Investigation Of The Stability Of Nasicon-Type Solid Electrolyte In Neutral-Alkaline Aqueous Solutions

The effects of aqueous solutions with different pH values on the ionic conductivity of Na3Zr2Si2PO12 (NASICON) are studied at room temperature. The ionic conductivity of NASCION reduced severely in the solution with pH value of 7. The AC impedance method was used to study the changes of the bulk, grain boundary, and cracking surface resistances of the sample under different conditions. The electrolyte morphology, cell parameters, Na+ site occupancy fraction, and microscopic strain change were obtained by SEM and XRD data refinement. According to above analysis, the degradation processes of hydration, grain refinement, and surface cracking were observed gradually, the corresponding corrosion mechanism of NASICON in aqueous solutions was explained.