Stabilizing Carbonate Electrolytes by Partially Fluorinated Anion Additives for High‐Performance Lithium Metal Batteries

Conventional carbonate‐based electrolytes take merits of cost‐efficiency, high‐voltage stability, and Al current collector passivation, while their application in lithium metal batteries (LMBs) is severely hindered by issues such as lithium (Li) dendrite growth and unstable interfaces. Herein, we report that lithium difluoroacetate (LiDFA) with a partially fluorinated structure and strongly bonded Li + can act as a multifunctional electrolyte additive to stabilize LMBs in carbonate‐based electrolytes. The Lewis base property of DFA − can effectively suppress the hydrolysis of LiPF 6 , thereby improving the storage stability of the electrolyte. In addition, LiDFA can enhance the solubility of LiNO 3 in carbonate electrolytes, and the synergistic effect of the LiDFA and LiNO 3 contributes to the formation of an inorganic‐rich solid electrolyte interphase, facilitates dense and uniform Li deposition morphology, as well as accelerates the interfacial kinetics. Consequently, the designed additive‐modified electrolyte improves the reversibility of Li plating/stripping with a high Coulombic efficiency of 99.14% and enables long‐term cycling of Li||LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) over 150 cycles with a capacity retention of 82.72% under the condition of lean electrolyte, limited Li source, and conventional Li‐salt concentration. This work provides an effective and low‐cost strategy for designing high‐performance electrolytes for advanced battery systems.