A Straightforward Modification of Electrochemically Exfoliated Graphene to Improve the Electrical Properties of Supercapacitor Electrode
Oktaviardi Bityasmawan Abdillah(a), Octia Floweri(b), Akfiny Hasdi Aimon(a), Ferry Iskandar(a,c*)

a) Department of Physics, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung, Indonesia
b) Research Center for Advanced Materials, National Research and Innovation Agency (BRIN), Komplek Puspiptek, Serpong, South Tangerang 15314, Banten, Indonesia
c) National Center for Sustainable Transportation Technology (NCSTT), Institut Teknologi Bandung, Jalan Ganesha 10, Bandung, Indonesia
*ferry[at]fi.itb.ac.id

Abstract

The enhancement of electrode performance is an essential aspect of realizing energy storage devices capable for application in electrical vehicles. Among many materials, graphene is one of the exciting candidates to improve the performance of electrodes in energy storage devices due to several remarkable properties, i.e., high electrical conductivity, large surface area, and high electrochemical stability. Electrochemical exfoliation is an interesting method to fabricate graphene from graphite raw material with simple preparation, eco-friendly, and allows easy tunability of the resulted product. However, the resulting graphene is often suffered to restack during the drying process, reducing its performance. In this work, a modification of electrochemical exfoliation by means of ultrasonication post-treatment was introduced to minimize the restacking of graphene sheets. The ultrasonicated graphene produces a higher exfoliation degree, thus improving its surface area as indicated by Scanning Electron Microscopy (SEM), Raman spectroscopy, and Brunauer-Emmett-Teller (BET) characterization. The prepared samples were tested as an electrode of a supercapacitor, which obtained the specific capacitance of 140.9 F/g for the ultrasonicated samples, which is higher than without ultrasonication treatment (79.0 F/g) at a current density of 0.5 A/g. Moreover, the ultrasonicated graphene also exhibits an improvement of capacitance of 140% after 10000 times charging-discharging cycles compared to the first cycle. The results indicate that ultrasonication can be applied as a facile post-treatment to enhance the performance of an electrochemically exfoliated graphene-based electrode.

Keywords: electrode, graphene, electrochemical exfoliation, ultrasonication, supercapacitor

Topic: Battery Technology and Management System