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An electrochemical fuel cell contains first and second monolithic electrically conducting flow field-bipolar plate assemblies arranged essentially parallel to each other such that an inside surface of the first bipolar separator plate is facing an inside surface of the second bipolar separator plate

An electrochemical fuel cell contains first and second monolithic electrically conducting flow field-bipolar plate assemblies arranged essentially parallel to each other such that an inside surface of the first bipolar separator plate is facing an inside surface of the second bipolar separator plate, wherein the bipolar separator plates are electrically and mechanically connected by intervening layers that are directly bonded to each other. The fuel cells can be stacked between endplates and supplied with hydrogen and oxygen to generate electric power. An air cooled condenser for use with a fuel cell stack is composed of a porous foam condensing element and a porous foam cooling element. The condenser can be placed by a fuel cell stack for cooling purposes.

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1. An electrochemical fuel cell comprising first and second monolithic electrically conducting flow field-bipolar plate assemblies arranged essentially parallel to each other such that an inside surface of the first flow field-bipolar plate assembly is facing an inside surface of the second flow fie

1. An electrochemical fuel cell comprising first and second monolithic electrically conducting flow field-bipolar plate assemblies arranged essentially parallel to each other such that an inside surface of the first flow field-bipolar plate assembly is facing an inside surface of the second flow field-bipolar plate assembly, wherein the flow field-bipolar plate assemblies are electrically and mechanically connected by intervening layers, the intervening layers comprising:a first electrically conducting intermediate layer bonded directly to the inside surface of the first flow field-bipolar plate assembly,a second electrically conducting imtermediate layer bonded directly to the inside surface of the second flow field-bipolar plate assembly,a first electrode bonded directly to the inside surface of the first electrically conducting intermediate layer,second electrode bonded directly to the inside surface of the second electrically conducting intermediate layer, anda polymer electrolyte membrane between and bonded directly to both of the electrodes wherein the monolithic flow field-bipolar plate assemblies comprise a first and second porous metal flow field directly bonded to opposite sides of an electrically conducting gas barrier by continuous metallurgical bonds and wherein the porous metal flow fields are configured to deliver gaseous reactants to the intermediate layers by flowing through the pores of the porous metal flow fields. 2. The electrochemical fuel cell of claim 1, wherein the porous metal flow fields are directly bonded to the electrically conducting gas barrier by electroplating or sintering. 3. The electrochemical fuel cell of claim 1, wherein the electrically conducting gas barrier comprises a metal foil. 4. The electrochemical fuel cell of claim 1, wherein at least one porous metal flow field comprises a three-dimensional reticulated metal structure. 5. The electrochemical fuel cell of claim 1, wherein at least one porous metal flow field further comprises a protecting layer disposed on at least one surface thereof. 6. The electrochemical fuel cell of claim 5, wherein the protecting layer comprises a metal or a metal oxide. 7. The electrochemical fuel cell of claim 6, wherein the protecting layer is a continuous layer of tin oxide. 8. The electrochemical fuel cell of claim 1, wherein the intermediate layer comprises a polymer and high surface area carbon particles. 9. The electrochemical fuel cell of claim 8, wherein the polymer comprises polytetrafluoroethylene, perfluoroethylene-perfluropropylene copolymer, perfluoro-alkoxy, or polyvanilidene fluoride. 10. The electrochemical fuel cell of claim 1, wherein the electrode comprises a polymer electrolyte and an electrocatalyst. 11. The electrochemical fuel cell of claim 1, wherein at least one of the flow field-bipolar plate assemblies comprises a first metal flow field directly bonded to the outside surface of an electrically conducting gas impermeable barrier, a second porous metal flow field directly bonded to the outside surface of a second electrically conducting gas impermeable barrier, and a porus metal cooling field disposed between and directly bonded to the inside surfaces of the first and second gas impermeable barriers. 12. An electrochemical fuel cell stack comprising two electrically conducting end-plates and a plurality of electrochemical fuel cells disposed between the endplates, wherein the electrochemical fuel cells comprise first and second monolithic electrically conducting flow field-bipolar plate assemblies arranged essentially parallel to each other such that an inside surface of the first flow field-bipolar plate assembly is facing an inside surface of the second flow field-bipolar plate assembly, wherein the flow field-bipolar plate assemblies are electrically and mechanically connected by intervening layers, the intervening layers comprising:a first electrically conducting intermediate layer bonded directly to the inside surface of th e first flow field-bipolar plate assembly,a second electrically conducting intermediate layer bonded directly to the inside surface of the second flow field-bipolar plate assembly,a first electrode bonded directly to the inside surface of the first electrically conducting intermediate layer,a second electrode bonded directly to the inside surface of the second electrically conducting intermediate layer, anda polymer electrolyte membrane between and bonded directly to both of the electrodes wherein the monolithic flow field-bipolar plate assemblies comprise a first and second porous metal flow field directly bonded to opposite sides of an electrically conducting gas barrier by continuous metallurgical bonds and wherein the porous metal flow fields and configured to deliver gasesous reactants to the intermediate layers by flowing through the pores of the porous metal flow fields. 13. A method of making a fuel cell stack comprising disposing between two electrically conducting endplates a plurality of electrochemical fuel cells, wherein the electrochemical fuel cells comprise first and second monolithic electrically conducting flow field-bipolar plate assemblies arranged essentially parallel to each other such that an inside surface of the first flow field-bipolar plate assembly is facing an inside surface of the second flow field-bipolar plate assembly, wherein the flow field-bipolar plate assemblies are electrically and mechanically connected by intervening layers, the intervening layers comprising:a first electrically conducting intermediate layer bonded directly to the inside surface of the first flow field-bipolar plate assembly,a second electrically conducting intermediate layer bonded directly to the inside surface of the second flow field-bipolar plate assembly,a first electrode bonded directly to the inside surface of the first electrically conducting intermediate layer,a second electrode bonded directly to the inside surface of the second electrically conducting intermediate layer, anda polymer electrolyte membrane disposed between and bonded directly to both of the electodes wherein the monolithic flow field-bipolar plate assemblies comprises a first and second porous metal flow field directly bonded to opposite sides of an electrically conducting gas barrier by continuous metallurgial bonds and wherein the porous metal flow fields are configured to deliver gaseous reactants to the intermediate layers by flowing through the pores of the porous metal flow fields. 14. A method of generating electrical power comprising supplying hydrogen and oxygen to an electrochemical fuel cell stack,wherein the electrochemical fuel cell stack comprises two electrically conducting end-plates and plurality of electrochemical fuel cells disposed between the endplates; wherein the electrochemical fuel cells comprise first and second monolithic electrical conducting flow field-biopolar plate assemblies arranged essentially parallel to each other such that an inside surface of the first flow field-bipolar plate assembly is facing an inside surface of the second flow field-bipolar plate assembly, wherein the flow field-bipolar assemblies are electrically and mechanically connected by intervening layers, the intervening layers comprising:a first electrically conducting intermediate layer bonded directly to the inside surface of the first flow field-bipolar plate assembly,a second electrically conducting intermediate layer bonded directly to the inside surface of the second flow field-bipolar plate assembly,a first electrode bonded directly to the inside surface of the first electrically conducting intermediate layer,a second electrode bonded directly to the inside surface of the second electrically conducting intermediate layer, anda polymer electrolyte membrane between and bonded directly to both of the electrodes wherein the monolithic flow field-bipolar plate assemblies comprise a first and second porous metal flow field directly bonded to opposite sides of an electrically conducting gas barrier by continuous metallurgical bonds and wherein the porous metal flow fields are configured to deliver gaseous reactants to the intermediate layers by flowing through the porous metal flow fields.