Recent progress in electrolyte design for advanced lithium metal batteries

Abstract Lithium metal batteries (LMBs) have attracted considerable interest for use in electric vehicles and as next‐generation energy storage devices because of their high energy density. However, a significant practical drawback with LMBs is the instability of the Li metal/electrolyte interface, with concurrent parasitic reactions and dendrite growth, that leads to low Coulombic efficiency and poor cycle life. Owing to the significant role of electrolytes in batteries, rationally designed electrolytes can improve the electrochemical performance of LMBs and possibly achieve fast charge and a wide range of working temperatures to meet various requirements of the market in the future. Although there are some review papers about electrolytes for LMBs, the focus has been on a single parameter or single performance separately and, therefore, not sufficient for the design of electrolytes for advanced LMBs for a wide range of working environments. This review presents a systematic summary of recent progress made in terms of electrolytes, covering the fundamental understanding of the mechanism, scientific challenges, and strategies to address drawbacks of electrolytes for high‐performance LMBs. The advantages and disadvantages of various electrolyte strategies are also analyzed, yielding suggestions for optimum properties of electrolytes for advanced LMBs applications. Finally, the most promising research directions for electrolytes are discussed briefly.