Certain monomer composition mixtures having desirable properties for purposes of impregnating porous substrates (e.g. low viscosity, low vapor pressure, low viscosity) have also been found after curing to have surprisingly good mechanical characteristics at elevated temperature (e.g. relatively high storage modulus and flexural stress at 90 C.). These monomer compositions comprise a blend of at least two different monomers, the first being a mono- or difunctional methacrylic or acrylic ester and the second being a polyfunctional methacrylic or acrylic ester. The total amount of monofunctional and difunctional monomers in the composition is in a weight range from about 20 to about 90% and the total amount of polyfunctional monomers is in a weight range from about 10 to about 80%. These monomer compositions are particularly suitable for preparing robust, impregnated carbon plates for use in solid polymer electrolyte fuel cells, which typically operate around this elevated temperature.

Certain monomer composition mixtures having desirable properties for purposes of impregnating porous substrates (e.g. low viscosity, low vapor pressure, low viscosity) have also been found after curing to have surprisingly good mechanical characteristics at elevated temperature (e.g. relatively high storage modulus and flexural stress at 90 C.). These monomer compositions comprise a blend of at least two different monomers, the first being a mono- or difunctional methacrylic or acrylic ester and the second being a polyfunctional methacrylic or acrylic ester. The total amount of monofunctional and difunctional monomers in the composition is in a weight range from about 20 to about 90% and the total amount of polyfunctional monomers is in a weight range from about 10 to about 80%. These monomer compositions are particularly suitable for preparing robust, impregnated carbon plates for use in solid polymer electrolyte fuel cells, which typically operate around this elevated temperature.

Composite members, a fuel cell and manufacturing method, where the composite members are mounted on a base and comprise a first insulator and a second insulator layered on either side of an interconnector, exposed in a chamfered portion on opposite corners. Between a pair of the composite members is formed an electrolyte film. An anode is formed so as to cover the anode surface of the electrolyte film and an anode-side protrusion. The anode formed at the top of anode-side protrusion is stripped, forming a flat exposed surface on the top of the anode-side protrusion. A cathode is formed so as to cover the cathode surface of the electrolyte film and a cathode-side protrusion. The cathode formed on the top of the cathode-side protrusion is stripped using a spatula, a blade, etc., forming a flat exposed surface on the top of the cathode-side protrusion.

A membrane electrode assembly and fuel cell having such assembly. The membrane electrode assembly has a polymer electrolyte membrane, two catalytic electrodes in contact with the polymer electrolyte membrane on both sides, namely an anode and a cathode, and two gas diffusion layers directly or indirectly adjoining the electrodes, namely an anode-side gas diffusion layer and a cathode-side gas diffusion layer. At least one of the gas diffusion layers may optionally feature a microporous layer facing the polymer electrolyte membrane. The sequence of layers is anode-side gas diffusion layer, anode-side microporous layer, anode, polymer electrolyte membrane, cathode, cathode-side microporous layer, cathode-side gas diffusion layer. A relative hydrophobicity of at least two of these components and/or a hydrophobicity gradient within at least one of these components, and a relative pore structure having pore size and/or porosity of at least two of these components and/or a gradient within the pore structure of at least one of these components, is designed in such a way that it promotes the transport of water via the polymer electrolyte membrane, preferably from the cathode side to the anode side.

A membrane electrode assembly and fuel cell having such assembly. The membrane electrode assembly has a polymer electrolyte membrane, two catalytic electrodes in contact with the polymer electrolyte membrane on both sides, namely an anode and a cathode, and two gas diffusion layers directly or indirectly adjoining the electrodes, namely an anode-side gas diffusion layer and a cathode-side gas diffusion layer. At least one of the gas diffusion layers may optionally feature a microporous layer facing the polymer electrolyte membrane. The sequence of layers is anode-side gas diffusion layer, anode-side microporous layer, anode, polymer electrolyte membrane, cathode, cathode-side microporous layer, cathode-side gas diffusion layer. A relative hydrophobicity of at least two of these components and/or a hydrophobicity gradient within at least one of these components, and a relative pore structure having pore size and/or porosity of at least two of these components and/or a gradient within the pore structure of at least one of these components, is designed in such a way that it promotes the transport of water via the polymer electrolyte membrane, preferably from the cathode side to the anode side.

This redox flow secondary battery has an electrolyte tank (6) containing: a positive electrode cell chamber (2) containing a positive electrode (1) comprising a carbon electrode; a negative electrode cell chamber (4) containing a negative electrode (3) comprising a carbon electrode; and an electrolyte membrane (5) as a barrier membrane that separates/isolates the positive electrode cell chamber (2) and the negative electrode cell chamber (4). The positive electrode cell chamber (2) contains a positive electrode electrolyte containing an active substance, the negative electrode cell chamber (4) contains a negative electrode electrolyte containing an active substance, and the redox flow secondary battery charges and discharges on the basis of the change in valency of the active substances in the electrolytes. The electrolyte membrane (5) contains an ion exchange resin composition that is primarily a polyelectrolyte polymer, and the electrolyte membrane (5) has a reinforcing material comprising a fluorine-based porous membrane.

This redox flow secondary battery has an electrolyte tank (6) containing: a positive electrode cell chamber (2) containing a positive electrode (1) comprising a carbon electrode; a negative electrode cell chamber (4) containing a negative electrode (3) comprising a carbon electrode; and an electrolyte membrane (5) as a barrier membrane that separates/isolates the positive electrode cell chamber (2) and the negative electrode cell chamber (4). The positive electrode cell chamber (2) contains a positive electrode electrolyte containing an active substance, the negative electrode cell chamber (4) contains a negative electrode electrolyte containing an active substance, and the redox flow secondary battery charges and discharges on the basis of the change in valency of the active substances in the electrolytes. The electrolyte membrane (5) contains an ion exchange resin composition that is primarily a polyelectrolyte polymer, and the electrolyte membrane (5) has a reinforcing material comprising a fluorine-based porous membrane.

A solid oxide fuel cell having a plurality of planar layered fuel cell units, an electrically conductive flow separator plate disposed between each of the fuel cell units, and a cathode contact material element disposed between each cathode electrode of the fuel cell units and each electrically conductive flow separator plate. The cathodes of the individual fuel cell units are modified such that the operating temperatures of the cathodes are matched with the temperatures they experience based upon their locations in the fuel cell stack. The modification involves adding to the cathode contact material and/or cathode at least one alloying agent which modifies the temperature of the cathode electrodes based upon the location of the cathode electrodes within the fuel cell stack. These alloying agents react with a component of the cathode electrode to form alloys.

A system for fuel cell membrane edge protection includes a fuel cell including a fuel-cell membrane-subgasket assembly. The assembly includes an anode gas diffusion electrode and a cathode gas diffusion electrode configured for facilitating an electrochemical reaction. The reaction creates water as a by-product. The assembly further includes a proton exchange membrane disposed between the electrodes and a subgasket. The subgasket includes an interior aperture portion defined by a perimeter and is connected to the anode gas diffusion electrode and the membrane about the perimeter such that an area of overlap between the subgasket, the electrode, and the membrane exists around the perimeter. The assembly further includes a carbon paper layer spanning the interior aperture portion. The layer includes patterned wettability and is configured to move the water away from the area of overlap into a center portion of the layer.

A system for fuel cell membrane edge protection includes a fuel cell including a fuel-cell membrane-subgasket assembly. The assembly includes an anode gas diffusion electrode and a cathode gas diffusion electrode configured for facilitating an electrochemical reaction. The reaction creates water as a by-product. The assembly further includes a proton exchange membrane disposed between the electrodes and a subgasket. The subgasket includes an interior aperture portion defined by a perimeter and is connected to the anode gas diffusion electrode and the membrane about the perimeter such that an area of overlap between the subgasket, the electrode, and the membrane exists around the perimeter. The assembly further includes a carbon paper layer spanning the interior aperture portion. The layer includes patterned wettability and is configured to move the water away from the area of overlap into a center portion of the layer.