Perez, Arnaud J, Vasylenko, Andrij ORCID: 0000-0002-6933-0628, Surta, T Wesley ORCID: 0000-0002-2882-6483, Niu, Hongjun, Daniels, Luke M ORCID: 0000-0002-7077-6125, Hardwick, Laurence J ORCID: 0000-0001-8796-685X, Dyer, Matthew S ORCID: 0000-0002-4923-3003, Claridge, John B ORCID: 0000-0003-4849-6714 and Rosseinsky, Matthew J ORCID: 0000-0002-1910-2483
(2021)
Ordered Oxygen Vacancies in the Lithium-Rich Oxide Li<sub>4</sub>CuSbO<sub>5.5</sub>, a Triclinic Structure Type Derived from the Cubic Rocksalt Structure.
INORGANIC CHEMISTRY, 60 (24).
pp. 19022-19034.
Abstract
Li-rich rocksalt oxides are promising candidates as high-energy density cathode materials for next-generation Li-ion batteries because they present extremely diverse structures and compositions. Most reported materials in this family contain as many cations as anions, a characteristic of the ideal cubic closed-packed rocksalt composition. In this work, a new rocksalt-derived structure type is stabilized by selecting divalent Cu and pentavalent Sb cations to favor the formation of oxygen vacancies during synthesis. The structure and composition of the oxygen-deficient Li<sub>4</sub>CuSbO<sub>5.5</sub>□<sub>0.5</sub> phase is characterized by combining X-ray and neutron diffraction, ICP-OES, XAS, and magnetometry measurements. The ordering of cations and oxygen vacancies is discussed in comparison with the related Li<sub>2</sub>CuO<sub>2</sub>□<sub>1</sub> and Li<sub>5</sub>SbO<sub>5</sub>□<sub>1</sub> phases. The electrochemical properties of this material are presented, with only 0.55 Li<sup>+</sup> extracted upon oxidation, corresponding to a limited utilization of cationic and/or anionic redox, whereas more than 2 Li<sup>+</sup> ions can be reversibly inserted upon reduction to 1 V vs Li<sup>+</sup>/Li, a large capacity attributed to a conversion reaction and the reduction of Cu<sup>2+</sup> to Cu<sup>0</sup>. Control of the formation of oxygen vacancies in Li-rich rocksalt oxides by selecting appropriate cations and synthesis conditions affords a new route for tuning the electrochemical properties of cathode materials for Li-ion batteries. Furthermore, the development of material models of the required level of detail to predict phase diagrams and electrochemical properties, including oxygen release in Li-rich rocksalt oxides, still relies on the accurate prediction of crystal structures. Experimental identification of new accessible structure types stabilized by oxygen vacancies represents a valuable step forward in the development of predictive models.
Item Type: | Article |
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Uncontrolled Keywords: | 7 Affordable and Clean Energy |
Divisions: | Faculty of Science and Engineering > School of Physical Sciences |
Depositing User: | Symplectic Admin |
Date Deposited: | 20 Jan 2022 10:36 |
Last Modified: | 14 Mar 2024 21:34 |
DOI: | 10.1021/acs.inorgchem.1c02882 |
Open Access URL: | https://doi.org/10.1021/acs.inorgchem.1c02882 |
Related URLs: | |
URI: | https://livrepository.liverpool.ac.uk/id/eprint/3147255 |