Reversible Behavior of K[sub 2]Fe(VI)O[sub 4] in Aqueous Media

The chemistry of the Fe(VI) compound, was investigated in aqueous potassium hydroxide electrolyte for its potential use in secondary storage systems. High charge storage material was synthesized using alkaline hypochlorite oxidation of ferric nitrate and characterized by in situ X-ray diffraction and Mössbauer spectroscopy. The discharge-charge profile of the cathode, measured vs. a zinc anode, was semiquantitatively correlated with changes in ratio and the nature of structural transformation at each stage by in situ Mössbauer and in situ synchrotron X-ray diffraction spectroscopy. The data in conjunction with the charge-discharge profile clearly indicates the rechargeability of with a charge efficiency of about 36% of the total current passed under the prevailing experimental conditions. These results are potentially important to the design of compound analogs for use in secondary energy storage systems.