Patent ID: 7425379

Claim:
A fuel cell module, for use with hydrogen as a first reactant and air, including oxygen as a second reactant and nitrogen as a non-reactive agent, the fuel cell module comprising: a fuel cell stack including at least one fuel cell, each fuel cell including an anode electrode, a cathode electrode and an electrolyte medium, comprising a proton exchange membrane, arranged between the anode electrode and the cathode electrode, wherein during normal operation the anode electrode is provided with the first reactant and the cathode electrode is provided with air; a parasitic load that is connectable across the anode and the cathode electrodes; and, a reactant reservoir, connectable to the anode electrode of each fuel cell, for storing an amount of the first reactant suitable for a shutdown process of the fuel cell module, whereby, in use when the fuel cell module is shutdown, the stored amount of the first reactant is drawn from the reactant reservoir and electrochemically reacts with an amount of the second reactant remaining in the fuel cell module, to electrochemically consume all of the amounts of the first and second reactants, thereby leaving a second mixture that substantially comprises the non-reactive agent wherein the fuel cell stack comprises: a cathode inlet port for supplying the first mixture to the cathode electrodes; a cathode outlet port for evacuating un-reacted amounts of the second reactant, amounts of the non-reactive agent and exhaust products from the cathode electrodes; an anode inlet port, fluidly connectable to the reactant reservoir, and for supplying the first reactant to the anode electrodes; and, an anode outlet port for evacuating un-reacted amounts of the first reactant and exhaust products from the anode electrodes; wherein the fuel cell module further comprises: a hydrogen supply port; an anode input valve, connectable between the hydrogen supply port and the reactant reservoir, for cutting-off a flow of hydrogen from the hydrogen supply port to the anode inlet port during the shutdown process; and a check valve connectable between the cathode inlet port and the anode inlet port; wherein the check valve opens at a predetermined pressure differential between an internal pressure in the cathode electrodes and an internal pressure in the anode electrodes, and remains closed when the internal pressures are approximately the same.