Capping assisted functionalization of Cobalt Ferrite CoFe2O4/MWCNTs composites by Celestine blue for high active mass loading supercapacitors

Abstract

The development of supercapacitor electrodes with high mass loading is essential for practical energy storage applications; however, it is commonly limited by the poor intrinsic conductivity and agglomeration tendency of transition metal oxides. In this work, high- performance cobalt ferrite (CoFe2O4)/multi-walled carbon nanotube (MWCNT) composite electrodes with a mass loading of 40 mg cm−2 were successfully fabricated. Celestine Blue (CB) was working as a bifunctional dispersant and interfacial linker to overcome the kinetic limitations. Electrochemical characterization showed that the optimized CB-modified electrode (CB10) exhibited reduced impedance and enhanced capacitive behavior relative to electrodes without dispersant, with a capacitance of 1.49 F cm−2 at 2 mV s−1 scan rate. An asymmetric supercapacitor device fabricated with the CoFe2O4–CB composite as anode and Mn3O4 as cathode operated over a voltage window of 1.5 V, delivered a maximum energy density of 9.96 Wh kg−1 and a power density of 320 W kg−1. The device also showed good cycling stability, and 88.9% capacitance retention after 2,000 cycles.