Simple, Low-Cost Synthesis of an Iron Oxide and Carbon Foam Composite for Supercapacitor Electrodes

Iron oxide-carbon foam (IOCF) materials with a high specific surface area and conductivity have been synthesized via a facile, cost-effective, and one-step template-free method. The structure and morphology of the IOCF composite have been investigated by electron microscopy, cyclic voltammetry, and Raman spectroscopy.  The as-prepared IOCF was coated on a nickel metal foam electrode as an active material for constructing supercapacitor electrodes. The electrochemical performance of IOCF composite electrodes was tested by cyclic voltammetry and galvanostatic charge/discharge in a Na₂SO₄ electrolyte. The as-assembled symmetric supercapacitor with optimal mass ratio can be operated reversibly over a wide voltage range of 0 to -1.0 V, and presents a high capacitance of 170 F g^-1 in Na₂SO₄ aqueous electrolyte. Moreover, the supercapacitor exhibits excellent rate capability and retains a high capacity with extended cycling. These attractive results make this material promising as a component of an aqueous electrolyte-based supercapacitor having high energy and power densities.