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Depth‐of‐Discharge Dependent Capacity Decay Induced by the Accumulation of Oxidized Lattice Oxygen in Li‐Rich Layered Oxide Cathode

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More and more basic practical application scenarios have been gradually ignored/disregarded, in fundamental research on rechargeable batteries, e.g. assessing cycle life under various depths‐of‐discharge (DODs). Herein, although benefit from the additional energy density introduced by anionic redox, we critically revealed that lithium‐rich layered oxide (LRLO) cathodes present anomalously poor capacity retention at low‐DOD cycling, which is essentially different from typical layered cathodes (e.g. NCM), and pose a formidable impediment to the practical application of LRLO. We systemically demonstrated that DOD‐dependent capacity decay is induced by the anionic redox and accumulation of oxidized lattice oxygen (Oⁿ⁻). Upon low‐DOD cycling, the accumulation of Oⁿ⁻ and the persistent presence of vacancies in the transition metal (TM) layer intensified the in‐plane migration of TM, exacerbating the expansion of vacancy clusters, which further facilitated detrimental out‐of‐plane TM migration. As a result, the aggravated structural degradation of LRLO at low‐DOD impeded reversible Li⁺ intercalation, resulting in rapid capacity decay. Furthermore, prolonged accumulation of Oⁿ⁻ persistently corroded the electrode‐electrolyte interface, especially negative for pouch‐type full‐cells with the shuttle effect. Once the “double‐edged sword” effect of anionic redox being elucidated under practical condition, corresponding modification strategies/routes would become distinct for accelerating the practical application of LRLO.
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Batteries
Depth-of-Discharge Dependent Capacity Decay Induced by the
Accumulation of Oxidized Lattice Oxygen in Li-Rich Layered Oxide
Cathode
Kang Zhang, Yilong Chen, Yuanlong Zhu, Qizheng Zheng, Yonglin Tang, Dongyan Yu,
Qirui Liu, Haiyan Luo, Jianhua Yin, Linhui Zeng, Wen Jiao, Na Liu, Qingsong Wang,
Lirong Zheng, Jing Zhang, Yongchen Wang, Baodan Zhang,* Yawen Yan,* Huan Huang,*
Chong-Heng Shen,* Yu Qiao,* and Shi-Gang Sun
Abstract: More and more basic practical application scenarios have been gradually ignored/disregarded, in fundamental
research on rechargeable batteries, e.g. assessing cycle life under various depths-of-discharge (DODs). Herein, although
benefit from the additional energy density introduced by anionic redox, we critically revealed that lithium-rich layered
oxide (LRLO) cathodes present anomalously poor capacity retention at low-DOD cycling, which is essentially different
from typical layered cathodes (e.g. NCM), and pose a formidable impediment to the practical application of LRLO. We
systemically demonstrated that DOD-dependent capacity decay is induced by the anionic redox and accumulation of
oxidized lattice oxygen (On). Upon low-DOD cycling, the accumulation of Onand the persistent presence of vacancies
in the transition metal (TM) layer intensified the in-plane migration of TM, exacerbating the expansion of vacancy
clusters, which further facilitated detrimental out-of-plane TM migration. As a result, the aggravated structural
degradation of LRLO at low-DOD impeded reversible Li+intercalation, resulting in rapid capacity decay. Furthermore,
prolonged accumulation of Onpersistently corroded the electrode-electrolyte interface, especially negative for pouch-
type full-cells with the shuttle effect. Once the “double-edged sword” effect of anionic redox being elucidated under
practical condition, corresponding modification strategies/routes would become distinct for accelerating the practical
application of LRLO.
Introduction
Lithium-rich layered oxide (LRLO) cathodes have unlocked
dual pathways of electrochemical activity by introducing
excess lithium into transition metal (TM) layers,[1] combining
traditional cationic (TM ions) redox with the additional
activation of oxygen-related anionic redox.[2] This approach
has significantly enhanced specific capacity (>300 mAh/g)
and energy density (>1000 Wh/kg), far surpassing currently
commercialized layered oxide cathodes, such as Li-
NixCoyMnzO2, LiMnO2, and LiCoO2, which have specific
capacities around 200 mAh/g).[3] The advantages of LRLO,
[*] K. Zhang, Y. Chen, Y. Zhu, Q. Zheng, Y. Tang, D. Yu, Q. Liu, H. Luo,
J. Yin, L. Zeng, B. Zhang, Y. Yan, Y. Qiao, S.-G. Sun
State Key Laboratory of Physical Chemistry of Solid Surfaces,
Collaborative Innovation Center of Chemistry for Energy Materials
(iChEM), Department of Chemistry, College of Chemistry and
Chemical Engineering
Xiamen University
Xiamen, 361005, P. R. China
E-mail: zbd@cqu.edu.cn
36520211151887@stu.xmu.edu.cn
yuqiao@xmu.edu.cn
W. Jiao, N. Liu, C.-H. Shen
Materials Innovation Department (MID), Contemporary Amperex
Technology Co., Limited (CATL)
Ningde, 352100, P. R. China
E-mail: ShenCH@catl.com
Q. Wang
Bavarian Center for Battery Technology, Department of Chemistry
University of Bayreuth
Bayreuth, 95447, Germany
L. Zheng, J. Zhang, H. Huang
Beijing Synchrotron Radiation Facility, Institute of High Energy
Physics
Chinese Academy of Sciences
Beijing 100049, P. R. China
E-mail: huanhuang@ihep.ac.cn
Y. Wang
Phylion Battery Co., Ltd
Suzhou, 215000, P. R. China
B. Zhang, S.-G. Sun
Center of Advanced Electrochemical Energy, Institute of Advanced
Interdisciplinary Studies, School of Chemistry and Chemical
Engineering
Chongqing University
Chongqing, 401331, P. R. China
E-mail: zbd@cqu.edu.cn
Angewandte
Chemie
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How to cite: Angew. Chem. Int. Ed. 2025,64, e202419909
doi.org/10.1002/anie.202419909
Angew. Chem. Int. Ed. 2025,64, e202419909 (1 of 12) © 2024 Wiley-VCH GmbH
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