Ultrafast Charging of a 4.8 V Manganese‐Rich Cathode‐Based Lithium Metal Cell by Constructing Robust Solid Electrolyte Interphases

Abstract Fast charging of Li‐metal battery (LMB) is a challenging issue owing to the interfacial instability of Li‐metal anode in liquid electrolyte and Li‐dendrites growth, resulting in fire hazard. Those issues motivated to pioneer a stabilization strategy of liquid electrolyte‐derived solid electrolyte interphase (SEI) layer that enables dendrites‐free Li‐metal anode under extremely high current density, which solid‐state battery cannot. Here, the novel electrolyte formulation is reported including trace‐level pentafluoropropionic anhydride (PFPA) combined with fluoroethylene carbonate (FEC) additives, and the SEI stabilization in Li//Mn‐rich LMB, achieving unprecedented ultrafast charging under simultaneous extreme conditions of 20 C (charged in 3 min), 4.8 V and 45 °C, delivering 118 mAh g −1 for long reversible 400 cycles, and unprecedented high stability of Li//Li cell under extremely high current 10 mA cm −2 (Li stripping/plating in 6 min) for a prolonged time of 200 h. The SEI analysis results reveal that the PFPA, which has a symmetric 10 F‐containing molecular structure, is a strong F source for promptly producing thin, uniform, and robust F‐ and organics‐enriched SEI layers at both Li‐metal anode and Mn‐rich cathode, preventing Li‐dendrites. This study provides a potential concept for ultrafast charging, long‐cycled, and safer high‐energy LMBs and LIBs.