Kalpana, D. and Omkumar, K.S. and Sureshkumar, S. and Renganathan, N.G. (2006) A novel high power symmetric ZnO/carbon aerogel composite electrode for electrochemical supercapacitor. Electrochimica Acta, 52 (3). pp. 1309-1315. ISSN 0013-4686

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Abstract

We present, for the first time, a new material of symmetric electrochemical supercapacitor in which zinc oxide (ZnO) with carbon aerogel (CA) was used as active material. Physical properties of ZnO/CA composite were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that ZnO has single hexagonal structure and the grain size increases with increase of ZnO compository. The result of cyclic voltammetry indicates that the specific capacitance of ZnO/CA composite in 6M KOH electrolyte was approximately 25 F/g at 10 mV/s for 2:1 composition. AC impedance analysis reveals that ZnO with carbon aerogel powder enhanced the conductivity by reducing the internal resistance. Galvanostatic charge/discharge measurements were done at various current densities, namely 25, 50, 75, and 100 mA/cm2. It was found that the cells have excellent electrochemical reversibility and capacitive characteristics in KOH electrolyte. The maximum capacitance of the ZnO/CA supercapacitor was 500 F/g at 100 mA/cm2. It has been observed that the specific capacitance is constant up to 500 cycles at all current densities, which implies that the dendrite formation was controlled.

Item Type: Article
Uncontrolled Keywords: Supercapacitor; Zinc oxide; Specific capacitance; Carbon aerogel; Dendrites
Subjects: Electrochemical Power Sources
Divisions: UNSPECIFIED
Depositing User: ttbdu cecri
Date Deposited: 06 Apr 2012 15:32
Last Modified: 06 Apr 2012 15:32
URI: http://cecri.csircentral.net/id/eprint/607

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