Publication
Article Metrics
Citations
Online attention
Anion-polarisation–directed short-range-order in antiperovskite Li2FeSO
Authors:
Samuel W.
Coles
(University of Bath; The Faraday Institution)
,
Viktoria
Falkowski
(University of Oxford; The Faraday Institution)
,
Harry S.
Geddes
(University of Oxford; The Faraday Institution)
,
Gabriel E.
Pérez
(ISIS Neutron and Muon Source; The Faraday Institution)
,
Samuel G.
Booth
(University of Sheffield; The Faraday Institution)
,
Alexander G.
Squires
(University of Bath; University College London; The Faraday Institution)
,
Conn
O'Rourke
(University of Bath; The Faraday Institution)
,
Kit
Mccoll
(University of Bath; The Faraday Institution)
,
Andrew L.
Goodwin
(University of Oxford; University of Bath; The Faraday Institution)
,
Serena A.
Cussen
(University of Sheffield; The Faraday Institution)
,
Simon J.
Clarke
(University of Oxford; University of Bath; The Faraday Institution)
,
Saiful
Islam
(University of Bath; University of Oxford; The Faraday Institution)
,
Benjamin J.
Morgan
(University of Bath; The Faraday Institution)
Co-authored by industrial partner:
No
Type:
Journal Paper
Journal:
Journal Of Materials Chemistry A
State:
Published (Approved)
Published:
April 2023
Diamond Proposal Number(s):
27702
Abstract: Short-range ordering in cation-disordered cathodes can have a significant effect on their electrochemical properties. Here, we characterise the cation short-range order in the antiperovskite cathode material Li2FeSO, using density functional theory, Monte Carlo simulations, and synchrotron X-ray pair-distribution-function data. We predict partial short-range cation-ordering, characterised by favourable OLi4Fe2 oxygen coordination with a preference for polar cis-OLi4Fe2 over non-polar trans-OLi4Fe2 configurations. This preference for polar cation configurations produces long-range disorder, in agreement with experimental data. The predicted short-range-order preference contrasts with that for a simple point-charge model, which instead predicts preferential trans-OLi4Fe2 oxygen coordination and corresponding long-range crystallographic order. The absence of long-range order in Li2FeSO can therefore be attributed to the relative stability of cis-OLi4Fe2 and other non-OLi4Fe2 oxygen-coordination motifs. We show that this effect is associated with the polarisation of oxide and sulfide anions in polar coordination environments, which stabilises these polar short-range cation orderings. We propose similar anion-polarisation–directed short-range-ordering may be present in other heterocationic materials that contain cations with different formal charges. Our analysis also illustrates the limitations of using simple point-charge models to predict the structure of cation-disordered materials, where other factors, such as anion polarisation, may play a critical role in directing both short- and long-range structural correlations.
Subject Areas:
Materials,
Chemistry
Instruments:
I15-1-X-ray Pair Distribution Function (XPDF)
Added On:
19/04/2023 11:26
Documents:
d2ta10037a.pdf
Discipline Tags:
Physical Chemistry
Energy Materials
Chemistry
Materials Science
Technical Tags:
Scattering
Total Scattering