ZnO@NiCo-LDH core-shell nanostructures grown on carbon cloth for high-performance flexible supercapacitor electrodes

Abstract

ABSTRACT The ZnO@NiCo-LDH core-shell nanostructures on carbon cloth (CC) are synthesised by a combination of hydrothermal and electrochemical deposition method. The effects of deposition times on the morphology, structure and electrochemical properties of the product are studied. The results show that deposition times at 300 s NiCo-LDH sheets are anchored onto the surface of ZnO NRs, forming a three-dimensional (3D) interconnected thin-walled network structure. ZnO@NiCo-LDH300s electrode shows excellent electrochemical performance, such as areal capacitance of 667.3 mF cm−2 at 1 mA cm−2, and good cycle stability (86.78% capacitance retention after 2000 cycles), which may be attributed to the larger contact area and rich active sites between electrode provided by the NiCo-LDH grown on ZnO NRs. Furthermore, the asymmetric supercapacitor (ASC) is assembled with the ZnO@NiCo-LDH300s and active carbon (AC) as the electrodes, which exhibits an energy density of 0.044 mWh cm−2 at 1.17 mW cm−2.