Wang Chao, Xie Qihong, Wang Guotao, Lyu Yimeng, Wang Qianhui, Ma Xinxi, Wang Haobo, Guo Taolian, Wu Yutong, Han Jie
School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, China.
National Local Joint Engineering Laboratory for Advanced Textile Processing and Clean Production, Wuhan Textile University, Wuhan 430200, China.
Nano Lett. 2024 Oct 30;24(43):13796-13804. doi: 10.1021/acs.nanolett.4c04167. Epub 2024 Oct 14.
Aqueous zinc-bromine redox systems possess multiple merits for scalable energy storage. Applying bromine complexing agents shows effectiveness in alleviating the key challenge of ubiquitous crossover of reactive liquid bromine species, while the underlying microscopic mechanism requires a deep understanding to engineer better complexing electrochemistry. Herein, taking a series of quaternary ammonium ionic liquids (methylNBr, ethylNBr, propylNBr, and butylNBr) as a redox mediator model, optical monitoring was used to visualize the dynamic electrochemical behaviors, unveiling the ionic liquid-mediated polybromide electrochemistry with a distinct chain length effect. A longer chain length possesses a stronger electrostatic interaction in the complexing product to effectively capture Br. results reveal the liquid nature of the reversibly electrogenerated polybromide microdroplets in the butylNBr-added redox system, which promoted the Br/Br conversion kinetics and alleviated the self-discharge for improved battery performance. This work provides direct evidence and new insights into complexing electrochemistry for advancing Zn-Br batteries.
水系锌溴氧化还原体系在可扩展储能方面具有多种优点。应用溴络合剂在缓解活性液态溴物种普遍交叉这一关键挑战方面显示出有效性，而其潜在的微观机制需要深入理解，以便设计出更好的络合电化学。在此，以一系列季铵离子液体（甲基NBr、乙基NBr、丙基NBr和丁基NBr）作为氧化还原介质模型，利用光学监测来可视化动态电化学行为，揭示了具有独特链长效应的离子液体介导的多溴化物电化学。较长的链长在络合产物中具有更强的静电相互作用，能有效捕获Br。结果揭示了在添加丁基NBr的氧化还原体系中可逆电生成的多溴化物微滴的液体性质，这促进了Br/Br转化动力学并减轻了自放电，从而改善了电池性能。这项工作为推进锌溴电池的络合电化学提供了直接证据和新见解。
