The Impact of Lithium Variations on the Synthesis of LLZO Solid Electrolyte for Enhanced Lithium-Ion Battery Performance

The increasing demand for electronic devices and the high efficiency lithium-ion batteries (LIBs) have highlighted the need for safer alternatives to conventional liquid electrolytes, which pose risks such as fire and explosion. Solid electrolytes offer improved performance characteristics, including lower density, higher conductivity, and enhanced safety. This study focuses on the synthesis of Li۷La۳Zr۲O۱۲ (LLZO) solid electrolytes by varying the lithium content. Samples of LixLZO (x=۶, ۶.۵, ۷, ۷.۵, ۸) were synthesized by Sol-Gel method and calcination at ۹۰۰°C for ۶ hours followed by sintering at ۱۱۰۰°C for ۲۲ hours. The pellets were embedded in parent powder to prevent lithium loss during sintering. X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) analyses were conducted to investigate the formation LLZO and secondary phases and their impact on the final pellets. The results indicated that increasing lithium content initially enhanced the synthesis, but excessive lithium led to the formation of brittle and fragile phases, negatively affecting the electrolyte's performance.