Abstract: The invention relates to bipolar plates for fuel cell systems. According to the invention, the component sheets of a bipolar plate (1) are formed for a welded joint (4, 5), such that between the profile regions (6) of the channel ducts (2), only small local surfaces remain as welding zones (10). The above is achieved by means of a corresponding shape of the profile molding (8, 9) 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 (2), 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.

Abstract: The invention relates to a bipolar plate (3) for a fuel cell arrangement (1), in particular for placement between two adjacent membrane electrode arrangements, comprising at least one or two plates disposed plane-parallel relative to one another, wherein a flow field (F) is formed from the channel structures made in the respective plate at least on one or both outer sides, respectively, said channel structures comprising a plurality of channels (K) running between a fluid inlet (E) and a fluid outlet (A) and webs (S) running between two channels (K). According to the invention, the channels (K) and/or the webs (S) comprise at least one varying channel width (b1), one varying web width (b2) and/or one varying channel distance (a) on at least one of the outer sides along a flow direction (R) of a fluid between the fluid inlet (E) and the fluid outlet (A).

Abstract: The invention relates to bipolar plates for fuel cell systems. According to the invention, the component sheets of a bipolar plate (1) are formed for a welded joint (4, 5), such that between the profile regions (6) of the channel ducts (2), only small local surfaces remain as welding zones (10). The above is achieved by means of a corresponding shape of the profile molding (8, 9) 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 (2), 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.