A conjugated microporous polymer–graphene composite porous sandwich-like film for highly efficient flexible supercapacitors

Abstract

Fabrication of high-performance flexible solid-state supercapacitors (FSSCs) is significant for the booming development of flexible wearable electronic devices. Herein, we develop a novel porous sandwich-like film electrode material composed of rGO and conjugated microporous polymers (CMPs) to achieve FSSCs with high specific gravimetric capacitance and good rate performance by a simple vacuum filtration fabrication process coupled with a reduction process. The designed porous sandwich-like structure is beneficial for exposing more active sites, creating numerous ion transport channels, and enhancing the electron transport between rGO and CMPs. To overcome the poor processability of CMPs, we introduce a third monomer containing hydroxyl functional groups to synthesize a redox-active imine N-containing CMP (PTPAH) with high surface area via the one-step Buchwald–Hartwig (B–H) cross coupling reaction. The obtained porous sandwich-like composite film electrode of PTPAH and rGO (PTPAH@rGO) shows a high specific gravimetric capacitance (545 F g⁻¹ at a current density of 1 A g⁻¹) and good rate performance (450 F g⁻¹ at a current density of 10 A g⁻¹). PTPAH@rGO FSSCs fabricated with PVA/H₂SO₄ as a gel electrolyte demonstrate an excellent capacitance (220 F g⁻¹) and a high power density (3345 W kg⁻¹). This work offers a novel strategy to improve the dispersibility and processing performance of CMPs and provides a pathway to prepare CMP-based composite films as high-performance flexible electrodes, showing promising potential application as a next-generation power source.