Investigations on degradation of the long-term proton exchange membrane water electrolysis stack
Investigations on degradation of the long-term proton exchange membrane water electrolysis stack
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质子交换膜水电解堆长期降解研究
DOI：
10.1016/j.jpowsour.2014.05.117
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发表时间：
2014-12-01
影响因子：
9.2
通讯作者：
Yi, Baolian
中科院分区：
文献类型：
--
作者：
Sun, Shucheng;Shao, Zhigang;Yi, Baolian
开发了一个9单元质子交换膜（PEM）水电解堆栈，并对其进行了7800小时的测试。测量了每个单元35.5 μ V h（-1）的平均降解率。对栈的第4层MEA进行了离线研究和表征。电化学阻抗谱（EIS）表明，电池的电荷转移电阻和离子电阻都增加了。线性扫描（LSV）显示膜的氢交叉率略有增加。电子探针x射线微分析（EPMA）进一步表明，Ca、Cu和Fe元素分布在催化剂包覆膜（CCMs）的膜层和催化剂层中。阳离子占据了Nation聚合物电解质在催化剂层和膜中的离子交换位点，导致阳极和阴极过电位升高。金属杂质主要来源于给水和电解装置的部件。幸运的是，这种降解是可逆的，使用0.5 M H2SO4几乎可以恢复到初始性能。这表明运行7800 h的堆栈性能下降主要是由可恢复的污染引起的。(C) 2014 Elsevier B.V.版权所有
A 9-cell proton exchange membrane (PEM) water electrolysis stack is developed and tested for 7800 h. The average degradation rate of 35.5 mu V h(-1) per cell is measured. The 4th MEA of the stack is offline investigated and characterized. The electrochemical impedance spectroscopy (EIS) shows that the charge transfer resistance and ionic resistance of the cell both increase. The linear sweep scan (LSV) shows the hydrogen crossover rate of the membrane has slight increase. The electron probe X-ray microanalyze (EPMA) illustrates further that Ca, Cu and Fe elements distribute in the membrane and catalyst layers of the catalyst-coated membranes (CCMs). The cations occupy the ion exchange sites of the Nation polymer electrolyte in the catalyst layers and membrane, which results in the increase in the anode and the cathode overpotentials. The metallic impurities originate mainly from the feed water and the components of the electrolysis unit. Fortunately, the degradation was reversible and can be almost recovered to the initial performance by using 0.5 M H2SO4. This indicates the performance degradation of the stack running 7800 h is mainly caused by a recoverable contamination. (C) 2014 Elsevier B.V. All rights reserved.