Construction of a ternary composite of mg-doped biochar/CuO, and PAni for supercapacitor applications

Here, the biochar particles obtained by CuO-functionalized from orange peel wastes are modified by magnesium–doping by co–precipitation method (PAni@Mg–OP/CuO) for use as a supercapacitor. The electrochemical performance of electrode materials is systematically investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge/discharge (GCD) in the presence of 1 M H2SO4 as electrolyte. The PAni@Mg–OP/CuO electrode shows excellent stability with high specific capacitance up to 702.8 F.g−1 at 1.0 A.g−1 and 91.3 % retention after 8000 continuous galvanostatic charge/discharge (GCD) cycles. Furthermore, FTIR, XPS, XRD, TGA, UV–Vis, SEM, EDS and nitrogen adsorption/desorption analyses are used for the characterization of the obtained samples. Based on a significant supercapacitor performance, the synthesis strategy of biochar-based electrode material containing Mg and CuO modifications derived from agricultural biomass waste material is predicted to be a valuable example. [Display omitted] •The supercapacitor performance of prepared electrodes was investigated as electrode material for supercapacitor.•The capacitance of PAni@Mg–OP/CuO electrode was achieved as high as 702.8 F·g−1 at a current density of 1.0 A.g−1.•PAni@Mg–OP/CuO based electrode showing the energy density of 37.5 Wh.kg−1 at current density of 1.0 A.g−1.•Power density was found to be 328.2 W.kg−1 at current density of 1.0 A g−1.•PAni@Mg–OP/CuO presented a capacitance retention of 91.3 % after 8000 cycles at a current density of 1.0 A.g−1.