Preparation and Modification of Polyacrylonitrile Microcellular Foam Films for Use as Electrodes in Supercapacitors

Abstract
Results obtained for polyacrylonitrile microcellular foam thin films deposited on carbon fibers are presented. It appears that surface modifications by CO2CO2 flow or water steam at high temperature lead to an increase of the film surface area as well as a proportional increase of capacitance. The films were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and the Brunauer-Emmett-Teller technique. Extensive electrochemical studies (cyclic voltammetry, ac impedance, galvanic cycles, and cycle life tests) were performed both in aqueous and organic media in order to evaluate their use as electrodes in a supercapacitor. The importance of the nature of the electrolyte was demonstrated using lithium perchlorate and tetraalkyl-based salts. The high performances of these activated materials were correlated both to their high surface area and their microporous distribution. © 2000 The Electrochemical Society. All rights reserved.