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Asymmetric supercapacitors based on β-Ni(OH)2 nanosheets and activated carbon with high energy density.
- Source :
-
Journal of Power Sources . Jan2014, Vol. 246, p371-376. 6p. - Publication Year :
- 2014
-
Abstract
- Abstract: Ni(OH)2 nanosheets are directly grown on nickel foam by a simple template-free growth process. Their microstructure and surface morphology are studied by X-ray diffraction spectroscopy and scanning electron microscopy. The XRD and SEM results show that Ni(OH)2 has a β-phase structure and covers the nickel foam skeleton with nanosheets. This β-Ni(OH)2/Ni-foam electrode exhibits a high specific electric quantity of 790.3 C g−1 approaching the theoretical value (1040.6 C g−1) and high electrochemical activity. Asymmetric supercapacitor has been fabricated successfully using β-Ni(OH)2/Ni-foam nanosheets as positive electrode and activated carbon as negative electrode in a KOH aqueous electrolyte. The electrochemical capacitances of this supercapacitor are investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. An asymmetric supercapacitor AC/6 mol L−1 KOH/β-Ni(OH)2/Ni-foam could be cycled reversibly in the high-voltage region of 0–1.6 V and displays intriguing performances with a specific capacitance of 105.8 F g−1 and high energy density of 36.2 W h kg−1. Importantly, this asymmetric supercapacitor device exhibits an excellent long cycle life along with 92% specific capacitance retained after 1000 cycles. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 03787753
- Volume :
- 246
- Database :
- Academic Search Index
- Journal :
- Journal of Power Sources
- Publication Type :
- Academic Journal
- Accession number :
- 90523699
- Full Text :
- https://doi.org/10.1016/j.jpowsour.2013.07.105