Design, fabrication and testing of an air-breathing micro direct methanol fuel cell with compound anode flow field

An air-breathing micro direct methanol fuel cell (mu DMFC) with a compound anode flow field structure (composed of the parallel flow field and the perforated flow field) is designed, fabricated and tested. To better analyze the effect of the compound anode flow field on the mass transfer of methanol, the compound flow field with different open ratios (ratio of exposure area to total area) and thicknesses of current collectors is modeled and simulated. Micro process technologies are employed to fabricate the end plates and current collectors. The performances of the mu DMFC with a compound anode flow field are measured under various operating parameters. Both the modeled and the experimental results show that, comparing the conventional parallel flow field, the compound one can enhance the mass transfer resistance of methanol from the flow field to the anode diffusion layer. The results also indicate that the mu DMFC with an anode open ratio of 40% and a thickness of 300 mu m has the optimal performance under the 7 M methanol which is three to four times higher than conventional flow fields. Finally, a 2 h stability test of the mu DMFC is performed with a methanol concentration of 7 M and a flow velocity of 0.1 ml min(-1). The results indicate that the mu DMFC can work steadily with high methanol concentration.