Carbon Nanotube Modified Gas Diffusion Layer for PEM Fuel Cells

Carbon nano-materials were applied to the gas diffusion layers of PEMFC. Gas diffusion layers consist of gas diffusion medium (carbon cloth or carbon paper) and micro-layers. Carbon actives have been widely used for the micro-layers. Main functions of gas diffusion layers are distribution of reactants to the active site of electrode, management of water supplied and/or generated and enhancement of electrical contact between the electrode and the bipolar plates. In this work, nano-tubes are adopted to the micro-layer of gas diffusion layers. The micro-porous layer of the GDLs as seen under scanning electron microscope showed excellent surface morphology showing the reinforcement with nano-tubes and the surface homogeneity without any cracks. In this work, the 50% of carbon nano tube and 50% of carbon active contained micro-layer case showed the best I–V performance. By applying nano-materials, thinner micro-layers can be fabricated. This newly made micro-layer showed higher gas permeability and good electric conductivity with similar degree of water management as well as enhanced performance.