For simplifying cooling of a fuel cell system which may be a single cell (1),
a stack (15) or a similar configuration and which comprises at least one
active membrane (2) sandwiched between an anode layer (4) and a cathode
layer (3) and comprising a catalyst, a fuel supply having access to the
anode layer and an air supply (17, 18) having access to the cathode layer,
while at the same time keeping the effectivity of the system with reference to
energy conversion, volume and weight favourable, the fuel cell system is to be
operated such that the air which is supplied by the air supply, is introduced by
pressure into the fuel cell system, passes along the cathode layer and then leaves
the fuel cell system, is used for both oxidant and coolant. For this purpose, the
air is introduced into the fuel cell system (1, 15) with a rate resulting
in a stoichiometric rate in the range between 25 and 140.
