直接甲醇燃料电池管状阴极的制备与性能

Preparation and cell performance of tubular cathode for direct methanol fuel cell

以管状金属钛网为支撑体,采用浸涂工艺在其外表面依次制备了气体扩散层、Pt/C催化层和Nafion膜,制得管状阴极,并分析了影响电池性能的因素.研究结果表明,采用浆液浸涂工艺制备的阴极气体扩散层与催化层,均具有有利于气体传质和电化学反应的多孔结构.随着阴极催化剂载量的增加,单电池的性能也逐渐提高.当Pt载量为4.3 mg/cm2时,常温下以空气作为氧化剂,电池功率密度峰值约为12.3 mW/cm2,而同样的电池,在60℃下以氧气作为氧化剂,则可以达到40.0 mW/cm2,这表明温度和氧化剂种类与催化剂载量一样,是影响电池性能的重要因素.电池经约100 h工作时间后进行的等电压放电试验结果表明,该管状Ti基阴极的电化学稳定性优良.

A tubular cathode was prepared by subsequently dip-coating the gas diffusion layer,Pt/C catalyst layer and Nafion membrane on the outside of the tubular Ti mesh.The single direct methanol fuel cell composed of the above electrodes was discussed under normal pressure,and the factors that affected the cell performance were discussed.The results show that the diffusion layer and catalyst layer prepared by dip-coating have mesoporous microstructure which is beneficial to mass transport.With catalyst loa-ding increasing,the cell performance improves.When the Pt loading on cathode is 4.3 mg/cm2,the power density of DMFC reaches 12.3 mW/cm2 at room temperature by using air as the cathode feed.With the oxygen as the cathode feed,the power density of DMFC can reach 40.0 mW/cm2 at 60 ℃.This indicates that the temperature and oxidant type are as important as the cathode catalyst loading.The stability test of the cell after working for 100 h shows that the tubular cathode has a perfect stability.