Electroactive redox-active pyrene and hexaazatriphenylene-based conjugated microporous polymers as positive electrode with MXene film as negative electrode for high-performance asymmetric supercapacitor electrode

We herein present the development of conjugated microporous polymers (CMP), PTB–HATN CMP, meticulously engineered through a highly efficient Sonogashira coupling reaction between tetraethynylpyrene (PTB) and hexabromodiquinoxalino[2,3-a:2′,3′-c]phenazine (HATN-6Br). The resulting conjugated framework features an interconnected microporous–mesoporous architecture, endowing it with a substantial Brunauer–Emmett–Teller (BET) surface area of 198 m2 g−1. The PTB–HATN CMP as positive electrode displayed pronounced pseudocapacitive behavior, arising from the synergistic interplay of its abundant redox-active sites, π-conjugated pyrene units, and electron-deficient HATN cores. Notably, PTB–HATN CMP electrode exhibited a specific capacitance (SC) of 1010.2 F g−1 at 1 A g−1, surpassing the performance of many previously reported conjugated polymers and CMP-based electrodes in 3 M H₂SO₄. Moreover, excellent cyclic stability with almost 99% columbic efficiency was maintained for all cycles, and also retained 97.6% of its capacitance for continuous 5000 charge–discharge cycles, highlighting its robustness and practical potential for energy storage applications. Moreover, when all pseudocapacitive electrodes, namely MXene (Ti₃C₂T_x) film as negative electrode and PTB–HATN CMP as positive electrode, are integrated, the resultant asymmetric supercapacitor device (ASC) of Ti₃C₂T_x//PTB-HATN CMP, which enhances the charge storage capability via all pseudocapacitive redox active sites, achieves a high SC value of 230 F g−1 at 1 A g−1. This work showcases the promising impact of rationally designed CMPs integrated with MXene film, positioning them as next-generation materials that offer a versatile and powerful pathway for advancing electrochemical energy storage technologies.