Polypyrrole decorated on irregular SnSe particles: A high energy density and stable durability for asymmetric supercapacitor applications

This work reported the tin selenide (SnSe), polypyrrole (PPy), and their nanocomposite with different contents, e.g., SnSe-10%PPy, and SnSe-30%PPy and examined their electrochemical performance for supercapacitor (SCs) applications. XRD and Raman's analysis confirmed the crystalline nature and phase purity with the adequate formation of the samples. The EDS mapping results confirm the structural homogeneity of the samples in the composite matrix, while the EDX spectrum of the samples reveals the purity and the adequate formation of the compounds. The morphological investigation reveals that the SnSe and PPy are composed of irregular particle morphology covered with thin sheets, forming highly conductive pathways for the diffusion of electrolyte ions to facilitate faradaic reactions. The detailed electrochemical investigation demonstrated that the SnSe-30%PPy nanocomposite electrode outperforms the pure SnSe, and SnSe-10%PPy electrodes with a maximum charge storage capability owing to their lower ohmic resistance during fast faradaic reactions. A hybrid-type asymmetric SC was assembled using activated carbon (AC) as an anode and the SnSe-30%PPy nanocomposite as the cathode in a sandwich-type configuration in an aqueous solution. A 1.7 V SnSe-30%PPy||AC asymmetric SCs was built that simultaneously achieved a high capacitance of 140 F/g and realized a maximum energy density of 56.19 Wh/kg at the power density of 850 W/kg at a low discharge current of 1 A/g with great cyclic stability of 84.7 % after 10,000 cycles, demonstrating their promising prospect towards future alternative energy storage devices. Our work demonstrated that pairing polymers with chalcogenides seems to be one of the promising research directions to upgrade the poor charge storage properties of polymers and prevent structural collapse efficiently.