Synthesis of NASICON type Li<sub>1.4</sub>Al<sub>0.4</sub>Ge<sub>0.2</sub>Ti<sub>1.4</sub>(PO<sub>4</sub>)<sub>3</sub> solid electrolyte by rheological phase method
Fan Bai, Kouichi Kakimoto, Xuefu Shang, Daisuke Mori, Sou Taminato, Mitsuhiro Matsumoto, Yasuo Takeda, Osamu Yamamoto, Hironari Minami, Hiroaki Izumi, Nobuyuki Imanishi
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.