Proton exchange membrane fuel cell power system

• US 6,030,718 A
• Filed: 11/20/1997
• Issued: 02/29/2000
• Est. Priority Date: 11/20/1997
• Status: Expired due to Term

• Current Assignee: Emergent Power Inc. (Plug Power Inc.)
• Original Assignee: Avista Corporation (Avistar)
• Inventors: De Vries, Peter David, Lott, David R., Fuglevand, William A., Bayyuk, Shiblihanna I., Scartozzi, John P., Somers, Gregory M., Stokes, Ronald G., Lloyd, Greg Alden
• Primary Examiner(s): KALAFUT, STEPHEN J
• Application Number:
  US08/979,853
• Time in Patent Office: 831 Days
• Field of Search: 429/26, 429/32, 429/37, 429/42, 429/66
• US Class Current: 429/410
• CPC Class Codes: H01M 8/0247 characterised by the form characterised by a channel configuration H01M8/0258
• CPC Class Codes: H01M 8/04097 with recycling of the reactants H01M8/04119, H01M8/04104 take precedence
• CPC Class Codes: H01M 8/04141 by water containing exhaust gases
• CPC Class Codes: H01M 8/04335 of cathode reactants at the inlet or inside the fuel cell
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/04835 of fuel cell reactants
• CPC Class Codes: H01M 8/2475 Enclosures, casings or containers of 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

Abstract

A proton exchange membrane fuel cell power system for producing electrical power is described and which includes a plurality of discrete fuel cell modules having at least two membrane electrode diffusion assemblies, each of the membrane electrode diffusion assemblies having opposite anode and cathode sides; a pair of current collectors are individually disposed in juxtaposed ohmic electrical contact with opposite anode and cathode sides of each of the membrane electrode diffusion assemblies; and individual force application assemblies apply a given force to the pair current collectors and the individual membrane electrode diffusion assemblies. The proton exchange membrane fuel cell power system also includes an enclosure mounting a plurality of subracks which receive the discrete fuel cell modules. Additionally, a control system is disclosed which optimizes the performance parameters of the discrete proton exchange membrane fuel cell modules.

Claims

1. A proton exchange membrane fuel cell power system comprising:

a plurality of discrete proton exchange membrane fuel cell modules which are self-humidifying and which produce heat energy, and wherein each of the discrete fuel cell modules has a cathode air flow, and a preponderance of the heat energy is removed from the discrete proton exchange membrane fuel cell modules by the cathode air flow.

2. A power system as claimed in claim 1, wherein each discrete proton exchange membrane fuel cell module has at least two membrane electrode diffusion assemblies which have opposite anode and cathode sides, and wherein each PEM fuel cell module can be manipulated by hand.

3. A power system as claimed in claim 2, wherein each discrete proton exchange membrane fuel cell module has a pair of current collectors which are individually disposed in juxtaposed ohmic electrical contact with the opposite anode and cathode sides of each of the membrane electrode diffusion assemblies.

4. A power system as claimed in claim 3, wherein the discrete proton exchange membrane fuel cell modules have individual force application assemblies for applying a force to each pair of current collectors and the individual membrane electrode diffusion assemblies associated therewith.

5. A power system as claimed in claim 3, wherein the individual current collectors comprise:

a base substrate which is electrically conductive and which has a surface area of which at least about 70% is open area, and wherein the base substrate is selected from the group consisting essentially of nickel, copper, and stainless steel; and

a coating applied over the base substrate and which is electrically conductive, galvanically cathodic and oxygen-stable.

6. A power system as claimed in claim 1, wherein the discrete proton exchange membrane fuel cell modules have an active area having a surface area, and wherein each proton exchange membrane fuel cell module produces a current density of at least about 350 mA per square centimeter of active area at a nominal voltage of at least about 0.5 volts.

7. A power system as claimed in claim 1, wherein each discrete proton exchange membrane fuel cell module comprises:

a hydrogen distribution frame defining discrete, substantially opposed cavities and wherein the respective membrane electrode diffusion assemblies are individually sealably mounted in each of the cavities, and wherein the hydrogen distribution frame is oriented between the individual membrane electrode diffusion assemblies;

a cathode cover which releasably cooperates with the hydrogen distribution frame and which partially occludes each cavity;

a pair of current collectors received in each of the cavities of the hydrogen distribution frame;

a pressure transfer assembly cooperating with the cathode cover and which engages the current collector which is in ohmic electrical contact with the cathode side of the membrane electrode diffusion assembly; and

a biasing member oriented between the cathode cover and the pressure transfer assembly, and wherein the pressure transfer assembly applies a force such that at least about 175 pounds per square inch is realized between the membrane electrode diffusion assembly and the associated pair of current collectors.

8. A power system as claimed in claim 7, wherein the hydrogen distribution frame defines a first passageway which facilitates the delivery of a source of hydrogen to the cavity and to the anode side of the membrane electrode diffusion assembly, and a second passageway which facilitates the removal of unreacted hydrogen gas, water and impurities from the cavity;

and wherein the cathode cover, and the pressure transfer assembly define a third passageway which facilitates the delivery of a source of ambient air to the cavity and to the cathode side of the membrane electrode diffusion assembly.

9. A power system as claimed in claim 2, wherein the membrane electrode diffusion assemblies each comprise:

a solid proton conducting electrolyte membrane having opposite anode and cathode sides;

individual catalytic anode and cathode electrodes disposed in ionic contact with the respective anode and cathode sides of the electrolyte membrane;

a first diffusion layer borne on the individual anode and cathode electrodes and which is positioned in ohmic electrical contact with each electrode, and wherein the first diffusion layer has a hydrophobic gradient; and

a second diffusion layer on the first diffusion layer and which is positioned in ohmic electrical contact with the underlying first diffusion layer.

10. A power system as claimed in claim 9, wherein the solid proton conducting electrolyte membrane comprises:

about 35% to about 50% by molar concentration of a methacrylate monomer;

about 30% to about 50% by molar concentration of an acrylate monomer;

about 25% to about 45% by molar concentration of a sulfonic acid monomer; and

about 5% to about 20% by molar concentration of a compatible crosslinking agent.

11. A power system as claimed in claim 1, and further comprising:

a housing defining a cavity;

a subrack mounted in the cavity and supporting the plurality of discrete proton exchange membrane fuel cell modules;

a fuel distribution assembly received in the housing and coupled in fluid flowing relation relative to the subrack, the fuel distribution assembly delivering a source of hydrogen to each of the proton exchange membrane fuel cell modules, and wherein the discrete proton exchange membrane fuel cell modules are releasably coupled in fluid flowing relation relative to the fuel distribution system;

a direct current bus mounted on the subrack, the individual proton exchange membrane fuel cell modules being releasably electrically coupled with the direct current bus;

a power conditioning assembly electrically coupled with the direct current bus and which receives and inverts the electrical power produced by each of the discrete proton exchange membrane fuel cell modules;

an air distribution assembly mounted on the subrack and coupled in fluid flowing relation to each of the proton exchange membrane fuel cell modules, the air distribution assembly having an intake end which receives a source of air that is to be delivered to each of the proton exchange membrane fuel cell modules, and an exhaust end which delivers the source of air to the discrete proton exchange membrane fuel cell modules, the source of air delivered to the proton exchange membrane fuel cell modules comprising the cathode air flow; and

a digital programmable controller electrically coupled with each of the proton exchange membrane fuel cell modules, fuel distribution assembly, power conditioning assembly, and the air distribution assembly.

12. A proton exchange membrane fuel cell power system for producing electrical power comprising:

a plurality of discrete fuel cell modules each having at least two membrane electrode diffusion assemblies, each of the membrane electrode diffusion assemblies having opposite anode and cathode sides;

a pair of current collectors each disposed in juxtaposed ohmic electrical contact with the opposite anode and cathode sides of each of the membrane electrode diffusion assemblies; and

individual force application assemblies for applying force to each pair of the current collectors and the individual membrane electrode diffusion assemblies.

13. A power system is claimed in claim 12, wherein the individually discrete fuel cell modules have an electrical efficiency of at least about 40%;

and wherein the discrete fuel cell modules can be manipulated by hand.

14. A power system as claimed in claim 12, wherein the individually discrete fuel cell modules are self-humidifying, and wherein each discrete fuel cell module produces a given amount of heat and has a cathode air flow, and wherein the cathode air flow removes a preponderance of the heat generated by each of the discrete fuel cell modules.

15. A power system as claimed in claim 12, wherein each of the membrane electrode diffusion assemblies has an active area which has a surface area, and wherein each of the discrete fuel cell modules produces a current density of at least about 350 mA per square centimeter of active area at a nominal cell voltage of about 0.5 volts D.C.

16. A power system as claimed in claim 12, wherein each discrete fuel cell modules each has an electrical output of at least about 10.5 watts.

17. A power system as claimed in claim 12, and further comprising:

an enclosure defining a cavity; and

a subrack mounted in the cavity and supporting the plurality of discrete fuel cell modules in a given orientation in the cavity.

18. A power system as claimed in claim 17, and wherein the enclosure further comprises:

a heat exchanger for capturing thermal energy emitted by the discrete fuel cell modules.

19. A power system as claimed in claim 17, and wherein the enclosure further comprises:

a digital programmable controller electrically coupled with each of the fuel cell modules.

20. A power system as claimed in claim 17, wherein the enclosure further comprises:

a fuel distribution assembly for delivering hydrogen to the individual discrete fuel cell modules;

an air distribution assembly for delivering air to the individual discrete fuel cell modules;

a direct current output bus; and

a power conditioning assembly for receiving and inverting the electrical power produced by each of the discrete fuel cell modules.

21. A power system as claimed in claim 20, wherein a plurality of subracks are mounted in the cavity, and wherein each of the subracks has a forward and rearward edge, and top and bottom portions, and wherein each of the fuel cell modules are operably coupled with the fuel distribution assembly, direct current output bus and the power conditioning assembly in the vicinity of the rearward edge of each of the subracks, and with the air distribution assembly at the top and bottom portions of each of the subracks.

22. A power system as claimed in claim 20, wherein the air distribution assembly further comprises:

a plenum constructed integrally with each of the subracks, the plenum having an exhaust end which delivers air to each of the fuel cell modules supported on the subrack, and an intake end which receives both air which has passed through each of the fuel cell modules, and air which comes from outside of the respective fuel cell modules;

an air movement assembly operably coupled to the plenum for moving the air along the plenum to the individual fuel cell modules; and

an air mixing valve operably coupled to the plenum and controlling the amount of air which has passed through the respective fuel cells and which is recirculated back to each of the fuel cell modules.

23. A power system as claimed in claim 20, wherein the power conditioning assembly comprises:

an inverter for converting direct current voltage to alternating current voltage.

24. A power system as claimed in claim 12, wherein the discrete fuel cell modules comprise:

a hydrogen distribution frame defining discrete cavities and wherein the respective membrane electrode diffusion assemblies are individually sealably mounted in each of the cavities, and wherein the hydrogen distribution frame is oriented between the individual membrane electrode diffusion assemblies.

25. A power system as claimed in claim 24, wherein the hydrogen distribution frame comprises multiple pairs of discretely opposed cavities.

26. A power system as claimed in claim 24, wherein the force application assemblies each comprise:

a cathode cover which partially occludes the respective cavities of the hydrogen distribution frame, the respective cathode covers individually releasably cooperating with each other and with the hydrogen distribution frame;

a pressure transfer assembly oriented in juxtaposed relation relative to one of the current collectors;

a biasing member oriented between the respective cathode covers and the pressure transfer assembly, and wherein the pressure transfer assembly applies a force such that at least about 175 pounds per square inch is realized between the membrane electrode diffusion assembly and the associated pair of current collectors.

27. A power system as claimed in claim 26, wherein the force application assembly further comprises a pressure distribution assembly juxtaposed relative to the pressure transfer assembly, and wherein the pressure distribution assembly comprises:

a substantially non-compressible and flexible substrate; and

a semi-rigid substantially non-elastic and compressible substrate mounted on the non-compressible substrate, and wherein the compressible substrate is in contact with the pressure transfer assembly, and the non-compressible substrate is in contact with the biasing member.

28. A power system as claimed in claim 27, wherein the substantially non-compressible substrate comprises a thin metal plate.

29. A power system as claimed in claim 27, wherein the compressible substrate comprises rigid foam manufactured from a synthetic polymeric material.

30. A power system as claimed in claim 27, wherein the pressure distribution assembly facilitates the substantial uniform delivery of force from the adjoining cathode cover to the membrane electrode diffusion assembly.

31. A power system as claimed in claim 24, wherein the hydrogen distribution frame further defines a first passageway which permits the delivery of hydrogen gas to each of the cavities and to the anode side of the membrane electrode diffusion assembly, and a second passageway which facilitates the removal of impurities, water and unreacted hydrogen from each of the cavities, and wherein each of the cathode covers and the respective force application assemblies define a third passageway which permits delivery of air to each of the cavities and to the cathode side of each of the respective membrane electrode diffusion assemblies.

32. A power system as claimed in claim 31, wherein the pressure transfer assembly is juxtaposed relative to the current collector which is disposed in ohmic electrical contact with the cathode side of the membrane electrode distribution assembly, and wherein the pressure transfer assembly defines a given open area between the adjacent current collector and the adjoining cathode cover, and wherein the open area defines, in part, the third passageway, and wherein the biasing member distributes the force transmitted by the respective cathode covers through the pressure transfer assembly.

33. A power system as claimed in claim 31, wherein the hydrogen gas is supplied by means of the first passageway to each of the cavities at a pressure of about 1 P.S.I.G. to about 10 P.S.I.G., and wherein the air is supplied at a substantially ambient, fan forced pressure.

34. A power system as claimed in claim 26, wherein the cathode covers are fabricated from a substrate having a flexural modulus of at least about 1.00 million pounds per square inch, and wherein the hydrogen distribution frame is fabricated from a substrate having a flexural modulus of less than about 500,000 pounds per square inch, and a compressive strength of less than about 20,000 pounds per square inch.

35. A power system as claimed in claim 26, wherein the cathode cover defines a passageway which facilitates the delivery of a cathode air flow to each of the fuel cell modules, and wherein each fuel cell module produces heat, and the preponderance of the heat is removed from the fuel cell modules by the cathode air flow.

36. A power system as claimed in claim 26, wherein the biasing member comprises metal wave springs which matingly cooperate with the adjoining cathode cover, and wherein the pressure transfer assembly comprises a main body having a plurality of resilient legs which exert force on the pair of current collectors and the membrane electrode diffusion assembly, and wherein the individual legs have a spring deflection of about 0.001 to about 0.004 inches.

37. A power system as claimed in claim 12, wherein the membrane electrode diffusion assemblies each comprise:

a solid proton conducting electrolyte membrane which has opposite anode and cathode sides;

individual catalytic anode and cathode electrodes disposed in ionic contact with the respective anode and cathode sides of the electrolyte membrane; and

a diffusion layer borne on each of the anode and cathode electrodes and which is electrically conductive and has a minimum porosity.

38. A power system as claimed in claim 37, wherein the diffusion layer further comprises:

a first diffusion layer borne on the individual anode and cathode electrodes and which is positioned in ohmic electrical contact with each electrode and which is electrically conductive and has a pore size; and

a second diffusion layer borne on the first diffusion layer and which is positioned in ohmic electrical contact with the underlying first diffusion layer, and which further is electrically conductive and has a pore size which is greater than the pore size of the first diffusion layer.

39. A power system as claimed in claim 37, wherein the electrolyte membrane has at least about a 20% molar concentration of a sulfonic acid monomer.

40. A power system as claimed in claim 37, wherein the electrolyte membrane comprises crosslinked polymeric chains incorporating sulfonic acid groups.

41. A power system as claimed in claim 40, wherein the crosslinked polymeric chains are formed from monomeric units which are selected from the group consisting essentially of:

poly (ethylene glycol) methacrylate, poly (propylene glycol) methacrylate, poly (ethylene glycol) ethyl ether methacrylate, and poly (propylene glycol) methyl ether methacrylate, hydroxpropyl methacrylate, 2-hydroxyethyl methacrylate, the acrylate analogs, and 4-hydroxybutyl acrylate.

42. A power system as claimed in claim 40, wherein the sulfonic acid monomers are selected from the group consisting essentially of:

3-alkoxy-2-hydroxy-1-propanesulfonic acid, 4-styrenesulfonic acid, vinylsulfonic acid, 3-sulfopropyl methacrylate, 3-sulfopropylacrylate and fluorinated derivatives thereof.

43. A power system as claimed in claim 40, wherein the crosslinking agent is selected from the group consisting essentially of:

ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, glycerol dimethacrylate, diallyloxyacetic acid; and

allylmethacrylate.

44. A power system as claimed in claim 37, wherein the electrolyte membrane comprises crosslinked copolymeric chains having sulfonic acid groups, and wherein the crosslinked copolymeric chains comprise methacrylate and a crosslinking agent.

45. A power system as claimed in claim 44, wherein the sulfonic acid groups are selected from the group consisting essentially of 3-alkoxy-2-hydroxy-1-propane sulfonic acid, 4-styrenesulfonic acid, vinyl sulfonic acid;

and 3-sulfopropyl methacrylate, 3-sulfopropylacrylate, and fluorinated derivatives thereof; and

the crosslinking agent is selected from the group consisting essentially of ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, glycerol dimethacrylate, diallyloxyacetic acid, allylmethacrylate and mixtures thereof.

46. A power system as claimed in claim 37, wherein the electrolyte membrane comprises:

about 35% to about 50% by molar concentration of a methacrylate monomer;

about 30% to about 50% by molar concentration of an acrylate monomer;

about 25% to about 45% by molar concentration of a sulfonic acid monomer; and

about 5% to about 20% by molar concentration of a compatible crosslinking agent.

47. A power system as claimed in claim 37, wherein the glass transition temperature of the electrolyte membrane is at least about 110 degrees C., and wherein the electrolyte membrane has a thickness of less than about 1 millimeter, and is substantially stable in the presence of water, and operational at temperatures of less than about 80 degrees C.

48. A power system as claimed in claim 46, and further comprising a compatible plasticizer.

49. A power system as claimed in claim 37, wherein the electrolyte membrane further comprises:

a porous supporting matrix which is made integral with the electrolyte membrane.

50. A power system as claimed in claim 49, wherein the porous supporting matrix does not reactively produce hydrogen ions and is not electrically conductive.

51. A power system as claimed in claim 49, wherein the porous supporting matrix is substantially inert, and has a porosity of about 30% to about 80%.

52. A power system as claimed in claim 49, wherein the electrolyte membrane has a given proton conductivity which is proportional to the porosity of the supporting matrix.

53. A power system as claimed in claim 37, wherein the solid electrolyte membrane comprises:

a polymethacrylate;

an acrylate or methacrylate;

a sulfonic acid;

a crosslinking agent; and

a compatible plasticizer.

54. A power system as claimed in claim 53, wherein the polymethacrylate is selected from the group consisting essentially of:

poly (ethylene glycol) methacrylate, poly (propylene glycol) methacrylate, poly (ethylene glycol) ethyl ether methacrylate, and poly (propylene glycol) methyl ether methacrylate; and

wherein the acrylate or methacrylate consists essentially of hydroxpropyl methacrylate, 2-hydroxyethyl methacrylate, the acrylate analogs, and 4-hydroxybutyl acrylate.

55. A power system as claimed in claim 53, wherein the polymethacrylate is about 20% to about 90% by weight.

56. A power system as claimed in claim 53, wherein the sulfonic acid is selected from the group consisting essentially of:

3-alkoxy-2-hydroxy-1-propanesulfonic acid, 4-styrenesulfonic acid, vinylsulfonic acid, 3-sulfopropyl methacrylate, 3-sulfopropylacrylate, and fluorinated derivatives thereof.

57. A power system as claimed in claim 56, wherein the sulfonic acid comprises about 25% to about 45% by molar concentration.

58. A power system as claimed in claim 53, wherein the crosslinking agent is selected from the group consisting essentially of:

ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, glycerol dimethacrylate, diallyloxyacetic acid, allylmethacrylate and mixtures thereof.

59. A power system as claimed in claim 58, wherein the crosslinking agent is about 5% to about 20% by molar concentration.

60. A power system as claimed in claim 37, wherein the solid proton conducting electrolyte membrane comprises:

at least about 10% to about 50% by molar concentration of a copolymer which has monomeric units which are selected from the group consisting essentially of poly (ethylene glycol) methacrylate, poly (propylene glycol) methacrylate, poly (ethylene glycol) ethyl ether methacrylate, poly (propylene glycol) methyl ether methacrylate, hydroxypropyl methacrylate, 2-hydroxyethyl methacrylate, acrylate analogs and 4-hydroxybutyl acrylate;

at least about 25% to about 45% by molar concentration of an acid selected from the group consisting essentially of 3-alkoxy-2-hydroxy-1-propanesulfonic acid, 4-styrenesulfonic acid, vinylsulfonic acid, 3-sulfopropyl methacrylate, 3-sulfopropylacrylate and fluorinated derivatives thereof;

at least about 5% to about 20% by molar concentration of a crosslinking agent selected from the group consisting essentially of ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, glycerol dimethacrylate, diallyloxyacetic acid, and allylmethacrylate;

a compatible plasticizer; and

a support matrix having a minimum porosity, and which is not electrically conductive.

61. A power system as claimed in claim 12, wherein the membrane electrode diffusion assemblies each comprise:

a solid proton conducting electrolyte membrane which has opposite anode and cathode sides;

individual catalytic anode and cathode electrodes formed on the proton conducting electrolyte membrane and which are in ionic contact therewith; and

a non-catalytic electrically conductive diffusion layer affixed on the anode and cathode electrodes and which is porous.

62. A power system as claimed in claim 61, wherein the non-catalytic electrically conductive diffusion layer has a first diffusion layer which is positioned in ohmic electrical contact with each of the electrodes;

and a second diffusion layer positioned in ohmic electrical contact with the underlying first diffusion layer.

63. A power system as claimed in claim 62, wherein the non-catalytic electrically conductive diffusion layer is borne on a third diffusion layer.

64. A power system as claimed in claim 62, wherein the first diffusion layer comprises a coating of particulate carbon suspended in a binding resin;

and the second diffusion layer comprises a porous hydrophobic carbon backing layer.

65. A power system as claimed in claim 64, wherein the binding resin is substantially hydrophobic and is selected from the group consisting essentially of fluorinated hydrocarbons;

and wherein the first diffusion layer has about 20% to about 90%, by weight, of the particulate carbon.

66. A power system as claimed in claim 64, wherein the porous hydrophobic backing layer forming the second diffusion layer is selected from the group consisting essentially of carbon cloth, carbon paper, or carbon sponge which has been rendered hydrophobic.

67. A power system as claimed in claim 66, wherein the hydrophobic backing layer is coated with a liquid suspension comprising about 95% to about 99% by weight of water;

and about 1% to about 5% by weight of a compatible surfactant.

68. A power system as claimed in claim 62, wherein the first diffusion layer is a composite coating formed of successive layers, each of the successive layers being hydrophobic, and wherein the first diffusion layer has a hydrophobic gradient, and wherein the hydrophobic gradient is established by adjusting the hydrophobicity of the successive layers forming the composite layer.

69. A power system as claimed in claim 68, wherein the successive layers closest to the second diffusion layer are the least hydrophobic of all of the successive layers.

70. A power system as claimed in claim 68, wherein the successive layers closest to the second diffusion layer are the most hydrophobic of all of the successive layers.

71. A power system as claimed in claim 61, wherein the diffusion layer has a variable porosity.

72. A power system as claimed in claim 61, wherein a thermoplastic binding agent is positioned between the anode and cathode electrodes and the overlying diffusion layer and is effective to bind the diffusion layer to the underlying anode and cathode electrode.

73. A power system as claimed in claim 72, wherein the thermoplastic binding agent is selected from the group consisting essentially of polyethylene or wax.

74. A power system as claimed in claim 61, wherein the individual anode and cathode electrodes include an electrolyte, and wherein the electrolyte and the solid proton conducting electrolyte membrane include a cross-linked copolymer incorporating sulfonic acid groups.

75. A power system as claimed in claim 61, wherein the individual anode and cathode electrodes comprise:

particulate carbon;

a catalyst; and

a cross-linked copolymer incorporating sulfonic acid groups.

76. A power system as claimed in claim 61, wherein the individual anode and cathode electrodes comprise:

a particulate carbon;

a catalyst;

a binding resin; and

a cross-linked copolymer incorporating sulfonic acid groups.

77. A power system as claimed in claim 61, wherein the individual anode and cathode electrodes are gas diffusing, and include an electrolyte, and wherein the electrolyte and the solid proton conducting membrane include a cross-linked copolymer having sulfonic acid groups.

78. A power system as claimed in claim 12, wherein each of the current collectors comprise:

a base substrate which is electrically conductive; and

an electrically conductive contact layer borne on the base substrate and which is galvanically cathodic and oxygen stable.

79. A power system as claimed in claim 78, and further comprising a protection layer which will passivate when exposed to oxygen;

and an electrolyte exclusion layer.

80. A power system as claimed in claim 78, wherein the base substrate is selected from group consisting essentially of chromium-containing stainless steel, copper, and nickel;

and the contact layer is selected from group comprising column IVB elements which form electrically conductive nitrides, and one or more coatings of palladium, platinum, rhodium, ruthenium, iridium, and osmium.

81. A power system as claimed in claim 79, wherein the protection layer is selected from the group consisting essentially of a foil cladding of chromium containing stainless steel and elements selected from column IVB of the periodic table and which form a highly passivated pentoxide when exposed to air.

82. A power system as claimed in claim 80, wherein the base substrate has a thickness of about 0.11 millimeters to about 3 millimeters;

and wherein the contact layer has a thickness of about 0.2 to about 20 microns.

83. A power system as claimed in claim 78, wherein the base substrate has a given surface area of which at least about 70% is open area.

84. A proton exchange membrane fuel cell power system comprising:

a plurality of discrete proton exchange membrane fuel cell modules each having a hydrogen distribution frame defining discrete, substantially opposed cavities;

a membrane electrode diffusion assembly which has opposite anode and cathode sides and which is sealably mounted in each of the cavities;

a pair of current collectors positioned in each of the cavities and individually oriented in juxtaposed ohmic electrical contact with the opposite anode and cathode sides of each of the membrane electrode diffusion assemblies;

a pressure transfer assembly positioned in each of the cavities and disposed in force transmitting relation relative to the membrane electrode diffusion assembly and the pair of current collectors; and

a cathode cover oriented in partially occluding relation relative to each of the cavities and matingly cooperating with the hydrogen distribution frame.

85. A power system as claimed in claim 84, and further comprising a biasing assembly oriented between the respective cathode covers and the pressure transfer assembly, and wherein the pressure transfer assembly applies a force of at least about 175 pounds per square inch which is realized between the membrane electrode diffusion assembly and the associated pair of current collectors.

86. A power system as claimed in claim 84, and further comprising a pressure distribution assembly which is positioned between the cathode cover and the pressure transfer assembly.

87. A power system as claimed in claim 84, wherein the hydrogen distribution frame further defines a first passageway which permits the delivery of hydrogen gas to each of the cavities and to the anode side of the membrane electrode diffusion assembly, and a second passageway which facilitates the removal of impurities, water and unreacted hydrogen from each of the cavities, and wherein each of the cathode covers and the respective pressure transfer assembly defines a third passageway which permits delivery of air to each of the cavities and to the cathode side of each of the respective membrane electrode diffusion assemblies.

88. A power system as claimed in claim 84, wherein the membrane electrode diffusion assemblies comprise:

a solid proton conducting electrolyte membrane which has opposite anode and cathode sides;

individual catalytic anode and cathode electrodes disposed in ionic contact with the respective anode and cathode sides of the electrolyte membrane; and

a diffusion layer borne on each of the anode and cathode electrodes and which is electrically conductive and has a minimum porosity.

89. A power system as claimed in claim 88, wherein the electrolyte membrane has at least about a 20% molar concentration of a sulfonic acid.

90. A power system as claimed in claim 88, wherein the electrolyte membrane comprises:

about 35% to about 50% by molar concentration of a methacrylate monomer;

about 30% to about 50% by molar concentration of an acrylate monomer;

about 25% to about 45% by molar concentration of a sulfonic acid monomer; and

about 5% to about 20% by molar concentration of a compatible crosslinking agent.

91. A power system as claimed in claim 84, wherein the individual current collectors comprise:

a base substrate having a bulk conductivity of at least about 13% IACS; and

a passivated oxide coating over the base substrate and which is inert and galvanically cathodic.

92. A power system as claimed in claim 91, wherein the base substrate has a surface area of which at least 70% is open area.

93. A power system as claimed in claim 84, wherein the cathode covers are fabricated from a substrate having a flexural modulus of at least about 1.00 million pounds per square inch, and wherein the hydrogen distribution frame is fabricated from a substrate having a flexural modulus of less than about 500,000 pounds per square inch, and a compressive strength of less than about 20,000 pounds per square inch.

94. A power system as claimed in claim 84, and further comprising:

a subrack for supporting the plurality of discrete fuel cell modules;

a plenum made integral with the subrack, the plenum having an exhaust end which delivers air to each of the fuel cell modules supported on the subrack, and an intake end which receives both air which has passed through each of the fuel cell modules, and air which comes from outside of the respective fuel cell modules;

an air movement assembly operably coupled to the plenum for moving the air along the plenum to the individual fuel cell modules; and

an air mixing valve borne by the plenum and controlling the amount of air which has passed through the respective fuel cells and which is recirculated back to each of the fuel cell modules.

95. A proton exchange membrane fuel cell power system comprising:

a plurality of discrete fuel cell modules each having a hydrogen distribution frame defining discrete, substantially opposed cavities, the hydrogen distribution frame defining a first passageway which permits the simultaneous delivery of hydrogen gas to each of the cavities, and a second passageway which facilitates the removal of impurities, water and unreacted hydrogen from each of the cavities;

a membrane electrode diffusion assembly which has opposite anode and cathode sides and which is sealably mounted in each of the cavities, the membrane electrode diffusion assembly having a solid proton conducting electrolyte membrane which has opposite anode and cathode sides;

individual catalytic anode and cathode electrodes disposed in ionic contact with the respective anode and cathode sides of the electrolyte membrane; and

a diffusion layer borne on each of the anode and cathode electrodes and which is electrically conductive and has a minimum pore size;

a pair of current collectors positioned in each of the cavities and individually oriented in juxtaposed ohmic electrical contact with the opposite anode and cathode sides of each of the membrane electrode diffusion assemblies, and wherein the current collectors have a surface coating which is inert and galvanically cathodic;

a pressure transfer assembly positioned in each of the cavities and disposed in force transmitting relation relative to the membrane electrode diffusion assembly and the pair of current collectors, and wherein the pressure transfer assembly has a main body with a plurality of resilient members extending therefrom;

a cathode cover oriented in partially occluding relation relative to each of the cavities and matingly cooperating with the hydrogen distribution frame, and wherein the cathode covers and the respective pressure transfer assembly define a third passageway which permits delivery of air to each of the cavities and to the cathode side of the membrane electrode diffusion assembly; and

a biasing assembly oriented between the respective cathode covers and the pressure transfer assembly, and wherein a force of at least about 175 pounds per square inch is realized between the membrane electrode diffusion assembly and the associated pair of current collectors.

96. A power system as claimed in claim 95, and further comprising:

a subrack for supporting the plurality of discrete fuel cell modules;

a plenum made integral with the subrack, the plenum having an exhaust end which delivers air to each of the fuel cell modules supported on the subrack, and an intake end which receives both air which has passed through each of the fuel cell modules, and air which comes from outside of the respective fuel cell modules;

an air movement assembly operably coupled to the plenum for moving the air in a given direction along the plenum to the individual fuel cell modules; and

an air mixing valve borne by the plenum and controlling the amount of air which has passed through the respective fuel cells and which is recirculated back to each of the fuel cell modules.

97. A power system as claimed in claim 95, wherein the cathode covers are fabricated from a substrate having a flexural modulus of at least about 1.00 million pounds per square inch, and wherein the hydrogen distribution frame is fabricated from a substrate having a flexural modulus of less than about 500,000 pounds per square inch, and a compressive strength of less than about 20,000 pounds per square inch.

98. A power system as claimed in claim 95, wherein the electrolyte membrane comprises:

at least about 10% to about 50% by molar concentration of a copolymer which has monomeric units which are selected from the group consisting essentially of poly (ethylene glycol) methacrylate, poly (propylene glycol) methacrylate, poly (ethylene glycol) ethyl ether methacrylate, poly (propylene glycol) methyl ether methacrylate, hydroxypropyl methacrylate, 2-hydroxyethyl methacrylate, acrylate analogs and 4-hydroxybutyl acrylate;

at least about 25% to about 45% by molar concentration of an acid selected from the group consisting essentially of 3-alkoxy-2-hydroxy-1-propanesulfonic acid, 4-styrenesulfonic acid, vinylsulfonic acid, 3-sulfopropyl methacrylate, 3-sulfopropylacrylate and fluorinated derivatives thereof;

at least about 5% to about 20% by molar concentration of a crosslinking agent selected from the group consisting essentially of ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, glycerol dimethacrylate, diallyloxyacetic acid, and allylmethacrylate;

a compatible plasticizer; and

a support matrix having a minimum porosity, and which is not electrically conductive.

99. A power system as claimed in claim 95, wherein the solid proton conducting electrolyte membrane comprises:

a polymethacrylate;

an acrylate or methacrylate;

a sulfonic acid;

a crosslinking agent; and

a compatible plastizer.

100. A power system as claimed in claim 95, wherein the current collectors comprise:

a base substrate having a bulk conductivity of at least about 2.4% IACS; and

a contact layer over the base substrate and which is electrically conductive, galvanically cathodic, and oxygen stable, and wherein the contact layer consists essentially of substances having constituent elements from Groups IVB of the periodic table of elements, and wherein the contact layer is further characterized by its ability to form an electrically conductive nitride.

101. A power system as claimed in claim 95, wherein the discrete fuel cell modules are self-humidifying, and wherein each of the membrane electrode diffusion assemblies has an active area which has a given surface area, and wherein each of the discrete fuel cell modules produces a current density of at least about 350 mA per square centimeter of active area at a nominal cell voltage of about 0.5 volts D.C., and wherein the plurality of discrete fuel cell modules each have an electrical output of at least about 10.5 watts.

102. A power system housing comprising:

an enclosure defining a cavity;

a subrack mounted in the cavity and supporting a plurality of discrete proton exchange membrane full cell modules in the cavity, and wherein the subrack has forward and rearward edges, and top and bottom portions, and wherein the power system housing further comprises an air distribution assembly which is received in the enclosure and coupled in fluid flowing relation relative to the top and bottom portions of the subrack, and wherein the subrack further includes a plenum made integral with each of the subracks, the plenum having an intake end which receives air from each of the discrete proton exchange membrane fuel cell modules supported on the subrack at the top and bottom portions thereof, and air which comes from outside of the respective proton exchange membrane fuel cell modules; and

an exhaust end which delivers both air which has passed through each of the proton exchange membrane fuel cell modules, and air which comes from outside of the respective proton exchange membrane fuel cell modules;

an air movement assembly operably coupled to the plenum for moving the air from the intake end to the exhaust end of the plenum; and

an air mixing valve operably coupled with the plenum and controlling the amount of air which has passed through the respective fuel cells and which is recirculated back to each of the fuel cell modules.

103. A power system housing as claimed in claim 102, wherein the discrete proton exchange membrane fuel cell modules produce thermal energy, and wherein the power system comprises a heat exchanger which is coupled in fluid flowing relation relative to the air distribution assembly, and which captures the thermal energy produced by each of the discrete fuel cell modules.

104. A power system housing as claimed in claim 102, wherein the air mixing valve is disposed in selectively adjustable fluid metering relation relative to the intake end of the plenum, and the air movement assembly is disposed intermediate the intake and exhaust ends of the plenum, and wherein the air mixing valve mixes both air which comes from outside of the respective discrete proton exchange membrane fuel cell modules and air which has passed through each of the discrete proton exchange membrane fuel cell modules.

105. A power system housing as claimed in claim 102, and further comprising:

temperature sensors for sensing the temperature of the air entering the discrete proton exchange membrane fuel cell modules, the outside air, and the air which has passed through each of the discrete proton exchange membrane fuel cell modules;

an actuator disposed in force transmitting relation relative to the air mixing valve, the actuator, when energized, moving the air mixing valve along a given course of travel between a first position and a second position, and wherein movement of the air mixing valve along the course of travel facilitates the selective mixing of the outside air with the air which has previously passed through the respective proton exchange membrane fuel cell modules; and

a controller electrically coupled in sensing relation relative to the temperature sensors and the actuator, the controller selectively energizing the actuator to move the air mixing valve along the course of travel to control the temperature of the air delivered at the exhaust end of the plenum.

106. A power system housing as claimed in claim 105, wherein the air mixing valve, when located in the first position delivers outside air to the plenum, and in the second position, the air mixing valve delivers a variable mixture of both air which comes from outside of the respective discrete proton exchange membrane fuel cell modules and air which has passed through each of the respective discrete proton exchange membrane fuel cell modules.

107. A power system housing as claimed in claim 105, wherein the air movement assembly has a speed of operation which is variably adjustable, and wherein the controller is electrically coupled in controlling relation relative to the speed of operation of the air movement assembly.

108. A power system housing as claimed in claim 102, wherein each of the discrete proton exchange membrane fuel cell modules produces electrical power, and wherein the power system housing further comprises a power conditioning assembly for receiving and inverting the electrical power produced by each of the discrete fuel cell modules.

109. A power system housing as claimed in claim 108, wherein the power conditioning assembly comprises:

an inverter for converting direct current voltage to alternating current voltage.

110. A power system housing as claimed in claim 102, wherein the discrete proton exchange membrane fuel cell modules produce thermal energy, and wherein the power system housing comprises a heat exchanger for capturing the thermal energy emitted by the discrete fuel cell modules.

111. A power system housing comprising:

an enclosure defining a cavity,

a subrack mounted in the cavity and supporting a plurality of discrete proton exchange membrane fuel cell modules; and

a digital programmable controller electrically coupled with each of the discrete proton exchange membrane fuel cell modules.

112. A power system housing comprising:

an enclosure defining a cavity;

a subrack mounted in the cavity and supporting a plurality of discrete proton exchange membrane fuel cell modules, and wherein the subrack has forward and rearward edges; and

a direct current bus mounted adjacent the rearward edge of the subrack, and the discrete proton exchange membrane fuel cell modules are releasably electrically coupled with the direct current bus.

113. A power system housing, comprising:

an enclosure defining a cavity;

a subrack mounted in the cavity, the subrack having forward and rearward edges, and top and bottom portions, the subrack supporting a plurality of discrete proton exchange membrane fuel cell modules in the cavity, and wherein the proton exchange fuel cell modules each produce thermal energy;

a hydrogen distribution assembly received in the cavity of the enclosure and mounted in fluid flowing relation relative to each of the discrete proton exchange membrane fuel cell modules; and

an air distribution assembly received in the enclosure and operably coupled with the subrack, the air distribution assembly delivering air to each of the proton exchange membrane fuel cell modules, and wherein the preponderance of the thermal energy is removed from the proton exchange membrane fuel cell modules by the air delivered bv the air distribution assembly.

114. A power system housing as claimed in claim 113, wherein each of the discrete proton exchange membrane fuel cell modules produces electrical power, and wherein the power system housing further comprises a power conditioning assembly for receiving and inverting the electrical power produced by each of the discrete fuel cell modules.

115. A power system housing as claimed in claim 114, wherein the power conditioning assembly comprises:

an inverter for converting direct current voltage to alternating current voltage.

116. A power system housing as claimed in claim 113, wherein the discrete proton exchange membrane fuel cell modules produce thermal energy, and wherein the power system housing comprises a heat exchanger for capturing the thermal energy emitted by the discrete fuel cell modules.

117. A power system housing comprising:

an enclosure defining a cavity;

a subrack mounted in the cavity and supporting a plurality of discrete proton exchange membrane fuel cell modules;

a hydrogen distribution assembly received in the cavity of the enclosure and mounted in fluid flowing relation relative to each of the discrete proton exchange membrane fuel cell modules;

an air distribution assembly received in the enclosure and operably coupled with the subrack, the air distribution assembly delivering air to each of the proton exchange membrane fuel cell modules; and

a digital programmable controller electrically coupled with each of the discrete proton exchange membrane fuel cell modules.

118. A power system housing comprising:

an enclosure defining a cavity;

a subrack having a rearward edge, and which is mounted in the cavity, and which supports a plurality of discrete proton exchange membrane fuel cell modules;

a hydrogen distribution assembly mounted in fluid flowing relation relative to each of the discrete proton exchange membrane fuel cell modules;

an air distribution assembly coupled to the subrack and delivering air to each of the proton exchange membrane fuel cell modules; and

a direct current bus mounted adjacent the rearward edge of the subrack, and wherein the discrete proton exchange membrane fuel cell modules are releasably electrically coupled with the direct current bus.

119. A power system housing comprising:

an enclosure defining a cavity;

a subrack mounted in the cavity, the subrack having forward and rearward edges, and top and bottom portions, the subrack supporting a plurality of discrete proton exchange membrane fuel cell modules in the cavity;

a hydrogen distribution assembly received in the cavity of the enclosure and mounted in fluid flowing relation relative to each of the discrete proton exchange membrane fuel cell modules;

an air distribution assembly comprising a plenum made integral with each of the subracks, the plenum having an exhaust end which delivers air to each of the proton exchange membrane fuel cell modules supported on the subrack at a location intermediate the top and bottom portions thereof, and an intake end which receives both air which has passed through each of the proton exchange membrane fuel cell modules and air which comes from outside of the respective proton exchange membrane fuel cell modules;

an air movement assembly operably coupled to the plenum for moving the air from the intake end to the exhaust end of the plenum; and

an air mixing valve operably coupled with the plenum and controlling the amount of air which has passed through the respective proton exchange membrane fuel cell modules and which is recirculated back to each of the proton exchange membrane fuel cell modules.

120. A power system housing as claimed in claim 119, wherein the air mixing valve is disposed in selectively adjustable fluid metering relation relative to the intake end of the plenum, and the air movement assembly is disposed intermediate the intake and exhaust ends of the plenum, and wherein the air mixing valve mixes both air which comes from outside of the respective discrete fuel cell modules and air which has passed through each of the discrete proton exchange membrane fuel cell modules.

121. A power system housing as claimed in claim 120, and further comprising:

temperature sensors for sensing the temperature of the air entering the discrete proton exchange membrane fuel cell modules, the outside air, and the air which has passed through each of the discrete proton exchange membrane fuel cell modules;

an actuator disposed in force transmitting relation relative to the air mixing valve, the actuator, when energized, moving the air mixing valve along a given course of travel between a first position and a second position, and wherein movement of the air mixing valve along the course of travel facilitates the selective mixing of the outside air with the air which has previously passed through the respective proton exchange membrane fuel cell modules; and

a controller electrically coupled in sensing relation relative to the temperature sensors and the actuator, the controller selectively energizing the actuator to move the air mixing valve along the course of travel to control the temperature of the air delivered to the exhaust end of the plenum.

122. A power system housing as claimed in claim 121, wherein the air mixing valve, when located in the first position, delivers outside air to the plenum, and in the second position, the air mixing valve delivers a variable mixture of both air which comes from outside the respective discrete proton exchange membrane fuel cell modules and air which has passed through each of the respective discrete proton exchange membrane fuel cell modules.

123. A power system housing as claimed in claim 121, wherein the air movement assembly has a speed of operation which is variably adjustable, and wherein the controller is electrically coupled in controlling relation relative to the air movement assembly to control the speed of operation of the air movement assembly.

124. A power system housing as claimed in claim 123 wherein the discrete proton exchange membrane fuel cell modules produce thermal energy, and wherein the power system housing comprises a heat exchanger which is coupled in fluid flowing relation relative to the air distribution assembly, and which captures the thermal energy produced by each of the discrete proton exchange membrane fuel cell modules.

125. A power system housing comprising:

an enclosure defining a cavity;

a subrack mounted in the cavity, the subrack having forward and rearward edges, and top and bottom portions, the subrack supporting a plurality of discrete proton exchange membrane fuel cell modules in the cavity, each of the proton exchange membrane fuel cell modules producing direct current voltage, and wherein the top and bottom portions of the subrack are connected in fluid flowing relation relative to each of the discrete proton exchange membrane fuel cell modules;

a hydrogen distribution assembly received in the cavity of the enclosure and mounted in fluid flowing relation relative to each of the discrete proton exchange membrane fuel cell modules, the hydrogen distribution assembly operably coupled to each of the discrete proton exchange membrane fuel cell modules at a location adjacent the rearward edge of the subrack;

an air distribution assembly received in the enclosure and coupled in fluid flowing relation relative to the top and bottom portions of the subrack, the air distribution assembly delivering air to each of the proton exchange membrane fuel cell modules, and wherein the air distribution assembly includes a plenum having an exhaust end which is positioned intermediate the top and bottom portions of the subrack and which delivers air to each of the discrete proton exchange membrane fuel cell modules, and an intake end connected at the top and bottom portions of the subrack and which receives both air which has passed through each proton exchange membrane fuel cell modules and air which comes from outside the respective proton exchange membrane fuel cell modules;

an air movement assembly operably coupled to the plenum for moving the air along the plenum to the individual proton exchange membrane fuel cell modules; and

an air mixing valve operably coupled with the plenum and controlling the amount of air which has passed through the respective proton exchange membrane fuel cell modules and which is delivered back to each of the proton exchange membrane fuel cell modules; and

an inverter electrically coupled with each of the proton exchange membrane fuel cell modules and converting the direct current voltage to alternating voltage.

126. A power system housing as claimed in claim 125, wherein the discrete proton exchange membrane fuel cell modules produce thermal energy, and wherein the power system housing comprises a heat exchanger for capturing the thermal energy emitted by the discrete fuel cell modules.

127. A power system housing as claimed in claim 125, and further comprising a digital programmable controller electrically coupled with each of the discrete proton exchange membrane fuel cell modules.

128. A power system housing as claimed in claim 125, and further comprising a direct current bus which is mounted adjacent the rearward edge of the subrack, and wherein the discrete proton exchange membrane fuel cells are releasably electrically coupled with the direct current bus.

129. A power system housing as claimed in claim 125, wherein the air mixing valve is disposed in selectively adjustable fluid metering relation relative to the intake end of the plenum, and the air movement assembly is disposed intermediate the intake and exhaust ends of the plenum, and wherein the air mixing valve mixes both air which comes from outside of the respective discrete fuel cell modules and air which has passed through each of the discrete proton exchange membrane fuel cell modules.

130. A power system housing as claimed in claim 129, and further comprising:

temperature sensors for sensing the temperature of the air entering the discrete proton exchange membrane fuel cell modules, the outside air, and the air which has passed through each of the discrete proton exchange membrane fuel cell modules;

an actuator disposed in force transmitting relation relative to the air mixing valve, the actuator, when energized, moving the air mixing valve along a given course of travel and between a first position, and a second position, and wherein movement of the air mixing valve along the course of travel facilitates the selective mixing of the outside air with the air which has previously passed through the respective proton exchange membrane fuel cell modules; and

a controller electrically coupled in sensing relation relative to the temperature sensors and the actuator, the controller selectively energizing the actuator to move the air mixing valve along the course of travel to control the temperature of the air delivered to the exhaust end of the plenum.

131. A power system housing as claimed in claim 130, wherein the air mixing valve, when located in the first closed position, delivers outside air to the plenum, and in the second position, the air mixing valve delivers a variable mixture of both air which comes from outside the respective discrete proton exchange membrane fuel cell modules, and air which has passed through each of the respective discrete proton exchange membrane fuel cell modules.

132. A power system housing as claimed in claim 130, wherein the air movement assembly has a speed of operation which is variably adjustable, and wherein the controller is electrically coupled in controlling relation relative to the air movement assembly to control the speed of operation of the air movement assembly.

133. A proton exchange membrane fuel cell module, comprising:

a hydrogen distribution frame defining a pair of discrete, substantially opposed cavities;

a membrane electrode diffusion assembly sealably mounted in each of the cavities which are defined by the hydrogen distribution frame, the membrane electrode diffusion assemblies each having opposite anode and cathode sides; and

a pair of current collectors each disposed in juxtaposed ohmic electrical contact with the opposite anode and cathode sides of each of the membrane electrode diffusion assemblies, and wherein the proton exchange membrane fuel cell module is self humidifying and produces heat energy, and wherein the proton exchange membrane fuel cell module has a cathode air flow, and a preponderance of the heat energy is removed from the proton exchange membrane fuel cell module by the cathode air flow.

134. A proton exchange membrane fuel cell module as claimed in claim 133, and further including a force application assembly which matingly cooperates with each of the cavities which are defined by the hydrogen distribution frame, the force application assembly comprising:

a cathode cover which partially occludes each of the respective cavities of the hydrogen distribution frame, the respective cathode covers individually releasably cooperating with each other and with the hydrogen distribution frame;

a pressure transfer assembly juxtaposed relative to the current collector which is disposed in ohmic electrical contact with cathode side of the membrane electrode diffusion assembly;

a pressure distribution assembly juxtaposed relative to the pressure transfer assembly; and

a biasing assembly oriented between the respective cathode covers and the pressure distribution assembly, and wherein the pressure transfer assembly applies a force of at least about 175 pounds per square inch which is realized between the membrane electrode diffusion assembly and the associated pair of current collectors.

135. A proton exchange membrane fuel cell module as claimed in claim 134, wherein the force distribution assembly further comprises:

a substantially non-compressible and deformable substrate; and

a compressible substrate mounted on the substantially non-compressible substrate and wherein the compressible substrate is in contact with the pressure transfer assembly.

136. A proton exchange membrane fuel cell module as claimed in claim 135, wherein the pressure distribution assembly facilitates the distribution of force from the adjoining cathode cover.

137. A proton exchange membrane fuel cell module as claimed in claim 134, wherein each cathode cover is fabricated from a substrate having a flexural modulus of at least about 1.00 million pounds per square inch, and wherein the hydrogen distribution frame is fabricated from a substrate having a flexural modulus of less than about 500,000 pounds per square inch, and a compressive strength of less than about 20,000 pounds per square inch.

138. A proton exchange membrane fuel cell module as claimed in claim 134, wherein the biasing assemblies comprise metal wave springs which matingly cooperate with the adjoining cathode cover and the pressure distribution assembly.

139. A proton exchange membrane fuel cell module as claimed in claim 134, wherein the hydrogen distribution frame further defines a first passageway which permits the delivery of a source of hydrogen gas to each of the cavities and to the anode side of the membrane electrode diffusion assembly, and a second passageway which facilitates the removal of impurities, water and unreacted hydrogen from each of the cavities, and wherein each of the cathode covers and the respective force application assemblies define a third passageway which permits the delivery of a source of air to each of the cavities and to the cathode side of each of the respective membrane electrode diffusion assemblies.

140. A proton exchange membrane fuel cell module as claimed in claim 139, wherein the pressure transfer assembly defines a given open area therebetween the adjacent current collector and the adjoining cathode cover, and wherein the open area defines, in part, the third passageway, and wherein the biasing assembly distributes the force transmitted by the respective cathode covers substantially uniformly over the second surface of each of the pressure plates.

141. A proton exchange membrane fuel cell module as claimed in claim 139, wherein the source of hydrogen gas is supplied by means of the first passageway to each of the cavities of the hydrogen distribution frame at a pressure of about 1 P.S.I.G. to about 10 P.S.I.G., and wherein the source of air is supplied at above ambient pressure.

142. A proton exchange membrane fuel cell module as claimed in claim 134, wherein the pressure transfer assembly comprises an elongated main body having opposite ends and top and bottom surfaces, and a plurality of resilient members extend from the main body from a position near the bottom surface thereof.

143. A proton exchange membrane fuel cell module as claimed in claim 133, wherein the membrane electrode diffusion assembly comprises:

a solid proton conducting electrolyte membrane which has opposite anode and cathode sides;

individual catalytic anode and cathode electrodes disposed in ionic contact with the respective anode and cathode sides of the electrolyte membrane; and

diffusion layer borne on each of the anode and cathode electrodes and which is electrically conductive and is porous.

144. A proton exchange membrane fuel cell module as claimed in claim 143, wherein the diffusion layer further comprises:

a first diffusion layer borne on the individual anode and cathode electrodes and which is positioned in ohmic electrical contact with each electrode and which is electrically conductive and has a pore size; and

a second diffusion layer borne on the first diffusion layer and which is positioned in ohmic electrical contact with the underlying first diffusion layer, and which further is electrically conductive and has a pore size which is greater than the pore size of the first diffusion layer.

145. A proton exchange membrane fuel cell module as claimed in claim 142, wherein the electrolyte membrane has at least about a 20% molar concentration of a sulfonic acid.

146. A proton exchange membrane fuel cell module as claimed in claim 143, wherein the electrolyte membrane comprises crosslinked polymeric chains incorporating sulfonic acid groups.

147. A proton exchange membrane fuel cell module comprising:

a hydrogen distribution frame defining a pair of cavities;

a membrane electrode diffusion assembly having opposite anode and cathode sides and which is sealably mounted on the hydrogen distribution frame and oriented in each of the cavities defined by the hydrogen distribution frame, the hydrogen distribution frame positioning the respective membrane electrode diffusion assemblies in substantially parallel spaced relation one to the other, and wherein the membrane electrode diffusion assembly comprises a solid proton conducting electrolyte membrane which has opposite anode and cathode sides;

individual catalytic anode and cathode electrodes disposed in ionic contact with the respective anode and cathode sides of the electrolyte membrane; and

a diffusion layer borne on each of the anode and cathode electrodes and which is electrically conductive and has a pore size;

a pair of current collectors each disposed in juxtaposed ohmic electrical contact with the opposite anode and cathode sides of each of the membrane electrode diffusion assemblies;

a pressure transfer assembly disposed in force transmitting relation relative to each membrane electrode diffusion assembly and associated pair of current collectors which are received in each of the cavities defined by the hydrogen distribution frame;

a cathode cover partially occluding each of the respective cavities of the hydrogen distribution frame, the cathode covers matingly cooperating with the hydrogen distribution frame and with the pressure transfer assembly; and

a biasing member disposed intermediate the cathode cover and the adjacent pressure transfer assembly.

148. A proton exchange membrane fuel cell module as claimed in claim 147, and further including a pressure distribution assembly which comprises:

a substantially non-compressible and flexible substrate; and

a compressible substrate mounted on the non-compressible substrate and which is juxtaposed relative to the pressure transfer assembly.

149. A proton exchange membrane fuel cell module as claimed in claim 148, wherein the non-compressible substrate is fabricated from a metal substrate;

and the compressible substrate is fabricated from a thermoplastic foam.

150. A proton exchange membrane fuel cell module as claimed in claim 149, wherein the biasing member comprises a plurality of metal wave springs which matingly cooperate with the adjoining cathode cover, and which forcibly engage the non-compressible substrate of the pressure distribution assembly.

151. A proton exchange membrane fuel cell module as claimed in claim 147, wherein each of the cathode covers are fabricated from a substrate having a flexural modulus of at least about 1.00 million pounds per square inch, and wherein the hydrogen distribution frame is fabricated from a substrate having a flexural modulus of less than about 500,000 pounds per square inch, and a compressive strength of less than about 20,000 pounds per square inch.

152. A proton exchange membrane fuel cell module as claimed in claim 147, wherein the hydrogen distribution frame further defines a first passageway which permits the delivery of a source of hydrogen gas to each of the cavities and to the anode side of the membrane electrode diffusion assembly, and a second passageway which facilitates the removal of impurities, water and unreacted hydrogen from each of the cavities, and wherein each of the cathode covers and the respective pressure transfer assembly define a third passageway which permits delivery of a source of air to each of the cavities and to the cathode side of each of the respective membrane electrode diffusion assemblies.

153. A proton exchange membrane fuel cell module as claimed in claim 152, wherein the pressure transfer assembly defines a given open area between the adjacent current collector and the adjoining cathode cover, and wherein the open area defines, in part, the third passageway, and wherein the biasing member cooperates with the pressure transfer assembly to distribute the force transmitted by the respective cathode covers to discrete locations on the adjoining current collector.

154. A proton exchange membrane fuel cell module as claimed in claim 152, wherein the source of hydrogen gas is supplied by means of the first passageway to each of the cavities of the hydrogen distribution frame at a pressure of about 1 P.S.I.G. to about 10 P.S.I.G., and wherein the source of air is supplied at above ambient pressure.

155. A proton exchange membrane fuel cell module as claimed in claim 147, wherein the pressure transfer assembly comprises an elongated main body;

and a plurality of deformable members extend therefrom.

156. A proton exchange membrane fuel cell module comprising:

a hydrogen distribution frame defining multiple pairs of discretely opposed cavities, the hydrogen distribution frame further defining first and second passageways, the first passageway facilitating the delivery of a source of hydrogen gas to each cavity, and the second passageway facilitating the removal of unreacted hydrogen gas, water and impurities from each of the cavities;

a membrane electrode diffusion assembly having opposite anode and cathode sides and which is sealably mounted on the hydrogen distribution frame and positioned in each of the cavities, the membrane electrode diffusion assembly having a solid proton conducting electrolyte membrane with opposite anode and cathode sides, and which has at least about a 20% molar concentration of sulfonic acid;

individual anode and cathode electrodes disposed in ionic contact with the respective anode and cathode sides of the electrolyte membrane; and

a diffusion layer borne on each of the anode and cathode electrodes;

a pair of current collectors individually disposed in juxtaposed ohmic electrical contact with the diffusion layer borne on each of the anode and cathode electrodes, the current collectors each having a base substrate which is electrically conductive; and

a contact layer over the base substrate, and wherein the individual current collectors have a given surface area of which at least about 70% is open area;

a pressure transfer assembly juxtaposed relative to the current collector which is oriented in ohmic electrical contact with the cathode side of the membrane electrode diffusion assembly, and wherein the pressure transfer assembly has an elongated main body having top and bottom surfaces, and a plurality of resilient members depend downwardly from the bottom surface thereof and forcibly engage the current collector which is disposed in ohmic electrical contact with the cathode side of the membrane electrode diffusion assembly, and wherein the pressure transfer assembly defines in part a third passageway which facilitates the delivery of a source of air to the cathode side of the membrane electrode diffusion assembly;

a cathode cover disposed in partially occluding relation relative to each of the cavities, and matingly cooperating with the pressure transfer assembly, the cathode cover, in part defining the third passageway, the individual cathode covers matingly engaging each other, and the hydrogen distribution frame; and

a biasing assembly positioned between the respective cathode covers, and the pressure transfer assembly, the biasing assembly transferring by means of the force transfer assembly substantially uniform force such that at least about 175 pounds per square inch is generated between each membrane electrode diffusion assembly and associated pair of current collectors.

157. A proton exchange membrane fuel cell power system comprising:

a proton exchange membrane fuel cell module which produces heat energy and which has a cathode air flow, and wherein the preponderance of the heat energy is removed by the cathode air flow.

158. A proton exchange membrane fuel cell comprising:

a fuel cell module having a pair of opposed cavities; and

a force application assembly received in each of the cavities of the proton exchange membrane fuel cell module.

159. A proton exchange membrane fuel cell power system comprising:

a proton exchange membrane fuel cell module;

a subrack supporting the proton exchange membrane fuel cell module;

a fuel distribution assembly coupled in fluid flowing relation relative to the subrack;

an air distribution assembly coupled in fluid flowing relation relative to the subrack; and

a D.C. bus releasably electrically coupled to the proton exchange membrane fuel cell module.

160. A proton exchange membrane fuel cell comprising:

a proton exchange membrane which comprises cross-linked polymeric chains incorporating sulfonic acid groups, and wherein the proton exchange membrane fuel cell has a cathode air flow, and produces heat energy, and wherein the preponderance of the heat energy produced by the proton exchange membrane fuel cell is removed by the cathode air flow.

161. A proton exchange membrane fuel cell module, comprising:

a hydrogen distribution frame defining a cavity;

a proton exchange membrane mounted in the cavity, the proton exchange membrane having opposite anode and cathode sides; and

individual current collectors disposed in ohmic electrical contact with the anode and cathode sides, and wherein the proton exchange membrane fuel cell module has a cathode air flow, and produces heat energy, and wherein the preponderance of the heat energy is removed from the proton exchange membrane fuel cell module by the cathode air flow.

162. A proton exchange membrane fuel cell comprising:

a module which receives a proton conducting electrolyte membrane which produces heat energy, and which has a cathode air flow, and wherein the preponderance of the heat energy is removed by the cathode air flow, and wherein the proton conducting electrolyte membrane further comprises;

about 35% to about 50%, by molar concentration, of a methacrylate moiety;

about 30% to about 50%, by molar concentration, of an acrylate moiety;

about 25% to about 45%, by molar concentration, of a sulfonic acid moiety; and

about 5% to about 20% by molar concentration of a compatible crosslinking agent.