Xie Hongliang, Cheng Haoran, Kumar Pushpendra, Wang Yuqi, Liang Honghong, Cai Tao, Zhao Fei, Cao Zhen, Cavallo Luigi, Ma Zheng, Li Qian, Ming Jun
State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China.
School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China.
ACS Nano. 2024 Aug 20;18(33):22503-22517. doi: 10.1021/acsnano.4c07986. Epub 2024 Aug 7.
Electrolyte solvation chemistry regulated by lithium salts, solvents, and additives has garnered significant attention since it is the most effective strategy for designing high-performance electrolytes in lithium-ion batteries (LIBs). However, achieving a delicate balance is a persistent challenge, given that excessively strong or weak Li-solvent coordination markedly undermines electrolyte properties, including thermodynamic redox stability and Li-desolvation kinetics, limiting the practical applications. Herein, we elucidate the crucial influence of solvent-solvent interactions in modulating the Li-solvation structure to enhance electrolyte thermodynamic and kinetic properties. As a paradigm, by combining strongly coordinated propylene carbonate (PC) with weakly coordinated cyclopentylmethyl ether (CPME), we identified intermolecular interactions between PC and CPME using H-H correlation spectroscopy. Experimental and computational findings underscore the crucial role of solvent-solvent interactions in regulating Li-solvent/anion interactions, which can enhance both the thermodynamic (i.e., antireduction capability) and kinetic (i.e., Li-desolvation process) aspects of electrolytes. Additionally, we introduced an interfacial model to reveal the intricate relationship between solvent-solvent interactions, electrolyte properties, and electrode interfacial behaviors at a molecular scale. This study provides valuable insights into the critical impact of solvent-solvent interactions on electrolyte properties, which are pivotal for guiding future efforts in functionalized electrolyte engineering for metal-ion batteries.
由锂盐、溶剂和添加剂调控的电解质溶剂化化学已备受关注，因为这是设计锂离子电池（LIBs）高性能电解质的最有效策略。然而，实现精确平衡一直是个挑战，因为过强或过弱的锂-溶剂配位会显著破坏电解质性能，包括热力学氧化还原稳定性和锂去溶剂化动力学，限制了实际应用。在此，我们阐明了溶剂-溶剂相互作用在调节锂溶剂化结构以增强电解质热力学和动力学性能方面的关键影响。作为一个范例，通过将强配位的碳酸丙烯酯（PC）与弱配位的环戊基甲基醚（CPME）相结合，我们利用H-H相关光谱确定了PC和CPME之间的分子间相互作用。实验和计算结果强调了溶剂-溶剂相互作用在调节锂-溶剂/阴离子相互作用中的关键作用，这可以增强电解质的热力学（即抗还原能力）和动力学（即锂去溶剂化过程）方面。此外，我们引入了一个界面模型，以揭示溶剂-溶剂相互作用、电解质性能和电极界面行为在分子尺度上的复杂关系。这项研究为溶剂-溶剂相互作用对电解质性能的关键影响提供了有价值的见解，这对于指导未来金属离子电池功能化电解质工程的努力至关重要。
