The role of flow-field layout on the conditioning of a proton exchange membrane fuel cell

The importance of membrane electrode assembly (MEA) conditioning for proton exchange membrane (PEM) fuel cells under various operating conditions, such as reactant flow and cell voltage-current combination, has been well recognized, but few studies have considered the impact of the cell hardware design. In this study, the impact of flow-field layout on the conditioning of MEAs has been experimentally investigated. It is shown that the MEAs conditioned with serpentine flow-field layouts on both the anode and cathode side have better performance than the MEAs conditioned with straight-parallel flow-field layouts, and that the peak power density can be increased from 0.83 W/cm2 to 0.93 W/cm2 (about 12% increase) for the MEAs tested under the same operating condition of using humidified hydrogen and air at atmospheric pressure. This performance improvement is mainly due to the under-rib convection of the reactant gases in serpentine flow-field layouts that provides more uniform conditioning of the entire MEAs, compared with the MEAs conditioned with straight-parallel flow-field layouts for which the portion of the MEAs under the rib is not well conditioned, due to the lack of the reactant flow there.