Ionic Conductivity and Dielectric Relaxation of NASICON Superionic Conductors at the Near-Cryogenic Regime

With a crystal lattice structure first characterized in the 1970s, NASICON sodium-based superionic conductors have recently found renewed interest as solid electrolytes sodium-ion and seawater flow batteries due to their exceptional ionic conductivity being on same scale liquid electrolytes. Since sodium ions move among interstitial positions through site-specific bottlenecks, overall is strongly dependent composition. In this work, we report synthesis protocols processing parameters of Na3Zr2Si2PO12 prepared from Na2CO3, SiO2, ZrO2, NH4H2PO4 precursors by conventional solid-state reaction (SSR) route. We critically evaluated important observations made extended literature topic including: (i) importance precursor particle size concerning SSR synthesis, focusing effective ball-milling protocols; (ii) onset excess zirconia contamination, expanding effects both thermal pressure processing—the latter often overlooked available literature. approaching cryogenic regime, dataset availability dielectric permittivity measurements for was extended, starting elevated temperatures at 200 °C reaching into very low temperature zone −100 °C.