Enhancement of Low Temperature Superionic Conductivity by Suppression of Li Site Ordering in Li 7 Si 2-x Ge x S 7 I.

Autor: Han G; Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom., Daniels LM; Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom., Vasylenko A; Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom., Morrison KA; Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom., Corti L; Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom.; Leverhulme Research Centre for Functional Materials Design, Materials Innovation Factory, University of Liverpool, 51 Oxford Street, Liverpool, L7 3NY, United Kingdom., Collins CM; Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom.; Leverhulme Research Centre for Functional Materials Design, Materials Innovation Factory, University of Liverpool, 51 Oxford Street, Liverpool, L7 3NY, United Kingdom., Niu H; Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom., Chen R; Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom., Roberston CM; Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom., Blanc F; Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom.; Leverhulme Research Centre for Functional Materials Design, Materials Innovation Factory, University of Liverpool, 51 Oxford Street, Liverpool, L7 3NY, United Kingdom.; Stephenson Institute for Renewable Energy, University of Liverpool, Peach Street, Liverpool, L69 7ZF, United Kingdom., Dyer MS; Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom.; Leverhulme Research Centre for Functional Materials Design, Materials Innovation Factory, University of Liverpool, 51 Oxford Street, Liverpool, L7 3NY, United Kingdom., Claridge JB; Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom.; Leverhulme Research Centre for Functional Materials Design, Materials Innovation Factory, University of Liverpool, 51 Oxford Street, Liverpool, L7 3NY, United Kingdom., Rosseinsky MJ; Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom.; Leverhulme Research Centre for Functional Materials Design, Materials Innovation Factory, University of Liverpool, 51 Oxford Street, Liverpool, L7 3NY, United Kingdom.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2024 Sep 09; Vol. 63 (37), pp. e202409372. Date of Electronic Publication: 2024 Aug 12.
DOI: 10.1002/anie.202409372
Abstrakt: Ge 4+ substitution into the recently discovered superionic conductor Li 7 Si 2 S 7 I is demonstrated by synthesis of Li 7 Si 2-x Ge x S 7 I, where x≤1.2. The anion packing and tetrahedral silicon location of Li 7 Si 2 S 7 I are retained upon substitution. Single crystal X-ray diffraction shows that substitution of larger Ge 4+ for Si 4+ expands the unit cell volume and further increases Li + site disorder, such that Li 7 Si 0.88 Ge 1.12 S 7 I has one Li + site more (sixteen in total) than Li 7 Si 2 S 7 I. The ionic conductivity of Li 7 Si 0.8 Ge 1.2 S 7 I (x=1.2) at 303 K is 1.02(3)×10 -2  S cm -1 with low activation energies for Li + transport demonstrated over a wide temperature range by AC impedance and 7 Li NMR spectroscopy. All sixteen Li + sites remain occupied to temperatures as low as 30 K in Li 7 Si 0.88 Ge 1.12 S 7 I as a result of the structural expansion. This differs from Li 7 Si 2 S 7 I, where the partial Li + site ordering observed below room temperature reduces the ionic conductivity. The suppression of Li + site depopulation by Ge 4+ substitution retains the high mobility to temperatures as low as 200 K, yielding low temperature performance comparable with state-of-the-art Li + ion conducting materials.
(© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)
Databáze: MEDLINE
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