Yang Yanru, Li Qin, Li Huan, Ruan Jiafeng, Wang Fengmei, Li Ziyue, Yang Jinyu, Zhang Jiayun, Çağlayan Uğur, Sun Dalin, Fang Fang, Kunduraci Muharrem, Wang Fei
Department of Materials Science, Fudan University, Shanghai, 200433, China.
Central Research Laboratory, Çukurova University, Adana, Türkiye.
Angew Chem Int Ed Engl. 2025 Feb 10;64(7):e202419653. doi: 10.1002/anie.202419653. Epub 2024 Dec 8.
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 LiMnO cathode. The Li||LiMnO cell (1.6 mAh cm) shows a high capacity retention of 96.02 % after 600 cycles at room temperature. More importantly, this Li||LiMnO 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 LiMnO 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.
深共熔电解质（DEE）已成为解决锂金属电池在高温下的不稳定性和安全问题的一种创新方法。然而，在实际应用中，共熔混合物与电极之间往往存在不良的不相容性，而且由于锂浓度的增加，DEE的还原稳定性不足。在此，我们通过使用弱溶剂化四氢吡喃（THP）溶剂设计了一种新型DEE。由于THP和高浓度双（三氟甲磺酰）亚胺锂（LiTFSI）具有高还原抗性，这种DEE与锂金属阳极表现出增强的相容性，与LiMnO阴极具有高温耐受性。Li||LiMnO电池（1.6 mAh cm）在室温下经过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||LiMnO电池具有卓越的高温性能，在55 °C高温下储存240小时后自放电率低，在120次循环后具有91.72 %的高容量保持率，这对LiMnO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，也可扩展到其他电池。
