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:
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:
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 and polymer electrolyte fuel cells and methods of production thereof, in which a polymer membrane, containing at least one basic polymer membrane, is sandwiched between two flat gas diffusion electrodes each of which is loaded with a dopant, whereby after reaching a mass transport equilibrium for the exchange of the dopant between the gas diffusion electrodes and the polymer membrane, the polymer membrane has a conductivity of at least 0.1 S/m at a temperature of no less than 25° C.
摘要:
A membrane-electrode assembly and polymer electrolyte fuel cells and methods of production thereof, in which a polymer membrane, containing at least one basic polymer membrane, is sandwiched between two flat gas diffusion electrodes each of which is loaded with a dopant, whereby after reaching a mass transport equilibrium for the exchange of the dopant between the gas diffusion electrodes and the polymer membrane, the polymer membrane has a conductivity of at least 0.1 S/m at a temperature of no less than 25° C.
摘要:
A proton-conducting electrolyte membrane is disclosed, comprising at least one base material and at least one dopant, which is the reaction product of an at least dibasic inorganic acid with an organic compound, comprising one acidic hydroxyl group, or the condensation product of said compound with a polybasic acid. The membrane may be produced by a single step method, which avoids the use of dangerous materials and environmental pollutants. Subsequent doping of the membrane, e.g., in conjunction with assembly of the membrane electrode assembly (MEA) is not excluded. The electrolyte membrane has a high and constant mechanical stability and flexibility, excellent chemical and thermal stability and a high and constant conductivity. The membrane may be used in a fuel cell in a wide temperature range from 50° C. to more than 200° C., for example, whereby the fuel cell has a high and constant power level over the entire temperature range.
摘要:
A proton-conducting electrolyte membrane is disclosed, comprising at least one base material and at least one dopant, which is the reaction product of an at least dibasic inorganic acid with an organic compound, comprising one acidic hydroxyl group, or the condensation product of said compound with a polybasic acid. The membrane may be produced by a single step method, which avoids the use of dangerous materials and environmental pollutants. Subsequent doping of the membrane, e.g., in conjunction with assembly of the membrane electrode assembly (MEA) is not excluded. The electrolyte membrane has a high and constant mechanical stability and flexibility, excellent chemical and thermal stability and a high and constant conductivity. The membrane may be used in a fuel cell in a wide temperature range from 50° C. to more than 200° C., for example, whereby the fuel cell has a high and constant power level over the entire temperature range.
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.