Yu Weisheng, Zhang Zirui, Luo Fen, Li Xiaojiang, Duan Fanglin, Xu Yan, Liu Zhiru, Liang Xian, Wang Yaoming, Wu Liang, Xu Tongwen
Key Laboratory of Precision and Intelligent Chemistry, Department of Applied Chemistry, School of Chemistry and Material Science, University of Science and Technology of China, Hefei, 230026, China.
Nat Commun. 2024 Nov 25;15(1):10220. doi: 10.1038/s41467-024-54514-5.
Bipolar membrane electrolyzers present an attractive scenario for concurrently optimizing the pH environment required for paired electrode reactions. However, the practicalization of bipolar membranes for water electrolysis has been hindered by their sluggish water dissociation kinetics, poor mass transport, and insufficient interface durability. This study starts with numerical simulations and discloses the limiting factors of monopolar membrane layer engineering. On this foundation, we tailor flexible bipolar membranes (10 ∼ 40 µm) comprising anion and cation exchange layers with an identical poly(terphenyl alkylene) polymeric skeleton. Rapid mass transfer properties and high compatibility of the monopolar membrane layers endow the bipolar membrane with appreciable water dissociation efficiency and long-term stability. Incorporating the bipolar membrane into a flow-cell electrolyzer enables an ampere-level pure water electrolysis with a total voltage of 2.68 V at 1000 mA cm, increasing the energy efficiency to twice that of the state-of-the-art commercial BPM. Furthermore, the bipolar membrane realizes a durability of 1000 h at high current densities of 300 ∼ 500 mA cm with negligible performance decay.
双极膜电解槽为同时优化双电极反应所需的pH环境提供了一个有吸引力的方案。然而，双极膜在水电解中的实际应用受到其缓慢的水电离动力学、较差的传质性能和不足的界面耐久性的阻碍。本研究从数值模拟开始，揭示了单极膜层工程的限制因素。在此基础上，我们定制了柔性双极膜（10～40μm），其由具有相同聚（三联苯亚烷基）聚合物骨架的阴离子交换层和阳离子交换层组成。单极膜层的快速传质性能和高兼容性赋予双极膜可观的水电离效率和长期稳定性。将双极膜集成到流通池电解槽中，在1000 mA cm时可实现安培级纯水的电解，总电压为2.68 V，将能量效率提高到现有商用双极膜的两倍。此外，该双极膜在300～500 mA cm的高电流密度下实现了1000 h的耐久性，性能衰减可忽略不计。
