Graphene [35], a two-dimensional carbon material consisting of a single- layer of sp2 hybridized carbon atoms, has been considered as an outstanding candidate electrode material for supercapacitors due to its unique properties, such as exceptionally high specific surface area (2630 m2/g, higher than that of CNTs and commercial AC, and major surface of graphene is exterior surface readily accessible by electrolyte), excellent electrical conductivity, and stable chemical properties [36–38]. Many works have been reported based on graphene and modified graphene for supercapacitors. Unfortunately, the EDL capacitance value measured is far lower than the theoretical one (550 F/g) provided the entire surface is fully utilized [39], mainly because graphene sheets have the inevitable tendency to restack themselves during all procedures of graphene preparation and subsequent electrode production. Moreover, the low packing density, with a value as low as ~0.005 g/mL, is another drawback of graphene. In the past, many works were interested in materials with high specific surface area, and the specific capacitance per unit weight is mostly adopted to judge the performance of the electrode materials. However, the specific capacitance per unit volume (Wh/L) is of prime importance for practical applications as the space for the power unit is always limited [2]. The volumetric capacitance is mainly affected by the packing density of electrode materials. It is worth noting that many works have focused on designing graphene-based EDLC electrode materials with high SSA, excellent electrical conductivity, and high packing density, and their results indicate that graphene-based materials are hugely favorable for their application to EDLCs.