Kinetically-Driven Phase Transformation during Lithiation in Copper Sulfide Nanoflakes

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review

26 Scopus Citations
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Author(s)

  • Kai He
  • Zhenpeng Yao
  • Sooyeon Hwang
  • Na Li
  • Ke Sun
  • Hong Gan
  • Yaping Du
  • Chris Wolverton
  • Dong Su

Detail(s)

Original languageEnglish
Pages (from-to)5726-5733
Journal / PublicationNano Letters
Volume17
Issue number9
Early online date11 Aug 2017
Publication statusPublished - 13 Sep 2017
Externally publishedYes

Abstract

Two-dimensional (2D) transition metal chalcogenides have been widely studied and utilized as electrode materials for lithium ion batteries due to their unique layered structures to accommodate reversible lithium insertion. Real-time observation and mechanistic understanding of the phase transformations during lithiation of these materials are critically important for improving battery performance by controlling structures and reaction pathways. Here, we use in situ transmission electron microscopy methods to study the structural, morphological, and chemical evolutions in individual copper sulfide (CuS) nanoflakes during lithiation. We report a highly kinetically driven phase transformation in which lithium ions rapidly intercalate into the 2D van der Waals-stacked interlayers in the initial stage, and further lithiation induces the Cu extrusion via a displacement reaction mechanism that is different from the typical conversion reactions. Density functional theory calculations have confirmed both the thermodynamically favored and the kinetically driven reaction pathways. Our findings elucidate the reaction pathways of the Li/CuS system under nonequilibrium conditions and provide valuable insight into the atomistic lithiation mechanisms of transition metal sulfides in general.

Research Area(s)

  • Copper sulfides, CuS, electrochemistry kinetics, in situ TEM, lithium ion battery

Citation Format(s)

Kinetically-Driven Phase Transformation during Lithiation in Copper Sulfide Nanoflakes. / He, Kai; Yao, Zhenpeng; Hwang, Sooyeon; Li, Na; Sun, Ke; Gan, Hong; Du, Yaping; Zhang, Hua; Wolverton, Chris; Su, Dong.

In: Nano Letters, Vol. 17, No. 9, 13.09.2017, p. 5726-5733.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review