Superionic Solid Electrolyte Li₇La₃Zr₂O₁₂ Synthesis and Thermodynamics for Application in All-Solid-State Lithium-Ion Batteries

Li₇La₃Zr₂O₁₂Solid-state reaction was used for Li₇La₃Zr₂O₁₂ material synthesis from Li₂CO₃, La₂O₃ and ZrO₂ powders. Phase investigation by XRD, SEM and EDS methods of Li₇La₃Zr₂O₁₂ were carried out. The molar heat capacity of Li₇La₃Zr₂O₁₂ at constant pressure in the temperature range 298-800 K should be calculated as Cp,m = 518.135+0.599 × T - 8.339 × T−2, where T is absolute temperature, . Thermodynamic characteristics of Li₇La₃Zr₂O₁₂ were determined as next: entropy S0298 = 362.3 J mol-1 K-1, molar enthalpy of dissolution ΔdHLlZO = ˗ 1471.73 ± 29.39 kJ mol−1, the standard enthalpy of formation from elements ΔfH0 = ˗ 9327.65 ± 7.9 kJ mol−1, the standard Gibbs free energy of formation ∆f G0298 = ˗9435.6 kJ mol-1.