The influence of Li deficiency: An overlooked factor that determines the anion redox reversibility of Mn-based layered oxide cathodes

Hui Liu; Xiang Wu; Xiaobing Lou; Wei Tong; Jiong Li; Bingwen Hu; Chao Li

doi:10.1016/j.ensm.2023.103058

The influence of Li deficiency: An overlooked factor that determines the anion redox reversibility of Mn-based layered oxide cathodes

Hui Liu, Xiang Wu, Xiaobing Lou, Wei Tong, Jiong Li, Bingwen Hu, Chao Li

Research output: Contribution to journal › Article › peer-review

7 Scopus citations

Abstract

The paradigm shift from O3-type structure to O2-type has been extensively proposed as a viable strategy to eliminating/mitigating lattice displacement and voltage decay faced by conventional Li-rich layered oxides. However, the influence of Li deficiency in pristine structure on the reversibility of anionic redox has been overlooked. Herein, we demonstrate that the O2-type structure is not always a better choice in achieving stable anionic redox than that of the O3-type Mn-based layered oxides by investigating two closely related O2- and O3-Li_0.6[Li_0.2Mn_0.8]O₂ materials with plenty of Li deficiency in pristine structure. Through the suites of characterizations including Mn K-edge XANES/EXAFS, ⁷Li pj-MATPASS NMR and Raman spectroscopies, we substantiate the poorer reversibility of the local structural transformation around Mn and Li upon cycling for O2-Li_0.6[Li_0.2Mn_0.8]O₂ in comparison with that of O3-Li_0.6[Li_0.2Mn_0.8]O₂ (within 2.0–4.8 V). Besides, irreversible out-of-plane transition metal migration occurs in O2-Li_0.6[Li_0.2Mn_0.8]O₂ while such process is dramatically suppressed in O3-Li_0.6[Li_0.2Mn_0.8]O₂. Our results indicate that in addition to the oxygen stacking sequence, the Li deficiency in pristine structure is also a decisive factor that influences the reversibility of anionic redox in layered oxides.

Original language	English
Article number	103058
Journal	Energy Storage Materials
Volume	63
DOIs	https://doi.org/10.1016/j.ensm.2023.103058
State	Published - Nov 2023
Externally published	Yes

Keywords

Anion redox
Ion exchange
Layered oxides
Li deficiency
Local structure

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1016/j.ensm.2023.103058

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@article{03574966a8bc46d3a143c1d7026db93c,

title = "The influence of Li deficiency: An overlooked factor that determines the anion redox reversibility of Mn-based layered oxide cathodes",

abstract = "The paradigm shift from O3-type structure to O2-type has been extensively proposed as a viable strategy to eliminating/mitigating lattice displacement and voltage decay faced by conventional Li-rich layered oxides. However, the influence of Li deficiency in pristine structure on the reversibility of anionic redox has been overlooked. Herein, we demonstrate that the O2-type structure is not always a better choice in achieving stable anionic redox than that of the O3-type Mn-based layered oxides by investigating two closely related O2- and O3-Li0.6[Li0.2Mn0.8]O2 materials with plenty of Li deficiency in pristine structure. Through the suites of characterizations including Mn K-edge XANES/EXAFS, 7Li pj-MATPASS NMR and Raman spectroscopies, we substantiate the poorer reversibility of the local structural transformation around Mn and Li upon cycling for O2-Li0.6[Li0.2Mn0.8]O2 in comparison with that of O3-Li0.6[Li0.2Mn0.8]O2 (within 2.0–4.8 V). Besides, irreversible out-of-plane transition metal migration occurs in O2-Li0.6[Li0.2Mn0.8]O2 while such process is dramatically suppressed in O3-Li0.6[Li0.2Mn0.8]O2. Our results indicate that in addition to the oxygen stacking sequence, the Li deficiency in pristine structure is also a decisive factor that influences the reversibility of anionic redox in layered oxides.",

keywords = "Anion redox, Ion exchange, Layered oxides, Li deficiency, Local structure",

author = "Hui Liu and Xiang Wu and Xiaobing Lou and Wei Tong and Jiong Li and Bingwen Hu and Chao Li",

note = "Publisher Copyright: {\textcopyright} 2023 Elsevier B.V.",

year = "2023",

month = nov,

doi = "10.1016/j.ensm.2023.103058",

language = "英语",

volume = "63",

journal = "Energy Storage Materials",

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TY - JOUR

T1 - The influence of Li deficiency

T2 - An overlooked factor that determines the anion redox reversibility of Mn-based layered oxide cathodes

AU - Liu, Hui

AU - Wu, Xiang

AU - Lou, Xiaobing

AU - Tong, Wei

AU - Li, Jiong

AU - Hu, Bingwen

AU - Li, Chao

PY - 2023/11

Y1 - 2023/11

N2 - The paradigm shift from O3-type structure to O2-type has been extensively proposed as a viable strategy to eliminating/mitigating lattice displacement and voltage decay faced by conventional Li-rich layered oxides. However, the influence of Li deficiency in pristine structure on the reversibility of anionic redox has been overlooked. Herein, we demonstrate that the O2-type structure is not always a better choice in achieving stable anionic redox than that of the O3-type Mn-based layered oxides by investigating two closely related O2- and O3-Li0.6[Li0.2Mn0.8]O2 materials with plenty of Li deficiency in pristine structure. Through the suites of characterizations including Mn K-edge XANES/EXAFS, 7Li pj-MATPASS NMR and Raman spectroscopies, we substantiate the poorer reversibility of the local structural transformation around Mn and Li upon cycling for O2-Li0.6[Li0.2Mn0.8]O2 in comparison with that of O3-Li0.6[Li0.2Mn0.8]O2 (within 2.0–4.8 V). Besides, irreversible out-of-plane transition metal migration occurs in O2-Li0.6[Li0.2Mn0.8]O2 while such process is dramatically suppressed in O3-Li0.6[Li0.2Mn0.8]O2. Our results indicate that in addition to the oxygen stacking sequence, the Li deficiency in pristine structure is also a decisive factor that influences the reversibility of anionic redox in layered oxides.

AB - The paradigm shift from O3-type structure to O2-type has been extensively proposed as a viable strategy to eliminating/mitigating lattice displacement and voltage decay faced by conventional Li-rich layered oxides. However, the influence of Li deficiency in pristine structure on the reversibility of anionic redox has been overlooked. Herein, we demonstrate that the O2-type structure is not always a better choice in achieving stable anionic redox than that of the O3-type Mn-based layered oxides by investigating two closely related O2- and O3-Li0.6[Li0.2Mn0.8]O2 materials with plenty of Li deficiency in pristine structure. Through the suites of characterizations including Mn K-edge XANES/EXAFS, 7Li pj-MATPASS NMR and Raman spectroscopies, we substantiate the poorer reversibility of the local structural transformation around Mn and Li upon cycling for O2-Li0.6[Li0.2Mn0.8]O2 in comparison with that of O3-Li0.6[Li0.2Mn0.8]O2 (within 2.0–4.8 V). Besides, irreversible out-of-plane transition metal migration occurs in O2-Li0.6[Li0.2Mn0.8]O2 while such process is dramatically suppressed in O3-Li0.6[Li0.2Mn0.8]O2. Our results indicate that in addition to the oxygen stacking sequence, the Li deficiency in pristine structure is also a decisive factor that influences the reversibility of anionic redox in layered oxides.

KW - Anion redox

KW - Ion exchange

KW - Layered oxides

KW - Li deficiency

KW - Local structure

UR - https://www.scopus.com/pages/publications/85177735183

U2 - 10.1016/j.ensm.2023.103058

DO - 10.1016/j.ensm.2023.103058

M3 - 文章

AN - SCOPUS:85177735183

SN - 2405-8297

VL - 63

JO - Energy Storage Materials

JF - Energy Storage Materials

M1 - 103058

ER -

The influence of Li deficiency: An overlooked factor that determines the anion redox reversibility of Mn-based layered oxide cathodes

Abstract

Keywords

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