Abstract
We demonstrate an aqueous supercapacitor based on self-standing, porous, hydrophilic, and 26-μm-thick activated carbon nanofoam. The device delivers an areal (volumetric) capacitance of 95.4 mF/cm(2) (18.3 F/cm(3)) at 2 mA with retention of 103% at 20 mA and achieves a voltage of 1 V, superior compared to pristine and annealed examples.