Effect of wettability-distribution pattern of the gas diffusion layer with a microgrooved separator on polymer electrolyte fuel cell performance

In this study, the combination of a gas diffusion layer (GDL) with wettability distribution and gas-flow channels with microgrooves is proposed to reduce the concentration overvoltage of polymer electrolyte fuel cells. The effects of the wettability-distribution pattern and linear angle of the stripe-wise wettability distribution of the GDL on the cell performance are experimentally investigated. Examination of the wettability-distribution pattern show that not only the liquid-water distribution inside a hybrid GDL but also the liquid-water control on the GDL surface are important factors to consider in reducing the concentration overvoltage. Furthermore, in considering the hybrid angle effect, when the angle with the gas channel is shallow, especially at 20°, the critical current and maximum power are maximized.