Nature Communications (Apr 2023)

Multifunctional solvent molecule design enables high-voltage Li-ion batteries

  • Junbo Zhang,
  • Haikuo Zhang,
  • Suting Weng,
  • Ruhong Li,
  • Di Lu,
  • Tao Deng,
  • Shuoqing Zhang,
  • Ling Lv,
  • Jiacheng Qi,
  • Xuezhang Xiao,
  • Liwu Fan,
  • Shujiang Geng,
  • Fuhui Wang,
  • Lixin Chen,
  • Malachi Noked,
  • Xuefeng Wang,
  • Xiulin Fan

DOI
https://doi.org/10.1038/s41467-023-37999-4
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 14

Abstract

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Abstract Elevating the charging cut-off voltage is one of the efficient approaches to boost the energy density of Li-ion batteries (LIBs). However, this method is limited by the occurrence of severe parasitic reactions at the electrolyte/electrode interfaces. Herein, to address this issue, we design a non-flammable fluorinated sulfonate electrolyte by multifunctional solvent molecule design, which enables the formation of an inorganic-rich cathode electrolyte interphase (CEI) on high-voltage cathodes and a hybrid organic/inorganic solid electrolyte interphase (SEI) on the graphite anode. The electrolyte, consisting of 1.9 M LiFSI in a 1:2 v/v mixture of 2,2,2-trifluoroethyl trifluoromethanesulfonate and 2,2,2-trifluoroethyl methanesulfonate, endows 4.55 V-charged graphite||LiCoO2 and 4.6 V-charged graphite||NCM811 batteries with capacity retentions of 89% over 5329 cycles and 85% over 2002 cycles, respectively, thus resulting in energy density increases of 33% and 16% compared to those charged to 4.3 V. This work demonstrates a practical strategy for upgrading the commercial LIBs.