4808 Research on Diagnosis Technique of PEFC Running Condition

Abstract

We have investigated the behavior of a polymer electrolyte fuel cell (PEFC) operated with supplying carbon monoxide (CO) in addition hydrogen (H_2) into the anode in order to develop the PEFC diagnosis method for anode CO poisoning. Using current-voltage (I-V) curves and electrochemical impedance spectroscopy (EIS), we analyze the overvoltage, electrooxidation of CO and phenomena of CO adsorption/desorption at the anode. I-V curves show that the output voltage decreases owing to the CO poisoning when anode potential is lower than CO electrooxidation potential. EIS shows that a PEFC can be simulated with an equivalent circuit model consisting of several elements ; activation and concentration overvoltages and adsorption/desorption. Their characteristic values can be used for the diagnosis of the CO poisoning.