Nanosheet-Assembled\nNiO Microstructures for High-Performance\nSupercapacitors

Abstract

Nanosheet-assembled NiO microstructures\nhave been synthesized via\na hydrothermal method. The presence of anionic surfactant in the fabrication\nprocess initiates the formation of lamellar micelles and a self-assembling\nprocess. This leads to the formation of NiO nanosheets and organizes\nit into microstructures. The effect of preparation temperature on\nthe morphological, structural, and electrochemical properties and\nstability upon continuous charge/discharge cycles has been examined\nfor supercapacitor applications. Electrochemical analysis demonstrated\nthat NiO nanosheets prepared at 160 °C are capable of delivering\na specific capacitance of 989 F g^–1 at a scan rate\nof 3 mV s^–1 for the potential window of 0–0.6\nV. The nanosheets exhibit excellent capacity retention, 97% retention\nafter 1000 continuous charge/discharge cycles, and an energy density\nof 49.45 W h kg^–1.