Daimler Ag

Thomas Kunick

Felix Blank

Markus Schudy

Florian Finsterwalder

Joerg Kleemann

Jörg Kleemann

The invention relates to bipolar plates for fuel cell systems. According to the invention, the component sheets of a bipolar plate () are formed for a welded joint (), such that between the profile regions () of the channel ducts (), only small local surfaces remain as welding zones (). The above is achieved by means of a corresponding shape of the profile molding () of the component sheets. As a result of said reduction of the welding zones to small regions of the total surface, a larger proportion of the area is available for the channels (), in other words, the channel cross-section and hence the coolant flow can be increased. At the same time the structure for the use of gas diffusion layers made from non-wovens, textiles or paper can be optimized.

Bipolar plate for fuel cells

The invention relates to a bipolar plate for a fuel cell stack, which comprises at least a an anode-side sub-plate. An interior of the bipolar plate is enclosed by the sub-plates, with a fluid port area arranged having at least one fluid port, over which a fluid can be conveyed to the fluid channels. The fluid channels are arranged on at least one of the flat sides, as well as a manifold zone, over which the fluid can be distributed to its assigned fluid channels and an accumulation zone, over which the fluid can be carried away from the fluid channels to another fluid port area. At least one of the sub-plates has a uniform arrangement of raised support points in the manifold zone and/or accumulation zone. Apart from the peripherally situated support points, a negative support point of the same type is designed adjacent to each raised support point inside the manifold zone and/or the accumulation zone.

Bipolar plate and fuel cell unit

Proposed is a PEM fuel cell that comprises a separator plate assembly with a charging chamber, which is partitioned off by a partition wall and via charging spots has a fluid connection to an adjoining cathode chamber. The partition wall is designed so that the depths of the charging channels in the charging chamber and the depths of the distribution channels in the adjoining cathode chambers change in such a way that the quantity of oxidant that is charged at a charging spot from the charging chamber into the cathode chamber can be fixed in advance. As a result, the charging of oxidant, which has not been humidified or only slightly, into the cathode chamber can be improved with regard to the curve of the relative humidity along the cathode. Also proposed is a method for manufacturing a separator plate assembly suitable for a PEM fuel cell.

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Illerkirchberg, Germany

Thomas Kunick