Nitrogen-Doped Holey Graphene Film-Based Ultrafast Electrochemical Capacitors

The comitiercialiied aluminum electrolytic.capacitors (AECs) currently used for alternating current (AC) line filtering are usually the largest components in the electronic circuits because of their low specific capacitances and bulky sizes. Herein, nitrogen-doped holey graphene (NHG) films were prepared by thermal annealing the composite films of polyvinylpyrrolidone (PVP), graphene oxide (GO), and ferric oxide (Fe2O3) nanorods followed by chemical etching with hydrochloride acid. The typical electrochemical capacitor with NHG electrodes exhibited high areal and volumetric specific capacitances of 478 mu F cm(-2) and 1.2 F cm(-3) at 120 Hz, ultrafast frequency response with a phase angle of -81.2 degrees and a resistor-capacitor time constant of 203 mu S at 120 Hz, as well as excellent cycling stability. Thus, it is promising to replace conventional AEC for AC line-filtering in miniaturized electronics.