The mechanical and electrical properties of Nb₂O₅doped Na-<i>β"</i>-Al₂O₃solid electrolyte

Abstract

It is well known that certain amounts of oxides doping can improve the ionic conductivity and mechanical properties of the Na-β"-Al2O3 solid electrolytes. In order to obtain high quality Na-β"-Al2O3 solid electrolytes, Nb2O5 doped Na-β"-Al2O3 solid electrolytes have been synthesized by double-zeta process. The effects of the Nb2O5 content on the microstructure, mechanical property and ionic conductivity of the Na-β"-Al2O3 are studied. The results show that the doping amount is the key factor to affect the properties of the final products. The optimal doping amount is 1 wt.%. The sample β"−1 contains 96.82% of β" phase, which is higher than that of the non-doped sample (95.31%). In addition, the relative density of the sample β"−1 is 98.93% (3.225 g/cm3), which contains a more uniform and compact microstructure. What is more, the sample β"−1 displays a bending strength up to 295 MPa and an ionic conductivity up to 0.153 S/cm (300 °C).