阳极流场结构对直接甲醇燃料电池性能的影响

Effects of anode flow field structure on performance of direct methanol fuel cells

通过电化学方法和水平衡测试研究了阳极流场结构对DMFC阳极燃料甲醇和水的传质、迁移以及低电流密度区电池性能的影响。结果表明:阳极流场深度从1.2mm降至0.3mm,阳极极限电流密度IAlim和100mA/cm2时的甲醇渗透量Jcross分别增加49%和23%,电池的净水迁移系数α先降低后增加。在四种深度的阳极流场中(0.3,0.6,0.9,1.2mm),0.9mm深阳极流场电池的总效率最高且α最小,在低电流密度区具有较高的电压和较好的稳定性。

The effects of DMFC anode flow field on mass transportation, water transfer and cell performance were investigated in this study by electrochemical test and water balance analysis. Experimental results show that anode limiting current density IAlim and methanol crossover flux Jcross at 100 mA/cm2 increase by 49% and 23%, respectively, when the depth of anode channel decrease from 1.2 mm to 0.3 mm. The net water transfer coefficient a firstly decreases then increases as the depth decreases. Among 4 channel depths（0.3, 0.6, 0.9, 1.2 mm）, the cell with 0.9 mm depth flow field has both the highest cell efficiency and the lowest net water transfer coefficient, which lead to high cell voltage and stability at relatively low current density.