Porous crumpled graphene with hierarchical pore structure and high surface utilization efficiency for supercapacitor

As a promising active material for supercapacitor, graphene suffers serious restack, which reduces the surface area utilization of electrodes. Porous crumpled graphene (PCG) with hierarchical pore structure is designed in this paper. The spherical morphology of porous crumpled graphene effectively prevents it from restack, and thus dramatically promotes the utilization of pores on the graphene sheets. As electrode in supercapacitor, the specific capacitance per surface area is as high as 20.7 mu F cm(-2) due to the high surface utilization efficiency, which is much higher than that of the traditional activated carbon (6.0 mu F cm(-2)) and porous graphene (6.5 mu F cm(-2)), approaching the theoretical value of 20.9 mu F cm(-2).