Liu Chengkun, Jiang Zhipeng, Zhang Yuhang, Xie Wenjun, Zou Jiahang, Wu Shilin, Sun Mengjun, Li Yongtao
School of Materials Science and Engineering, Anhui University of Technology Maanshan 243002 China
Key Laboratory of Efficient Conversion and Solid-state Storage of Hydrogen & Electricity of Anhui Province Maanshan 243002 China.
Chem Sci. 2025 Mar 25;16(18):7847-7857. doi: 10.1039/d4sc07393b. eCollection 2025 May 7.
The advancement of high-energy-density lithium metal batteries (LMBs) necessitates the development of novel electrolytes capable of withstanding high voltages. Ether-based electrolytes, while compatible with lithium metal anodes (LMAs), face limitations in high-voltage stability. Traditional design strategies with high concentration enhance the high-voltage stability of electrolytes by consuming free solvents to prevent their decomposition but face high-cost issues. Herein, we introduce a novel design approach for high-voltage ether electrolytes that leverages strong Coulomb interactions between lithium ions (Li) and anions to construct an anion-dominated solvation structure. This solvation structure not only enhances de-solvation kinetics but also forms stable anion-derived interfaces at both electrodes, thereby maintaining electrode stability and preventing free solvent decomposition. Li-LiNiCoMnO (NCM811) cells using a strong Coulomb force electrolyte (SCE) designed based on this principle demonstrate superior rate performance (20C/120.8 mA h g) and cycling stability (5C/1000 cycles). Notably, even at an ultra-low concentration of 0.1 M, Li-NCM811 cells utilizing the SCE exhibit good rate performance (5C/121.9 mA h g) and stable cycling over 200 cycles at a cutoff voltage of 4.4 V. This approach provides a high-performance and cost-effective electrolyte solution for practical high-voltage LMB applications.
高能量密度锂金属电池（LMBs）的发展需要开发能够承受高电压的新型电解质。醚基电解质虽然与锂金属负极（LMA）兼容，但在高电压稳定性方面存在局限性。传统的高浓度设计策略通过消耗游离溶剂来防止其分解，从而提高电解质的高电压稳定性，但面临高成本问题。在此，我们介绍了一种用于高电压醚基电解质的新颖设计方法，该方法利用锂离子（Li）与阴离子之间强烈的库仑相互作用来构建以阴离子为主导的溶剂化结构。这种溶剂化结构不仅增强了去溶剂化动力学，还在两个电极上形成了稳定的阴离子衍生界面，从而保持电极稳定性并防止游离溶剂分解。基于这一原理设计的使用强库仑力电解质（SCE）的锂-锂镍钴锰氧化物（NCM811）电池展现出卓越的倍率性能（20C/120.8 mA h g）和循环稳定性（5C/1000次循环）。值得注意的是，即使在超低浓度0.1 M的情况下，使用SCE的锂-NCM811电池在4.4 V的截止电压下仍表现出良好的倍率性能（5C/121.9 mA h g）和超过200次循环的稳定循环。这种方法为实际的高电压LMB应用提供了一种高性能且具有成本效益的电解质解决方案。
