Synergistic effect of Cr2O3 and Co3O4 nanocomposite electrode for high performance supercapacitor applications

The fabrication of high performance supercapacitor electrodes has been greatly investigated for future high power storage applications. In this present work, chromium oxide-cobalt oxide based nanocomposite (Cr₂O₃–Co₃O₄ NC) was synthesized using the hydrothermal approach. Moreover, the cyclic voltammetry (CV) study reveals the Cr₂O₃–Co₃O₄ NC delivers a high specific capacitance of 619.4 F/g at 10 mV/s. The electrochemical impedance spectra (EIS) of Cr₂O₃–Co₃O₄ NC possess the solution resistance (R_s) and charge transfer resistance (R_ct) of 0.68 Ω and 0.03 Ω respectively. The Galvanostatic charge-discharge (GCD) analysis demonstrated the prolonged charge-discharge time and good rate capability of the Cr₂O₃–Co₃O₄ NC. The cyclic stability of Cr₂O₃–Co₃O₄ NC delivers superior capacitive retention of 83% even after 2000 cycles. The asymmetric supercapacitor (ASC) device based on Cr₂O₃–Co₃O₄//AC yielded an energy density of 4.3 Wh/kg at the corresponding power density of 200 W/kg. Furthermore, the ASC delivers superior cyclic stability of 74.8% even after 1000 consecutive charge-discharge cycles.