Nitrile-Assisted Hybrid-Solvation Electrolyte Enables Wide-Temperature, High-Voltage, and Ultrafast-Charging...

The stable operation of lithium metal batteries (LMBs) requires simultaneous stabilization of anode and cathode interfaces, a challenge that intensifies under extreme operating conditions due to divergent formation mechanisms. Here, we present a hybrid-solvation electrolyte design employing isobutyronitrile (IBN) as the primary solvent to regulate both Li⁺ solvation and interfacial protection. Functioning as a bifunctional modulator, IBN drives dual-source interfacial chemistry at the anode where anion-enriched solvation and coordinated-solvent decomposition co-generate an inorganic- and nitrogen-rich solid-electrolyte interphase (SEI) while lowering Li⁺ desolvation barriers. At the cathode surface, excess IBN molecules form an adsorption-derived protective layer that effectively suppresses solvent oxidation and stabilizes the cathode-electrolyte interface (CEI) under high-voltage and high-temperature conditions. Enabled by this design, Li||LiNi_0.8Co_0.1Mn_0.1O₂ coin cells exhibit robust operation across wide temperatures (-40°C∼60°C) and high voltages (4.6 V), alongside ultrafast charging capabilities (20 C). Upscaling to practical pouch cells under lean-electrolyte conditions (1.2 g Ah^-1) yields a high energy density of 403 Wh kg^-1 with a 12-min fast-charging/discharging capability. The hybrid solvation design framework integrates solvent- and anion-driven chemistries in a unified electrolyte, enabling high-energy LMB operation under demanding conditions.