Membrane electrode assembly degradation under idle conditions via unsymmetrical reactant relative humidity cycling
Membrane electrode assembly degradation under idle conditions via unsymmetrical reactant relative humidity cycling
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DOI：
10.1016/j.jpowsour.2012.01.133
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发表时间：
2012-06-01
影响因子：
9.2
通讯作者：
Wang, Haijiang
中科院分区：
文献类型：
--
作者：
Vengatesan, S.;Panha, Karachakorn;Wang, Haijiang
本研究的目的是通过反应物相对湿度 (RH) 循环来研究加速测试条件下的膜电极组件 (MEA) 失效模式。在这项研究中，阳极和阴极以不对称的方式经历相对湿度循环，电池在耐久性测试期间以最小“空闲”电流运行。定期监测电池性能，降解曲线显示阳极和阴极诱导的相对湿度循环模式存在差异。阳极相对湿度循环对 MEA 降解的影响比阴极相对湿度循环更显着。交流阻抗和 H-2 交叉测量等电化学诊断测试方法更详细地揭示了降解现象。阳极相对湿度的氟化物释放数据红外成像结果显示，膜中存在变薄和热点针孔，并且通过扫描电子显微镜发现阳极 RH 循环电池的寿命比阴极 RH 循环电池的寿命短，这凸显了阳极加湿对 MEA 耐久性的重要性。 (C) 2012 Elsevier B.V. 保留所有权利。
The objective of this study is to investigate membrane electrode assembly (MEA) failure modes under accelerated test conditions via reactant relative humidity (RH) cycling. In this study, the anode and cathode underwent RH cycling in an unsymmetrical manner and the cell was run at a minimal ''idle" current during endurance testing. The cell performance was monitored periodically and the degradation curve showed a difference in the anode and cathode induced RH cycling modes. Anode RH cycling had a more pronounced effect on MEA degradation than cathode RH cycling. Electrochemical diagnostic testing methods such as AC impedance and H-2 crossover measurements revealed the degradation phenomena in more detail. The fluoride release data of the anode RH cycling cell showed a sudden increase in fluoride rate within a short period of endurance testing. The infrared imaging results revealed thinning and hotspot pinholes in the membrane, and ionomer delamination from the PTFE reinforcement layer was identified by scanning electron microscopy. The anode RH cycling cell had a shorter lifespan than the cell with cathode RH cycling, highlighting the significance of anode humidification for MEA durability. (C) 2012 Elsevier B.V. All rights reserved.