INVESTIGATION OF SUPERCAPACITIVE BEHAVIOR OF COPPER-OXIDE BASED NANOSTRUCTURED FILMS

Nowadays the field of renewable energy is rapidly booming one of such example would be the European Union Green Deal whose goal is to make the European Union the first climate-neutral region in the world by 2050[1]. Although renewable energy provides many advantages it also comes with the obstacles such as non-continuity of energy production thus emphasising the necessity for cost-effective energy storage solutions. Copper, an abundant metal, offers solution, especially copper oxides. They do have an extremely high theoretical capacitance: Cu₂O 2247.6 F/g [2], CuO – 1783 F/g [3]. In our study, we have used cyclic voltammetry to anodize copper-oxide based thin-films on both porous and non-porous electrodes and electrochemical impedance spectroscopy (EIS) to characterize occurring electrochemical processes in 1M NaOH . We obtained their phase purity with the X-ray diffraction (XRD) method and surface morphology using scanning electron microscopy (SEM). It was observed that different oxide and hydroxide phases could be synthesized by tuning the upper vertex potential of the cycle (Fig. 1). The capacitance of electrodes was measured by cyclic voltammetry at different scan rates. The highest specific capacitance of 1380 mF/cm was obtained at the film synthesised on copper foam, vertex potentials: -1:0.65 V, at 5 mV/s scan rate. Therefore, the investigated methodology offers insights into the tunable synthesis of nanostructured copper oxide supercapacitors.