Ageing Tests at Constant Currents and Associated Modeling of High Temperature PEMFC MEAs

Abstract

Abstract In this work, seven commercially available high temperature (HT) membrane electrode assemblies (MEAs), using a phosphoric acid doped polybenzimidazole (PBI) membrane, were tested at six constant current densities during mostly around 540 h: 1, 0.6, 0.4, 0.2, 0.1, and 0 A cm −2 . The MEA aged at 0.6 A cm −2 appears to be the less degraded one and the MEAs working at 0 and 1 A cm −2 seem to be the most degrading ones. Degradations are supposed to be mainly due to the carbon corrosion of electrodes and the loss of electrolyte with the MEA aged at 1 A cm −2 . The characterization periods have a significant impact on cell ageing. The corrosion of carbon support is considered here to be the major degradation for the tests carried out between 0 and 0.6 A cm −2 . A degradation rate was calculated using the voltage from the polarization curves and it appears to be more relevant compare to the degradation rate calculated using the voltage during endurance period. The modeling approach shows promising results and it seems that the electrochemical surface area, measured by cyclic voltammetry, can be included into the modeling in order to obtain higher parameter consistency.