Synthesis of Na⁺ Superionic Conductors in the Na₂O-Y₂O₃-P₂O₅-SiO₂ System by using metal alkoxides and Crystallization Processes from Dried Gel

Abstract

Sodium superionic conductor with the composition of Na_5.2Y_0.8P_0.4Si_3.6O_12.0 was synthesized using metal alkoxides. When a usual synthetic method, using every alkoxide, water, solvent and catalyst directly, was employed as a sol-gel method, the highly conductive silicophosphate was obtained, but a nitrate was precipitated in the dried gel. On the other hand, the dried gel obtained after the gelation was induced by moisture in air was highly homogeneous and showed lowering temperature of crystallization.