Design of FeCo2S4@Ni(OH)2 core-shell hollow nanotube arrays on carbon paper for ultra-high capacitance in supercapacitors. (20th July 2020)

• Record Type: Journal Article
• Authors: Zhou, Saiyu; Liu, Yu; Yan, Ming; Sun, Lin; Luo, Bifu; Yang, Qingjun; Shi, Weidong
• Is Part Of: Electrochimica acta. Volume 349(2020)
• Publication Date: 2020-07-20
• Subjects: Electrodeposition -- Core-shell -- Hollow nanotube -- Asymmetry supercapacitor; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2020.136337
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: In this paper, we design a novel FeCo2 S4 @Ni(OH)2 core-shell hollow nanotube arrays on carbon paper for superior capacitance of supercapacitors. FeCo2 S4 hollow nanotube arrays vertically grow on carbon paper via hydrothermal reaction served as a "core" to shorten the ion transport path, Ni(OH)2 nanosheets modified on the hollow nanotube arrays based on constant voltage electrodeposition reveal outstanding pseudocapacitance characteristic. The ultrathin Ni(OH)2 nanosheets act as a "shell" layered to expand the specific surface area, effectively increasing the active sites of the faraday reaction. The subtle heterogeneous synergistic effects significantly improve their electrochemical performance. The unique core-shell structure of FeCo2 S4 @Ni(OH)2 displays a superior capacity of 239.72 mA h g −1 at 1 A g −1, even at 8 A g −1 still has a capacity of 128.0 mA h g −1, indicating the excellent rate performance. Significantly, the asymmetric supercapacitor assembled by the FeCo2 S4 @Ni(OH)2 nanoarrays positive electrode and activated carbon (AC) negative electrode exhibits superior electrochemical performance with ultra-high energy density (55.33 Wh Kg −1 at 800 W kg −1 ) and power density (8000 W kg −1 at 15.78 Wh Kg −1 ). After 10000 charge-discharge cycles, the device still has capacitance retention of 93.8%. Therefore, FeCo2 S4 @Ni(OH)2 nanoarrays can be widely used in high-performance supercapacitors as potential and promising electrode materials. Graphical abstract: Composition of FeCo2 S4 @Ni(OH)2 //AC two-electrode supercapacitor with ultra-high electrochemical performance (55.33 Wh Kg −1 at 800 W kg −1 ) and still retains 93.8% capacitance after 10, 000 cycles，Charging to 3.2 V in tens of seconds, the device can light up the circular blue LED for a period of time. Image 1