In-situ synthesis of nanostructures on powder surfaces and low-temperature densification of LiLaZrO-based solid electrolytes

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15365
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 36010:Inorganic compounds and inorganic materials chemistry-related
• Research Institution: Nagoya Institute of Technology
• Principal Investigator: Fuchigami Teruaki 名古屋工業大学, 工学(系)研究科(研究院), 助教 (20756704)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: ナノ粒子 / 焼結 / 酸化物固体電解質 / 全固体電池 / セラミックス / 低温緻密化

Outline of Final Research Achievements

In this study, nanosized Li7La3Zr2O12-based solid electrolytes were synthesized for low-temperature densification of oxide solid electrolytes and investigated the sintering behavior of the nanoparticles alone and between nanoparticles and micro particles. 54 nm of Li6.4La3Zr1.4Ta0.6O12 particles (partially La2Zr2O7) and 64 nm of pure Li6.4La3Zr1.4Ta0.6O12 particles were successfully synthesized by planetary ball milling, and they were easy to be sintered even at a sintering temperature of 1000°C. Furthermore, formation of a good interface between nanoparticles and micro-particles was obtained at 1000°C by mixing the nanoparticles and microparticles, resulting in low grain boundary resistance and high ionic conductivity (3.4-3.8×10-4 S/cm). Relatively high relative densities were obtained by optimizing the mixing ratio of nanoparticles and microparticles, indicating that the addition of nanoparticles is effective for the low-temperature densification.

Free Research Field

無機材料化学

Academic Significance and Societal Importance of the Research Achievements

ナノ粒子は焼結性の向上に有効であることは以前から知られていたが、本研究では通常の焼結に用いるマイクロサイズの粉体と、ナノ粒子を混合することで、ナノ粒子単体よりも界面形成や低温緻密化に有効であることを示した。これは酸化物固体電解質に限らず、セラミックス全般の焼結に対して有効であると考えられる。また、ナノ粒子添加によるセラミックスの低温焼結技術は、製造時のエネルギーやCO2発生量の削減に対して有用である。