A Novel Gas Diffusion Layer with High Flux for Enhanced Performance in Proton Exchange Membrane Fuel Cells

Enabling the efficient operation of proton exchange membrane fuel cells (PEMFCs) at elevated current densities is imperative for developing hydrogen energy power systems. An optimally engineered gas diffusion layer (GDL) that exhibits enhanced water management properties and superior gas permeability significantly contributes to the electrochemical efficiency of PEMFCs. Nevertheless, the conventional approach to GDL fabrication, which involves infiltration of the microporous layer (MPL) into the macroporous substrate (MPS), markedly reduces gas flux; consequently, this process compromises the efficiency of oxygen diffusion and leads to concentration polarization. Furthermore, the irregular interface phase between the MPL and MPS augments the transport resistance of the reactants. In this work, we introduced a facile strategy for constructing novel high-flux GDLs by employing nonsolvent-induced phase inversion of polyvinylidene fluoride. As a result, the GDLs with high gas flux, uniform hydrophobicity, and low oxygen transport resistance were obtained, thereby elevating both the mass transfer and power generation performance of the PEMFC. It is concluded that the high gas permeability of GDLs contributes to the formation of efficient water–gas transport channels in the membrane electrode assembly, which provides a guarantee for applications of PEMFCs in high-performance fields. Specifically, in the H₂/air system, the cell assembled using this kind of GDL (GDL-25) exhibited a remarkable power density of 1.42 W cm^–2 and a limiting current density of 4.46 A cm^–2 at high humidity, superior to the optimal characteristics of commercial GDLs under the experimental conditions set in this work.