Entropy‐Driven Liquid Electrolytes for Lithium Batteries. Issue 17 (16th March 2023)

• Record Type: Journal Article
• Authors: Wang, Qidi; Zhao, Chenglong; Yao, Zhenpeng; Wang, Jianlin; Wu, Fangting; Kumar, Sai Govind Hari; Ganapathy, Swapna; Eustace, Stephen; Bai, Xuedong; Li, Baohua; Lu, Jun; Wagemaker, Marnix
• Is Part Of: Advanced materials. Volume 35:Issue 17(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-03-16
• Subjects: entropy‐driven electrolytes -- high‐entropy electrolytes -- lithium batteries -- temperature‐dependent electrolytes -- weak solvation structures; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202210677
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Developing liquid electrolytes with higher kinetics and enhanced interphase stability is one of the key challenges for lithium batteries. However, the poor solubility of lithium salts in solvents sets constraints that compromises the electrolyte properties. Here, it is shown that introducing multiple salts to form a high‐entropy solution, alters the solvation structure, which can be used to raise the solubility of specific salts and stabilize electrode–electrolyte interphases. The prepared high‐entropy electrolytes significantly enhance the cycling and rate performance of lithium batteries. For lithium‐metal anodes the reversibility exceeds 99%, which extends the cycle life of batteries even under aggressive cycling conditions. For commercial batteries, combining a graphite anode with a LiNi0.8 Co0.1 Mn0.1 O2 cathode, more than 1000 charge–discharge cycles are achieved while maintaining a capacity retention of more than 90%. These performance improvements with respect to regular electrolytes are rationalized by the unique features of the solvation structure in high‐entropy electrolytes. The weaker solvation interaction induced by the higher disorder results in improved lithium‐ion kinetics, and the altered solvation composition leads to stabilized interphases. Finally, the high‐entropy, induced by the presence of multiple salts, enables a decrease in melting temperature of the electrolytes and thus enables lower battery operation temperatures without changing the solvents. Abstract : High‐entropy alloys/materials are attracting significant attention in materials science, where the higher entropy facilitates the formation of solid‐solution phases. In this work, a general strategy is reported to enhance the solubility of specific salts in liquid electrolytes by introducing multiple salts to form a high‐entropy solution that assists in stabilizing the electrode–electrolyte interphases, that changes the solvation interactions, which can be used to improve battery performances.