Nitrogen and sulfur dual-enriched porous organic polymer for superior-performing supercapacitors

Abstract

Porous organic polymers (POPs) offer intriguing options for applications in energy devices, including supercapacitors. Here, we present the synthesis of POP_APTZ-TPDA, a dual-enriched polymer featuring redox-active triazine-nitrogen and thiophene-sulfur. It is achieved through Schiff-base coupling between 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (APTZ) and 2,5-thiphenedialdehyde (TPDA) under ambient conditions. POP_APTZ-TPDA, featuring nitrogen and sulfur units, facilitates rapid charge transport and exhibits reversible electrochemical processes, leading to outstanding faradaic energy storage. The performance of POP_APTZ-TPDA is evaluated within a three-electrode system. It reveals a specific capacitance of 251.4 F g⁻¹ at a current density of 1 A g⁻¹. After undergoing 9900 cycles, it demonstrates a capacitance retention rate of 88.5 %. This performance surpasses that of POP_APTZ-PA, which contains only triazine-nitrogen. Furthermore, by employing POP_APTZ-TPDA as the positive-electrode material, an asymmetric supercapacitor system is assembled. It exhibits an energy density of 86.7 W h kg⁻¹ at 0.2 A g⁻¹ and a power density of 1639.3 W kg⁻¹ at 2 A g⁻¹, outperforming the performance of a device based on POP_APTZ-PA. Our research offers valuable perspectives on the formulation and creation of redox-active POPs enriched with both nitrogen and sulfur, contributing to the advancement of superior supercapacitors.