Designing strategically functionalized conjugated microporous polymers with pyrene and perylenetetracarboxylic dianhydride moieties with single-walled carbon nanotubes to enhance supercapacitive energy storage efficiency

Abstract

We utilize straightforward and traditional Sonogashira coupling reactions to synthesize two conjugated microporous polymers linked with pyrene (referred to as PyT-PTCDA and PyT-PHTD CMPs) by combining the common precursor of 1,3,6,8-tetraethynylpyrene (PyT) with 1,7-dibromo-3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA-Br2) and 3,6-dibromophenanthrene-9,10-dione (PHTD-Br2). Various analytical techniques, including spectroscopy and microscopy, are employed to characterize these two PyT-CMP materials. The PyT-PTCDA CMP exhibits notable thermal stability (with a decomposition temperature of 351 °C and a char yield of 61 wt %). We combine the PyT-PTCDA and PyT-PHTD CMPs with exceptionally conducting single-walled carbon nanotubes (SWCNTs) through π-π stacking interactions between SWCNTs and PyT unit to improve their electrical conductivity and electrochemical performance. Electrochemical evaluations reveal that the PyT-PTCDA CMP/SWCNTs nanocomposite shows an impressive capacitance of 376 F g−1 (at 0.5 A g−1) in a three-electrode system. After undergoing 5000 cycles of charging and discharging, it maintained 98 % of its original capacitance while demonstrating an energy density of 52 Wh/kg. Additionally, in a symmetric coin cell system, the energy density is 17 Wh/kg and the capacitance is 119 F g−1 for PyT-PTCDA CMP/SWCNTs. This approach presents a promising avenue for developing high-performance supercapacitors by strategically blending PyT-CMPs with highly conductive SWCNTs.