Ternary‐Anions‐Driven Minimized Solvent Coordination for Extreme Condition‐Adaptive Weakly Solvating Lithium‐Ion Batteries Electrolytes

ABSTRACT Driven by expanding applications of lithium‐ion batteries, demand grows for enhanced performance under extreme conditions such as fast charging, low temperature, and high voltage. Low‐cost weak solvents show great potential for advanced electrolytes suited for fast‐charging and low‐temperature applications, but their poor electrochemical stability limits use with high‐voltage cathodes. Designing electrolytes that balance interfacial stability, ion transport kinetics, low‐temperature adaptation, and cost remains challenging. Here, we propose a ternary‐anion‐driven (PF 6 − , TFSI − , DFOB − ) minimized‐solvent‐coordination strategy using representative weak solvent tetrahydrofuran (THF) as the main component. This enables a stable ternary‐anion‐dominated solvation structure at a conventional 1.2 m concentration. Consequently, the designed electrolyte achieves reliable operation up to 4.3–4.4 V in NCM811//Gr full cells, even with oxidation‐sensitive THF comprising 97% of the solvent. This electrolyte simultaneously delivers exceptional fast‐charging performance (76.8% capacity retention at 6 C over 2000 cycles) and outstanding low‐temperature capability (95.1% retention after 100 cycles at −40°C) in NCM811//Gr cells. Moreover, it also enables stable cycling for 500 cycles in practical NCM811//Gr pouch cells and shows highly competitive performance in NCM811//Si/C cells.