Patent ID: 7291414

Claim:
A fuel cell stack comprising: an active region including a stack of fuel cells, each fuel cell including a membrane electrode assembly (MEA) having a cathode side and an anode side, a cathode side diffusion media layer on the cathode side of the MEA, an anode side diffusion media layer on the anode side of the MEA, and an active region bipolar plate assembly positioned between opposing diffusion media layers in adjacent fuel cells, wherein the active region bipolar plate assembly includes nested bipolar plates defining cathode side flow channels and anode side flow channels; and an inactive feed region including a stack of membranes that form part of the MEAs in the stack of fuel cells and a feed region bipolar plate assembly, wherein the feed region bipolar plate assembly includes non-nested bipolar plates defining cathode side flow channels and anode side flow channels, where the cathode side flow channels in the feed region are in fluid communication with and are about the same size as the cathode side channels in the active region and the anode side flow channels in the feed region are in fluid communication with and are about the same size as the anode side flow channels in the active region, wherein the fuel cells do not include diffusion media layers in the inactive feed region.