Tetrabenzonaphthalene and Redox-Active Anthraquinone-Linked Conjugated Microporous Polymers as Organic Electrodes for Enhanced Energy Storage Efficiency

Abstract

Various energy storage systems widely utilize conjugated microporous polymers (CMPs) due to their porous architecture and expansive surface area, which facilitate efficient ion transport and storage. In our research, we developed two anthraquinone (ATQ)-based CMPs (ATQ-CMPs) through a Sonogashira coupling method. We used 2,6-dibromoanthraquinone (ATQ-Br2), a redox-active precursor, as a building monomer along with an ethynyl derivative of triphenylamine (TPA-T) and tetrabenzonaphthalene (TBN-T) to afford TPA-ATQ CMP and TBN-ATQ CMP, respectively. We employed techniques, such as thermogravimetric analysis, high-resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR), to characterize the structure and thermal properties of these ATQ-CMPs. The TBN-ATQ CMP displayed extensive Brunauer–Emmett–Teller (BET) surface areas (SBET = 161 m2 g–1) and remarkable thermal stability (temperatures of up to 605 °C). These properties made it an excellent candidate for supercapacitor (SC) electrode materials. The electrodes fabricated using the TBN-ATQ CMP exhibited an exceptionally significant specific capacitance of 393 F g–1 when tested at a current density of 1 A g–1. After 5000 cycles at 10 A g–1, TBN-ATQ CMP still had 74.2% capacitance in a three-electrode setup. We also made a symmetrical device using the TBN-ATQ CMP. This device had a capacitance of 175 F g–1 at 1 A g–1 and was very stable over 2000 cycles, keeping 92.8% of its capacitance. The TBN-ATQ CMP electrode has better electrochemical performance because it has a redox-active ATQ unit and high SBET. Our findings pave the way for simple methods of developing and producing efficient CMP materials using TBN and ATQ for high-performance SCs in both three- and two-electrode configurations.