Abstract:

A mathematical model for a micro direct methanol fuel cell (μDMFC) anode was presented.In particular, the flow channels of the anode were simplified as regular porous media.The theoretical model of anode regions including flow channels was established based on the theory of porous media.In addition to the mass transport in the catalyst layer, the model considered methanol crossover caused by diffusion and electro-osmosis.The distribution of liquid saturation and the effect of anode flow rate on current density were investigated.The methanol concentration [JP+3]distribution in the anode was also calculated.Moreover, the characteristics of mass transport in the anode were analyzed.It was found that the methanol concentration decreased along the anode flow channels, and reduced evidently along the direction perpendicular to flow channels with an increase in overpotential.Methanol concentration distribution in the anode diffusion layer and catalyst layer showed similar variations.The methanol crossover flux decreased along the direction parallel to flow channels.A higher current density led to a lower methanol crossover flux.

Key words:

微型直接甲醇燃料电池, 阳极, 传质

摘要：

针对微型直接甲醇燃料电池，将阳极流场板简化为规则结构的多孔介质，运用多孔介质理论建立了包括流场板在内的阳极传输模型。模型考虑了阳极流道内液体饱和度沿流动方向的变化、催化层的厚度以及甲醇渗透，计算并讨论了阳极流道内液体饱和度的分布和流量对电池电流密度的影响，分析了阳极过电位对甲醇浓度分布和电池性能的影响以及质子交换膜内的传质特性。

关键词:

微型直接甲醇燃料电池, 阳极, 传质