Highly-curved carbon nanotubes supported graphene porous layer structure with high gravimetric density as an electrode material for high-performance supercapacitors

Graphene aerogel is one of the most promising candidates for supercapacitors electrode material because of its high specific surface area and good electronic conductivity. However, the extremely low gravimetric density seriously limits its further practical applications. In this paper, a compression strategy was utilized to increase the gravimetric density by forming a unique highly-curved carbon nanotubes supported graphene porous 3D layer structure. The structure and morphology were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectrum and N2 adsorption/desorption measurement. Results demonstrate that the highly-curved carbon nanotubes between the graphene layers can prevent the restacking of the graphene layers. The newly formed structure retains the merits of graphene aerogel such as high specific surface area, good electronic conductivity, and porous structure. The electrochemical performance was investigated by a galvanostatic charge-discharge test (GDC) and a specific capacitance of 246.3 F g−1 was achieved, endowing it with great application potential as an supercapacitors electrode material.