Facile Synthesis of 3D Hierarchical Flower-like Co3-xFexO4 ferrite on Nickel Foam as High-Performance Electrodes for Supercapacitors

A facile hydrothermal method combined with a post solution reaction is developed to synthesize interconnected three-dimension (3D) hierarchical Co3-xFexO4 ferrite (CF) on nickel foam. By controlling the experimental parameters, the structures of the products are tailored from nanoflowers to microflowers with different sized void interiors. The obtained 3D hierarchical flower-like CF are characterized by field emission scanning electron microscopy, X-ray diffraction, and inductively coupled plasma mass spectrometer analysis. The 3D hierarchical flower-like CF-nickel foam with the rational structural feature could be used as binder and conductive agent-free supercapacitor electrodes directly. Such integrated electrodes exhibit a high specific capacitance and well cycling stability when the charge-discharge current density is high. Remarkably, the 3D hierarchical CF microflowers exhibit specific capacitance values of 768 F g−1 at a constant current density of 6 A g−1. The CF microflowers also show high charge-discharge reversibility with an efficiency of 79.2% after 5000 cycles.