Direct Ink Writing of Graphene-Cobalt Ferrite Hybrid Nanomaterial for Supercapacitor Electrodes

This work presents an approach for using direct writing of graphene-cobalt ferrite (GP-CoFe) as a hybrid electrode material in supercapacitors. First, the hybrid ink was prepared from an aqueous colloid of sodium dodecyl sulfate-functionalized graphene and cobalt ferrite nanoparticles. Second, the ink was printed on graphite paper substrates by using direct ink writing; then, the electrodes were treated in a microwave for different durations. As-printed electrodes were characterized by scanning electron microscopy; transmission electron microscopy, and serval electrochemical techniques, such as open-circuit voltage measurement, cyclic voltammetry, and electrochemical impedance spectroscopy. Finally, the GP-CoFe electrodes after microwave treatment for 60 min exhibited the highest specific capacitance of 304 F/g at a charge/discharge current density of 0.83 A/g, and good electrochemical durability with 94.68% capacitance retention after 16,000 cycles. This work thus provides an efficient method to fabricate a high-performance supercapacitor electrode. [GRAPHICS] .