A103 Analysis of Oxygen Transport Resistance in PEFC Cathode Catalyst Layer for Mechanism in Shutdown Process

Abstract

In polymer electrolyte fuel cells (PEFCs), the freezing of produced water makes cell performance worse below zero In this study, we investigated the freezing phenomena in the cathode catalyst layer (CL) by the experiments, and identified the effects of current density, cathode gas pressure, and oxygen concentration It was shown from the results that the ice distribution in the CL and the estimated amount of ice produced in the CL till the shutdown depend on the current density while they are independent of the cathode gas pressure and the oxygen molar concentration To clarify the main cause dominating these tendencies in the cold start, we introduced the effect of ice formation on an increase in the through-plane electrical resistance of the CL into the three phase boundary and the CL models, and examined the freezing mechanism in the CL