The impact of oxygen vacancies on lithium vacancy formation and diffusion in Li2-xMnO3-δ

Christine James, Yan Wu, Brian W. Sheldon, Yue Qi

Research output: Contribution to journalArticle

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Abstract

High-capacity battery cathode materials containing Li2MnO3 appear to be activated during the first electrochemical cycle through the generation of oxygen vacancies. These oxygen vacancies have been predicted to alter the atomistic scale structure of Li2MnO3 and thus impact the delithiation process. In order to understand the effects of these oxygen vacancies we computationally determine the location of lithium removal in Li2MnO3-δ (δ = 0, 0.0625 and 0.125) and study lithium diffusion in Li2-xMnO3-δ. This study shows that it is energetically favorable for the lithium vacancies to form in the neighboring positions of the oxygen vacancies, suggesting that there is a strong interaction between the two vacancy types. This interaction also inhibits the diffusion of the lithium-ions, as seen in ab-initio molecular dynamics simulations where less hopping of lithium atoms is observed when oxygen vacancies are present. Additionally, the oxygen vacancy containing structures lead to an increase in the energy barrier for lithium and the calculated diffusion coefficient decreases by ∼ 5 orders of magnitude from the perfect crystal structure.

LanguageEnglish (US)
Pages87-94
Number of pages8
JournalSolid State Ionics
Volume289
DOIs
StatePublished - Jun 1 2016

Profile

Oxygen vacancies
Lithium
Vacancies
lithium
oxygen
Energy barriers
Molecular dynamics
Cathodes
Crystal structure
Ions
electric batteries
Atoms
diffusion coefficient
cathodes
Computer simulation
molecular dynamics
cycles
crystal structure
atoms

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Chemistry(all)

Cite this

The impact of oxygen vacancies on lithium vacancy formation and diffusion in Li2-xMnO3-δ . / James, Christine; Wu, Yan; Sheldon, Brian W.; Qi, Yue.

In: Solid State Ionics, Vol. 289, 01.06.2016, p. 87-94.

Research output: Contribution to journalArticle

James, Christine ; Wu, Yan ; Sheldon, Brian W. ; Qi, Yue. / The impact of oxygen vacancies on lithium vacancy formation and diffusion in Li2-xMnO3-δ In: Solid State Ionics. 2016 ; Vol. 289. pp. 87-94
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