Processing and Enhanced Electrochemical Properties of Li7La3Zr2−xTixO12 Solid Electrolyte by Chemical Co-precipitation

• Published in: Journal of electronic materials 2020-08, Vol.49 (8), p.4910-4915
• Main Authors: Wang, Tuo, Zhang, Xin, Yao, Zhongran, Li, Jun, Zhu, Kongjun, Wang, Jing, Yan, Kang
• Format: Article
• Language: English
• Subjects: Ceramics; Characterization and Evaluation of Materials; Chemical composition; Chemical precipitation; Chemical synthesis; Chemistry and Materials Science; Coprecipitation; Crystallization; Differential thermal analysis; Electrochemical analysis; Electrolytes; Electronics and Microelectronics; Grain boundaries; Grain size; Gravimetric analysis; Instrumentation; Ion currents; Lithium; Lithium-ion batteries; Low temperature; Materials Science; Morphology; Optical and Electronic Materials; Phase transitions; Precursors; Rechargeable batteries; Sintering (powder metallurgy); Solid electrolytes; Solid State Physics
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-020-08221-8

Garnet-like solid electrolyte ceramics, Li 7 La 3 Zr 2− x Ti x O 12 (LLZTO, x  = 0, 0.1, 0.2, and 0.3), were successfully synthesized at low temperature via chemical co-precipitation. The composition and phase transformation during the heating of the LLZTO precursors are analyzed using thermal gravimetric and differential thermal analysis and x-ray diffraction. The results indicated that 900°C was the likely activation point of LLZTO precursor powder crystallization and all the samples sintered at 1120°C formed a single phase with cubic garnet-like structure. The different morphologies of the LLZTO are characterized using scanning electron microscopy. As the content of Ti increased, the grain size increased to 20  μ m, and few pores are observed on the grain boundaries. Additionally, Ti doping increased the ionic conductivity of LLZO ceramics: the sample with x  = 0.1 reaches a maximum total ionic conductivity of 1.91 × 10 −4  S cm −1 at 298 K and its activation energy is 0.33 eV, which may be a significant step towards the goal of an ultimate safe solid electrolyte of a solid-state lithium ion battery.