A gas diffusion nanocomposite layer with a hydrophilic–superhydrophobic columnar interface for enhanced water and gas transport

Abstract

The mass transfer of gas and water remains a significant challenge in proton exchange membrane fuel cells (PEMFCs). Surface properties and structural configuration of a gas diffusion layer (GDL) are crucial in PEMFC performance. A gas diffusion nanocomposite layer (GDNL) was newly proposed to have a hydrophilic–superhydrophobic columnar interface in a multi-walled carbon nanotube/polytetrafluoroethylene nanocomposite with a laser-perforated pattern filled with carbon black/PTFE microporous filling (LPM). LPM-GDNL has localized water transport in the columnar interface with hydrophilicity induced by laser irradiation, while the superhydrophobic filling confines the gas transport inside and repels water out to the hydrophilic interface, leading to separate water and gas transport. This unique hydrophilic–superhydrophobic columnar interface of LPM-GDNL boosts the current and power density by 40% and 50% more in the concentration loss region at relative humidity levels of 50% and 100%, respectively, in comparison with the commercial carbon paper GDL.