质子交换膜燃料电池内电荷传递的数值模拟

为深入研究质子交换膜燃料电池内电荷传递的规律,发展了一个三维的单相流、非等温数学模型,模型考虑了电子在催化层和扩散层、质子在催化层和质子交换膜中的传递。通过计算得到了电池内电位和电流密度的空间分布,分析了不同电极结构参数下电流密度的分布和最终造成的性能差异。结果表明,欧姆电位的下降主要发生在膜相电位,而碳相电位的下降几乎可以忽略不计;电流密度在流道与集电极交界处出现＂火焰形＂累积效应;改变电池的结构对电池性能影响不大,应结合加工成本和电流密度分布综合考虑。

Numerical simulation of charge transport in proton exchange membrane fuel cells

A three-dimensional,single-phase,non-isothermal mathematical model is established to conduct further studies on the law of charge transport in proton exchange membrane fuel cells.The model takes into account electron transport through catalyst layer and gas diffusion layer,and proton transport through catalyst layer and proton exchange membrane.The spatial distribution of potential and current density is obtained by numerical computation.Then,the distribution of current density and the final performance for different electrode structure parameters are analyzed.The results indicate that membrane phase potential loss is the main part in ohm potential loss,however,the carbon phase potential loss is neglectable.The current density appears "torch shape" accumulation effect at the interface of channel and current collector.The cell performance is slightly affected by changing cell structure,which implies that changing cell structure should be comprehensively considered with machining cost and current density distribution.