A gas-diffusion electrode substrate includes an electrode substrate and a microporous layer (MPL) disposed on one surface of the electrode substrate, wherein the gas-diffusion electrode substrate has a thickness of 110 m or more and 240 m or less, and where a cross section of the gas-diffusion electrode substrate is divided into a part having the MPL and a part having no MPL, and the part having no MPL is further equally divided into a part (CP1 cross section) in contact with the MPL and a part (CP2 cross section) not in contact with the MPL, the CP1 cross section has an F/C ratio of 0.03 or more and 0.10 or less and the CP2 cross section has an F/C ratio less than 0.03, wherein F is a mass of a fluorine atom, and C is a mass of a carbon atom.

Disclosed is a membrane-electrode assembly having increased active area, improved fluid management capability, and decreased gas transfer resistance due to electrodes having patterned structures on both sides. Also disclosed are a method for manufacturing same, and a fuel cell comprising same. A membrane-electrode assembly according to the present invention comprises: a first electrode; a second electrode; and a polymer electrolyte membrane between the first and second electrodes, wherein the first electrode has a first surface facing the polymer electrolyte membrane and a second surface opposite the first surface, the first surface having a first patterned structure, and the second surface having a second patterned structure.

In the case in which a fuel cell has a structure in which a cathode (2) and an anode (1) are opposed with the intermediary of an electrolyte layer (3) and the cathode (2) is formed of an electrode to which an oxygen reductase and so on is immobilized and this electrode has pores inside, at least part of the surface of this electrode is rendered water repellent. For example, the surface of the electrode is rendered water repellent by forming a water-repellent agent on the surface of this electrode. Thereby, in the case in which the cathode is formed of an electrode to which an enzyme is immobilized and this electrode has pores inside, a fuel cell that can stably achieve a high current value by optimization of the amount of water contained in the cathode and a manufacturing method thereof are provided.

One embodiment includes a method comprising the steps of providing a first dry catalyst coated gas diffusion media layer, depositing a wet first proton exchange membrane layer over the first catalyst coated gas diffusion media layer to form a first proton exchange membrane layer; providing a second dry catalyst coated gas diffusion media layer; contacting the second dry catalyst coated gas diffusion media layer with the first proton exchange membrane layer; and hot pressing together the first and second dry catalyst coated gas diffusion media layers with the wet proton exchange membrane layer therebetween.

A hot-rolled austenitic iron/carbon/manganese steel sheet is provided. The strength of which is greater than 900 MPa, the product (strength (in MPa)elongation at fracture (in %)) of which is greater than 45000 and the chemical composition of which includes, the contents being expressed by weight 0.5%C0.7%, 17%Mn24%, Si3%, Al0.050%, S0.030%, P0.080% and N0.1%. A remainder of the composition includes iron and inevitable impurities resulting from the smelting. A recrystallized fraction of the structure of the steel is greater than 75%, a surface fraction of precipitated carbides of the steel is less than 1.5% and a mean grain size of the steel is less than 18 microns. A reinforcing element is also provided.

A reinforced catalyst layer assembly, suitably for use in a fuel cell, said reinforced catalyst layer assembly comprising: (i) a planar reinforcing component consisting of a porous material having pores extending through the thickness of the material in the z-direction, and (ii) a first catalyst component comprising a first catalyst material and a first ion-conducting material,
characterised in that the first catalyst component is at least partially embedded within the planar reinforcing component, forming a first catalyst layer having a first surface and a second surface is disclosed.

A manufacturing process includes: depositing a catalyst support on a gas diffusion layer to form a catalyst support-coated gas diffusion layer; depositing a catalyst on the catalyst support-coated gas diffusion layer to form a catalyst-coated gas diffusion layer; and depositing an ionomer on the catalyst-coated gas diffusion layer to form an ionomer-coated gas diffusion layer. A membrane electrode assembly for a fuel cell includes: a gas diffusion layer; a polymer electrolyte membrane; and a catalyst layer disposed between the gas diffusion layer and the polymer electrolyte membrane, wherein the catalyst layer includes an ionomer, and a concentration of the ionomer varies within the catalyst layer according to a concentration profile.

According to the present invention, there is provided a method of manufacturing a catalyst-coated ion-conducting membrane, the method comprising the steps of: (a) providing a catalyst layer on a backing layer, wherein the catalyst layer comprises pores; (b) applying a wetting solution to the catalyst layer, wherein the wetting solution impregnates at least some of the pores of the catalyst layer so as to form a wetted catalyst surface; (c) depositing a first dispersion onto the wetted catalyst surface to form a first dispersion layer on the wetted catalyst surface, wherein the first dispersion comprises an ion-conducting polymer; and (d) drying the first dispersion layer and the wetted catalyst surface after step (c).

A method for producing a carbon nanomaterial for use as a catalyst, including the steps of: (a) providing a precursor which is a source of lignin, (b) heating the precursor to an activation temperature from 700 C. to 800 C. in the presence of an alkali solution in order to produce an activated precursor, and (c) reacting the activated precursor with a source of nitrogen atoms in order to dope the activated precursor with nitrogen atoms, wherein the precursor is heated in step (b) to the activation temperature at a rate of at least 500 C. per minute.

A catalyst layer is provided herein that includes a catalyst support having positively charged surfaces, nanoparticles on the surfaces of the catalyst support, and negatively-charged ionomer films on the catalyst support and the nanoparticles thereon. The ionomer films may be formed on the catalyst support to be substantially uniform, conformal and thin by controlling electrostatic charge of the surfaces of the catalyst support, for example by utilizing electrostatic charge attraction between positively charged surfaces of the catalyst support and negatively-charged ionomer films. The catalyst layer may be incorporated into a membrane electrode assembly, a polymer electrolyte membrane fuel cell, and myriad other applications and uses.