Phase Transition of Na3SbS4 Superionic Conductor and Its Impact on Ion Transport

TL;DR

This study investigates the phase transition of Na3SbS4, synthesizes its high-temperature cubic phase, and demonstrates that this phase exhibits enhanced ionic conductivity, which is promising for solid-state electrolyte applications.

Contribution

It combines experimental synthesis, structural verification, and computational analysis to reveal the phase transition and improved ion transport in Na3SbS4.

Findings

Cubic Na3SbS4 has higher ionic conductivity than tetragonal phase.

Both phases enable fast ion transport.

The phase transition impacts ion transport properties.

Abstract

In this work, a comprehensive research coupling experiment and computation has been performed to understand the phase transition of Na3SbS4 and to synthesize cubic Na3SbS4 (c-Na3SbS4), a high temperature phase of Na3SbS4 that is difficult to be preserved from high temperature. The formation of c-Na3SbS4 is verified by Rietveld refinement and electrochemical impedance spectroscopy. Both experiment and theoretical calculation reveal that the ionic conductivity of c-Na3SbS4 is higher than that of t-Na3SbS4, though the values are in the same order of magnitude. Both structures allow fast ion transport.