Design of Nanostructured Heterogeneous Solid Ionic Coatings through a Multiscale Defect Model

Jie Pan, Qinglin Zhang, Xingcheng Xiao, Yang Tse Cheng, Yue Qi

Research output: Contribution to journalArticle

  • 8 Citations

Abstract

Understanding of the electrical conduction, that is, ionic and electronic conduction, through the solid electrolyte interphase (SEI) is critical to the design of durable lithium-ion batteries (LIBs) with high rate capability and long life. It is believed that an ideal SEI should not only be an ionic conductor, but also an electronic insulator. In this study, we present a theoretical design of an artificial SEI consisting of lithium fluoride (LiF) and lithium carbonate (Li2CO3) on a LIB anode based on a newly developed density functional theory (DFT) informed space charge model. We demonstrate that the migration of lattice Li ions from LiF phase to form Li interstitials in Li2CO3 is energetically favorable near the LiF/Li2CO3 interface. At equilibrium, this interfacial defect reaction establishes a space charge potential across the interface, which causes the accumulation of ionic carriers but the depletion of electronic carriers near the LiF/Li2CO3 interface. To utilize this space charge effect, we propose a computationally designed, nanostructured artificial SEI structure with high density of interfaces of LiF and Li2CO3 perpendicular to the electrode. On the basis of this structure, the influences of grain size and volume ratio of the two phases were studied. Our results reveal that reducing the grain size of Li2CO3 in the nanostructured composite can promote ionic carriers and increase the ionic conductivity through the composite SEI by orders of magnitude. At the same time, the electronic conductivity is reduced due to electron depletion near the LiF/Li2CO3 interface. Furthermore, an optimal volume fraction that ensures high ionic and low electronic conduction was predicted.

LanguageEnglish (US)
Pages5687-5693
Number of pages7
JournalACS Applied Materials and Interfaces
Volume8
Issue number8
DOIs
StatePublished - Mar 2 2016

Profile

Carbon Monoxide
Lithium
Solid electrolytes
Coatings
Defects
Electric space charge
Lithium Carbonate
Composite materials
Ionic conductivity
Density functional theory
lithium fluoride
Carbonates
Volume fraction
Anodes
Ions
Electrodes
Electrons

Keywords

  • defect
  • density functional theory
  • heterogeneous interface
  • ionic conduction
  • solid electrolyte interphase
  • space charge

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Design of Nanostructured Heterogeneous Solid Ionic Coatings through a Multiscale Defect Model. / Pan, Jie; Zhang, Qinglin; Xiao, Xingcheng; Cheng, Yang Tse; Qi, Yue.

In: ACS Applied Materials and Interfaces, Vol. 8, No. 8, 02.03.2016, p. 5687-5693.

Research output: Contribution to journalArticle

Pan, Jie ; Zhang, Qinglin ; Xiao, Xingcheng ; Cheng, Yang Tse ; Qi, Yue. / Design of Nanostructured Heterogeneous Solid Ionic Coatings through a Multiscale Defect Model. In: ACS Applied Materials and Interfaces. 2016 ; Vol. 8, No. 8. pp. 5687-5693
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