Effect of Water Management Schemes on the Membrane Durability in PEMFCs

Abstract

The authors report the degradation behavior of polymer-electrolyte membrane fuel cells tested under two types of water-management schemes: the solid plate (SP) cells that mange water via flow and dew point control of the reactant gases, and water transport plate (WTP) cells that actively remove liquid through micro-porous bipolar plates. Comparative experiments were conducted. Cell performance degradation was tracked by periodic diagnostic testing. After cell testing, the residual mechanical strength of the membrane electrode assemblies was characterized. It was found that both water management schemes led to cell performance reduction via the loss of the electrochemical active area. However, the SP cell led to rapid reduction of membrane toughness. The WTP cell tended to preserve the membrane mechanical toughness better. Post-analysis found localized membrane failure in SP cell test during which a step change in performance occurred. Abrupt performance degradation was not observed for either of the WTP cell tests.