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

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 degrees C-60 degrees C) and superior power capability (fast charge rates up to 5.0 C) for the graphite||LiNi0.8Co0.1Mn0.1O2 (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.

Automated summary

Electrolyte design is crucial for improving the performance of lithium-ion batteries. However, conventional electrolytes pose safety risks due to their flammability and reactivity at high voltage and extreme temperatures. In this study, a non-flammable fluorinated ester electrolyte was designed, which demonstrated high cycling stability and superior power capability for a graphite||LiNi0.8Co0.1Mn0.1O2 (NCM811) battery operated at high voltage (>4.3 V vs. Li/Li+) and wide temperature variations (-50 degrees C-60 degrees C). Furthermore, the research provided new insights into the molecular-level dynamics and interactions among Li+, solvent, and anion, and facilitated the development of high-safety and high-energy-density batteries for harsh conditions.