High-Resolution Neutron Radiography of Through-Plane Liquid Water Distribution in Polymer Electrolyte Membrane and Gas Diffusion Layer

We re-investigate our previously studied water transport phenomena under nonisothermal conditions by measuring the through-plane liquid water distribution across PEFC components with the state-of-the-art high-resolution neutron radiography. A corrective postprocessing procedure to eliminate artifacts arising from polymer electrolyte membrane (PEM) swelling in water thickness measurement is introduced for the first time. Presence of a water content gradient in the polymer electrolyte membrane was observed under large temperature gradient and high humidity conditions. Water distribution in gas diffusion layers (GDLs) was measured by replacing the PEM with a film of PTFE. The experiment yielded a pronounced liquid water peak at the PTFE interface. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.026209jes] All rights reserved.