Structural and electrochemical characterization of Sodium ion intercalation of the host material Na1.2V3O8

Abstract

Lithium ion batteries (LIBs) represent a real technological advancement in energy storage systems, with many applications in our daily life. In these days, in order to replace LIBs, there have been increasing efforts to develop next generation rechargeable batteries because of the scarceness of lithium resources and the limited theoretical capacity of LIBs. In this work, the electrochemical intercalation of sodium ions into the host material, Na1.2V3O8 has been studied, especially focusing on structural characterization. Na1.2V3O8 was obtained by a sol-gel method. The electrochemical characterization has been performed with 2-electrode home-made type cells. The working electrode consists of Na1.2V3O8 powder, Super P and PAN binder (8:1:1 in weight ratio), which was casted on Al foils. Activated Carbon was used as counter and reference electrodes. Non-aqueous solution of 1M NaClO4 was used as the electrolyte. These results have been obtained through the experiments of cyclic voltammetry, galvanostatic cycle, x-ray diffraction, electron scanning microscopy, energy dispersive x-ray spectroscopy, and elemental mapping. Synthesized Na1.2V3O8 powder was confirmed by X-ray diffraction using Rietveld refinement with GSAS program. The existence of intercalated sodium was confirmed by EDS and elemental mapping. After the cycle number of cells increases, there is no structural degradation. In order to determine the atomic positions of Na+ ions in the interstitial sites of the Na1.2V3O8, detailed structural analysis has been carried out, using the techniques of structure determination from powder X-ray data. ⓒ 2016 DGIST