Highly conductive and flexible thin film electrodes based on silver nanowires wrapped carbon fiber networks for supercapacitor applications

Highlights: •Flexible and conductive electrode was developed for supercapacitor applications. •Silver nanowires wrapping around carbon fiber can improve the conductivity. •Reduced graphene oxide can increase surface area and enhance specific capacitance. •The flexible thin film electrode exhibits a low sheet resistance of 0.99 Ω/□. -- Abstract: Flexible electrodes with high conductivity and mechanical properties play an important role in many essential electronic devices. Herein, we report the fabrication of flexible and conductive PDMS/AgNWs/CFs thin film by using a simple inverted layer-by-layer deposition method. In this structure, conductive carbon fiber (CF) networks embedding in the elastic polymers will help improve the ability to resist deformation of pure polydimethylsiloxane (PDMS) film. Elongated silver nanowires (AgNWs) wrapping on bare CFs can greatly increase the active surface area, improve the electron transfer of CFs, and reduce the contact resistance between the adjacent CFs. As a result, a flexible PDMS/AgNWs/CFs thin film with a low sheet resistance of 0.99 Ω/□ was obtained. The fabricated PDMS/AgNWs/CFs thin film showed great mechanical flexibility with less than 3% decrease in resistance after 275 continuous bending and releasing processes. Moreover, an induced reduced graphene oxide (rGO) layer on the AgNWs wrapped CF networks increases the active surface area. Physical and electrochemical characterization of the fabricated PDMS/AgNWs/CFs and PDMS/AgNWs/rGO/CFs thin film electrodes have been measured. The tightly attached AgNWs and well-coated rGO materials improved high surface area and provided benefit for fast accessibility of electrolyte ions into the microporous structures, indicating the considerable potential for use in flexible supercapacitor applications.