Achieving ultralong cycle life graphite binary intercalation in intermediate-concentration ether-based electrolyte for potassium-ion batteries

Yu Lei, Jiali Wang, Da Han, Fu Yuan, Huwei Wang, Rongyi Zhao, Daqing Huang, Yiying Wu, Biao Zhang, Dengyun Zhai, Feiyu Kang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

Controlling graphite intercalation is vital for its use in potassium ion batteries. Prior studies have revealed different intercalation behaviors between a dilute (1 M or less) vs. a concentrated (4 M or higher) ether-based electrolytes: the former forms solvent-co-intercalation while the latter shows binary intercalation. However, no study has been carried out on the intermediate concentrations. In this work, for the first time we report that in an intermediate concentration of electrolyte (2 mol KFSI per kg DME, 2 mol/kg) the electrochemical intercalation of K+ ions in graphite anode exhibits an interesting transition from the ternary to binary process with the increasing cycle number. Furthermore, the pre-formed anion-derived solid-electrolyte interphase on graphite anode in highly concentrated electrolyte was rather stable in 2 mol/kg of KFSI/DME electrolyte, and as a result the graphite anode achieved a two-year cycle life with an ultrahigh capacity retention of 96.7% based on binary intercalation.

Original languageEnglish
Pages (from-to)229-235
Number of pages7
JournalCarbon
Volume196
DOIs
Publication statusPublished - 30 Aug 2022

Keywords

  • Graphite anode
  • Intercalation
  • Potassium-ion battery
  • Solid-electrolyte interphase

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)

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