关键词: Li₇La₃Zr₂O₁₂, 石榴石型, Ta ⁵⁺掺杂, 固相法

Abstract:

The tantalum ion (Ta ⁵⁺) doped garnet-type inorganic solid electrolyte Ta-LLZO was prepared by solid state reaction, and the effect of doping amount on the properties of the materials was investigated. The materials were characterized by X-ray diffraction (XRD), field emission electron scanning microscopy (FESEM) and electrochemical impedance spectroscopy (EIS). And the cycle stability was tested by assembly of LiFePO₄//LLZTO//Li all solid lithium battery. The results show that with the increase of Ta ⁵⁺ doping amount, the material appeared to form a single cubic phase structure. When the Ta ⁵⁺ doping content became 14.09wt.%, x=0.3, the room temperature ionic conductivity of the material reached the maximum (2.58×10 ^-4 S·cm ^-1), forming a stable cubic phase structure with a relatively high density (89.16%). In addition, the relatively stable cycle stability was obtained and the capacity retention rate remained at around 88.67% after 50 cycles.

Key words: Li₇La₃Zr₂O₁₂, Garnet-type, Ta ⁵⁺ doping, solid state reaction