NiSe₂@CdO Nanocomposite: A Next-Generation Electrode for Asymmetric Supercapacitors with Gel Electrolyte

This article investigates the electrochemical performance of NiSe₂@CdO nanocomposites synthesized by combining melt-diffusion-synthesized NiSe₂ and hydrothermally prepared CdO, followed by ball milling to obtain the final NiSe₂@CdO composite. Structural, morphological, and electrochemical analyses revealed flake-like NiSe₂ nanoparticles decorated with rod-shaped CdO nanostructures, exhibiting exceptional electrochemical performance. The nanocomposite electrode achieved a specific capacitance of 255 F/g at 10 mV/s from the three-electrode setup, and also, was achieved at an energy density of 48 Wh/kg at the power density 2000 W/kg by the NiSe₂@CdO||AC asymmetric device. fourier transform infrared analysis confirmed the structural integrity, while transmission electron microscopy images revealed nanostructures with clear lattice fringes, and energy-dispersive X-ray Spectroscopy verified elemental uniformity. The device demonstrated 96.7% capacitance retention even after 5000 cycles and displayed superior energy and power density characteristics in the Ragone plot. These results in turn, highlight the potential of NiSe₂@CdO nanocomposites for next-generation energy storage systems.