Boosted 2D graphene nanosheets by organic-inorganic hybrid cross-linker for an efficient and stable supercapacitor

摘要

Using covalent graphene derivatives in energy storage applications is promising. From this view, covalently cross-linked graphene oxide (GO) nanosheets are designed using polyoligomeric silsesquioxanes-propyl-NH2 (POPN). Then, by incorporating cobalt sulfide nanoparticles into the porous scaffold, a high-value nanocomposite is formed. In a typical three-electrode cell, this nanocomposite declared substantial specific capacity of 454 and 438 Fg-1 using cyclic voltammetry (CV) and charge-discharge (GCD) assessments. The device is assembled via two identical electrodes containing RGO-SiO3-NH2-poss-NH2-SiO3RGO/cobalt sulfide (RGO-Si-POPN-Si-RGO/CoS2). Utilizing CV and GCD methods, specific capacitances of 328 and 315 Fg-1 are realized at a sweep rate and current density of 2 mVs-1 and 0.5 Ag-1, respectively. The device presents desirable energy density of 18.5 Whkg-1 at the power density of 325 Wkg-1. More impressively, around 97.9 of the specific capacitance is retained after 5000 charge-discharge cycles. The results confirm exceptional capacitive capabilities and super stability of the nanocomposite suitable for practical systems.