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.

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.

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.

Provided are a method for producing a liquid composition which is capable of eliminating clouding of a liquid with cerium (IV) hydroxide particles in a relatively short time, and methods for producing a polymer electrolyte membrane, a catalyst layer and a membrane/electrode assembly, each having excellent durability, in a relatively short time. A method for producing a liquid composition containing a fluoropolymer having sulfonic acid groups, trivalent cerium ions and water, which comprises (1) irradiating a solution containing at least one cerium compound selected from the group consisting of 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 the group consisting of cerium carbonate, cerium hydroxide and cerium oxide, the fluoropolymer and the water.

The present disclosure relates to a polymer electrolyte membrane for medium and high temperature, a preparation method thereof and a high-temperature polymer electrolyte membrane fuel cell including the same, more particularly to a technology of preparing a composite membrane including an inorganic phosphate nanofiber incorporated into a phosphoric acid-doped polybenzimidazole (PBI) polymer membrane by adding an inorganic precursor capable of forming a nanofiber in a phosphoric acid solution when preparing phosphoric acid-doped polybenzimidazole and using the same as a high-temperature polymer electrolyte membrane which is thermally stable even at high temperatures of 200-300° C. without degradation of phosphoric acid and has high ion conductivity.

The present disclosure relates to a polymer electrolyte membrane for medium and high temperature, a preparation method thereof and a high-temperature polymer electrolyte membrane fuel cell including the same, more particularly to a technology of preparing a composite membrane including an inorganic phosphate nanofiber incorporated into a phosphoric acid-doped polybenzimidazole (PBI) polymer membrane by adding an inorganic precursor capable of forming a nanofiber in a phosphoric acid solution when preparing phosphoric acid-doped polybenzimidazole and using the same as a high-temperature polymer electrolyte membrane which is thermally stable even at high temperatures of 200-300° C. without degradation of phosphoric acid and has high ion conductivity.

A method for producing a microporous material comprising the steps of: providing an ultrahigh molecular weight polyethylene (UHMWPE); providing a filler; providing a processing plasticizer; adding the filler to the UHMWPE in a mixture being in the range of from about 1:9 to about 15:1 filler to UHMWPE by weight; adding the processing plasticizer to the mixture; extruding the mixture to form a sheet from the mixture; calendering the sheet; extracting the processing plasticizer from the sheet to produce a matrix comprising UHMWPE and the filler distributed throughout the matrix; stretching the microporous material in at least one direction to a stretch ratio of at least about 1.5 to produce a stretched microporous matrix; and subsequently calendering the stretched microporous matrix to produce a microporous material which exhibits improved physical and dimensional stability properties over the stretched microporous matrix.

A method for producing a microporous material comprising the steps of: providing an ultrahigh molecular weight polyethylene (UHMWPE); providing a filler; providing a processing plasticizer; adding the filler to the UHMWPE in a mixture being in the range of from about 1:9 to about 15:1 filler to UHMWPE by weight; adding the processing plasticizer to the mixture; extruding the mixture to form a sheet from the mixture; calendering the sheet; extracting the processing plasticizer from the sheet to produce a matrix comprising UHMWPE and the filler distributed throughout the matrix; stretching the microporous material in at least one direction to a stretch ratio of at least about 1.5 to produce a stretched microporous matrix; and subsequently calendering the stretched microporous matrix to produce a microporous material which exhibits improved physical and dimensional stability properties over the stretched microporous matrix.

Disclosed herein a monovalent-ion-selective composite membrane comprising a polymeric cation exchange membrane and a metal-oxide-based layer, wherein said metal-oxide-based layer comprises a metal oxide or an organic-inorganic hybrid polymer, of e.g. Zn, Al, Mg, Si, Cu, W, Ni, or Ti. Also disclosed are the methods for the preparation of the membrane, and also electrodialysis assemblies comprising the membranes.

An anion exchange polymer includes aryl ether linkage free polyarylenes having aromatic/polyaromatic rings in polymer backbone and a tethered alkyl quaternary ammonium hydroxide side groups. This anion exchange polymer may be utilized in an anion exchange process and may be made into a thin anion transfer membrane. An ion transfer membrane may be mechanically reinforced having one or more layers of functional polymer based on a terphenyl backbone with quaternary ammonium functional groups and an inert porous scaffold material for reinforcement. An anion exchange membrane may have multilayers of anion exchange polymers which each containing varying types of backbones, varying degrees of functionalization, or varying functional groups to reduce ammonia crossover through the membrane.