Su Long, Lu Fei, Li Yanrui, Li Xia, Chen Liangdan, Gao Yanan, Zheng Liqiang, Gao Xinpei
Key Laboratory of Colloid and Interface Chemistry, Shandong University, Jinan, 250100, P. R. China.
Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources, School of Chemical Engineering and Technology, Hainan University, Haikou, 570228, P. R. China.
ChemSusChem. 2023 Jul 21;16(14):e202300285. doi: 10.1002/cssc.202300285. Epub 2023 Jun 9.
Despite their intrinsic safety and environmental friendliness, typical aqueous Zn-ion rechargeable batteries have been struggling with poor reversibility and electrochemical stability. Hydrated eutectic electrolytes (HEEs) have been attracting extensive attention due to their appealing features of high designability and superior performances over typical aqueous electrolytes. However, an in-depth understanding of unique microstructure in HEEs and the ensuing superior performances remains obscure, limiting the development of enhanced electrolytes. Herein, we demonstrate a distinct evolution path of Zn-ion species from aqueous to superior hydrated eutectic electrolytes, which experience a special transition state enriched with H-bonds between eutectic molecules. Complementary with the well-studied reorganized solvation structure induced by short-ranged salt-solvent interaction, long-range solvent-solvent interactions arising from the H-bond reorganizes the extended electrolyte microstructure, which in turn influences the cation diffusion mechanisms and interfacial reaction kinetics. Overall, we highlight the importance of ion species microstructural evolution in the rational design of superior aqueous electrolytes.
尽管典型的水系锌离子可充电电池具有内在安全性和环境友好性，但它们一直难以解决可逆性差和电化学稳定性问题。水合共晶电解质（HEEs）因其具有高度可设计性以及相较于典型水系电解质的卓越性能等吸引人的特性而备受广泛关注。然而，对HEEs中独特微观结构及其所带来的卓越性能的深入理解仍不清晰，这限制了高性能电解质的发展。在此，我们展示了锌离子物种从水系电解质到卓越水合共晶电解质的独特演变路径，它们经历了一个富含共晶分子间氢键的特殊过渡态。与由短程盐 - 溶剂相互作用诱导的已被充分研究的重组溶剂化结构相辅相成，由氢键产生的长程溶剂 - 溶剂相互作用重组了扩展的电解质微观结构，进而影响阳离子扩散机制和界面反应动力学。总体而言，我们强调了离子物种微观结构演变在高性能水系电解质合理设计中的重要性。
