Corrugated mesh flow channel and novel microporous layers for reducing flooding and resistance in gas diffusion layer-less polymer electrolyte fuel cells

Electrode flooding at the cathode impedes the increase in power density of polymer electrolyte fuel cells (PEFCs), limiting their use at high current densities. Liquid water can accumulate in the pores of the gas-diffusion layer (GDL), deteriorating performances significantly. This paper reports a novel fuel-cell structure for the reduction of electrode flooding utilizing corrugated mesh as gas-flow channels and gas diffusers placed directly onto the microporous layer (MPL) without a conventional GDL in between. The polarization curve of the corrugated-mesh fuel cell shows a lower flooding tendency at a high current density; however, the high-frequency resistance (HFR) of this fuel cell increases significantly as a result of fewer contact points between the corrugated mesh and MPL. In addition, MPL conductivity and rigidity are investigated in efforts to reduce the flow-channel pattern resistance. The rigidity of the MPL has a small effect on the reduction in HFR, which may be caused by an improved pressure distribution on the catalyst layer.