Sol-gel method for synthesis of Li+-stabilized Na-v""-alumina for solid electrolytes in sodium-based batteries

Li+-stabilized Na-v""-alumina was synthesized through sol-gel based on the Pechini method with Al(NO3)3, NaNO3, and LiNO3 as the metal precursor. Evaluations were done to several different sodium content in order to counterbalance Na2O losses during sintering, as well as different sintering temperature between 1500 - 1700 °C. The evaluations were done by density measurement, impedance spectroscopy, X-ray diffraction, and Scanning Electron Microscopy. The synthesized powder exhibits Na-v""-alumina with measured relative density up to 2.96 ± 0.01 g/cm3. The ionic conductivity achieved was up to 0.23 S/cm at 300 °C with lowest activation energy for conduction of 0.17 eV. Moreover, the Na-v""-alumina phase content achieved was up to 83.8%.