초록 ▼

A fuel cell having good resistance to compressive creep includes electrodes having a superstructure of porous electrically conductive foam with surface sections adjacent to opposing surfaces of an electrolyte matrix impregnated with electrode catalyst materials. The catalyst materials are affixed in

A fuel cell having good resistance to compressive creep includes electrodes having a superstructure of porous electrically conductive foam with surface sections adjacent to opposing surfaces of an electrolyte matrix impregnated with electrode catalyst materials. The catalyst materials are affixed in sections contiguous to an inner major surface by sinter bonding, electrochemical bonding or restrictive interstitial spacing. The outer sections of the porous plaque thickness are reserved for gas distribution to the electrode catalyst. Oxidant and fuel gases can be separately manifolded into alternate sides of a fuel cell stack by sealing opposing edges of the porous plaques containing the anode material in one set of opposing side surfaces and sealing opposing edges of the porous plaque containing cathode material in alternate side surfaces of the stack.

대표청구항 ▼

1. An electrode for a molten carbonate fuel cell comprising: a generally incompressible porous plaque having interconnecting porosity for gas passage throughout the length and breadth thereof, and; a coherent layer of particulate, electrochemically active catalyst material impregnated and sinter

1. An electrode for a molten carbonate fuel cell comprising: a generally incompressible porous plaque having interconnecting porosity for gas passage throughout the length and breadth thereof, and; a coherent layer of particulate, electrochemically active catalyst material impregnated and sinter bonded into only one surface section of said plaque thickness leaving a major fraction of said plaque thickness open for gas flow into contact with said coherent layer, said porous plaque extending through the thickness of said coherent layer to restrain compressive creep. 2. The electrode of claim 1 wherein a sheet of electrically conductive, gas impermeable material is bonded to a major surface opposite to said impregnated surface section to define a channel for gas flow into contact with the catalyst material of said coherent layer. 3. The electrode of claim 1 wherein said porous plaque exhibits general incompressibility by compressing less than 1% in thickness under 90-400 kPa pressure, for 100-500 hours at temperatures of 650° C. to 700° C. 4. The electrode of claim 1 wherein said porous plaque comprises an electrically conductive metal foam of about 60-99% porosity with a pore size distribution of about 100 to 300 microns. 5. The electrode of claim 4 wherein said porous plaque is an electrochemically formed skeleton of nickel chromium alloy. 6. The electrode of claim 1 wherein said porous plaque includes interstitial passages throughout its length and breadth and wherein said coherent layer of catalyst material includes sinter bonded particles within the interstitial passageways of the porous plaque at said one surface section. 7. The electrode of claim 1 wherein said coherent layer includes electrochemically deposited material within the interconnecting porosity of said porous plaque. 8. The electrode of claim 1 wherein said coherent layer includes catalytic materials selected from the group consisting of Ni, NiO, lanthium containing oxygenates, lithium containing oxygenates, zirconates and ferrates. 9. The electrode of claim 1 wherein said porous plaque includes a first thickness of first pore size for receiving particulate catalytic material and a second thickness of smaller pore size for restricting entry of catalytic material while permitting reactant gas distribution to the catalytic material. 10. The electrode of claim 1 wherein a first pair of opposing edge surfaces are sealed against reactant gas passage and a second pair of opposing edge surfaces are open to permit reactant gas passage, said first opposing pair are aligned generally perpendicular to the second opposing pair. 11. A fuel cell including a first electrode having a first catalyst for electrolytic reaction of fuel gas and means for admitting fuel gas into contact with said first catalyst, a second electrode having a second catalyst for electrolytic reaction of oxidant gas and means for admitting oxidant gas into contact with said catalyst and a porous matrix containing a molten carbonate electrolyte capable of ionic conduction between said first and said second electrodes wherein at least one of said electrodes comprises a porous plaque of generally incompressible electrically conductive material having a coherent layer of one of said catalysts embedded into only one major surface section of the plaque thickness leaving a major fraction of said plaque thickness with open interconnecting intersticies throughout for passage of reactant gas into contact with said catalyst, said porous plaque extending through the thickness of said one catalyst layer to said molten carbonate electrolyte-containing matrix. 12. The fuel cell of claim 11 wherein said first and second electrodes each comprise a porous plaque of generally incompressible electrically conductive material, each with a major surface section containing embedded catalysts disposed at opposite surfaces of and facing said porous electrolyte matrix. 13. The fuel cell of claim 12 wherein said porous plaques of both said first and second electrodes having sealed edge surfaces at two generally opposing edges and two open edge surfaces at two generally opposing edges, the open edges are generally perpendicular to the sealed edges and wherein a plurality of said first electrodes, the porous matrices and the second electrodes are assembled into a stack of fuel cells with the sealed edges of said first electrodes in alignment with the open edges of said second electrodes and the open edges of said first electrode in alignment with the sealed edges of said first electrode for coupling to separate supply and discharge manifolds of fuel and oxidant gases and wherein each of said electrodes having a gas impermeable sheet bonded to the major surface of said porous plaque opposite to the surface section containing said catalyst. 14. The fuel cell stack of claim 13 including porous plaques that exhibit a compressibility of less than 1% in height after about 500 hours duration, 100-400 kPa load and 650°-700° C. temperature. 15. The fuel cell of claim 11 wherein the one catalyst is embedded particulate material in said one major surface section. 16. The fuel cell of claim 11 wherein said one catalyst is electrochemically deposited material in said one major surface section and wherein there is included electrochemically deposited reforming catalyst in said porous plaque. 17. A method of preparing an electrode component for a fuel cell comprising: providing a generally incompressible porous plaque of electrically conductive material having interconnecting interstices throughout; impregnating a section contiguous to only one major surface with a catalyst having electrochemical activity while leaving an adjacent section contiguous to the opposite major surface unfilled to permit passage of reactant gas through said porous plaque; sealing opposing edges of said porous plaque to bar reactant gas entry or discharge while leaving alternate opposing edges open to admit and discharge reactant gases, and; affixing a gas impermeable sheet to the major surface opposite to said impregnated surface section of said porous plaque. 18. The method of claim 17 wherein particles of solid electrochemical catalyst are blended with a polymeric binder into a paste, the paste is formed into a sheet and pressed into a section of said porous plaque contiguous with only one major surface thereof. 19. The method of claim 18 wherein said particles of electrochemical catalyst are sinter bonded together within intersticies of said porous plaque while driving off said polymeric binder. 20. The method of claim 17 wherein said catalyst is electrochemically deposited into said porous plaque and wherein a gas impermeable sheet is bonded to the major surface opposite to said impregnated surface section and additional gas impermeable sheet sections are bonded to the opposing edges of said porous plaque.