The present invention relates to an electrode comprising organic functional metal oxides, a manufacturing method thereof, a membrane-electrode assembly including the same, and a fuel cell including the membrane-electrode assembly, and the electrode comprises a support, catalyst particles supported on the support, organic functional metal oxide nanoparticles supported on the support, and an ionomer positioned on the surface of the support. The electrode improves catalyst performance and durability in a high voltage range, can reduce the amount of a catalyst used and catalyst costs by enabling excellent current density and power density to be obtained even in a state that a relatively small amount of the catalyst is used through an increase in catalyst utilization and uniform dispersion of the catalyst, and improves performance in general and low humidification conditions.

A composite including an electrolyte layer containing solid oxide, and at least one electrode selected from a cathode disposed on one side of the electrolyte layer in a first direction and an anode disposed on the other side of the electrolyte layer in the first direction. Either one of two surfaces of the composite located on opposite sides in the first direction satisfies a first requirement that, as viewed in the first direction, a curvature determined on the basis of any three points juxtaposed at intervals of 5 mm is less than 0.0013 (l/mm) and that, as viewed in a second direction perpendicular to the first direction, the curvature is the reciprocal of the radius of an imaginary circle passing through the any three points.

An anode catalyst layer for a fuel cell according to the present invention includes: electrode catalyst particles; a carbon carrier carrying the electrode catalyst particles; water electrolysis catalyst particles; a proton-conductive binder; and a graphitized carbon, wherein the content of graphitized carbon in the anode catalyst layer for a fuel cell is 15-70 volume % with respect to the total volume of the electrode catalyst particles, the carbon carrier, and the graphitized carbon.

A catalyst having an excellent oxygen reduction catalytic ability, and showing excellent durability when used for an electrode for fuel cells and metal-air batteries; and a production method of a catalyst having an excellent oxygen reduction catalytic ability, and showing excellent durability when used for an electrode for fuel cells and metal-air batteries are provided. The production method of a catalyst includes: a step (a) of dissolving a metal complex in a solvent to prepare a solution; a step (b) of dispersing a conductive powder in the solution to prepare a dispersion liquid; and a step (c) of removing the solvent from the dispersion liquid, in which a complex is formed by adsorbing the metal complex on a surface of the conductive powder to use the complex as a catalyst.

A catalyst ink which can be directly applied to a polymer electrolyte membrane without producing wrinkles or cracks in the catalyst layer and without lowering performance, and a membrane electrode assembly using the catalyst ink. The catalyst ink for an electrode catalyst layer includes a solvent. The solvent contains catalyst-supported carbon particles which are carbon particles supporting a catalyst, a polymer electrolyte, and at least one of carbon fibers and organic electrolyte fibers. The solvent has a particle size distribution which a first peak lies in a range of 0.1 μm or more and 1 μm or less, and a second peak lies in a range of 1 μm or more and 10 μm or less. The catalyst ink is directly applied to a polymer electrolyte membrane to produce a membrane electrode assembly.

The porphyrin-based catalysts for water splitting are composites of porphyrin or metalloporphyrin active ingredients, conductive carbon (e.g., graphene sheets, vapor grown carbon fiber, carbon black, etc.), and a polymer or binder that may be coated on a glassy carbon electrode. The polymer or binder may be Nafion oil or polyvinylidine difluoride. The porphyrin may be a porphyrin having a transition metal or hydrogen at its center, and may be halogenated and/or have a thiophene substituent.

A redox flow battery may include: a membrane interposed between a first electrode positioned at a first side of the membrane and a second electrode positioned at a second side of the membrane opposite to the first side; a first flow field plate comprising a plurality of positive flow field ribs, each of the plurality of positive flow field ribs contacting the first electrode at first supporting regions on the first side; and the second electrode, including an electrode spacer positioned between the membrane and a second flow field plate, the electrode spacer comprising a plurality of main ribs, each of the plurality of main ribs contacting the second flow field plate at second supporting regions on the second side, each of the second supporting regions aligned opposite to one of the plurality of first supporting regions. As such, a current density distribution at a plating surface may be reduced.

The present invention relates to a method for producing a membrane for a fuel cell or electrolytic cell, in which (i) a liquid coating composition, which contains a supported catalyst containing precious metal and also contains an ionomer, is applied to a polymer electrolyte membrane which contains an ionomer, the ionomer of the liquid coating composition and the ionomer of the polymer electrolyte membrane each being a copolymer which contains as monomer a fluoroethylene and a fluorovinyl ether containing a sulfonic acid group, (ii) the coated polymer electrolyte membrane is heated to a temperature in the range from 178° C. to 250° C.

A single fuel cell according to the present disclosure includes a power generation section, a power non-generation section which does not include the power generation section, and an oxygen-ion-insulating gas seal film arranged so as to cover the surface of the power non-generation section, and the gas seal film is configured by a structure formed by firing a material containing MTiO.sub.3 (M: alkaline earth metal element) and metal oxide. The structure may include a first structure and a second structure which are different in composition, the first structure may include components derived from MTiO.sub.3 in larger amounts than the second structure, the second structure may include a metal element contained in the metal oxide in a larger amount than the first structure, and the area ratio of the second structure in the structure may be not less than 1% and not more than 50%.

A fuel cell cathode catalyst layer structure for enhancing the durability of a catalyst is provided. The cathode catalyst layer structure includes a first catalyst portion, a second catalyst portion, and a third catalyst portion that are arranged in sequence from an area close to a diffusion layer to an area close to a proton exchange membrane (PEM); a pure platinum catalyst is placed inside the first catalyst portion, the second catalyst portion, and the third catalyst portion; platinum loads of the pure platinum catalysts inside the first catalyst portion, the second catalyst portion, and the third catalyst portion decrease progressively; and average particle sizes of pure platinum catalyst particles inside the first catalyst portion, the second catalyst portion, and the third catalyst portion increase progressively. The pure platinum catalyst with a large or small particle size is more resistant to corrosion, and improves the initial performance of fuel cell.