A new polyelectrolyte multilayer coated proton-exchange membrane for electrolysis and fuel cell applications has been developed for electrolysis and fuel cell applications. The polyelectrolyte multilayer coated proton-exchange membrane comprises: a cation exchange membrane, and a polyelectrolyte multilayer coating on one or both surfaces of the cation exchange membrane. The polyelectrolyte multilayer coating comprises alternating layers of a polycation polymer and a polyanion polymer. The polycation polymer layer is deposited on and is in contact with the cation exchange membrane. The top layer of the polyelectrolyte multilayer coating can be either a polycation polymer layer or a polyanion polymer layer.

A polyelectrolyte multilayer membrane has been developed for redox flow batteries and other electrochemical reaction applications. The polyelectrolyte multilayer membrane comprises an ionically conductive thin film composite membrane comprising a microporous support membrane, a hydrophilic ionomeric polymer coating layer on the surface of the microporous support membrane, and a polyelectrolyte multilayer coating on the second surface of the hydrophilic ionomeric polymer coating layer (the side opposite the support membrane). The polyelectrolyte multilayer coating comprises alternating layers of a polycation polymer and a polyanion polymer. Methods of making the polyelectrolyte multilayer membrane and redox flow battery system including the polyelectrolyte multilayer membrane are also described.

A method for bonding together two or more acid-doped polybenzimidazole films is provided. The method includes, in the following order: placing a first acid-doped polybenzimidazole film on a first substrate to form a first film/substrate assembly and placing a second acid-doped polybenzimidazole film on a second substrate to form a second film/substrate assembly; heating the first and second film/substrate assemblies to a temperature sufficient to soften the first and second acid-doped polybenzimidazole films; positioning the second film/substrate assembly atop the first film/substrate assembly, such that polybenzimidazole polymer chains of the first acid-doped polybenzimidazole film interact with polybenzimidazole polymer chains of the second acid-doped polybenzimidazole film; and re-hydrolyzing the first and second acid-doped polybenzimidazole films, such that the polybenzimidazole polymer chains of the first and second acid-doped polybenzimidazole films are therefore reformed and interlocked with each other to bond together the first and second acid-doped polybenzimidazole films.

A method for bonding together two or more acid-doped polybenzimidazole films is provided. The method includes, in the following order: placing a first acid-doped polybenzimidazole film on a first substrate to form a first film/substrate assembly and placing a second acid-doped polybenzimidazole film on a second substrate to form a second film/substrate assembly; heating the first and second film/substrate assemblies to a temperature sufficient to soften the first and second acid-doped polybenzimidazole films; positioning the second film/substrate assembly atop the first film/substrate assembly, such that polybenzimidazole polymer chains of the first acid-doped polybenzimidazole film interact with polybenzimidazole polymer chains of the second acid-doped polybenzimidazole film; and re-hydrolyzing the first and second acid-doped polybenzimidazole films, such that the polybenzimidazole polymer chains of the first and second acid-doped polybenzimidazole films are therefore reformed and interlocked with each other to bond together the first and second acid-doped polybenzimidazole films.

To provide an electrode catalyst layer, a membrane electrode assembly, and a polymer electrolyte fuel cell capable of improving the mass transport properties and proton conduction properties in the electrode catalyst layer and exhibiting high power generation performance for a longer time. An electrode catalyst layer according to an embodiment of the present invention is an electrode catalyst layer configured to be bonded to a polymer electrolyte membrane for use in a polymer electrolyte fuel cell, the electrode catalyst layer including: a catalytic substance; a conductive carrier supporting the catalytic substance; a polymer electrolyte; and one or more types of fibers containing at least a polymer fiber, wherein, among the fibers, the number of fibers having an axis inclination θ of 0°<θ<45° relative to a bonding surface between the polymer electrolyte membrane and the electrode catalyst layer is more than 50% of the total number of the contained fibers.

To provide an electrode catalyst layer, a membrane electrode assembly, and a polymer electrolyte fuel cell capable of improving the mass transport properties and proton conduction properties in the electrode catalyst layer and exhibiting high power generation performance for a longer time. An electrode catalyst layer according to an embodiment of the present invention is an electrode catalyst layer configured to be bonded to a polymer electrolyte membrane for use in a polymer electrolyte fuel cell, the electrode catalyst layer including: a catalytic substance; a conductive carrier supporting the catalytic substance; a polymer electrolyte; and one or more types of fibers containing at least a polymer fiber, wherein, among the fibers, the number of fibers having an axis inclination θ of 0°<θ<45° relative to a bonding surface between the polymer electrolyte membrane and the electrode catalyst layer is more than 50% of the total number of the contained fibers.

A continuous automated process and production line for preparing an acid doped polybenzimidazole, PBI, polymer membrane film for use in a fuel cell, the process having a washing stage, a drying procedure, and a doping stage.

A continuous automated process and production line for preparing an acid doped polybenzimidazole, PBI, polymer membrane film for use in a fuel cell, the process having a washing stage, a drying procedure, and a doping stage.

A lithiated carbon phosphonitride material is made by, for example, reacting P(CN).sub.3 with LiN(CN).sub.2 in solution (for example, dimethoxyethane or pyridine), then drying the solution to obtain the product. The material is a thermoset that is stable to over 400° C. and exhibits up to 10.sup.−3 S.Math.cm2 of Li.sup.+ conductivity.

A lithiated carbon phosphonitride material is made by, for example, reacting P(CN).sub.3 with LiN(CN).sub.2 in solution (for example, dimethoxyethane or pyridine), then drying the solution to obtain the product. The material is a thermoset that is stable to over 400° C. and exhibits up to 10.sup.−3 S.Math.cm2 of Li.sup.+ conductivity.