PEMFC电堆加速老化测试及性能恢复现象分析

Accelerated Aging Test and Performance Recovery Analysis of PEMFC Stack

摘要:

对自制kW级的质子交换膜燃料电池（PEMFC）电堆在车载工况下进行了加速老化测试（ADT）.结合极化曲线、交流阻抗谱（EIS）及电压时间曲线考察了PEMFC的性能变化.通过扫描电镜（SEM）和透射电镜（TEM）对试验前后的膜电极进行非现场表征对比分析，解释PEMFC性能衰退的原因.结果表明：603 h车载工况加速老化试验后，电堆最大功率下降21.6%，同时电堆在休整之后存在明显的性能恢复现象；常相位角元件值和法拉第阻抗值在电堆休整后减小，说明催化剂活性有所恢复，电堆内部水热环境在冷机启动后达到较理想状态.

Abstract:

Accelerated degradation test (ADT) of a homemade kW level proton exchange membrane fuel cell (PEMFC) stack was conducted under drive cycle. The stack performance degradation was observed, as expected, with the help of polarization curve, electrochemical impedance spectrum (EIS) and V t curve. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were applied to characterize the fresh and post experiment membrane electrode assemblies. The results show that after 603 h ADT, the max power output drops 21.6%. Meanwhile, the phenomenon of recoverable degradation after “rest” was preliminarily analyzed by virtue of EIS and equivalent circuit analysis. It is found that the values of constant phase angle element and faradic impedance get partly recovered, which implies that the recovery of the activity of catalyst and the hydrothermal environment in fuel cell reach an ideal condition before next cold start.