Superionic Solid Electrolyte LiLaZrO Synthesis and Thermodynamics for Application in All-Solid-State Lithium-Ion Batteries.

Solid-state reaction was used for LiLaZrO material synthesis from LiCO, LaO and ZrO powders. Phase investigation of LiLaZrO was carried out by x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) methods. The thermodynamic characteristics were investigated by calorimetry measurements. The molar heat capacity (), the standard enthalpy of formation from binary compounds (Δ) and from elements (Δ), entropy (), the Gibbs free energy of the LiLaZrO formation (∆ ) and the Gibbs free energy of the LLZO reaction with metallic Li (∆) were determined. The corresponding values are = 518.135 + 0.599 × T - 8.339 × T, (temperature range is 298-800 K), Δ = -186.4 kJ·mol, Δ = -9327.65 ± 7.9 kJ·mol, = 362.3 J·mol·K, ∆  = -9435.6 kJ·mol, and ∆ = 8.2 kJ·mol, respectively. Thermodynamic performance shows the possibility of LiLaZrO usage in lithium-ion batteries.