Redox-Active Benzodithiophene-4,8-dione-Based conjugated microporous polymers for High-Performance faradaic supercapacitor energy storage

Abstract

Conjugated microporous polymers (CMPs) are attractive materials due to their microporous architecture, modifiable physical–chemical characteristics, and extended π-conjugated structures. However, their low electronic conductivity limits the development of CMPs with high specific capacitance and excellent charge–discharge stability for supercapacitor energy storage. Furthermore, the redox-active moieties in CMPs for innovative electrode materials are still restricted. Herein, for the first time, two novel redox-active benzo[1,2-b:4,5-b']dithiophene-4,8-dione-based conjugated microporous polymers (DBTh-CMPs), namely, DBTh-TPA and DBTh-TPT CMPs, were prepared through the one-pot Suzuki coupling polymerization of 2,6-dibromobenzo[1,2-b:4,5-b']dithiophene-4,8-dione with triboronic-pinacolates. The DBTh-CMPs exhibited outstanding thermal stabilities (Td10: approximately 608.4 °C; char yield: approximately 71.76%) and surface areas (around 551 m2/g). Interestingly, incorporating redox-active DBTh structures into the backbone of the CMPs resulted in promising conductivity, exceptional faradaic energy storage, and efficient charge transfer. The DBTh-CMPs displayed an exceptional three-electrode capacitance of 1823F g−1 at a current density of 0.5 A g−1 with superior stability of 81.75% over 10,000 cycles; such a value is the largest specific capacity documented via the CMP to date. The two-electrode symmetric supercapacitor device by DBTh-TPT CMP showed a specific capacitance of 609F g−1 and a maximum energy density of 84.5 W h kg−1 operating at a power density equal to 500 W kg−1 and a potential of 1.0 V. The present research supplies a viable strategy for developing electrochemical gadgets and future-oriented supercapacitors.