From diverse polycyclic aromatic molecules to interconnected graphene nanocapsules for supercapacitors

Abstract

3D interconnected graphene nanocapsules (IGNCs) were prepared by a template strategy coupled with in-situ chemical activation technique via using diverse polycyclic aromatic molecules as building blocks for supercapacitors. Benefiting from the synergistic effects of nano-MgO-template and in-situ KOH activation, the 3D IGNCs feature seemingly incompatible advantages of conductive and porous properties, possessing interconnected thin networks for high electron conduction, short hierarchical pores for fast ion transport, and abundant accessible active sites for ion adsorption. The specific surface area, pore size and pore volume mainly depend on the mass of raw materials and the annealing temperatures. When evaluated as electrodes for supercapacitors, IGNCs exhibit remarkably enhanced electrochemical characteristics such as high capacitance, good rate performance and cycle stability. This work opens up a facile way for high-efficiency preparation of 3D IGNCs from diverse aromatic hydrocarbon sources for energy storage to substitute conventional porous carbons.