ABSTRACT Polyaniline‐fullerene (PANI‐C 60 ) composites containing 0.1%–0.5% (w/v) of C 60 were prepared via solution mixing, ultrasonication and drop‐casting techniques, and their charge transport, dielectric response and supercapacitor performance were correlated. Electrochemical properties were studied using cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy in a 0.5 M H 2 SO 4 electrolyte. A substantial improvement in charge‐storage performance of PANI‐C 60 composites was achieved when compared with PANI, and the optimum composition (0.25% (w/v) of C 60 in PANI (P25F)) delivered a high specific capacitance of 1425 F/g with an energy density of 49.72 Wh/kg and a power density of 502.78 W/kg at 2 A/g. The P25F electrode retained 89% of its capacitance and energy density even when the power density (W/kg) increased from 502 to 2276, and excellent durability was obtained with 93% capacitance retention after 3000 CV cycles. Dielectric studies revealed that the PANI‐C 60 composite exhibited significantly higher permittivity ( ε ′ ≈1.05 × 10 5 at 100 Hz) compared to pure PANI ( ε ′ ≈1.45 × 10 3 ), attributed to charge transfer complex formation and percolation effects. Temperature‐dependent charge transport of PANI‐C 60 composites followed a 3D variable range hopping mechanism in the composite, with a lower activation energy and improved charge transport parameters when compared to PANI. Field‐dependent conduction showed an Ohmic to space charge limited conduction (SCLC) transition ( m ≈1.48–2.1) with increasing C 60 content. Structural and morphological analyses (x‐ray diffraction, scanning electron microscopy, and high resolution‐transmission electron microscopy) confirmed composite formation and uniform C 60 dispersion in PANI matrix, supporting the observed dielectric and electrochemical superiority of the optimized PANI‐C 60 interface.
Mathew et al. (Thu,) studied this question.