Densely packed porous graphene film for high volumetric performance supercapacitor

Improving volumetric capacitance of supercapacitor is important and challenging for practical application. Here, porous graphene oxide (PGO) is prepared through an efficient method at room temperature after etched by Zn(CH3COO)2 in several minutes. The obtained densely packed porous graphene film (PGF) was constructed by a template-assisted method. And the perforated PGF electrode material exhibits a high volumetric capacitance (CV) of 318.8 F cm−3 in 6.0 M KOH electrolyte at the current density of 1 A g−1. In addition, it exhibited excellent cycling stability, that is 88% retention of capacitance after 10000 charge/discharge cycles in the current density of 5 A g−1. Furthermore, it demonstrates a capacitance of 219.0 F cm−3 (1 A g−1) and a cycling stability of 113% (10000 charge/discharge cycles at 5 A g−1) after assembled into symmetric supercapacitor. So the PGF is promising to be applied in the high performance energy storage devices with lighter quality and smaller volume.