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

Solid-state reaction was used for Li7La3Zr2O12 material synthesis from Li2CO3, La2O3 and ZrO2 powders. Phase investigation of Li7La3Zr2O12 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 (C-p,C-m), the standard enthalpy of formation from binary compounds (Delta H-ox(LLZO)) and from elements (Delta H-f(LLZO)), entropy (S-298(0)), the Gibbs free energy of the Li7La3Zr2O12 formation ( increment (f) G(298)(0)) and the Gibbs free energy of the LLZO reaction with metallic Li ( increment (r)G(LLZO/Li)) were determined. The corresponding values are C-p,C-m = 518.135 + 0.599 x T - 8.339 x T-2, (temperature range is 298-800 K), Delta H-ox(LLZO) = -186.4 kJ center dot mol(-1), Delta H-f(LLZO) = -9327.65 +/- 7.9 kJ center dot mol(-1), S-298(0) = 362.3 J center dot mol(-1)center dot K-1, increment (f) G(298)(0) = -9435.6 kJ center dot mol(-1), and increment (r)G(LLZO/Li) = 8.2 kJ center dot mol(-1), respectively. Thermodynamic performance shows the possibility of Li7La3Zr2O12 usage in lithium-ion batteries.

Automated summary

Solid-state reaction was used to synthesize Li7La3Zr2O12 material, and phase investigation was conducted using various methods. The thermodynamic performance suggests the potential application of Li7La3Zr2O12 in lithium-ion batteries.