Preparation of a graphene-based composite aerogel and the effects of carbon nanotubes on preserving the porous structure of the aerogel and improving its capacitor performance

A graphene-based aerogel is a promising candidate to be used as a novel supercapacitor due to its unique three dimensional interconnected porous structure and high specific surface area. However, the rolling press process is generally applied in the fabrication of a supercapacitor, in order to reduce contact resistance and upgrade specific volume capacitance. This process tends to deform or destroy the porous structure, and significantly prevents the obtained supercapacitor from achieving its expected performance. In order to improve the pressure resistance of graphene-based aerogels during the rolling press process, a carbon nanotube supported graphene-based composite aerogel (GCA/CNT) with a high specific surface area of 811.5 m2 g−1 was fabricated using a facile two-step process. It was found that the incorporation of carbon nanotubes into the graphene-based aerogel can effectively enhance its pressure resistance and significantly reduce the deformation of the porous structure, especially in the mesoporous region. Furthermore, the resulting GCA/CNT composite aerogel exhibited a remarkably improved electrical conductivity and subsequent superior rate performance due to the formation of a graphene/carbon nanotube three dimensional conductive network.