Mechanochemically Prepared Li2S-P2S5-LiBH4 Solid Electrolytes with an Argyrodite Structure

Atsushi Sakuda; Akihiro Yamauchi; So Yubuchi; Naoto Kitamura; Yasushi Idemoto; Akitoshi Hayashi; Masahiro Tatsumisago

doi:10.1021/acsomega.8b00377

Mechanochemically Prepared Li₂S-P₂S₅-LiBH₄ Solid Electrolytes with an Argyrodite Structure

ACS Omega. 2018 May 21;3(5):5453-5458. doi: 10.1021/acsomega.8b00377. eCollection 2018 May 31.

Authors

Atsushi Sakuda¹, Akihiro Yamauchi¹, So Yubuchi¹, Naoto Kitamura², Yasushi Idemoto², Akitoshi Hayashi¹, Masahiro Tatsumisago¹

Affiliations

¹ Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Osaka 599-8531, Japan.
² Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.

Abstract

Solid electrolytes with compositions of (100 - x)(0.75Li₂S·0.25P₂S₅)·xLiBH₄ (mol %, 0 ≤ x ≤ 100) were mechanochemically prepared from the 75Li₂S·25P₂S₅ (mol %) glass and LiBH₄ crystal. The samples with x ≥ 43 have crystalline phases and those with x ≤ 33 formed a glassy phase. The crystalline phase was identified as argyrodite Li₆PS₅(BH₄). The x = 50 sample formed a crystalline phase and demonstrated a high lithium-ion conductivity of 1.8 × 10^-3 S cm^-1 at 25 °C with an activation energy of 16 kJ·mol^-1. The argyrodite-type crystal with a BH₄ ^- anion that occupies the halide site is a novel and promising solid electrolyte.