In situ TEM investigation of congruent phase transition and structural evolution of nanostructured silicon/carbon anode for lithium ion batteries

Chong Min Wang, Xiaolin Li, Zhiguo Wang, Wu Xu, Jun Liu, Fei Gao, Libor Kovarik, Ji Guang Zhang, Jane Howe, David J. Burton, Zhongyi Liu, Xingcheng Xiao, Suntharampillai Thevuthasan, Donald R. Baer

Research output: Contribution to journalArticle

172 Citations (Scopus)

Abstract

It is well-known that upon lithiation, both crystalline and amorphous Si transform to an armorphous Li xSi phase, which subsequently crystallizes to a (Li, Si) crystalline compound, either Li 15Si 4 or Li 22Si 5. Presently, the detailed atomistic mechanism of this phase transformation and the degradation process in nanostructured Si are not fully understood. Here, we report the phase transformation characteristic and microstructural evolution of a specially designed amorphous silicon (a-Si) coated carbon nanofiber (CNF) composite during the charge/discharge process using in situ transmission electron microscopy and density function theory molecular dynamic calculation. We found the crystallization of Li 15Si 4 from amorphous Li xSi is a spontaneous, congruent phase transition process without phase separation or large-scale atomic motion, which is drastically different from what is expected from a classic nucleation and growth process. The a-Si layer is strongly bonded to the CNF and no spallation or cracking is observed during the early stages of cyclic charge/discharge. Reversible volume expansion/contraction upon charge/discharge is fully accommodated along the radial direction. However, with progressive cycling, damage in the form of surface roughness was gradually accumulated on the coating layer, which is believed to be the mechanism for the eventual capacity fade of the composite anode during long-term charge/discharge cycling.

Original languageEnglish
Pages (from-to)1624-1632
Number of pages9
JournalNano Letters
Volume12
Issue number3
DOIs
Publication statusPublished - 14 Mar 2012
Externally publishedYes

Fingerprint

Silicon
electric batteries
Anodes
Carbon nanofibers
anodes
Carbon
lithium
Phase transitions
Transmission electron microscopy
Amorphous silicon
transmission electron microscopy
carbon
silicon
Crystalline materials
amorphous silicon
phase transformations
ions
Microstructural evolution
Composite materials
Crystallization

Keywords

  • congruent phase transition
  • DFT-MD
  • in situ TEM
  • Li-ion battery
  • Si-coated carbon nanofiber anode

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Mechanical Engineering

Cite this

In situ TEM investigation of congruent phase transition and structural evolution of nanostructured silicon/carbon anode for lithium ion batteries. / Wang, Chong Min; Li, Xiaolin; Wang, Zhiguo; Xu, Wu; Liu, Jun; Gao, Fei; Kovarik, Libor; Zhang, Ji Guang; Howe, Jane; Burton, David J.; Liu, Zhongyi; Xiao, Xingcheng; Thevuthasan, Suntharampillai; Baer, Donald R.

In: Nano Letters, Vol. 12, No. 3, 14.03.2012, p. 1624-1632.

Research output: Contribution to journalArticle

Wang, CM, Li, X, Wang, Z, Xu, W, Liu, J, Gao, F, Kovarik, L, Zhang, JG, Howe, J, Burton, DJ, Liu, Z, Xiao, X, Thevuthasan, S & Baer, DR 2012, 'In situ TEM investigation of congruent phase transition and structural evolution of nanostructured silicon/carbon anode for lithium ion batteries', Nano Letters, vol. 12, no. 3, pp. 1624-1632. https://doi.org/10.1021/nl204559u
Wang, Chong Min ; Li, Xiaolin ; Wang, Zhiguo ; Xu, Wu ; Liu, Jun ; Gao, Fei ; Kovarik, Libor ; Zhang, Ji Guang ; Howe, Jane ; Burton, David J. ; Liu, Zhongyi ; Xiao, Xingcheng ; Thevuthasan, Suntharampillai ; Baer, Donald R. / In situ TEM investigation of congruent phase transition and structural evolution of nanostructured silicon/carbon anode for lithium ion batteries. In: Nano Letters. 2012 ; Vol. 12, No. 3. pp. 1624-1632.
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