Abstract: A fuel cell stack including a bypass is provided. The fuel cell stack includes a plurality of electricity generating cells in the known manner. A bypass is included for reducing the water entering the electricity generating cells of the fuel cell stack. The bypass may comprise at least one bypass cell disposed adjacent the first electricity generating cell in the stack. The bypass cell comprises a pair of separator plates defining an anode side and a cathode side. The bypass cell includes a conductive spacer comprising gas diffusion media disposed between the pair of separator plates. The bypass cell preferably blocks the cathode port on the separator plate. In this manner, the cell is inactive and does not produce electricity. The anode port of the cell remains open and an anode feed flows through the bypass to reduce water provided to the first electricity-generating cell. Alternatively or additionally, the cathode port remains open. Further the bypass may be placed before the cell stack itself.

Abstract: In at least certain embodiments, the present invention relates to a fuel cell stack comprising a fuel cell assembly having opposite first and second ends, a wet end fuel cell adjacent the first end, a dry end fuel cell adjacent the second end, and a plurality of repeating fuel cells disposed between the wet end and dry end fuel cells. In at least certain embodiments, the wet end fuel cell comprises a unipolar plate and the repeating fuel cells each comprise one-half of each adjacent bipolar plate. In at least certain embodiments, the unipolar plate has a first oxidant rate, and at least one of the bipolar plates has a second oxidant rate, with the first oxidant rate being less than the second oxidant rate.

Abstract: In at least certain embodiments, the present invention relates to a fuel cell stack comprising a fuel cell assembly having opposite first and second ends, a wet end fuel cell adjacent the first end, a dry end fuel cell adjacent the second end, and a plurality of repeating fuel cells disposed between the wet end and dry end fuel cells. In at least certain embodiments, the wet end fuel cell comprises a unipolar plate and the repeating fuel cells each comprise one-half of each adjacent bipolar plate. In at least certain embodiments, the unipolar plate has a first coolant rate, and at least one of the bipolar plates has a second coolant rate, with the first coolant rate being less than the second coolant rate.