Mechanochemical Synthesis and Characterization of Metastable Hexagonal Li4SnS4 Solid Electrolyte

Kento Kanazawa; So Yubuchi; Chie Hotehama; Misae Otoyama; Seiya Shimono; Hiroki Ishibashi; Yoshiki Kubota; Atsushi Sakuda; Akitoshi Hayashi; Masahiro Tatsumisago

doi:10.1021/acs.inorgchem.8b01049

Mechanochemical Synthesis and Characterization of Metastable Hexagonal Li₄SnS₄ Solid Electrolyte

Inorg Chem. 2018 Aug 20;57(16):9925-9930. doi: 10.1021/acs.inorgchem.8b01049. Epub 2018 Aug 9.

Affiliations

¹ Department of Applied Chemistry, Graduate School of Engineering , Osaka Prefecture University , 1-1 Gakuen-cho , Naka-ku, Sakai , Osaka 599-8531 , Japan.
² Department of Physical Science, Graduate School of Science , Osaka Prefecture University , 1-1 Gakuen-cho , Naka-ku, Sakai , Osaka 599-8531 , Japan.

PMID: 30091598
DOI: 10.1021/acs.inorgchem.8b01049

Abstract

A new crystalline lithium-ion conducting material, Li₄SnS₄ with an ortho-composition, was prepared by a mechanochemical technique and subsequent heat treatment. Synchrotron X-ray powder diffraction was used to analyze the crystal structure, revealing a space group of P6₃/ mmc and cell parameters of a = 4.01254(4) Å and c = 6.39076(8) Å. Analysis of a heat-treated hexagonal Li₄SnS₄ sample revealed that both lithium and tin occupied either of two adjacent tetrahedral sites, resulting in fractional occupation of the tetrahedral site (Li, 0.375; Sn, 0.125). The heat-treated hexagonal Li₄SnS₄ had an ionic conductivity of 1.1 × 10^-4 S cm^-1 at room temperature and a conduction activation energy of 32 kJ mol^-1. Moreover, the heat-treated Li₄SnS₄ exhibited a higher chemical stability in air than the Li₃PS₄ glass-ceramic.