Fluorinated Solid-Electrolyte Interphase in High-Voltage Lithium Metal Batteries

Secondary batteries have shaped our modern life significantly, and high-energy-density rechargeable batteries are strongly required nowadays. However, practical Li-metal batteries have been hindered by short lifespan and safety concerns induced by Li dendrites during repeated cycles. The formation and growth of Li dendrites are mainly caused by unstable solid-electrolyte interphase (SEI) on Li-metal anode. Therefore, stable SEI on Li-metal anode is highly anticipated to promote practical applications of Li-metal batteries. The fluorinated SEI emerges as a promising SEI to regulate the behaviors of Li deposition and then enhance the stability and safety of Li-metal batteries. In this perspective, we concisely review the current fundamental understanding and key progresses of fluorinated SEI in high-voltage Li-metal batteries. Finally, we suggest the challenges and possible research directions for further development of fluorinated SEI in practical Li-metal batteries.