Interfacial Ion-Transport Mechanism of Li7(Al0.1)La3Zr2O12 Solid Electrolyte Modified by using a Spark Plasma Sintering Method

A novel interfacial in situ modification for Li-7(Al-0.1)La3Zr2O12 is designed and prepared by using a spark plasma sintering method. The modified interface with most grain boundary area exhibits excellent interfacial electrochemical properties. The X-ray diffraction (XRD) and scanning electron microscope (SEM) data indicate that the interfacial modified specimen (spark plasma sintering method, 1000 degrees C, 5 min) with 38.2(6) nm grain diameter and 32,134 cm(2)/g grain boundary specific surface area has the highest ionic conductivity (8.84 x10(4) S/cm(-1)). The lithium-ion transmission mechanism in grain-internal and grain boundaries is revealed by ab initio theory, using Materials Studio software. Furthermore, the first-principles calculation data indicate that the migration barrier of Li+ at the Li-7(Al-0.1)La3Zr2O12 solid electrolyte grain boundary is 0.21 eV, which is only 2/3 of that in the grain internal (0.33 eV). As a result, SPS interfacial in situ processing technology can increase the grain boundary area, thereby reducing the ion transport barrier and the interfacial impedance of the material.