Synthesis and Characterization of Mg-Doped Na0.6Ni0.3-XMgxTi0.7O2 as Anode Material for Sodium Ion Battery

Abstract

Recently, sodium-ion batteries (SIB) have gained great amount of attention as a next generation rechargeable battery. The lithium-ion batteries (LIB) have been successfully commercialized and widely applied in electronic devices, vehicles, etc. due to its high energy density. Compared to LIB, SIB system is more desirable in view point of cost because the sodium source is more abundant and widely distribution. Similar to LIB, many studies about SIB cathode reported electrode materials with layered structure where Na ion can intercalate and deintercalate during electrochemical reaction. The electrodes with layered structure can also be utilized as anode. Although the theoretical capacity of layered material is generally lower than that of other materials which undergo conversion or alloying reaction, the electrode material with layered structure shows smaller volume change and better structure stability. Among many anode materials, NaxNix/2Ti1-x/2O2 has been reported to have layered structure with low operating voltage (~0.7V vs Na/Na+) and has shown promising performance. In this study, Mg and Ni was co-doped into NaTiO2 in order to study effect of Mg doping on anode performance. The Na0.6Ni0.3-xMgxTi0.7O2 was synthesized by simple solid-state synthesis method while varying Mg amount from x=0.0 to x=0.1. The structure change depending on the amount of Mg dopant was analyzed by high-resolution X-ray diffraction, scanning electron microscopy and electrochemical test were conducted to evaluate its performance.