High-Performance Gel Electrolyte Asymmetric Supercapacitor Based on Polypyrrole-Tungsten Disulfide Nanocomposite

Abstract

In this work, a polypyrrole-tungsten disulfide (PPy-WS2) nanocomposite was synthesized through oxidative polymerization and evaluated as an electrode material for supercapacitors. Structural and morphological analyses confirmed the successful integration of WS2 within the PPy matrix. Electrochemical testing revealed a high specific capacitance of 816 F g-1 at a scan rate of 1 mVs-1, together with excellent cycling durability. To further assess device-level performance, an asymmetric supercapacitor was assembled using the PPy-WS2 nanocomposite as the positive electrode, activated carbon as the negative electrode, and a PVA/KOH gel electrolyte. The device achieved an energy density of 41.6 Wh kg-1 and a power density of 1500 W kg-1, while maintaining 105% of its capacitance after 2500 charge-discharge cycles. The prototype was also able to power a light-emitting diode, highlighting its practical potential. These findings demonstrate that the synergistic coupling between polypyrrole and tungsten disulfide substantially improves electrochemical behaviour, positioning the PPy-WS2 nanocomposite as a promising candidate for advanced energy storage applications.