2-methylimidazole-derived Ni-Co layered double hydroxide nanosheets as high rate capability and high energy density storage material in hybrid supercapacitors

Wang, Teng and Zhang, Shengli and Yan, Xingbin and Lyu, Miaoqiang and Wang, Lianzhou and Bell, John and Wang, Hongxia (2017) 2-methylimidazole-derived Ni-Co layered double hydroxide nanosheets as high rate capability and high energy density storage material in hybrid supercapacitors. ACS Applied Materials and Interfaces, 9 (18). pp. 15510-15524. ISSN 1944-8244


Abstract

A new method based on one-step solvothermal reaction is demonstrated to synthesize ultrathin Ni–Co layered double hydroxide (LDH) nanosheets, which grow directly on a flexible carbon fiber cloth (NiCo-LDH/CFC). Through using 2-methylimidazole as complex and methanol as solvent, the as-prepared NiCo-LDH/CFC shows a (003) facet preferential growth and an expanded interlayer spacing structure, resulting in a unique 3D porous nanostructure with a thickness of nanosheets of around 5–7 nm that shows high energy storage performance. By controlling the ratio of Ni/Co = 4:1 in the precursor solution, the electrode shows a specific capacitance of 2762.7 F g–1 (1243.2 C g–1) at a current density of 1 A g–1. Nevertheless, the optimal composition is obtained with Ni/Co = 1:1, which produces a specific capacitance of 2242.9 F g–1 (1009.3 C g–1) at 1 A g–1 and shows an excellent rate capability with 61% of the original capacitance being retained at a current density of 60 A g–1. The hybrid supercapacitor (HSC) based on the NiCo-LDH/CFC exhibits a maximum energy density of 59.2 Wh kg–1 and power densities of 34 kW kg–1, respectively. Long-term stability test shows that 82% of the original capacitance of the HSC remains after 5000 cycles. Importantly, the electrochemical performance of the solid-state flexible supercapacitors based on the prepared NiCo-LDH/CFC electrode showed a negligible change when the device was bent up to 180°. The performance of synthesized NiCo-LDH/CFC indicates the great potential of the material for delivering both high energy density and high power density in energy storage devices.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: Current - Research and Innovation Division (12 Jul 2012 -)
Faculty/School / Institute/Centre: Current - Research and Innovation Division (12 Jul 2012 -)
Date Deposited: 18 Sep 2020 00:24
Last Modified: 24 Sep 2020 06:17
Uncontrolled Keywords: hybrid supercapacitor; NiCo-LDH nanosheets; binder-free; flexible; carbon fiber cloth; atomic thickness
Fields of Research (2008): 03 Chemical Sciences > 0399 Other Chemical Sciences > 039999 Chemical Sciences not elsewhere classified
Identification Number or DOI: https://doi.org/10.1021/acsami.7b02987
URI: http://eprints.usq.edu.au/id/eprint/39390

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