Disclosed is a composite electrolyte membrane comprising a microporous polymer substrate and a sulfonated polymer electrolyte. The composite electrolyte membrane comprises: a first polymer electrolyte layer formed of a first non-fluorinated or partially-fluorinated sulfonated polymer electrolyte; a non-fluorinated or partially-fluorinated microporous polymer substrate stacked on the first polymer electrolyte layer, wherein pores of the microporous polymer substrate are impregnated with a second non-fluorinated or partially-fluorinated sulfonated polymer electrolyte, and the first polymer electrolyte and the second polymer electrolyte are entangled with each other on an interface thereof; and a third polymer electrolyte layer formed on the microporous polymer substrate impregnated with the second polymer electrolyte by a third non-fluorinated or partially-fluorinated sulfonated polymer electrolyte, wherein the second polymer electrolyte and the third polymer electrolyte are entangled with each other on an interface thereof. A method for manufacturing the composite electrolyte membrane, and a membrane-electrode assembly (MEA) and a fuel cell comprising the composite electrolyte membrane are also disclosed.

A method of manufacturing an ion-conducting membrane. comprising the steps of: (a) providing a substrate; (b) depositing a first dispersion onto the substrate to form a first layer, wherein the first dispersion comprises an ion-conducting polymer; (c) depositing a second dispersion onto the first dispersion to form a second layer on the first layer, wherein the second dispersion comprises an ion-conducting polymer; (d) providing a reinforcing component comprising pores so that the second dispersion impregnates at least some of the pores of the reinforcing component; and (e) drying the first and second layers, wherein step (e) is performed after steps (c) and (d).

A method of manufacturing an ion-conducting membrane. comprising the steps of: (a) providing a substrate; (b) depositing a first dispersion onto the substrate to form a first layer, wherein the first dispersion comprises an ion-conducting polymer; (c) depositing a second dispersion onto the first dispersion to form a second layer on the first layer, wherein the second dispersion comprises an ion-conducting polymer; (d) providing a reinforcing component comprising pores so that the second dispersion impregnates at least some of the pores of the reinforcing component; and (e) drying the first and second layers, wherein step (e) is performed after steps (c) and (d).

An object of the present invention is to provide an electrode assembly for water electrolysis, in which an electrolyte membrane is kept from being deteriorated. The present invention provides an electrode structure for water electrolysis, including an anode electrode and a cathode electrode disposed to face each other, characterized in that at least one of the anode electrode and the cathode electrode includes a porous component and a reticular component in order from the facing surface side, and the standard deviation of a pressure distribution at the surface of contact between the anode electrode and the cathode electrode, determined by the following measurement method, is 2.7 MPa or less.

<Measurement Method>

After a test piece that has a pressure measurement film sandwiched between the anode electrode and the cathode electrode is pressurized at 4 MPa for 2 minutes, the pressure distribution obtained by a pressure analysis from a color image of the pressure measurement film, obtained from a pressure image analysis system, is defined as a pressure distribution at the surface of contact between the anode electrode and the cathode electrode, and the standard deviation of the pressure distribution is determined.

A composite electrolyte membrane having a composite layer that is a composite of a hydrocarbon polymer electrolyte and a fluorine-containing polymer porous substrate, wherein a fractal dimension D exhibiting the distribution of the hydrocarbon polymer electrolyte and the fluorine-containing polymer porous substrate in the composite layer is 1.7 or more. An object of the present invention is to enable a composite electrolyte membrane composed of a hydrocarbon polymer electrolyte and a fluorine-containing polymer porous substrate to achieve high proton conduction ability and high mechanical durability.

A composite electrolyte membrane having a composite layer that is a composite of a hydrocarbon polymer electrolyte and a fluorine-containing polymer porous substrate, wherein a fractal dimension D exhibiting the distribution of the hydrocarbon polymer electrolyte and the fluorine-containing polymer porous substrate in the composite layer is 1.7 or more. An object of the present invention is to enable a composite electrolyte membrane composed of a hydrocarbon polymer electrolyte and a fluorine-containing polymer porous substrate to achieve high proton conduction ability and high mechanical durability.

Disclosed are: a polymer electrolyte membrane which can guarantee the production of a membrane-electrode assembly having excellent mechanical properties without a decrease in performance, such as in ionic conductivity, and thus having a high enough durability to achieve at least 30,000 wet/dry cycles as measured according to the NEDO protocol; a membrane-electrode assembly including the polymer electrolyte membrane; and a method for measuring the durability of the membrane-electrode assembly. The polymer electrolyte membrane according to the present invention comprises a composite layer including: a porous support having multiple pores; and ionomers filling the pores, and has an MD internal tearing strength of 150 N/mm or greater, a TD internal tearing strength of 150 N/mm or greater, a stab initial strain of 8% or less, and a stab final strain of 10% or less.

Disclosed are: a polymer electrolyte membrane which can guarantee the production of a membrane-electrode assembly having excellent mechanical properties without a decrease in performance, such as in ionic conductivity, and thus having a high enough durability to achieve at least 30,000 wet/dry cycles as measured according to the NEDO protocol; a membrane-electrode assembly including the polymer electrolyte membrane; and a method for measuring the durability of the membrane-electrode assembly. The polymer electrolyte membrane according to the present invention comprises a composite layer including: a porous support having multiple pores; and ionomers filling the pores, and has an MD internal tearing strength of 150 N/mm or greater, a TD internal tearing strength of 150 N/mm or greater, a stab initial strain of 8% or less, and a stab final strain of 10% or less.

Disclosed are fuel cell systems, reinforced membrane electrode assemblies, and methods for fabricating a reinforced membrane electrode assembly. In an example, a disclosed method includes depositing an electrode ink onto a first substrate to form a first electrode layer, and applying a first porous reinforcement layer onto a surface of the first electrode layer to form a first catalyst coated substrate. The method also includes depositing a first ionomer solution onto the first catalyst coated substrate to form a first ionomer layer. A membrane porous reinforcement layer is applied onto a surface of the first ionomer layer to form a reinforced membrane layer.

Disclosed are fuel cell systems, reinforced membrane electrode assemblies, and methods for fabricating a reinforced membrane electrode assembly. In an example, a disclosed method includes depositing an electrode ink onto a first substrate to form a first electrode layer, and applying a first porous reinforcement layer onto a surface of the first electrode layer to form a first catalyst coated substrate. The method also includes depositing a first ionomer solution onto the first catalyst coated substrate to form a first ionomer layer. A membrane porous reinforcement layer is applied onto a surface of the first ionomer layer to form a reinforced membrane layer.