操作条件对质子交换膜燃料电池电化学阻抗动态行为的影响

应用交流阻抗谱法（electrochemical impedance spectroscopy，EIS）研究温度、湿度和阴、阳极过量系数4种操作条件对质子交换膜燃料电池（proton exchange membrane fuel cell，PEMFC）电化学阻抗的影响，并应用复合阻容并联等效电路对实验结果进行等效拟合。实验结果表明，PEMFC单电池的电流密度为1400 mA/cm²时，阴极过量系数对PEMFC单电池高频阻抗的影响最大，温度和湿度次之，阳极过量系数影响最小；不同操作条件的改变对高频阻抗谱中的欧姆阻抗的影响非常小，主要通过影响阴阳极法拉第阻抗来影响PEMFC单电池的输出性能；等效结果和实验结果在不同频率段的阻抗表现出一致的变化规律，各阻抗的误差值能够控制在2mΩ以内，可以有效地等效替代实验结果。

Effects of operating conditions on PEMFC dynamic behavior by EIS

In this paper, the effect of four operating conditions on the electrochemical impedance of the proton exchange membrane fuel cell(PEMFC) was investigated by using the electrochemical impedance spectroscopy (EIS), which included temperature, humidity, cathode and anode stoichiometry. The compound resistance-capacitance parallel equivalent circuit was used to fit the experimental results. The experimental results showed that the high frequency impedance of cathode stoichiometry affected PEMFC single cell most, followed by the temperature, humidification temperature, and anode stoichiometry when the current density of PEMFC single cell was 1400mA/cm².The influence of different operating conditions on the ohmic impedance in high frequency impedance spectrum was not obvious, which mainly changed the output performance of the PEMFC cell by affecting the anode and cathode faraday impedance. The equivalent results and the experimental results showed consistent changing rule of impedance in different frequency bands, the varaition of each impedance can be controlled within 2mΩ, which can effectively replace the experimental results.