Effect of sintering conditions on perovskite lithium-based ion conductor

Perovskite lithium-based ion conductors, Li_0·33La_0·56TiO₃, were prepared by the solid-state reaction method. Various sintering temperatures and dwelling times were used to study their effects on the ionic conductivity. Scanning electron microscopy was carried out to study the microstructures, and electrochemical impedance spectroscopy was used to measure the ionic conductivity and transference number. The lithium ion transference numbers of the samples prepared in this study were all close to one. In certain range, a longer dwelling time was beneficial to the ionic conductivity, but the trend with dwelling time was not linear. A 12h-dwelling was found to be the best condition. A higher sintering temperature normally resulted in a dense morphology, which is definitely beneficial to the ionic conductivity. However the combination of higher temperature and longer dwelling time did not yield a better performance, which indicated that the influence of sintering conditions is far more complicated; therefore, optimal sintering conditions should be selected in specific situations.