Chemically synthesized poly(3,4-ethylenedioxythiophene)–reduced graphene oxide nanocomposite for supercapacitor applications

Abstract

Supercapacitors have become popular as essential energy storage devices because of their remarkable energy density, outstanding power density, and exceptional stability cycles. The choice of electrode active material is a crucial factor in determining the superior electrochemical performance of supercapacitors. Poly(3,4-ethylenedioxythiophene) (PEDOT) has the advantage of excellent chemical stability, good cost-effectiveness, and an easy synthesis process to be used as the electrode active material. Nevertheless, it also suffers from drawbacks, such as short electrochemical stability cycles, low surface area, and low theoretical capacitance. To deal with these issues, reduced graphene oxide (RGO) is proposed due to its notable benefits, including its high specific surface area, excellent conductivity, high theoretical capacitance, and extended cycle stability. This thesis work involves the chemical synthesis of a PEDOT-RGO nanocomposite utilizing an in-situ oxidation-reduction approach. The performance of a symmetrical 2-electrode supercapacitor made from a nanocomposite of PEDOT-RGO was evaluated in 1 M H2SO4 electrolyte. The PEDOT-RGO has a maximum specific capacitance of 158 F/g when subjected to a current density of 0.25 A/g. Furthermore, it maintains over 80% of its capacitance after conducting 10000 continuous galvanic charge-discharge (GCD) cycles. Furthermore, the PEDOT-RGO supercapacitor demonstrated enhanced energy and power density, with approximately 1 Wh/kg and 351 W/kg increase, respectively, compared to PEDOT. These findings suggest that the incorporation of RGO into PEDOT improves its supercapacitive performance, offering the potential for developing high-performance supercapacitors.