Decoration of Hollow Mesoporous Carbon Spheres by NiCo₂S₄ Nanoparticles as Electrode Materials for Asymmetric Supercapacitors

Abstract

In this paper, seasame-ball-like core–shell hollow mesoporous carbon spheres decorated by NiCo2S4 nanoparticles (NiCo2S4/HMCSs) were prepared via a hydrothermal method. The obtained NiCo2S4/HMCSs could be used as the positive electrodes for asymmetric supercapacitors (ASCs), combining the outstanding electroconductivity of carbonic materials and high capacity of NiCo2S4 nanoparticles. The morphology and structure properties of the obtained NiCo2S4/HMCSs were characterized. The electrochemical properties of the as-obtained composites were characterized by an electrochemical workstation, showing an outstanding capacity of 1098.5 F g–1. Finally, ASCs were further fabricated by using the NiCo2S4/HMCSs as the cathode and hollow mesoporous carbon spheres (HMCSs) as the anode. Moreover, the assembled ASCs exhibited a good energy density of 35.1 Wh kg–1 at a moderate power density of about 203.5 W kg–1 and good cycle ability of ∼90% even after 3000 cycles.