3D porous PEDOT/MXene scaffold toward high-performance supercapacitors

Abstract

3D architectures of conductive polymer, especially PEDOT hold great promise in energy storage and conversion fields. However, the facile construction of 3D PEDOT and its functionalization have still been challenges due to its poor processability. Herein, the fabrication of 3D porous PEDOT:PSS and its functionalization with MXene are realized synchronously through a simple and low-cost self-assembly process. The prominent capacitive performance of MXene, excellent chemical stability of PEDOT:PSS and 3D porous architecture with inhibited aggregation of MXene nanosheets, large amount of active sites, and electrolyte storage chamber endow the PEDOT/MXene-based porous structure with superior capacitive performance than individual PEDOT:PSS or MXene porous and flat structures. Furthermore, the PEDOT/MXene-based porous structure can be applied as a flexible scaffold for the deposition of conductive polymer to construct excellent electrodes for supercapacitors (SCs). When polypyrrole (PPy) is deposited, the prepared porous PEDOT:PSS/MXene/PPy electrode exhibits a high gravimetric specific capacitance of 345 F g−1 at a current density of 0.5 A g−1 and a remarkable capacitance retention of 89 % over 5000 cycles. Based on it, an asymmetric supercapacitor (ASC) with a high energy density of 56.34 Wh kg−1 at the power density of 120 W kg−1, and a capacitance retention of 75 % after 5000 cycles is developed. Besides, the porous PEDOT:PSS/MXene/PPy can be constructed on various substrates in any pattern with high design freedom, thus enabling customizable electrochemical performance. When constructing on a flexible substrate, excellent deformation-tolerant performance is shown. This work provides a high-performance electrode for SCs, as well as a universal route for the construction and functionalization of 3D PEDOT-based structures.