Revealing Structural Insights of Solid Electrolyte Interphase in High-Concentrated Non-Flammable Electrolyte for Li Metal Batteries by Cryo-TEM

Qing Zhang; Chuan Zhou; Menghao Li; Yuanmin Zhu; Xianbin Wei; Shaocheng Shen; Zongwei Ji; Guangfu Luo; Yifeng Cheng; Xuming Yang; Zhijie Wang; Lingfeng Zou; Lin Zeng; Junhao Lin; Lei Li; Joseph S Francisco; Meng Gu

doi:10.1002/smll.202300849

Revealing Structural Insights of Solid Electrolyte Interphase in High-Concentrated Non-Flammable Electrolyte for Li Metal Batteries by Cryo-TEM

Small. 2023 Jul;19(28):e2300849. doi: 10.1002/smll.202300849. Epub 2023 Mar 29.

Authors

Qing Zhang^{1

2}, Chuan Zhou¹, Menghao Li¹, Yuanmin Zhu^{1

3}, Xianbin Wei¹, Shaocheng Shen⁴, Zongwei Ji¹, Guangfu Luo^{1

5}, Yifeng Cheng¹, Xuming Yang¹, Zhijie Wang⁶, Lingfeng Zou², Lin Zeng², Junhao Lin¹, Lei Li¹, Joseph S Francisco⁷, Meng Gu¹

Affiliations

¹ Department of Materials Science and Engineering, Southern University of Science and Technology (SUSTech), Shenzhen, 518055, P. R. China.
² Department of Mechanical and Energy Engineering, Southern University of Science and Technology (SUSTech), Shenzhen, 518055, P. R. China.
³ School of Materials Science and Engineering, Dongguan University of Technology, Dongguan, 523808, P. R. China.
⁴ Department of Chemistry, Mississippi State University, 75 B. S. Hood Rd, Mississippi State, MS, 39762, USA.
⁵ Guangdong Provincial Key Laboratory of Computational Science and Material Design, Southern University of Science and Technology, Shenzhen, 518055, P. R. China.
⁶ Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, 999077, P. R. China.
⁷ Department of Earth and Environmental, Sciences and Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA.

PMID: 36988005
DOI: 10.1002/smll.202300849

Abstract

High-concentrated non-flammable electrolytes (HCNFE) in lithium metal batteries prevent thermal runaway accidents, but the microstructure of their solid electrolyte interphase (SEI) remains largely unexplored, due to the lack of direct imaging tools. Herein, cryo-HRTEM is applied to directly visualize the native state of SEI at the atomic scale. In HCNFE, SEI has a uniform laminated crystalline-amorphous structure that can prevent further reaction between the electrolyte and lithium. The inorganic SEI component, Li₂ S₂ O₇ , is precisely identified by cryo-HRTEM. Density functional theory (DFT) calculations demonstrate that the final Li₂ S₂ O₇ phase has suitable natural transmission channels for Li-ion diffusion and excellent ionic conductivity of 1.2 × 10^-5 S cm^-1 .

Keywords: Cryo-TEM; Li metal batteries; high concentration non-flammable electrolytes; solid electrolyte interphase (SEI) configuration.

Abstract

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