能源化学(英文版)

能源化学(英文版) ›› 2019, Vol. 39 ›› Issue (12): 8-16.

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Preparation of dense Ta-LLZO/MgO composite Li-ion solid electrolyte: Sintering, microstructure, performance and the role of MgO

Xiao Huanga,d, Yang Lua,d, Zhen Songb, Tongping Xiuc, Michael E. Baddingb, Zhaoyin Wena,d   

  1. a CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050, China;
    b Corning Incorporated, Corning, NY 14831, USA;
    c Corning Research Center China, 200 Jinsu Road, Shanghai 201206, China;
    d University of Chinese Academy of Sciences, 19 A Yuquan Rd, Shijingshan District, Beijing 100049, China
  • 收稿日期:2018-09-24 修回日期:2018-12-31 出版日期:2019-12-15 发布日期:2020-12-18
  • 通讯作者: Zhaoyin Wen, zywen@mail.sic.ac.cn
  • 基金资助:
    This work was financially supported by the National Key R&D Program of China under Grant No. 2018YFB0905400, Corning Incorporated, the National Natural Science Foundation of China under Grant No. 51772315, No. 51432010.

Preparation of dense Ta-LLZO/MgO composite Li-ion solid electrolyte: Sintering, microstructure, performance and the role of MgO

Xiao Huanga,d, Yang Lua,d, Zhen Songb, Tongping Xiuc, Michael E. Baddingb, Zhaoyin Wena,d   

  1. a CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050, China;
    b Corning Incorporated, Corning, NY 14831, USA;
    c Corning Research Center China, 200 Jinsu Road, Shanghai 201206, China;
    d University of Chinese Academy of Sciences, 19 A Yuquan Rd, Shijingshan District, Beijing 100049, China
  • Received:2018-09-24 Revised:2018-12-31 Online:2019-12-15 Published:2020-12-18
  • Contact: Zhaoyin Wen, zywen@mail.sic.ac.cn
  • Supported by:
    This work was financially supported by the National Key R&D Program of China under Grant No. 2018YFB0905400, Corning Incorporated, the National Natural Science Foundation of China under Grant No. 51772315, No. 51432010.

摘要： Cubic phase Li7La3Zr2O12 (LLZO), a member of the Li-Garnet family, is a promising solid electrolyte and has been widely studied in recent years. However, LLZO samples prepared via conventional ambient air sintering reported in the published literature often contain large grains with lower than desired (<94%) relative density. In this study, a non-contact method of co-firing with mother powder method is proposed to prepare high-quality Ta-doped LLZO-MgO composite ceramics. By sintering at 1150℃ for 5 h, the ceramics can reach relative density of 98.2%, conductivity of 5.17×10-4 S cm-1 at 25℃ and fracture strength of ～150 MPa. The sintered samples have uniform fine-grained microstructure and high critical current densities of 0.75-0.95 mA cm-2 at room temperature in Li-Li symmetry cell with Au modification. In addition, systematic sintering experiments and characterizations are conducted to explore the function of MgO in inhibiting the Ta-LLZO grain growth and its existing form inside the composite ceramics.

关键词: Li-Garnet, Solid electrolyte, Mechanism, Critical current density, Sintering

Abstract: Cubic phase Li7La3Zr2O12 (LLZO), a member of the Li-Garnet family, is a promising solid electrolyte and has been widely studied in recent years. However, LLZO samples prepared via conventional ambient air sintering reported in the published literature often contain large grains with lower than desired (<94%) relative density. In this study, a non-contact method of co-firing with mother powder method is proposed to prepare high-quality Ta-doped LLZO-MgO composite ceramics. By sintering at 1150℃ for 5 h, the ceramics can reach relative density of 98.2%, conductivity of 5.17×10-4 S cm-1 at 25℃ and fracture strength of ～150 MPa. The sintered samples have uniform fine-grained microstructure and high critical current densities of 0.75-0.95 mA cm-2 at room temperature in Li-Li symmetry cell with Au modification. In addition, systematic sintering experiments and characterizations are conducted to explore the function of MgO in inhibiting the Ta-LLZO grain growth and its existing form inside the composite ceramics.

Key words: Li-Garnet, Solid electrolyte, Mechanism, Critical current density, Sintering