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arXiv · 1810.02039

Electronic structure and properties of lithium-rich complex oxides

Khang Hoang·Myungkeun Oh·Yongki Choi
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Abstract

Lithium-rich complex transition-metal oxides Li$_2$MoO$_3$, Li$_2$RuO$_3$, Li$_3$RuO$_4$, Li$_3$NbO$_4$, Li$_5$FeO$_4$, Li$_5$MnO$_4$ and their derivatives are of interest for high-capacity battery electrodes. Here, we report a first-principles density-functional theory study of the atomic and electronic structure of these materials using the Heyd-Scuseria-Ernzerhof (HSE) screened hybrid functional which treats all orbitals in the materials on equal footing. Dimerization of the transition-metal ions is found to occur in layered Li$_2$MoO$_3$, in both fully lithiated and partially delithiated compounds. The Ru--Ru dimerization does not occur in fully lithiated Li$_2$RuO$_3$, in contrast to what is commonly believed; Ru--Ru dimers are, however, found to occur in the presence of lithium vacancies caused by lithium loss during synthesis and/or lithium removal during use. We also analyze the electronic structure of the complex oxides and discuss the delithiation mechanism in these battery electrode materials.

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Khang Hoang, Myungkeun Oh, Yongki Choi. 2018-10-04. Electronic structure and properties of lithium-rich complex oxides. https://doi.org/10.1021/acsaelm.8b00025

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