Influence of excess lithium and sintering on the conductivity of Li1.3Al0.3Ti1.7(PO4)3

NASICON-type samples with different amount of excess lithium content in starting materials, Li[Formula: see text]Al[Formula: see text]Ti[Formula: see text](PO 4 ) 3 ([Formula: see text]), were prepared by conventional solid-state reaction. Effect of excess lithium and sintering conditions on composition and electrical properties of LATP were investigated. X-ray diffraction and Scanning electron microscopy were used to characterize the composition, crystal structure and morphology, respectively. The total ionic conductivities of samples were measured by AC-impedance spectra. The optimal addition amount of excess Li was found to be 40[Formula: see text]mol.% with the highest conductivity of [Formula: see text][Formula: see text]S/cm at [Formula: see text]C. The improvement of the conductivity of LATP can be attributed to the increasing of Li[Formula: see text] carriers and the formation of glassy phase in samples which acted as binders and provided excess Li ion vacancies for lithium transport.