Gas diffusion layers (GDLs) are crucial components for proton exchange membrane fuel cells (PEMFCs), since they modulate all relevant transport processes (fuel, reaction products, electricity, heat) [1 – 2].
Figure 1 shows a typical setup of a single cell PEMFC. It consists of two flowfields, two GDLs, catalyst layers and the proton exchange membrane (PEM). Gas diffusion layers act as an interface between the flow fields (structural cell parts, millimeter-size features) and the electrocatalysts (reaction layers, nanometer-size features), directing the fuel to the active sites while removing heat and reaction products and electrically wiring the reaction layers with the current collectors.
