On/off cycling test of low-temperature PEM fuel cell at fully humidified conditions

Accelerated stress testing is one of the most used approaches to characterize the performance and the degradation of the membrane electrode assembly (MEA) in low-temperature hydrogen polymer electrolyte membrane fuel cells (PEMFC). A standard JRC on/off testing procedure was used to characterize two sets of commercial MEAs, by ElectroChem and by PaxiTech, respectively. Performance characteristics prior to and after the on/off procedure were measured. The changes in the resistivity of the MEA were examined by electrochemical impedance spectroscopy (EIS). The EIS data were analyzed and interpreted by a suitable equivalent circuit that consisted of a resistor and the Voigt?s structure in series with constant phase elements. Water on the anode side and the cathode side of the PEMFC was collected during the on/off procedure. The fluoride emission rate was determined from the collected water to obtain information about the chemical degradation of the MEA samples.