Kobayashi Hiroaki, Tsukasaki Takashi, Ogasawara Yoshiyuki, Hibino Mitsuhiro, Kudo Tetsuichi, Mizuno Noritaka, Honma Itaru, Yamaguchi Kazuya
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi, 980-8577, Japan.
Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
ACS Appl Mater Interfaces. 2020 Sep 30;12(39):43605-43613. doi: 10.1021/acsami.0c10768. Epub 2020 Sep 21.
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 LiCoO cathode. This cubic phase is synthesized by a simple mechanochemical treatment of conventionally prepared tetragonal LiCoO. It displays a reversible capacity of 487 mAh g, a high value because of a reversible three-electron reaction using Co/Co, Co/Co, and O/O redox, occurring without O 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.
利用部分氧氧化还原的多电子反应电极材料因其具有诸多优势，包括高可逆容量、高能量密度和低成本等，有望用作锂离子电池的阴极。在此，通过阳离子无序反萤石型立方LiCoO阴极中反萤石与岩盐之间的拓扑相变，展示了一种可逆的三电子反应。这种立方相是通过对传统制备的四方LiCoO进行简单的机械化学处理合成的。它表现出487 mAh g的可逆容量，这是一个很高的值，因为利用Co/Co、Co/Co和O/O氧化还原发生了可逆的三电子反应，且没有氧气析出。机械化学处理被认为通过阳离子无序减少了其晶格畸变，并通过动态阳离子推动机制促进了反萤石和岩盐结构之间可逆的拓扑相变。
