stack, comprising:

placing a stack of fuel cell elements in an open end of a pliable bag having the open end, an opposing closed end and a sidewall therebetween;

compressing the fuel cell stack;

extending a length of material over the compressed stack and across the open end of the bag; and

attaching the length of material to the bag to retain the fuel cell stack in its stack configuration.

2. The method of claim 1 wherein placing a stack of fuel cell elements in the open end of the bag comprises separately placing each fuel cell element into the bag, one at a time.

3. The method of claim 1 wherein placing a stack of fuel cell elements in the open end of the bag comprises separately placing groups of fuel cell elements into the bag, one group at a time.

4. The method of claim 1 wherein placing a stack of fuel cell elements in the open end of the bag comprises placing the fuel cell stack onto a buss plate, then lowering the buss plate into the bag.

5. The method of claim 1, further comprising first placing a sealing element against the closed end of the bag such that the fuel cell element abutting the closed end of the bag is in sealing contact therewith.

6. The method of claim 1 wherein compressing the fuel cell stack comprises compressing the fuel cell stack while the stack is in the bag.

7. The method of claim 1 wherein the open end of the bag has a tab projecting therefrom, and wherein extending a length of material over the compressed stack and across the open end of the bag comprises folding the tab from a first location on the sidewall of the bag to a second location on the sidewall of the bag opposite the first location.

8. The method of claim 1 wherein the open end of the bag has a plurality of tabs projecting therefrom, and wherein extending a length of material over the compressed stack and across the open end of the bag comprises folding the plurality of tabs, each from a first location on the sidewall of the bag to a second location on the sidewall of the bag opposite the first location.

9. The method of claim 1 wherein extending a length of material over the compressed stack and across the open end of the bag comprises extending a band of material from the closed end of the bag.

10. The method of claim 1 wherein extending a length of material over the compressed stack and across the open end of the bag comprises extending a band of material to the closed end of the bag.

11. The method of claim 1 wherein extending a length of material over the compressed stack and across the open end of the bag comprises extending a band of material from a first location on the closed end of the bag to a second location on the closed end of the bag.

12. The method of claim 1 wherein extending a length of material over the compressed stack and across the open end of the bag comprises folding a portion of the sidewall across the stack.

13. The method of claim 1 wherein the bag further comprises a second closed end, and wherein extending a length of material over the compressed stack comprises placing the second closed end over the stack.

14. The method of claim 1 wherein attaching the length of material to the bag to retain the fuel cell stack in its stack configuration comprises tensioning the length of material such that the fuel cell stack remains at least partially compressed.

15. The method of claim 1 wherein the sidewall of the pliable bag has a height less than a corresponding height of the stack of fuel cells, and wherein extending a length of material over the compressed stack and across the open end of the bag comprises engaging a cap having a sleeve depending therefrom over the top of the stack of fuel cells such that the sleeve of the cap overlaps the sidewall of the pliable bag.

16. The method of claim 1 wherein the sidewall of the pliable bag has a height less than a corresponding height of the stack of fuel cells, and wherein extending a length of material over the compressed stack and across the open end of the bag comprises engaging a cap having a sleeve depending therefrom over the top of the stack of fuel cells such that the sleeve of the cap overlaps the sidewall of the pliable bag, and further comprising taping the sidewall of the bag to the sleeve on the cap to retain the stack in its stacked configuration.

17. The method of claim 1 wherein the sidewall of the pliable bag has a height less than a corresponding height of the stack of fuel cells, and wherein extending a length of material over the compressed stack and across the open end of the bag comprises engaging a cap having a sleeve depending therefrom over the top of the stack of fuel cells such that the sleeve of the cap overlaps the sidewall of the pliable bag, and further comprising tensioning the sidewall and the sleeve away from their respective ends and taping the sidewall of the bag to the sleeve on the cap to retain the stack in its stacked configuration under at least partial compression.

18. A method for assembling a plurality of fuel cells, comprising:

compressing each of the fuel cell stacks;

wrapping a pliable material around each of the stacks of fuel cells to retain the stacks in their stacked configuration; and

placing the plurality of stacks between a pair of manifolds.

19. The method of claim 18 wherein the pliable material is an electrically insulative material, and wherein wrapping the material around each of the stacks comprises covering a sidewall of the stack that faces an adjacent stack when the stacks are positioned between the pair of manifolds.

20. The method of claim 18, further comprising pressure testing each of the stacks prior to placing the stacks between the pair of manifolds.

21. The method of claim 18 wherein wrapping a material around each of the stacks comprises tensioning the material to retain the stack under at least partial compression.

22. The method of claim 18 wherein wrapping the fuel cell stacks comprises first partially wrapping the fuel cell stacks prior to compressing them, then completing the wrapping to encircle at least a portion of the stack.

23. The method of claim 18 wherein wrapping the fuel cell stacks comprises encasing each stack in a bottom cap and sidewalls, and extending a length of material over the stack from one portion of the sidewall to another portion of the sidewall.

24. The method of claim 18 wherein wrapping the fuel cell stacks comprises encasing each stack in a bottom cap and sidewalls, and extending a plurality of lengths of material over the stack from one portion of the sidewall to another portion of the sidewall.

25. The method of claim 18 wherein wrapping the fuel cell stacks comprises encasing each stack in a bottom cap and sidewalls, and folding a portion of the sidewall across the stack to an opposing portion of the sidewall.

26. The method of claim 18 wherein wrapping the fuel cell stacks comprises encasing one end of each stack in a bottom cap having sidewalls depending therefrom, and engaging the other end of each stack in a top cap having a sleeve depending therefrom, such that at least a portion of the sleeve overlaps at least a portion of the sidewall.

27. The method of claim 18 wherein wrapping the fuel cell stacks comprises forming sidewalls to closely conform with each stack, coupling the sidewalls to an end cap, and folding a portion of the sidewall across the stack to an opposing portion of the sidewall.

28. The method of claim 18 wherein wrapping the fuel cell stacks comprises forming sidewalls to closely conform with each stack and coupling the sidewalls to an end cap.

29. The method of claim 18, further comprising taping one portion of the material to another portion of the material to retain the material in close conformity with the stack.

30. The method of claim 18, further comprising tensioning the material around at least a portion of each of the stacks, then taping one portion of the material to another portion of the material to retain the stack in at least partial compression.

31. A receptacle for receiving and retaining a fuel cell stack in its stacked configuration during fabrication of a multi-stack fuel cell assembly having a manifold, the receptacle comprising:

an end cap having a plurality of openings therein configured to allow the fuel cell stack to communicate with a corresponding plurality of openings in the manifold;

a pliable sidewall sized and shaped to insulate the fuel cell stack from at least one adjacent fuel cell stack when the multi-stack fuel cell assembly has been assembled; and

a fastener configured to extend from one location on the sidewall across the end of the fuel cell stack opposite the end cap and to be attached to another location on the sidewall to retain the fuel cell stack in its stacked configuration.

32. The receptacle of claim 31 wherein the end cap is formed to conform to the shape of an end of the fuel cell stack.

33. The receptacle of claim 31 wherein the end cap comprises a thermoplastic resin that is vacuum formed to conform to the shape of and end of the fuel cell stack.

34. The receptacle of claim 31 wherein an internal surface of the end cap comprises a seal around at least one of the openings, the seal being configured to sealably engage a port on the fuel cell stack to reduce the likelihood of leakage between the fuel cell stack and the manifold.

35. The receptacle of claim 31 wherein the sidewall is coupled to the end cap.

36. The receptacle of claim 31 wherein the sidewall is configured to encircle at least a substantial portion of a corresponding sidewall on the fuel cell stack.

37. The receptacle of claim 31 wherein the fastener comprises an elongated band of pliable material having a length sufficient to extend across the top of the fuel cell stack and overlap an opposing portion of the sidewall.

38. The receptacle of claim 31 wherein the fastener comprises a plurality of elongated bands of pliable material, each band having a length sufficient to extend across the top of the fuel cell stack and overlap an opposing portion of the sidewall.

39. The receptacle of claim 31 wherein the fastener comprises a portion of the sidewall sufficiently tall to project beyond a corresponding top of the fuel cell stack when the fuel cell stack is engaged with the receptacle, such that the portion of the sidewall can be folded across the top of the fuel cell stack and overlap at least a portion of an opposing portion of the sidewall.