مهتاب خاكباز

This study focuses on the synthesis and characterization of Li3OCl antiperovskite electrolyte using a solid-state method. LiOH and LiCl powder mixtures with a stoichiometric ratio of 2:1 were utilized as raw materials. The samples were exposed to heating under vacuum conditions at 265 °C for various durations, ranging from 24 to 96 hours. XRD tests were also conducted under a simulated condition, which is similar to synthesis process to investigate different stages of Li3OCl synthesis. The thermal stability of the synthesized material was eva‎luated by DSC, TGA, and DTA tests. EIS measurements were performed over a temperature range starting from approximately 260°C to lower temperatures. The XRD results, subjected to samples with a synthesis duration of only 24 hours revealed that weak peaks corresponding to Li3OCl appeared alongside side phases such as Li2OHCl, Li4Cl(OH)3, and residual LiCl. Extending the synthesis time did not significantly change the phase composition until reaching 72 hours. However, noticeable enhancements in peak intensities related to Li3OCl occurred. After 96 hours, strong signals indicative of dominant Li3OCl phase within the sample were observed. Observations during cooling process indicated reappearances of hydroxide phases such as Li2OHCl and Li5(OH)2Cl3. Below 100 °C, an amorphous background was observed alongside intensified peaks associated with the Li4Cl(OH)3 phase. Confirmation of OH bonds, indicating absorbed moisture within the crystal structure was obtained through additional FTIR analysis. DSC and DTA analysis, exhibited glass transition behavior at approximately 78 °C and melting peaks attributed to Li3OCl and either phases of hydroxide or sub-lattice. TGA analysis supported these findings by increased weight of Li3OCl due to the absorbance of moisture below 100°C and subsequent weight loss above this temperature range. EIS spectra displayed increasing bulk and grain boundary resistance as the temperature decreased, demonstrating increased diffusion activation energy caused by lower temperatures. The ionic conductivity of the material ranged from 3.24×10-3 S.cm-1 to 7×10-8 S.cm-1 between 260 °C to 60 °C with non-Arrhenius behavior observed at certain temperatures.

باتري‌هاي ليتيوم-يوني , Li3OCl , سنتز حالت جامد , پايداري فاز , هدايت يوني

Lithium-ion batteries , Li3OCl , Solid-state synthesis , Phase stability , Ionic conductivity

Mahtab Khakbaz

Dr.Afshin Namiranian