Katı-hal lityum-iyon pillerin üretimi ve karakterizasyonu

Garnet type Li7La3Zr2O12 (LLZO) solid electrolytes are considered as a potential candidate for replacing traditional organic electrolytes. However, their performance is not yet approaching organic-based liquid electrolytes. The studies on the performance enhancement have focused more on crystal chemistry and lithium kinetics, but not enough studies were carried out to elucidate sintering behavior. The dissertation covers LLZO synthesis conditions in terms of Al content, heating rate and precursor type. Then, a potential sintering mechanism related to sintering temperature is introduced. Li detection in electron microscopy techniques and air stability of the LLZO samples are discussed by using ToF-SIMS attached FIB-SEM. In the Citrate-Nitrate LLZO synthesis, the effect of Zirconium source and anionic species on the cubic phase stabilization of LLZO is covered. The thermodynamically favored precursors are also determined and the impurities in the structure have been successfully determined with the use of high-sensitivity Lithium maps in LLZO by using ToF-SIMS attached to Xe ion-source FIB-SEM. In Citrate-Nitrate synthesis, the negative influence of nitrate ions on cubic phase stabilization of LLZO is also for the first time shown. The highest bulk conductivity, 0.211 mS/cm, is reached by solid-state synthesized LLZO sintered at 1200 °C for 12 hours.