Porous NiO/C Nanocomposites as Electrode Material\nfor Electrochemical Supercapacitors

Abstract

NiO/C nanocomposites were synthesized\nat different calcination\ntemperatures using starch as the stabilizing agent. The NiO/C nanocomposites\nwere characterized by thermogravimetric analysis (TGA), X-ray diffraction\n(XRD), Fourier transform infrared spectroscopy (FTIR), field emission\nscanning electron microscopy (FESEM), and transmission electron microscopy\n(TEM). The samples calcined at 500 °C exhibit a highly porous\nnature. Electrochemical investigations of NiO/C were carried out using\ncyclic voltammetry, chronopotentiometry, and electrochemical impedance\nspectroscopy. NiO/C-5 shows excellent electrochemical performance\ncompared to NiO/C-4 and NiO/C-6. The NiO/C-5 electrode exhibits a\nspecific capacitance value of 644 F g^–1 at a scan\nrate of 2 mV s^–1. The charge transfer resistance\nis 0.59 Ω for the NiO/C-5 electrode. This NiO/C-5 appears to\nbe a promising electrode material for supercapacitor applications.