Graphite nanosheets as an electrode material for electrochemical double layer capacitors

In this paper, the effect of ion sizes of cations and anions on the charge storage capability of graphite nanosheets is investigated. Electrochemical properties of prepared electrodes are studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques, in 3 M NaCl, NaOH and KOH electrolytes. A scanning electron microscope (SEM) is used to characterize the microstructure and nature of prepared electrodes. SEM images and XRD patterns confirm the layered structure (12 nm thickness) of the used graphite with an interlayer distance of 3.36 Å. The electrochemical results and the ratio of qO⁎/qT⁎ confirm a better charge storage and charge delivering capability of prepared electrodes in 3 M NaCl electrolyte. The charge/discharge cycling test shows a good reversibility and confirms that the solution resistance will increase after 500 cycles.