Diagnosis and modelling of proton-exchange-membrane fuel cell via electrochemical-impedance-spectroscopy and Acoustic-Emission measurements

The diagnosis and modelling of flooding or drying is an important factor in improving the reliability and durability of PEMFCs. Indeed, flooding and drying lead to a reduction in the output voltage delivered by the fuel cell. Among the various techniques, electrochemical impedance spectroscopy (EIS) and Acoustic Emission (EA) are powerful tools. In this study, EIS and AE measurements were carried out respectively on a 500 W stack and on a 25 cm² fuel cell. EIS measurements and its modelling by an electrical equivalent circuit model revealed that flooding mainly affects the transfer resistance and the cathodic Warburg impedance. AE measurements show that it is possible to follow the water content within the fuel cell. Coupling this two methods seem to be an interesting diagnosis tool.