The present invention relates to a method for sealing a coolant chamber of a bipolar plate of a fuel cell, the fuel cell having at least one membrane-electrode unit and the bipolar plate having a first bipolar plate half and a second bipolar plate half, at least one of the bipolar plate halves having a coolant distributing structure and the coolant chamber that is formed at least by the coolant distributing structure being formed between the bipolar plate halves. The invention also relates to a fuel cell with at least one bipolar plate and at least one membrane-electrode unit, the bipolar plate having a first bipolar plate half and a second bipolar plate half, at least one of the bipolar plate halves having a coolant distributing structure and a coolant chamber that is formed at least by the coolant distributing structure being formed between the bipolar plate halves, and the at least one bipolar plate being arranged in a flat-extending manner against the membrane-electrode unit to form a gas chamber of an anode or a cathode of the fuel cell between the bipolar plate and the membrane-electrode unit.
Fuel cells may have multiple bipolar plates and membrane-electrode units. In the production of bipolar plates, it is also known that these bipolar plates may in each case have two bipolar plate halves. It is at the same time also possible in particular that one bipolar plate half on one side of the plate may have a gas distributing structure, for example for hydrogen in the case of an anode of the fuel cell or for air in the case of a cathode of the fuel cell, and the other side of the plate may have a coolant distributing structure for the distribution of a coolant. It is known to permanently connect the two bipolar plate halves in in the form of a point or points, a line or lines and/or flat over part of their extent by adhesive bonding, welding, soldering or brazing or similar connecting processes. It is also known to arrange a seal at the outer region of such a bipolar plate. Both possibilities are motivated by preventing coolant from escaping from the coolant chamber that is formed between the two bipolar plate halves.
In addition, it is known likewise to arrange seals between a bipolar plates and a membrane-electrode units of a fuel cell. Such seals or sealing arrangements are known for example from DE 10 2006 056 468 A1 or DE 199 08 555 A1. These seals are used for ensuring that the gases used in the fuel cell, in particular hydrogen and air, likewise cannot escape undesirably from the fuel cell.
However, a disadvantage here is that, in addition to the sealing of the gas chambers, either a separate sealing of the coolant chamber or a coolant-tight, permanent connection of the bipolar plate halves is necessary. Both variants are cost-intensive and require increased expenditure in terms of both material and time in the production and/or assembly of such a fuel cell.