Cai Yichao, Hou Yunpeng, Lu Yong, Zhang Qiu, Yan Zhenhua, Chen Jun
Renewable Energy Conversion and Storage Center (RECAST), Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin, 300071, China.
Angew Chem Int Ed Engl. 2023 Apr 17;62(17):e202218014. doi: 10.1002/anie.202218014. Epub 2023 Mar 14.
Li-O batteries with bis(trifluoromethanesulfonyl)imide-based ionic liquid (TFSI-IL) electrolyte are promising because TFSI-IL can stabilize O to lower charge overpotential. However, slow Li transport in TFSI-IL electrolyte causes inferior Li deposition. Here we optimize weak solvating molecule (anisole) to generate anisole-doped ionic aggregate in TFSI-IL electrolyte. Such unique solvation environment can realize not only high Li transport parameters but also anion-derived solid electrolyte interface (SEI). Thus, fast Li transport is achieved in electrolyte bulk and SEI simultaneously, leading to robust Li deposition with high rate capability (3 mA cm ) and long cycle life (2000 h at 0.2 mA cm ). Moreover, Li-O batteries show good cycling stability (a small overpotential increase of 0.16 V after 120 cycles) and high rate capability (1 A g ). This work provides an effective electrolyte design principle to realize stable Li deposition and high-performance Li-O batteries.
具有双（三氟甲磺酰）亚胺基离子液体（TFSI-IL）电解质的锂氧电池很有前景，因为TFSI-IL可以稳定O以降低充电过电位。然而，TFSI-IL电解质中Li传输缓慢会导致Li沉积不佳。在这里，我们优化了弱溶剂化分子（苯甲醚），以在TFSI-IL电解质中生成苯甲醚掺杂的离子聚集体。这种独特的溶剂化环境不仅可以实现高Li传输参数，还可以实现阴离子衍生的固体电解质界面（SEI）。因此，在电解质本体和SEI中同时实现了快速Li传输，从而实现了具有高倍率性能（3 mA cm）和长循环寿命（在0.2 mA cm下2000 h）的稳健Li沉积。此外，锂氧电池表现出良好的循环稳定性（120次循环后过电位仅小幅增加0.16 V）和高倍率性能（1 A g）。这项工作提供了一种有效的电解质设计原则，以实现稳定的Li沉积和高性能锂氧电池。
