摘要 |
For an improved cooling a fuel cell stack (1) with cooling fins extending around the periphery of the stack, the section of the stack has a somewhat longitudinal shape. In detail, the stack comprises: a plurality of fuel cell s electrically connected in series and having equivalent active section areas and circumferences, each fuel cell comprising a laminate of layers, these comprising an electrolyte membrane and catalyst, electrode and gas diffusion layers the functions of which may be combined in any combination in multifunction layers; end and separator plates delimiting each cell; and cooling layers (9) the cooling function of which also may be combined with other layers in respective multifunction layers, the cooling layers each projecting beyond the circumferential outer periphery (14) of the laminate o f the other layers thereby comprising an inner active section area (15) and a peripheral cooling fin area (11). For extending the circumference of the active area (15) and thereby the section of the cooling layer and the area o f the fins, the ratio (14:15) of circumference (14) and active area (15) of th e stack (1), defined by the geometrical shape of the active area (15), extends the corresponding ratio of a square active area. Also described is the use o f expanded graphite for one orseveral of the following components of a fuel cell: bipolar plate, electrode, and gas diffusion layer. |