Abstract: | In this study, self‐synthesized lithium trifluoro(perfluoro‐tert‐butyloxyl)borate (LiTFPFB) is combined with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) to formulate a novel 1 m dual‐salt electrolyte, which contains lithium difluorophosphate (LiPO2F2) additive and dominant carbonate solvents with low melting point and high boiling point. The addition of LiPO2F2 into this novel dual‐salt electrolyte dramatically improves cycleability and rate capability of a LiNi0.5Mn0.3Co0.2O2/Li (NMC/Li) battery, ranging from ?40 to 90 °C. The NMC/Li batteries adopt a Li–metal anode with low thickness of 100 µm (even 50 µm) and a moderately high cathode mass loading level of 10 mg cm?2. For the first time, this paper provides valuable perspectives for developing practical lithium–metal batteries over a wide temperature range. |