The power output of hydrogen fuel cells quickly decreases
to zero if the fuel supply is interrupted. We demonstrate thin film solid
oxide fuel cells with nanostructured vanadium oxide anodes that generate
power for significantly longer time than reference porous platinum anode
thin film solid oxide fuel cells when the fuel supply is interrupted. The
charge storage mechanism was investigated quantitatively with likely
identified contributions from the oxidation of the vanadium oxide anode,
its hydrogen storage properties, and different oxygen concentration at the
electrodes. Fuel cells capable of storing charge even for short periods of
time could contribute to ultraminiaturization of power sources for mobile energy.