Feasible transformation of MgCo2O4 from spinel to defect rocksalt structure under electron irradiation

SCRIPTA MATERIALIA

卷:167

Article

Okamoto, Norihiko L.¹  Shimokawa, Kohei¹  Tanimura, Hiroshi¹  Ichitsubo, Tetsu¹ 

[1] Tohoku Univ, Inst Mat Res, Aoba Ku, 2-1-1 Katahira, Sendai, Miyagi 9808577, Japan

关键词: Diffusion;    Entropy;    Irradiation effect;    STEM HAADF;    Nudged elastic band (NEB) method;   

DOI  :  10.1016/j.scriptamat.2019.03.034

来源: Elsevier

【 摘 要 】

Spinel MgCo2O4 oxide, expected as a cathode material candidate for magnesium rechargeable battery, undergoes spinel-to-rocksalt transition accompanied with Mg insertion. Upon scanning-transmission-electron-microscopy observation, cations located at the tetrahedral sites readily migrate to the adjacent octahedral sites due to electron irradiation (without any Mg insertion), so that the spinel structure changes to a defect rocksalt structure with cation disorder. This together with first-principles calculations demonstrates that there is little energetic preference for Mg cation between the tetrahedral and octahedral sites, accounting for the feasibility of the Mg insertion into the spinel MgCo2O4 cathode via intercalation and push-out process of Mg cation. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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