Charge–Discharge Mechanism of High‐Entropy Co‐Free Spinel Oxide Toward Li + Storage Examined Using Operando Quick‐Scanning X‐Ray Absorption Spectroscopy
Name
Advanced Science - 2022 - Luo - Charge Discharge Mechanism of High‐Entropy Co‐Free Spinel Oxide Toward Li Storage Examined.pdf
Description
Published version
Size
7.3 MB
Format
Adobe PDF
Checksum (MD5)
eb5300981d49873ea57c72eff00c0cb4
Author(s)
Luo, Xu-Feng
Patra, Jagabandhu
Chuang, Wei-Tsung
Nguyen, Thi Xuyen
Ting, Jyh-Ming
Li, Ju
Pao, Chih-Wen
Chang, Jeng-Kuei
Date Issued
2022
Journal
Advanced Science
Publisher
Wiley
Citation
Luo, Xu-Feng, Patra, Jagabandhu, Chuang, Wei-Tsung, Nguyen, Thi Xuyen, Ting, Jyh-Ming et al. 2022. "Charge–Discharge Mechanism of High‐Entropy Co‐Free Spinel Oxide Toward Li + Storage Examined Using Operando Quick‐Scanning X‐Ray Absorption Spectroscopy." Advanced Science, 9 (21).
Version
Final published version
Abstract
Transition metal high-entropy oxides (HEOs) are an attractive class of anode materials for high-performance lithium-ion batteries (LIBs). However, owing to the multiple electroactive centers of HEOs, the Li+ storage mechanism is complex and debated in the literature. In this work, operando quick-scanning X-ray absorption spectroscopy (XAS) is used to study the lithiation/delithiation mechanism of the Cobalt-free spinel (CrMnFeNiCu)3 O4 HEO. A monochromator oscillation frequency of 2 Hz is used and 240 spectra are integrated to achieve a 2 min time resolution. High-photon-flux synchrotron radiation is employed to increase the XAS sensitivity. The results indicate that the Cu2+ and Ni2+ cations are reduced to their metallic states during lithiation but their oxidation reactions are less favorable compared to the other elements upon delithiation. The Mn2+/3+ and Fe2+/3+ cations undergo two-step conversion reactions to form metallic phases, with MnO and FeO as the intermediate species, respectively. During delithiation, the oxidation of Mn occurs prior to that of Fe. The Cr3+ cations are reduced to CrO and then Cr0 during lithiation. A relatively large overpotential is required to activate the Cr reoxidation reaction. The Cr3+ cations are found after delithiation. These results can guide the material design of HEOs for improving LIB performance.
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Terms of Use
Creative Commons Attribution 4.0 International license
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DOI of Published Version
https://doi.org/10.1002/ADVS.202201219
