Degradation characteristics of membrane electrode assembly under drive cycle test protocol
Degradation characteristics of membrane electrode assembly under drive cycle test protocol
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行驶循环测试方案下膜电极组件的降解特性
DOI：
10.1080/15435075.2019.1641712
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发表时间：
2019-07-14
影响因子：
3.3
通讯作者：
Tang, Yaping
中科院分区：
文献类型：
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作者：
Wang, Cheng;Zhao, Qing;Tang, Yaping
摘要质子交换膜燃料电池（PEMFC）的膜电极组件（MEA）的劣化和失效是决定其使用寿命的关键因素之一。为了评估MEA在车用燃料电池中的长期耐久性，本研究采用了加速技术，使用中国NERC燃料电池和氢技术开发的驱动循环测试协议。该协议包括启动/停止、怠速和加速，模拟了真实的汽车应用中的主要退化过程。经过900小时的加速测试，MEA的性能从初始的0.65 V下降到0.58 V@500 mA cm−2，下降超过10%，平均电压衰减率为70 μV h−1。为了研究降解的潜在机制，对MEA在900 h驱动循环试验前后进行了X射线光电光谱（XPS）、扫描电子显微镜（SEM）和能量色散X射线光谱（EDX）等事后分析。事后分析表明，质子交换膜燃料电池（PEMFC）出氢区电解质膜的减薄是导致PEMFC寿命终止的决定性因素，Pt催化剂的流失和MEA的微观结构损伤是PEMFC性能下降和稳定性恶化的决定性因素。
ABSTRACT One of the key factors determining the lifetime of proton exchange membrane fuel cell (PEMFC) is the degradation and eventually the failure of membrane electrode assembly (MEA). To assess the long-term durability of MEA in fuel cells for vehicular applicatoin, this study adopted the accelerating technique using drive cycle test protocol developed by Chinese NERC Fuel Cell & Hydrogen Technology. The protocol includes starts/stops, idling, and acceleration, simulating major degradation processes in real automobile application. After 900 h of accelerated test, MEA’s performance declined from the initial 0.65 V to 0.58 V@500 mA cm−2, dropping by more than 10% and giving an average voltage decay rate of 70 μV h−1. To examine the underlying mechanisms for the degradation, post-mortem analyses such as X-ray photoelectric spectroscopy (XPS), scanning electron microscopy (SEM) and energy dispersive X-Ray spectroscopy (EDX) were carried out for the MEA before and after 900 h drive cycle test. The post-mortem analyses indicate that the thinning of the electrolyte membrane at H2 outlet region is the decisive factor leading to the end-of-life of PEMFC, and the Pt catalysts loss and microstructural damage of MEA are the decisive factors for the performance degradation and stability deterioration of PEMFC.