Abstract
Electrode materials based on iron doped polyaniline (Fe-PANI) over the surface of sulfonated multi-walled carbon nanotubes (s-MCNTs) followed by freeze-drying treatment (FD-Fe-PANI@s-MCNTs) are dedicated for high performance electrochemical energy storage applications. The structure, morphology and thermal properties of the studied electrode samples are measured with different characterizing techniques. The N-2 sorption isotherm for (FD-Fe-PANI@s-MCNTs) shows high specific surface area 397.79 m(2) g(-1) calculated by Brunauer-Emmett-Teller (BET) method after the freeze-drying treatment.The electrochemical properties of the electrode samples are assessed by cyclic voltammetry and galvanostatic charge/discharge testes in the 1 M H2SO4 aqueous electrolyte. The (FD-Fe-PANI@s-MCNTs) electrode with this high surface area shows high specific capacitance of 2105.64 F g(-1) at 1 A g(-1). The symmetric solid-state supercapacitor device (SCs) based on (FD-Fe-PANI@s-MCNTs) electrode gave a specific capacitance of 776.85 F g(-1) at 1 A g(-1), energy density 13.55 Wh kg(-1), power density 177.50 W kg(-1) and exhibit rate capability (approximate to 59% retention at 20 A g(-1)). Furthermore, the symmetric supercapacitor device shows good cycling stability (91.6%) after 500 cycles at a scan rate 200 mV s(-1), suggesting the potential application of (FD-Fe-PANI@s-MCNTs) for energy storage devices.