Fluorination-mediated solvation remodeling of ethylene carbonate-free carbonate electrolytes affords stable 4.6...

High-voltage lithium metal batteries (LMBs) represent the most promising route to next-generation high-energy-density energy storage, yet their practical deployment is severely bottlenecked by conventional ethylene carbonate (EC)-based electrolytes, which suffer from a narrow electrochemical window below 4.3 V, unstable electrode-electrolyte interphases, uncontrolled Li dendrite growth, and a high Li⁺ desolvation barrier from strong EC-Li⁺ chelation. Herein, we propose an EC-free fluorination strategy to construct a series of carbonate electrolytes, with the optimized fully fluorinated solvent formulation of 3,3,3-trifluoropropylene carbonate (TFPC) and fluoroethyl methyl carbonate (FEMC) to precisely tailor the Li⁺ solvation into an F-solvent/anion-enriched structure. This design enables the formation of the robust LiF-rich dual interphases on both the Li anode and 4.6 V LiNi_0.9Co_0.05Mn_0.05O₂ (NCM90) cathode, delivering a 95% average coulombic efficiency over 150 cycles in Li‖Cu cells, and 82.3% (25 °C) and 82.6% (50 °C) capacity retention after 100 cycles at 1C in LMBs, along with outstanding rate and wide-temperature-tolerance properties. More essentially, this contribution offers a rational design paradigm in electrolyte chemistry for high-performance EC-free electrolytes toward next-generation high-energy-density LMBs.