Electrochemical characteristics of polyaniline synthesized in the presence of ferrocenesulfonic acid

Ferrocenesulfonic acid plays an important role in increasing the electrochemical polymerization rate of aniline. Polyaniline (PAnFc) prepared in the presence of ferrocenesulfonic acid has a rather high electrochemical activity at pH greater than or equal to 4 compared with polyaniline (PAn) prepared in the absence of ferrocenesulfonic acid. The cyclic voltammograms of both PAn and PAnFc in 0.5 mol dm(-3) Na2SO4 with pH greater than or equal to 4 show that the low electrochemical activities are caused by the low electron transfer ability of both polymers themselves. The study on the temperature dependence of the cyclic voltammograms at pH 5.0 indicates that there are two anodic peaks and two cathodic peaks for PAnFc, however, there are only one anodic peak and one cathodic peak for PAn at the temperature <60 degreesC in the potential range between -0.2 and 0.6 V (vs. SCE). Based on the results from the constant current discharge of polyaniline batteries, the capacity density and energy density of PAnFc are 124.0 A h kg(-1) and 126.2 W h kg(-1), respectively, which are 1.58 and 1.47 times higher than the capacity density and energy density, respectively, of PAn. The FTIR spectrum of PAnFc is presented here. (C) 2002 Elsevier Science B.V All rights reserved.