Abstract: The present invention relates to membrane electrode assemblies comprising two electrochemically active electrodes separated by a polymer electrolyte membrane, there being a polyimide layer on each of the two surfaces of the polymer electrolyte membrane that are in contact with the electrodes. The present membrane electrode assemblies may be used in particular for producing fuel cells which have a particularly high long-term stability.

Abstract: The present invention relates to an acid-doped polymer membrane based on polyazoles. The acid-doped polymer membrane can be used in a variety of applications because of its excellent mechanical properties and is useful as polymer electrolyte membrane (PEM) in PEM fuel cells. A doped polymer membrane based on polyazoles is obtained by a process comprising the steps of: A) casting a film using a solution of polymers based on polyazoles in a polar, aprotic organic solvent; B) drying the film formed in step A) until it is self-supporting; C) treating the film obtained in step B) with a treatment liquid at a temperature in the range from room temperature to the boiling point of the treatment liquid; D) drying and/or dabbing the film treated according to step C) to remove the treatment liquid from step C); and E) doping the film treated according to step D) with a doping agent.

Abstract: The invention relates to a membrane-electrode unit comprising a) two electrochemically active electrodes divided by a polymer electrolytic membrane, wherein the surfaces of said polymer electrolytic membrane are in contact with the electrodes in such a way that the first electrode partially or entirely covers the front side of the polymer electrolytic membrane and the second electrode partially or entirely covers the rear side thereof, b) a sealing material is applied to the front and rear sides of the polymer electrolytic membrane, wherein the polymer electrolytic membrane is provided with one or several recesses and the sealing material applied to the front side of the polymer electrolytic membrane is in contact with the sealing material applied to the rear side thereof. A method for producing said membrane-electrode unit and fuel cells provided therewith are also disclosed.

Abstract: The present invention relates to an acid-doped polymer membrane based on polyazoles. The acid-doped polymer membrane can be used in a variety of applications because of its excellent mechanical properties and is useful as polymer electrolyte membrane (PEM) in PEM fuel cells. A doped polymer membrane based on polyazoles is obtained by a process comprising the steps of: A) casting a film using a solution of polymers based on polyazoles in a polar, aprotic organic solvent; B) drying the film formed in step A) until it is self-supporting; C) treating the film obtained in step B) with a treatment liquid at a temperature in the range from room temperature to the boiling point of the treatment liquid; D) drying and/or dabbing the film treated according to step C) to remove the treatment liquid from step C); and E) doping the film treated according to step D) with a doping agent.

Abstract: Fixtures and methods of using fixtures to facilitate the fabrication of devices having thin films, for example, gasketed components of fuel-cell membrane electrode assemblies, are disclosed. In one aspect, the fixture comprises a plate having an aperture and means for mounting a thin film to the plate wherein the thin film at least partially obstructs the aperture and wherein the thin film provides a surface for mounting at least one component of a device. Another aspect is a fixture for facilitating the fabrication of a fuel-cell membrane electrode assembly which includes a plate having an aperture and means for mounting a gasket to the plate wherein the gasket at least partially obstructs the aperture and wherein the gasket provides a surface for mounting at least one electrode for a fuel-cell membrane electrode assembly.

Abstract: A method and apparatus for handling thin films, for example, for handling and assembling membranes in fuel cell electrodes. The apparatus includes a translatable vacuum table for mounting the thin film, a perforated drum having a source of vacuum for removing the thin film from the vacuum table, and a transfer assembly having a perforated surface and a source of vacuum for transferring the thin film from the perforated drum to a target location. When the thin films are provided in containers, the apparatus may also include means for opening the containers to access the thin film within. Removal of the thin film from the transfer assembly may be aided by a thin film release device, for example, a plurality of moveable wires. The apparatus may be automated, for example, the apparatus may included automated controllers and robotic arms to facilitate the handling of thin film materials.

Abstract: The present invention relates to an acid-doped polymer membrane based on polyazoles. The acid-doped polymer membrane can be used in a variety of applications because of its excellent mechanical properties and is useful as polymer electrolyte membrane (PEM) in PEM fuel cells. A doped polymer membrane based on polyazoles is obtained by a process comprising the steps of: A) casting a film using a solution of polymers based on polyazoles in a polar, aprotic organic solvent; B) drying the film formed in step A) until it is self-supporting; C) treating the film obtained in step B) with a treatment liquid at a temperature in the range from room temperature to the boiling point of the treatment liquid; D) drying and/or dabbing the film treated according to step C) to remove the treatment liquid from step C); and E) doping the film treated according to step D) with a doping agent.

Abstract: The invention relates to a membrane-electrode unit comprising a) two electrochemically active electrodes divided by a polymer electrolytic membrane, wherein the surfaces of said polymer electrolytic membrane are in contact with the electrodes in such a way that the first electrode partially or entirely covers the front side of the polymer electrolytic membrane and the second electrode partially or entirely covers the rear side thereof, b) a sealing material is applied to the front and rear sides of the polymer electrolytic membrane, wherein the polymer electrolytic membrane is provided with one or several recesses and the sealing material applied to the front side of the polymer electrolytic membrane is in contact with the sealing material applied to the rear side thereof. A method for producing said membrane-electrode unit and fuel cells provided therewith are also disclosed.

Abstract: The present invention relates to a method of preparing a solution of a polymer comprising recurring azole units, which comprises dissolving a sufficiently dried polymer comprising recurring azole units of the formula where the radicals Ar, Ar1 and Ar2 are tetravalent, divalent or trivalent aromatic or heteroaromatic groups and the radicals X, which are identical within a repeating unit, are each an oxygen atom, a sulfur atom or an amino group bearing a hydrogen atom, a group having 1–20 carbon atoms, preferably a branched or unbranched alkyl or alkoxy group, or an aryl group as further radical, in N,N-dimethylacetamide having a sufficiently low water content at a temperature above room temperature under an inert gas atmosphere, wherein a sufficiently dried polymer comprising recurring azole units of the formula (1) or (2) of which 90% by weight based on the total weight of the polymer comprising recurring azole units has a particle size of less than 1 mm is used.

Abstract: The present invention relates to membrane electrode assemblies comprising two electrochemically active electrodes separated by a polymer electrolyte membrane, there being a polyimide layer on each of the two surfaces of the polymer electrolyte membrane that are in contact with the electrodes. The present membrane electrode assemblies may be used in particular for producing fuel cells which have a particularly high long-term stability.

Abstract: Fixtures and methods of using fixtures to facilitate the fabrication of devices having thin films, for example, gasketed components of fuel-cell membrane electrode assemblies, are disclosed. In one aspect, the fixture comprises a plate having an aperture and means for mounting a thin film to the plate wherein the thin film at least partially obstructs the aperture and wherein the thin film provides a surface for mounting at least one component of a device. Another aspect is a fixture for facilitating the fabrication of a fuel-cell membrane electrode assembly which includes a plate having an aperture and means for mounting a gasket to the plate wherein the gasket at least partially obstructs the aperture and wherein the gasket provides a surface for mounting at least one electrode for a fuel-cell membrane electrode assembly.

Abstract: A method and apparatus for handling thin films, for example, for handling and assembling membranes in fuel cell electrodes. The apparatus includes a translatable vacuum table for mounting the thin film, a perforated drum having a source of vacuum for removing the thin film from the vacuum table, and a transfer assembly having a perforated surface and a source of vacuum for transferring the thin film from the perforated drum to a target location. When the thin films are provided in containers, the apparatus may also include means for opening the containers to access the thin film within. Removal of the thin film from the transfer assembly may be aided by a thin film release device, for example, a plurality of moveable wires. The apparatus may be automated, for example, the apparatus may included automated controllers and robotic arms to facilitate the handling of thin film materials.

Abstract: The present invention relates to an acid-doped polymer membrane based on polyazoles, a process for producing it and its use.

Abstract: The present invention relates to a method of preparing a solution of a polymer comprising recurring azole units, which comprises dissolving a sufficiently dried polymer comprising recurring azole units of the formula 1

Abstract: The composition described comprises 30 to 99.5% by weight of a sulfonated aromatic polyether ketone which has an ion-exchange capacity of from 1.3 to 4.0 meq (—SO3H)/g of polymer, and from 0.5 to 70% by weight of a polybenzimidazole.

Abstract: Polymer composition, membrane comprising the same, process for production thereof and use thereof The composition described comprises 30 to 99.5% by weight of a sulfonated aromatic polyether ketone which has an ion-exchange capacity of from 1.3 to 4.0 meq (—SO3H)/g of polymer, and from 0.5 to 70% by weight of a polybenzimidazole. This composition can, as can a sulfonated polyether ketone of PEK type, be processed to give membranes, preferably used in fuel cells.