Preparation of cubic Li7La3Zr2O12 solid electrolyte using a nano-sized core-shell structured precursor

摘要

Nano-sized Al-doped Li7La3Zr2O12 (LLZO) precursor is successfully synthesized by a novel two-step precipitation method. Microstructure and thermal behavior of the prepared LLZO precursor powders and properties of the sintered LLZO pellets are comprehensively investigated. Results show that the obtained precursor powders have a special core-shell structure that a coating of Li2C2O4 covers on the surface of the lanthanum and zirconium co-precipitate products. Pure cubic LLZO powders can be obtained at a low calcination temperature of 900 degrees C. Sample sintered by field assisted sintering technology at 1000 degrees C has a high relative density of 96.5% with a total ionic conductivity of as high as 3.32 x 10(-4) S cm(-1) (corresponding to the activation energy of 0.32 eV) at room temperature. The reported method provides a simple and low-temperature synthesis of high quality LLZO solid electrolytes.

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