Effect of sintering temperature on Li diffusivity in Li0.29La0.57TiO3: Local hopping and long-range transport

The influence of sintering temperature on Li diffusivity was investigated for two Li0.29La0.57TiO3 samples sintered at 1400 °C and 1450 °C, respectively. Synchrotron radiation diffraction was used to get detailed insights into the crystal structure and the real structure and also into the subtle differences between the two samples. 7Li NMR relaxometry and 7Li PFG NMR were used to observe the local hopping of Li ions and the long-range transport, respectively. Our results show that the motion of Li ions inside the crystallites is very similar for both samples. The enhanced conductivity of the sample sintered at the higher temperature, as observed by impedance spectroscopy, is caused by the reduced density of grain boundaries. •Solid electrolytes Li0.29La0.57TiO3 show high Li-ion conductivity.•Influence of sintering temperature on structure and dynamics is observed.•Bulk conductivity is only slightly affected by sintering temperature.•Higher sintering temperature decreases concentration of grain boundaries and thus enhances conductivity.