Synthesis of CNTs on ZnO/NiS composite as an advanced electrode material for high-performance supercapacitors

Abstract

The design and preparation of an efficient electrode material with a multifunctional surface structure is a key challenge for high-performance supercapacitors. In this study, ZnO/NiS and ZnO/NiS/CNT nanocomposites were synthesized on a nickel foam substrate and used as an electrode material. The surface morphology and structure of the electrodes were analyzed by field emission–scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The prepared nanocomposite of ZnO/NiS/CNT exhibited a high specific capacitance of 879.0 F g−1 at a current density of 1.5 A g−1, along with remarkable cycling stability of 89.7% capacitance retention after 5000 cycles, which was superior to that of ZnO/NiS (805.75 F g−1 and 74.59% retention). In addition, the ZnO/NiS/CNT electrode also exhibited good rate capability, faster ion and electron transfer ability, and higher surface area, highlighting its potential for electrochemical energy storage.