Studying of superionic solid electrolyte Li7La3Zr2O12 stability by means of chemical thermodynamics for application in all-solid-state batteries

Abstract

Li7La3Zr2O12 is a promising solid electrolyte for high-energy lithium and lithium-ion power sources, including all-solid-state batteries, so its stability to electrode materials and different environments over a wide temperature range attracts researchers’ attention. Thermodynamic simulation can be considered an express and convenient technique to estimate the thermodynamic stability of substances. Thermodynamic simulations of the Li7La3Zr2O12 stability against some electrode materials (LiCoO2, LiFePO4, LiMn2O4, Li4Ti5O12 and Li) and environment components have been carried out. According to the simulation results, the Li7La3Zr2O12 solid electrolyte is stable against metallic lithium in a wide temperature range. However, it has high reactivity with Li4Ti5O12 and all the studied cathode materials, with the exception of LiMn2O4 at room temperature. In addition, according to thermodynamic simulation data, Li7La3Zr2O12 reacts with carbon dioxide and water to form carbonates and hydroxides, respectively. The results of thermodynamic simulation are in good agreement with the experimental data, and it can be concluded that the proposed methodology is quite reliable and can be applied to the reactivity estimation of solid electrolytes.