PEDOT-modified laser-scribed graphene films as bginder– and metallic current collector–free electrodes for large-sized supercapacitors

Abstract

The rapid development of wearable electronic devices and energy storage devices has increased the demand for flexible, lightweight, and durable supercapacitors. Nevertheless, the cost-effective synthesis of suitable active materials and the facile fabrication of electrodes for energy storage systems remain a challenge for practical applications. In this study, we developed a scalable method for the fabrication of graphene-based supercapacitors, by using a CO2 infrared laser to transform polyimide (PI) films into porous graphene. Furthermore, when modified with oxidatively polymerized poly (3,4-ethylenedioxythiophene) (PEDOT), the conductivity of the graphene films was enhanced significantly. The resultant films could be fabricated directly for use in supercapacitors without employing metallic current collectors. The current collector–free supercapacitors exhibited excellent electrochemical properties, rivaling those obtained from corresponding devices featuring metallic current electrodes. An assembled device having a large working area (4 × 4 cm2) displayed reversible capacities of 115.2, 97.0, and 78.4 F/g at rates of 0.5, 2, and 6 A/g, respectively. Moreover, only slight losses in capacitance occurred after 4000 charge/discharge cycles and 2000 bending cycles, indicative of remarkable cycling life and mechanical stability.