Nano-Micro Letters (Jan 2022)

Safe and Stable Lithium Metal Batteries Enabled by an Amide-Based Electrolyte

  • Wanbao Wu,
  • Yiyang Bo,
  • Deping Li,
  • Yihong Liang,
  • Jichuan Zhang,
  • Miaomiao Cao,
  • Ruitian Guo,
  • Zhenye Zhu,
  • Lijie Ci,
  • Mingyu Li,
  • Jiaheng Zhang

DOI
https://doi.org/10.1007/s40820-021-00780-7
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 14

Abstract

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Highlights A novel amide-based nonflammable electrolyte is proposed. The formation mechanism and solvation chemistry are investigated by molecular dynamics simulations and density functional theory. An inorganic/organic-rich solid electrolyte interphase with an abundance of LiF, Li3N and Li–N–C is in situ formed, leading to spherical lithium deposition. The amide-based electrolyte can enable stable cycling performance at room temperature and 60 ℃. Abstract The formation of lithium dendrites and the safety hazards arising from flammable liquid electrolytes have seriously hindered the development of high-energy-density lithium metal batteries. Herein, an emerging amide-based electrolyte is proposed, containing LiTFSI and butyrolactam in different molar ratios. 1,1,2,2-Tetrafluoroethyl-2,2,3,3-tetrafluoropropylether and fluoroethylene carbonate are introduced into the amide-based electrolyte as counter solvent and additives. The well-designed amide-based electrolyte possesses nonflammability, high ionic conductivity, high thermal stability and electrochemical stability (> 4.7 V). Besides, an inorganic/organic-rich solid electrolyte interphase with an abundance of LiF, Li3N and Li–N–C is in situ formed, leading to spherical lithium deposition. The formation mechanism and solvation chemistry of amide-based electrolyte are further investigated by molecular dynamics simulations and density functional theory. When applied in Li metal batteries with LiFePO4 and LiMn2O4 cathode, the amide-based electrolyte can enable stable cycling performance at room temperature and 60 ℃. This study provides a new insight into the development of amide-based electrolytes for lithium metal batteries.

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