Non‐Flammable Electrolyte Enables High‐Voltage and Wide‐Temperature Lithium‐Ion Batteries with Fast Charging

Abstract Electrolyte design has become ever more important to enhance the performance of lithium‐ion batteries (LIBs). However, the flammability issue and high reactivity of the conventional electrolytes remain a major problem, especially when the LIBs are operated at high voltage and extreme temperatures. Herein, we design a novel non‐flammable fluorinated ester electrolyte that enables high cycling stability in wide‐temperature variations (e.g., −50 °C–60 °C) and superior power capability (fast charge rates up to 5.0 C) for the graphite||LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) battery at high voltage (i.e., >4.3 V vs. Li/Li + ). Moreover, this work sheds new light on the dynamic evolution and interaction among the Li + , solvent, and anion at the molecular level. By elucidating the fundamental relationship between the Li + solvation structure and electrochemical performance, we can facilitate the development of high‐safety and high‐energy‐density batteries operating in harsh conditions.