模拟车况下的质子交换膜燃料电池耐久性研究

Durability analysis of a proton exchange membrane fuel cell stack under simulated automobile working conditions

为了研究质子交换膜燃料电池(PEMFC)电堆在车载运行条件下的耐久性,介绍了3kW的PEMFC电堆在模拟车载运行工况条件下的1000h耐久性实验。通过分析不同工作电流条件下的电压、电堆极化曲线以及单电池电压分布等随时间的变化来考察PEMFC电堆在模拟车况条件下的性能衰减情况,并借助于红外探温测试和TEM表征来阐明电堆性能衰减机理。研究表明:在模拟车况条件下工作1000h后,质子交换膜燃料电池堆在0、35A及85A工作电流条件下的电压都衰减了6%左右,单电池电压平均衰减率分别为39.1、23.0μV/h和23.3μV/h;电堆中各单电池的性能衰减存在空间差异;质子交换膜的损伤导致的气体穿透是引起质子交换膜燃料电池堆性能衰减的主要因素。

In order to investigate the durability of PEMFC stack under automobile working conditions, the 1 000 h durability test under simulated automobile working conditions was reported. Through analyzing the voltage under different load, polarization curve of the stack and single cell voltage distribution in the stack as a function of time, performance degradation of the stack under the simulated automobile working conditions was investigated. At the end of the test, TEM and infrared thermograph were employed to elaborate the performance degradation mechanism of the stack. The results show that the stack voltages at 0,35 A and 85 A current degrade by 6%, and degradation rate of the open circuit voltage is the maximum among all kinds of voltages mentioned above. The voltage degradation of single cell is related with its position in the stack. Gas crossover induced by the crack or pinhole formation of the proton exchange membrane is the main source of performance degradation of the stack.