title: High-performance supercapacitor electrode based on the unique ZnO@Co₃O4₄ core/shell heterostructures on nickel foam.
abstract: Currently, tremendous attention has been paid to the rational design and synthesis of unique core/shell heterostructures for high-performance supercapacitors. In this work, the unique ZnO@Co3O4 core/shell heterostructures on nickel foam are successfully synthesized through a facile and cost-effective hydrothermal method combined with a short post annealing treatment. Mesoporous Co3O4 nanowires are multidirectional growing on the rhombus-like ZnO nanorods. In addition, the growth mechanism for such unique core/shell heterostructures is also proposed. Supercapacitor electrodes based on the ZnO@Co3O4 and Co3O4 heterostructures on nickel foam are thoroughly characterized. The ZnO@Co3O4 electrode exhibits high capacitance of 1.72 F cm(-2) (857.7 F g(-1)) at a current density of 1 A g(-1), which is higher than that of the Co3O4 electrode. Impressively, the capacitance of the ZnO@Co3O4 electrode increases gradually from 1.29 to 1.66 F cm(-2) (830.8 F g(-1)) after 6000 cycles at a high current density of 6 A g(-1), indicating good long-term cycling stability. These results indicate the unique ZnO@Co3O4 electrode would be a promising electrode for high-performance supercapacitor applications.
authors.affiliation: Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University , Xiamen 361000, People's Republic of China.
authors.forename: Daoping
authors.initials: D
authors.lastname: Cai
authors.forename: Hui
authors.initials: H
authors.lastname: Huang
authors.forename: Dandan
authors.initials: D
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Lingling
authors.initials: L
authors.lastname: Wang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Qiuhong
authors.initials: Q
authors.lastname: Li
authors.forename: Taihong
authors.initials: T
authors.lastname: Wang
keywords: binder-free; cobalt oxides; core/shell; electrode material; supercapacitor