Estimation of Equilibrium Capacitance of Polyaniline Films Using Step Voltammetry
DSpace at IIT Bombay
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Title |
Estimation of Equilibrium Capacitance of Polyaniline Films Using Step Voltammetry
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Creator |
CONTRACTOR, AQ
JUVEKAR, VA |
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Subject |
CONDUCTING POLYMERS
ELECTROCHEMICAL PROPERTIES RECHARGEABLE BATTERY CATHODE MATERIAL COMPOSITE STORAGE SUPERCAPACITOR NANOPARTICLES PERFORMANCE ELECTRODES |
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Description |
The equilibrium charge storage characteristic of polyaniline films has been determined using step voltammetry technique. The step coulogram (plot of charge stored versus potential) consists of five distinct regions, which correspond to the different energy bands exhibited by the film, in keeping with Raman and ESR spectroscopy data. The coulogram is piecewise linear, with constant capacitance in each band. Effect of the type and concentration of the acid on the equilibrium capacitances of the bands has been studied. The polaron band has the highest capacitance, followed by the bipolaron band and then the polaron lattice band. The charge stored at a given potential is found to be proportional to film mass. The film needs to be polarized to a threshold charge before faradaic charging begins. This faradaic threshold is independent of the type and concentration of the acids. The step coulogram is compared with the sweep coulogram obtained from linear sweep voltammetry. At low sweep rates, the sweep coulogram also exhibits five distinct bands. However, with increase in the sweep rate, the bands progressively reduce in number. The capacitance of the polaron band decreases linearly with square root of sweep rate and attains the equilibrium capacitance at zero sweep rate. (C) The Author(s) 2015. Published by ECS. All rights reserved.
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Publisher |
ELECTROCHEMICAL SOC INC
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Date |
2016-01-15T09:57:43Z
2016-01-15T09:57:43Z 2015 |
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Type |
Article
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Identifier |
JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 162(7)A1175-A1181
0013-4651 1945-7111 http://dx.doi.org/10.1149/2.0151507jes http://dspace.library.iitb.ac.in/jspui/handle/100/18310 |
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Language |
en
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