Abstract: A catalyst complex for fuel cells and a method for manufacturing an electrode including the same are disclosed. The catalyst complex for fuel cells, which is included in an electrode for fuel cells, includes a first catalyst configured to cause hydrogen oxidation reaction (HOR) and a second catalyst configured to cause water electrolysis reaction, i.e., oxygen evolution reaction (OER). The outer surface of the first catalyst is coated with a first ionomer binder, the outer surface of the second catalyst is coated with a second ionomer binder, and an equivalent weight (EW) of the second ionomer binder differs from an equivalent weight (EW) of the first ionomer binder.

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: Disclosed are an electrolyte membrane with improved ion conductivity and enhanced water transport and a method for manufacturing the same. The electrolyte membrane includes an ion transport layer including an ionomer having proton conductivity and a catalyst dispersed in the ion transport layer, and the catalyst includes a support including a shell configured to have a designated shape and size and to be hollow and at least one hole configured to allow an inner space to communicate with an outside therethrough, and a metal supported on the support.

Abstract: Disclosed are an electrolyte membrane for fuel cells that can prevent poisoning of catalysts and a method of producing the same. The electrolyte membrane for fuel cells includes an ion transport layer including an ionomer having proton conductivity, and a catalytic composite dispersed in the ion transport layer, wherein the catalytic composite includes a catalytic particle including a catalytic metal component having an activity of decomposing hydrogen peroxide, and a protective layer formed on at least a part of a surface of the catalytic particle to prevent the ionomer from contacting the catalytic metal component.

Abstract: Disclosed is an antioxidant for an electrolyte membrane of fuel cells. The antioxidant may include a support including silicon dioxide and having a nanotube shape, and a metal oxide supported on the support.

Abstract: Disclosed are a membrane electrode assembly with a sub-gasket and a manufacturing method thereof. The membrane electrode assembly includes an electrolyte membrane, the sub-gasket formed in an edge region of the electrolyte membrane to surround a central region of the electrolyte membrane, and an adhesive layer formed between the electrolyte membrane and the sub-gasket and including an adhesive material and an antioxidant. The electrolyte membrane is formed to have a flat surface in a first direction, the sub-gasket extends in the first direction and a second direction vertical to the first direction, and the antioxidant includes a metal salt hydrate.

Abstract: Disclosed is a method of manufacturing an electrolyte membrane for fuel cells. The method includes preparing an electrolyte layer including one or more ion conductive polymers that form a proton movement channel, and permeating a gas from a first surface of the electrolyte layer to a second surface of the electrolyte layer.

Abstract: The present disclosure to an electrolyte membrane containing a polyfluorene-based ionomer, and more particularly, to an electrolyte membrane containing a polyfluorene-based ionomer which has a fluorene main chain composed of only a carbon-carbon bond and a side chain composed of a perfluorosulfonic acid group. The electrolyte membrane containing the polyfluorene-based ionomer has high proton conductivity, excellent chemical durability, excellent mechanical property, and excellent volume stability.

Abstract: A fuel cell system capable of improving the chemical durability of a membrane electrode assembly by compensating for the amount of an antioxidant lost within the electrolyte membrane or electrode of the fuel cell stack in such a manner that the antioxidant is provided from an antioxidant supply device, provided in a fuel processing system and/or an air processing system, to a fuel cell stack, in preparation for a case where the antioxidant within the electrolyte membrane or electrode is lost due to the dissolution or migration characteristic of the antioxidant.

Abstract: Disclosed is a method of manufacturing an electrolyte membrane including an antioxidant. The method may include forming a first dispersion liquid including deionized water, a first ionomer dispersion solution and an antioxidant, and forming a second dispersion liquid including the first dispersion liquid and a second ionomer dispersion solution.

Abstract: Disclosed are an electrode for a fuel cell a membrane-electrode assembly including the same, and a method of preparing the same. The electrode may include catalyst particles; and a binder in which the catalyst particles are dispersed. In particular, the binder may include an ionomer having proton conductivity and a polymer of intrinsic microporosity (PIM) in order to implement high oxygen permeability.

Abstract: Disclosed is an electrolyte membrane for a membrane-electrode assembly, which may include a filler that is a polymer compound (oligomer) having a low molecular weight. The electrolyte membrane may suitably include an oligomeric poly(vinylpyrrolidone) compound including a sulfonic acid group. The electrolyte membrane for a membrane-electrode assembly may have improved proton conductivity.

Abstract: A water electrolysis system includes a water electrolytic stack, a water reservoir connected to the water electrolytic stack to supply water to the water electrolytic stack, a water circulation pump supplying the water in the water reservoir to the electrolytic stack; and a control unit configured to, during an operation stoppage of the electrolysis system, control the driving of the water circulation pump to convert the water in the electrolytic stack from an acidic condition to a neutral condition and to regulate a unit cell voltage of the electrolytic stack to a voltage such that an electrolysis reaction does not occur and a chemical state of an anode catalyst is stably maintained.

Abstract: Disclosed are a membrane-electrode assembly for fuel cells and a method of manufacturing the same. The membrane-electrode assembly for fuel cells may include an electrolyte membrane including a phosphonic acid functionalized graphene oxide in order to improve the mechanical strength and proton conductivity thereof and a method of manufacturing the same.

Abstract: Disclosed are a catalyst composite for a fuel cell and a method of manufacturing the same. The catalyst composite includes a support containing carbon (C), a metal catalyst supported on the support, and an ionomer binder coated on the surface of the support and on the surface of the metal catalyst. The ionomer binder coated on the surface of the metal catalyst is formed so as to be thinner than the ionomer binder coated on the surface of the support.

Abstract: Disclosed are a polymer electrolyte membrane for a fuel cell, a membrane-electrode assembly including the same, a fuel cell and a method of manufacturing the polymer electrolyte membrane for a fuel cell. Particularly, the polymer electrolyte membrane for a fuel cell may include ionomer layers including a voltage reversal tolerance-increasing additive including a water electrolysis catalyst and an electrical conductor and provided on a porous reinforced film.

Abstract: Disclosed are a method for manufacturing a polymer electrolyte membrane for fuel cells in which a plurality of porous reinforcement films and ionomer layers are continuously disposed or stacked, and a polymer electrolyte membrane for fuel cells manufactured thereby. The polymer electrolyte membrane for fuel cells includes the porous reinforcement films, thus having excellent mechanical stiffness and improved physical durability. Further, the polymer electrolyte membrane for fuel cells includes an ionomer layer including a catalyst for decomposing peroxide configured to block gas crossover and may thus minimize performance degradation due to gas crossover and prevent an electrical short, and the polymer electrolyte membrane for fuel cells makes it easy to adjust the position of the ionomer layer in the electrolyte membrane in the thickness direction and may thus effectively mitigate gas crossover.

Abstract: Disclosed are an antioxidant for a fuel cell having a high degree of dispersion and/or distribution and excellent antioxidant capability and a membrane-electrode assembly including the same. The antioxidant includes a metal oxide and a sulfur- containing organic compound, for example, an organic compound including a sulfinic acid anion group (R—SO2?), adsorbed on the metal oxide.

Abstract: Disclosed is an electrolyte membrane for fuel cells including a catalytic composite including a catalytic particle coated with an oxygen-permeable material and a method of producing the same. The electrolyte membrane for fuel cells includes an ion transport layer including an ionomer having proton conductivity and a catalytic composite dispersed in the ion transport layer, and the catalytic composite includes a catalytic particle including a catalytic metal component having activity of decomposing hydrogen peroxide and a coating layer formed on at least a part of a surface of the catalytic particle and including an oxygen-permeable material.

Abstract: Disclosed are an electrolyte membrane for fuel cells that can prevent poisoning of catalysts and a method of producing the same. The electrolyte membrane for fuel cells includes an ion transport layer including an ionomer having proton conductivity, and a catalytic composite dispersed in the ion transport layer, wherein the catalytic composite includes a catalytic particle including a catalytic metal component having an activity of decomposing hydrogen peroxide, and a protective layer formed on at least a part of a surface of the catalytic particle to prevent the ionomer from contacting the catalytic metal component.