An ultrasound-assisted convenient method was developed for the synthesis of battery grade potassium ferrate (K2FeO4) with high yield (53-59%). The purity of the synthesized salt was determined by chromite method to be 95-96.8% It was found that sample of the solid potassium ferrate has a tetrahedral structure with a space group of D-2h (Pnma) froth X-ray diffraction (XRD) spectrum. From the scanning electronic microscopy (SEM), the K2FeO4 powders were crystallized polyhedron-shaped stick, and the particles had dimensions on the order of 25-200 mu m in length and 1-10 mu m in width. The electrochemical performance of the K2FeO4 electrodes was studied by using cyclic voltammetry and galvanostatic discharge methods in 10 mol/L. KOH aqueous electrolyte The synthesized product possesses a capacity of 302 4 mAh/g and coulombic efficiency of 74 5% (C) 2009 Elsevier Ltd All rights reserved