Elucidating lithium-ion and proton dynamics in anti-perovskite solid electrolytes

Dawson, James A.; Attari, Tavleen S.; Chen, Hungru; Emge, Steffen P.; Johnston, Karen E.; Islam, M. Saiful

Abstract

All-solid-state Li-ion batteries are currently attracting considerable research attention as they present a viable opportunity for increased energy density and safety when compared to conventional liquid electrolyte-based devices. The Li-rich anti-perovskite Li3−xOHxCl has generated recent interest as a potential solid electrolyte material, but its lithium and proton transport capabilities as a function of composition are not fully characterised. In this work, we apply a combination of ab initio molecular dynamics and 1H, 2H and 7Li solid-state NMR spectroscopy to study the mobility of lithium ions and protons in Li3−xOHxCl. Our calculations predict a strongly exothermic hydration enthalpy for Li3OCl, which explains the ease with which this material absorbs moisture and the difficulty in synthesising moisture-free samples. We show that the activation energy for Li-ion conduction increases with increasing proton content. The atomistic simulations indicate fast Li-ion diffusion but rule out the contribution of long-range proton diffusion. These findings are supported by variable-temperature solid-state NMR experiments, which indicate localised proton motion and long-range Li-ion mobility that are intimately connected. Our findings confirm that Li3−xOHxCl is a promising solid electrolyte material for all-solid-state Li-ion batteries.

Citation

Dawson, J. A., Attari, T. S., Chen, H., Emge, S. P., Johnston, K. E., & Islam, M. S. (2018). Elucidating lithium-ion and proton dynamics in anti-perovskite solid electrolytes. Energy & Environmental Science, 11(10), 2993-3002. https://doi.org/10.1039/c8ee00779a

• Journal Article Type: Article
• Acceptance Date: Jul 30, 2018
• Online Publication Date: Jul 30, 2018
• Publication Date: Oct 31, 2018
• Deposit Date: Aug 23, 2018
• Publicly Available Date: Oct 11, 2018
• Journal: Energy & Environmental Science
• Print ISSN: 1754-5692
• Electronic ISSN: 1754-5706
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 11
• Issue: 10
• Pages: 2993-3002
• DOI: https://doi.org/10.1039/c8ee00779a
• Public URL: https://durham-repository.worktribe.com/output/1321488