Jump to main content
Jump to site search

Issue 48, 2015
Previous Article Next Article

Defect chemistry and lithium transport in Li3OCl anti-perovskite superionic conductors

Author affiliations

Abstract

Lithium-rich anti-perovskites (LiRAPs) are a promising family of solid electrolytes, which exhibit ionic conductivities above 10−3 S cm−1 at room temperature, among the highest reported values to date. In this work, we investigate the defect chemistry and the associated lithium transport in Li3OCl, a prototypical LiRAP, using ab initio density functional theory (DFT) calculations and classical molecular dynamics (MD) simulations. We studied three types of charge neutral defect pairs, namely the LiCl Schottky pair, the Li2O Schottky pair, and the Li interstitial with a substitutional defect of O on the Cl site. Among them the LiCl Schottky pair has the lowest binding energy and is the most energetically favorable for diffusion as computed by DFT. This is confirmed by classical MD simulations, where the computed Li ion diffusion coefficients for LiCl Schottky systems are significantly higher than those for the other two defects considered and the activation energy in LiCl deficient Li3OCl is comparable to experimental values. The high conductivities and low activation energies of LiCl Schottky systems are explained by the low energy pathways of Li between the Cl vacancies. We propose that Li vacancy hopping is the main diffusion mechanism in highly conductive Li3OCl.

Graphical abstract: Defect chemistry and lithium transport in Li3OCl anti-perovskite superionic conductors

Back to tab navigation

Supplementary files

Publication details

The article was received on 24 Sep 2015, accepted on 27 Oct 2015 and first published on 28 Oct 2015


Article type: Paper
DOI: 10.1039/C5CP05722A
Author version available: Download Author version (PDF)
Citation: Phys. Chem. Chem. Phys., 2015,17, 32547-32555
  •   Request permissions

    Defect chemistry and lithium transport in Li3OCl anti-perovskite superionic conductors

    Z. Lu, C. Chen, Z. M. Baiyee, X. Chen, C. Niu and F. Ciucci, Phys. Chem. Chem. Phys., 2015, 17, 32547
    DOI: 10.1039/C5CP05722A

Search articles by author

Spotlight

Advertisements