Insights into the Rich Polymorphism of the Na+Ion Conductor Na3PS4from the Perspective of Variable-Temperature Diffraction and Spectroscopy

Theodosios Famprikis, Houssny Bouyanfif, Pieremanuele Canepa, Mohamed Zbiri, James A. Dawson, Emmanuelle Suard, François Fauth, Helen Y. Playford, Damien Dambournet, Olaf J. Borkiewicz, Matthieu Courty, Oliver Clemens, Jean Noël Chotard, M. Saiful Islam, Christian Masquelier

Research output: Contribution to journalArticlepeer-review

Abstract

Solid electrolytes are crucial for next-generation solid-state batteries, and Na3PS4 is one of the most promising Na+ conductors for such applications, despite outstanding questions regarding its structural polymorphs. In this contribution, we present a detailed investigation of the evolution in structure and dynamics of Na3PS4 over a wide temperature range 30 < T < 600 °C through combined experimental-computational analysis. Although Bragg diffraction experiments indicate a second-order phase transition from the tetragonal ground state (α, P4¯ 21c) to the cubic polymorph (β, I4¯ 3m) above ∼250 °C, pair distribution function analysis in real space and Raman spectroscopy indicate remnants of a tetragonal character in the range 250 < T < 500 °C, which we attribute to dynamic local tetragonal distortions. The first-order phase transition to the mesophasic high-temperature polymorph (γ, Fddd) is associated with a sharp volume increase and the onset of liquid-like dynamics for sodium-cations (translational) and thiophosphate-polyanions (rotational) evident by inelastic neutron and Raman spectroscopies, as well as pair-distribution function and molecular dynamics analyses. These results shed light on the rich polymorphism of Na3PS4 and are relevant for a range host of high-performance materials deriving from the Na3PS4 structural archetype.

Original languageEnglish
Pages (from-to) 5652–5667
JournalChemistry of Materials
Volume33
Issue number14
Early online date16 Jul 2021
DOIs
Publication statusPublished - 27 Jul 2021

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

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