Abstract: A novel fuel cell design is provided having a combustion chamber manifold internal to a fuel cell stack and interfacing one or more anode passage outlets and cathode passage inlets. The combustion chamber is equipped to combine a primary source of oxidant gas with an anode exhaust stream and to combust the mixture, if desired, for use as fuel within the cathode passage. The fuel cell design also provides an external gas manifold for directing carrier gas to the cathode passages upstream of the cathode passage inlets for combining with the combustion chamber exhaust prior to entry into the cathode passages.