Abstract: A solid polymer fuel cell comprising a membrane electrode assembly that is in adhesive contact with a first flow field plate around the circumferential edge of the membrane electrode assembly and in non-adhesive contact with a second flow field plate, and an elastomeric manifold seal member that circumscribes at least one manifold opening of the first flow field plate and the second flow field plate. In this configuration, the adhesive substantially seals a first reactant gas while the manifold seal member substantially seals a second reactant gas, thereby improving sealing reliability and simplifying the seal design without overly compressing and damaging the circumferential edge of the membrane electrode assembly.

Abstract: A solid polymer fuel cell comprising a membrane electrode assembly that is in adhesive contact with a first flow field plate around the circumferential edge of the membrane electrode assembly and in non-adhesive contact with a second flow field plate, and an elastomeric manifold seal member that circumscribes at least one manifold opening of the first flow field plate and the second flow field plate. In this configuration, the adhesive substantially seals a first reactant gas while the manifold seal member substantially seals a second reactant gas, thereby improving sealing reliability and simplifying the seal design without overly compressing and damaging the circumferential edge of the membrane electrode assembly.

Abstract: A membrane electrode assembly comprises an ion exchange membrane, an anode positioned on one side of the membrane and a cathode positioned on the other side of the membrane so that a portion of the cathode extends outside of the anode area on the oxidant outlet side of the fuel cell such that any hydrogen leaked from the anode side to the cathode side due to any defects (holes) existing in the membrane near the oxidant outlet is recombined with the oxygen on the cathode side before it reaches the oxidant outlet and no hydrogen is present in the oxidant stream exhausted from the fuel cell.

Abstract: An electrochemical power generation system includes a fuel cell stack having an oxidant delivery system, an oxygen sensor for measuring the oxygen concentration of ambient air in the vicinity of the power generation system, and a hydrogen concentration sensor for measuring a hydrogen concentration in the ambient air in the vicinity of the power generation system. A controller is configured to cease operation of the power generation system, for example ceasing delivery of fuel to the fuel cell stack, when either the hydrogen concentration measured by the hydrogen concentration sensor exceeding a hydrogen concentration threshold or the oxygen concentration measured by the oxygen sensor falling below an oxygen concentration threshold.

Abstract: An electrochemical power generation system includes a fuel cell stack having an oxidant delivery system, an oxygen sensor for measuring the oxygen concentration of ambient air in the vicinity of the power generation system, and a hydrogen concentration sensor for measuring a hydrogen concentration in the ambient air in the vicinity of the power generation system. A controller is configured to cease operation of the power generation system, for example ceasing delivery of fuel to the fuel cell stack, when either the hydrogen concentration measured by the hydrogen concentration sensor exceeding a hydrogen concentration threshold or the oxygen concentration measured by the oxygen sensor falling below an oxygen concentration threshold.

Abstract: An electrochemical power generation system includes a fuel cell stack having an oxidant delivery system for delivering air from the ambient environment to the oxidant inlet of the stack, an oxygen sensor for measuring the oxygen concentration of ambient air in the vicinity of the power generation system. A controller coupled to the oxygen sensor is configured to cease operation of the power generation system when the oxygen concentration of the ambient air in the vicinity of the power generation system falls below an oxygen concentration threshold. The power generation system may also include a purge valve associated with a fuel outlet from the stack.

Abstract: An electrochemical power generation system includes a fuel cell stack having an oxidant delivery system for delivering air from the ambient environment to the oxidant inlet of the stack, an oxygen sensor for measuring the oxygen concentration of ambient air in the vicinity of the power generation system. A controller coupled to the oxygen sensor is configured to cease operation of the power generation system when the oxygen concentration of the ambient air in the vicinity of the power generation system falls below an oxygen concentration threshold. The power generation system may also include a purge valve associated with a fuel outlet from the stack.