Graphene, a single layer of carbon atoms arranged in an hexagonal lattice, has attracted a lot of well-deserved attention due to its high surface area and excellent electrochemical properties. However, graphene is easy to aggregate and has poor volumetric performance when used as electrode material. Here, dense graphene-like porous carbon (GPC) with hierarchical pore structure was fabricated from sheet cellulose made by milling of bleached kraft pulp. The unique pore structure gave rise to specific surface area value of up to 2045 m²/g, providing aboundant storage sites and channels for electrolyte species. The gravimetric (353 F/g) and volumetric (309.7 F/cm³) specific capacitance at 1 A/g were obtained in 6 M KOH aqueous electrolyte. The gravimetric and volumetric specific energy density of the symmetrical supercapacitor were 120.1 Wh/kg and 80.4 Wh/L, respectively, in an ionic liquid electrolyte in acetonitrile. These excellent performances make this material potentially useful for diverse energy storage devices.

石墨烯是排列成六边形晶格的单层碳原子，由于其高表面积和出色的电化学性能，吸引了许多当之无愧的注意。然而，当用作电极材料时，石墨烯易于聚集并且体积性能差。在此，通过对漂白的牛皮纸浆进行研磨而制成的片状纤维素制成具有分级孔结构的致密石墨烯状多孔碳（GPC）。独特的孔结构产生高达2045 m ² / g的比表面积，为电解质提供了丰富的储存位点和通道。重量（353 F / g）和体积（309.7 F / cm ³）在6 M KOH水性电解质中获得1 A / g的比电容。在乙腈中的离子液体电解质中，对称超级电容器的重量比能量密度和体积比能量密度分别为120.1 Wh / kg和80.4 Wh / L。这些出色的性能使该材料潜在地可用于多种能量存储设备。