Development of Li NASICON based Glass Ceramic Composites

Abstract

Evolution in the field of Ionics has been majorly due to its developments in the domains of energy storage and conversion. New cutting-edge materials for energy storage are being devised to keep up with the surging demand for clean energy. High Li+ newline ion conducting solid electrolytes have had newlinea paramount significance over time for their applications in all solid-state batteries. Ever since the development of Li+-NASICON, viz LiTi2(PO4)3 (abbreviated as LTP), scientists across the globe have been trying its possible use in electrochemical devices. However, high grain boundary impedance restricts its applications as total conductivity falls drastically. In order to tailor the grain boundary impedance, the present thesis deals with synthesis and characterization of Li+- newlineNASICON based glass-ceramics nanocomposites. These glass-ceramics are prepared by newlinemechanical milling assisted synthesis route by external dispersion of fast ionic/ mixed ionic electronic (MIE) glasses at the interface of LTP. Further, thesis explores the thermal stability and electrochemical stability of these newly developed glass-ceramics. newlineRigorous analysis has been done on mainly four kinds of system. The first two chapters deal with dispersion of fast ionic glass in Li+-NASICON while the latter two chapters discuss the dispersion of MIE glass in Li+-NASICON. The fast ionic glass chosen to be dispersed in LTP are (Li2SO4)- newline(LiPO3) (LSLP) and binary oxide glass i.e. 2LiCl-P2O5 (LCPO). Effect of compositional newlinealterations, sintering conditions and cooling process on electrical transport is investigated. The resulting Li+ newline-NASICON glass-ceramics are found to be thermally stable in a wide temperature newlinerange. They exhibit a total conductivity which was found to be 1-2 orders of magnitude higher than the pristine LTP. A nice correlation between structure and electrical transport could be established. The third system discusses the preparation and characterization of Li+-NASICON based glass ceramic showing MIE conduction.