Effects of microporous layer preparation on the performance of a direct methanol fuel cell

The effects of two different microporous layer (MPL) preparation methods, including a heated-spraying method and a scraping method, on the performance of a direct methanol fuel cell (DMFC) were investigated. The experimental results indicated the cell with the new MPL had a higher mass transfer rate of oxygen and better performance than that of the conventional MPL. Scanning electron microscopy (SEM) images showed that there were more cracks and voids on the surface of the new MPL than that of the conventional MPL. The cathode and anode polarization curves exhibited that the cell with conventional MPL decreased the cell performance due to the difficulty for mass transport. Electrochemical impedance spectra (EIS) analysis further demonstrated that the improved performance of the cell with new MPL was attributed to the enhanced oxygen transport as the result of the reduced mass transfer resistance in the fuel cell system.