Improved capacitive performance of conducting polymer with incorporation of biomass derived activated carbon for supercapacitors

Abstract

Nanocomposites that integrate electrostatic charge accumulation and faradic reaction mechanisms hold significant potential as high-performance supercapacitor electrodes for electrochemical energy storage. However, the development of low-cost carbon composites derived from renewable resources remains challenging. Herein, we demonstrate two different conducting polymers such as polyaniline (PA) and polypyrrole (PP) with incorporation of biomass-derived activated carbon from Strychnos Potatorum shells (SPAC) through in-situ polymerization. The SPAC was prepared through pre‑carbonization followed by a physical activation method. The structural defects of the as-synthesized polymer composites were characterized thoroughly by various physicochemical techniques including Fourier transform infrared (FT-IR), Raman, X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), and Field emission scanning electron microscopy (FE-SEM). Further, the PA and PP composite electrode materials were examined by electrochemical methods such as cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) techniques. Under the optimal conditions, the high specific capacitance was observed in PA@SPAC30 (214 F g⁻¹) at 1.0 A g⁻¹ compared to other composites such as PA@SPAC5 (35.2 F g⁻¹), PA@SPAC10 (75.2 F g⁻¹), PA@SPAC15 (101.4 F g⁻¹), PA@SPAC50 (175.4, F g⁻¹) and neat PA (168 F g⁻¹), respectively. The specific capacitance of PP@SPAC5, PP@SPAC10, PP@SPAC15, PP@SPAC30, PP@SPAC50, and neat PP composites series, are 37.5, 76.4, 202.8, 144, 139.5, and 146 F g⁻¹ respectively, at 1.0 A g⁻¹. The rapid GCD characteristics of PA@SPAC30 and PP@SPAC15 are due to their excellent porosity and well-structured architectural morphology, which facilitate short ion diffusion paths and unrestricted access during GCD cycles. The specific capacitance are remains 94.55 % and 95.8 % of initial capacitance demonstrating that the PA@SPAC30 and PP@SPAC15 electrodes exhibit remarkable cyclability over 5000 GCD cycles.