Nowadays high temperature polymer electrolyte fuel cells suffer from performance and long-term stability issues. Detailed understanding of the degradation effects is thus a key aspect for the improvement of this type of fuel cells. Degradation can be categorized into thermal, (electro-) chemical and mechanical effects. This paper focuses on the latter process, investigating two different types of membrane electrode assemblies by accelerated stress tests at high current densities in which, compared to common procedures, the device is driven at higher current densities between 0.6 - 1.0 A/cm~2. In addition to voltammetry and polarization curves, the assemblies are analyzed by electron microscopy methods and especially micro-computed tomography which allows a non-destructive investigation of the hidden interfaces within the MEA structure, giving a direct view on mechanical defects. Load cycling at high current densities revealed significant contributions to the degradation of the catalyst layer. But no influence on the membrane could be found.
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机译：如今，高温聚合物电解质燃料电池遭受性能和长期稳定性问题的困扰。因此，对降解效果的详细了解是改进此类燃料电池的关键方面。降解可分类为热，（电）化学和机械效应。本文着重于后一个过程，通过在高电流密度下通过加速应力测试研究两种不同类型的膜电极组件，与常规程序相比，该器件在0.6-1.0 A / cm〜2的更高电流密度下驱动。除伏安法和极化曲线外，还通过电子显微镜方法（尤其是微计算机断层扫描）对组件进行了分析，从而可以对MEA结构内的隐藏界面进行无损检查，从而直接查看机械缺陷。高电流密度下的负载循环显示出催化剂层降解的显着贡献。但是没有发现对膜的影响。
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