Incorporating Conducting PEDOT between Graphene Films for Stable Capacitive Energy Storage

Abstract

Suppressing sheets stacking of graphene oxide (GO) films by introducing conductive polymers proves to be an effective way to develop graphene-based electrodes for electrochemical energy storage. This work reports a facile a method for the preparation of poly(3,4-ethylenedioxythiophene)/GO (PEDOT/GO) hybrid films by incorporating poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) between GO sheets. The subsequent dissolution of partial PSS substantially promotes the ion diffusion kinetics and simultaneously enhances film conductivity up to 931 S m–1. It has a specific capacitance of 210 F g–1 and retains 98% of its capacitance after 10 000 cycles. Further reduction of PEDOT/GO film in hydrazine vapor converts GO to chemically reduced graphene oxides (rGO) and simultaneously expands the compact film into a foam-like structure. Due to more opened electrochemically active sites and favorable ion pathways, the enhanced capacitive performance including larger specific performances of 257 F g–1, higher rate capability of 54% in 0.2–10 A g–1, and superior cycling stability with 97% capacitance preservation over 10 000 cycles has been achieved for the PEDOT/rGO film. An all-solid-state capacitor assembled with PEDOT/rGO films also demonstrates good capacitive performance and satisfactory flexibility at large bending angles.