Tuning the Electronic, Ion Transport, and Stability Properties of Li-rich Manganese-based Oxide Materials with Oxide Perovskite Coatings: A First-Principles Computational Study

Zizhen Zhou; Dewei Chu; Bo Gao; Toshiyuki Momma; Yoshitaka Tateyama; Claudio Cazorla

doi:10.1021/acsami.2c07560

Tuning the Electronic, Ion Transport, and Stability Properties of Li-rich Manganese-based Oxide Materials with Oxide Perovskite Coatings: A First-Principles Computational Study

ACS Appl Mater Interfaces. 2022 Aug 17;14(32):37009-37018. doi: 10.1021/acsami.2c07560. Epub 2022 Aug 5.

Authors

Zizhen Zhou^{1

2

3}, Dewei Chu¹, Bo Gao³, Toshiyuki Momma², Yoshitaka Tateyama^{2

3}, Claudio Cazorla⁴

Affiliations

¹ School of Materials Science and Engineering, UNSW Australia, Sydney, NSW 2052, Australia.
² Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
³ Center for Green Research on Energy and Environmental Materials (GREEN) and International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
⁴ Departament de Física, Universitat Politècnica de Catalunya, Campus Nord B4-B5, E-08034 Barcelona, Spain.

Abstract

Lithium-rich manganese-based oxides (LRMO) are regarded as promising cathode materials for powering electric applications due to their high capacity (250 mAh g^-1) and energy density (∼900 Wh kg^-1). However, poor cycle stability and capacity fading have impeded the commercialization of this family of materials as battery components. Surface modification based on coating has proven successful in mitigating some of these problems, but a microscopic understanding of how such improvements are attained is still lacking, thus impeding systematic and rational design of LRMO-based cathodes. In this work, first-principles density functional theory (DFT) calculations are carried out to fill out such a knowledge gap and to propose a promising LRMO-coating material. It is found that SrTiO₃ (STO), an archetypal and highly stable oxide perovskite, represents an excellent coating material for Li_1.2Ni_0.2Mn_0.6O₂ (LNMO), a prototypical member of the LRMO family. An accomplished atomistic model is constructed to theoretically estimate the structural, electronic, oxygen vacancy formation energy, and lithium-transport properties of the LNMO/STO interface system, thus providing insightful comparisons with the two integrating bulk materials. It is found that (i) electronic transport in the LNMO cathode is enhanced due to partial closure of the LNMO band gap (∼0.4 eV) and (ii) the lithium ions can easily diffuse near the LNMO/STO interface and within STO due to the small size of the involved ion-hopping energy barriers. Furthermore, the formation energy of oxygen vacancies notably increases close to the LNMO/STO interface, thus indicating a reduction in oxygen loss at the cathode surface and a potential inhibition of undesirable structural phase transitions. This theoretical work therefore opens up new routes for the practical improvement of cost-affordable lithium-rich cathode materials based on highly stable oxide perovskite coatings.

Keywords: Li-rich manganese-based cathode; density functional theory; interface modeling; ionic diffusion; lithium battery; oxide perovskite.