Abstract: A dynamoelectric machine includes a shaft, a rotor arranged fixedly on the shaft for conjoint rotation, and a slip ring system enabling a rotor winding system to be contacted electrically and including a slip ring body having slip rings arranged spaced-apart axially behind one another and assigned to an electrical phase. The slip ring body is connected fixedly to the shaft for conjoint rotation and has between an inner side thereof and the shaft a section which forms an axially open cavity on both skies. In a region of the slip ring system, the shaft is hollow with a hollow shaft portion assigned to the slip ring system for routing feed lines to the rotor winding system. Recesses are provided on the cavity axially on an inside and axially on an outside for introducing a cooling medium flow axially into the cavity and discharge thereof into an outlet region.

Abstract: A membrane electrode assembly includes a cathode, an anode, a proton-conductive membrane arranged between the cathode and the anode and a sealing frame which surrounds the cathode, the anode and the membrane at the edges thereof, wherein in the inner region of the sealing frame at least mutually superposed subregions of the cathode, of the anode and of the membrane are exposed, wherein the sealing frame in the layer thickness direction comprises a first sealing layer and a second sealing layer which are bonded to each other by an adhesive and wherein the first sealing layer and/or the second sealing layer has a reinforcement structure.

Abstract: A method of analyzing a functional layer of an electrochemical cell or an electrochemical sensor application includes conveying a predefined amount of test gas to a first surface of the functional layer, and quantitatively determining an amount of test gas that has passed through the functional layer using a detection unit located on a second surface of the functional layer, which second surface is opposite the first surface of the functional layer, wherein the test gas conveyed to the first surface of the functional layer is provided in a test gas chamber arranged on the first surface of the functional layer, characterized in that the test gas chamber is open towards the first surface of the functional layer and has an opening which has a defined length in the longitudinal direction (X) of the functional layer and a variably adjustable width in the transverse direction (Z).

Abstract: A membrane electrode assembly includes a cathode, an anode and a proton-conductive membrane, wherein the cathode includes a first metal-containing catalyst and a proton-conductive ionomer, the anode includes a proton-conductive ionomer, a second metal-containing catalyst that catalyzes the reaction of hydrogen to protons, and a third metal-containing catalyst that catalyzes the reaction of CO to CO2, a total mass ratio of platinum of the second catalyst and platinum of the third catalyst to a total mass ratio of metals of the second catalyst and the third catalyst, with the exception of platinum, is greater than 3:1, and the total mass per unit area of platinum of the second catalyst and platinum of the third catalyst is less than 0.4 mg/cm2.

Abstract: The invention relates to colloidal dispersions comprising nano-sized precious metal particles (e.g. platinum or platinum alloy particles) and at least one ionomer component having acidic groups. The method for its manufacturing is based on a neutralization and dissolving process of a suitable precious metal precursor compound with a liquid acidic ionomer component, followed by a reduction step. Suitable precious metal precursors consist of precious metal atoms, hydrogen atoms, oxygen atoms and optionally carbon atoms. Examples for precursors are H2Pt(OH)6, Pd(OH)2 or Ir(OH)4, preferred reducing agents are aliphatic alcohols or hydrogen. The invention further relates to pre-products for the manufacture of such colloidal dispersions, namely to compositions which contain precious metal precursors and at least one acidic ionomer compound.

Abstract: The present invention is directed to a method for preparing an integral 3-layer catalyst-coated membrane (CCM) for use in electrochemical cells, e.g. PEM (polymer-electrolyte membrane) fuel cells. The process comprising the steps of preparing a first catalyst layer on a supporting substrate, subsequently coating the first catalyst layer with an ionomer dispersion to form an ionomer layer (membrane), and applying a second catalyst layer on top of the ionomer layer. The ionomer dispersion applied in the membrane coating step has low viscosity in the range of 10 to 400 centipoises (cP) and an ionomer concentration in the range of 15 to 35 weight-%. With this method, CCMs with improved electrochemical performance and reduced cathode resistance are manufactured.

Abstract: The invention relates to Membrane Electrode Assemblies (“MEAs”) for solid-polymer-electrolyte proton-conducting membrane fuel cells (“PEM-FCs”) having better performance and improved durability, in particular when operated under severe electrochemical conditions such as fuel starvation and start-up/shut-down cycling. The MEAs are characterized in that at least one of its two electrode layers (EL1 and/or EL2) contains a first electrocatalyst (EC1) comprising an iridium oxide component in combination with at least one other inorganic oxide component and a second electrocatalyst (EC2/EC2?), which is free from iridium. Preferably, an iridium oxide/titania catalyst is employed as EC1. The MEAs reveal better performance, in particular when operated under severe operating conditions such as fuel starvation and start-up/shut-down cycling.

Abstract: The invention relates to a process for recycling fuel cell components containing fluorine-containing and precious metal-containing constituents: in this process, the fluorine-containing constituents are separated off from the precious metal-containing constituents by treatment with a medium present in the supercritical state. Preference is given to using water as supercritical medium. After the fluorine-containing constituents have been separated off, the precious metal-containing residues can be recovered in a recycling process without harmful fluorine or hydrogen fluoride emissions. The fluorine-containing constituents can likewise be recovered. The process is used in the recovery of precious metals and/or fluorine-containing constituents from membrane fuel cells, electrolysis cells, batteries, sensors and other electrochemical devices.

Abstract: The invention describes a process for producing a gas diffusion electrode which has a catalyst layer having a smooth surface, wherein the smooth surface of the catalyst layer is produced by bringing the catalyst layer in the moist state into contact with a transfer film and removing this transfer film after drying. In variant A, the catalyst layer is firstly produced on a transfer film and then transferred in the moist state to the gas diffusion layer. In variant B, the catalyst layer is applied to the gas diffusion layer, and a transfer film is then placed on top. In both cases, the structure produced in this way is subsequently dried. Before further processing, the transfer film is removed to give a gas diffusion electrode having a smooth catalyst surface which has a maximum profile peak height (Rp) of less than 25 microns. The electrodes are used for producing membrane-electrode assemblies for membrane fuel cells or other electrochemical devices.

Abstract: A membrane electrode assembly for polymer electrolyte fuel cells consisting of a polymer electrolyte membrane, both faces of which are in contact with porous reaction layers and gas distributor layers. The reaction layers contain noble metal catalysts supported on carbon and a proton-conducting polymer, a so-called ionomer. At least one of the two reaction layers also contains a noble metal black.

Abstract: The invention relates to a process for recycling fuel cell components containing fluorine-containing and precious metal-containing constituents: in this process, the fluorine-containing constituents are separated off from the precious metal-containing constituents by treatment with a medium present in the supercritical state. Preference is given to using water as supercritical medium. After the fluorine-containing constituents have been separated off, the precious metal-containing residues can be recovered in a recycling process without harmful fluorine or hydrogen fluoride emissions. The fluorine-containing constituents can likewise be recovered. The process is used in the recovery of precious metals and/or fluorine-containing constituents from membrane fuel cells, electrolysis cells, batteries, sensors and other electrochemical devices.

Abstract: A membrane electrode unit for polymer electrolyte fuel cells consisting of a polymer electrolyte membrane, both faces of which are in contact with porous reaction layers and gas distributor layers. The reaction layers contain noble metal catalysts supported on carbon and a proton-conducting polymer, a so-called ionomer. At least one of the two reaction layers also contains a noble metal black.