Conjugated microporous polymers incorporated redox-active hexaazatrinaphtylene and triphenyltrazine moieties for efficient faradaic supercapacitor energy storage

Conjugated microporous polymers (CMPs) have attracted considerable attention owing to their microporous structures and versatile physicochemical behavior, combined with π-conjugated frameworks. However, their practical application in electric storage devices, such as supercapacitors, is hindered by their inherently low electronic conductivity and limited redox-active functionality, which limit specific capacitance and charge–discharge stability. Addressing these challenges, this study introduces two novel redox-active conjugated CMPs based on hexaazatrinaphtylene (HATN), namely TPA-HATN-CMP and TPT-HATN-CMP. These materials were synthesized Suzuki coupling polymerization of 2,8,14-tribromodiquinoxalino[2,3-a:2′,3′-c]phenazine (HATN-Br₃), tris(4-bromophenyl)amine (TPA-Br₃), tris(4-bromophenyl)-1,3,5-triazine (TPT-Br₃), and 1,4-phenylenediboronic acid (pH-2BO). The resulting TPA-HATN-CMP and TPT-HATN-CMP demonstrated remarkable thermal stability, with T_d10 values of 633 and 679 °C, and high surface areas of 459 and 428 m2 g−1, respectively. The incorporation of redox-active HATN units into the CMP backbone significantly enhanced their charge mobility, faradaic charge capabilities, and electron transfer efficiency. In a three-electrode configuration, the TPT-HATN-CMP achieved an impressive specific capacitance of 505 F g−1 along with exceptional capacitance stability of 96.8% after 5000 cycles. The symmetric two-electrode supercapacitor assembled with TPT-HATN-CMP delivers a specific capacitance of 219.4 F g−1 and an energy density of 22.01 Wh kg−1 at 0.85 V. Moreover, the device exhibited excellent cycling stability, maintaining 80% of its initial capacitance after 5000 successive cycles. The results obtained underscore the suitability of HATN-CMPs as effective electrodes for superior energy storage performance.