Phenazine-integrated conjugated microporous polymers for modulating the mechanics of supercapacitor electrodes

Abstract

Conjugated microporous polymers (CMPs) are attractive materials in numerous interesting fields owing to their microporosity, tunable physicochemical properties, and extended π-conjugated skeletons. However, their limited electrical conductivity restricts their progress as dynamic supercapacitor electrodes. Moreover, dynamic redox building units based on CMPs forming outstanding electrode materials are still unexplored. In the current study, we synthesize and characterize two conjugated microporous polymers (CMPs), abbreviated as TPA-QP and TPA-TBP, which incorporate various redox-active phenazine linkers coupled with triphenylamine (TPA), and then demonstrate them as new supercapacitor electrodes. TPA CMPs display improved surface areas and thermal stabilities of up to 815 m² g⁻¹ and 77.7%, respectively. The physical and electrochemical properties of these CMPs vary depending on the nature of incorporated phenazine units and CMPs, which provide more active sites and show high capacitance as revealed experimentally and computationally. The TPA CMPs exhibit a superb three-electrode capacitance of 356 F g⁻¹ at a current density of 1 A g⁻¹ with an exceptional stability of 97%, which is comparable to those of earlier reported porous materials. A symmetric double-electrode device incorporating the TPA-QP CMP shows an improved specific capacitance of 235.5 F g⁻¹ at 1 A g⁻¹. The current paper provides a fruitful strategy for synthesizing dynamic electrochemical and redox-active CMPs for futuristic supercapacitors.