Development of high ionic-conductive Li<sub>1.5</sub>Al<sub>0.5</sub>Ge<sub>1.5</sub>(PO<sub>4</sub>)<sub>3</ sub> glass-ceramic solid electrolyte sheet at low temperature using glass/powder composite

Abstract

Because of some drawbacks of the organic electrolytes, such as high toxicity and flammability, inorganic electrolytes have attracted attention regarding applications in all-solid-state rechargeable batteries. However, the fabrication of such electrolytes generally requires high sintering temperatures. To address this issue, in this study, ceramic sheets of Li1.5Al0.5Ge1.5(PO4)(3) (LAGP)-based solid electrolyte were prepared using glass, powder, and a glass/powder composite. The use of LAGP and glass-ceramic enabled the prepared sheets to be sintered at a low temperature of 750 degrees C. The obtained LAGP-based solid electrolytes had the trigonal structure of sodium superionic conductor (NASICON). The LAGP glass/powder composite ceramic sheet (GPCS) exhibited fewer pores and a higher density than the glass-only and powder-only sheets. Owing to its high crystallinity and density, the LAGP_GPCS exhibited total ionic conductivity of 4.52 x 10(-4) S/cm, which is exceedingly high compared with that of the other two sheets. This finding confirms that the ionic conductivity of LAGP can be increased by using simple composites. Thus, LAGP_GPCS can improve the efficiency of electric vehicles and smart grid energy storage systems, which rely on high-performance all-solid-state rechargeable batteries.