Suppressed lithium dendrite growth in lithium batteries using ionic liquid electrolytes: Investigation by electrochemical impedance spectroscopy, scanning electron microscopy, and in situ7Li nuclear magnetic resonance spectroscopy

Nina Schweikert, Andreas Hofmann, Michael Schulz, Marco Scheuermann, Steven Tyler Boles, Thomas Hanemann, Horst Hahn, Sylvio Indris

Research output: Journal article publicationJournal articleAcademic researchpeer-review

119 Citations (Scopus)

Abstract

In this work, the formation of lithium dendrites in lithium/Li4Ti5O12battery cells is studied using different experimental techniques. Electrochemical impedance spectroscopy is presented as a tool to investigate non-invasively the dendritic growth on a lithium metal surface in lithium/Li4Ti5O12cells during numerous discharging/charging cycles. Scanning electron microscopy is used for visual inspection of the dendrite formation. In situ7Li nuclear magnetic resonance spectroscopy is sensitive to quantitative changes at the lithium metal surface. Application to symmetrical lithium/lithium battery cells allows for a careful comparison of the investigated electrolytes. All these experimental methods provide consistent results. It is demonstrated that the growth of lithium dendrites is significantly correlated to the electrolyte employed. All electrolytes based on the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethane-sulfonyl)azanide (EMIM-TFSA) show reduced dendrite growth in comparison to the standard electrolyte for Li-ion batteries, lithium hexafluorophosphate (LiPF6) in ethylene carbonate/dimethyl carbonate (EC/DMC). LiPF6in EMIM-TFSA and LiPF6in EMIM-TFSA/propylene carbonate suppress lithium dendrites most efficiently.
Original languageEnglish
Pages (from-to)237-243
Number of pages7
JournalJournal of Power Sources
Volume228
DOIs
Publication statusPublished - 7 Jan 2013
Externally publishedYes

Keywords

  • Dendrite formation
  • Electrochemical impedance spectroscopy
  • Lithium metal
  • Lithium titanate
  • Nuclear magnetic resonance
  • Scanning electron microscopy

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Energy Engineering and Power Technology
  • Physical and Theoretical Chemistry
  • Electrical and Electronic Engineering

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