Atomically Intimate Solid Electrolyte/Electrode Contact Capable of Surviving Long-Term Cycling with Repeated Phase Transitions

Feng Zhu; Zhenqi Gu; Fuzhen Li; Kai Wang; Jun Luo; Si Gao; Yuzhang Feng; Chunchen Zhang; Peng Wang; Yunzhe Zheng; Wangqiong Xu; Rong Huang; Yingying Lu; Cheng Ma

doi:10.1021/acs.nanolett.2c00885

Atomically Intimate Solid Electrolyte/Electrode Contact Capable of Surviving Long-Term Cycling with Repeated Phase Transitions

Nano Lett. 2022 Apr 27;22(8):3457-3464. doi: 10.1021/acs.nanolett.2c00885. Epub 2022 Apr 18.

Authors

Feng Zhu¹, Zhenqi Gu¹, Fuzhen Li¹, Kai Wang¹, Jun Luo^{2

3}, Si Gao⁴, Yuzhang Feng⁴, Chunchen Zhang⁴, Peng Wang^{4

5}, Yunzhe Zheng⁶, Wangqiong Xu⁶, Rong Huang⁶, Yingying Lu⁷, Cheng Ma^{1

8}

Affiliations

¹ Hefei National Research Center for Physical Sciences at the Microscale, 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.
² Shenzhen Institute for Advanced Study, University of Electronic Science and Technology of China, Shenzhen, Guangdong 518110, China.
³ School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China.
⁴ National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, Jiangsu 210093, China.
⁵ Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom.
⁶ Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200062, China.
⁷ College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, China.
⁸ National Synchrotron Radiation Laboratory, Hefei, Anhui 230026, China.

PMID: 35435693
DOI: 10.1021/acs.nanolett.2c00885

Abstract

The electrode-electrolyte contact issue within the composite electrode layer is a grand challenge for all-solid-state Li batteries. In order to achieve cycling performances comparable to Li-ion batteries based on liquid electrolyte, the aforementioned solid-solid contact not only needs to be sufficiently thorough but also must tolerate repeated cycling. Simultaneously meeting both requirements is rather challenging. Here, we discover that epitaxy may effectively overcome such bottlenecks even when the electrode undergoes repeated phase transitions during cycling. Through epitaxial growth, the perovskite Li_0.33La_0.56TiO₃ solid electrolyte was found capable of forming atomically intimate contact with both the spinel Li₄Ti₅O₁₂ and rock-salt Li₇Ti₅O₁₂. In contrast to conventional expectations, such epitaxial interfaces can also survive repeated spinel-to-rock-salt phase transitions. Consequently, the Li₄Ti₅O₁₂-Li_0.33La_0.56TiO₃ composite electrode based on epitaxial solid-solid contact delivers not only a rate capability comparable to that of the surry-cast one with solid-liquid contact but also an excellent long-term cycling stability.

Keywords: electron microscopy; epitaxy; interface; solid electrolytes; solid−solid composite electrodes.