Facile synthesis of uniform nanoporous CuCo2S4 hollow microspheres as a novel electrode material for high-performance supercapacitors

Today Among the various energy storage devices supercapacitor (SCs) possessing higher energy density than conventional capacitors, more power densities than Li-ion batteries high safety long cycle life, less thermochemical heat generation and easy mode of operation and integration have been attracted much more attention for application in various portable devices. Recently metallic sulfides (such as NiCo2S4, MnCo2S4 etc.) have been intensely applied as electrode material due to greater electrical conductivity than metal oxides. It is accepted that by substituting oxygen with sulfur possessing lower electronegativity can effetely facilitate the electrons transfer in electrodes and consequently enhance electrical conductivity power performance of the electrodes. Herein, for the first time we developed a new electrodes from nanoporous CuCo2S4 hollow microspheres with an average diameter of around 500 nm and evaluated their electrochemical properties for high-performance supercapacitor. These hollow microspheres were synthesized through facile and low cost two-step hydrothermal method. The crystalline nature, nanoporous structure and hollow interior of the microspheres were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), and transmission electron microscopy (TEM) techniques. Electrochemical evaluation of the as-prepared CuCo2S4 electrodes was performed by galvanostatic charge-discharge and cyclic voltammetry (CV) the electrodes exhibited a high specific capacitance of 1576 F g-1 at a current density of 2 A g-1, excellent good rate capability, and an remarkable cycling stability of 91% after 5000 cycles.