Cation-Solvent, Cation-Anion, and Solvent-Solvent Interactions with Electrolyte Solvation in Lithium Batteries

Electrolyte solvation is a fundamental issue that regulates the lithium (Li) ion solvation sheath structure, the formation of cathode/anode-electrolyte interphase, and the plating/stripping behavior of Li ions in working Li batteries. Herein, we probe the cation-solvent, cation-anion, and solvent-solvent interactions under both vacuum and electrolyte conditions through density functional theory calculations. The solvation effects can significantly weaken the aforementioned interactions in electrolytes as well as increase the Li-O/F distances in Li+-containing complexes. The dissolution behaviour of Li salts in electrolytes was further explored and experimentally validated by dissolving lithium nitrate in different solvents. This work affords a mechanistic understanding of electrolyte microstructure and highlights the significant role of electrolyte solvation in regulating battery performance, affording fruitful insights into emerging electrolyte design for high-performance batteries.