Activated carbon-supported lanthanum nickel oxide (LaNiO3 ) perovskite nanocomposite supercapacitor electrode material exhibiting superior power-density and life cycle

Abstract Perovskite LaNiO₃ was synthesized with the help of the sol-gel method and LaNiO₃@AC nanocomposite was produced via ultrasonication followed by filtration process keeping LaNiO₃ and activated carbon (AC) in an NMP solvent. The prepared electrode material was then coated on Ni foam with a mass loading of 28 mg/cm². Various well-known characterization techniques such as TGA, FTIR, XRD, FESEM, and XPS were used to characterize the crystal structure and surface morphology of the sample. The electrochemical performance of the prepared electrodes was measured with cyclic voltammetry (CV), galvanometric charge-discharge (GCD), and electrochemical spectroscopy (EIS) using 3 M KOH as an electrolyte solution in two electrode configurations. The pure LaNiO₃ electrode exhibits a specific capacitance (Cs) of 177.53 F/g at 5 mV/s, cyclic stability with 73.35% capacitance retention after 3000 cycles, energy density of 24.65 W h/kg, and a power density of 1.48 kW/kg. whereas, The LaNiO₃@AC nanocomposite electrode delivered a high Cs of 218.57 F/g at a 5 mV/s scan rate with excellent cyclic stability of about 94.57% specific capacitance retention after 3000 cycles, the outstanding energy density of 30.35 W h/kg with a high-power density of 1.58 kW/kg. Additional investigation on the storage contribution using Dunn's, b-fitting, and Randel Savic models produced superior results with the LaNiO₃@AC nanocomposite electrode than with the LaNiO₃ electrode. DFT analysis further demonstrated LaNiO₃ material's strong electrochemical characteristics and stability. Thus, the LaNiO₃@AC composite material can be the newest member of the supercapacitor electrode material with superior electrochemical performance.