Designing Nonflammable Liquid Electrolytes for Safe Li-Ion Batteries

Li-ion batteries are essential technologies for electronic products in the daily life. However, serious fire safety concerns that are closely associated with the flammable liquid electrolyte remains a key challenge. Tremendous effort has been devoted to designing nonflammable liquid electrolytes. It is critical to gain comprehensive insights into nonflammability design and inspire more efficient approaches for building safer Li-ion batteries. This review presents current mechanistic understanding of safety issues and discusses state-of-the-art nonflammable liquid electrolytes design for Li-ion batteries based on molecule, solvation, and battery compatibility level. Various safety test methods are discussed for reliable safety risk evaluation. Finally, the challenges and perspectives of the nonflammability design for Li-ion electrolytes are summarized.