Xie Junpeng, Lin Dewu, Lei Hang, Wu Shuilin, Li Jinliang, Mai Wenjie, Wang Pengfei, Hong Guo, Zhang Wenjun
Department of Materials Science and Engineering & Center of Super-Diamond and Advanced Films, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, 999077, China.
Siyuan Laboratory, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Materials, Department of Physics, Jinan University, Guangzhou, 510632, China.
Adv Mater. 2024 Apr;36(17):e2306508. doi: 10.1002/adma.202306508. Epub 2023 Nov 28.
Aqueous batteries are promising alternatives to non-aqueous lithium-ion batteries due to their safety, environmental impact, and cost-effectiveness. However, their energy density is limited by the narrow electrochemical stability window (ESW) of water. The "Water-in-salts" (WIS) strategy is an effective method to broaden the ESW by reducing the "free water" in the electrolyte, but the drawbacks (high cost, high viscosity, poor low-temperature performance, etc.) also compromise these inherent superiorities. In this review, electrolyte and interphase engineering of aqueous batteries to overcome the drawbacks of the WIS strategy are summarized, including the developments of electrolytes, electrode-electrolyte interphases, and electrodes. First, the main challenges of aqueous batteries and the problems of the WIS strategy are comprehensively introduced. Second, the electrochemical functions of various electrolyte components (e.g., additives and solvents) are summarized and compared. Gel electrolytes are also investigated as a special form of electrolyte. Third, the formation and modification of the electrolyte-induced interphase on the electrode are discussed. Specifically, the modification and contribution of electrode materials toward improving the WIS strategy are also introduced. Finally, the challenges of aqueous batteries and the prospects of electrolyte and interphase engineering beyond the WIS strategy are outlined for the practical applications of aqueous batteries.
水系电池因其安全性、环境影响和成本效益，是有望替代非水系锂离子电池的选择。然而，其能量密度受限于水的狭窄电化学稳定窗口（ESW）。“盐包水”（WIS）策略是通过减少电解质中的“自由水”来拓宽ESW的有效方法，但缺点（高成本、高粘度、低温性能差等）也削弱了这些固有的优势。在这篇综述中，总结了水系电池的电解质和界面工程以克服WIS策略的缺点，包括电解质、电极-电解质界面和电极的发展。首先，全面介绍了水系电池的主要挑战和WIS策略的问题。其次，总结并比较了各种电解质成分（如添加剂和溶剂）的电化学功能。凝胶电解质也作为一种特殊形式的电解质进行了研究。第三，讨论了电极上电解质诱导界面的形成和改性。具体而言，还介绍了电极材料对改进WIS策略的改性和贡献。最后，概述了水系电池的挑战以及超越WIS策略的电解质和界面工程在水系电池实际应用中的前景。
