Generation performance of gas-feed direct methanol fuel cell

The modification effect of Nafion on the generation performance at different temperatures and methanol concentrations was investigated. The direct methanol fuel cell performances and electrochemical properties of the DMFC system using as-received Nafion 117, a modified Nation membrane, and using the Nafion 117 MEA preparation by spray treatment on the surface of each catalyst layer for conductivity improvement. The open circuit voltage using the modified Nation membrane was higher than that using Nafion 117 at the cell temperature of 343-383 K and methanol concentration of 1.5-10 kmol/m(3). The spray treatment of MEA was effective and improved the short circuit current up to 461 mA/cm(2) at a(.)5kmol/m(3) methanol concentration in comparison with no treatment of MEA because of the low interfacial resistance. The power density of 75 mW/cm(2) (no treatment Nafion 117 MEA:40 mW/cm(2)) was obtained. The method of the spray treatment was found to be very effective for the DMFC system. The cell performance of Nafion117 MEA increased with the methanol concentration because of the reduction of the concentration overvoltage.