Development and characterizations of Bi2O3-containing glass–ceramic sealants for sodium sulfur battery

• We develop a new series of Bi2O3-containning glass–ceramic sealants for sodium sulfur battery.
• The crystallization behavior and joining properties of the glass–ceramics were studied.
• It was supposed that small size Bi2Ti2O7 crystal enhanced corrosion resistance against sulfur.

Bi2O3-containing glass–ceramic sealants for sodium sulfur battery are developed by doping the nucleating agent TiO2. The crystallization behavior of the glasses with the dopants is studied. The addition of nucleating agent TiO2 induces the precipitation of Bi2Ti2O7 crystal. The thermal expansion match between the Bi2O3-containing glass–ceramics and the α-, β-Al2O3 is relatively satisfactory. The joining properties of the sealants involving the bonding strength, thermal shock resistance, chemical stability and corrosion resistance are evaluated. No microcracks were observed in the AC5/α-, β-Al2O3 joint after 200-times thermal shock between 350 °C and room temperature. The thickness of diffusion layer was about 10 μm after holding at 350 °C for 200 h. Moreover, the existence of small size crystalline Bi2Ti2O7 phase reasonably enhances the sulfur corrosion resistance.