Synthesis of Sulfonyl-2D Covalent Organic Framework/Graphene Composites for High-Performance Supercapacitors

Abstract

Covalent organic frameworks (COFs) are gaining increasing attention in research for energy storage applications. However, COF is prone to limitations such as low conductivity. Enhancing the conductivity by introducing conjugated structures or conductive fillers (e.g., carbon nanotubes, graphene) is one of the solutions to this problem. This work reports a method for the composite of covalent organic frameworks (SLD-COF) prepared using 4,4'- sulfonyldiphenylamine (SLD) and reduced graphene oxide(rGO). This composite material is referred to as SLD-COF/rGO. A simple hydrothermal synthesis method allows for the binding of SLD-COF to the graphene oxide (GO) surface through non-covalent interactions of π–π stacking. SLD-COF provides abundant active sites and pore structures for the composites, which provide more charge transfer channels and enhance the ion migration rate, while GO stabilizes to take advantage of its high conductivity and mechanical stability and both synergistically promote each other to improve the overall electrochemical performance of the electrode materials. The symmetric supercapacitor prepared by it has an energy density of 9.92 Wh kg⁻¹, a power density of 250.3 W kg⁻¹, and a capacitance retention rate of 86.4% after 5000 cycles, with good stability.