Ionic conductivity of Na-NASICON glass ceramics obtained at different temperatures

• Grant number: 17/16765-7
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): December 01, 2017
• Effective date (End): November 30, 2018
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal researcher: Ana Candida Martins Rodrigues
• Grantee: Amanda Daniele Fulanetto
• Home Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass, AP.CEPID

Abstract

Due to the constant search for alternative energy sources and their storage, sodium batteries appear promissor because of sodium low cost, high availability and low toxicity. Therefore, the development of materials with high sodium-ionic conductivity for use as solid electrolytes in batteries and other electrochemical devices is of great technological interest. Materials with NASICON structure are widely investigated for applications as solid electrolyte, since this structure has channels that allow the easy displacement of charge carriers, with low activation energy. It has been observed in a study carried out in the Laboratory of Vitreous Materials at UFSCar that glass-ceramic in the NASICON Na1 + xAlxTi2-x (PO4)3 series present suitable conductivities (of the order of 10-3 (&.cm) -1 in 300°C) to be used as solid electrolytes in sodium batteries operating at medium temperatures. In previous works in the group, the best conductivities were verified in the glass ceramic with composition Na2.0Al1.0Ti1.0 (PO4)3 and Na2.2Al1.2Ti0.8 (PO4)3. In this sense, to further improve the conductivity of these materials, the present work proposes to synthesize glass ceramics of these compositions from thermal treatments performed in precursor glasses at temperatures above the crystallization temperature of each glass to promote an increase in grain size of the glass ceramics, reducing the interfacial area and therefore the grain boundaries and thus, trying to improve the ionic conductivity of these materials. (AU)