Abstract
Supercapacitors are promising energy storage systems as they offer low cost, high cyclic stability, and high-power density. However, at high currents, due to high voltage drops they show a consequent low energy density and irregular stability problems. Herein, we demonstrate a device that addresses these problems by vanadium-doped Co-Ni spinel ferrite nanoparticles (SFNP) (Co(0.5)Ni(0.5)VxFe(2)_ xO(4)) where x = 0.00, 0.04, 0.08 and 0.10 into an activated carbon-based nanocomposite electrode. The fabricated supercapacitor device showed a successful energy density retention at high current without losing power density and cyclic stability. The device containing SFNPs based composite electrodes was achieved a specific energy of 57.24 Wh kg(-1) at a specific power of 7.900 W kg(-1) with excellent cyclic stability of 10,000 cycles. The prototype device was successfully powered RGB LED light. The low-cost production of materials and high electrochemical performance may pave the way for using these nanocomposites for highly stable energy storage devices.