Electrolyzer cell arrangement

• US 20050115825A1
• Filed: 09/21/2004
• Published: 06/02/2005
• Est. Priority Date: 09/22/2003
• Status: Abandoned Application

• Current Assignee: Hydrogenics, U.S.A., Inc. (Cummins Incorporated)
• Original Assignee: Hydrogenics, U.S.A., Inc. (Cummins Incorporated)
• Inventors: Frank, David, Joos, Nathaniel Ian
• Application Number:
  US10/944,835
• Publication Number:
  US 20050115825A1
• Time in Patent Office: Days
• US Class Current: 204/253
• CPC Class Codes: C25B 15/08 Supplying or removing reactants or electrolytes; Regeneration of electrolytes
• CPC Class Codes: C25B 9/17 Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof
• CPC Class Codes: C25B 9/23 comprising ion-exchange membranes in or on which electrode material is embedded
• CPC Class Codes: C25B 9/70 Assemblies comprising two or more cells
• CPC Class Codes: C25B 9/77 having diaphragms
• CPC Class Codes: H01M 8/0245 in the form of layered or coated products
• CPC Class Codes: H01M 8/0247 characterised by the form characterised by a channel configuration H01M8/0258
• CPC Class Codes: H01M 8/025 semicylindrical
• CPC Class Codes: H01M 8/0254 corrugated or undulated
• CPC Class Codes: H01M 8/026 characterised by grooves, e.g. their pitch or depth
• CPC Class Codes: H01M 8/0263 having meandering or serpentine paths
• CPC Class Codes: H01M 8/0276 Sealing means characterised by their form H01M8/0273 takes precedence
• CPC Class Codes: H01M 8/04007 related to heat exchange
• CPC Class Codes: H01M 8/04074 Heat exchange unit structures specially adapted for fuel cell
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/1007 with both reactants being gaseous or vaporised H01M8/12 takes precedence
• CPC Class Codes: H01M 8/2483 characterised by internal manifolds
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

Some embodiments of the present invention provide electrolyzer cells in which distribution of water over the surface of an electrolyte layer (e.g. a MEA) is improved. Specifically, some embodiments provide an electrolyzer cell, including a flow field plate arranged in combination with at least two porous metal layers having smooth and flat surfaces, in which water is more uniformly distributed across an active surface of an electrolyte layer, which in turn may lead to a more uniform reaction rate over the active area of the electrolyte layer. Other related embodiments also include simplifications that may reduce costs related to manufacturing and assembly of electrochemical cells.

Claims

1. An electrolyzer cell comprising:

an anode flow field plate;

a cathode flow field plate;

an electrolyte layer arranged between the anode and cathode flow field plates; and

,

first and second screens arranged between the anode flow field plate and the electrolyte layer, wherein each of the screens has a respective number of openings and is electrically conductive.

2. An electrolyzer cell according to claim 1, wherein the first screen is adjacent the electrolyte layer.

3. An electrolyzer cell according to claim 2, wherein the openings of the first screen are smaller than those of the second screen.

4. An electrolyzer cell according to claim 3, wherein the spacing between the openings of the first screen is less than the spacing between the openings of the second screen.

5. An electrolyzer cell according to claim 1, wherein the size of the openings of the first screen is in the range of 0.004″

-0.025″

.

6. An electrolyzer cell according to claim 5, wherein the size of the openings of the second screen is in the range of 0.020″

-0.040″

.

7. An electrolyzer cell according to claim 1, wherein the first screen is thinner than the second screen.

8. An electrolyzer cell according to claim 1, wherein the thickness of the first screen is less than or equal to 0.003 inches.

9. An electrolyzer cell according to claim 8, wherein the thickness of the second screen is less than or equal to 0.01 inches.

10. An electrolyzer cell according to claim 1, wherein the openings of the first and second screens have a shape that is at least one hexagonal, circular, square, and triangular.

11. An electrolyzer cell according to claim 1, wherein a maximum dimension of the openings of the first screen is approximately 0.017 inches.

12. An electrolyzer cell according to claim 11, wherein a maximum dimension of the openings of the second screen is approximately 0.0254 inches.

13. An electrolyzer cell according to claim 1, wherein the spacing between the openings of the first screen is less than or equal to 0.005 inches.

14. An electrolyzer cell according to claim 13, wherein the spacing between the openings of the second screen is less than or equal to 0.01 inches.

15. An electrolyzer cell according to claim 1, wherein at least one of the anode flow field plate and the cathode flow field plate comprises:

a plurality of manifold apertures; and

,

a flow field, fluidly connecting two of the manifold apertures, having a plurality of open-faced flow channels that are all substantially the same length and arranged to uniformly distribute both a first process gas/fluid and heat produced by an electrochemical reaction involving the first process gas/fluid over an area covered by the flow field.

16. An electrolyzer cell according to claim 15, wherein some of the manifold apertures have the same area.

17. An electrolyzer cell according to claim 15, wherein some of the manifold apertures have the same dimensions.

18. An electrolyzer cell according to claim 15, wherein the anode and cathode flow field plates are circular in shape and each has a central region and a peripheral region surrounding the central region, wherein a flow field is arranged within the central region and the plurality of manifold apertures is arranged in the peripheral region.

19. An electrolyzer cell according to claim 18, wherein each of the open-faced flow channels include, in sequence, a first straight portion in fluid communication with a first one of the manifold apertures, a tortuous portion, an arc portion, and a second straight portion in fluid communication with a second one of the manifold apertures.

20. An electrolyzer cell according to claim 15, wherein the anode and cathode flow field plates are rectangular in shape and the open-faced channels are comprised of a plurality of substantially straight and parallel primary flow channels that extend along the length of the flow field plate.

21. An electrolyzer cell according to claim 15, wherein some of the manifold apertures are used to supply or evacuate process gases/fluids and each of these manifold apertures has substantially the same area as the other manifold apertures also used to supply or evacuate process gases/fluids.

22. An electrolyzer cell according to claim 21, wherein all of the manifold apertures used to supply or evacuate respective process gases/fluids also have substantially identical dimensions.

23. An electrolyzer cell according to claim 1, wherein at least one of the anode and cathode flow field plates comprises:

a coolant flow field, on a rear surface, having a plurality of open-faced flow channels that are all substantially the same length and arranged to uniformly distribute coolant on the rear surface.

24. An electrolyzer cell according to claim 1, wherein at least one of the anode and cathode flow field plates comprises:

a first slot, extending through the flow field plate, that is in fluid communication with open-faced flow channels on a front surface and in fluid communication with a first manifold aperture on a rear surface; and

,

a second slot, extending through the flow field plate, that is in fluid communication with the open-faced flow channels on the front surface and in fluid communication with a second manifold aperture on the rear surface.

25. An electrolyzer cell according to claim 24, wherein at least one of the anode and cathode flow field plates comprises:

a first set of aperture extensions extending from the first manifold aperture to the first slot, over a portion of the rear surface; and

,

a second set of aperture extensions extending from the second manifold aperture to the second slot, over a portion of the rear surface.

26. An electrochemical cell comprising:

a first flow field plate;

a second flow field plate;

an electrolyte layer arranged between the first and second flow field plates; and

,

first and second screens arranged between the first flow field plate and the electrolyte layer, wherein each of the screens has a respective number of openings.

27. An electrochemical cell stack, having at least one electrochemical cell comprising:

a first flow field plate;

a second flow field plate;

an electrolyte layer arranged between the first and second flow field plates; and

,

first and second screens arranged between the first flow field plate and the electrolyte layer, wherein each of the screens has a respective number of openings.

28. An electrochemical cell stack according to claim 27, wherein at least one of the first and second flow field plates comprises:

a plurality of manifold apertures; and

,

a flow field, fluidly connecting two of the manifold apertures, having a plurality of open-faced flow channels that are all substantially the same length and arranged to uniformly distribute both a first process gas/fluid and heat produced by an electrochemical reaction involving the first process gas/fluid over an area covered by the flow field.

29. An electrochemical cell stack according to claim 28, wherein some of the manifold apertures have the same area.

30. An electrochemical cell stack according to claim 28, wherein the first and second flow field plates are circular in shape and each has a central region and a peripheral region surrounding the central region, wherein a flow field is arranged within the central region and the plurality of manifold apertures are arranged in the peripheral region.

31. An electrochemical cell stack according to claim 30, wherein each of the open-faced flow channels include, in sequence, a first straight portion in fluid communication with a first one of the manifold apertures, a tortuous portion, an arc portion, and a second straight portion in fluid communication with a second one of the manifold apertures.

32. An electrochemical cell stack according to claim 28, wherein the first and second flow field plates are rectangular in shape and the open-faced flow channels are comprised of a plurality of substantially straight and parallel primary flow channels that extend along the length of the flow field plate.

33. An electrochemical cell stack according to claim 28, wherein some of the manifold apertures are used to supply or evacuate process gases/fluids and each of these manifold apertures has substantially the same area as the other manifold apertures also used to supply or evacuate process gases/fluids.

34. An electrochemical cell stack according to claim 33, wherein all of the manifold apertures used to supply or evacuate respective process gases/fluids also have substantially identical dimensions.

35. An electrochemical cell stack according to claim 28, wherein at least one of the first and second flow field plates comprises:

a coolant flow field, on a rear surface, having a plurality of open-faced flow channels that are all substantially the same length and arranged to uniformly distribute coolant on the rear surface.

36. An electrochemical cell stack according to claim 28, wherein at least one of the first and second flow field plates comprises:

a first slot, extending through the flow field plate, that is in fluid communication with open-faced flow channels on a front surface and in fluid communication with a first manifold aperture on a rear surface; and

a second slot, extending through the flow field plate, that is in fluid communication with the open-faced flow channels on the front surface and in fluid communication with a second manifold aperture on the rear surface.