Polyaniline/Polydopamine-Regulated Nitrogen-Doped Graphene Aerogel with Well-developed Mesoporous Structure for Supercapacitor Electrode

Abstract

Graphene-based materials have been widely studied in the field of supercapacitors. However, their electrochemical properties and applications are still restricted by the susceptibility of graphene-based materials to curling and agglomeration during production. In this study, a nitrogen-doped graphene aerogel (NGA) based on the regulation of polydopamine (PDA) and polyaniline (PANI) is proposed for the development of supercapacitors using industrial grade graphene oxide (GO, 2.67 m2/g) as raw material. Due to the rigidity of the PANI, agglomeration is prevented during the reduction of GO sheets. Meanwhile, the flexibility and adhesion of the PDA ensure a stable interaction between the graphene sheets and the PANI. NGAs feature a well-developed mesoporous structure and a high content of nitrogen, which enables the rapid transfer of ions inside them. As revealed by density functional theory (DFT) calculations, NGA heterojunction is characterized by high electronic conductivity, fast electron transfer, and low adsorption energy. For this reason, the supercapacitor obtained with NGA as an electrode produces an excellent capacitive performance, achieving a high area capacitance (123.6 mF·cm−2 at 0.5 mA·cm−2) and a superior long-cycle compression performance (80.7%, 5000 cycles). This study provides an effective solution for the development of supercapacitor electrodes using low-cost GO as raw materials.