Development of a high-performance fuel cell with a novel electrode structure

采用毛细管探针原位质谱分析了DMFC惰性电极结构中阳极气层中气体组分及其压力。在此基础上研究了电极上的反应产物及其产率和膜传质率。通过平衡计算发现，气相层甲醇的蒸气压对应于液体进料DMFC中使用的甲醇浓度。中间产物中主要成分甲酸甲酯的产率与气相层甲醇蒸气压/水蒸气压之比的次幂成正比。但与CO_2的产率相比，中间产物的形成在能量转换效率中可以忽略不计。通过在阴极外放置疏水多孔膜，使其与阴极表面保持最佳距离，从而增加阴极的水通量，从而提高输出功率。

Gas components and their pressures in the anode gas layer formed in the noble electrode structure of a DMFC was analyzed by using in-situ mass spectroscopy with a capillary probe. Reaction products at the electrode and their production rates as well as their mass transfer rates crossing the membrane were investigated based on the measurements. It was revealed that the vapor pressure of methanol in the gas layer corresponds to the methanol concentration used in a liquid feed DMFC from the equilibrium calculation. Production rate of methyl-formate, as a main component of the intermediate-product, was proportional to the second power to the ratio of methanol vapor pressure/water vapor pressure in the gas layer. However, the formation of the intermediate products could be neglected in the energy conversion efficiency because of the too small production rates comparing with that of CO_2. The power out put was increased by increasing the water flux from the cathode by putting a hydrophobic porous membrane out side the cathode by keeping an optimum distance from the cathode surface.