NASICON-structured solid-state electrolyte Li1.5Al0.5-xGaxGe1.5(PO4)(3) prepared by microwave sintering

摘要

NASICON-structured Li1.5Al0.5Ge1.5(PO4)(3) (LAGP) has been a promising solid-state glass-ceramic electrolyte for all-solid-state lithium ion batteries. However, the non-ideal ionic conductivity, non-uniformity of chemical composition, distortion and micro-cracks, etc., have limited its practical application. Considering these issues, in this work, we first of all introduce partial substitution of Al3+ by Ga3+. To avoid segregation of secondary phase, microwave sintering technology to prepare LAGP was used. With the help of microwave irradiation, sintering could be finished in just 30 min, and the size of crystals was homogeneous across the cross-section. No distortion and micro-cracks could be identified. Characterisations such as DTA, XRD, SEM and EIS were used to evaluate the material and electrochemical properties of the Li1.5Al0.5-xGaxGe1.5(PO4)(3) (x = 0.1 - 0.5) samples. A high bulk conductivity of 6.67 x 10(-4) S/cm at room temperature has been achieved when x = 0.1 and the activation energy was about 0.66 eV.