Suppression of O-redox reactions by multivalent Cr in Li-excess Li2.4M0.8M0.8′O4 (M, M' = Cr, Mn, and Ti) cathodes with layered and cation-disordered rock-salt structures. (10th September 2020)

• Record Type: Journal Article
• Authors: Hamaguchi, Motoyuki; Momida, Hiroyoshi; Kitajou, Ayuko; Okada, Shigeto; Oguchi, Tamio
• Is Part Of: Electrochimica acta. Volume 354(2020)
• Publication Date: 2020-09-10
• Subjects: Li-ion battery -- Li-excess cation-disordered rock-salt cathode -- Oxygen redox -- First-principles calculation; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2020.136630
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: We study cathode properties of Li-excess Li 2.4 M 0.8 M 0.8 ′ O4 ( M, M '= Cr, Mn, and Ti) materials with layered and cation-disordered rock-salt structures by first-principles calculations. Results show that, as Li-removal amounts y increase in Li 2.4 - y M 0.8 M 0.8 ′ O4, local structures at a certain amount of cation sites change from octahedral to tetrahedral coordinations with O especially at Cr sites. Calculated voltage–capacity curves are consistent with experimental results, and it is found that Cr-redox reactions predominate in whole y ranges for ( M, M ') = (Cr, Mn) and (Cr, Ti), while Mn-redox and O-redox at low and high y regions, respectively, are dominated for ( M, M ') = (Mn, Ti). In the cathode materials with Cr, both O-redox and O2 -release reactions are found to be suppressed by multivalent Cr.