Unique Non‐Chelating Multidentate Ligand Tuning Solvation Structure and Interfacial Chemistry for High‐Voltage Lithium Metal Batteries

Abstract Electrolyte engineering is a key strategy for achieving high‐energy lithium metal batteries. Among various solvents, fluorinated ether‐based electrolytes have shown promising results. However, these solvents often have several limitations: weak solvating ability, electrochemical reduction instability, and potential environmental hazards. Herein, a novel cyanated hexacyclic ether electrolyte (CHEE) is reported. The terminal cyano group (─CN) of solvent facilitates efficient Li + transport through its coordination ability, while the electron‐withdrawing nature of ─CN weakens the solvating ability of the ether oxygen atom. This modification leads to anion‐dominated solvation structures, wherein the nitrogen atom serves as the primary coordination site in the coordinated solvent. This unique non‐chelating, multidentate ligand enables a robust solid‐electrolyte interphase (SEI) and excellent electrochemical performance of lithium metal batteries. CHEE enables a Li–Cu cell to achieve a high coulombic efficiency of 99.5%, while a Li‐NMC811 cell demonstrates a capacity retention of 91% after 300 cycles. Notably, the Li‐NMC811 cell maintains stable cycling for 200 cycles at an elevated temperature of 60 °C. Furthermore, CHEE enables the operation of a Li‐NMC811 pouch cell with a low N/P, achieves a high capacity of 1.25 Ah. This study highlights the potential of cyanated ether in developing novel electrolyte systems for high‐performance lithium metal batteries.