Exploring the Underlying Correlation between the Structure and Ionic Conductivity in Halide Spinel Solid-State Electrolytes with Neutron Diffraction

Jiangyang Pan; Lei Gao; Xinyu Zhang; Dubin Huang; Jinlong Zhu; Liping Wang; Yadong Wei; Wen Yin; Yuanguang Xia; Ruqiang Zou; Yusheng Zhao; Songbai Han

doi:10.1021/acs.inorgchem.3c04094

Exploring the Underlying Correlation between the Structure and Ionic Conductivity in Halide Spinel Solid-State Electrolytes with Neutron Diffraction

Inorg Chem. 2024 Feb 19;63(7):3418-3427. doi: 10.1021/acs.inorgchem.3c04094. Epub 2024 Feb 7.

Authors

Jiangyang Pan^{1

2}, Lei Gao³, Xinyu Zhang², Dubin Huang³, Jinlong Zhu², Liping Wang¹, Yadong Wei⁴, Wen Yin^{5

6}, Yuanguang Xia^{5

6}, Ruqiang Zou³, Yusheng Zhao⁷, Songbai Han¹

Affiliations

¹ Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen 518055, China.
² Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China.
³ School of Materials Science and Engineering, Peking University, Beijing 100871, China.
⁴ Institute of Science & Technology Innovation, Dongguan University of Technology (Institute of Science & Technology Innovation and Advanced Manufacturing), Dongguan 523000, China.
⁵ Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
⁶ Spallation Neutron Source Science Center, Dongguan 523803, China.
⁷ Eastern Institute for Advanced Study, Ningbo 315201, China.

PMID: 38323573
DOI: 10.1021/acs.inorgchem.3c04094

Abstract

The development of cutting-edge solid-state electrolytes (SSEs) entails a deep understanding of the underlying correlation between the structure and ionic conductivity. Generally, the structure of SSEs encompasses several interconnected crystal parameters, and their collective influence on Li⁺ transport can be challenging to discern. Here, we systematically investigate the structure-function relationship of halide spinel Li_xMgCl_2+x (2 ≥ x ≥ 1) SSEs. A nonmonotonic trend in the ionic conductivity of Li_xMgCl_2+x SSEs has been observed, with the maximum value of 8.69 × 10^-6 S cm^-1 achieved at x = 1.4. The Rietveld refinement analysis, based on neutron diffraction data, has revealed that the crystal parameters including cell parameters, Li⁺ vacancies, Debye-Waller factor, and Li-Cl bond length assume diverse roles in influencing ionic conductivity of Li_xMgCl_2+x at different stages within the range of x values. Besides, mechanistic analysis demonstrates Li⁺ transport along three-dimensional pathways, which primarily governs the contribution to ionic conductivity of Li_xMgCl_2+x SSEs. This study has shed light on the collective influence of crystal parameters on Li⁺ transport behaviors, providing valuable insights into the intricate relationship between the structure and ionic conductivity of SSEs.