Sodium beta alumina ceramics (Na1.67Al10.67Li0.33O17) is used in sodium
sulphur batteries as solid electrolyte. In the present work, sodium beta
alumina powder has been synthesized by the solid state method using Al2O3,
Na2CO3 and Li2CO3 as the starting materials. The effect of nanosized SnO2
additive on sintering behaviour, microstructure, mechanical and electrical
properties of sodium beta alumina ceramics has been investigated. The
results indicated that the addition of 1mol% of nanosized SnO2 particles,
determined as the optimal amount, can decrease the sintering temperature of
sodium beta alumina ceramics for about 100?C, and lead to the excellent
densification and proper microstructure, as well. Improvement in sintering
behaviour of beta alumina ceramics in the presence of nanosized SnO2
additive is apparently due to the formation of a liquid phase during the
sintering process and lower sodium loss. The results also proved that by
SnO2 addition, ionic conductivity at 300?C, fracture strength and Weibull
modulus of the sintered samples are improved by 66%, 58%, and 45%,
respectively. These improvements could be attributed to the higher amount of
???-Al2O3 phase, higher density and more uniform microstructure.