Abstract: There is provided a method for the activation of a fuel cell. An exemplary method comprises operating the fuel cell entirely or partially at least briefly in an electrolysis regimen during galvanic operation.

Abstract: In low-temperature fuel cells according to prior art, the problem often arises that the diffusion layer of the cathode is filled by water which is permeated or produced on the cathode, such that oxygen can no longer be transported to the catalyst layer of the cathode in a frictionless manner. As a result, said fuel cells are regularly used with a high excess of oxygen in order to reduce the cited transport problems for the oxygen. The inventive fuel cell enables said problem to be solved in that the arrangement of the diffusion layer and the catalyst layer of the cathode is inverted. The diffusion layer, which is embodied in such a way as to also conduct ions, is directly adjacent to the electrolyte membrane. The catalyst layer oriented towards the free cathode space can advantageously directly react with the supplied oxygen without further transport problems.

Abstract: The invention relates to a low-temperature fuel cell stack comprising a specific device for the supply of fuel. Said low-temperature fuel cell stack is characterised in that, in addition to the central fuel supply device, it comprises a supply or storage device for a liquid fuel, and a plurality of separately controllable dosing devices that lead into the central fuel supply device, especially respectively upstream of a distribution channel to the individual cells. Controllable valves, controllable piezoelectric pumps or thermally controllable supply elements are suitable as dosing devices. The invention also relates to a method for operating one such low-temperature fuel cell stack, which advantageously enables a defined concentration of fuel, or a defined humidity of the oxidation medium, to be adjusted at certain points in the fuel cell stack, especially on the inlet for the individual cells.

Abstract: In low-temperature fuel cells according to prior art, the problem often arises that the diffusion layer of the cathode is filled by water which is permeated or produced on the cathode, such that oxygen can no longer be transported to the catalyst layer of the cathode in a frictionless manner. As a result, said fuel cells are regularly used with a high excess of oxygen in order to reduce the cited transport problems for the oxygen. The inventive fuel cell enables said problem to be solved in that the arrangement of the diffusion layer and the catalyst layer of the cathode is inverted. The diffusion layer, which is embodied in such a way as to also conduct ions, is directly adjacent to the electrolyte membrane. The catalyst layer oriented towards the free cathode space can advantageously directly react with the supplied oxygen without further transport problems.

Abstract: In a direct-methanol fuel cell stack with an at least partial circulation (7, 9) of the fuel, according to the invention a means is arranged in this circulation for reducing the concentration of an undesired byproduct. This means is comprised especially of a further electrochemical cell (8) to which electric current is applied and which at least partly transforms the byproducts by an electrochemical reduction reaction again to methanol and water. Since the concentration of byproducts is small, the loss in electric current required for the additional reduction reaction has no noticeable effect on the efficiency of the fuel cell stack.

Abstract: The invention relates to a device for cleaning waste gases for a direct alcohol fuel cell or for a direct alcohol fuel cell stack, comprising at least one supply line for supplying an oxidizing agent into a cathode space of a fuel cell and at least one evacuation line for evacuating waste gas out of a fuel cell. The supply line and evacuation line are arranged next to one another at least in one area and are separated by a porous layer. A catalytic converter is placed on the surface of the porous layer oriented toward the evacuation line. In the inventive waste gas cleaning device, the advantages of an internal utilization of heat and of an at least partial water circuit with an effective catalytic conversion and reduction of removed non-converted alcohol, particularly methanol, locally unite at one location of the fuel cell system. The waste gas cleaning device simultaneously serves to preheat and wet the supplied oxidizing agent and can be advantageously provided with a very compact design.

Abstract: In a direct-methanol fuel cell stack with an at least partial circulation (7, 9) of the fuel, according to the invention a means is arranged in this circulation for reducing the concentration of an undesired byproduct. This means is comprised especially of a further electrochemical cell (8) to which electric current is applied and which at least partly transforms the byproducts by an electrochemical reduction reaction again to methanol and water. Since the concentration of byproducts is small, the loss in electric current required for the additional reduction reaction has no noticeable effect on the efficiency of the fuel cell stack.

Abstract: An electrolyzer has a metal fitting for supply or discharge or electricity or discharge of gas produced in the electrolyzer and into which, from the passage forming system within the electrolyzer has an electrically insulating tube extending into the metal fitting and hermetically sealed with respect to it, at the end electrode through which the electrically insulating tube passes, or the passage system so that parasitic currents are led along this schematically insulating tube for a length sufficient to render the parasitic losses significant.

Abstract: A diaphragm of porous sinter material for alkaline water electrolysis characterized by a porous sinter metal oxidized at least partially to metal oxide. A frame structure of the sinter body is provided especially wire net. The base metal of the sinter body is formed by nickel, iron or copper. The method includes forming a porous metal sinter body and oxidizing the same at elevated temperature in oxygen-containing atmosphere. The method for production of nickel oxide diaphragms furthermore includes applying to a nickel net a pasty mass of nickel powder containing a binder and burning. Applying in a thin layer as by brushing nickel powder of a particle size of about 1 to 10 mm in a rubber solution in toluene upon a carrier, especially a nickel net, and this arrangement is subjected to sintering at 700.degree. to 1,000.degree. C. for a time or duration of 10 to 20 minutes in inert or reducing atmosphere especially in hydrogen and the sinter body which is obtained is subjected to roasting in air at 1000.degree.

Abstract: A method for increasing the current yield or electrolytic efficiency of a sion electrolysis, especially water electrolysis, with which an anodic oxygen separation occurs. Lithium ions are added to the fusion electrolyte. Such lithium ions may be added by adding lithium as hydroxide or fluoride, sulfate or carbonate. The lithium addition amounts to at least 15 Mol % of the melt. Electrolyte is formed by a lithium hydroxide containing alkali hydroxide melt.

Abstract: On a sheet steel carrier a suspension containing a binder and nickel powder r a powder containing a nickel alloy in a volatile suspension medium is applied, with or without an additional pore-forming material, and the sintered to produce a porous sintered layer. Alternatively, this sintered layer can be obtained by depositing and consolidating the powdered mixture on the carrier with the aid of a plasma gun. A nickel/zinc alloy is then precipitated electrolytically on the sintered material thus produced and, finally, the zinc is dissolved out by dipping in lye. The carrier may be of metal and particularly a wire lattice of nickel or iron. It may also be a solid electrolyte membrane, such as a disc of .beta.-Al.sub.2 O.sub.3.

Abstract: A method for producing hydrogen according to a hybrid process. A low oxide, hich is formed at a high temperature from a higher oxide accompanied by splitting-off of oxygen, is introduced into an aqueous electrolyte and is reoxidized anodically along with simulataneous cathodic hydrogen generation. The oxide is returned into the high temperature range. As an oxide, antimony oxide, especially antimony tetraoxide, is used, with the oxide being formed anodically in a melt-flow electrolysis and being decomposed again into antimony trioxide and oxygen at approximately 850.degree. to 1000.degree. C. As an electrolyte, an alkali melt, and especially a melt having a sodium hydroxide base, may be used. The electrolyte may be formed by a possibly salt, especially sodium fluoride, containing mixture of sodium hydroxide and antimony trioxide in a mole ratio of 1:0.5 to 1:5.0, with a water content of approxaimately 1 to 5% by weight. The anode chamber is separated from the cathode chamber by a .beta.

Abstract: Method and apparatus for generating hydrogen and oxygen. Water is electroically decomposed in an electrolysis cell having a molten electrolyte which contains alkali ions and has a high OH.sup.- ion activity. The anode and cathode chambers are separated from one another by a separator made of an ion conducting aluminum oxide modification known as .beta.-Al.sub.2 O.sub.3. Hydrogen and oxygen are then separately withdrawn.