Cristin-resultat-ID: 2026224
Sist endret: 24. januar 2023, 14:27
Resultat
Vitenskapelig foredrag
2022

Tracing the (de)sodiation of Bi2MoO6 through good and bad times with operando XRD

Bidragsytere:
  • Anders Brennhagen
  • Carmen Cavallo
  • David Stephen Wragg
  • Vajeeston Ponniah
  • Anja Olafsen Sjåstad
  • Alexey Koposov
  • mfl.

Presentasjon

Navn på arrangementet: International Operando Battery Days
Sted: Grenoble
Dato fra: 16. mai 2022
Dato til: 18. mai 2022

Arrangør:

Arrangørnavn: CNRS, CEA

Om resultatet

Vitenskapelig foredrag
Publiseringsår: 2022

Klassifisering

Vitenskapsdisipliner

Uorganisk kjemi

Emneord

Operando • Na-ionebatteri • Røntgendiffraksjon

Beskrivelse Beskrivelse

Tittel

Tracing the (de)sodiation of Bi2MoO6 through good and bad times with operando XRD

Sammendrag

Anode materials combining conversion and alloying mechanisms (CAMs) are promising for Na-ion batteries, but their complex cycling mechanisms are challenging to study1. Understanding the (de)sodiation mechanism is crucial and, in several cases, requires advanced synchrotron characterization. Operando synchrotron studies are generally limited to one or two sodiation cycles, which are not fully comprehensive for CAMs2. Therefore, herein, we studied the sodiation and desodiation of Bi2MoO6-based anodes with laboratory-based operando X-ray diffraction exceeding more than 30 cycles to have a complete overview of our CAM’s mechanism (Figure 1)3. This revealed important aspects of the cycling and degradation mechanisms in the material. During the first sodiation, an irreversible conversion of Bi2MoO6 occurs, creating Bi nanoparticles embedded in an amorphous Na-Mo-O matrix. The Bi particles then reversibly alloy with Na forming cubic Na3Bi leading to a specific capacity close to 300 mAh g−1 for the 10 first cycles. This is followed by a rapid capacity decay where the sodiation of Bi becomes irreversible leaving several inactive Na3Bi particles. To the best of our knowledge, this is due to the observed crystal growth of the Bi particles accompanied by structural changes in the insulating Na-Mo-O leading to poor conductivity in the electrodes. The poor electronic conductivity of the matrix deactivates the NaxBi particles and prevents the formation of the solid electrolyte interface layer as shown by post-mortem scanning electron microscopy studies.

Bidragsytere

Anders Brennhagen

  • Tilknyttet:
    Forfatter
    ved Senter for Materialvitenskap og Nanoteknologi kjemi ved Universitetet i Oslo
Inaktiv cristin-person

Carmen Cavallo

  • Tilknyttet:
    Forfatter

David Stephen Wragg

  • Tilknyttet:
    Forfatter
Aktiv cristin-person

Vajeeston Ponniah

  • Tilknyttet:
    Forfatter

Anja Olafsen Sjåstad

  • Tilknyttet:
    Forfatter
    ved Kjemisk institutt ved Universitetet i Oslo
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