Hydrogen production by proton exchange membrane water electrolysis (PEMWE) is considered a pivotal technology for renewable energy storage, utilization and conversion. In this study, based on one-year output data of photovoltaic (PV) and wind power (WP) generation in North China region, a K-means clustering algorithm was employed to extract the typical working conditions of PV and WP. The accelerated stress test (AST) protocols applicable to PEMWE stacks were proposed. Using the cell voltage monitoring (CVM) and cell temperature monitoring (CTM) devices, the voltage-temperature variations and transient response characteristics of a 10-cell PEMWE stack were experimentally investigated under steady-state, PV-AST and WP-AST conditions. Evaluation indexes were introduced to quantify the electrical-thermal consistency during 100-hour of continuous operation. The results indicate that stack performance degradation is relatively modest under steady-state testing, while significant performance degradation and electrical-thermal consistency deterioration are observed under AST fluctuating conditions. Electrochemical analysis using Electrochemical Impedance Spectroscopy-Distribution of Relaxation Times (EIS-DRT) revealed increased impedance in various electrochemical processes after 100 h of continuous testing, with more pronounced hindrance observed under AST conditions. Additionally, micro-morphological characterization identified evident material defects and degradation are witnessed in the catalyst coated membrane (CCM) after AST conditions, indicating severer cell failure due to frequent start-up/shut-down cycles and power fluctuations. These efforts contribute to clarify the electrical-thermal-electrochemical characteristics and degradation mechanisms of PEMWE stacks during long-term operations powered by renewable energy.

中文翻译：

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在由可再生能源驱动的加速应力测试协议中了解 PEMWE 堆栈的电-热-电化学见解


质子交换膜水电解 （PEMWE） 制氢被认为是可再生能源储存、利用和转换的关键技术。本研究基于华北地区光伏和风电发电 （WP） 一年的输出数据，采用 K-means 聚类算法提取光伏和风电的典型工况。提出了适用于 PEMWE 堆栈的加速压力测试 （AST） 协议。使用电池电压监测 （CVM） 和电池温度监测 （CTM） 器件，在稳态、PV-AST 和 WP-AST 条件下实验研究了 10 节电池 PEMWE 堆栈的电压-温度变化和瞬态响应特性。引入评价指标来量化连续运行 100 小时的电热一致性。结果表明，在稳态测试下，电堆性能下降相对较小，而在 AST 波动条件下观察到显著的性能下降和电热一致性恶化。使用电化学阻抗谱-弛豫时间分布 （EIS-DRT） 的电化学分析显示，在连续测试 100 小时后，各种电化学过程中的阻抗增加，在 AST 条件下观察到更明显的阻碍。此外，微观形态学表征确定了在 AST 条件后催化剂涂层膜 （CCM） 中明显的材料缺陷和降解，表明由于频繁的启动/关闭循环和功率波动，电池故障更严重。 这些努力有助于阐明 PEMWE 电堆在由可再生能源供电的长期运行期间的电-热-电化学特性和降解机制。