The effect of iron ion irradiation on the ionic conductivity of lithium lanthanum zirconium oxide garnet thin films

Abstract

The ionic conductivity of most lithium lanthanum zirconium oxide (LLZO, Li7La3Zr2O12) solid electrolytes requires improvement. In this study, LLZO thin films were fabricated through sputtering, and various doses of iron ion irradiation (Fe11+) were employed. As the irradiation dose increased from 1014 ions cm−2 to 1016 ions cm−2, the half-height width of the X-ray diffraction peak gradually broadened. Concurrently, the ionic conductivity increased from 2.3 × 10−9 S cm−1 to 2.4 × 10−5 S cm−1, while the activation energy decreased from 0.37 eV to 0.18 eV. The improved ionic conductivity can be attributed to the introduction of point defects in the microstructure of the LLZO thin film upon irradiation. Overall, the findings demonstrate the effective enhancement of the ionic conductivity of LLZO solid electrolytes through iron ion irradiation.