Gas diffusion nanocomposite layer with enhanced mass transport with surface functionalization by laser irradiation

초록

Gas and water mass transfer remain significant challenges in proton exchange membrane fuel cells (PEMFCs), making the surface properties and structural configuration of the gas diffusion layer (GDL) critical for performance. A newly proposed gas diffusion nanocomposite layer (GDNL) features a multi-walled carbon nanotube/polytetrafluoroethylene (MWCNT/PTFE) nanocomposite film with a laser-perforated pattern filled with carbon black/PTFE (CB/PTFE) microporous material, forming a hydrophilic?superhydrophobic columnar interface. In this design, laser irradiation induces hydrophilicity along the inner walls of the perforations, directing water transport through the hydrophilic interface. Meanwhile, the superhydrophobic CB/PTFE filling channels gas transport inside the structure and repels water outward, ensuring separated and efficient pathways for gas and water movement. This unique columnar interface in the LPM-GDNL design results in ~40% and ~50% improvements in current and power density in the concentration loss region at relative humidity levels of 50% and 100%, respectively, compared to conventional commercial carbon paper GDLs.