Boosting electrochemical properties of Li0.33La0.55TiO3-based electrolytes with Ag incorporation

Perovskite Li0.33AgxLa0.557-xTiO3 electrolytes were prepared using sol-gel chemical reaction, which was used as the intermediate layer of all solid-state rechargeable lithium batteries. The effects of Ag+ content on the microstructures and electrochemical impedance properties of Li0.33La0.55TiO3 (LLTO) were studied. The ionic conductivities of 1.54 x 10-4 S/cm at room temperature and 1.6 x 10-3 S/cm at 358 K were obtained for the Li0.33Ag0.10La0.457TiO3 sample, respectively. The improvement in conductivities was attributed to the structural integrity of LLTO electrolytes and the bottleneck size of Li+ ions was expanded. Meanwhile, The Ag inclusions at grain boundaries reduced the grain boundary resistance, resulting in a significant increase in the conductivity of LLTO. This work proves that the large dielectric constant was due to the Li+ ions dipole inside the electrolyte and the interfacial polarization of lithium-ion accumulation near the grain boundary. The Ag incorporation was an effective method for improving the resistance of lithium-ion battery electrolytes.