Li1.5Al0.5Ti1.5(PO4)3 (LATP) is considered to be one of the promising solid-state electrolytes owing to its excellent chemical and thermal stability, wide potential range (~5.0 V), and high ionic conductivity (~10-4 S/cm). LATP powders are typically prepared via the sol-gel method by adding and mixing nitrate or alkoxide precursors with chelating agents. Here, the thermal properties, crystallinity, density, particle size, and distribution of LATP powders based on chelating agents (citric acid, acetylacetone, EDTA) are compared to find the optimal conditions for densely sintered LATP with high purity. In addition, the three types of LATP powders are utilized to prepare sintered solid electrolytes and observe the microstructure changes during the sintering process. The pyrolysis onset temperature and crystallization temperature of the powder samples are in the order AC-LATP > CA-LATP > ED-LATP, and the LATP powder utilizing citric acid exhibits the highest purity, as no secondary phase other than LiTi2PO4 phase is observed. LATP with citric acid and acetylacetone has a value close to the theoretical density (2.8 g/cm3) after sintering. In comparison, LATP with EDTA has a low sintered density (2.2 g/cm3) because of the generation of many pores after sintering.

1. Introduction
2. Experimental
3. Results and Discussion
4. Conclusion
Acknowledgement

• 류성준(단국대학교 에너지공학과) | SungJoon Ryu (Department of Energy Engineering, Dankook University, Cheonan 31116, Republic of Korea)
• 최슬기(단국대학교 에너지공학과) | Seul Ki Choi (Department of Energy Engineering, Dankook University, Cheonan 31116, Republic of Korea)
• 원종호(단국대학교 에너지공학과) | Jong Ho Won (Department of Energy Engineering, Dankook University, Cheonan 31116, Republic of Korea) Corresponding Author
• 양민호(단국대학교 에너지공학과) | MinHo Yang (Department of Energy Engineering, Dankook University, Cheonan 31116, Republic of Korea) Corresponding Author