Abstract: A catalyst ink composition for a fuel cell electrode is provided. The catalyst ink composition includes a plurality of electrically conductive support particles; a catalyst formed from a finely divided precious metal, the catalyst supported by the conductive support particles; an ionomer; at least one solvent; and a reinforcing material configured to bridge and distribute stresses across the electrically conductive support particles of the ink composition upon a drying thereof. An electrode for a fuel cell and a method of fabricating the electrode with the catalyst ink composition are also provided.

Abstract: A diffusion media and micro-porous media combination for a fuel cell. A diffusion layer is composed of a diffusion media and has a first (electrode) side and an opposite second (flowfield) side, wherein at least one of the first and second sides has a geometric pattern formed therein comprising a multiplicity of mutually spaced apart regions. A micro-porous media fills the multiplicity of regions and a micro-porous layer composed of the micro-porous media is continuously applied to the first surface.

Abstract: A gas diffusion layer for a fuel cell is described. The gas diffusion layer includes a carbon fiber mat having a substantially open structure. Bloomed fibrillated acrylic pulp is added into a microporous layer ink. Alternatively, the bloomed fibrillated acrylic pulp can first be disposed on the carbon fiber mat, with the microporous layer ink added thereafter. When the microporous layer ink/bloomed fibrillated acrylic pulp mixture is coated on the carbon fiber mat, the ink penetrates through the open substrate, and is locked into place by the bloomed acrylic pulp fibers. This allows for a buildup of microporous layer ink on top of the substrate for added thickness when the bloomed fibrillated acrylic pulp sits on top of the mat.

Abstract: The present invention provides a fuel cell having a first diffusion and a second diffusion media having a membrane electrode assembly disposed therebetween. The first diffusion media includes a first set of material characteristics and the second diffusion media includes a second set of material characteristics. The first set of material characteristics has at least one material characteristic substantially different from those same material characteristics of the second set of material characteristics. The difference in material characteristics provides for enhancing water management across a major face of the second diffusion media.

Abstract: A diffusion medium for use in a PEM fuel cell comprising a thin perforated layer having variable size and frequency of perforation patterns incorporated into a microporous layer on a first side of a porous substrate layer, wherein the diffusion medium is adapted to improve water management and performance of the fuel cell.

Abstract: Diffusion media for fuel cell is made by preparing an aqueous dispersion comprising a powder resin, a binder material, and a fiber material comprising carbon fibers, of these; forming a layer of the dispersion on a support; removing water from the layer to form a fiber layer; molding the fiber layer; and carbonizing or graphitizing the molded layer.

Abstract: A gas diffusion media for a fuel cell, such as a proton exchange membrane fuel cell, is provided. The gas diffusion media includes carbonizable acrylic pulp fibers instead of conventional phenolic resin as a binder material. The acrylic fibers are mixed with the carbon fiber dispersion during the papermaking step, thus eliminating the phenolic resin impregnation step typically associated with conventional gas diffusion media manufacturing processes. The mat is then cured and carbonized to produce gas diffusion media.

Abstract: Fuel cells contain diffusion media having vapor-deposited fluorocarbon polymers on a conductive substrate. A diffusion medium for use in a PEM fuel cell contains hydrophobic and hydrophilic areas for improved water management.

Abstract: A process comprising: providing a substrate with a catalyst layer thereon; depositing a first ionomer overcoat layer over the catalyst layer, the first ionomer overcoat layer comprising an ionomer and a first solvent; drying the first ionomer overcoat layer to provide a first electrode ionomer overcoat layer; depositing a second ionomer overcoat layer over the first electrode ionomer overcoat layer, and wherein the second ionomer overcoat layer comprises an ionomer and a second solvent.

Abstract: A process comprising: depositing a liquid bonding layer comprising an ionomer and a solvent over a carrier film; placing a decal substrate over the liquid bonding layer and drying the liquid bonding layer to provide a solid bonding layer comprising the ionomer, and the solid bonding layer bonding the decal substrate and carrier film together.

Abstract: An electroconductive porous substrate such as carbon fiber paper with an electroconductive polymer deposited on the carbon fibers of the paper is used as a wicking material or diffusion medium in a fuel cell. The polymer may be deposited from a solution of monomers by electrochemical polymerization.

Abstract: Gas diffusion media for use in fuel cells are provided that contain a pattern of deposited hydrophobic polymer such that less than 100% of the surface of the diffusion media is covered with hydrophobic polymer. The media are made by first wetting a sheet of carbon fiber paper in an aqueous emulsion of the hydrophobic polymer. The wetted sheet is contacted with a pattern member containing one or more openings oriented to correspond to a predetermined or desired pattern of hydrophobic polymer deposition. While still in contact with the pattern member, the sheet is heated or otherwise treated to cause evaporation of the water from the sheet. Evaporation while in contact with the pattern member takes place in such a way that hydrophobic polymer is concentrated in the sheet at the openings of the pattern member by the process of evaporation.

Abstract: Diffusion media for use in PEM fuel cells are provided with silicone coatings. The media are made of a porous electroconductive substrate, a first hydrophobic fluorocarbon polymer coating adhered to the substrate, and a second coating comprising a hydrophobic silicone polymer adhered to the substrate. The substrate is preferably a carbon fiber paper, the hydrophobic fluorocarbon polymer is PTFE or similar polymer, and the silicone is moisture curable.

Abstract: A fuel cell including a water blocking layer positioned between anode gas flow channels and a gas diffusion media. The blocking layer prevents water from propagating through the gas diffusion media layer and entering the anode flow channels, while allowing gas from the flow channels to flow through the diffusion media layer to the membrane. A water accumulation channel can be provided around the perimeter of the gas diffusion media layer where blocked water is accumulated, and allowed to expand during cell freezing. A porous capillary wick can be provided in the accumulation channel for wicking water to the inlet end of the flow channels where it is used to humidify the anode gas coming into the fuel cell. The wick can have a tapered configuration so that it has a larger diameter at the gas input end of the flow channels.

Abstract: A diffusion media and micro-porous media combination for a fuel cell. A diffusion layer is composed of a diffusion media and has a first (electrode) side and an opposite second (flowfield) side, wherein at least one of the first and second sides has a geometric pattern formed therein comprising a multiplicity of mutually spaced apart regions. A micro-porous media fills the multiplicity of regions and a micro-porous layer composed of the micro-porous media is continuously applied to the first surface.

Abstract: A multi-layer diffusion medium substrate having improved mechanical properties is disclosed. The diffusion medium substrate includes at least one stiff layer and at least one compressible layer. The at least one stiff layer has a greater stiffness in the x-y direction as compared to the at least one compressible layer. The at least one compressible layer has a greater compressibility in the z direction. A method of fabricating a multi-layer diffusion medium substrate is also disclosed.

Abstract: In at least certain embodiments, the present invention provides a diffusion media and fuel cells and systems employing the diffusion media. In at least one embodiment, the diffusion media comprises a porous matrix having an outer surface and a hydrophilic polymeric coating on at least a portion of the porous matrix with the hydrophilic coating comprising the cured product of a formulation comprising a hydrophilic monomer.

Abstract: Favorable performance of diffusion media in fuel cells has found to be correlated to a parameter (the C/F ratio) that relates to a spatial and thickness distribution of the hydrophobic fluoropolymer on the carbon fiber substrate structure of the medium. Suitable diffusion media may be chosen from among commercially coated diffusion media by measuring the C/F ratio by means of energy dispersive spectroscopy, and choosing the diffusion media if the value of the C/F ratio is within the preferred range. Alternatively, the diffusion media may be manufactured with an improved process that consistently yields values of C/F ratio in the desired range.

Abstract: Specially prepared gas diffusion media improve the performance of PEM fuel cells. The media are made by first dipping an electrically conductive porous material such as carbon fiber paper into a suspension of hydrophobic polymer and drying the paper to create a desired deposition pattern of hydrophobic polymer on the substrate. Then a paste containing a fluorocarbon polymer and carbon particles is applied to a desired side of the substrate, and thereafter the paste and hydrophobic polymer are sintered together at high temperature on the paper. In particular, nonionic surfactants remain on the carbon fiber paper after the initial hydrophobic polymer is applied to the electrically conductive porous material. When the paste is coated on the dried paper, the paste is in contact with a hydrophilic surface.

Abstract: A bipolar plate for use in a proton exchange membrane fuel cell having an electrically conductive polymer coated on at least one region of a surface of the plate in contact with a flow field. The coated region is hydrophobic or hydrophilic as compared to an uncoated region of the surface to prevent liquid accumulation. Electroconductive polymer coatings are applied by electrochemical polymerization.