DFT investigation of Ca mobility in reduced-perovskite and oxidized-marokite oxides

Torres, A.; Luque Del Villar, Francisco Javier; Tortajada, J.; Arroyo de Dompablo, M. E.

DFT investigation of Ca mobility in reduced-perovskite and oxidized-marokite oxides

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Official URL

https//doi.org/10.1016/j.ensm.2019.06.002

Publication date

2019

Authors

Torres, A.

Luque Del Villar, Francisco Javier

Tortajada, J.

Arroyo de Dompablo, M. E.

Publisher

Elsevier

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URI

https://hdl.handle.net/20.500.14352/13556

Citation

Torres, A., Luque, F. J., Tortajada, J., Arroyo de Dompablo, M. E. «DFT Investigation of Ca Mobility in Reduced-Perovskite and Oxidized-Marokite Oxides». Energy Storage Materials, vol. 21, septiembre de 2019, pp. 354-60. DOI.org (Crossref), https://doi.org/10.1016/j.ensm.2019.06.002.

Abstract

Progress in the development of rechargeable Ca-ion batteries demands the discovery of potential cathode materials. Transition metal oxides are interesting candidates due to their theoretical high energy densities, but with the drawback of a low Ca mobility. Previous computational/experimental investigations associate the electrochemical inactivity of various oxides (CaMO3-perovskite, CaMn2O4-post-spinel and CaV2O5) to high energy barriers for Ca migration. The introduction of oxygen and/or Ca vacancies in ternary transition metal oxides is a likely way to reshape the local topology and hence improve the Ca diffusivity. In this work, the energy barriers for Ca migration are calculated and discussed for (i) oxygen-deficient perovskites within the related Ca2Fe2O5-brownmillerite and Ca2Mn2O5 structures, and (ii) tunnel CaMn4O8, a derivative of the CaMn2O4-marokite with Ca vacancies.