New Carbazole-Based Polymer with a D–A System as a Highly Stable Organic Electrode Material for an Asymmetric Supercapacitor

Over the past few decades, conductive polymers have captured significant focus due to their distinct conducting properties and enhanced application in energy storage devices. In this regard, a novel strategy of donor–acceptor type polymer have been synthesized via the direct arylation polymerization method using palladium acetate as a catalyst. The conducting polymer (named SP) exhibited a good thermal stability of 286.5 °C and possessed a lower band gap of 2.3 eV which was determined from the optical and electrochemical techniques. The SP polymer exhibits a three-electrode specific capacitance of 611.2 F g–1 in 1 M KOH at a current density of 1 A g–1. Further, the synthesized polymer was applied as a positive electrode material, and activated carbon was used as a negative electrode material in the asymmetric system. At 2 A g–1 current density, the specific capacitance of the supercapacitor device was determined to be 140.13 F g–1. It was observed that an excellent energy density of 52.69 W h kg–1 at 2334 W kg–1 power density exhibited good cyclic stability up to 10,500 cycles with a retained initial capacity of 92.6%.