Synthesis of NASICON type Li1.4Al0.4Ge0.2Ti1.4(PO4)3 solid electrolyte by rheological phase method

Abstract

NASICON-type Li1.4Al0.4Ge0.2Ti1.4(PO4)3 solid electrolyte (AG-SE) was synthesized using a rheological phase method precursor. The AG-SE powders prepared by this method had a low crystalline temperature of 595.5°C and much fewer impurity phases than that prepared by the conventional solid-state method. An AG-SE pellet sintered at 900°C for 14 h had a high relative density of 95.3%, with total and grain boundary room temperature conductivities of 1.21 and 4.35 mS cm−1 individually. The total activation energy for the AG-SE was as low as 0.29 eV. The 3-point bending strength was determined to be 102 N/mm2, which was higher than that of AG-SE prepared by solid-state and liquid-phase method precursors.