Structural evolution dependency on depth-of-discharge in VO2(B) Li-ion battery electrodes

Andreas Østergaard Drejer; Bettina Pilgaard Andersen; Dorthe Bomholdt Ravnsbæk

doi:10.1016/j.jpowsour.2022.232435

Structural evolution dependency on depth-of-discharge in VO₂(B) Li-ion battery electrodes

Andreas Østergaard Drejer, Bettina Pilgaard Andersen, Dorthe Bomholdt Ravnsbæk^*

^*Corresponding author af dette arbejde

Institut for Kemi

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avis › Tidsskriftartikel › Forskning › peer review

3 Citationer (Scopus)

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Abstract

Bronze vanadium oxide, VO₂(B), has gained significant interest as electrode for Li-ion mainly due to the ease of preparation and the experimentally obtainable capacities of >325 mAh g⁻¹ with intercalation of >1Li. In this work, we investigate for the first time the effects of intercalating >0.5Li on the structural phase evolution. Using operando X-ray diffraction, we find that deep discharge (i.e. inserting >0.7Li), has a dramatic effect on the subsequent charge process by introducing significant solid-solution behavior in the two-phase transition between the Li-rich and Li-poor phases. Rietveld refinement shows that the discharge-charge asymmetry is caused by severe structural deformations in the Li-rich state. Furthermore, we find that deep discharge causes capacity fade. This appears to be linked to the structural deformation causing an irreversible decrease in the Li-ion diffusion coefficients, determined herein by galvanostatic intermittent titrations.

Originalsprog	Engelsk
Artikelnummer	232435
Tidsskrift	Journal of Power Sources
Vol/bind	556
Antal sider	10
ISSN	0378-7753
DOI	https://doi.org/10.1016/j.jpowsour.2022.232435
Status	Udgivet - feb. 2023

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10.1016/j.jpowsour.2022.232435Licens: CC BY

1-s2.0-S0378775322014124-mainForlagets udgivne version, 9,18 MBLicens: CC BY

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@article{e74de691d3f446118748fb53d9caeb6f,

title = "Structural evolution dependency on depth-of-discharge in VO2(B) Li-ion battery electrodes",

abstract = "Bronze vanadium oxide, VO2(B), has gained significant interest as electrode for Li-ion mainly due to the ease of preparation and the experimentally obtainable capacities of >325 mAh g−1 with intercalation of >1Li. In this work, we investigate for the first time the effects of intercalating >0.5Li on the structural phase evolution. Using operando X-ray diffraction, we find that deep discharge (i.e. inserting >0.7Li), has a dramatic effect on the subsequent charge process by introducing significant solid-solution behavior in the two-phase transition between the Li-rich and Li-poor phases. Rietveld refinement shows that the discharge-charge asymmetry is caused by severe structural deformations in the Li-rich state. Furthermore, we find that deep discharge causes capacity fade. This appears to be linked to the structural deformation causing an irreversible decrease in the Li-ion diffusion coefficients, determined herein by galvanostatic intermittent titrations.",

keywords = "Cyclic voltammetry, Galvanostatic intermittent titration technique, Li-ion batteries, Operando synchrotron PXRD, Phase transition, Structural distortion, VO(B)",

author = "Drejer, {Andreas {\O}stergaard} and Andersen, {Bettina Pilgaard} and Ravnsb{\ae}k, {Dorthe Bomholdt}",

note = "Funding Information: SEM of the as-synthesized material (Fig. 2) shows rod shaped particles with an average length and width of 0.78 × 0.11 μm, respectively, in agreement with earlier reports on materials prepared using the same synthesis route [31]. Rietveld refinement of the SR-PXRD data for the as-synthesized material (Fig. 3A) confirms that the desired VO2(B) is obtained in a phase pure well crystalline state. The VO2(B) structure (Fig. 1) consists of edge-sharing VO6 sheets, octahedrally linked through corner-sharing to adjacent sheets along the c-direction in the unit cell, which creates empty cavities in form of 1D channels along both the b- and c-axis, where Li-ions can be intercalated [16]. Structural details of the refined VO2(B) structure are given in the supporting information (SI) in Table S1. The mean crystallite size was determined from peak broadening to 63(11) nm. The crystallite size obtained from Rietveld refinement is close to the observed width of the particles in the SEM images and could correspond to the cross section of the rods.We thank the Danish Ministry of Higher Education and Science for funding this project through the ESS Lighthouse SMART. We also acknowledge Danscatt for funding travel costs related to the synchrotron experiments. The authors acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for provision of experimental facilities at PETRA III and would like to thank Dr. Alexander Sch{\"o}kel for assistance in using beamline P02.1 [62]. The Carlsberg Foundation is acknowledged for funding the Tescan Clara SEM used in this work. Lastly, we gratefully acknowledge Martin Aaskov Karlsen for his Python based script for analysis of GITT data. The script was used to calculate the estimated diffusion coefficients. Funding Information: We thank the Danish Ministry of Higher Education and Science for funding this project through the ESS Lighthouse SMART. We also acknowledge Danscatt for funding travel costs related to the synchrotron experiments. The authors acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for provision of experimental facilities at PETRA III and would like to thank Dr. Alexander Sch{\"o}kel for assistance in using beamline P02.1 [ 62 ]. The Carlsberg Foundation is acknowledged for funding the Tescan Clara SEM used in this work. Lastly, we gratefully acknowledge Martin Aaskov Karlsen for his Python based script for analysis of GITT data. The script was used to calculate the estimated diffusion coefficients. Publisher Copyright: {\textcopyright} 2022 The Authors",

year = "2023",

month = feb,

doi = "10.1016/j.jpowsour.2022.232435",

language = "English",

volume = "556",

journal = "Journal of Power Sources",

issn = "0378-7753",

publisher = "Elsevier B.V.",

}

TY - JOUR

T1 - Structural evolution dependency on depth-of-discharge in VO2(B) Li-ion battery electrodes

AU - Drejer, Andreas Østergaard

AU - Andersen, Bettina Pilgaard

AU - Ravnsbæk, Dorthe Bomholdt

N1 - Funding Information: SEM of the as-synthesized material (Fig. 2) shows rod shaped particles with an average length and width of 0.78 × 0.11 μm, respectively, in agreement with earlier reports on materials prepared using the same synthesis route [31]. Rietveld refinement of the SR-PXRD data for the as-synthesized material (Fig. 3A) confirms that the desired VO2(B) is obtained in a phase pure well crystalline state. The VO2(B) structure (Fig. 1) consists of edge-sharing VO6 sheets, octahedrally linked through corner-sharing to adjacent sheets along the c-direction in the unit cell, which creates empty cavities in form of 1D channels along both the b- and c-axis, where Li-ions can be intercalated [16]. Structural details of the refined VO2(B) structure are given in the supporting information (SI) in Table S1. The mean crystallite size was determined from peak broadening to 63(11) nm. The crystallite size obtained from Rietveld refinement is close to the observed width of the particles in the SEM images and could correspond to the cross section of the rods.We thank the Danish Ministry of Higher Education and Science for funding this project through the ESS Lighthouse SMART. We also acknowledge Danscatt for funding travel costs related to the synchrotron experiments. The authors acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for provision of experimental facilities at PETRA III and would like to thank Dr. Alexander Schökel for assistance in using beamline P02.1 [62]. The Carlsberg Foundation is acknowledged for funding the Tescan Clara SEM used in this work. Lastly, we gratefully acknowledge Martin Aaskov Karlsen for his Python based script for analysis of GITT data. The script was used to calculate the estimated diffusion coefficients. Funding Information: We thank the Danish Ministry of Higher Education and Science for funding this project through the ESS Lighthouse SMART. We also acknowledge Danscatt for funding travel costs related to the synchrotron experiments. The authors acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for provision of experimental facilities at PETRA III and would like to thank Dr. Alexander Schökel for assistance in using beamline P02.1 [ 62 ]. The Carlsberg Foundation is acknowledged for funding the Tescan Clara SEM used in this work. Lastly, we gratefully acknowledge Martin Aaskov Karlsen for his Python based script for analysis of GITT data. The script was used to calculate the estimated diffusion coefficients. Publisher Copyright: © 2022 The Authors

PY - 2023/2

Y1 - 2023/2

N2 - Bronze vanadium oxide, VO2(B), has gained significant interest as electrode for Li-ion mainly due to the ease of preparation and the experimentally obtainable capacities of >325 mAh g−1 with intercalation of >1Li. In this work, we investigate for the first time the effects of intercalating >0.5Li on the structural phase evolution. Using operando X-ray diffraction, we find that deep discharge (i.e. inserting >0.7Li), has a dramatic effect on the subsequent charge process by introducing significant solid-solution behavior in the two-phase transition between the Li-rich and Li-poor phases. Rietveld refinement shows that the discharge-charge asymmetry is caused by severe structural deformations in the Li-rich state. Furthermore, we find that deep discharge causes capacity fade. This appears to be linked to the structural deformation causing an irreversible decrease in the Li-ion diffusion coefficients, determined herein by galvanostatic intermittent titrations.

AB - Bronze vanadium oxide, VO2(B), has gained significant interest as electrode for Li-ion mainly due to the ease of preparation and the experimentally obtainable capacities of >325 mAh g−1 with intercalation of >1Li. In this work, we investigate for the first time the effects of intercalating >0.5Li on the structural phase evolution. Using operando X-ray diffraction, we find that deep discharge (i.e. inserting >0.7Li), has a dramatic effect on the subsequent charge process by introducing significant solid-solution behavior in the two-phase transition between the Li-rich and Li-poor phases. Rietveld refinement shows that the discharge-charge asymmetry is caused by severe structural deformations in the Li-rich state. Furthermore, we find that deep discharge causes capacity fade. This appears to be linked to the structural deformation causing an irreversible decrease in the Li-ion diffusion coefficients, determined herein by galvanostatic intermittent titrations.

KW - Cyclic voltammetry

KW - Galvanostatic intermittent titration technique

KW - Li-ion batteries

KW - Operando synchrotron PXRD

KW - Phase transition

KW - Structural distortion

KW - VO(B)

UR - http://www.scopus.com/inward/record.url?scp=85143314255&partnerID=8YFLogxK

U2 - 10.1016/j.jpowsour.2022.232435

DO - 10.1016/j.jpowsour.2022.232435

M3 - Journal article

AN - SCOPUS:85143314255

SN - 0378-7753

VL - 556

JO - Journal of Power Sources

JF - Journal of Power Sources

M1 - 232435

ER -