Characterization of expanded graphene nanosheet as additional material and improved performances for electric double layer capacitors

This study improved the electrochemical performance of electrochemical double-layer capacitor (EDLC) with an activated carbon (MSP20)-based electrode by adding a small amount of expanded graphene (EG) and styrene-butadiene rubber (SBR). The prepared EG was characterized via X-ray diffraction (XRD) spectroscopy, scanning electron microscopy (SEM), and Raman spectroscopy. Finally, the electrochemical performance of graphene was examined in an electrolyte solution of tetraethylammonium tetrafluoroborate ((C2H5)4NBF4, TEABF4) in propylene carbonate (C4H6O3, PC). The capacitive performance of EDLC was evaluated with the same charge on the positive and negative electrodes by conducting cyclic voltammetry, charge and discharge measurements, electrochemical impedance spectroscopy and electron spin resonance analysis.