Recent progress in constructing fluorinated solid electrolyte interphase for stable lithium metal anodes

Lithium metal batteries (LMBs) are promising high-energy-density battery systems due to their high specific capacity. However, the non-uniform plating of lithium (Li) and the collapse of the solid electrolyte interphase (SEI) during cycling gives rise to the risk of dendrite growth, which could penetrate the separator and bring the hazards of short-circuit. The availability of stable SEI is a prerequisite for the long-term operation of the batteries to overcome these challenges. Fluorinate-rich SEI has attracted much attention due to its effective passivation of electrodes, regulation of Li deposition and inhibition of electrolyte corrosion. This paper reviews the research on optimizing the preparation of LiF passivation interfaces for the protection of lithium metal anodes, and four types of compositions introduced in fluorinated SEI to synergistically enhance the comprehensive performance of SEI. By emphasizing the importance of interphasial structures, this review offers comprehensive guidance for the design and development of LMBs.