复旦大学王飞团队开发出循环醚基深共晶弱溶剂化电解质，用于稳定高温锂金属电池。相关研究成果发表在2024年12月2日出版的《德国应用化学》。

深共晶电解质（DEE）已成为一种用于解决锂金属电池在高温下的不稳定性和安全性问题的创新方法。然而，在实践中，低共熔混合物和电极之间通常存在不理想的不相容性，并且由于Li⁺浓度的增加，DEE的还原稳定性不足。

该文中，研究人员利用弱溶剂化四氢吡喃（THP）溶剂设计了一种新的DEE。由于THP和浓缩双（三氟甲磺酰基）酰亚胺锂（LiTFSI）的高还原电阻，这种DEE与锂金属阳极的兼容性增强，与LiMn₂O₄阴极的耐高温性增强。Li||LiMn₂O₄电池（1.6 mAh cm^-2）在室温下600次循环后显示出96.02%的高容量保持率。

更重要的是，这种Li||LiMn₂O₄电池具有显著的高温性能，在120次循环后容量保持率高达91.72%，在55°C的高温下储存240小时后自放电低，这对LiMn₂O₄阴极至关重要。

总体而言，这种电解质设计为高温高压锂金属电池的DEE开发提供了一条替代途径，也可以扩展到其他电池。

附：英文原文

Title: Weakly Solvating Cyclic Ether-Based Deep Eutectic Electrolytes for Stable High-Temperature Lithium Metal Batteries

Author: Yanru Yang, Qin Li, Huan Li, Jiafeng Ruan, Fengmei Wang, Ziyue Li, Jinyu Yang, Jiayun Zhang, U, Dalin Sun, Fang Fang, Muharrem Kunduraci, Fei Wang

Issue&Volume: 2024-12-02

Abstract: Deep eutectic electrolytes (DEE) have emerged as an innovative approach to address the instability and safety issues of lithium metal batteries at elevated temperatures. However, in practice, there is often an undesirable incompatibility between the eutectic mixture and electrodes, and also an insufficient reduction stability of DEE due to the increased Li+ concentration. Herein, we designed a new DEE by utilizing weakly solvating tetrahydropyran (THP) solvent. Due to the high reduction resistance of THP and concentrated lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), this DEE demonstrates enhanced compatibility with Li metal anode and high temperature tolerance with LiMn2O4 cathode. The Li||LiMn2O4 cell (1.6 mAh cm2) shows a high capacity retention of 96.02% after 600 cycles at room temperature. More importantly, this Li||LiMn2O4 cell achieves a remarkable high-temperature performance with a high capacity retention of 91.72% after 120 cycles and low self-discharge after storage for 240 hours at a high temperature of 55 °C, which is critical for LiMn2O4 cathode. Overall, this electrolyte design provides an alternative pathway for the development of DEEs for high-temperature and high-voltage lithium metal batteries, which can also be expanded to other batteries.

DOI: 10.1002/anie.202419653

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202419653