PPy/PANI@MoS₂ Composites with a Dual-Channel Architecture for Advanced Asymmetric Supercapacitors

Abstract

While asymmetric supercapacitors (ASCs) have huge potential as efficient, durable, and cost-effective energy storage devices, they fail to meet expectations because of the unoptimized architecture and composition of their electrode materials. Herein, PPy/PANI@MoS 2 (PPMS) ternary composites with a dual-channel structure are obtained by facile hydrothermal and in situ polymerization methods. These dual conductive channels synergistically improve the electrode's electrical conductivity, facilitate ion diffusion, enlarge the interlayer distance, and increase the accessible surface area. Taking advantage of such a favorable architecture, PPMS composites exhibit outstanding electrochemical properties, including a huge specific capacitance (1171 F g −1 at 1 A g −1 ) and rate capability (861 F g −1 at 20 A g −1 ) in three-electrode systems. Based on charge storage mechanism analyses, we demonstrate that the kinetic behavior of PPMS electrodes is dominated by the surface capacitance (95.9% at 100 mV s −1 ). Besides, PPMS-based ASCs (PPMS//activated carbon) operate in a broad voltage window (1.8 V), delivering an ultrahigh energy density of 93.4 Wh kg −1 at a power density of 884.8 W kg −1 . They also show a superior cycling stability of 90.4% and a remarkable Coulombic efficiency of 99.2% for 10,000 cycles. This work affords an inspiration for rational structural optimization of PANI-based electrode materials with great prospects in the development of next-generation high energy density ASCs.