High-performance energy storage hybrid supercapacitor device based on NiCoS@CNT@graphene composite electrode material

Abstract

The novel asymmetric supercapacitor, sometimes referred to as a ‘supercapattery,’ merges the favourable attributes of batteries, such as high energy density, with the exceptional cycle life and specific power of supercapacitors (SCs). In this study, carbon nanotubes and graphene were physically mixed with nickel cobalt sulfide (NiCoS), which was produced using a hydrothermal method. Using both a three-electrode and a two-electrode arrangement, the material’s electrical properties were carefully examined. The NiCoS@CNT@graphene composite exhibited a striking specific capacity (Qs) of 1814 C g−1 at 2 Ag−1, within the three-electrode system. The NiCoS@CNT@graphene//AC composite hybrid device revealed outstanding Qs of 190 Cg−1 at 2 Ag−1. Additionally, this material demonstrated an exceptional power density (Pd) of 2000 W kg−1 and a noteworthy Ed of 40.5 Wh Kg−1. The nanocomposite electrode showed remarkable capacity retention (CR ∼ 88%) after 5000 cycles, which was one of its most notable features, highlighting its long-term stability and potential for extensive usage. A viable strategy includes mixing transition metal sulfides with conductive carbon-based nanomaterials to produce high-performance energy storage devices with surpassed capabilities.