Preparation of highly expanded graphene with large surface area and its additional conductive effect for EDLC performance

• Published in: Journal of materials science. Materials in electronics 2015-09, Vol.26 (9), p.6945-6953
• Main Authors: Ullah, Kefayat, Kim, Ick-Jun, Yang, Sun-hye, Oh, Won-Chun
• Format: Article
• Language: English
• Subjects: Alternating current; Capacitors; Characterization and Evaluation of Materials; Chemistry and Materials Science; Electrically conductive; Electrochemical analysis; Electrochemical impedance spectroscopy; Electrodes; Graphene; Materials Science; Optical and Electronic Materials; Supercapacitors
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-015-3313-8

Expanded graphene (EG) has been produced using fast oxidation/intercalation process. The as prepared EG were then used as conductive additive to study the electrochemical properties of activated carbon based electric double layered supercapacitors (EDLCs). The physiochemical properties of EG were studied using scanning electron microscopy, Raman spectroscopic techniques, atomic force microscopy and energy dispersive X-ray analysis. The electrochemical properties were studied using charge/discharge cyclic voltammetry and electrochemical impedance spectroscopy. All the electrochemical tests were carried out in 1 M, TEA BF 4 in acetonitrile as a suitable electrolyte for our AC based supercapacitors. Electrochemical test reveals that EG greatly affect the conductivity of the ions through the AC/EG interface. The specific capacitance remains the same for smaller values of EG in the composites electrodes. These results also evident the optimum loading of graphene in the future graphene based EDLCs.