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.