Lithium-Ion Solvation Structure in Organic Carbonate Electrolytes at Low Temperatures

Yeongseok Chae, Chaiho Lim, Jonggu Jeon, Minju Kim, Kyung Koo Lee, Kyungwon Kwak, Minhaeng Cho

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Lithium-ion batteries face insufficient capacity at low temperatures. The lithium-ion desolvation process in the vicinity of a solid electrolyte interphase (SEI) layer is considered the major problem. Thus, an accurate determination of lithium-ion solvation structures is a prerequisite for understanding this process. Here, using a cryostat combined with an FTIR spectrometer, we found that as the temperature decreased, the number of coordinating carbonates in the first solvation shell of the lithium ion increased with a decreased population of the contact ion pair (CIP). More specifically, we found that two or more carbonate molecules replace a single PF6- anion upon CIP dissociation. This experimental finding shows that the prevailing notion that four carbonate molecules coordinate each lithium ion to form a tetrahedral structure is invalid for describing lithium-ion solvation structures. We anticipate that the present work will elucidate one of the molecular origins behind the low performance of lithium-ion batteries at low temperatures.

Original languageEnglish
Pages (from-to)7881-7888
Number of pages8
JournalJournal of Physical Chemistry Letters
Volume13
Issue number33
DOIs
Publication statusPublished - 2022 Aug 25

ASJC Scopus subject areas

  • Materials Science(all)
  • Physical and Theoretical Chemistry

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