Tu Haifeng, Wang Zhicheng, Xue Jiangyan, Tang Zhiyong, Liu Yang, Liu Xiaofang, Liu Lingwang, Lu Suwan, Weng Shixiao, Gao Yiwen, Sun Guochao, Liu Zheng, Peng Keyang, Zhang Xin, Li Dejun, Wu Guangye, Liu Meinan, Hu Jianchen, Li Hong, Xu Jingjing, Wu Xiaodong
School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei, Anhui, 230026, China.
i-lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China.
Angew Chem Int Ed Engl. 2025 Jan 2;64(1):e202412896. doi: 10.1002/anie.202412896. Epub 2024 Nov 7.
The development of high-voltage lithium metal batteries (LMBs) encounters significant challenges due to aggressive electrode chemistry. Recently, locally concentrated ionic liquid electrolytes (LCILEs) have garnered attention for their exceptional stability with both Li anodes and high-voltage cathodes. However, there remains a limited understanding of how diluents in LCILEs affect the thermodynamic stability of the solvation structure and transportation dynamics of Li ions. Herein, we propose a wide-temperature LCILEs with 1,3-dichloropropane (DCP13) diluent to construct a non-equilibrium solvation structure under external electric field, wherein the DCP13 diluent enters the Li ion solvation sheath to enhance Li ion transport and suppress oxidative side reactions at high-nickel cathode (LiNiCoMnO, NCM90). Consequently, a Li/NCM90 cell utilizing this LCILE achieves a high capacity retention of 94 % after 240 cycles at 4.3 V, also operates stably at high cut-off voltages from 4.4 V to 4.6 V and over a wide temperature range from -20 °C to 60 °C. Additionally, an Ah-level pouch cell with this LCILE simultaneously achieves high-energy-density and stable cycling, manifesting the practical feasibility. This work redefines the role of diluents in LCILEs, providing inspiration for electrolyte design in developing high-energy-density batteries.
由于电极化学性质活泼，高压锂金属电池（LMBs）的发展面临重大挑战。最近，局部浓集离子液体电解质（LCILEs）因其对锂阳极和高压阴极都具有出色的稳定性而受到关注。然而，对于LCILEs中的稀释剂如何影响溶剂化结构的热力学稳定性和锂离子的传输动力学，人们的了解仍然有限。在此，我们提出一种含有1,3-二氯丙烷（DCP13）稀释剂的宽温度LCILEs，以在外部电场下构建非平衡溶剂化结构，其中DCP13稀释剂进入锂离子溶剂化鞘层，以增强锂离子传输并抑制高镍阴极（LiNiCoMnO，NCM90）处的氧化副反应。因此，使用这种LCILE的Li/NCM90电池在4.3 V下循环240次后实现了94%的高容量保持率，在4.4 V至4.6 V的高截止电压以及-20°C至60°C的宽温度范围内也能稳定运行。此外，采用这种LCILE的Ah级软包电池同时实现了高能量密度和稳定循环，证明了其实际可行性。这项工作重新定义了稀释剂在LCILEs中的作用，为开发高能量密度电池的电解质设计提供了灵感。
