Membrane degradation is one of the most important factors limiting lifetime of PEMWE stacks, and imposes severe purity demands in water fed into PEMWE electrolyzers. Therefore, damage to the membrane is one of the major limitations that impede widespread implementation of PEM technology to produce green hydrogen. Several membrane degradation test procedures have been discussed in literature. In this work, the loss of membrane material is related to the operating conditions of a 4-cell PEMWE stack through measurements of the fluoride concentration of the water output from the electrolyzer, both at the cathode and at the anode, at different temperatures (25 and 40 °C), flow rates (20, 25 and 30 mL/min for a nominal water consumption of 2 mL/min) and operating loads (3 different voltages and currents ranging from the nominal 8 V and 0.26 A/cm to 6.8 V and 0.05 A/cm). Conductivity of excess water collected at electrolyzer outlets is shown to be linearly related to its fluoride content under a wide range of electrolyzer operating conditions, including constant and dynamical loads. Therefore, knowing the on-line conductivity at both the anode and cathode can provide an assessment of the condition and lifetime of the membrane. The study shows that different workloads affect the lifetime of the electrolyzer and can be observed by in situ and ongoing monitoring of the conductivity of both the anode and cathode.

中文翻译：

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使用在线电导率测量作为 PEMWE 中全氟磺酸膜降解的诊断工具

膜降解是限制 PEMWE 电堆寿命的最重要因素之一，并对进入 PEMWE 电解槽的水提出了严格的纯度要求。因此，膜的损坏是阻碍质子交换膜技术广泛实施生产绿色氢气的主要限制之一。文献中已经讨论了几种膜降解测试程序。在这项工作中，通过测量不同温度下阴极和阳极电解槽输出水的氟化物浓度，膜材料的损失与 4 单元 PEMWE 堆栈的运行条件相关（25和 40 °C）、流量（标称耗水量为 2 mL/min 时为 20、25 和 30 mL/min）和工作负载（3 种不同的电压和电流，范围从标称 8 V 和 0.26 A/cm 到 6.8 V 和 0.05 A/cm）。在电解槽出口处收集的过量水的电导率显示，在各种电解槽操作条件（包括恒定负载和动态负载）下，其氟化物含量呈线性相关。因此，了解阳极和阴极的在线电导率可以评估膜的状况和寿命。研究表明，不同的工作负载会影响电解槽的使用寿命，并且可以通过对阳极和阴极的电导率进行现场和持续监测来观察。