• Corpus ID: 247922614

Atomic-scale origin of the low grain-boundary resistance in perovskite solid electrolytes

@inproceedings{Lee2022AtomicscaleOO,
  title={Atomic-scale origin of the low grain-boundary resistance in perovskite solid electrolytes},
  author={Tom Lee and Ji Qi and Chaitanya A Gadre and Huaixun Huyan and Shu-Ting Ko and Yunxing Zuo and Chaojie Du and Jie Li and Toshihiro Aoki and Caden John Stippich and Ruqian Wu and Jian Luo and Shyue Ping Ong and Xiaoqing Pan},
  year={2022}
}

• Tom Lee, Ji Qi, +11 authors Xiaoqing Pan
• Published 31 March 2022
• Materials Science

word count: 195. Main body of the text word count: 4780. Number of references: 56. Number of figures in main text: 5. Number of tables in main text: 0. Number of figures in supporting information: 16. Number of tables in supporting information: 4. Abstract Oxide solid electrolytes (OSEs) have the potential to achieve improved safety and energy density for lithium-ion batteries, but their high grain-boundary (GB) resistance is a general bottleneck. In the most well studied perovskite OSE, Li 3 x La 2/3- x TiO 3 (LLTO), the ionic conductivity of GBs is about three orders of magnitude lower than that of the bulk. In contrast, the related Li 0.375 Sr 0.4375 Ta 0.75 Zr 0.25 O 3 (LSTZ0.75) perovskite exhibits low GB resistance for reasons yet unknown. Here, we used aberration-corrected scanning transmission electron microscopy and spectroscopy, along with an active learning moment tensor potential, to reveal the atomic scale structure and composition of LSTZ0.75 GBs. Vibrational electron energy loss spectroscopy is applied for the first time to characterize the otherwise unmeasurable Li distribution in GBs of LSTZ0.75. We found that Li depletion, which is a major reason for the low GB ionic conductivity of LLTO, is absent for the GBs of LSTZ0.75. Instead, the low GB resistivity of LSTZ0.75 is attributed to the formation of a unique defective cubic perovskite interfacial structure that contained abundant vacancies. Our study provides insights into the atomic scale mechanisms of low GB resistivity and sheds light on possible paths for designing OSEs with high total ionic conductivity.