Effect of pre-sintering processes and additions on densification in LLZO solid electrolytes

In this thesis, it is aimed to increase the density of the solid electrolyte material Li7La3Zr2O12 (LLZO), which has a high potential for use in solid state batteries, and to increase its ionic conductivity depending on the density increase. In this context, it was tried to get LLZO solid electrolyte with a dense microstructure by examining the effects of pre-sintering processes and additions on densification in LLZO solid electrolytes. LLZO solid electrolyte materials were produced by conventional solid-state reaction, which offers advantages such as simple preparation process, high yield and low cost. Microstructure investigations were carried out with scanning electron microscope in SE (Seconder electron) and BSE (Back scatter electron) modes. Phase analyzes were performed by XRD method. The ionic conductivity values were measured by the electrochemical impedance spectrum method and were calculated considering the geometrical factors. In this study, it was determined that the sample with suitable grain growth, dense structure and high ionic conductivity was the T-LLZO sample, which was calcined in powder form, sintered at 1100 ºC, powder bed was used during sintering and 10% RMD-LLZO added (5.6 x 10-4 S/cm).