Elevating supercapacitor performance: enhancing electrochemical efficiency with transition metal-doped polyaniline electrode

Official URL: https://dx.doi.org/10.1016/j.est.2023.110143

Polyaniline (PANI) stands out as a highly favored electrically conductive polymer, extensively investigated for its potential as an electrode material in the advancement of energy storage systems. Nevertheless, the practical utilization of PANI is hindered by its inadequate stability, posing limitations on its wider application. To address this issue, doping with carbon and carbon-based materials or transition metals is frequently employed. In this study, transition metals Ag+ and Fe3+ were doped into the of polyaniline PANI structure to enhance its surface area, conductivity, and electrochemical properties. The doping of Ag+ and Fe3+ into the PANI structure resulted in a significant increase of up to three times in the surface area and conductivity of PANI. Electro-Paramagnetic Resonance (EPR) spectra analysis showed a substantial change in the intensity value with Ag+ doping, while no significant alteration was observed in the g-factor values. Electrochemical analyses demonstrated that both Ag+ and Fe3+ doping improved the specific capacitance, energy density, and power density of PANI in both symmetric and asymmetric designs. Furthermore, the utilization of electron paramagnetic resonance (EPR) spectroscopy complemented the comprehensive electrochemical analysis by offering valuable insights into the defect structures present in the electrode materials.