Synthesis and structural properties of sodium cobalt oxide

Abstract

Sodium transition-metal oxides with general formula NaxTMO2 (TM = Co, Mn, Ni, etc.) have attracted a lot of interest in the battery community due to low cost of sodium in contrast to lithium. Sodium cobalt oxide is the most attractive of them for cathode application because of its conductive, thermic and magnetic characteristics. In this study, sodium cobalt oxide, NaxCoO2 , was synthesized by simple method which involves solid state reaction in air, at temperature of 900 ºC; starting materials were Na2CO3 and Co3O4 in stoichiometric amounts. Additionally, fluorination of the synthesized sodium cobalt oxide was carried out in vacuum at 200ºC; NH4HF2 was used as a fluorine source. Then, structural and microstructural properties of the obtained powders were examined.