Carbon-coated Hierarchical Ni–Mn Layered Double Hydroxide Nanoarrays on Ni Foam for Flexible High-capacitance Supercapacitors. (20th September 2016)

• Record Type: Journal Article
• Authors: Chen, Hongyan; Ai, Yani; Liu, Fan; Chang, Xing; Xue, Yuan; Huang, Qi; Wang, Chi; Lin, Hualin; Han, Sheng
• Is Part Of: Electrochimica acta. Volume 213(2016)
• Page Start: 55
• Page End: 65
• Publication Date: 2016-09-20
• Subjects: Ni-Mn layered double hydroxide -- glucose -- hierarchical nanoarrays -- asymmetric supercapacitor; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2016.06.038
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Highlights: We had established 3D hierarchical configuration successfully via facile two-step hydrothermal reation with flexible 3D Ni foam substrate, vertical aligned LDH nanosheet and carbon shell. Our carbon coated LDH growing on Ni foam materials eventually improved the electrochemical performance when act as the electrode materials for supercapacitor. The specific capacitance is up to 1916 F g −1 with the current density of 0.5 A g −1 and there were still 79.5% retention at 10 A g −1 . What's more, the cycling stability was more excellent compared with other relevant works[38, 41, 46] . In our work, there was still 91% retention after 5000 charge-discharge cycles at 2 A g −1 . We found out that all the Ni-Mn LDH, 3D nickel foam and carbon shell provided synergistic effects of excellent pseudocapacitive properties, high conductivity and cycling stability. We have well controlled the mass of coated carbon and first identified the most optimal content of coated carbon in ultimate material. Abstract: Hierarchical nanoarchitecture and composition can offer preponderances for enhancing pseudocapacitor performances. This paper reports on the three-dimensional hierarchical carbon-coated Ni–Mn layered double hydroxide on nickel foam (LNC) electrode material prepared via a facile two-step hydrothermal reaction. The resulting performance of the LNC composite material has high specific capacitance (1916 F g −1 ) and good cycling stability (91% retention after 5000 charge–discharge cycles). Moreover, the material can be directly used as an integrated flexible electrode with excellent rate capability (79.5% retention at 10 A g −1 ), which is significant in practical applications and large-scale syntheses. Furthermore, the LNC materials acting as a positive electrode for the asymmetric supercapacitor also exhibit high specific capacitance of 120.67 F g −1 at 0.5 A g −1 and excellent cycling stability with 84.2% capacitance retention after 5000 cycles at a current density of 5 A g −1 .