Nickel cobalt hydroxide/reduced graphene oxide/carbon nanotubes for high performance aqueous asymmetric supercapacitors

• Published in: Journal of alloys and compounds 2018-07, Vol.753, p.525-531
• Main Authors: Hou, Zhi-Qiang, Tian, Feng-Shou, Gao, Yong-Ping, Wu, Wen, Yang, Li-Xia, Jia, Xiao-Lu, Huang, Ke-Jing
• Format: Article
• Language: English
• Subjects: Activated carbon; Asymmetric supercapacitor; Asymmetry; Carbon; Carbon nanotubes; Electrodes; Energy storage; Enhanced performance; Flux density; Graphene; Metal oxides; Nanostructured materials; Nanotubes; Nickel; Nickel cobalt hydroxide/reduced graphene oxide/carbon nanotubes; Supercapacitors
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2018.04.245

In this work, the hybrid nanostructures composed of Ni-Co hydroxide, reduced graphene oxide (rGO) and carbon nanotubes (CNTs) are successfully synthesized and used as a self-supported electrode for supercapacitors. It is found that the hybrid shows a big capacity of 1093 F g−1, excellent rate capability, and superior cycle life (100% capacity maintain after 5000 cycles). One asymmetric supercapacitor (ASC) is developed using Ni-Co hydroxide/rGO/CNTs as positive material and active carbon as negative material. This ASC displays a maximum energy density of 34.7 Wh kg−1 at a high power density of 1.55 kW kg−1 and still keeps 20.7 Wh kg−1 at 15.5 kW kg−1. Moreover, it displays remarkable cycle life with 112.8% capacity retention after 10000 cycles. Such asymmetric supercapacitor demonstrates great potential for practical application in energy storage devices. •Ni-Co hydroxide/rGO/CNTs hybrids are prepared by the vacuum filtration method.•Asymmetric supercapacitor is prepared with as-prepared materials and active carbon.•The supercapacitor shows high specific capacitance and excellent cycling stability.