Fuel cell stack

• US 7,163,761 B2
• Filed: 11/14/2002
• Issued: 01/16/2007
• Est. Priority Date: 11/14/2002
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Herdtle, Thomas, Schleif, Larry Allan, Steinbach, Andrew James, Debe, Mark Kevitt
• Primary Examiner(s): Crepeau; Jonathan
• Application Number:
  US10/294,224
• Publication Number:
  US 20040096724A1
• Time in Patent Office: 1,524 Days
• Field of Search: None
• US Class Current: 429/469
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 8/0206 Metals or alloys
• CPC Class Codes: H01M 8/0267 having heating or cooling means, e.g. heaters or coolant flow channels
• CPC Class Codes: H01M 8/0297 Arrangements for joining electrodes, reservoir layers, heat exchange units or bipolar separators to each other H01M8/0271 takes precedence
• CPC Class Codes: H01M 8/04007 related to heat exchange
• CPC Class Codes: H01M 8/242 comprising framed electrodes or intermediary frame-like gaskets H01M8/2425, H01M8/244 take precedence
• CPC Class Codes: H01M 8/2465 Details of groupings of fuel cells
• CPC Class Codes: H01M 8/248 Means for compression of the fuel cell stacks
• CPC Class Codes: H01M 8/2483 characterised by internal manifolds
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A fuel cell stack is provided comprising fuel cell modules least compression plates; and at least one plurality of mechanical linkages connecting a pair of compression plates located on either side of at least one fuel cell module, which may be engaged to maintain a predetermined gap distance between the pair of compression plates. The present invention additionally provides a fuel cell stack comprising: fuel cell modules stacked alternately with compression plates; mechanical linkages connecting a first pair of compression plates directly adjacent to a first fuel cell module; mechanical linkages connecting a second pair of compression plates directly adjacent to a second fuel cell module; where a) the first and second fuel cell modules may be maintained under compression, and b) the compression on each fuel cell module may be adjusted essentially independently of the compression on the other.

Claims

1. A fuel cell stack comprising:

one or more fuel cell modules, each fuel cell module comprising at least one membrane electrode assembly, said membrane electrode assembly comprising no hard stop layer;

two or more compression plates; and

at least one plurality of mechanical linkages connecting at least one pair of compression plates located on either side of at least one fuel cell module, which may be engaged to maintain a predetermined gap distance between said pair of compression plates;

wherein said plurality of mechanical linkages comprises a mechanical linkage which comprises a latch attached to a first compression plate at a first attachment point on said first compression plate and attached to a second compression plate at a second attachment point on said second compression plate, said mechanical linkage having an effective length being the distance between said first and second attachment points, said latch being attached by an adjustable attachment to at least one of said first and second compression plates such that the effective length of said mechanical linkage may be varied by adjustment of said adjustable attachment;

wherein said adjustable attachment comprises an offset cam mechanism.

2. The fuel cell stack according to claim 1 wherein said offset cam mechanism comprises a cam bolt passing through a first hole in said latch and into a first hole in a compression plate, wherein said cain bolt comprises an offset cam adapted to contact an inner surface of said first hole in said latch, and wherein said cam bolt may be rotated by application of suitable torque.

3. A fuel cell stack comprising:

one or more fuel cell modules, each fuel cell module comprising at least one membrane electrode assembly, said membrane electrode assembly comprising no hard stop layer;

two or more compression plates; and

at least one plurality of mechanical linkages connecting at least one pair of compression plates located on either side of at least one fuel cell module, which may be engaged to maintain a predetermined gap distance between said pair of compression plates;

wherein said plurality of mechanical linkages comprises a mechanical linkage which comprises a latch attached to a first compression plate at a first attachment point on said first compression plate and attached to a second compression plate at a second attachment point on said second compression plate, said mechanical linkage having an effective length being the distance between said first and second attachment points, said latch being attached by an adjustable attachment to at least one of said first and second compression plates such that the effective length of said mechanical linkage may be varied by adjustment of said adjustable attachment;

wherein said latch is attached to one of said first and second compression plates by a non-adjustable attachment;

wherein said non-adjustable attachment comprises a bolt passing through a second hole in said latch and into a first hole in one of said first and second compression plates.

4. A fuel cell stack comprising:

two or more fuel cell modules, each fuel cell module comprising at least one membrane electrode assembly;

three or more compression plates stacked alternately with said fuel cell modules;

a first plurality of mechanical linkages connecting a first pair of compression plates which are directly adjacent to, and on either side of, a first fuel cell module; and

a second plurality of mechanical linkages connecting a second pair of compression plates which are directly adjacent to, and on either side of a second fuel cell module;

wherein one compression plate is common to said first and second pairs of compression plates;

wherein said first and second fuel cell modules may be maintained under compression and wherein the compression on each of said first and second fuel cell modules may be adjusted essentially independently of the compression on the other of said first and second fuel cell modules;

wherein said plurality of mechanical linkages comprises a mechanical linkage which comprises a latch attached to a first compression date at a first attachment point on said first compression plate and attached to a second compression plate at a second attachment point on said second compression plate, said mechanical linkage having an effective length being the distance between said first and second attachment points, said latch being attached by an adjustable attachment to at least one of said first and second compression plates such that the effective length of said mechanical linkage may be varied by adjustment of said adjustable attachment;

wherein said adjustable attachment comprises an offset cam mechanism.

5. The fuel cell stack according to claim 4 wherein said offset cam mechanism comprises a cam bolt passing through a first hole in said latch and into a first hole in a compression plate, wherein said cam bolt comprises an offset cam adapted to contact an inner surface of said first hole in said latch, and wherein said cain bolt may be rotated by application of suitable torque.

6. A fuel cell stack comprising:

two or more fuel cell modules, each fuel cell module comprising at least one membrane electrode assembly;

three or more compression plates stacked alternately with said fuel cell modules;

a first plurality of mechanical linkages connecting a first pair of compression plates which are directly adjacent to, and on either side of, a first fuel cell module; and

a second plurality of mechanical linkages connecting a second pair of compression plates which are directly adjacent to, and on either side of a second fuel cell module;

wherein one compression plate is common to said first and second pairs of compression plates;

wherein said first and second fuel cell modules may be maintained under compression and wherein the compression on each of said first and second fuel cell modules may be adjusted essentially independently of the compression on the other of said first and second fuel cell modules;

wherein said plurality of mechanical linkages comprises a mechanical linkage which comprises a latch attached to a first compression plate at a first attachment point on said first compression plate and attached to a second compression plate at a second attachment point on said second compression plate, said mechanical linkage having an effective length being the distance between said first and second attachment points, said latch being attached by an adjustable attachment to at least one of said first and second compression plates such that the effective length of said mechanical linkage may be varied by adjustment of said adjustable attachment;

wherein said latch is attached to one of said first and second compression plates by a non-adjustable attachment;

wherein said non-adjustable attachment comprises a bolt passing through a second hole in said latch and into a first hole in one of said first and second compression plates.