The paper presents the obtained measurement and analysis results of the accelerated stress test protocols consisting of voltage cycling, designed to target electrocatalyst degradation, with the intentional recovery periods (so‐called soak time steps) every 2,500 voltage cycles on an already conditioned 50 cm² (single) fuel cell provided by ElringKlinger. Before and after every intentional stop, a series of diagnostic methods (polarization curves, electrochemical impedance spectroscopy, cyclic voltammetry, linear sweep voltammetry) were performed. During the conducted durability test, different shutdown procedures, as well as different duration of the soak time period were tested with their impact on performance recovery phenomenon. The results suggest that cause of the reversible degradation could be accumulated water within the cell and/or presence of oxygen within the catalyst layer leading to formation of platinum oxides on the catalyst surface. The prolonged soak time step reduces recovery effect, while rapid reduction of the cell temperature with ice proved to be counterproductive for performance recovery. Shutdown procedure without shortly‐connected resistor has shown no effect on recovery. Shutdown procedure without nitrogen purge proved to be the most effective for performance recovery.

中文翻译：

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关机程序对质子交换膜燃料电池恢复现象的影响

本文介绍了由电压循环组成的加速应力测试协议的测量结果和分析结果，旨在针对电催化剂的降解，在经过调节的50 cm ²上每2500个电压周期有意的恢复时间（所谓的浸泡时间步长）。（单个）燃料电池，由ElringKlinger提供。在每次有意停止之前和之后，都执行了一系列诊断方法（极化曲线，电化学阻抗谱，循环伏安法，线性扫描伏安法）。在进行的耐久性测试中，测试了不同的关机程序以及浸泡时间的不同持续时间，它们对性能恢复现象的影响。结果表明，可逆降解的原因可能是电池内积水和/或催化剂层内存在氧气，从而导致在催化剂表面形成氧化铂。延长的浸泡时间会降低恢复效果，而用冰迅速降低电池温度被证明对恢复性能起反作用。没有短接电阻的关机程序对恢复没有影响。事实证明，不进行氮气吹扫的关机程序对于恢复性能最为有效。