PEMFCs的膜及阴极催化层数值模拟

MEMBRANE AND CATHODE CATALYST LAYER NUMERICAL SIMULATION OF PEMFCS

本文提出了一个质子交换膜燃料电池的膜和阴极催化层的一维非稳态数学模型,模型考虑了电化学反应及反应中的传质过程。本文结合算例分析了燃料电池膜及阴极催化层的性能,结果能验证燃料电池内阻理论。论文结果表明:(1)随着输出电流密度的增大,氧浓度分布不均匀性增大; (2)阴极催化层厚度减小,可提高电池输出电压; (3)电池进口处氧气摩尔浓度增大,可增加电池的输出电压。

A transient, one-dimension numerical simulation approach is presented to evaluation proton exchange membrane fuel cells (PEMFCs). The model is applied to simulate the membrane and the cathodic catalyst layer of a PEMFC. The numerical model is created using an advanced computational fluid dynamics (CFD) technique, combines the electrochemistry process and mass transfer in the PEMFC. It is developed to predict transient behaviors of a PEMFC. The computer simulation result is validated by electrode polarization theory. The simulative results reveal that: (1) At high current densities, the back portion of the cathodic catalyst layer (near xlc=0) is depleted of the dissolved-oxygen. (2) When the thickness of cathodic catalyst layer is decreased, the electrode potential is increase. (3) When the oxygen mole ratio in the fuel cell's entrance is increased, the electrode potential is increase, too.