空气自呼吸式直接甲醇燃料电池的温度特性

Operating Temperature Characteristics of Air-breathing Direct Methanol Fuel Cells

对空气自呼吸式(Air-breathing)直接甲醇燃料电池在开路状态下开路电压及电池温度与室温之间温差的变化,以及电流密度和甲醇溶液量对电池电压及温差的影响进行了实验研究。结果表明:放置时间达到30min,电池的各参数(开路电压、阳极温差、阴极温差、甲醇溶液温差)稳定,电池性能基本不变,便可以进行数据采集;为得到更准确的测量结果,可以适当地将放置时间增加到60min。电池温差随电流密度的增大而增大。当电流密度为20 mA/cm2时,温差先升高后降低;当电流密度为50 mA/cm2时,放电时间较短,并未出现温差降低的现象。在同一浓度下,甲醇溶液量越少,温差越高,电池性能越好,可以通过减小甲醇储液腔的容量来提高电池的性能。

The transient voltage and temperature of the passive air-breathing, liquid feed direct methanol fuel cell （DMFC） were investigated experimentally at different discharging current densities and methanol solution quantities. The results show that the cell performance become better with the longer waiting time, but become stable when all the parameters （open circuit voltage, anode temperature difference, cathode temperature difference and methanol solution temperature difference） come to steady. When the waiting time is longer than 30 min, with different concentration of methanol solution, all the parameters of cell are basically stable, and then the polarization data could be collected. In order to get a more accurate measurement results, the waiting time could be improved to 60 min properly. The temperature difference increases with an increase in discharging current density. At the low current density （20 mA/cm^2）, the temperature difference increases at first and decreases subsequently. At the high current density （50 mA/cm^2）, the temperature difference does not fall down because of the short discharging time. At the same concentration of methanol solution, with a smaller methanol solution quantity, the cell performance become better due to the higher temperature difference.