Poster De Conférence Année : 2024

Structure evolution of sodium thiophosphate electrolytes as function of the temperature

Résumé

Batteries play a crucial role in addressing global warming, yet their dependence on lithium-based compounds is critical due to worldwide Li resource depletion. Exploring the potential of sodium-based material is of utmost importance especially for next generation solid state batteries. Here, we focus on Na3PS4 (NPS) solid electrolyte. While the tetragonal α-NPS phase was initially studied for Na solid-state batteries,1 other amorphous and crystalline polymorphs obtained through mechanochemical and thermal synthesis methods are yet to be investigated.2,3 To date, the impact of heat treatment on these phases and their transitions remains poorly understood. We evaluated the structural evolution as function of the temperature of amorphous and semi-crystalline Na3PS4 polymorphs obtained by mechanochemical processes. The synchrotron X-ray diffraction (sXRD) diagrams of (a) am NPS and (b) sc NPS samples are displayed in Fig. 1a (RT). The sc NPS is refined by the Rietveld method from sXRD and neutrons powder diffraction (NPD) data in the cubic I-43m phase, and a Bond-Valence Energy Landscape reveals the Na+ conduction pathway (Fig. 1b). Both samples are then heat-treated in an in situ sXRD analysis, and multiple phase transitions are seen, some of them being irreversible (Fig. 1c,d). A novel orthorhombic phase is discovered (red curve) and its space group identified during the thermal treatment of am NPS sample. The ionic conductivity of both amorphous and semi-crystalline samples, initially in the order of 10–6 S/cm with activation energies ranging from 2.4 to 0.46 eV, undergo significant enhancement after a 12-hour heat treatment, reaching 0.12 and 0.16 S/cm, respectively. This research sheds light on the thermal dynamics of Na3PS4 polymorphs, providing valuable insights into their crystallization processes, especially in the amorphous-to-cubic transition. The discovered intermediate phase and improved ionic conductivities post-heat treatment underscore the potential for further advancements in sodium-based solid-state battery technologies.

Domaines

Matériaux
Fichier principal
Vignette du fichier
Poster-ISE2024.pdf (7.66 Mo) Télécharger le fichier
Origine Fichiers produits par l'(les) auteur(s)

Dates et versions

cea-04706851 , version 1 (23-09-2024)

Identifiants

  • HAL Id : cea-04706851 , version 1

Citer

Sergio Mayer, Marta Mirolo, Alisson A. Iles Velez, Ove Korjus, Emmanuelle Suard, et al.. Structure evolution of sodium thiophosphate electrolytes as function of the temperature. 75th Annual Meeting of the International Society of Electrochemistry, Aug 2024, Montreal, Canada. , 2024. ⟨cea-04706851⟩
43 Consultations
15 Téléchargements

Partager

More