title: 3D carbon/cobalt-nickel mixed-oxide hybrid nanostructured arrays for asymmetric supercapacitors.
abstract: The electrochemical performance of supercapacitors relies not only on the exploitation of high-capacity active materials, but also on the rational design of superior electrode architectures. Herein, a novel supercapacitor electrode comprising 3D hierarchical mixed-oxide nanostructured arrays (NAs) of C/CoNi3 O4 is reported. The network-like C/CoNi3 O4 NAs exhibit a relatively high specific surface area; it is fabricated from ultra-robust Co-Ni hydroxide carbonate precursors through glucose-coating and calcination processes. Thanks to their interconnected three-dimensionally arrayed architecture and mesoporous nature, the C/CoNi3 O4 NA electrode exhibits a large specific capacitance of 1299 F/g and a superior rate performance, demonstrating 78% capacity retention even when the discharge current jumps by 100 times. An optimized asymmetric supercapacitor with the C/CoNi3 O4 NAs as the positive electrode is fabricated. This asymmetric supercapacitor can reversibly cycle at a high potential of 1.8 V, showing excellent cycling durability and also enabling a remarkable power density of ∼13 kW/kg with a high energy density of ∼19.2 W·h/kg. Two such supercapacitors linked in series can simultaneously power four distinct light-emitting diode indicators; they can also drive the motor of remote-controlled model planes. This work not only presents the potential of C/CoNi3 O4 NAs in thin-film supercapacitor applications, but it also demonstrates the superiority of electrodes with such a 3D hierarchical architecture.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore; School of Materials Science and Engineering, Nanyang Technological University, 639798, Singapore.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Zhu
authors.forename: Jian
authors.initials: J
authors.lastname: Jiang
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Sun
authors.forename: Jingshan
authors.initials: J
authors.lastname: Luo
authors.forename: Zhanxi
authors.initials: Z
authors.lastname: Fan
authors.forename: Xintang
authors.initials: X
authors.lastname: Huang
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Ting
authors.initials: T
authors.lastname: Yu
keywords: asymmetric supercapacitors; cobalt; electrodes; hierarchical materials; nickel; oxides