The main goal of this project is the study of the relationship between the structure and dynamics of fast sodium ion conductors for applications as solid electrolytes and electrode materials tuning application-relevant physical properties of such systems in a controlled manner, for improved energy storage capacity and reversibility.The present proposal focuses on characterizing the structural and dynamical features of superionic glass-ceramic electrolyte systems with lithium and sodium ions having extremely high ionic mobilities. These systems, which crystallize in the hexagonal Na-Super Ion Conductor (NASICON) structure, are derived from the superionic phase MTi 2 (PO 4 ) 3 (M = Li, Na). For the structural analysis of glasses and ceramics and for characterizing echanistic details of ionic movement in such systems, modern high-resolution Nuclear Magnetic Resonance (NMR) spectroscopic methods will be used. Multinuclear single- and double resonance NMR work will be done to investigate in detail the local environments of both the framework nuclei ( 31 P, 29 Si, 27 Al, 119 Sn) and the mobile ions ( 6/7 Li, 23 Na) in the glassy state, and their evolution during the ceramization process. In addition, the local ion dynamics of the lithium and sodium ions will be characterized by temperature dependent NMR lineshape and multidimensional correlation functions and related to the structural features of these materials. In this manner, the effect of iso- and aliovalent cation substitution in the framework structure as well as of alkaline ion mixing on the cation sites will be characterized and correlated with the results of electrical conductivity measurements.
News published in Agência FAPESP Newsletter about the scholarship: