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Time and space resolved operando synchrotron X-ray and Neutron diffraction study of NMC811/Si–Gr 5 Ah pouch cells

Graae, Kristoffer Visti ; Li, Xinyu ; Sørensen, Daniel Risskov LU orcid ; Ayerbe, Elixabete ; Boyano, Iker ; Sheptyakov, Denis ; Jørgensen, Mads Ry Vogel LU orcid and Norby, Poul (2023) In Journal of Power Sources 570.
Abstract

Silicon–Graphite blended electrodes in Li-ion batteries have been proposed as a way to harness the high capacity of Si as an anode material, while minimising the negative effects of their large volume expansion. NMC 811 is the current state-of-the-art layered oxide cathode material, where the cobalt content of the cathode has been minimised. These are the two of the most promising materials for achieving electric vehicle targets in terms of performance, cyclability and price, however their degradation mechanism is not fully understood. Here these two materials have been used to manufacture 5 Ah prototype multi-layer pouch cells, which are aged and then studied using two complimentary diffraction techniques. Neutron diffraction has... (More)

Silicon–Graphite blended electrodes in Li-ion batteries have been proposed as a way to harness the high capacity of Si as an anode material, while minimising the negative effects of their large volume expansion. NMC 811 is the current state-of-the-art layered oxide cathode material, where the cobalt content of the cathode has been minimised. These are the two of the most promising materials for achieving electric vehicle targets in terms of performance, cyclability and price, however their degradation mechanism is not fully understood. Here these two materials have been used to manufacture 5 Ah prototype multi-layer pouch cells, which are aged and then studied using two complimentary diffraction techniques. Neutron diffraction has enabled a quantitative analysis of phase transitions in Si–Gr anodes in a pristine and degraded cell, and the alloying behaviour of Si and Li has been inferred by comparison of identical cells with either graphite or Si–Gr anodes. Synchrotron X-ray Diffraction has been used to make an operando 2D map of the cathode and anode lithiation in the pouch cell, as well as to map the volume expansion across the cell. This approach has revealed that degradation entails significant inhomogeneities across both electrodes, linked to the inhomogeneous volume expansion of the Si–Gr anodes.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
In situ, Neutron diffraction, NMC 811, Pouch cell, Silicon–graphite, XRD
in
Journal of Power Sources
volume
570
article number
232993
publisher
Elsevier
external identifiers
  • scopus:85152123353
ISSN
0378-7753
DOI
10.1016/j.jpowsour.2023.232993
language
English
LU publication?
yes
id
212cbd19-f25a-4d80-997d-623bb4d26c48
date added to LUP
2023-06-12 15:03:14
date last changed
2023-06-12 15:03:14
@article{212cbd19-f25a-4d80-997d-623bb4d26c48,
  abstract     = {{<p>Silicon–Graphite blended electrodes in Li-ion batteries have been proposed as a way to harness the high capacity of Si as an anode material, while minimising the negative effects of their large volume expansion. NMC 811 is the current state-of-the-art layered oxide cathode material, where the cobalt content of the cathode has been minimised. These are the two of the most promising materials for achieving electric vehicle targets in terms of performance, cyclability and price, however their degradation mechanism is not fully understood. Here these two materials have been used to manufacture 5 Ah prototype multi-layer pouch cells, which are aged and then studied using two complimentary diffraction techniques. Neutron diffraction has enabled a quantitative analysis of phase transitions in Si–Gr anodes in a pristine and degraded cell, and the alloying behaviour of Si and Li has been inferred by comparison of identical cells with either graphite or Si–Gr anodes. Synchrotron X-ray Diffraction has been used to make an operando 2D map of the cathode and anode lithiation in the pouch cell, as well as to map the volume expansion across the cell. This approach has revealed that degradation entails significant inhomogeneities across both electrodes, linked to the inhomogeneous volume expansion of the Si–Gr anodes.</p>}},
  author       = {{Graae, Kristoffer Visti and Li, Xinyu and Sørensen, Daniel Risskov and Ayerbe, Elixabete and Boyano, Iker and Sheptyakov, Denis and Jørgensen, Mads Ry Vogel and Norby, Poul}},
  issn         = {{0378-7753}},
  keywords     = {{In situ; Neutron diffraction; NMC 811; Pouch cell; Silicon–graphite; XRD}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Journal of Power Sources}},
  title        = {{Time and space resolved operando synchrotron X-ray and Neutron diffraction study of NMC811/Si–Gr 5 Ah pouch cells}},
  url          = {{http://dx.doi.org/10.1016/j.jpowsour.2023.232993}},
  doi          = {{10.1016/j.jpowsour.2023.232993}},
  volume       = {{570}},
  year         = {{2023}},
}