Journalartikel

Jahr der Veröffentlichung: 2023

Seiten: 7147-7158

Zeitschrift: Journal of the American Chemical Society

Bandnummer: 145

Heftnummer: 13

ISSN: 0002-7863

eISSN: 1520-5126

DOI Link: https://doi.org/10.1021/jacs.2c11803

Verlag: American Chemical Society

Abstract: 
Aliovalent substitution is a common strategy to improve the ionic conductivity of solid electrolytes for solid-state batteries. The substitution of SbS43- by WS42- in Na2.9Sb0.9W0.1S4 leads to a very high ionic conductivity of 41 mS cm-1 at room temperature. While pristine Na3SbS4 crystallizes in a tetragonal structure, the substituted Na2.9Sb0.9W0.1S4 crystallizes in a cubic phase at room temperature based on its X-ray diffractogram. Here, we show by performing pair distribution function analyses and static single-pulse 121Sb NMR experiments that the short-range order of Na2.9Sb0.9W0.1S4 remains tetragonal despite the change in the Bragg diffraction pattern. Temperature-dependent Raman spectroscopy revealed that changed lattice dynamics due to the increased disorder in the Na+ substructure leads to dynamic sampling causing the discrepancy in local and average structure. While showing no differences in the local structure, compared to pristine Na3SbS4, quasi-elastic neutron scattering and solid-state 23Na nuclear magnetic resonance measurements revealed drastically improved Na+ diffusivity and decreased activation energies for Na2.9Sb0.9W0.1S4. The obtained diffusion coefficients are in very good agreement with theoretical values and long-range transport measured by impedance spectroscopy. This work demonstrates the importance of studying the local structure of ionic conductors to fully understand their transport mechanisms, a prerequisite for the development of faster ionic conductors.

Harvard-Zitierstil: Maus, O., Agne, M., Fuchs, T., Till, P., Wankmiller, B., Gerdes, J., et al. (2023) On the Discrepancy between Local and Average Structure in the Fast Na plus Ionic Conductor Na2.9Sb0.9W0.1S4, Journal of the American Chemical Society, 145(13), pp. 7147-7158. https://doi.org/10.1021/jacs.2c11803

APA-Zitierstil: Maus, O., Agne, M., Fuchs, T., Till, P., Wankmiller, B., Gerdes, J., Sharma, R., Heere, M., Jalarvo, N., Yaffe, O., Hansen, M., & Zeier, W. (2023). On the Discrepancy between Local and Average Structure in the Fast Na plus Ionic Conductor Na2.9Sb0.9W0.1S4. Journal of the American Chemical Society. 145(13), 7147-7158. https://doi.org/10.1021/jacs.2c11803