Gamon, Jacinthe, Duff, Benjamin B, Dyer, Matthew S, Collins, Christopher, Daniels, Luke M, Surta, T Wesley, Sharp, Paul M, Gaultois, Michael W, Blanc, Frederic, Claridge, John Bleddyn et al (show 1 more authors)
(2019)
Computationally Guided Discovery of the Sulfide Li<sub>3</sub>AlS<sub>3</sub> in the Li-Al-S Phase Field: Structure and Lithium Conductivity.
CHEMISTRY OF MATERIALS, 31 (23).
pp. 9699-9714.
Abstract
With the goal of finding new lithium solid electrolytes by a combined computational-experimental method, the exploration of the Li-Al-O-S phase field resulted in the discovery of a new sulfide Li<sub>3</sub>AlS<sub>3</sub>. The structure of the new phase was determined through an approach combining synchrotron X-ray and neutron diffraction with <sup>6</sup>Li and <sup>27</sup>Al magic-angle spinning nuclear magnetic resonance spectroscopy and revealed to be a highly ordered cationic polyhedral network within a sulfide anion <i>hcp</i>-type sublattice. The originality of the structure relies on the presence of Al<sub>2</sub>S<sub>6</sub> repeating dimer units consisting of two edge-shared Al tetrahedra. We find that, in this structure type consisting of alternating tetrahedral layers with Li-only polyhedra layers, the formation of these dimers is constrained by the Al/S ratio of 1/3. Moreover, by comparing this structure to similar phases such as Li<sub>5</sub>AlS<sub>4</sub> and Li<sub>4.4</sub>Al<sub>0.2</sub>Ge<sub>0.3</sub>S<sub>4</sub> ((Al + Ge)/S = 1/4), we discovered that the AlS<sub>4</sub> dimers not only influence atomic displacements and Li polyhedral distortions but also determine the overall Li polyhedral arrangement within the <i>hcp</i> lattice, leading to the presence of highly ordered vacancies in both the tetrahedral and Li-only layer. AC impedance measurements revealed a low lithium mobility, which is strongly impacted by the presence of ordered vacancies. Finally, a composition-structure-property relationship understanding was developed to explain the extent of lithium mobility in this structure type.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | 40 Engineering, 4016 Materials Engineering, 34 Chemical Sciences |
| Depositing User: | Symplectic Admin |
| Date Deposited: | 10 Dec 2019 15:51 |
| Last Modified: | 20 Jun 2024 18:45 |
| DOI: | 10.1021/acs.chemmater.9b03230 |
| Open Access URL: | https://pubs.acs.org/doi/pdf/10.1021/acs.chemmater... |
| Related URLs: | |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3065784 |
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