Conjugated microporous polymers incorporating pyridine moieties for efficient faradaic supercapacitor energy storage

Abstract

Conjugated microporous polymers (CMPs) are significant materials owing to their π-conjugated frameworks and microporous architecture. However, several CMPs have limited electrical conductivity and redox efficiency, making them unsuitable as dynamic supercapacitor electrodes. In this work, we prepared a particular family of redox-active CMPs, namely TPP-DBTh and BTPP-DBTh CMPs, with triphenylpyridine (TPP) and redox-active benzo[1,2-b:4,5-b′]dithiophene-4-dione (DBTh) units for effective supercapacitor energy storage devices. Combining TPP and redox-active DBTh units into CMP skeletons promotes faradaic energy storage, charge transfer, and conductivity. The final CMPs demonstrate a superior specific capacity relative to previously published conventional CMPs, achieving an impressive three-electrode capacitance of up to 221.86 F g⁻¹ at a current density of 0.5 A g⁻¹, along with remarkable stability of up to 87.86 % within 10,000 cycles, marking this as one of the highest specific capacities recorded for CMPs. The TPP-DBTh CMP produces a symmetric two-electrode supercapacitor device, which can maintain 91.81 % of their initial capacitance after 2000 cycles. The TPP-DBTh CMP-based device has a high capacitance of 384.61 F g⁻¹, energy density of 77.13 W h kg⁻¹, and power density of 461.53 W kg⁻¹ at 1.2 V. Our findings offer a straightforward method for combining electroactive moieties to create effective supercapacitor devices.