Crosslinked polyaniline nanorods with improved electrochemical performance as electrode material for supercapacitors

Abstract

To improve the electrochemical performance of polyaniline (PANI), crosslinked polyaniline nanorods (CPANI) were prepared via the chemical oxidative copolymerization of aniline with p-phenylenediamine (PPDA) and triphenylamine (TPA). Their morphology and structure were compared with polyaniline (PANI) via transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD) and thermogravimetric analysis (TGA) techniques. CPANI nanorods exhibited an improved electrical conductivity (33.3 S cm⁻¹) in comparison with PANI (4.26 S cm⁻¹). Its electrochemical performance was studied by galvanostatic charge–discharge (GCD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests. CPANI nanorods exhibited a maximum specific capacitance of 455.1 F g⁻¹ at a scan rate of 1 mV s⁻¹ in a 1.0 mol L⁻¹ H₂SO₄ electrolyte, which is much higher than that of PANI (286.7 F g⁻¹). Note that the cycling stability of CPANI electrode was improved significantly by chemical crosslinking, and showed higher capacitance retention after 1300 cycles.