Construction of Anthraquinone-Containing Covalent Organic Frameworks/Graphene Hybrid Films for a Flexible High-Performance Microsupercapacitor

The porous structural backbone and redox-active of covalent organic frameworks can facilitate the evolution of energy storage equipment with high electrochemical performances. However, the application of covalent organic frameworks as supercapacitor electrode materials in advanced energy storage equipment has been hindered on account of the insufficient conductivity and consecutive impoverished electrochemical performances. Here we give an account of an efficacious method for improving the electrical conductivity of anthraquinone-containing covalent organic frameworks (COFs) by incorporating reduced graphene oxide (rGO) sheets into the COF. Benefiting from the in situ synthesis of the COF along the surface of the two- dimensional rGO nanosheets, the obtained COF@rGO hybrid films possess important intermolecular pi-pi interaction between rGO nanosheets and the COF. Meanwhile, the presence of the COF can avoid accumulation of rGO nanosheets, thereby achieving effective electrolyte ion transportation. Therefore, the optimal COF@rGO film possesses a good specific capacitance of 451.96 F showing breakthrough within COF-based electrodes. In addition, the assembled planar COF@rGO microsupercapacitor (COF@rGO-MSC) delivers a large stable electrochemical window (2.5 V), a good energy density (44.22 W h kg(-1)), and an excellent structural stability.

Automated summary

This paper presents an efficient method for improving the electrical conductivity and electrochemical performances of covalent organic frameworks (COFs) by incorporating reduced graphene oxide (rGO) sheets. The COF@rGO hybrid films obtained exhibit important intermolecular interactions and effective electrolyte ion transportation, resulting in a high specific capacitance. The assembled COF@rGO microsupercapacitor shows a large electrochemical window, good energy density, and excellent structural stability.