A method of operating a fuel cell stack to mitigate fuel cell degradation due to startup and shutdown by hydrogen / nitrogen storage

摘要

A method of operating a fuel cell stack comprising: operating a fuel cell stack (100) having an anode side (16) and a cathode side (14), the operation including flowing hydrogen into the anode side (16) and flowing oxygen and nitrogen comprising air into the cathode side (14), generating electricity and operating a primary electrical device (62) connected to the stack (100) by means of electricity; Turning off the stack (100), comprising: separating the stack (100) from the primary electrical device (62); Stopping the flow of oxygen and nitrogen comprising air into the cathode side (14) and maintaining a hydrogen overpressure on the anode side (16); Preventing the flow of hydrogen from the anode side (16) and consuming of oxygen in the cathode side (14) by hydrogen, due to the suppressed anode-side hydrogen flow from the anode side (16) to the cathode side (14) through the solid electrolyte membrane (12) of the fuel cell stack ( 100) passes; thereafter shorting the fuel cell stack (100) by closing a circuit comprising the fuel cell stack (100) and a resistor (68); and thereafter inhibiting the flow of hydrogen into the anode side (16) and inhibiting the flow of exhaust gas from the cathode side (14).