Regular Article

The mechanical and electrical properties of Nb₂ O₅ doped Na-β"-Al₂O₃ solid electrolyte

¹ School of Materials Science and Engineering, Wuhan University of Technology, 430070 Wuhan, P.R. China
² Shandong Research and Design Institute of Industrial Ceramics Co., Ltd, 255031 Zibo, P.R. China

^a e-mail: jianghy@whut.edu.cn

Received: 8 September 2015
Revised: 10 November 2015
Accepted: 22 February 2016
Published online: 1 April 2016

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).