Recent progress in constructing halogenated interfaces for highly stable lithium metal anodes

Lithium metal batteries (LMBs) are considered one of the most promising next-generation energy storage devices due to their great potential for enhancing energy density. However, the uncontrolled lithium (Li) dendrite growth and the inevitable formation of a native solid electrolyte interface (SEI) severely deteriorate the electrochemical performances and exacerbate the safety risks of LMBs, dragging LMBs out of practical applications. Improving the interface properties of Li metal anodes (LMAs) through the construction of halogenated interfaces is expected to overcome the above-described challenges because of the prominent advantages of halogenated interfaces in passivating active Li surfaces, regulating the diffusion and migration of Li ions, and improving interface mechanical stability. In this review, the effects of various halogenated interfaces on the stability and electrochemical properties of LMAs are discussed in detail. The emerging strategies for constructing advanced halogenated interfaces and their protection mechanisms are comprehensively summarized. Moreover, the representative advanced characterization techniques for the anode/electrolyte interfaces are also reviewed. The remaining challenges and potential opportunities for the future development and rational design of halogenated interfaces are highlighted, with the aim of indicating future research directions related to the significant strategy of constructing halogenated interfaces to achieve highly stable LMBs.