Patent ID: 8343681

Claim:
A fuel cell stack comprising: membrane electrode assemblies (MEAs) disposed in a stack; an end plate disposed on an end of the fuel cell stack; and first bipolar plates and second bipolar plates that are sequentially disposed between the MEAs, the first and second bipolar plates each comprising, a main body having opposing first and second surfaces; first flow channels to supply a fuel to the MEAs; second flow channels to supply an oxidant to the MEAs; first and second manifolds connected to ends of the first flow channels; third and fourth manifolds connected to ends of the second flow channels; and first through fourth through holes that are isolated from the flow channels and the manifolds of their respective bipolar plates, wherein, the through holes of the first bipolar plates are connected to the manifolds of the second bipolar plates, and the through holes of the second bipolar plates are connected to the manifolds of the first bipolar plates, wherein the end plate has a first hole connected to one of the through holes connected to the first flow channels of the second bipolar plates, and a second hole connected to one of the through holes connected to the first flow channels of the first bipolar plates, the fuel cell stack further comprises a connection unit on the end plate, to connect the first hole to the second hole, to recirculate the fuel from the first flow channels of the second bipolar plates to the flow channels of the first bipolar plate through the end plate.