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

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.