Abstract 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.

中文翻译：

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NASICON 型固体电解质在中性碱性水溶液中的稳定性研究

摘要 研究了室温下不同pH值的水溶液对Na3Zr2Si2PO12(NASICON)离子电导率的影响。NASCION的离子电导率在pH值为7的溶液中严重降低。采用交流阻抗法研究了样品在不同条件下的体积、晶界和裂纹表面电阻的变化。通过SEM和XRD数据精修获得电解质形态、电池参数、Na+位点占有率和微观应变变化。根据以上分析，逐渐观察到水化、晶粒细化和表面开裂的降解过程，解释了NASICON在水溶液中的相应腐蚀机理。