Polyaniline and polyaniline-carbon black nanostructures as electrochemical capacitor electrode materials

Polyaniline (PANI) and polyaniline-carbon black (PANI-CB) nanostructures were developed and their behavior in relation to supercapacitors properties was tested. Different nanostructures were prepared by a simple chemical method of self-organization. SEM and TEM images revealed PANI nanotubes of ca. 95 nm in diameter; nanoparticles, nanobelts, nanosheets and/or nanotubes could be recognized in PANI-CB nanocomposites as a result of the use of CB particles with and without chemical pretreatment, CBf and CBnf, respectively. From EDS, XRD, UV-Vis and FTIR characterization techniques, the development of the various nanostructures was attributed to the chemical polymerization process that provoked a doped PANI state and hydrogen links that stabilized the changes in the structures. The resulted morphologies influenced the capacitance, specific power and specific energy values. PANI-CBf nanocomposites displayed improved capacitive properties in H2SO4 solutions, namely 1486 F g−1 at 2 A g−1. The charge-discharge tests indicated that the loss of capacitance during the charge/discharge cycles was lower than 18% for the checked materials.