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.

Provided are composite electrolytes having a bio-based gel electrolyte in an ordered structure of a porous solid. In some embodiments, the gel electrolyte includes a glycolate gel, a glycerate gel, a bio-based compound-derived gel or a combination thereof. Also provided are electrochemical systems (electrodeposition), redox flow batteries, fuel cells, lithium-ion batteries and lithium-metal batteries including the composite electrolytes, and methods for producing gel electrolytes. In some embodiments, the methods including reacting a polyol, optionally ethylene glycol, propanediol, butanediol, pentanediol, diethylene glycol, glycerol, or any combination thereof, with a lithium metal and/or a lithium salt, optionally lithium hydroxide, a sodium salt, optionally sodium hydroxide (NaOH), NaTFSI, NaBF.sub.4, or NaPF.sub.6; an aluminum salt; a potassium salt, a magnesium salt; a calcium salt; a zinc salt; or any combination thereof.

Provided are composite electrolytes having a bio-based gel electrolyte in an ordered structure of a porous solid. In some embodiments, the gel electrolyte includes a glycolate gel, a glycerate gel, a bio-based compound-derived gel or a combination thereof. Also provided are electrochemical systems (electrodeposition), redox flow batteries, fuel cells, lithium-ion batteries and lithium-metal batteries including the composite electrolytes, and methods for producing gel electrolytes. In some embodiments, the methods including reacting a polyol, optionally ethylene glycol, propanediol, butanediol, pentanediol, diethylene glycol, glycerol, or any combination thereof, with a lithium metal and/or a lithium salt, optionally lithium hydroxide, a sodium salt, optionally sodium hydroxide (NaOH), NaTFSI, NaBF.sub.4, or NaPF.sub.6; an aluminum salt; a potassium salt, a magnesium salt; a calcium salt; a zinc salt; or any combination thereof.

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.

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.

The present invention relates to a membrane electrode unit comprising a polymer membrane doped with a mineral acid as well as two electrodes, characterized in that the polymer membrane comprises at least one polymer with at least one nitrogen atom and at least one electrode comprises a catalyst which is formed from at least one precious metal and at least one metal less precious according to the electrochemical series.

The present invention relates to a membrane electrode unit comprising a polymer membrane doped with a mineral acid as well as two electrodes, characterized in that the polymer membrane comprises at least one polymer with at least one nitrogen atom and at least one electrode comprises a catalyst which is formed from at least one precious metal and at least one metal less precious according to the electrochemical series.

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.

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.