Performance analysis of proton exchange membrane fuel cell in automotive applications

This paper deals with the performance analysis of a proton exchange membrane fuel cell in automotive applications and especially for start/stop phases. Start-Stop cycles are one of the main sources of degradation for fuel cell systems, embedded in the automotive applications, among other dynamic conditions as idling, load cycling or high power. In this study, polarization curves and electrochemical impedance spectra are used to analyze the degradation mechanisms inside fuel cell stack during start/stop cycling. Obviously, the carbon support of the catalyst layer is the main constituent that suffers performance degradation during the 2,600 successive cycles performed. The impedance measurement of a 5 kW PEM fuel cell stack revealed that the ohmic resistance does not vary whereas the charger transfer and mass transfer resistances increase drastically depending on the number of cycle repetitions. The oxygen reduction reaction impact due to the fuel/air interface is also visible even if the reactants are consumed with a dummy load for the shutdowns.