Electrodeposited Cobalt–Copper mixed oxides for supercapacitor electrodes and investigation of the Co/Cu ratio on the electrochemical performance

Abstract

AbstractIn this study, different Cobalt–Copper mixed oxides compositions for supercapacitor electrodes have been prepared, by means of electrodeposition and thermal annealing. The chemical–physical and electrochemical characterization of electrodes, as well as the effect of different Co/Cu in the ratios on the crystal lattice, electrode morphologies, and electrochemical performance of the electrodes, were investigated using X-ray diffraction (XRD), scanning electron microscopic (SEM) and cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge (GCD) tests. The results indicated that the electrode prepared from 0.06 M CoSO4·7H2O + 0.04 M CuSO4·5H2O solution (CC4) had a better electrochemical performance. The initial capacity of the CC4 electrode was 28.3 mAh/g at a scan rate of 5 mV/s with a coulombic efficiency of 94%. CC4 electrode featured capacity retention of 79.2% at a constant current density of 1 A/g after 5000 cycles.