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. Co 3 O 4 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 Co 3 O 4 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 <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <m:mrow> <m:mover accent="true"> <m:mn>3</m:mn> <m:mo>‾</m:mo> </m:mover> </m:mrow> </m:math> $\bar{3}$ m . Morphological studies showed prepared Co 3 O 4 having nanoflakes-like structures and, with analysis by EDX, the presence of elemental composition has been confirmed. The electrochemical performance of the Co 3 O 4 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 Co 2+ /Co 3+ and Fe 2+/ Fe 3+ , 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 Co 3 O 4 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.

Topics & Concepts