Xie Lin, Liang Yihong, Wang Jialin, Wu Wanbao, Zhang Jichuan, Zhang Jiaheng
Sauvage Laboratory for Smart Materials, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China.
School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China.
Small. 2024 Dec;20(49):e2407484. doi: 10.1002/smll.202407484. Epub 2024 Oct 6.
Proper design of the solvation structure is crucial for the development of lithium metal batteries (LMBs). In this paper, the use of 1,2-Dimethoxyethane (DME) as a non-solvating cosolvent in amide-based eutectic electrolytes is proposed to address challenges related to high viscosity, high polarization, and low conductivity, thus enhancing the compatibility with lithium metal anodes. Through physical characterization combined with simulation calculations the existence of a weak interaction between DME and anions is confirmed, which promotes the dissociation of lithium salts and increases the Li transference number and diffusion coefficient, thus improving the fast charging performance of eutectic electrolytes. In addition, stable SEI layer enriched with inorganic components is formed during the cycling process, resulting in uniform and dense lithium deposition. The fast charging performance of the cell can be effectively improved by utilizing the interaction between anions and solvents. The LiFePO (LFP)||Li cell has a capacity retention of 97% after 1200 cycles at 5 C and also performs well at high temperature of 50 °C. Overall, the use of a non-solvating cosolvent in eutectic electrolytes presents a promising and innovative approach for enhancing electrolyte performance in LMBs.
合理设计溶剂化结构对于锂金属电池（LMBs）的发展至关重要。本文提出在酰胺基共晶电解质中使用1,2 - 二甲氧基乙烷（DME）作为非溶剂化共溶剂，以应对与高粘度、高极化和低电导率相关的挑战，从而增强与锂金属负极的兼容性。通过物理表征结合模拟计算，证实了DME与阴离子之间存在弱相互作用，这促进了锂盐的解离，增加了锂离子迁移数和扩散系数，从而提高了共晶电解质的快充性能。此外，在循环过程中形成了富含无机成分的稳定固体电解质界面（SEI）层，导致锂沉积均匀且致密。利用阴离子与溶剂之间的相互作用可以有效提高电池的快充性能。LiFePO（LFP）||Li电池在5C下1200次循环后容量保持率为97%，在50°C的高温下也表现良好。总体而言，在共晶电解质中使用非溶剂化共溶剂为提高LMBs中的电解质性能提供了一种有前景的创新方法。
