Enhanced Performance of Marine Polymer Electrolyte Fuel Cell without humidification Using Anode Gas Recirculation

The present study was carried out to clarify the effect of anode gas recirculation on PEFC performance without humidification. Raising the gas flow velocity in the channel to 2 m s-1 by increasing the anode gas recirculation promotes water transport from the anode gas to the membrane. Decreasing the pore diameter of a microporous layer (MPL)-coated gas diffusion layer (GDL) at the cathode is effective at preventing membrane dehydration, which enhances PEFC performance without humidification. However, decreasing the MPL pore diameter significantly increases the water breakthrough pressure, reducing the ability of the MPL to reduce the flooding under high humidity conditions. When using an MPL containing hydrophilic carbon nanotubes, it is possible to decrease the pore diameter without raising the water breakthrough pressure. This is effective at enhancing PEFC performance under both no and high humidity conditions, compared with that obtained for a hydrophobic MPL-coated GDL.