Microstructure Manipulation for Enhancing the Resistance of Garnet-Type Solid Electrolytes to “Short Circuit” by Li Metal Anodes

• Published in: ACS applied materials & interfaces 2019-02, Vol.11 (6), p.5928-5937
• Main Authors: Ren, Yaoyu, Shen, Yang, Lin, Yuanhua, Nan, Ce-Wen
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.8b17954

Al-contained Li7–x La3Zr2– x Ta x O12 (xTa-LLZO) powder was synthesized via solid-state reaction, where increasing the Ta doping level was found to reduce the average particle size and facilitate a higher relative density in the sintered pellet. 0.8Ta-LLZO pellets sintered at 1150 °C achieved a relative density of 96.2 ± 0.2% and survived the Li striping/plating test under a unidirectional current polarization of 0.5 mA/cm2 for more than 8 h without short-circuiting. In contrast, other xTa-LLZO sintered pellets with lower Ta doping levels were short-circuited by lithium dendrites after polarization for much shorter time periods. The microstructure of the sintered body played a more essential role in lithium dendrite prevention compared to relative density alone. By characterizing the microstructure of xTa-LLZO sintered pellets, we proposed a formation mechanism of the pathways for lithium dendrite growth.