This work presents a new class of porous graphene particles with a three-dimensional microscale network and an ultrahigh specific surface area (2590 m2 g−1), which is obtained by the KOH activation of a compact graphene hydrogel. As supercapacitor electrodes, such porous graphene particles show high compressibility and little capacitance loss when subjected to a compressive force up to 40 MPa, yielding an excellent volumetric performance with an ionic liquid electrolyte. Such carbon materials show great promise for applications needing high volumetric energy.
