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

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 CO(2 )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 x 4 cm(2)) 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.