Citation

Chung GJ, Han J, Song SW. ACS Appl. Mater. Interfaces 2020; ePub(ePub): ePub.

Copyright

(Copyright © 2020, American Chemical Society)

DOI

10.1021/acsami.0c12702

PMID

32897056

Abstract

Battery safety is an ever-increasing significance to guarantee consumer's safety. Reducing or preventing the risk of battery fire and explosion is a must for battery manufacturers. Major reason for the occurrence of fire in commercial lithium-ion batteries is the flammability of conventional organic liquid electrolyte, which is typically composed of 1 M LiPF6 salt and ethylene carbonate (EC)-based organic solvents. Herein, we report the designed 1 M LiPF6 and EC-based nonflammable electrolyte including methyl(2,2,2-trifluoroethyl)carbonate, which breaks the conventional perception that EC-based liquid electrolyte is always flammable. The designed electrolyte also provides high anodic stability beyond the conventional charge cut-off voltage of 4.2 V. A graphite∥LiNi0.6Co0.2Mn0.2O2 lithium-ion full cell with our designed EC-based nonflammable electrolyte with a small fraction of vinylene carbonate additive under an aggressive condition of 4.5 V charge cut-off voltage, 0.5C rate, and 45 °C exhibits increased capacity, reduced interfacial resistance, and improved performance and rate capability. A basic understanding of how a high-voltage cathode-electrolyte interface and anode-electrolyte interface are stabilized and how failure modes are mitigated by fire-preventing electrolyte is discussed.

Language: en

Keywords

safety; fire-preventing organic liquid electrolyte; high voltage; Li-ion batteries; solid electrolyte interphase (SEI)