Banyan wood-derived activated carbon and binder-free Co9S8/NF@PPy hierarchical flower-like electrodes: Na+ and K+ electrolytes based solid-state asymmetric supercapacitor

Abstract

Supercapacitors require immediate electrode materials with outstanding performance. Here, a heterostructure Co9S8@PPy supported on conductive Ni foam (Co9S8/NF@PPy) is created utilizing hydrothermal and chemical polymerization techniques. The Co9S8/NF@PPy electrode exhibits an exceptional specific capacitance of 1485C g−1 and 1936C g−1 at a current density of 2 A g−1, respectively, using various Na2So4 and KOH electrolytes. The improved electrochemical efficiency could be attributed to the superior structural properties, the numerous active sites, the abundance of redox reactions, the strong synergistic effect in the heterogeneous conducting polymer composition, and the good conductivity resulting from the NF and the Co9S8/NF@Ppy. An asymmetric supercapacitors (HSCs) device is made utilizing activated carbon made from banyan wood (BWAC) as the negative electrode and Co9S8/NF@Ppy as the positive electrode to further assess the effectiveness of the Co9S8/NF@Ppy electrode in practical applications. The prepared BWAC material exhibits a high surface area of 1038 m3/g and a tiny pore size of 4 nm. The BWAC electrode exhibits high specific capacitance and volumetric capacitance of 156 Fg−1 and 89 Fcm−2 at a low current density of 2 A g−1. The different electrolyte-based assembled Asymmetric Solid-State Supercapacitor (ASSN and ASSK) constructed of Co9S8/NF@PPy and BWAC also exhibits power densities (4284, 2053Wkg−1) and energy densities (47.6, 73.5 Whkg−1) at a low current density of 2 A g−1. This study provides a framework for the optimal material preparation and logical electrode material design, including the enhancement of the characteristics of Ni foam-based materials for use in supercapacitors.