Synthesis and Supercapacitive Performance of Three-Dimensional Graphene Macroform

In recent years, three-dimensional graphene networks have attracted much attention for both fundamental science and researches on their applications in the fields of environment, energy, sensors, adsorbents, electrochemical double-layer capacitors and electrode materials, due to their high specific surface areas, large pore volumes, strong mechanical strengths and rapid mass and electron transport. The assembly of microscale graphene oxide sheets into macroscopic architectures is a challenge for graphene fabrication. In this work, a facile method for the preparation of three-dimensional graphene macroform (3D-RGM) is developed via an in situ self-assembly of reduced graphene nanosheets at 90 ℃ under ambient atmosphere pressure without stirring. The morphology and composition of 3D-RGM are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Raman spectra. The as-synthesized 3D-RGM shows interconnected mesoporous and macroporous structures, and the pore wall is composed of flaky reduced graphene sheets with wrinkles. Furthermore, 3D-RGM presents strong mechanical strength and compressibility. In addition, the work electrode materials for supercapacitor were prepared by direct tableting and the supercapacitive performances of the electrodes were tested using a three-electrode system. The results show that the specific capacitance of 3D-RGM can reach 150 F/g at the current density of 0.1 A/g, and the interface resistance is about 1.3 Ω.