Boosted electrochemical properties of Co3O4 nanoflakes by the addition of a redox-additive electrolyte

Abstract

Abstract Metal oxide-based electrode materials and redox additive electrolytes hold great promise as essential components of energy storage devices and have a great impact on their overall performance. Co3O4 nanoflakes (NFs) have been prepared by a simple hydrothermal method. After thorough characterization of structure, functional group, and surface morphology, the potential of the as-prepared Co3O4 NFs is assessed as an electrode material for a supercapacitor. The powder XRD analysis confirms the formation of the spinel cubic phase and space group Fd 3 ‾ $\bar{3}$ m. Morphological studies showed prepared Co3O4 having nanoflakes-like structures and, with analysis by EDX, the presence of elemental composition has been confirmed. The electrochemical performance of the Co3O4 electrodes has been studied in three electrode configurations using a redox-additive electrolyte. The electrode demonstrates enhanced supercapacitor performance with a redox additive electrolyte due to the reversible oxidation states of Co2+/Co3+ and Fe2+/Fe3+, which significantly reinforced the Faradaic redox reaction. The CV curve has maintained its shape even at all scan rates, confirming the outstanding rate capability of the electrode. The Co3O4 electrode showed a greater specific capacitance (C sp) of 611.16 F g−1 at a current density of 10 A g−1 in a redox additive electrolyte solution and capacitance retentions up to 69.23 % after 10,000 cycles. The calculated charge transfer resistance (R ct ) of before and after GCD 10,000 cycles is obtained. The overall performance of the electrode material being consider as a promising candidate for supercapacitor applications.