Li-ion conduction in novel Scandium and Gallium doped Li 1.3 Al 0.29 Ga 0.005 Sc 0.005 Ti 1.7 (PO 4 ) 3 NASICON compound

Abstract Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP) has a high Li + conductivity of ~ 10 − 3 S/cm which can be employed as an inorganic solid electrolyte for solid state batteries. Here we report the electrical properties of gallium and scandium doped forms of LATP viz. Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP), Li 1.3 Al 0.29 Ga 0.01 Ti 1.7 (PO 4 ) 3 (LAGTP) and Li 1.3 Al 0.29 Sc 0.01 Ti 1.7 (PO 4 ) 3 (LASTP) and Li 1.3 Al 0.29 Ga 0.005 Sc 0.005 Ti 1.7 (PO 4 ) 3 (LAGSTP). All the samples were prepared by solid state reaction method. Structural characterization was carried out using X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) techniques whilst electrical properties were studied using Electrochemical Impedance Spectroscopy (EIS). It was found that the larger cations Ga 3+ and Sc 3+ at octahedral sites change the Ti–O–P bond angle in LTP lattice. This distortion of lattice on ion-ion correlation and subsequently on Li + ion conduction in the novel LAGSTP material was found to decrease the Li + ion conductivity to ~ 10 − 5 S/cm.