PEM Fuel Cell Operation under Air and O₂ Feed: Analysis of Cell Performance and Liquid Water Distributions

Abstract

Abstract A commercial 50 cm 2 PEM (polymer electrolyte membrane) fuel cell was operated at 2.0 bara and 60 °C with two different oxidant gases, namely air and oxygen. A 3 × 3 matrix of anode and cathode reactants relative humidity (RH a and RH c ) was used for a detailed characterization of the cell behavior. The cell performance and operating data including cell voltage and resistance were measured, and neutron radiographs were recorded during the entire operation to analyze the liquid water distributions within the cell. A quantitative analysis of the results is presented in this work, comparing the cell operation for both gases. The gain in cell voltage observed for the operation with O 2 , and the differences in the cell resistance and cell water content are quantitatively analyzed and discussed. Despite the differences in cell voltage, when the total volumetric cathode gas flow is maintained for air and oxygen feed, no significant differences are observed in the cell water content and water distribution.