One-Dimensional Nise-Se Hollow Nanotubular Architecture As a Binder-Free Cathode with Enhanced Redox Reactions for High-Performance Hybrid Supercapacitors
Suvani Subhadarshini
Abstract
Selenium-enriched\nnickel selenide (NiSe–Se) nanotubes supported\non highly conductive nickel foam (NiSe–Se@Ni foam) were synthesized\nusing chemical bath deposition with the aid of lithium chloride as\na shape-directing agent. The uniformly grown NiSe–Se@Ni foam,\nwith its large number of electroactive sites, facilitated rapid diffusion\nand charge transport. The NiSe–Se@Ni foam electrode exhibited\na superior specific capacitance value of 2447.46 F g<sup>–1</sup> at a current density value of 1 A g<sup>–1</sup> in 1 M aqueous\nKOH electrolyte. Furthermore, a high-energy-density pouch-type hybrid\nsupercapacitor (HSC) device was fabricated using the proposed NiSe–Se@Ni\nfoam as the positive electrode, activated carbon on Ni foam as the\nnegative electrode, and a filter paper separator soaked in 1 M KOH\nelectrolyte solution. The HSC delivered a specific capacitance of\n84.10 F g<sup>–1</sup> at a current density of 4 mA cm<sup>–2</sup> with an energy density of 29.90 W h kg<sup>–1</sup> at a power density of 594.46 W kg<sup>–1</sup> for an extended\noperating voltage window of 1.6 V. In addition, the HSC exhibited\nexcellent cycling stability with a capacitance retention of 95.09%\nafter 10,000 cycles, highlighting its excellent potential for use\nin the hands-on applications. The real-life practicality of the HSC\nwas tested by using it to power a red light-emitting diode.