| Abstrakt: |
The unique electrochemical performance of the transition metal sulfide-based electrode materials attracts researchers to develop high-performance energy storage devices. In this line, Cobalt disulfide (CoS2) is found to be an efficient electrode material due to its excellent electrochemical stability, variable oxidation state of metal ions, and high redox activity. The present work focuses on the fabrication of high-performance asymmetric supercapacitor devices using two lab-made electrocatalysts viz., bare CoS2nanoparticles (NPs) and functionalized multiwalled carbon nanotube decorated cobalt sulfide (CoS2@f-MWCNT) nanocomposite (NCs). An in-depth investigation of electrochemical characteristics has been carried out for the CoS2NPs and CoS2@f-MWCNT NCs synthesized at 180 °C using a single-step hydrothermal technique, with cetyltrimethylammonium bromide (CTAB) as a surfactant. The electrochemical findings reveal that CoS2@f-MWCNT exhibits a higher specific capacitance (Cs) of ~623 Fg−1at 1 Ag−1and improved cycling stability with capacitance retention (CR) of ~97.4 % after 10,000 cycles at 5 Ag−1(vis-à-vis CoS2; Cs = 398 Fg−1and CR = 94.1 %). The asymmetric supercapacitor coin cells (ASC) fabricated from lab-made electro-catalysts, namely CoS2//AC, and CoS2@f-MWCNT//AC, demonstrating high power densities of ~982.6 and ~1113.0 Wkg−1, and energy densities of ~13.8 and 23.8 Whkg−1, respectively. Due to their superior electrochemical characteristics, CoS2@f-MWCNT//AC ASC device is utilized as a power supply unit for both the digital clock and six red light-emitting diodes (LEDs). The development of such a simple, straightforward, cost-effective, methodology for the preparation of CoS2@f-MWCNT nanoelectro-catalyst and fabrication of asymmetric supercapacitor devices with improved charge storage characteristics offers a foundation for the advancement of charge storage devices across various applications. |
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