Probing the Water Content in Polymer Electrolyte Fuel Cells Using Neutron Radiography

This in-situ study examines the water content in polymer electrolyte fuel cells (PEFCs) using neutron radiography. Various conditions such as different polytetraflouroethylene (PTFE) loadings in the gas diffusion media including the micro-porous layer (MPL), different flow fields (single-channel and quad-serpentine channels), and co-/counter-flow configurations are investigated. We find that the highest water content occurs at a low current density when fixing the stoichiometry, and the PTFE loadings in the diffusion media greatly affect the amounts of water content in PEFCs. At low humidity, liquid water is found in the downstream area, increasing rapidly after its on-set. The effect of the relative humidity on water content is also examined.