Phosphine-Based Porous Organic Polymer/rGO Aerogel Composites for High-Performance Asymmetric Supercapacitor

Two-dimensional porous organic polymers (POPs) can offer overlapped π electron clouds between the stacked layers, conjugated skeletons, and multiple high-rate charge carriers transport pathways that include open channels with variable environments. However, in bulk POPs, the active sites tend to be deep-buried and only a small fraction of them could be electrochemically accessible, limiting their corresponding performance. Herein, solvothermal synthesis of phosphine-based POP (Phos-POP, denoted as PP) and rGO aerogel composites (denoted as PPrGOs) is reported where uniform nanosheets of PP can be rapidly grown on rGO aerogel. An asymmetric supercapacitor (ASC) device based on PPrGO-2 cathode and activated carbon (AC) anode can be operated in a wide potential window up to 1.6 V and achieves high cycling stability (88% retained after 12000 cycles) even at a high current density of 7 A g–1. Encouragingly, our ASC device delivers a high energy density of 33.3 Wh kg–1 with a power density of 3996 W kg–1, remaining an exceptionally high power density of 8370 W kg–1 with the downfall of the energy density of 9.3 Wh kg–1, disclosing outstanding capacitive performance. Furthermore, the two-electrode ASC device could light up a red LED for ∼30 s after charging, implying its promising prospect for future energy storage devices. This work provides a way to further enhance the electrochemical performance of POPs based electrode for high-performance SCs.