Modulating Electrochemical Performance of Interfacially Polymerized, MoS₂ Decorated Polyaniline Composites for Electrochemical Capacitor Applications

Among the transition metal dichalcogenides, molybdenum disulfide (MoS2), a graphene analogue, is the most sought after 2D material for energy storage devices. Electrical conductivity of the thermodynamically stable, semiconducting 2H MoS2 phase can be further enhanced by the incorporation of conducting polymers. Herein, we synthesize the MoS2–PANI nanocomposite with increased crystallinity through an interfacial polymerization route where the growth of HCl doped polyaniline fibers through the MoS2 sheets developed an intrinsic strong π back-donation between the Mo and the N of the polyaniline fibers. This characteristic π bond has enhanced the conductivity as well as the intrinsic pseudocapacitance by an additional redox electron exchange occurring at the Mo centers. The optimized 1 wt % MoS2 decorated PANI nanosheets showed a high capacitance of 657.5 F/g at 1.5 A/g, and the corresponding symmetric and asymmetric supercapacitor cells delivered a capacitance of 424 F/g and 335 F/g at 0.5 A/g, respectively. The potential window was increased to 1.5 V in the asymmetric configuration, leading to an enhanced energy density of 104.9 Wh/kg and a power density of 937.9 W/kg. The work highlights the beneficial effects of incorporating MoS2 in polyaniline for improved capacitance and provides a feasible approach to modulate the electrochemical performance of PANI-based materials for energy storage.