Hierarchical CoFe₂O₄/NiFe₂O₄ nanocomposites with enhanced electrochemical capacitive properties

Hierarchical CoFe₂O₄/NiFe₂O₄ nanocomposites are prepared via a facile hydrothermal method, in which CoFe₂O₄ nanoparticles are coated by NiFe₂O₄ nanoparticles to form a novel nanostructure. Comparing with the single component of either CoFe₂O₄ electrodes or NiFe₂O₄ electrodes, the as-prepared hierarchical CoFe₂O₄/NiFe₂O₄ nanocomposites electrodes deliver a higher specific capacitance of 269 F g⁻¹ at a current density of 1 A g⁻¹ and exhibit capacity retention of 81% after 10000 charge–discharge cycles. The improved electrochemical performance demonstrates that hierarchical CoFe₂O₄/NiFe₂O₄ nanocomposites are promising materials and provide a new idea for future generation supercapacitors.