摘要:
The invention relates to a fuel-cell stack with an external media supply, comprising a plurality of stacked fuel-cell elements, each containing a proton-conductive polymer membrane, which is located between a flat anode electrode and a flat cathode electrode, each electrode being in contact with a separator plate containing canal structures for supplying a reaction gas, evacuating superfluous reaction gas and water that has been produced and/or for distributing a heat transfer medium. At least one collection/distribution container, which is connected to the canal structures of a plurality of separator plates, distributes the reaction gas or the heat transfer medium or collects superfluous reaction gas and water that has been produced or the heat transfer medium. The collection/distribution container is configured as a hood that covers a plurality of fuel-cell elements, the edge of said hood being sealed in relation to the covered elements. The seal comprises at least a first sealing layer that is configured as a solid seal and a second sealing layer, which is in direct contact with the covered fuel-cell elements and at least partially compensates the offsets between the neighbouring fuel-cell elements, the second sealing layer consisting of a highly viscous plastic with permanent plastic characteristics.
摘要:
The invention relates to an insulating element for a fuel cell stack, which is composed of a thermally insulating plastic or plastic composite material. The insulating element is connected to the end plate and the bipolar end plate of the stack and achieves virtually uniform distribution of temperature and flow density along the fuel cell stack in the cell operating mode. As a result, the condensation of product water is prevented. The efficiency of the fuel cell stack is increased since it is possible to dispense with external heating of the stack by a cell current and costly measuring and control technology,
摘要:
A membrane electrode assembly (MEA) for a fuel cell, which has a planar polymer membrane. This membrane, in a tangentially inner area, is coated on both sides with electrode structure, and, in a tangentially outer area projecting at least on one side beyond the electrode structure coating, is connected to a sealing member. A marginal zone of the polymer membrane is embedded in the elastomer sealing member. The sealing member extends tangentially inward to a transition area that lies tangentially between the outer area and the inner area, where it overlaps the electrode structures on outer faces of the electrode structures, on both of the sides of the polymer membrane.
摘要:
Gas diffusion electrodes with improved proton conduction between an electrocatalyst located in a catalyst layer and an adjacent polymer electrolyte membrane, capable of being used at operating temperatures up to or above the boiling point of water, ensuring lasting high gas permeability. Also, a production method and corresponding fuel cells. At least one part of the particles of an electrically conductive carrier material in the catalyst layer is at least partially loaded with at least one porous, proton-conducting polymer which can be used up to or above the boiling point of water. Loading and development of the porous structure is carried out in a phase inversion method. The gas diffusion electrodes can be used in high temperature fuel cells working at temperatures up to or above the boiling temperature of water without a drop in performance in continuous operation.
摘要:
A membrane for fuel cells, which is characterized by a homogeneous absorption and good retention of doping agents, and which guarantees a high mechanical stability at high temperatures when doped. Such membranes consist of at least one polymer, whose nitrogen atoms are chemically bonded to a central atom of a derivative of a polybasic inorganic oxo acid. The membranes are produced from polymer solutions that are devoid of water and oxo acid derivatives, by heating the solution that has been introduced into a membrane mold until a self-supporting membrane has been formed and then by thermally regulating the latter. Inventive fuel cells having a membrane electrode assembly (MEA) that comprises a membrane of the invention and phosphoric acid as the doping agent have, for example, an impedance of 0.5-1 Ωcm2 at a measuring frequency of 1000 Hz and at an operating temperature of 160° C. and a gas flow for hydrogen of 170 mL/min and for air of 570 mL/min. They can be used as high-temperature polyelectrolyte membrane fuel cells for a working temperature of up to at least 250° C.
摘要:
A membrane electrode assembly (MEA) for a fuel cell, which has a planar polymer membrane. This membrane, in a tangentially inner area, is coated on both sides with electrode structure, and, in a tangentially outer area projecting at least on one side beyond the electrode structure coating, is connected to a sealing member. A marginal zone of the polymer membrane is embedded in the elastomer sealing member. The sealing member extends tangentially inward to a transition area that lies tangentially between the outer area and the inner area, where it overlaps the electrode structures on outer faces of the electrode structures, on both of the sides of the polymer membrane.
摘要:
The invention provides an improved fuel cell system and a method of operating a fuel cell, which ensure that the fuel cell can be operated at high efficiency without irreversible damage. The fuel cell system according to the invention has at least one fuel cell with a fuel cell stack and with separator plates, which are equipped with inlets and outlets for a heat transfer medium, a thermostat, a heat transfer medium circuit, which has a transport device for the heat transfer medium and includes at least the fuel cell and the thermostat, at least one temperature sensor for the fuel cell and a monitoring and control unit for the temperature of the fuel cell. With the invention it is possible to operate the fuel cell in a range close to the preset optimum operating temperature.
摘要:
A membrane for fuel cells, which is characterized by a homogeneous absorption and good retention of doping agents, and which guarantees a high mechanical stability at high temperatures when doped. Such membranes consist of at least one polymer, whose nitrogen atoms are chemically bonded to a central atom of a derivative of a polybasic inorganic oxo acid. The membranes are produced from polymer solutions that are devoid of water and oxo acid derivatives, by heating the solution that has been introduced into a membrane mold until a self-supporting membrane has been formed and then by thermally regulating the latter. Inventive fuel cells having a membrane electrode assembly (MEA) that comprises a membrane of the invention and phosphoric acid as the doping agent have, for example, an impedance of 0.5-1 Ωcm2 at a measuring frequency of 1000 Hz and at an operating temperature of 160° C. and a gas flow for hydrogen of 170 mL/min and for air of 570 mL/min. They can be used as high-temperature polyelectrolyte membrane fuel cells for a working temperature of up to at least 250° C.
摘要:
A device and a process are described for membrane electrophoresis or electrofiltration. The device contains at least one input chamber, one output chamber, and one cathode chamber and anode chamber each, whereby the individual chambers are separated from one another by membranes, and are integrated into a permanently attached module with membranes, and whereby the electrodes are integrated into the module, and the module is connected to constructions enabling continuous flow through the input and output chambers, as well as through the electrode chambers. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader quickly to ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the appended issued claims. 37 CFR §1.72(b).