Síntese e caracterização eletroquímica de compósitos de HTL/PAni para possível aplicação em supercapacitores

Abstract

The energy storage and conversion devices, specially supercapacitors, have stood out by fast storage capacity (low-time discharge) and good cycle stability, when compared to other devices. In this contexto, the association of lamellar triple hydroxides (LTHs), which are low cost, easy to obtain and have a high surface area, with conductive polymers favors the system's charge transport, making it a promising material for application in energy storage devices. So, this work was based on the LTH [Co-Al-Fe-Cl] synthesis, using the co-precipitation method at constant pH, with subsequent LTH [Co-Al-Fe-Cl]/PAni composite synthesis for application as electrodes in asymmetric supercapacitors. The X-ray diffractograms of LTH [Co-Al-Fe-Cl] indicated hydrotalcite chacacteristic peaks, which are indexed to the hexagonal structure with rhombohedral symmetry (space group R-3m). The SEM image showed overlapping plates, in addition to the heterogeneous arrangement and the presence of nanometric materials on the material’s surface. For application as electrodes in asymmetric supercapacitors in aqueous solution of Na2SO4 (1 mol/L), the GE/LTH/PAni│Na2SO4│AC/GE device presented a faradaic contribution to the capacitive process, which resulted in higher values of current density, specific capacitance of 499.50 F g-1, energy density of 69.38 Wh kg-1 and specific power of 2.50kW kg-1, promising values for application as electrodes in asymmetric supercapacitors.