Effects of Hardware Design and Operation Conditions on PEM Fuel Cell Water Flooding

In this paper, membrane electrode assemblies were constructed using catalyst-coated membranes to investigate proton-exchange membrane fuel cell water flooding. Two major fuel cell hardware variations, namely flowfield design and Teflon loading of the gas diffusion layer (GDL), were tested to explore their effects on water flooding. A flowfield with triple serpentine flow channels showed heavier water flooding than that with single serpentine flow channels. Increasing the Teflon loading in the GDL reduced water flooding effectively. Several fuel cell operating conditions, including air stoichiometry, current density, relative humidity (RH), backpressure, and temperature, were also tested to identify their effects on water flooding. It was observed that the water flooding severity increased with decreasing air stoichiometry, as well as with increasing temperature, RH, backpressure, and current density. Among these operation conditions, air stoichiometry (or air flow rate) and RH played more important roles in reducing water flooding.