Facile Synthesis of Pineapple Waste-Derived Carbon\nand Polyaniline Composite for High-Energy-Density Asymmetric Supercapacitors

Abstract

Pineapple\npeel has been chosen as a biowaste precursor to synthesize\nactivated carbon <i>via</i> KOH activation at 800 °C\n(PP-800). Further, the <i>in situ</i> chemical oxidation\nmethod was used to synthesize a composite of PP-800 with polyaniline\n(PANI). The successful formation of the composite (PP-800/PANI) was\nconfirmed <i>via</i> X-ray diffraction (XRD), and Raman\nand Fourier-transform infrared (FTIR) spectra. PP-800/PANI when tested\nin 1 M H₂SO₄ in a three-electrode configuration\nshowed a higher specific capacitance (377 F/g) than that of PP-800\n(328 F/g) and PANI (92.4 F/g) at 2 A/g. This is due to the significant\nenhancement in the diffusion contribution for PP-800/PANI (86.25%)\nthan that of PP-800 (61.7%) and PANI (49.9%) counterparts at 20 mV/s,\nwhich leads to the maximum utilization of the electrochemical surface\narea. Further, an asymmetrical supercapacitor device, PP-800/PANI//PP-800,\nwas fabricated, which delivered a high energy density of 51.2 Wh/kg\nat a decent power density of 380 W/kg with 90% cyclic stability after\n10,000 charge–discharge cycles.