Preparation of NiO decorated CNT/ZnO core-shell hybrid nanocomposites with the aid of ultrasonication for enhancing the performance of hybrid supercapacitors

• Published in: Ultrasonics sonochemistry Vol. 71; p. 105374
• Main Authors: Jayababu, Nagabandi, Jo, Seungju, Kim, Youngsu, Kim, Daewon
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2021; Elsevier
• Subjects: Carbon nanotubes; Core-shell nanostructures; Hybrid supercapacitor; NiO decoration; Original; Ultrasonication; ZnO; Carbon nanotubes; Ultrasonication; Core-shell nanostructures; ZnO; NiO decoration; Hybrid supercapacitor
• ISSN: 1350-4177; 1873-2828
• DOI: 10.1016/j.ultsonch.2020.105374

Supercapacitor (SC) electrodes fabricated with the combination of carbon nanotubes (CNTs) and metal oxides are showing remarkable advancements in the electrochemical properties. Herein, NiO decorated CNT/ZnO core-shell hybrid nanocomposites (CNT/ZnO/NiO HNCs) are facilely synthesized by a two-step solution-based technique for the utilization in hybrid supercapacitors. Benefitting from the synergistic advantages of three materials, the CNT/ZnO/NiO HNCs based electrode has evinced superior areal capacity of ~67 µAh cm−2 at a current density of 3 mA cm−2 with an exceptional cycling stability of 112% even after 3000 cycles of continuous operation. Highly conductive CNTs and electrochemically active ZnO contribute to the performance enhancement. Moreover, the decoration of NiO on the surface of CNT/ZnO core-shell increases the electro active sites and stimulates the faster redox reactions which play a vital role in augmenting the electrochemical properties. Making the use of high areal capacity and ultra-long stability, a hybrid supercapacitor (HSC) was assembled with CNT/ZnO/NiO HNCs coated nickel foam (CNT/ZnO/NiO HNCs/NF) as positive electrode and CNTs coated NF as negative electrode. The fabricated HSC delivered an areal capacitance of 287 mF cm−2 with high areal energy density (67 µWh cm−2) and power density (16.25 mW cm−2). The combination of battery type CNT/ZnO/NiO HNCs/NF and EDLC type CNT/NF helped in holding the capacity for a long period of time. Thus, the systematic assembly of CNTs and ZnO along with the NiO decoration enlarges the application window with its high rate electrochemical properties.