Abstract: As the key material of the β-Al₂O₃ electrolyte of sodium sulfur battery(SSB), the properties of Na-β-Al₂O₃ powders play an important role in the performance of SSB. In this study, nanosized Na-β-Al₂O₃ powders were prepared by Sol-Gel process with polyvinyl pyrrolidone (PVP) as the chelating agent. The phase formation temperature of the Na-β-Al₂O₃ by the PVP-based process was reduced to 900℃, which was much lower than those of conventional SSR and most chemical synthesis methods. The new method can effectively inhibit the performance decline of the Na-β-Al₂O₃ ceramics induced by the volatilization of Na₂O at high temperature in the conventional method. The powders were characterized by XRD, SEM and TEM techniques. It was demonstrated that the phase was pure and the particles were well dispersed with diameter of 60-70 nm, which were helpful to the good performance of Na-β-Al₂O₃ ceramics. In addition, the conductivities of the Na-β-Al₂O₃ ceramics sintered by the as-prepared powders were measured by AC impedance spectroscope and the evaluation of the spectra was carried out with increasing temperature from room temperature to 350℃. The electrical conductivity of the ceramics at 350℃ reached 0.22 S/cm.

Key words: PVP, Sol-Gel process, nano-powders, Na-β-Al₂O₃