In situ-polymerized wicks for passive water management in proton exchange membrane fuel cells

An-delivery is typically the largest parasitic loss in PEM fuel cell systems. We develop a passive water management system that minimizes this loss by enabling stable, flood-free performance in parallel channel architectures, at very low all stoichiometries Our system employs in situ-polymerized wicks which conform to and coat cathode flow field channel walls, thereby spatially defining regions for water and air transport. We first present the fabrication procedure. which incorporates a flow held plate geometry comparable to many state-of-the-art architectures (e.g. stamped metal or injection molded flow fields) We then experimentally compare water management flow field performance versus a control case with no wick integration. At the very low air stoichiometry of 1 15, our system delivers a peak power density of 0.68 W cm(-2). This represents a 62% increase in peak power over the control case The open channel and manifold geometries are identical for both cases, and we demonstrate near identical met-to-outlet cathode pressure drops at all fuel cell operating points Our water management system therefore achieves significant performance enhancement without introducing additional parasitic losses (C) 2009 Elsevier B V All rights reserved.