Facile synthesis of CoCo2O4/rGO spinel nanoarray as a robust electrode for energy storage devices

Abstract

• Graphene based CoCo 2 O 4 nanostructure array was developed through hydrothermal route. • The electrochemical activity of CoCo 2 O 4 /rGO was performed for supercapacitor application. • The fabricated electrode CoCo 2 O 4 /rGO exhibited the specific capacitance of 1352.2 F g -1 with high energy density (E d ) of 75.96 Wh Kg -1 at low current density of 2 A g -1 . • The enhanced CoCo 2 O 4 /rGO was ascribed to the synergistic effect, diverse morphology and larger surface area. Pseudocapacitor electrodes made of spinel oxide nanomaterial is considered as a better solution to overcome the current energy crisis. In this work, CoCo 2 O 4 is fabricated and then combined with reduced graphene oxide (rGO) through clean hydrothermal method. The microscopic and spectroscopic tools were employed to examine the properties of the fabricated electrode material. The electrochemical activity of the material was determined by using polarization curves (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge methods (GCD) and chronoamperometry (CA). The electrochemical results revealed that the addition of rGO into CoCo 2 O 4 electrode, increases the discharge duration, improves its specific capacitance, and its extensive stability. The electrochemical results of CoCo 2 O 4 /rGO display the specific capacitance (Csp) of 1352.2 Fg -1 , energy density (E d ) of 75.96 Wh Kg -1 and power density (P d ) of 636 W Kg -1 at low current density of 2 Ag -1 . The nanocomposite exhibited the capacitance retaining of 98.22% over 2000 cycles and stable for 40 h. Though, the capacitive activity of fabricated electrode was further improved with change in electronic and structural arrangement, alteration in the morphology, or incorporation of other metal or non-metals.