Characterization of Carbon Nanofiber-Based Fuel Cell Electrodes

Fuel cell electrodes with silver and platinum as catalyst material supported on carbon nanofibers (CNFs) were investigated with an alkaline electrolyte. The advantageous chemical properties, the large surface area and the high electric conductivity of the nanostructured material make them an interesting candidate for an application in fuel cell electrodes. The electrodes prepared by a sedimentation process consist of CNFs in the active layer as well as in the gas diffusion layer. PTFE was used as binder material and hydrophobic agent to prevent the electrode from being flooded by the electrolyte. The electrodes were electrochemically investigated by measuring polarization curves and impedance spectroscopy in half cell tests to show the performance for the cathode with Pt and Ag supported CNF. Furthermore, the electrodes were investigated with SEM to correlate the electrochemical behavior to the structure of the active layer and the gas diffusion layer.