ScholarWorks@성균관대학교

초록

Lithium (Li) metal batteries hold great promise due to their high energy density, yet severe side reactions between routine organic electrolytes and the Li metal anode hinder their practical implementation. Elucidating the fundamental mechanisms that govern electrolyte stability on the Li metal anode is crucial to stabilizing the electrolyte–anode interface and promoting the practical applications of Li metal batteries. Herein, the regulation mechanism of the anode surface on the electrolyte stability is revealed at the atomic scale by density functional theory calculations. Indicated by the changes in the lowest unoccupied molecular orbital (LUMO) energy levels, solvents exhibit markedly lower reductive stability on Li metal surfaces compared with bulk molecules, making them more prone to parasitic reactions. Two major components in solid electrolyte interphase (SEI), i.e., LiF and Li2O, can passivate the solvent reduction through an average increase of 1.46 eV in their LUMO energy levels. The LUMO energy changes are further correlated with the Li–O distance between the solvents and SEI components, exhibiting an approximately linear relationship. This work reveals the role of the SEI in protecting Li metal anodes from electrolyte corrosion and identifies key factors regulating solvent stability, providing fundamental insights for the rational design of advanced electrolytes and robust SEI for practical Li metal batteries.

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