Ionic liquid enabled FeS2 for high-energy-density lithium-ion batteries

Adv Mater. 2014 Nov 19;26(43):7386-92. doi: 10.1002/adma.201402103. Epub 2014 Sep 18.

Abstract

High-energy-density FeS2 cathodes en-abled by a bis(trifluoromethanesulfonyl)imide (TFSI-) anion-based room temperature ionic liquid (RTIL) electrolyte are demonstrated. A TFSI-based ionic liquid (IL) significantly mitigates polysulfide dissolution, and therefore the parasitic redox shuttle mechanism, that plagues sulfur-based electrode chemistries. FeS2 stabilization with a TFSI(-) -based IL results in one of the highest energy density cathodes, 542 W h kg(-1) (normalized to cathode composite mass), reported to date.

Keywords: bis(trifluoromethanesulfonyl)imide; cathodes; polysulfide dissolution; pyrite; room temperature ionic liquids.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dielectric Spectroscopy
  • Electric Power Supplies*
  • Electrodes
  • Fourier Analysis
  • Hydrocarbons, Fluorinated / chemistry*
  • Imides / chemistry*
  • Ionic Liquids / chemistry*
  • Ions / chemistry*
  • Iron / chemistry*
  • Lithium / chemistry*
  • Microscopy, Electron, Transmission
  • Spectrum Analysis
  • Sulfides / chemistry*

Substances

  • Hydrocarbons, Fluorinated
  • Imides
  • Ionic Liquids
  • Ions
  • Sulfides
  • bis(trifluoromethanesulfonyl)imide
  • pyrite
  • Lithium
  • Iron