Theoretical performance analysis of microstructured air-breathing fuel cells

We present a theoretical analysis of an air-breathing polymer electrolyte membrane fuel cell that has a microstructured architecture and compare its performance to a fuel cell with a traditional planar arrangement. Air-breathing fuel cells exhibit unique performance characteristics due to a membrane dehydration regime associated with operation at higher current density and temperature. Our model features a membrane conductivity correlation that is applicable for low humidity and a finite-thickness model of the cathode catalyst layer that resolves ionic conduction. The analysis predicts a volumetric power density for the microstructured architecture that is 100% greater than that for the planar arrangement. (C) 2007 The Electrochemical Society.