An Overview of the Gas Diffusion Layer in Proton Exchange Membrane Fuel Cells: How Its Nano-structural Characteristics Affect Performance

Gas diffusion layer (GDL) is one of the critical components performing both as the operational as well as the support structure to membrane-electrode assembly (MEA) in the proton exchange membrane (PEM) fuel cell. The role of the GDL is very important in the PEM fuel cell to render it commercially applicable. Structural variations in the GDL can effect physico-chemical and mechanical properties and eventually power performance of the fuel cell. The optimization of the functional features of the GDL is possible just with comprehension the role of its key parameters such as structure, hydrophobicity/hydrophilicity, porosity, gas permeability, electrical conductivity. This paper presents an overview of effects of using nanosize materials to modify GDL structure. In addition, future prospects for new GDL developments are discussed.