Abstract: A fuel cell includes a membrane electrode assembly, a first separator, and a second separator. The membrane electrode assembly includes a solid polymer electrolyte membrane, a first electrode, a second electrode, and a resin frame member. The membrane electrode assembly includes a power generation section and a stepped section. The power generation section is located in an interior space of the resin frame member. The solid polymer electrolyte membrane is provided between the first electrode and the second electrode in the power generation section. The stepped section is located on an outer side of the first electrode. The solid polymer electrolyte membrane is provided between the second electrode and the resin frame member in the stepped section. A magnitude of an interference in the stepped section is set to be smaller than a magnitude of an interference in the power generation section.

Abstract: An example of a stable electrode structure is to use a gradient electrode that employs large platinum particle catalyst in the close proximity to the membrane supported on conventional carbon and small platinum particles in the section of the electrode closer to a GDL supported on a stabilized carbon. Some electrode parameters that contribute to electrode performance stability and reduced change in ECA are platinum-to-carbon ratio, size of platinum particles in various parts of the electrode, use of other stable catalysts instead of large particle size platinum (alloy, etc), depth of each gradient sublayer. Another example of a stable electrode structure is to use a mixture of platinum particle sizes on a carbon support, such as using platinum particles that may be 6 nanometers and 3 nanometers. A conductive support is typically one or more of the carbon blacks.

Abstract: A fuel cell has a membrane electrode assembly forming a catalytic reaction plane region, a gas diffusion layer disposed on a main surface of the membrane electrode assembly, a separator disposed on a main surface of the gas diffusion layer, an electroconductive member, which is disposed between the gas diffusion layer and the separator and outside the catalytic reaction plane region, and which electrically connects the gas diffusion layer and the separator, and a penetration resistance reduction member that makes a penetration resistance between the gas diffusion layer and the separator, passing through the electroconductive member, smaller than a penetration resistance between the gas diffusion layer and the separator in the catalytic reaction plane region.

Abstract: A fuel cell has a membrane electrode assembly including an electrolyte membrane, catalyst layers disposed on both sides of the electrolyte membrane, and three or more layers of porous bodies disposed on a front surface side of the catalyst layer, a frame body surrounding an outer periphery of the electrolyte membrane, and a separator that partitions and forms a gas passage between the membrane electrode assembly and the separator. Extended portions are provided at an outer edge of a first porous body adjacent to the separator among the three layers of the porous bodies, and at an outer edge of a second porous body adjacent to the first porous body, respectively, so as to extend to be superimposed over the frame body. The extended portions of the first and second porous bodies intervene between the frame body and the separator.

Abstract: A gas diffusion medium for a fuel cell includes a microporous region [A], an electrode base material, and a microporous region [B] arranged in the order mentioned, wherein the microporous region [A] has an areal ratio of 5 to 70%, and the microporous region [B] has an areal ratio of 80 to 100%.

Abstract: A membrane electrode assembly includes a proton exchange membrane, a first electrode and a second electrode. The proton exchange membrane has two opposite surfaces, a first surface and a second surface. The first electrode is located adjacent to the first surface of the proton exchange membrane, and the first electrode includes a first diffusion layer and a first catalyst layer. The second electrode is located adjacent to the second surface of the proton exchange membrane, and the second electrode includes a second diffusion layer and a second catalyst layer. At least one of the first diffusion layer and the second diffusion layer includes a carbon nanotube structure. A fuel cell using the membrane electrode assembly is also provided.

Abstract: A membrane electrode assembly for a fuel cell is provided that includes a membrane, electrodes on both sides of the membrane, respectively, and sub-gaskets bonded to the edges of the electrodes, respectively. In particular, the sub-gasket may be bonded to the membrane at a predetermined distance from the edge of the electrode.

Abstract: A fuel cell is disclosed comprising: a power generation layer including an electrolyte membrane, and an anode and a cathode provided on respective surfaces of the electrolyte membrane; a fuel gas flow path layer located on a side of the anode of the power generation layer to supply a fuel gas to the anode while flowing the fuel gas along a flow direction of the fuel gas approximately orthogonal to a stacking direction in which respective layers of the fuel cell are stacked; and an oxidizing gas flow path layer located on a side of the cathode of the power generation layer to supply an oxidizing gas to the cathode while flowing the oxidizing gas along a flow direction of the oxidizing gas opposed to the flow direction of the fuel gas.

Abstract: A fuel cell comprises an electrolyte membrane; first and second catalyst layers formed on respective faces of the electrolyte membrane; and first and second reinforcing layers holding therebetween the electrolyte membrane and the first and second catalyst layers, wherein the first catalyst layer and the first reinforcing layer are joined together with a force of not less than a specific joint strength that suppresses expansion and contraction of the electrolyte membrane, and the second catalyst layer and the second reinforcing layer are joined together with a force of less than a specific joint strength that releases a stress due to expansion and contraction of the electrolyte membrane, or the second catalyst layer and the second reinforcing layer are not joined together.

Abstract: Provided is a gas decomposition component that employs an electrochemical reaction and can have high treatment performance, in particular, an ammonia decomposition component. The gas decomposition component includes a MEA 7 including a solid electrolyte 1 and an anode 2 and a cathode 5 that are disposed so as to sandwich the solid electrolyte; Celmets 11s electrically connected to the anode 2; a heater 41 that heats the MEA; and an inlet 17 through which a gaseous fluid containing a gas is introduced into the MEA, an outlet 19 through which the gaseous fluid having passed through the MEA is discharged, and a passage P extending between the inlet and the outlet, wherein the Celmets 11s are discontinuously disposed along the passage P and, with respect to a middle position 15 of the passage, the length of the Celmets disposed is larger on the side of the outlet than on the side of the inlet.

Abstract: New polymeric networks bearing benzimidazole units have been prepared. These polymeric networks will combine high proton conductivity, superior mechanical properties and thermal and oxidative stability due to the existence of polar benzimidazole groups and the presence of the unique polymeric architecture. The prepared polymer networks can be used in the catalyst ink of the electrodes in high temperature PEM fuel cells.

Abstract: A membrane electrode assembly includes a proton exchange membrane and at least one electrode. The at least one electrode includes a carbon nanotube composite structure. The carbon nanotube composite structure includes a carbon nanotube structure and a catalyst material. The carbon nanotube structure includes a plurality of carbon nanotubes and the catalyst material is dispersed on the carbon nanotubes. A fuel cell using the membrane electrode assembly is also provided.

Abstract: The invention relates to a membrane-electrode assembly (100), comprising two electrodes (110, 110?) and a membrane (120), preferably a polymer electrolyte membrane (PEM), which is disposed between the two electrodes (110, 110?), wherein the membrane-electrode assembly (100) comprises a first cover layer (130; 130?) and a second cover layer (140; 140?) on at least one flat side, preferably on both flat sides of the membrane (120), characterized in that the first cover layer (130; 130?) covers an edge face (125, 125?) of the membrane (120) and an electrode edge face (115, 115?) facing the membrane (120) and the second cover layer (140; 140?) partially covers the first cover layer (130; 130?), preferably in edge regions of the membrane-electrode assembly (100). The present invention further relates to a fuel cell which comprises a membrane-electrode assembly (100).

Abstract: A fuel cell includes a cathode having a first gas diffusion layer and a first catalyst layer, an anode including a second gas diffusion layer and a second catalyst layer and a proton exchange membrane disposed between the cathode and anode. A microporous layer is disposed between the first gas diffusion layer and the first catalyst layer. The microporous layer defines a plurality of domains extending between opposite surfaces of the microporous layer. Under freezing conditions the microporous layer is arranged to concentrate ice formation within the domains to reduce an amount of frozen water within the catalyst layer.

Abstract: Disclosed is a carbon fiber web including polymer nanofibers. Specifically, the carbon fiber web includes: a dispersed structure of carbon fibers; and polymer nanofibers distributed among and bonding the constituent carbon fibers of the dispersed structure. The carbon fiber web exhibits excellent characteristics in terms of flexural strength, gas permeability and electrical properties while possessing a tensile strength sufficient to undergo continuous processes for mass production. Also disclosed are a gas diffusion medium using the carbon fiber web, a gas diffusion layer including the gas diffusion medium, a membrane electrode assembly including the gas diffusion layer, and a fuel cell including the membrane electrode assembly. The use of the carbon fiber web ensures high performance of the membrane electrode assembly and the fuel cell.

Abstract: In an AMFC, in the formation of a CCM, the anode catalyst layer is selectively cross-linked while the cathode catalyst layer is not cross-linked. This has been found to provide structural stabilization of the CCM without loss of initial power value for a CCM without cross-linking.

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 non-woven gas diffusion substrate including: (i) a non-woven carbon fibre web; (ii) a carbon particulate material; and 10 (iii) a hydrophobic binder characterised in that the non-woven gas diffusion substrate further includes a conductive material having a x:y aspect ratio from 0.01 to 100, a x:z aspect ratio of at least 500 and a y:z aspect ratio of at least 500.

Abstract: In solid polymer fuel cells employing framed membrane electrode assemblies, a conventional anode compliant seal is employed in combination with a cathode non-compliant seal to provide for a thinner fuel cell design, particularly in the context of a fuel cell stack. This approach is particularly suitable for fuel cells operating at low pressure.

Abstract: An electrochemistry apparatus comprises a supporting body and a reaction layer for generating electromotive force. The supporting body is made of a first material. The reaction layer covers the surface of the supporting body and comprises an ion conductive layer, a first film electrode and a second film electrode. The first and the second film electrodes are separately formed on two opposite surfaces of the ion conductive layer. The ion conductive layer is made of a second material having a thermal expansion coefficient approximating to the thermal expansion coefficient of the first material. The second material has an ionic conductivity greater than the ionic conductivity of the first material. The first material has a toughness greater than the second material. The electrochemistry apparatus employs the supporting body with improved toughness and the ion conductive layer with improved ion conductivity, so as to increase sensitivity and thermal shock resistance.

Abstract: A cell for a fuel cell, having an electric power generation region in which an assembly 12 and first and second gas diffusion layers 14 are laminated to enable electric power generation, and a manifold region which is formed at the periphery of the electric power generation region and in which manifold openings 18 are formed to allow the passage of a gas or the like, wherein one of the first and second gas diffusion layers 14 extends to the manifold region, and a peripheral edge portion 14c is hermetically sealed by impregnation with a liquid resin that is used for forming a gasket 16 around the periphery of the manifold opening 18. The porosity of a boundary portion 14b of the first and second gas diffusion layers 14 is smaller than the porosity of the electric power generation region 14a and the peripheral edge portion 14c.

Abstract: A fuel cell includes a membrane electrode assembly having an anode side and a cathode side, a first gas diffusion layer adjacent the cathode side of the membrane electrode assembly, and a first flow field plate contacting the first gas diffusion layer. The first flow field plate includes a reactant inlet, a reactant outlet, and a plurality of flow field chambers separated from one another by at least one rib. The reactant inlet is separated from the plurality of flow field chambers by at least one rib and the reactant outlet is separated from the plurality of flow field chambers by at least one rib. The ribs are configured to force a reactant flowing from the reactant inlet to the reactant outlet to enter the first gas diffusion layer at least twice.

Abstract: A gas diffusion layer contains a substrate formed of a carbon containing material and a micro porous layer. The gas diffusion layer can be obtained by dispersing carbon black with a BET surface area of at most 200 m2/g, carbon nanotubes with a BET surface area of at least 200 m2/g and with an average outer diameter of at most 25 nm and a dispersion medium at a shearing rate of at least 1,000 seconds?1 and/or such that, in the dispersion produced, at least 90% of all carbon nanotubes have a mean agglomerate size of at most 25 ?m. The dispersion is applied to at least one portion of at least one side of the substrate, and the dispersion is dried.

Abstract: The present invention pertains to a fuel cell with a storage unit (4) for storing hydrogen (Hx), with a proton conductive layer, which covers a surface of the storage unit (4), and with a cathode (7) on a side of the proton conductive layer, which side is located opposite, wherein the storage unit (4) is directly coupled with an anode and/or the storage unit (4) is incorporated in a substrate (1) of a semiconductor. The storage unit (4) is preferably connected to the substrate (1) at least via a stress compensation layer (3).

Abstract: A substrate 10 that selectively allows hydrogen to permeate therethrough is formed with a catalyst thin layer 20 on a first side 11 thereof and is heated in a furnace tube 110, which functions as a reactor, of a heating furnace 100 while a raw material gas to the catalyst thin layer 20 is fed. Hydrogen produced on the first side 11 of the substrate 10 as a result of the formation of carbon nanotubes 5 is separated from the raw material gas and is allowed to permeate to a second side 12 thereof.

Abstract: A method including providing a substrate; treating the substrate to form a passive layer, wherein the passive layer has a thickness of at least 3 nm; and depositing an electrically conductive coating over the substrate, wherein the coating has a thickness of about 0.1 nm to about 50 nm.

Abstract: Provided is an electrocatalyst for solid polymer fuel cells capable of increasing the active surface area for reactions in a catalyst component, increasing the utilization efficiency of the catalyst, and reducing the amount of expensive precious metal catalyst used. Also provided are a membrane electrode assembly that uses this electrocatalyst and a solid polymer fuel cell. An electrocatalyst for a solid polymer fuel cell is provided with a catalyst and solid proton conducting material. A liquid conductive material retention part that retains a liquid proton conducting material that connects the catalyst and solid proton conducting material is provided between the same. The surface area of the catalyst exposed within the liquid conductive material retention part is larger than the surface area of the catalyst in contact with the solid proton conducting material.

Abstract: An electrocatalytic polymer-based powder has particles of at least one electronically conductive polymer species in which particles are dispersed of at least one catalytic redox species, in which the particles of the polymer species and of the catalytic species are of nanometric dimension.

Abstract: A cell structure for a fuel-cell battery, which allows the compromise necessary between the reduction in the non-uniformities of mechanical stress to be optimized, with the aim of obtaining a more uniform operation, and the independent accommodation with respect to the defects in planarity/thickness/alignment, while at the same time meeting the compactness constraint, comprises: a membrane/electrode assembly comprising a first electrode and a second electrode separated by a membrane; a gas diffusion layer stacked on each face of the assembly, between an electrode of the assembly and a current collector plate; and the gas diffusion layers stacked on either side of the assembly do not have the same rigidity, one of the gas diffusion layers having a Young's modulus relative to an applied stress in the direction of the thickness, greater than the Young's modulus of the other layer, in a ratio of the order of at least 100.

Abstract: It is an object of the present invention to provide an oxygen reducing catalyst having high catalytic activity and high durability using a transition metal (such as titanium); and a method for producing a fuel cell electrode catalyst using the oxygen reducing catalyst. The present invention provides the oxygen reduction catalyst including titanium, carbon, nitrogen, and oxygen as constituent elements at a specific ratio, wherein in XRD measurement using a Cu—K? ray, peaks are each present in at least regions A and B among regions A to D which occupy 2? ranges of 42° to 43°, B: 36.5° to 37°, 25° to 26°, and 27° to 28°, respectively; and each of maximum peak intensities IA, IB, IC, and ID in the regions A to D satisfies both relationships of IA>IB and 0.3?(IA/(IA+IC+ID))?1.

Abstract: A membrane-electrode assembly includes: a polymer electrolyte membrane; catalyst layers disposed on the polymer electrolyte membrane; and gas diffusion layers respectively disposed on the catalyst layers. Each of the gas diffusion layers is constituted by a porous member containing electrically-conductive particles and polymer resin as major components, and a ratio (y/x) of a tensile strength y (N/cm) of the gas diffusion layer to a dry-wet size change rate x (%) of the polymer electrolyte membrane is 0.10 or higher.

Abstract: Provided is a method of manufacturing a membrane electrode assembly including catalyst layers in both sides of a polymer electrolyte membrane, substance diffusion of the catalyst layer being improved, in which forming at least one of the catalyst layers includes at least: forming a first layer including one of a catalyst and a catalyst precursor on a surface of a sheet by vapor-phase deposition; forming a through hole in the first layer; forming a second layer including one of a catalyst and a catalyst precursor on a surface of the first layer having the through hole by vapor-phase deposition; joining a polymer electrolyte membrane to a surface of the second layer; and peeling off the sheet from the first layer.

Abstract: A fuel cell includes a solid polymer electrolyte membrane, and a cathode separator and an anode separator sandwiching a solid polymer electrolyte membrane therebetween. The fuel cell includes an oxidant gas channel including a plurality of wave-shaped channel portions extending in a horizontal direction. Part of one of the plurality of wave-shaped channel portions that is disposed at the lower end in the vertical direction protrude downward from a planar region of electrode catalyst layers, i.e. a power generation region, in the vertical direction.

Abstract: A process for producing an oxygen reducing catalyst including a step of heat-treating, in a non-oxidizing atmosphere, a catalyst precursor including a compound (i) supplying a carbon element and a nitrogen element by heating in a non-oxidizing atmosphere, and a compound (ii) containing at least one element of iron and cobalt. Also disclosed is an oxygen reducing catalyst, a fuel cell catalyst layer including the oxygen reducing catalyst, an electrode including the fuel cell catalyst layer, a membrane-electrode assembly including the electrode and a fuel cell including the membrane-electrode assembly.

Abstract: A catalyst slurry for a fuel cell, an electrode manufactured using the catalyst slurry, a membrane-electrode assembly including the electrode, a fuel cell including the membrane-electrode assembly, and a method of manufacturing the electrode are provided. The catalyst slurry includes a catalyst material, an acid component, a binder, and a solvent component having a viscosity of at least about 20 cps at about 20° C.

Abstract: A fuel cell includes a membrane electrode assembly and a first separator. The first separator includes a first reactant gas channel, a first reactant gas manifold, and a first buffer portion. The first buffer portion is located outside of a power generation region of an electrode catalyst layer of the first electrode. The first buffer portion connects the first reactant gas channel to the first reactant gas manifold. A gas diffusion layer of the first electrode extends along a surface of the first separator to a first buffer region facing the first buffer portion. An intermediate layer of the first electrode covers a portion of the gas diffusion layer of the first electrode in the first buffer region.

Abstract: A fuel cell stack includes membrane-electrode assemblies and separators that are closely disposed to both sides of the membrane-electrode assembly. Each membrane-electrode assembly includes an electrolyte membrane, an anode electrode that is formed on one surface of the electrolyte membrane, a cathode electrode that is formed on the other surface of the electrolyte membrane, and a protective layer formed at an oxidant inlet region where oxidant is first injected into the respective cathode electrode.

Abstract: A gas diffusion layer (30) for a fuel cell includes: a gas diffusion layer substrate (31); and a microporous layer (32) containing a granular carbon material and scale-like graphite and formed on the gas diffusion layer substrate (31). The microporous layer (32) includes a concentrated region (32a) of the scale-like graphite that is formed into a belt-like shape extending in a direction approximately parallel to a junction surface (31a) between the microporous layer (32) and the gas diffusion layer substrate (31). Accordingly, both resistance to dry-out and resistance to flooding, which are generally in a trade-off relationship, in the gas diffusion layer can be ensured so as to contribute to an increase in performance of a polymer electrolyte fuel cell.

Abstract: A reactant flow field (19, 21) has multiple flow field channels (30, 32) and chambers (34). The multiple flow field channels (30, 32) and chambers (34) require reactant entering the flow field (19, 21) to traverse a flow transition (38) multiple times before exiting the flow field (19, 21).

Abstract: A microporous layer sheet for a fuel cell according to the present invention includes at least two microporous layers, which are stacked on a gas diffusion layer substrate, and contain a carbon material and a binder. Then, the microporous layer sheet for a fuel cell is characterized in that a content of the binder in the microporous layer as a first layer located on the gas diffusion layer substrate side is smaller than contents of the binder in the microporous layers other than the first layer. The microporous layer sheet for a fuel cell, which is as described above, can ensure gas permeability and drainage performance without lowering strength. Hence, the microporous layer sheet for a fuel cell, which is as described above, can contribute to performance enhancement of a polymer electrolyte fuel cell by application thereof to a gas diffusion layer.

Abstract: The present invention relates to a fuel cell system. A hot zone chamber has a wall thickness T and a heat source coupled thereto. An elongate fuel cell device is positioned with a first lengthwise portion within the hot zone chamber, a second lengthwise portion outside the hot zone chamber, and a third lengthwise portion of length T within the chamber wall. The third portion has a maximum dimension L in a plane transverse to the length where T?½L.

Abstract: A fuel cell of the present invention is configured so that seal members are brought into contact with a frame member, and at least one of the seal member and an outer circumferential portion of the gas diffusion layer is squashed by the other in the thickness direction of a polymer electrolyte membrane, to eliminate a clearance between the gas diffusion layer and the seal member. In this manner, the power generation performance is further enhanced.

Abstract: A gas diffusion layer for a fuel cell includes a gas diffusion layer substrate and a microporous layer formed on the surface of the gas diffusion layer substrate. The microporous layer is formed into a sheet-like shape including a binder and a carbon material containing at least scale-like graphite, and the sheet-like microporous layer is attached to the gas diffusion layer substrate. The gas diffusion layer for a fuel cell having such a configuration, prevents the components included in the microporous layer from entering the gas diffusion layer substrate, so as to ensure gas permeability. In addition, the scale-like graphite contained in the microporous layer as an electrically conductive material improves electrical conductivity and gas permeability. Accordingly, the gas diffusion layer contributes to an improvement in performance of a polymer electrolyte fuel cell.

Abstract: In an electrode-membrane-frame assembly production method, a principal part is formed by an electrolyte membrane, first and second catalyst layers and first and second gas diffusion layers, with the first and second gas diffusion layers arranged with their outer circumferences at different positions. The principal part is arranged in a molding die with a circumferential region of the principal part disposed on a flat region of a primary molded body. A circumferential portion of one of the gas diffusion layers is arranged to oppose a flat region of the primary molded body so that the membrane is interposed between the circumferential portion and the flat region. Subsequently, a secondary molded body is formed to integrate with the primary molded body and the principal part.

Abstract: A membrane electrode assembly (MEA) for a fuel cell comprising a gradient catalyst structure and a method of making the same. The gradient catalyst structure can include a plurality of catalyst nanoparticles, e.g., platinum, disposed on layered buckypaper. The layered buckypaper can include at least a first layer and a second layer and the first layer can have a lower porosity compared to the second layer. The gradient catalyst structure can include single-wall nanotubes, carbon nanofibers, or both in the first layer of the layered buckypaper and can include carbon nanofibers in the second layer of the layered buckypaper. The MEA can have a catalyst utilization efficiency of at least 0.35 gcat/kW or less.

Abstract: An arrangement for interconnecting electrochemical cells of the type having a membrane electrode assembly (MEA) interposed between an anode gas diffusion layer (208) and a cathode gas diffusion layer (210), and first and second current collectors coupled to said anode and cathode gas diffusion layers (GDL), respectively, wherein the first current collector extends from the anode side of one cell to the cathode side of an adjacent cell, and wherein the cell components are clamped together. The first current collector (206) which is in contact with the anode gas diffusion layer (GDL; 208) of a first electrochemical cell (200a) is configured to be connected to the cathode side of a second, adjacent electrochemical cell (200b) via an inert and electrically conductive member (204b), without being in electrochemical contact with the electrochemically active components of the adjacent cell.

Abstract: The present invention provides a membrane electrode assembly that enhances the reliability, mechanical strength, and handling characteristics of a seal in a solid polymer electrolyte fuel cell. The membrane electrode assembly of the present invention comprises a membrane-electrode structure having electrode layers and gas diffusion layers on both sides of a polymer electrolyte membrane, and a resin frame provided in such a manner as to fully enclose the outer periphery of the electrolyte membrane and to enclose at least portions of the outer peripheries of the gas diffusion layers, the resin frame being provided so as to enclose the electrolyte membrane side. The gas diffusion layer and electrode layer on one side are stacked on a surface of the electrolyte membrane so that a surface region of the electrolyte membrane is left exposed. The gas diffusion layer on the opposite side extends all around the outer periphery of the electrolyte membrane.

Abstract: An inorganic proton conductor for an electrochemical device and an electrochemical device using the inorganic proton conductor, the inorganic proton conductor including a tetravalent metallic element and an alkali metal.

Abstract: A fuel cell includes a membrane electrode assembly interposed between a cathode-side separator and an anode-side separator. A first gas diffusion layer included in a cathode is designed to have a planar size larger than a planar size of a second gas diffusion layer included in an anode. The anode-side separator has a thin clearance part in a portion that faces an outer peripheral portion of the second gas diffusion layer.

Abstract: Fuel-cell membrane-subgasket assemblies may include an electrolyte membrane and a coated subgasket overlying the electrolyte membrane around a perimeter of the electrolyte membrane so as to define an active area inside the perimeter. The coated subgasket may comprise a subgasket body formed from a subgasket material. At least one side of the coated subgasket includes a subgasket coating layer containing or formed from a coating material such as metals, ceramics, polymers, polymer composites, or other hard coatings. Fuel-cell assemblies may include gas diffusion media, a bipolar plate, and a fuel-cell membrane-subgasket assembly having a coated subgasket. Fuel-cell stacks may include clamping plates, unipolar endplates, and a plurality of individual fuel-cell assemblies, at least one of which includes a fuel-cell membrane-subgasket assembly having a coated subgasket.