Experimental analysis of a degraded open-cathode PEM fuel cell stack

Abstract

The well-known challenges to be overcome in PEM fuel cell research are their relatively low durability and high costs for the platinum catalysts. Thus, this work focuses on factors that impact durability and the links to the fuel cell performance. Therefore a degraded, open-cathode, 20-cell, PEM fuel cell stack, which was used in a laboratory test station for characterization experiments, was analyzed experimentally. Voltage transients during external perturbations, such as changing temperature, humidity and stoichiometries show that degradation affects individual cells quite differently throughout the lifetime of the stack. Electrochemical impedance spectroscopy (EIS) data presents non-reversible catalyst layer and membrane degradation of several cells. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) are in progress in order to validate the results of the electrical analysis and elucidate catalyst and membrane degradation.