Enhancing the Stability of Metallic Li Anodes for Aprotic Li-O2 Batteries with Dual-Anion Electrolytes

Despite the impressive specific capacity of Li-O-2 batteries, challenges persist, particularly with lithium metal anode (LMA). These include dendritic growth and unstable solid electrolyte interface (SEI) layers, which become more pronounced in an oxygen-rich environment, a typical operation scenario for Li-O-2 batteries. Herein, utilizing a hybrid dual anion electrolyte (DAE) strategy, which incorporates both inorganic LiNO3 and organic Li[(FSO2)(C2F5SO2)N] (LiFPFSI) salts, the dendritic growth is evidently inhibited by creating a "concrete-like" SEI structure. Simultaneously, it fosters the development of a fluorine-rich SEI layer. Consequently, a robust, compact, and stable barrier is formed, adeptly suppressing side reactions between LMA and the electrolyte, particularly those relevant to dissolved O-2. The practicality and efficiency of this DAE strategy are validated across a variety of battery types including Li/Li, Li/Cu, and notably Li-O-2 batteries, which showcased significantly improved reversibility and durability. These results underscore the important role of multifunctional salts in interphase engineering for LMA, which could lead to advancements in Li-O-2 batteries.