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 900°C 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 600°C. 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 chargedischarge 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.