Provided are an electrode catalyst layer, a membrane electrode assembly and a polymer electrolyte fuel cell, having sufficient drainage property and gas diffusibility with high power generation performance over a long term. An electrode catalyst layer (10) bonded to a surface of a polymer electrolyte membrane (11) includes at least a catalyst substance (12), a conductive carrier (13), a polymer electrolyte (14) and fibrous substances (15). The number of the fibrous substances (15) in which inclination θ of axes with respect to a surface of the electrode catalyst layer (10) bonded to the surface of the polymer electrolyte membrane (11) is 0°≤θ<45°, among the fibrous substances (15), is greater than 50% of the total number of the fibrous substances (15) contained.

The copolymer includes divalent units represented by formula —[CF.sub.2—CF.sub.2]—, at least one divalent unit represented by formula (I): and at least one divalent unit independently represented by formula (II): A is —N(RF.sup.a).sub.2 or a is non-aromatic, 5- to 8-membered, perfluorinated ring comprising one or two nitrogen atoms in the ring and optionally comprising at least one oxygen atom in the ring, each RFa is independently linear or branched perfluoroalkyl having 1 to 8 carbon atoms and optionally interrupted by at least one catenated O or N atom, each Y is independently —H or —F, with the proviso that one Y may be —CF.sub.3, h is 0, 1, or 2, each i is independently 2 to 8, and j is 0, 1, or 2. A catalyst ink and polymer electrolyte membrane including the copolymer are also provided.

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Disclosed are: a membrane-electrode assembly having enhanced adhesion and interfacial durability between a polymer electrolyte membrane and electrodes; and a method for manufacturing a membrane-electrode assembly, in which, in forming electrodes by directly coating a catalyst slurry on a polymer electrolyte membrane, adhesion and interfacial durability between the polymer electrolyte membrane and the electrodes can be enhanced without a separate additional step, thus improving both the durability and the productivity of the membrane-electrode assembly. The method comprises the steps of: dispersing a catalyst and an ion conductor in a dispersion medium to obtain a catalyst slurry; applying the catalyst slurry onto a polymer electrolyte membrane; and drying the catalyst slurry applied onto the polymer electrolyte membrane to form an electrode. The dispersion medium is a solvent capable of forming a plurality of grooves on a surface of the polymer electrolyte membrane, and, when the electrode is formed through the drying step, at least some of the grooves are filled with the catalyst, the ion conductor, or a mixture thereof.

A membrane electrode assembly (MEA) includes an ionically-conductive proton exchange membrane, an anode contacting a first side of the membrane and a cathode contacting a second side of the membrane and including third catalyst particles and a cathode GDL. The anode includes an anode gas diffusion layer (GDL), a first anode catalyst layer containing first catalyst particles, a hydrophobic polymer bonding agent, and a first ionomer bonding agent that lacks functional chains on a molecular backbone, and a second anode catalyst layer containing second catalyst particles and a second ionomer bonding agent that includes functional chains on a molecular backbone.

Membrane electrode assembly and method for fabricating the same. In one embodiment, the method may involve providing an anion exchange membrane and then applying catalyst coatings to opposing surfaces of the anion exchange membrane, whereby a membrane electrode assembly may be formed. Next, the membrane electrode assembly may be subjected to a two-part treatment process. In a first part of the process, the membrane electrode assembly may be swelled, at room temperature, by exposure to an aqueous ethanol solution vapor while being retained under tension in a frame. The aqueous ethanol solution vapor may be, for example, 80:20 by volume ethanol and water. In a second part of the process, the swollen membrane electrode assembly may be removed from the frame and then pressed, at room temperature, between two plates. A layer of rubber and a layer polytetrafluoroethylene may be placed between each plate and the swollen membrane electrolyte assembly.

An anode catalyst layer with high reversal tolerant capability includes an anode inner catalyst layer close to a proton exchange membrane and an anode outer catalyst layer close to a gas diffusion layer. At least the anode inner catalyst layer contains a reversal tolerant catalyst and a hydrophilic additive. The content of the hydrophilic additive in the anode inner catalyst layer is not less than that of the anode outer catalyst layer, or the water retention capability of the anode inner catalyst layer is not less than that of the anode outer catalyst layer.

A method for producing a liquid composition containing a fluoropolymer having sulfonic acid groups, trivalent cerium ions and water, by (1) irradiating a solution containing at least one cerium compound selected from cerium carbonate, cerium hydroxide and cerium oxide, the fluoropolymer and the water, with light at least partially in a wavelength region from 300 to 400 nm so that the ultraviolet irradiance on the surface of the solution is at least 0.1 mW/cm.sup.2 or (2) adding a reducing agent to a solution containing at least one cerium compound selected from cerium carbonate, cerium hydroxide and cerium oxide, the fluoropolymer and the water.

Disclosed are a method of manufacturing a membrane-electrode assembly and a membrane-electrode assembly manufactured using the same. The method includes forming a laminated structure, and treating the laminated structure, for example, by drying and heat treating. The laminated structure includes a release film, an anode layer, a porous support layer, and a cathode layer.

Herein disclosed is a method of making a fuel cell including forming an anode, a cathode, and an electrolyte using an additive manufacturing machine. The electrolyte is between the anode and the cathode. Preferably, electrical current flow is perpendicular to the electrolyte in the lateral direction when the fuel cell is in use. Preferably, the method comprises making an interconnect, a barrier layer, and a catalyst layer using the additive manufacturing machine.

Disclosed is a method for manufacturing a large-area thin-film solid oxide fuel cell, the method including: preparing an anode support slurry, an anode functional layer slurry, an electrolyte slurry, and a buffer layer slurry for tape casting; preparing an anode support green film, an anode functional layer green film, an electrolyte green film, and a buffer layer green film by tape casting the slurries onto carrier films; staking the green films, followed by hot press and warm iso-static press (WIP), to prepare a laminated body; and co-sintering the laminated body.