Performance of special-shaped direct methanol fuel cell with sol-gel flux phase

A special-shaped tubular cathode was prepared by using graphite-doped mesocarbon microbeads (MCMB/G) through dip coating the gas diffusion layer and catalyst layer and wrapping the sintering tube with the Nafion membrane subsequently. The sol-gel flux phase was prepared by sol-gel technology. The impedance of the special-shaped direct methanol fuel cell with sol-gel flux phase was investigated; the effects of tube wall thickness, gas diffusion layer loading, working temperature, and sol viscosity on the cell polarization performance were examined. The results showed that the impedance of the special-shaped cell was much higher than that of the traditional flat electrode; however, an obvious decrease in impedance was observed after activation. The cell performance improved with the decrease in sol viscosity and with the increase in working temperature. The cell performs well when the wall thickness is 1.3 mm and the gas diffusion layer loading is 3.5 mg/cm2.