Abstract: Spaced based burst power fuel cells generate large thermal loads in very short time periods. In order to avoid external venting or the use of heavy radiators in space vehicles, such fuel cells must include onboard closed-loop cooling systems. Utilizing multiple heat sinks containing subcooled ice as a cooling medium, sequentially contactable with a coolant that passes through the fuel cell, provides a safe, highly efficient and low weight heat absorption capability.

Abstract: A seal structure 60 for a porous plate of an electrochemical cell, such as plates 18, 20, includes a sealing material disposed in a seal region 66 of the plate to form a hydrophilic barrier to gas with an electrolyte and a hydrophobic layer 62 to block the loss of electrolyte from the hydrophilic layer is disclosed. Various construction details including a method for making the plate are disclosed which increase the cross pressure the sealing region of the plate can withstand. In one embodiment, the seal region 66 is impregnated with powder having a low structure and predetermined particle size using a pressurized liquid carrier. A FEP Teflon film bonds adjacent electrolyte reservoir plates together.

Abstract: The fuel cell system is adapted to be able to operate with oxygen-contaminated hydrogen-rich fuel gases without experiencing undesirably high temperature hot spots on the fuel cell electrodes. Oxygen in the fuel gas is catalytically burned in areas of the electrodes where no electrochemical reaction occurs. The oxygen content of the fuel gases is thus reduced to an acceptable level before the fuel gases flow over the portions of the electrodes which are electrochemically active. Anode exhaust can also be partially recirculated into the anode inlet to mix with incoming fuel gas thereby preliminarily diluting the amount of oxygen in the incoming fuel gases.

Abstract: A gaseous mixture of hydrogen and carbon dioxide is used as the fuel cell fuel or anode gas, and air is used as the oxidant or cathode gas in a nonalkaline fuel cell power plant. In feeding the fuel gas through the anode side of the fuel cell, hydrogen is removed during the electrochemical reaction and the fuel gas which is exhausted from the anode side has a much higher proportion of carbon dioxide to hydrogen than the entering fuel gas. The fuel gas exhaust is fed through a carbon dioxide absorber to remove carbon dioxide from the fuel exhaust. The carbon dioxide is recovered from the absorber for useful purposes and the hydrogen gas leaving the absorber is dewatered and burned in a reformer. Carbon dioxide emissions from the power plant are thus greatly reduced benefiting the environment.

Abstract: Molten carbonate fuel cell cathodes formed from a composition comprising oxides of nickel, lithium salts and barium salts having improved strength. These cathodes are fabricated by prefiring oxides of nickel and optionally lithium salts. The prefired powder is optionally leached with an organic acid and optional barium salts may be added. These powders are formed into an electrode and sintered. The resulting electrodes have improved strength.

Abstract: A matrix for holding the electrolyte within a phosphoric acid fuel cell is made from silicon carbide and a binder of polyestersulfone. Preferably the matrix consists of 10-20 weight percent polyethersulfone with a balance of silicon carbide. The matrix has improved strength, wettability and bubble pressure compared to the best known prior art matrix.

Abstract: Anodes having NiCo.sub.2 O.sub.4 catalyst used in the electrohydrodimerization of acrylonitrile to adiponitrile result in anode voltage requirements of less than about 2000 millivolts at 100 milliamperes per square centimeter of anode area. Typically, oxygen evolving anodes comprised of lead or carbon steel are utilized in the hydrodimerization of acrylonitrile to adiponitrile resulting in high voltage requirements. Anodes containing NiCo.sub.2 O.sub.4 catalyst require substantially reduced voltages and perform well in the conventional electrochemical adiponitrile production environment.

Abstract: Gas depolarized anodes used in the electrohydrodimerization of acrylonitrile to adiponitrile result in anode voltage requirements of less than about 400 millivolts at 100 milliamperes per square centimeter of electrode area. Typically, oxygen evolving anodes characterized by high theoretical voltages and high overvoltages are utilized in the hydrodimerization of acrylonitrile to adiponitrile. Gas depolarized anodes requiring substantially reduced voltages perform well in the conventional electrochemical adiponitrile production environment.

Abstract: A catalytic combustor particularly adapted for use in wood and coal burning stoves is described comprising a high temperature stable support material containing a high activity, sulfur tolerant combustion catalyst. In addition to having a relatively long life, the catalytic combustors according to the present invention demonstrate useful performance even in the presence of sulfur containing fuels. Furthermore, the catalytic combustors of the present invention improve the efficiency of such stoves over and above that provided by conventional catalytic combustors.

Abstract: A seal material especially adapted for phosphoric acid fuel cell stack sealing is described comprising an unfilled, unoiled high molecular weight polytetrafluoroethylene. Although the seal material is especially adapted as the regular seal around the plenums separating the oxygen and hydrogen gas inlets and outlets, it can also be used as a plenum or stack crack sealer. The material provides seal integrity and stability at temperatures in excess of 400.degree. F. (204.degree. C.)., e.g. 400.degree. F. to 450.degree. F. (204.degree. C. to 232.degree. C.), in a corrosive chemical environment at differential pressures above 50 psi (e.g. 50 psi to 80 psi). It can be used in electrochemical cells in general where high temperature, high pressure, corrosive environments prevail.

Abstract: A molten carbonate fuel cell ceria anode and a molten carbonate fuel cell including such anode are described. The ceria anode, in addition to having the requisite electrolyte compatibility, catalytic activity, and electron conductivity, has improved oxidation resistance and structural stability as well.

Abstract: A molten carbonate fuel cell electrolyte-matrix material and a molten carbonate fuel cell including such material are described. The electrolyte-matrix material comprises carbonate electrolytes in intimate combination with ceria matrix material. The electrolyte-matrix material shows substantially no phase change or reaction with the electrolyte after at least 2000 hours under molten carbonate fuel cell operating conditions.

Abstract: A molten carbonate fuel cell anode-matrix composite and a molten carbonate fuel cell including such composite are described. The anode-matrix material comprises carbonate electrolyte in intimate combination with ceria anode-matrix material. The anode-matrix material shows substantially no phase change or reaction with the electrolyte after at least 2000 hours under molten carbonate fuel cell operating conditions.

Abstract: A new type of electrochemical cell which can be used for generating electricity or in an electrolysis mode for producing gases such as hydrogen and oxygen comprises laterally spaced apart or side-by-side catalyst layers as electrodes with the gap between the catalyst layers being bridged by a solid electrolyte which provides an ion conductive path from one catalyst layer to the other. The catalyst layers and the electrolyte are preferably in the form of thin films or layers on the surface of an inert supporting substrate. A plurality of these cells may be disposed on the substrate and interconnected electrically forming a network of series and parallel connected cells. Means are provided to feed fuel and oxidant to the electrodes either as separate gases or mixed together if appropriate catalytic materials are selected.

Abstract: A thermally conductive caulk particularly suited for use in a phosphoric acid fuel cell is made by mixing graphite into a stable aqueous dispersion of polytetrafluoroethylene and fluorinated ethylene propylene such that the solids floc to form a paste. The paste is applied to the part to be caulked and then dried and heat treated. Caulks made according to the present invention have good thermal conductivity and absorb very little phosphoric acid.

Abstract: A matrix for retaining the electrolyte in a fuel cell is applied to the surface of one or both of the electrodes by screen printing using an inking vehicle which is an aqueous solution of polyethylene oxide. This method produces a very thin, continuous and uniform matrix layer and is well suited to production operations.

Abstract: A matrix for retaining the electrolyte in a fuel cell is applied to the surface of one or both of the electrodes by screen printing. In a preferred embodiment an aqueous solution of glycol is used as the inking vehicle to screen print a very thin, continuous and uniform matrix layer on the surface of an electrode.

Abstract: The internal coolant system of a fuel cell power plant utilizes a gas in the coolant fluid to inhibit the corrosion of those fuel cell components that corrode due to shunt currents flowing through the coolant fluid. In a preferred embodiment hydrogen gas is used.