Rapid Fabrication of of Li7La3Zr2O12 Solid Electrolyte with Enhanced Lithium Ionic Conductivity by Microwave Sintering

Traditional preparation method of solid electrolyte Li 7 La 3 Zr 2 O 12 requires a very long sintering holding time (> 36 hours). A efficient and mass production method, microwave sintering, is utilized to prepared LLZO by which the sintering time is reduced to be 2 ~ 4 h. Results show that cubic phase LLZO can be obtained at 1150 o C ~ 1200 o C. With the increase of holding time from 1 h to 4 h, tetragonal LLZO transforms to cubic which suggests extra thermal energy is generated by coupling dielectric loss with microwave. Pellet sintered with 4 h reaches the highest ionic conductivity of 3.1 x 10 -4 S cm -1 . Long holding time of 6 h will take away a lot of Li from the grain to form excess glass-like phase which is not favorable for conductivity.