Dipole Moment Influences the Reversibility and Corrosion of Lithium Metal Anodes.

Lithium metal batteries (LMBs) must have both long cycle life and calendar life to be commercially viable. However, "trial and error" methodologies remains prevalent in contemporary research endeavors to identify favorable electrolytes. Here, we propose a guiding principle for the selection of solvents for LMBs, which aims to achieve high coulombic efficiency while minimizing the corrosion. For the first time, our study reveals the dipole moment and orientation of solvent molecules have significant impacts on lithium metal reversibility and corrosion. Solvents with high dipole moments are more likely to adsorb onto lithium metal surfaces, which also influences the solid electrolyte interphase. Using this principle, we demonstrate the use of LiNO 3 as the sole salt in NCM811/Li cells can achieve excellent cycling stability. Overall, our work bridges the molecular structure of solvents to the reversibility and corrosion of lithium metal, and these concepts can be extended to other metal-based batteries. This article is protected by copyright. All rights reserved.