Ageing Tests at Constant Currents and Associated Modeling of High Temperature PEMFC MEAs
Résumé
In this work, seven commercially available high temperature(HT) membrane electrode assemblies (MEAs), using a phos-phoric acid doped polybenzimidazole (PBI) membrane, weretested at six constant current densities during mostly around540 h: 1, 0.6, 0.4, 0.2, 0.1, and 0 A cm–2. The MEA aged at0.6 A cm–2appears to be the less degraded one and the MEAsworking at 0 and 1 A cm–2seem to be the most degradingones. Degradations are supposed to be mainly due to the car-bon corrosion of electrodes and the loss of electrolyte withthe MEA aged at 1 A cm–2. The characterization periods havea significant impact on cell ageing. The corrosion of carbonsupport is considered here to be the major degradation forthe tests carried out between 0 and 0.6 A cm–2. A degradationrate was calculated using the voltage from the polarizationcurves and it appears to be more relevant compare to thedegradation rate calculated using the voltage during endur-ance period. The modeling approach shows promisingresults and it seems that the electrochemical surface area,measured by cyclic voltammetry, can be included into themodeling in order to obtain higher parameter consistency.