Disclosed is a method for manufacturing a stainless steel for a polymer electrolyte membrane fuel cell separator, and more particularly, a method for manufacturing a stainless steel for a polymer electrolyte membrane fuel cell separator capable of obtaining low contact resistance and high corrosion resistance by effectively removing a non-conductive coating and forming a new coating. According to an embodiment, the disclosed method for manufacturing a stainless steel for a polymer electrolyte membrane fuel cell separator includes performing alternating current electrolysis by immersing, in a sulfuric acid solution, a stainless steel having a passivation coating formed on a surface thereof by cold rolling and bright annealing, wherein the alternating current electrolysis is performed by applying a current density of 10 to 30 A/dm.sup.2.

The present disclosure relates to a membrane-electrode assembly for fuel cells and a method of manufacturing the same, and more particularly to a membrane-electrode assembly to which an electrolyte membrane including a cerium oxide and phosphoric acid functionalized graphene oxide is applied, whereby chemical durability and proton conductivity of the membrane-electrode assembly are improved.

Provided is a porous electrode substrate capable of reducing a drop in electromotive force when used in a battery. This porous electrode substrate comprises a carbon fiber sheet wherein carbon fibers are bound by a binder. For dust of 0.3 μm or more in particle size, the dust generation amount per 1 m.sup.2 of the porous electrode substrate is 120,000/m.sup.2 or less, as determined by the following method: dust particles in a gas obtained by suctioning at 47.2 mL/s for 40 minutes using a dust collecting hood having an opening of 500 mm×100 mm while traveling the sheet at a speed of 10 m/min from a position 200 mm below the sheet are used; the number of dust particles having a diameter within a predetermined range is measured by a particle counter; and the measured value is divided by 200 m.sup.2, which is a suction area, and the resulting value is defined as a dust generation amount per 1 m.sup.2.

Poly(aryl piperidinium) polymers with pendant cationic groups are provided which have an alkaline-stable cation, piperidinium, introduced into a rigid aromatic polymer backbone free of ether bonds. Hydroxide exchange membranes or hydroxide exchange ionomers formed from these polymers exhibit superior chemical stability, hydroxide conductivity, decreased water uptake, good solubility in selected solvents, and improved mechanical properties in an ambient dry state as compared to conventional hydroxide exchange membranes or ionomers. Hydroxide exchange membrane fuel cells comprising the poly(aryl piperidinium) polymers with pendant cationic groups exhibit enhanced performance and durability at relatively high temperatures.

Poly(aryl piperidinium) polymers with pendant cationic groups are provided which have an alkaline-stable cation, piperidinium, introduced into a rigid aromatic polymer backbone free of ether bonds. Hydroxide exchange membranes or hydroxide exchange ionomers formed from these polymers exhibit superior chemical stability, hydroxide conductivity, decreased water uptake, good solubility in selected solvents, and improved mechanical properties in an ambient dry state as compared to conventional hydroxide exchange membranes or ionomers. Hydroxide exchange membrane fuel cells comprising the poly(aryl piperidinium) polymers with pendant cationic groups exhibit enhanced performance and durability at relatively high temperatures.

Described herein is a polymer-electrolyte-membrane fuel cell (PEMFC) that incorporates a shunt into the membrane separator that becomes electronically conductive around a well-defined anodic onset potential, thereby preventing excessive anodic potentials at the positive electrode that would otherwise drive deleterious parasitic reactions such as catalyst dissolution or catalyst and carbon oxidation.

A fuel battery includes a membrane-electrode assembly including a first catalyst layer and a first gas diffusion layer stacked on a first surface of a polymer electrolyte membrane, and a second catalyst layer and a second gas diffusion layer stacked on a second surface of the polymer electrolyte membrane. The membrane-electrode assembly is interposed between a first separator and a second separator. The first separator includes a rib and a groove on a surface that is in contact with the first gas diffusion layer, the rib and the groove defining a gas flow path through which a reaction gas is to flow. A thickness of the first gas diffusion layer is defined as h, and a width of a portion of the rib that is in contact with the first gas diffusion layer is defined as Rw such that 0.29 Rw≤h≤0.55 Rw is satisfied.

A membrane-electrode assembly including a catalyst layer that includes a catalyst-supporting carrier in which a catalyst is supported on a carrier made of an inorganic oxide, and a highly hydrophobic substance having a higher degree of hydrophobicity than the inorganic oxide, the catalyst layer being formed on at least one surface of a polymer electrolyte membrane. It is preferable that, in the membrane-electrode assembly, the degree of hydrophobicity of the highly hydrophobic substance is from 0.5 vol % to 45 vol % at 25° C., the degree of hydrophobicity being defined as a concentration of methanol (vol %) when a light transmittance of a dispersion obtained by dispersing the highly hydrophobic substance in a mixed solution of water and methanol reaches 80%.

Fuel cell system with a combined fuel evaporation and cathode gas heater unit, and its method of operation A fuel cell system, in which the cathode gas heater and the evaporator are combined in a single compact first heat exchange unit which includes a first housing inside which thermal energy is transferred from the first coolant to both the cathode gas and the fuel.

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.