Cation-Disorder-Assisted Reversible Topotactic Phase Transition between Antifluorite and Rocksalt Toward High-Capacity Lithium-Ion Batteries

Hiroaki Kobayashi; Takashi Tsukasaki; Yoshiyuki Ogasawara; Mitsuhiro Hibino; Tetsuichi Kudo; Noritaka Mizuno; Itaru Honma; Kazuya Yamaguchi

doi:10.1021/acsami.0c10768

Cation-Disorder-Assisted Reversible Topotactic Phase Transition between Antifluorite and Rocksalt Toward High-Capacity Lithium-Ion Batteries

ACS Appl Mater Interfaces. 2020 Sep 30;12(39):43605-43613. doi: 10.1021/acsami.0c10768. Epub 2020 Sep 21.

Authors

Hiroaki Kobayashi¹, Takashi Tsukasaki², Yoshiyuki Ogasawara², Mitsuhiro Hibino², Tetsuichi Kudo², Noritaka Mizuno², Itaru Honma¹, Kazuya Yamaguchi²

Affiliations

¹ Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan.
² Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.

PMID: 32886483
DOI: 10.1021/acsami.0c10768

Abstract

Multielectron reaction electrode materials using partial oxygen redox can be potentially used as cathodes in lithium-ion batteries, as they offer numerous advantages, including high reversible capacity and energy density and low cost. Here, a reversible three-electron reaction is demonstrated utilizing topotactic phase transition between antifluorite and rocksalt in a cation-disordered antifluorite-type cubic Li₆CoO₄ cathode. This cubic phase is synthesized by a simple mechanochemical treatment of conventionally prepared tetragonal Li₆CoO₄. It displays a reversible capacity of 487 mAh g^-1, a high value because of a reversible three-electron reaction using Co²⁺/Co³⁺, Co³⁺/Co⁴⁺, and O^2-/O₂^2- redox, occurring without O₂ gas evolution. The mechanochemical treatment is assumed to reduce its lattice distortion by cation-disordering and facilitate a reversible topotactic phase transition between antifluorite and rocksalt structures via a dynamic cation pushing mechanism.

Keywords: antifluorite; cation-disorder; high-capacity cathode; lithium-ion battery; solid-state oxygen redox; topotactic phase transition.