METHOD FOR SPECIFICALLY AND TEMPORARILY HUMIDIFYING AN HT-PEM FUEL CELL AND CORRESPONDING HT-PEM FUEL CELL

摘要

An essential component of PEM fuel cells is a membrane electrode assembly (MEA) that comprises a cathode and anode disposed on both sides of a polymer membrane, and respective cathode chambers and anode chambers that are capped on both sides by a bipolar plate. In practice it may happen that in the idle state of the battery, when no current is drawn, the resistance of the membrane electrode assembly (MEA) increases rapidly. According to the invention, the cathode is supplied with a limited amount of hydrogen or a hydrogen-containing gas instead of air, whereby hydrogen and oxygen is recombined by the catalytic reaction, thereby producing water and heat. The polymer membrane is thus humidified and its resistance can be specifically reduced. In order to monitor the fuel cell, a measuring device (8) for the ohmic resistance can control a switch device (7) for the process gases via a control device (5, 6) for humidifying the membrane (12).