Revealing the Multifunctions of LiN in the Suspension Electrolyte for Lithium Metal Batteries.

Inorganic-rich solid-electrolyte interphases (SEIs) on Li metal anodes improve the electrochemical performance of Li metal batteries (LMBs). Therefore, a fundamental understanding of the roles played by essential inorganic compounds in SEIs is critical to realizing and developing high-performance LMBs. Among the prevalent SEI inorganic compounds observed for Li metal anodes, LiN is often found in the SEIs of high-performance LMBs. Herein, we elucidate new features of LiN by utilizing a suspension electrolyte design that contributes to the improved electrochemical performance of the Li metal anode. Through empirical and computational studies, we show that LiN guides Li electrodeposition along its surface, creates a weakly solvating environment by decreasing Li-solvent coordination, induces organic-poor SEI on the Li metal anode, and facilitates Li transport in the electrolyte. Importantly, recognizing specific roles of SEI inorganics for Li metal anodes can serve as one of the rational guidelines to design and optimize SEIs through electrolyte engineering for LMBs.