Redox-active triazatruxene-based conjugated microporous polymers for high-performance supercapacitors

Abstract

Conjugated polymers (CPs) have been intensively explored for various optoelectronic applications in the last few decades. Nevertheless, CP based electrochemical energy storage devices such as supercapacitors remain largely unexplored. This is mainly owing to the low specific capacitance, poor structural/electrochemical stability, and low energy density of most existing CPs. In this contribution, a novel set of redox-active conjugated microporous polymers, TAT-CMP-1 and TAT-CMP-2, based on nitrogen-rich and highly conductive triazatruxene building blocks, were successfully designed and synthesized to explore their potential application as efficient and stable electrode materials for supercapacitors. Despite a moderate surface area of 88 m² g⁻¹ for TAT-CMP-1 and 106 m² g⁻¹ for TAT-CMP-2, exceptional specific capacitances of 141 F g⁻¹ and 183 F g⁻¹ were achieved at a current density of 1 A g⁻¹. The resulting polymers exhibited unusually high areal specific capacitance (>160 μF cm⁻²), which is attributed to the pseudocapacitance resulting from redox-active structures with high nitrogen content. More importantly, the TAT-CMP-2 electrode exhibits excellent cycling stability: only 5% capacitance fading is observed after 10 000 cycles at a high current density of 10 A g⁻¹, enabling the possible use of these materials as electrodes in electrochemical devices.