Effect of grain boundary resistance on the ionic conductivity of amorphous x Li2S-(100- x)LiI binary system

Longbang Di; Jiangyang Pan; Lei Gao; Jinlong Zhu; Liping Wang; Xiaomeng Wang; Qinqin Su; Song Gao; Ruqiang Zou; Yusheng Zhao; Songbai Han

doi:10.3389/fchem.2023.1230187

Effect of grain boundary resistance on the ionic conductivity of amorphous x Li₂S-(100- x)LiI binary system

Front Chem. 2023 Jul 20:11:1230187. doi: 10.3389/fchem.2023.1230187. eCollection 2023.

Authors

Affiliations

¹ Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, China.
² School of Materials Science and Engineering, Peking University, Beijing, China.
³ Eastern Institute for Advanced Study, Ningbo, China.

Abstract

Solid-state electrolytes (SSEs) hold the key position in the progress of cutting-edge all-solid-state batteries (ASSBs). The ionic conductivity of solid-state electrolytes is linked to the presence of both amorphous and crystalline phases. This study employs the synthesis method of mechanochemical milling on binary xLi₂S-(100-x)LiI system to investigate the effect of amorphization on its ionic conductivity. Powder X-ray diffraction (PXRD) shows that the stoichiometry of Li₂S and LiI has a significant impact on the amorphization of xLi₂S-(100-x)LiI system. Furthermore, the analysis of electrochemical impedance spectroscopy (EIS) indicates that the amorphization of xLi₂S-(100-x)LiI system is strongly correlated with its ionic conductivity, which is primarily attributed to the effect of grain boundary resistance. These findings uncover the latent connections between amorphization, grain boundary resistance, and ionic conductivity, offering insight into the design of innovative amorphous SSEs.

Keywords: amorphous; grain boundary resistance; ionic conductivity; mechanochemical milling; solid-state electrolytes.