Lithium metal batteries (LMBs) have attracted more attention for their high energy densities. Their applications are limited for the poor low temperature (LT) cycle performance and the growth of dendrite due to the root problems of high Li⁺ desolvation energy barrier and poor electrode/electrolyte interface. Here, an electrolyte was prepared using low dielectric constant solvents of ethyl acetate (EA), 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether (D2), and the high voltage endurance lithium salt lithium difluoro(oxalato)borate (LiDFOB), which exhibits high ionic conductivity of 1 mS/cm even at −50 °C and superior high voltage tolerance. Moreover, fluoroethylene carbonate (FEC) is further introduced to realize the temperature-responsive solvation structure, which induces an enriched inorganic solid electrolyte interphase (SEI) film and homogeneous lithium deposition. Therefore, Li∥NCM87 batteries not only deliver outstanding ambient temperature performance (89% capacity retention after 290 cycles) but also can operate at LT of −40 °C for 40 cycles with a stable capacity of 120 mA h/g. This work can enlighten the development and design of an electrolyte operating under extreme conditions.

中文翻译：

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使用可控溶剂化结构电解质提高锂电池的低温性能


锂金属电池 （LMB） 因其高能量密度而引起了更多关注。由于高 Li⁺ 脱溶剂能垒和电极/电解质界面不良的根本问题，它们的低温 （LT） 循环性能差和枝晶生长，其应用受到限制。在这里，使用乙酸乙酯 （EA）、1,1,2,2-四氟乙基-2,2,3,3-四氟丙基醚 （D2） 的低介电常数溶剂和耐高压锂盐二氟（草酸）硼酸锂 （LiDFOB） 制备电解质，即使在 -50 °C 下也表现出 1 mS/cm 的高离子电导率和卓越的耐高压性。此外，进一步引入氟碳酸乙烯酯 （FEC） 以实现温度响应溶剂化结构，诱导富集的无机固体电解质界面 （SEI） 膜和均匀的锂沉积。因此，Li∥NCM87 电池不仅提供出色的环境温度性能（290 次循环后仍能保持 89% 的容量），而且可以在 -40 °C 的 LT 下运行 40 次循环，容量稳定为 120 mA h/g。这项工作可以启发在极端条件下运行的电解质的开发和设计。