Patent attributes
A power source with miniaturized SOFC fuel cells has: a stack (20) made up of the fuel cells (2), the volume of which is less than 10−3m3; a channel system (24, 25, 26) in which reactants, namely gaseous fuel (50) and also air (40), can be fed to the cells (2) and the fuel that is partially depleted in the cells is subjected to afterburning; a casing (10, 11) and a heat exchanger (6) where supplied air can be heated up with the exhaust gas (60) from the afterburning. The fuel cells contain a disc-shaped solid electrolyte (30) which in addition to ion conducting components also includes electron conducting components which cause an ohmic loss. In this way the quantity ratio of these components is so designed that in an idling operation of the power source a heat flow from the cells to the environment can be compensated by the ohmic loss.
