船用质子交换膜燃料电池活化过程中的阻抗分析

Impedance Analysis of Marine Proton Exchange Membrane Fuel Cell During Activation

燃料电池是船舶动力装置电动化的理想选择,长期静置的燃料电池在重新投入使用前必须进行活化。很少有借助阻抗定量分析燃料电池活化过程中内部行为的研究,本文通过有效的等效电路模型分析了逐步加载活化过程中电池内各部分的阻抗。发现相关结论:传荷电阻占主导;阻抗谱上高频阻抗逐渐减小,由2.37 mΩ线性减小到1.66 mΩ,对应膜内磺酸基团氢化、质子电导率增大的过程;而低频弧半径则先减小后增大,五个电流段传荷电阻减小幅度分别为37%、13%、-27%、-57%,说明前期反应能垒逐渐降低,而后期则由于电流增大及产水导致界面气体浓度减小。

The fuel cell is ideal selection for electrification of ship power plant.The fuel cell in long term standing must be activated before put into use again.The interior behavior of the proton exchange membrane fuel cell during the activation process is seldom analyzed quantitatively by using the tool of impedance.In this paper,the resistances at different components of the fuel cell are investigated during the activation process,with the current loaded gradually,through an appropriate equivalent circuit model.It is found that the charge transfer resistance governs the activation course and that the high frequency resistance declines linearly from 2.37 to 1.66 mΩ,implying that the Nafion®membrane is hydrogenated and the proton conductivity increases gradually.It is unveiled that the radius of low-frequency arc decreases at first and then increases again,with the charge transfer resistance decreased 37%、13%、-27%、-57% respectively at the increasing currents.This is because the energy barrier for the oxygen reduction reaction declines at first and then the reactant concentration at the interface decreases owing to the increase of current density and water production.