A morphology controllable synthesis of 3D graphene nanostructures and their energy storage applications

Abstract

A template-assisted and morphology-controllable synthesis of 3D sulfonated graphene (SG) architectures was reported. The morphology can be controlled between a hollow nanobeads structure and macro-porous structure. The assembly mechanisms are investigated with respect to influencing factors including surface charge of the templating beads and pH value of the precursory solutions. The structures of these SG nanostructures are characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In the application of the Li-ion battery, a maximum specific capacity of 865.5 mA h g⁻¹ for the macro-porous SG electrode is achieved at a current density of 100 mA g⁻¹. Furthermore, even after 100 cycles, more than 99.0% of the specific capacity is still maintained. In the application of supercapacitors, a maximum specific capacity of 256.25 F g⁻¹ for the hollow nanobead SG cell is achieved at a current density of 0.5 A g⁻¹ and a satisfactory capacity retention is also obtained even after 1000 cycles.