Author(s): Jiao, JY (Jiao, Jianyue); Zhang, ZG (Zhang, Zhigang); Kuroiwa, Y (Kuroiwa, Yoshihiro); Zhao, EY (Zhao, Enyue); Yin, W (Yin, Wen); Wang, BT (Wang, Baotian); Wang, FW (Wang, Fangwei); Zhao, JK (Zhao, Jinkui); Zhang, XW (Zhang, Xingwang); Xiao, XL (Xiao, Xiaoling)

Source: CHEMICAL ENGINEERING JOURNAL Volume: 454 Article Number: 140327 DOI: 10.1016/j.cej.2022.140327 Part: 3 Published: FEB 15 2023

Abstract: Li-rich Li-Mn-O (LR-LMO) oxides are promising cathodes for low-lost and high-energy-density Li-ion batteries owing to their accessible anionic redox reaction (ARR) chemistry. However, the unstable ARR structure can result in inferior electrochemical properties, restricting practical applications of LR-LMO oxides. In this study, we demonstrate that the symmetry of locally ordered lattice can be tuned to enable robust ARR structure in LR-LMO cathodes. By employing a twofold symmetry locally ordered lattice in the LR-LMO oxide (denoted as tLR-LMO), a reversible capacity of 260 mAh/g at 0.1C and capacity retention of 78 % after 100 cycles at 1C were observed. The tLR-LMO has retarded cationic migrations during the ARR process when compared to this with a sixfold symmetry locally ordered lattice (denoted as sLR-LMO), as indicated by in-situ X-ray diffraction and ex-situ scanning transmission electron microscopy studies. The tLR-LMO also shows superior stability in its ARR structure as revealed by ex-situ X-ray absorption spectra and neutron pair distribution function results and supported by theoretical calculations. More broadly, this work highlights the role of local-structure symmetry in designing high-performance Li-rich cathodes with ARR activity.

Accession Number: WOS:000918226200001

ISSN: 1385-8947

eISSN: 1873-3212

Full Text: https://www.sciencedirect.com/science/article/pii/S1385894722058077?via%3Dihub