Jiang Li-Li, Yan Chong, Yao Yu-Xing, Cai Wenlong, Huang Jia-Qi, Zhang Qiang
Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, P. R. China.
Key Laboratory for Special Functional Materials in, Jilin Provincial Universities, Jilin Institute of Chemical Technology, Jilin, 132022, P. R. China.
Angew Chem Int Ed Engl. 2021 Feb 15;60(7):3402-3406. doi: 10.1002/anie.202009738. Epub 2020 Dec 15.
Lithium-ion batteries with routine carbonate electrolytes cannot exhibit satisfactory fast-charging performance and lithium plating is widely observed at low temperatures. Herein we demonstrate that a localized high-concentration electrolyte consisting of 1.5 M lithium bis(fluorosulfonyl)imide in dimethoxyethane with bis(2,2,2-trifluoroethyl) ether as the diluent, enables fast-charging of working batteries. A uniform and robust solid electrolyte interphase (SEI) can be achieved on graphite surface through the preferential decomposition of anions. The established SEI can significantly inhibit ether solvent co-intercalation into graphite and achieve highly reversible Li intercalation/de-intercalation. The graphite | Li cells exhibit fast-charging potential (340 mAh g at 0.2 C and 220 mAh g at 4 C), excellent cycling stability (ca. 85.5 % initial capacity retention for 200 cycles at 4 C), and impressive low-temperature performance.
采用常规碳酸酯电解质的锂离子电池无法展现出令人满意的快速充电性能，并且在低温下普遍会出现锂金属沉积现象。在此，我们证明了一种局部高浓度电解质，其由1.5 M双（氟磺酰）亚胺锂在二甲氧基乙烷中，并以双（2,2,2-三氟乙基）醚作为稀释剂组成，能够实现工作电池的快速充电。通过阴离子的优先分解，可以在石墨表面形成均匀且坚固的固体电解质界面（SEI）。所形成的SEI能够显著抑制醚类溶剂共嵌入石墨，并实现高度可逆的锂嵌入/脱嵌。石墨|锂电池展现出快速充电能力（在0.2 C时为340 mAh g，在4 C时为220 mAh g）、出色的循环稳定性（在4 C下200次循环时初始容量保持率约为85.5 %）以及令人印象深刻的低温性能。
