Patent ID: 7655337

Claim:
A fuel cell for producing electrical energy, the fuel cell comprising: a fuel cell stack including a) a set of single plate solid metal substrate bi-polar plates, each bi-polar plate in the fuel cell stack comprising i) a first channel field disposed on a first face of the bi-polar plate and including a set of channels configured to distribute hydrogen, ii) a second channel field disposed on a second face of the bi-polar plate and including a second set of channels configured to distribute oxygen, wherein a channel included in the first channel field has an overlapping channel depth that extends past a channel depth for a channel included in the second channel field, iii) a first manifold that extends through the bi-polar plate from the first face to the second face and configured to deliver a gas to the first channel field or receive a gas from the first channel field; iv) a first flow buffer formed as a trough into the first face of the bi-polar plate and configured to receive a first gaseous flow from a first channel in the first set of channels and a second gaseous flow from a second channel in the first set of channels and to output the first and second gaseous flows in the first set of channels to a third channel in the first set of channels, wherein the flow buffer is configured to reduce a pressure difference between the first and second gaseous flows in the first set of channels before outputting the first and second gaseous flows to the third channel in the first set of channels; v) a second flow buffer formed as a trough into the second face of the bi-polar plate, positioned at least partially opposite to the first flow buffer formed into the first face of the bi-polar plate, and configured to receive a first gaseous flow from a first channel in the second set of channels and a second gaseous flow from a second channel in the second set of channels and to output the first and second gaseous flows in the second set of channels to a third channel in the second set of channels, wherein the second flow buffer is configured to reduce a pressure difference between the first and second gaseous flows in the second set of channels before outputting the first and second gaseous flows to the third channel in the second set of channels, and b) a membrane electrode assembly disposed between two bi-polar plates, the membrane electrode assembly including a hydrogen catalyst, an oxygen catalyst and an ion conductive membrane that electrically isolates the hydrogen catalyst from the oxygen catalyst.