A comprehensive study on rational design of Cu decorated Fe₃O₄@CeOHCO₃ with enhanced capacitance in supercapacitor applications

In this work, a novel Cu decorated Fe3O4@CeOHCO3 nanocomposite (Cu-Fe3O4@CeOHCO3) has been prepared by a one-step hydrothermal method. Fabricating into the electrode, the electrochemical properties of the prepared materials were characterized by cyclic voltammetry (CV), galvano-static charge-discharge (GCD) test and electrochemical impedance spectroscopy (EIS). The specific capacitance of the Cu-Fe3O4@CeOHCO3 electrode was 324.7 F g(-1) at a current density of 1.0 A g(-1) with a capacitive retention of 88.3% after 1000 charge-discharge cycles. The assembled asymmetric supercapacitor(ASC) device can provide an energy density of 35.4 W h kg(-1) with a high power density of 781.9 W kg(-1). DFT calculations prove that the surface modification of Cu functions significantly in modulating the electronic structure and super capacitive properties of CeOHCO3. Our self-assembled Cerium-based composite may initiate the suitability for energy storage devices and provides a valuable reference for the fabrication in sodium Ion supercapacitors. (C) 2021 Elsevier B.V. All rights reserved.