Heavily Tungsten‐Doped Sodium Thioantimonate Solid‐State Electrolytes with Exceptionally Low Activation Energy for Ionic Diffusion. (8th November 2021)

• Record Type: Journal Article
• Authors: Feng, Xuyong; Fang, Hong; Liu, Pengcheng; Wu, Nan; Self, Ethan C.; Yin, Liang; Wang, Pengbo; Li, Xiang; Jena, Puru; Nanda, Jagjit; Mitlin, David
• Is Part Of: Angewandte Chemie. Volume 133:Number 50(2021)
• Page Start: 26362
• Page End: 26370
• Publication Date: 2021-11-08
• Subjects: Na3SbS4 -- sodium metal batteries -- sodium–sulfur batteries -- solid-state batteries -- superionic conductors; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202110699
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: A strategy for modifying the structure of solid‐state electrolytes (SSEs) to reduce the cation diffusion activation energy is presented. Two heavily W‐doped sodium thioantimonate SSEs, Na2.895 W0.3 Sb0.7 S4 and Na2.7 W0.3 Sb0.7 S4 are designed, both exhibiting exceptionally low activation energy and enhanced room temperature (RT) ionic conductivity; 0.09 eV, 24.2 mS/cm and 0.12 eV, 14.5 mS/cm. At −15 °C the Na2.895 W0.3 Sb0.7 S4 displays a total ionic conductivity of 5.5 mS/cm. The 30 % W content goes far beyond the 10–12 % reported in the prior studies, and results in novel pseudo‐cubic or orthorhombic structures. Calculations reveal that these properties result from a combination of multiple diffusion mechanisms, including vacancy defects, strongly correlated modes and excessive Na‐ions. An all‐solid‐state battery (ASSB) using Na2.895 W0.3 Sb0.7 S4 as the primary SSE and a sodium sulfide (Na2 S) cathode achieves a reversible capacity of 400 mAh g −1 . Abstract : A multi‐mechanistic strategy for tailoring the composition of solid‐state electrolytes (SSEs) to reduce the cation diffusion activation energy is presented. Two heavily W‐doped sodium thioantimonate SSEs, Na2.895 W0.3 Sb0.7 S4 and Na2.7 W0.3 Sb0.7 S4 are designed. Both exhibit exceptionally low activation energies and enhanced room‐temperature (RT) ionic conductivities; 0.09 eV, 24.2 mS/cm and 0.12 eV, 14.5 mS/cm, respectively.