Improving ionic conductivity of Li0.35La0.55TiO3 ceramics by introducing Li7La3Zr2O12 sol into the precursor powder

Li0.35La0.55TiO3 (LLTO) powder was mixed with Li7La3Zr2O12 (LLZO) sol and finally sintered into ceramic pellets. In the low-temperature calcined precursor powder, Zr exists in the amorphous phase around LLTO aggregated particles. After high-temperature sintering, the LLZO phase does not exist, whereas Zr is doped into the LLTO grain interior but is richer in the grain boundary. The introduction of LLZO could modify the grain boundary region of the ceramics and thus change its electrical properties. The LLTO-based ceramics sintered at 1350 °C with 5 wt.% LLZO sol introduced in the precursor powder exhibit a high total conductivity of about 1.2 × 10− 4 S/cm at room temperature.

► LLTO ceramics exhibit a total conductivity of 1.2 × 10− 4 S/cm at room temperature. ► The brick layer model was used to calculate the specific grain boundary conductivity. ► The space-charge-layer effect was used to explain the enhancement on conductivity. ► A Li/LLTO–10 wt.% LLZO/Li configuration was assembled.