Sol-Gel mediated synthesis of Sb5+-doped nickel cobaltite (NiCo2O4) spinel structures: unveiling the role of Sb5+ in enhancing the specific capacitance of NiCo2O4

The function of antimony (Sb) in NiCo₂O₄ nanocrystals as supercapacitor electrodes is thoroughly examined in this work. XRD refinements were used to characterize the materials to determine their crystal parameters. BET surface area was increased while Sb concentration rose and reached 194.18 m²/g for 5 % Sb: NiCo₂O₄. Electrochemical functionality was investigated using electrochemical impedance spectroscopy (EIS), galvanostatic charge–discharge (GCD), and cyclic voltammetry (CV). A high specific capacitance of 1449F/g and strong capacitance retention of around 85 % after 3000 cycle runs are displayed by the 5 % Sb: NiCo₂O₄ electrode material at a current density of 0.5 A/g. 5 % Sb: NiCo₂O₄ electrode material had a greater energy density of 38.61 Wh/kg and a power density of 643.9 W/kg. According to EIS, the charge transfer resistance (R_ct) and series resistance (R_s) were reduced upon Sb doping and reaching to 2.59 Ω and 0.0591 Ω respectively, for 5 % Sb: NiCo₂O₄ electrode material.