Abstract: A method of producing electrical power includes: a cathode having a porphyrin precursor attached to a substrate, and having a first enzyme, wherein the first enzyme reduces oxygen; an anode having a first region of an anode substrate and having a gold nanoparticle composition located thereon, and having a second region of the anode substrate having an enzyme composition located thereon, wherein the enzyme composition includes a second enzyme, wherein the first region and second region are separate regions; and a neutral fuel liquid in contact with the anode and cathode, the neutral fuel liquid having a neutral pH and a fuel reagent; and operating the fuel cell to produce electrical power with the neutral fuel liquid having the neutral pH and the fuel reagent.

Abstract: A boron-containing proton-exchange solid support may include a proton-exchange solid support comprising an oxygen atom and a tetravalent boron-based acid group comprising a boron atom covalently bonded to the oxygen atom.

Abstract: Aqueous electrolytes comprising fluorenone/fluorenol derivatives are disclosed. The electrolyte may be an anolyte for an aqueous redox flow battery. In some embodiments, the compound, or salt thereof, has a structure according to any one of formulas I-III where Q1-Q4 independently are CH, C(R1) or N, wherein 0, 1, or 2 of Q1-Q4 are N; Q5-Q8 independently are CH, C(R2), or N, wherein 0, 1, or 2 of Q5-Q8 are N; Y is C?O or C(H)OH; R1 and R2 independently are an electron withdrawing group; n is an integer >1; and x and y independently are 0, 1, 2, 3, or 4, where at least one of x and y is not 0.

Abstract: A catalyst layer comprising an interface to a polyelectrolyte membrane, the catalyst layer includes a layer forming material, which includes a catalytic substance, a conductive carrier which supports the catalytic substance, a polyelectrolyte, and a fibrous material, and a plurality of pores which contain no layer forming material. A pore area ratio which is a total area ratio of the plurality of pores to an area of a cross-section orthogonal to the interface is 25.0% or more and 35.0% or less in a cross-sectional image captured by a scanning electron microscope.

Abstract: A heat treatment apparatus of membrane electrode assemblies includes a base, a first member extending from the base in a first direction, and a plurality of second members formed on the base in a radially outward direction of the first member and having inner surfaces facing the first member, where the first member or the second members includes a heat wire member, and membrane electrode assemblies are disposed between the first member and the second members.

Abstract: A fuel cell single cell includes a pair of separators each having manifold holes, a frame disposed between the separators, a power generating unit disposed in an opening of the frame, and a plurality of gas flow channels configured to connect the power generating unit with the manifold holes. Each of the gas flow channels has a distal channel portion defined by a frame groove provided in the frame and configured to communicate with the manifold holes, and a proximal channel portion defined by a separator groove provided in the corresponding separator and configured to communicate with the power generating unit. Each of the gas flow channels is configured to be independent of adjacent other gas flow channels, at least over a range from a distal end of the distal channel portion, which communicates with the manifold holes, to a point in the proximal channel portion.

Abstract: A fuel cell system includes a fuel cell stack of a plurality of power generation cells and an impedance measuring device for measuring the impedance in the fuel cell stack. When stopping the operation of the fuel cell system, a method for stopping the operation of the fuel cell system operates the plurality of power generation cells to generate electric power, until the impedance value becomes equal to or greater than an objective impedance value. After the impedance value has become equal to or greater than the objective impedance value, the operation stopping method still continues the power generation of the multiple power generation cells for a given period of time.

Abstract: The presently disclosed subject matter relates generally to a highly ionically conductive solid electrolyte membrane and to batteries comprising such solid electrolyte membrane.

Abstract: There is provided a catalyst layer for a fuel cell that can inhibit reduction in water electrolysis function. The catalyst layer for a fuel cell according to this disclosure comprises carbon supports on which Pt particles are supported, and Ir oxide particles, wherein the ratio of the mean primary particle size of the Ir oxide particles with respect to the mean primary particle size of the Pt particles is 20 or greater. The mean primary particle size of the Pt particles may be 20.0 nm or smaller and the mean primary particle size of the Ir oxide particles may be 100.0 nm to 500.0 nm.

Abstract: The present invention relates to a fuel cell and a fuel cell stack comprising the same, and according to one aspect of the present invention, there is provided a fuel cell comprising a membrane-electrode assembly having a first surface and a second surface opposite to the first surface, wherein an anode electrode and a cathode electrode are each disposed on the first surface; an end plate disposed apart at a predetermined interval on the second surface; a first gas diffusion layer disposed on the anode electrode; a second gas diffusion layer disposed on the cathode electrode; a first separating plate disposed on the first gas diffusion layer and having a plurality of flow channels; and a second separating plate disposed on the second gas diffusion layer and having a plurality of flow channels.

Abstract: The present disclosure provides a separator, a lithium metal negative electrode, and a lithium metal secondary battery which include a solid superacid coating layer. The solid superacid coating layer suppresses a growth of lithium dendrites in a lithium metal secondary battery employing lithium metal as a negative electrode by improving a mobility and a reaction uniformity of lithium at an interface of the lithium metal negative electrode and an electrolyte solution. In the lithium metal secondary battery, the solid superacid coating layer comprising solid superacid material having a porous structure is formed on at least one of the lithium metal negative electrode and the separator.

Abstract: Aromatic polymers exhibiting thermal stability and conductivity upon imbibement into an acid are disclosed for electrochemical gas sensor applications. Membrane electrode assemblies for electrochemical gas sensors are also provided, comprising a sensing electrode, a counter electrode, and a polymer membrane comprising the polymers of the present invention, disposed between the sensing electrode and the counter electrode.

Abstract: A separator plate for an electrochemical system is described. The separator plate may be used with a bipolar plate and for an electrochemical system comprising a plurality of bipolar plates. The separator plate may have a flow field and guiding structures for guiding a medium through the flow field. The guiding structures of the flow field have a mean height h1 determined perpendicularly to the planar surface plane of the plate. The separator plate may also have a contiguous, lowered transition region where medium flowing from a channel into the flow field, or from the flow field into the channel, flows through the transition region, wherein the transition region has a maximum height hmax determined perpendicularly to the planar surface plane of the plate, where applies: hmax?0.95·h1.

Abstract: A four-fluid bipolar plate for a fuel cell includes an oxidant flow field, a fuel reactant flow field, a dedicated coolant passage, and a water management flow field. The bipolar plate includes at least one porous layer. A first side of the porous layer is fluidly connected to the water management flow field via a plurality of pores that act as a bubble barrier. An opposing second side of the porous layer includes either the fuel reactant flow field or the oxidant flow field. In one example, the dedicated coolant passage is internal to the bipolar plate, and may be configured to flow an antifreeze-type coolant.

Abstract: Disclosed are an antioxidant for fuel cells, a membrane electrode assembly including the same and a method for preparing the antioxidant. The antioxidant for fuel cells includes a core including at least one selected from the group consisting of a metal oxide (MxOk) and a complex metal oxide (MxNyOj, N and M being different metals), and an outer portion (e.g., a shell) located on or over a surface of the core and formed by performing reduction treatment of the surface of the core using a thiourea-based compound. The outer portion includes metal cations (M(x?n)+, n being a natural number of 1 or more) having a smaller oxidation number than a valency of the metal (M) of the core.

Abstract: To provide an electrolyte material having a low hydrogen gas permeability and excellent hot water resistance. An electrolyte material comprising a polymer having units represented by the following formula u1 and units based on chlorotrifluoroethylene at the specific proportion: wherein Q11 is a perfluoroalkylene group which may have an etheric oxygen atom, Q12 is a single bond or a perfluoroalkylene group which may have an etheric oxygen atom, Y1 is a fluorine atom or the like, s is 0 or 1, Rf1 is a perfluoroalkyl group which may have an etheric oxygen atom, X1 is an oxygen atom or the like, a is 0 when X1 is an oxygen, and Z+ is H+ or the like.

Abstract: The invention provides a dynamic seal test device for cryogenic fluid medium. The dynamic seal test device includes stator unit, rotor unit, slipway, servo motor unit and sensors. The tested seal is installed inside the stator, and the thermal insulation stator and vacuum rotor together form a dynamic seal test structure. The seals and shaft sleeves can be flexibly replaced, which is beneficial to study the influence of different seal types, structure, and seal land configurations on the sealing performance. The servo motor provides power for the rotor and controls the rotation speed. The device greatly improves the thermal insulation capacity to avoid the gasification for the cryogenic fluid medium induced by the heat transfer from environment so that ensuring the stability of the test device.

Abstract: A proton exchange membrane includes a porous structural framework and a boron-based acid group bonded to the porous structural framework. The porous structural framework may be formed of an amorphous or crystalline inorganic material and/or a synthetic or natural polymer. The boron-based acid group may be a tetravalent boric acid derivative, such as a cyclic boric acid derivative, borospiranic acid, or a borospiranic acid derivative. The boron-based acid group may be the reaction product of boric acid or a boric acid derivative and a poly-hydroxy compound.

Abstract: The invention provides a variety of novel devices, systems, and methods of utilizing mixed-ionic-electronic conductor (MIEC) materials adapted to function with an applied current or potential. The materials, as part of a circuit, are placed in contact with a part of a human or nonhuman animal body. A sodium selective membrane system utilizing the MIEC is also described.

Abstract: Provided are a fuel cell and a method for manufacturing the fuel cell capable of enhancing the joining (joint strength) with a resin sheet and contributing to reduction in the material cost and the product cost. A GDL (e.g., An-GDL) has a protrusion protruding to the outside of a MEA, and the resin sheet is bonded with the GDL at the protrusion of the GDL via the adhesive layer on the outside of the MEA.

Abstract: A fuel cell plate comprising a face intended to route a fuel gas or an oxidizing gas to the active surface of a Membrane Electrode Assembly, said face of the plate comprising projecting ribs delimiting a determined number of channels provided for the circulation of gas, the channels having a determined length (LCA) and a determined width (E), the ribs having a determined width (LA), the plate being characterized in that the product P of the total length (LN) of the ribs on the plate per unit of active surface (in cm2) multiplied by the rate of opening (TO) of the plate is between 4.7 and 10, i.e. that 4.7<P (cm?1)=LN×TO)/S<10, the rate of opening TO being defined by TO=100·(E/E+LA), the active surface of the plate being the surface of the plate intended to be facing the active surface of the Membrane Electrode Assembly.

Abstract: A catalyst layer (20) for a fuel cell and to a method suitable for producing the catalyst layer (20). The catalyst layer (20) includes a catalyst material (22) containing a catalytic material (24) and optionally porous carrier material (23) on which the catalytic material (24) is supported. The catalyst layer also includes mesoporous particles (21) made from hydrophobic material.

Abstract: A method for producing a fluorosulfonyl group-containing compound to obtain a compound represented by the following formula 5 from a compound represented by the following formula 1 as a starting material and a method for producing a fluorosulfonyl group-containing monomer in which the fluorosulfonyl group-containing compound is used: wherein R1 and R2 are a C1-3 alkylene group, and RF1 and RF2 are a C1-3 perfluoroalkylene group.

Abstract: To provide a metal-based structure or nanoparticles whose homogeneity is not deteriorated and whose sticking formation is easy, and a production method thereof with a high safety. A metal-based structure comprises a hydrogen compound, cluster, or an aggregate thereof, represented by the general formula: MmH. The M is a metal-based atom. The m is an integer of 3 or more and 300 or less. H is a hydrogen atom.

Abstract: A membrane catalyst layer assembly includes: a PEM; and a pair of catalyst layers disposed on main surfaces of the PEM. One of the pair of catalyst layers contains: mesoporous carbon with an average particle size of 100 nm or more, the mesoporous carbon having mesopores with a mode radius of 1-25 nm and a pore volume of 1.0-3.0 cm3/g; a catalytic metal; a proton-conducting resin; and at least one type of carbon particles with a smaller average particle size than the mesoporous carbon. The one of the pair of catalyst layers has a first surface layer which is adjacent to the PEM and contains the mesoporous carbon, and a second surface layer which is opposite the PEM and contains the mesoporous carbon, a volume percentage of the mesoporous carbon in the second surface layer is lower than a volume percentage of the mesoporous carbon in the first surface layer.

Abstract: A novel process for making PBI films starting from gel PBI membranes polymerized and casted in the PPA process wherein acid-imbibed gel PBIs are neutralized in a series of water baths and undergo controlled drying in association with a substrate material, yielding a PBI film without the use of organic solvents.

Abstract: A method for forming a caged electrocatalyst particles for fuel cell applications include a step of forming modified particles having a porous SiO2 shell on a surface of platinum-containing particles. The modified particles are subjected to acid treatment or electrochemical oxidation to remove a portion of the platinum-containing particle thereby creating caged electrocatalyst particles having a gap between the platinum-containing particles and their SiO2 shell.

Abstract: The disclosure relates to a self-charging device for energy harvesting and storage. The self-charging device for energy harvesting and storage includes a first electrode, a second electrode spaced from the first electrode, a solid electrolyte bridging the first electrode and the second electrode, and a water absorbing structure. The water absorbing structure is located on the second electrode, absorbs water from external environment and transmits the absorbed water to the solid electrolyte.

Abstract: A carbon catalyst, a battery electrode, and a battery, each exhibits excellent catalytic performance. A carbon catalyst contains two kinds of transition metals and has such a carbon structure that an interplanar spacing d002, which is determined from a Bragg angle of one of three diffraction peaks fbroad, fmiddle, and fnarrow obtained by separating a diffraction peak around a diffraction angle (2?) of 26° in an X-ray diffraction pattern of powder X-ray diffraction with a CuK? ray, the one diffraction peak being the diffraction peak fbroad, is 0.374 nm or more.

Abstract: A fuel cell stack and inspection method, the fuel cell stack including fuel cells disposed in a stack and interconnects disposed between the fuel cells. Each fuel cell includes an electrolyte, an anode disposed on a first side of the electrolyte, a cathode disposed on an opposing second side of an electrolyte, and a witness mark disposed on the first side of the electrolyte. Each interconnect includes first ribs disposed on air side of the interconnect and at least partially defining oxidant channels, and second ribs disposed on an opposing fuel side of the interconnect and at least partially defining fuel channels. The witness mark of each fuel cell is visible from outside of the stack when the cathode directly faces the air side of an adjacent interconnect.

Abstract: In an electrolyte membrane for a fuel cell, having nanofiber unwoven cloth buried in an electrolyte resin, the nanofiber unwoven cloth is disposed being exposed only from one face of the electrolyte membrane. The fuel cell includes a MEA having an anode electrode disposed on one face of the electrolyte membrane and having a cathode electrode disposed on the other face thereof, and a pair of separators holding the MEA by sandwiching the MEA therebetween. Thereby, the electrolyte membrane for a fuel cell, the manufacturing method of the electrolyte membrane, and the fuel cell are provided with which the electric power generation property and productivity are improved.

Abstract: A lamellar structure graphite foil is used as a material for a separator for a fuel cell, and a hydrophobic layer is formed by impregnation on flow-field channels of the graphite foil. Such a separator is manufactured by forming the flow field channel by etching the graphite foil formed with the mask pattern thereon and forming a hydrophobic layer by impregnation. According to such a separator, performance of a fuel cell stack is enhanced and the manufacturing process of a separator is simplified.

Abstract: The present invention relates to a self-humidifying ion-exchange composite membrane including an aromatic hydrocarbon polymer ion-exchange membrane formed on the surface of a porous polymer support and a thin hydrophobic coating layer having a nanocracked morphology pattern on the surface of the ion-exchange membrane. The self-humidifying ion-exchange composite membrane of the present invention has good thermal/chemical stability, high mechanical strength, high ion-exchange capacity, and good long-term operational stability. Particularly, the self-humidifying ion-exchange composite membrane of the present invention is able to self-hydrate even under high-temperature and low-humidity conditions. Due to these advantages, it is expected that the self-humidifying ion-exchange composite membrane of the present invention will be commercialized as an electrolyte membrane for a fuel cell or a membrane for water treatment.

Abstract: Provided is a method of manufacturing a separator for a fuel cell comprising: accumulating fibers obtained by electrospinning a spinning solution in which a polymer and a solvent are mixed to obtain a first support having first pores in a three-dimensional network structure; electrospraying a spraying solution in which a first ion exchange resin and a solvent are mixed to spray droplets of the first ion exchange resin on the first support body; accumulating fibers obtained by electrospinning a spinning solution in which a polymer and a solvent are mixed on the first support to form a second support having second pores in a three-dimensional network structure; and electrospraying a spraying solution in which a second ion exchange resin and a solvent are mixed to spray droplets of the second ion exchange resin on the second support body and fill the second ion exchange resin in the second pores.

Abstract: This application relates to an enclosure for a portable electronic device. The enclosure includes a titanium substrate having a textured surface that includes peaks separated by valleys, where the textured surface is characterized as having (i) an Sdq (root mean square gradient) that is greater than 0.2 micrometers, and (ii) a gloss value that is greater than 90 gloss units as measured at 60 degrees by a gloss meter.

Abstract: The present disclosure relates to a technique for manufacturing a humidifying membrane including a hydrophobic thin film-coating layer having a nano-sized crack morphology pattern on the surface of an aromatic hydrocarbon-based polymer ion exchange membrane and applying the membrane to a reverse electrodialysis process. The humidifying membrane including a hydrophobic thin film-coating layer having a nano-sized crack morphology pattern on the surface of an aromatic hydrocarbon-based polymer ion exchange membrane, manufactured according to the present disclosure, embodies a low bulk resistance of the ion exchange membrane and significantly improves ion selectivity, thereby overcoming the trade-off relationship between membrane resistance and ion selectivity, and thus may be commercially available as an anion and cation exchange membrane of a reverse electrodialysis device.

Abstract: A core-shell particle with a ceramic core and a hydrogel shell provided on a surface of the ceramic core, wherein the hydrogel shell is formed through polymerizing a monomer comprising a first compound having an ethylenically unsaturated group and a functional group capable of forming hydrogen bonds with water and a second compound having two or more ethylenically unsaturated groups and an inorganic element, a polymer electrolyte membrane including the core-shell particle, a fuel cell or an electrochemical cell including the polymer electrolyte membrane, and a method for preparing a core-shell particle.

Abstract: A composite solid electrolyte (100) for lithium batteries can include a solid polymer (110), phyllosilicate nanoparticles (120) distributed in the solid polymer, and a lithium salt (130) distributed in the solid polymer. In one example, the composite solid electrolyte can be used in a solid state lithium battery cell (400) made up of composite solid electrolyte, an anode (420) containing lithium in contact with a first surface of the composite solid electrolyte, and a cathode (430) in contact with a second surface of the composite solid electrolyte.

Abstract: A fuel cell having an anode-cathode stack includes at least one active surface layer formed by a first channel structure with a first and at least one second channel for conducting a first fluid over the at least one active surface layer of the anode-cathode stack. A first distributor structure for distributing the first fluid into the first and the at least one second channel of the channel structure is provided. The first distributor structure is configured with a first surface region assigned to the first channel and with a second surface region assigned to the second channel. The two surface regions are configured with a flow resistance of differing magnitude for the first fluid distributed in the first distributor structure.

Abstract: A fuel cell failure diagnostic apparatus is provided. The apparatus includes a water-level sensor that senses a water-level of water generated at an anode side of a fuel cell stack and stored in a water trap and a drain valve for the drain control of the generated water. A drain valve position sensor senses a position of the drain valve. A controller detects a failure situation by performing failure diagnosis based on the sensing information generated from the water-level sensor and the drain valve position sensor, and performs a corresponding control depending upon the failure situation.

Abstract: A fuel cell includes a membrane electrode assembly and a metal separator. The membrane electrode assembly includes an electrolyte membrane, first and second electrodes, and a resin frame member. The resin frame member is provided on an outer peripheral portion of the membrane electrode assembly. The metal separator is stacked on the membrane electrode assembly in a stacking direction and includes a reactant gas channel, a reactant gas manifold, and a flat portion. The resin frame member of the membrane electrode assembly has an outer shape to be disposed further inward than the reactant gas manifold and includes a connection channel portion that is disposed outward from an electrode surface and that connects the reactant gas manifold and the reactant gas channel to each other. The flat portion is provided in contact with the connection channel portion.

Abstract: A membrane thickness evaluation apparatus includes a first voltage application electrode and a second voltage application electrode. A membrane electrode assembly is interposed between the first voltage application electrode and a second voltage application electrode. Alternating current voltage is applied to the membrane electrode assembly to measure the impedance of an electrolyte membrane, and electrostatic capacitance is calculated from the impedance. The electrostatic capacitance is compared with the correlation with the membrane thickness to determine the membrane thickness of the electrolyte membrane.

Abstract: Biological material is used to build up biological cathode electrodes (biological cathode) and biological batteries, particularly biological metal air batteries as well as biological flow battery. A biological battery system includes a reaction vessel, a medium, a conductive anode and a biological cathode electrode. The biological cathode has a conductive support layer, a polymeric binding layer disposed between the conductive support layer and a contact layer. The contact layer being configured to be in electrical contact with biological components in the medium or being deposited with biological components. When the reaction vessel is open to an ambient air, the biological components accept electrons from the cathode.

Abstract: An electrode plate manufacturing apparatus includes: a first roll; a second roll that consolidates a particle aggregate and forms an undried active material film; and a third roll that transcribes the undried active material film on the second roll onto a current collector foil. A circumferential velocity A of the first roll, a circumferential velocity B of the second roll, a conveyance velocity C of the current collector foil, a contact angle ? of the first roll, a contact angle ? of the second roll, and a contact angle ? of the current collector foil satisfy conditions (i) ?????1.6×B/A+40 where ???>0 and B/A?1 and (ii) ?????1.6×C/B+40 where ???>0 and C/B?1.

Abstract: A dummy cell laminated on a fuel cell stack and configured not to perform power generation includes: a common appearance portion having an appearance common with an appearance of a power generation cell used in the fuel cell stack and configured to perform power generation; and a non-common appearance portion having an appearance different from the appearance of the power generation cell.

Abstract: An organic polymeric compound called a Furuta or para-Furuta polymer is characterized by polarizability and resistivity has repeating units of a general structural formula: P1 may be acrylate, methacrylate, polypropylene, polyethylene, polyamide, polyaramid, polyester, siloxane, or polyethylene terephthalate. Tail is a resistive substitute. L is a linker group attached to an ionic functional group Q; j, a number of ionic functional groups Q, ranges from 1 to 5; n and m independently range from 3 to about 1000. Q is an ionic liquid ion, zwitterion, or polymeric acid. The number t ranges from 6 to 200,000. B is a counter ion, that can supply an opposite charge to balance a charge of the organic polymeric compound; s is a number of counter ions B. A plasticizer increases mobility of the polymers within the compound.

Abstract: The present invention provides a novel and improved metal-air battery in which a lot of catalyst can be disposed in a triple phase boundary, and further, battery properties can be improved. In the metal-air battery according to the present invention, a catalyst layer of an air electrode of a metal-air battery contains a catalyst element and a carbon material, the carbon material comprises two materials of a carbon material A supporting thereon the catalyst element and a carbon material B not supporting the catalyst element, the catalyst layer comprises an agglomerate X containing the catalyst element, the carbon material A and the carbon material B as main components and an agglomerate Y containing the carbon material B as a main component, and the agglomerate X is a continuum and the agglomerate Y is dispersed in the agglomerate X.

Abstract: To provide methods for producing a liquid composition, a coating liquid for a catalyst layer and a membrane electrode assembly, capable of making cracking less likely to occur at the time of forming a solid polymer electrolyte membrane or a catalyst layer. A copolymer having a structural unit represented by —[CF2—CF{(OCF2CFX)mOp(CF2)nSO3H}]— (wherein X: F or CF3, m: 1 to 3, p: 0 or 1, and n: an integer of 1 to 12) and a structural unit derived from tetrafluoroethylene, is dispersed in a medium containing water and a hydrocarbon-type alcohol (but not including a fluorinated solvent) to prepare a dispersion wherein the concentration of the copolymer is from 13 to 26 mass %, and the dispersion and a fluorinated solvent are mixed so that the sum of the concentration of the copolymer and the concentration of the fluorinated solvent becomes to be from 17 to 35 mass %, to prepare a liquid composition.

Abstract: The present invention provides a film for attaching a nanostructured material to a surface of a substrate, comprising: (a) a removable support; (b) an attaching layer for attaching the film to the surface of a substrate; and (c) the material directly coupled to the support and the attaching layer. Methods for making the film, methods for attaching the material to the surface of a substrate are also provided. The present invention further provides a surface having a material attached thereto by means of the attaching layer. Using the methods disclosed herein, a material having a high specific surface area (SSA) and having particular proper ties (e.g. super-hydrophobicity) can be applied to a substrate including a fuel cell, a conductive electrode, a dye sensitized solar cell, a diffuse reflective mirror, eyewear, a window and a vehicle (e.g. car) windscreen, for example to provide a self-cleaning surface.

Abstract: An ion-exchange membrane is disclosed here including ion-permeable layers impregnated with an ion-exchange material and arranged in an order from one face of the membrane to the opposite face of the membrane such that opposing layers in the supporting membrane substrate provide sufficiently identical physical properties to substantially avoid irregular expansion when in a salt solution. The ion-permeable layers including at least one non-woven layer and at least one reinforcing layer.