5138 results about "Membrane electrode assembly" patented technology

PCT No. PCT/US95/13325 Sec. 371 Date Sep. 28, 1997 Sec. 102(e) Date Sep. 28, 1997 PCT Filed Oct. 10, 1995 PCT Pub. No. WO96/12316 PCT Pub. Date Apr. 25, 1996Fuel cell stacks comprising stacked separator/membrane electrode assembly fuel cells in which the separators comprise a series of thin sheet platelets, having individually configured serpentine micro-channel reactant gas humidification active areas and cooling fields therein. The individual platelets are stacked with coordinate features aligned in contact with adjacent platelets and bonded to form a monolithic separator. Post-bonding processing includes passivation, such as nitriding. Preferred platelet material is 4-25 mil Ti, in which the features, serpentine channels, tabs, lands, vias, manifolds and holes, are formed by chemical and laser etching, cutting, pressing or embossing, with combinations of depth and through etching preferred. The platelet manufacturing process is continuous and fast. By employing CAD based platelet design and photolithography, rapid change in feature design can accommodate a wide range of thermal management and humidification techniques. One hundred H2-O2/PEM fuel cell stacks of this IFMT platelet design will exhibit outputs on the order of 0.75 kW/kg, some 3-6 times greater than the current graphite plate PEM stacks.

The present invention discloses nanowires for use in a fuel cell comprising a metal catalyst deposited on a surface of the nanowires. A membrane electrode assembly for a fuel cell is disclosed which generally comprises a proton exchange membrane, an anode electrode, and a cathode electrode, wherein at least one or more of the anode electrode and cathode electrode comprise an interconnected network of the catalyst supported nanowires. Methods are also disclosed for preparing a membrane electrode assembly and fuel cell based upon an interconnected network of nanowires.

The application relates to a method of fabricating micro fuel cells and membrane electrode assemblies by thin film deposition techniques using a dimensionally stable proton exchange membrane as a substrate. The application also relates to membrane electrode assemblies and fuel cells fabricated in accordance with the method. The method includes the steps of successively depositing catalyst, current collector and flow management layers on the membrane substrate in predetermined patterns. Since the fuel cell is formed layer by layer, the need for assembly and sealing of discrete components is avoided. The method improves the contact resistance between the current collectors and catalyst layers and reduce ohmic losses, thereby avoiding the need for end plates or other compressive elements. This in turn reduces the overall thickness of the manufactured fuel cell. Since the fuel cell layers are optionally flexible, the devices may be fabricated using a continuous roller process or other automated means. The method minimizes production costs and costs of non-essential materials and is particularly suitable for low power battery replacement applications.

A significant problem in PEM fuel cell durability is in premature failure of the ion-exchange membrane and in particular by the degradation of the ion-exchange membrane by reactive hydrogen peroxide species. Such degradation can be reduced or eliminated by the presence of an additive in the anode, cathode or ion-exchange membrane. The additive may be a radical scavenger, a membrane cross-linker, a hydrogen peroxide decomposition catalyst and/or a hydrogen peroxide stabilizer. The presence of the additive in the membrane electrode assembly (MEA) may however result in reduced performance of the PEM fuel cell. Accordingly, it may be desirable to restrict the location of the additive to locations of increased susceptibility to membrane degradation such as the inlet and/or outlet regions of the MEA.

A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various thermoplastc polymers for high temperature polymer electrolyte fuel cells have also been developed. Miscible blends are used for solution casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes. With the thermally resistant polymer, e.g., polybenzimidazole or a mixture of polybenzimidazole and other thermoplastics as binder, the carbon-supported noble metal catalyst is tape-cast onto a hydrophobic supporting substrate. When doped with an acid mixture, electrodes are assembled with an acid doped solid electrolyte membrane by hot-press. The fuel cell can operate at temperatures up to at least 200° C. with hydrogen-rich fuel containing high ratios of carbon monoxide such as 3 vol % carbon monoxide or more, compared to the carbon monoxide tolerance of 10-20 ppm level for Nafion®-based polymer electrolyte fuel cells.

An electrolyte membrane is prepared from a liquid composition comprising at least one member selected from the group consisting of trivalent cerium, tetravalent cerium, bivalent manganese and trivalent manganese; and a polymer with a cation-exchange group. The liquid composition is preferably one containing water, a carbonate of cerium or manganese, and a polymer with a cation-exchange group, and a cast film thereof is used as an electrolyte membrane to prepare a membrane-electrode assembly. The present invention successfully provides a membrane-electrode assembly for polymer electrolyte fuel cells being capable of generating the electric power in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas, and being capable of stably generating the electric power over a long period of time.

A membrane electrode assembly for a polymer electrolyte fuel cell characterized by using, as solid polyelecrolyte of at least one of a membrane and a catalyst binder, a fluorinated sulfonic acid polymer with a monomer unit represented by the following general formula (3):

(wherein Rf¹ is a bivalent perfluoro-hydrocarbon group having a carbon number of from 4 to 10), wherein said fluorinated sulfonic acid polymer has melt flow rate (MFR) not higher than 100 g/10 min at 270° C. when a —SO₃H group in said polymer is converted to —SO₂F.

The present invention concerns improvements in fuel cell fabrication. It concerns an improved, integrated and modular BSP/MEA/Manifolds, which facilitates single cell (module) leak and performance testing prior to assembly in a fuel cell stack as well as facilitating manufacturing and cost reduction. In particular, the present invention relates to a fuel cell, which includes: a) A single flexible or ridged separator plate; b) a flexible membrane electrode assembly; c) a flexible bond interposed between said single flexible or ridged separator plate and said flexible membrane electrode assembly, wherein said flexible bond between said flexible or ridged separator plate and said flexible membrane electrode assembly comprises the fuel cell, and wherein said flexible bond is an adhesive bond which encapsulates edge portions of said flexible or ridged separator plate and said flexible membrane electrode assembly and wherein said flexible bond seals the edge portions of said flexible membrane assembly to prevent the release of reactants from the fuel cell. In some embodiments the adhesive bond comprises a flexible gasket; d) manifold for the delivery and removal of reactants and reactant products to and from the fuel cell reactive areas where said manifolds may be either a single or multiple manifolds; and e) a bond interposed between said manifold and said single flexible or ridged separator plate, wherein said bond affixes said manifold to said flexible or ridged separator plate and wherein said bond provides a seal between said manifold and said flexible or ridged separator plate to prevent the release of reactants from the fuel cell. It also eliminates some gaskets and simplifies assembly.

A membrane electrode assembly includes an anode, a cathode, and a solid polymer electrolyte membrane interposed between the anode and the cathode. The anode and the cathode include gas diffusion layers and electrode catalyst layers. Mixture layers are provided over predetermined areas H around surfaces of the electrode catalyst layers. The electrode catalyst layers and adhesive layers are mixed in the mixture layers, respectively.

The present invention relates to fuel cells and components used within a fuel cell. Heat transfer appendages are described that improve fuel cell thermal management. Each heat transfer appendage is arranged on an external portion of a bi-polar plate and permits conductive heat transfer between inner portions of the bi-polar plate and outer portions of the bi-polar plate proximate to the appendage. The heat transfer appendage may be used for heating or cooling inner portions of a fuel cell stack. Improved thermal management provided by cooling the heat transfer appendages also permits new channel field designs that distribute the reactant gases to a membrane electrode assembly. Flow buffers are described that improve delivery of reactant gases and removal of reaction products. Single plate bi-polar plates may also include staggered channel designs that reduce the thickness of the single plate.

A membrane electrode assembly for polymer electrolyte fuel cells comprises a cathode electrode, an anode electrode, and a polymer electrolyte membrane placed between these electrodes, and a catalyst material of Pt—Ru alloy is contained in the anode and the crystal of Pt—Ru alloy is mainly of a face-centered cubic structure.

A membrane-electrode assembly, containing an electrode catalyst containing a base metal complex, in which exchange current density i₀ obtained from a Tafel plot, which is related to current density and voltage, is 5.0×10⁻⁴ Acm⁻² or more, and in which a Tafel slope obtained from the Tafel plot is 450 mV/decade or less; and

a membrane-electrode assembly, containing catalyst layers each containing an electrode catalyst on both sides of an electrolyte membrane, in which at least one of the catalyst layers comprises a non-noble metal-based electrode catalyst, and in which the electrolyte membrane is a hydrocarbon-based electrolyte membrane.

The present invention relates to a polymer electrolyte fuel cell comprising: an electrolyte membrane-electrode assembly including an anode, a cathode and a polymer electrolyte membrane interposed therebetween; an anode-side conductive separator plate having a gas flow channel for supplying a fuel gas to the anode; and a cathode-side conductive separator plate having a gas flow channel for supplying an oxidant gas to the cathode. A conductive separator plate made of carbon has poor wettability with water. This has posed the disadvantage that variations in performance are induced by nonuniform gas distribution among cells due to the accumulation of product water or humidifying water in the gas flow channel on the surface of the separator plate. The present invention employs a conductive separator plate comprising a conductive carbon having a hydrophilic functional group, at least in a portion of the gas flow channels, thereby preventing water from accumulating in the gas flow channels.

The present invention provides a fuel cell comprising a pair of separators sandwiching outsides of a membrane electrode assembly composed of a pair of electrodes provided on both sides of a solid polymer electrolyte membrane, an outer seal member sandwiched by a pair of separators at a position surrounding an outer periphery of the membrane electrode assembly, an inner seal member sandwiched by one of the pair of separators and an outer periphery of the electrolyte membrane, and a backing member opposing to the inner seal member interposing the electrolyte membrane, wherein steps are formed at contact surfaces of the inner seal member and the outer seal member on one of the pair of separators.

The invention provides a device for automatically assembling a fuel battery galvanic pile and belongs to the technical field of fuel batteries. The device comprises a stander, a pressure adjustable compression device, an automatic guide rod pull and location device and an automatic nut twisting device, wherein the pressure adjustable compression device and the automatic guide rod pull and location device are respectively fixed at two ends of the stander; and the automatic nut twisting device is movably arranged on the stander. By the device, the integration of combination and assembly of a galvanic pile component can be realized, so the automation degree is higher, the operation is convenient and quick, and the assembling efficiency of the fuel battery is improved; by exchanging an upper pressing block and a tray, the device can be applicable to fuel battery galvanic piles of various specifications and sizes, the uniformity is high, and the equipment cost for assembling the fuel batteries of different types can be reduced; by the upper pressing block ,a uniform assembling pressure can be provided, so a bipolar plate inside the galvanic pile is contacted with a membrane electrode assembly (MEA) uniformly, the contact resistance is reduced and the performance of the fuel battery is improved.

A membrane electrode assembly including a gas diffusion layer and a layered structure made up of from 4 to 1000 layers including layers of a first type and layers of a second type, wherein the layers of the first type are electrolyte layers and the layers of the second type are catalyst layers, the layered structure having one or more catalyst functional regions, each made up of layers of the first and second types, and one or more electrolyte functional regions, each made up of layers of the first and second types.

The present invention provides a membrane-electrode assembly for fuel cell which comprises a solid polymer electrolyte membrane comprising a specific polyarylene having a sulfonic acid group and has excellent creep resistance, power generation performance and durability against power generation under high-temperature environment. The membrane-electrode assembly is characterized in that a pair of electrodes each comprising a gas diffusing layer and a catalyst layer are joined to both sides of a solid polymer electrolyte membrane so that the catalyst layer side comes into contact with the membrane, said membrane comprises a sulfonated polyarylene comprising constituent unit represented by the following formula (1):

wherein Y is a group represented by —C(CF₃)₂—, (CF₂)_i—, wherein i is an integer of 1 to 10, —SO— or —SO₂—; Z is a divalent electron-donating group or a direct bond; Ar is an aromatic group having a substituent represented by —SO₃H; m is an integer of 0 to 10; n is an integer of 0 to 10; and k is an integer of 1 to 4.

A dope (24) containing a solvent and a precursor of a solid electrolyte is cast onto a belt (94) to form a casting membrane (61). The casting membrane (61) is immersed in a contact liquid (100) in a liquid bath (83) and peeled as a wet precursor membrane (67) from the belt (94) when having a self-supporting property. The solvent contained in the wet precursor membrane (67) is substituted by the contact liquid (100), and the wet precursor membrane (67) is transported out of the liquid bath (83). After being dried in a tenter device (85), the wet precursor membrane (67) is contacted with a proton solution (110) in a proton substitution chamber (86) to perform proton substitution to the precursor contained in the wet precursor membrane (67), and then dried in a drying chamber (87) to be a solid electrolyte membrane (77).