Intrinsic Structural and Coordination Chemistry Insights of Li Salts in Rechargeable Lithium Batteries

Lithium batteries, favored for their high energy density and long lifespan, are staples in electric vehicles, portable electronics, and aerospace. A key component, Li salts, aids lithium ion migration and electrode protection, significantly impacting battery performance. Developing an ideal Li salt, balancing stability, solubility, dissociation, solvation, and eco-friendliness, remains challenging. Given the scarcity of relevant reviews, it is endeavored here to present a novel perspective on Li salt chemistry, offering a concise roadmap for future designs and innovations. It is delved into the trends, opportunities, design principles, and evaluation methodologies related to Li salt chemistry, with a particular emphasis on organic anionic compositions. Furthermore, the latest and most representative organic Li salts from their intrinsic structure and coordination chemistry, highlighting their unique features and contributions are organized and presented. Finally, a visionary outlook is articulated for this field, exploring avenues, such as customizing Li salts for specific applications, synthesizing Li salts on demand, and discussing the potential of F-free Li salts alongside with their electrochemical window challenges. Here it is served as a strategic compass, addressing the shortcomings of existing reviews and guiding the design of functionalized Li salts.