Fuel cell stack having terminal element located at specified location

Abstract

The present invention provides a fuel stack comprising: a plurality of fuel cell units stacked together in a direction of stacking each of which comprises an electrolyte element, a pair of electrodes holding the electrolyte element therebetween, and a pair of separators holding the electrodes therebetween; a pair of terminal plates each of which is disposed outside an end fuel cell unit located at an end of the stacked fuel cell units; and a terminal element extending outwardly in the direction of stacking from the outside surface of at least one of the terminal plates; wherein the location from which the terminal element extends is located within an area on the terminal plate, corresponding to an area in a passage for an oxidizing gas formed in the end fuel cell unit disposed adjacent to the terminal element where the partial pressure of water vapor is lower than the saturated water vapor pressure. More preferably, the terminal element is disposed as close to the centerline of the terminal plate as possible so that the total electrical resistance of the terminal element and the terminal plate is minimized. By this configuration, an increase in the total electrical resistance and water vapor condensation in the fuel cell units located at the ends of the stack may be prevented.