Antisolvent‐Regulated Anionic Coordination Enabling Stable Li Metal Anode in Urea‐Based Electrolyte

Abstract The fabrication of NO 3 − anion‐participating solvation sheaths to derive inorganic‐rich solid electrolyte interphase (SEI) layers is critical for enhancing the stabilization of lithium metal batteries (LMBs). However, the application of LiNO 3 salt is limited by its low solubility and the challenge of controlling NO 3 − coordination, primarily due to its high donor number. Herein, we demonstrate an antisolvent‐enhanced anionic coordination effect in urea‐based LiNO 3 electrolytes for boosting the cycling stability of LMBs. We find that the incorporation of 1,1,2,2‐tetrafluoroethyl‐2,2,3,3‐tetrafluoropropyl ether (TTE) into these electrolytes enhances the interaction between the NO 3 − anion and urea‐based solvent to Li + in the solvation sheath, resulting in an increase in ion‐pair formation. This also induces a transformation of the NO 3 − anion from a monodentate to a bidentate coordination configuration, facilitating preferential nitrate reduction at the anode interface. The optimized electrolyte formulation demonstrates remarkable cycling stability in lithium metal anode, achieving 6000 h of operation in a Li||Li cell and a high Coulombic efficiency of 99.6% in a Li||Cu cell. In full‐cell testing, Li||LiFePO 4 cells (N/P = 3) maintain 88% capacity retention after 100 cycles at 0.2C.