Atomic-Resolution Electron Microscopy Unravelling the Role of Unusual Asymmetric Twin Boundaries in the Electron-Beam-Sensitive NASICON-Type Solid Electrolyte

Zhenqi Gu; Kai Wang; Yifei Rao; Pengfei Nan; Lixun Cheng; Binghui Ge; Wenhua Zhang; Cheng Ma

doi:10.1021/acs.nanolett.3c03852

Atomic-Resolution Electron Microscopy Unravelling the Role of Unusual Asymmetric Twin Boundaries in the Electron-Beam-Sensitive NASICON-Type Solid Electrolyte

Nano Lett. 2023 Dec 27;23(24):11818-11826. doi: 10.1021/acs.nanolett.3c03852. Epub 2023 Dec 11.

Authors

Zhenqi Gu^{1

2}, Kai Wang^{1

2

3}, Yifei Rao², Pengfei Nan⁴, Lixun Cheng⁴, Binghui Ge⁴, Wenhua Zhang^{1

2}, Cheng Ma^{1

2

5}

Affiliations

¹ Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
² CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China.
³ School of Materials & Energy, Lanzhou University, Lanzhou, Gansu 730000, China.
⁴ Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, China.
⁵ National Synchrotron Radiation Laboratory, Hefei, Anhui 230026, China.

PMID: 38078871
DOI: 10.1021/acs.nanolett.3c03852

Abstract

An atomic-scale understanding of the role of nonperiodic features is essential to the rational design of highly Li-ion-conductive solid electrolytes. Unfortunately, most solid electrolytes are easily damaged by the intense electron beam needed for atomic-resolution electron microscopy observation, so the reported in-depth atomic-scale studies are limited to Li_0.33La_0.56TiO₃- and Li₇La₃Zr₂O₁₂-based materials. Here, we observe on an atomic scale a third type of solid electrolyte, Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP), through minimization of damage induced by specimen preparation. With this capability, LATP is found to contain large amounts of twin boundaries with an unusual asymmetric atomic configuration. On the basis of the experimentally determined structure, the theoretical calculations suggest that such asymmetric twin boundaries may considerably promote Li-ion transport. This discovery identifies a new entry point for optimizing ionic conductivity, and the method presented here will also greatly benefit the mechanistic study of solid electrolytes.

Keywords: NASICON; electron-beam irradiation damage; nonperiodic features; scanning transmission electron microscopes; solid electrolytes.