Fabrication of Nasicon electrolytes from metal alkoxide derived gels

• Published in: Solid state ionics 1983-12, Vol.9-10, p.877-884
• Main Authors: Engell, John, Mortensen, Svend, Møller, Lone
• Format: Article
• Language: English
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/0167-2738(83)90105-4

Clear gels corresponding to several compositions in the Nasicon solid solution series have been prepared from dry phosphoric acid, tetraethylorthosilicate, zirconium propoxide and sodium methoxide all dissolved in propanol. The effects on the polymerization and gel formation of temperature, time, addition of water and order of mixing of the components have been studied. The crystallization of these gels and their usefulness as raw materials for the fabrication of dense ceramics of Nasicon have been investigated. For a Zr-poor Nasicon composition 97% of the theoretical density has been obtained at temperature below 1000°C. For a fixed ratio between Si and P, the temperatures needed to densify the ceramics increase with the Zr-content. The high temperature phase relations relevant to Nasicon have also been studied.