Effect of Carbon Content on the Physical Properties of Carbon Composite Gas Diffusion Layer in PEMFCs

Carbon composite gas diffusion layers (GDLs) containing carbon black and graphite for use in polymer electrolyte membrane fuel cells were prepared by a simple method. The physical properties of the carbon composite GDLs, such as air flux through a plane, porosity, pore diameter, pore area, and through-plane resistance, were investigated. Electrochemical measurements were carried out using a membrane electrolyte assembly prepared by hot-pressing a Nafion membrane and catalyst-coated GDLs. Graphite content was seen to have an effect on the physical properties of the carbon composite GDLs, and in turn, fuel cell performances. The effect of the variation in the physical properties of the carbon composite GDLs on fuel cell performance was investigated as a function of current density.