PANI/Au/Fe3O4 nanocomposite materials for high performance energy storage

Abstract In this work new energy storage components were prepared depositing films made of polyaniline (PANI) modified with gold/magnetite nanoparticles on flexible graphite foils. Three types of composite materials termed PANI/Fe3O4, PANI/Au/Fe3O4 and PANI/Au/Fe3O4@Yne (where @Yne is a propynylcarbamate group) were obtained by electrosynthesis. Galvanostatic charge-discharge (CD) and impedance tests (EIS) were performed to verify their efficiency in charge storage properties: for the gold-containing electrodes PANI/Au/Fe3O4 and PANI/Au/Fe3O4@Yne areal capacities values of 45.6 and 46.5 mAh cm−2 were found in 0.5 M H2SO4 + 0.1 M LiClO4 electrolyte solution at a current density of 0.5 mA cm−2. These values are twofold higher than those found for PANI/Fe3O4 electrodes and fourfold greater than those for PANI alone (11.0 mAh cm−2). In turn PANI/Au/Fe3O4 and PANI/Au/Fe3O4@Yne were employed to assemble gel-state symmetric devices. CD, EIS and longtime resistance tests were made on the new devices that displayed an areal capacities of 100.0 mAh cm−2 for PANI/Au/Fe3O4 and 73.6 mAh cm−2 PANI/Au/Fe3O4@Yne respectively. To our knowledge this is the first time that AuNP–modified magnetite nanoparticles are used in energy storage devices preparation.