Dynamic impedance measurements of the Direct Methanol Fuel Cell cathode at various operating temperatures

This article presents results about the catalytic activity of the cathode in a Direct Methanol Fuel Cell (DMFC) across various operating temperatures. The Dynamic Electrochemical Impedance Spectroscopy (DEIS) technique coupled with a linear current scan was applied for this purpose. An equivalent model based on the thin-film flooded agglomerate model describing the cathode's behaviour was presented, and changes in its parameters were compared with the current load and different temperatures. Studies reveal shifts in cathodic kinetics with increasing load and temperature, alongside changes in resistance curves' slopes. The study identifies 351 K as the most optimal temperature, impacting parameters such as carbon layer resistance, diffusion parameter 1/Yo, and double electric layer capacitance significantly. Differences in slopes of resistance changes for different temperatures were also observed.