Effect of Bi2O3 on the ion migration and interfacial properties of Li0.33La0.557TiO3 solid electrolytes

The poor interface incompatibility with Li anode and low ionic conductivity have hindered perovskite-type electrolyte’s practical application. In this work, solid electrolytes of Li0.33La0.557TiO3 + x wt% Bi2O3 for solid state batteries were prepared by solid-phase sintering method. The ionic conductivity of LLTO reaches a maximum of 2.71 × 10–5 S·cm–1 at 1 wt% Bi2O3 doping. The critical current density of Li0.33La0.557TiO3 + 1 wt%Bi2O3 can reach 0.16 mA and still operate normally after 300 h of cycling. Li0.33La0.557TiO3 + 1 wt% Bi2O3 solid-state battery displays a high initial discharge capacity of 133.1 mAh/g and capacity retention of 98.0% after 40 cycles.