Abstract: A fuel cell system comprises a fuel cell, a switch control module and at least two switch modules; the switch modules each is coupled to a positive electrode and a negative electrode of the fuel cell, and comprises switch units; the switch units each comprises a switch; the switch comprises a control terminal, a current input terminal and a current output terminal; in at least one of the at least two switch modules, the switch unit further comprises a voltage division structure; the voltage division structure is coupled in series between the current input terminal and the positive electrode of the fuel cell, or, the voltage division structure is coupled in series between the current output terminal and the negative electrode of the fuel cell; the switch control module is respectively coupled to the control terminals of the switches of the at least two switch modules to respectively control on-off of the switches.

Abstract: A hydrogen generator working by hydrolysis of the metal borohydride is described comprising a reaction chamber (7) which in its bottom part has a liquid collecting area (30) and leads by short and non-complex connecting components to a conduit end (38) through which the exhaust products (31) of the reaction are discharged into the environment, generally the atmosphere and thereby saving weight and volume. By using given high pressures and temperatures for the reaction, the danger of crystallization of exhaust products is prevented.

Abstract: An electrochemical device comprising one or multiple self-humidifying electrochemical fuel cells, wherein each electrochemical fuel cell comprises a main surface (9) which can be used for an electrochemical reaction and can consume the oxygen contained in the air. A single air flow enters into the fuel cell and is divided into at least two parts of air flow inside the fuel cell. At least one of these parts of air flow has mass transfer contact with the main surface (9). Otherwise, at least another part of air flow has no mass transfer contact with the main surface (9). The air flow is divided by a separation sheet (5).

Abstract: A fuel cell arrangement comprises a fuel cell current source, peripheral units, a regulated hydrogen source for the fuel cell current source, based on the hydrolysis of a hydride and furthermore an electronic control circuit for controlling the fuel cell current source and an electronic control circuit for controlling the hydrogen source. The control circuit, for the fuel cell current source and the control circuit, for the hydrogen source are coupled together and the control of the current source and the hydrogen source carried out with mutually related adjustment.

Abstract: A fuel cell arrangement comprises a fuel cell current source, peripheral units, a regulated hydrogen source for the fuel cell current source, based on the hydrolysis of a hydride and furthermore an electronic control circuit for controlling the fuel cell current source and an electronic control circuit for controlling the hydrogen source. The control circuit, for the fuel cell current source and the control circuit, for the hydrogen source are coupled together and the control of the current source and the hydrogen source carried out with mutually related adjustment.

Abstract: A membrane-electrode unit (1) with integrated sealing edge for a polymer electrolyte membrane fuel cell having a polymer electrolyte membrane (2), an anode (3) arranged on one surface of the membrane and a cathode (4) arranged on the other surface of the membrane, is made from a layer material of anode material, cathode material and polymer electrolyte membrane material disposed therebetween, from which pieces of suitable size are severed, with the membrane, in the severed pieces, being covered completely by the electrodes on both of its sides. On the periphery of said piece, a sealing edge (5) is formed such that the sealing edge (5) penetrates an edge portion (6′, 7′) of at least one of the electrodes (3, 4) and adheres to the membrane portion adjacent the edge potion and/or the sealing edge adheres to the end faces of at least one of the electrodes and the end faces of the membrane.

Abstract: Gas diffusion electrodes (1) for polymer electrolyte membrane fuel cells are modified such that the diffusion of water therein is inhibited in comparison with un-modified electrodes. Polymer electrolyte membrane fuel cells with the modified gas diffusion electrodes can be operated, with on the average unchanged operating conditions, without addition of water, since the gas diffusion electrodes do not allow more water to escape than that formed during the reaction of burnable gas and oxidizing agent, and guarantee sufficient membrane moisture.

Abstract: Fuel cell stack and method of regulating membrane moisture of polymer electrolyte membranes of fuel cells of the fuel cell stack includes ascertaining electronically an average value of an electrical value corresponding to moisture of the polymer electrolyte membranes of a number of fuel cells of the fuel cell stack without utilization of an auxiliary electrode, the number of fuel cells ranging from two fuel cells to all fuel cells of the fuel cell stack; and adjusting the moisture of the polymer electrolyte membranes of the number of fuel cells to an optimum moisture as a function of the average value ascertained.

Abstract: A particularly inexpensive, homogeneous and porous gas diffusion electrode which comprises at least one electrically conductive, hydrophobic and gas-permeable gas diffusion layer, comprising a mechanically stable support material which is impregnated with at least one electrically conductive material having a bulk conductivity of ≧10 mS/cm is produced. The gas diffusion electrode can be coated with a catalytically active layer. The electrodes of the invention are particularly suitable for use in fuel cells and electrolysis cells.

Abstract: A particularly inexpensive, lightweight, homogeneous and porous gas diffusion electrode for polymer electrolyte membrane fuel cells is made in that carbonized carbon fiber nonwoven fabric is coated with a mixture of a soot suspension and a polytetrafluoroethylene suspension and sintered thereafter. The gas diffusion electrode may have a catalytically active layer applied thereto.