LAYERED O3-NaFe0.5Co0.5O2 AS HIGH CAPACITY AND LOW- COST MATERIAL FOR SODIUM ION BATTERIES

Abstract

In this work, O3-NaFe0.5Co0.5O2 layered cathode material was synthesized by solid state reaction at 900oC followed by a quenching step at 600oC in argon atmosphere. X-rays diffraction patterns indicated that O3-layered structure could be maintained after a quenching process at 600oC. The chemical composition and morphology of the synthesized material were analyzed by Atomic Absorption Spectroscopy (AAS) and Scanning Electron Microscopy (SEM). The electrochemical properties were evaluated by Cyclic Voltammetry (CV) and charge-discharge cycling. The material NaFe0.5Co0.5O2 shows the sloped discharge curves with high flat voltage plateau and excellent cycling stability. The reversible capacity of about 120 mAh/g at rate C/10 and good capacity retention after 100 cycles were obtained. The rate capability of material was investigated at the current density up to 2 C in voltage range 2.5-4 V.