Enhancing electrochromic supercapacitor electrode performance through different donor compartments in D-A-D type conjugated polymers

Abstract

Conjugated polymers (CPs), particularly donor-acceptor-donor (D-AD) type polymers, have emerged as promising materials as supercapacitor electrode. In this study, 3-hexylthiophene and ethylenedioxythiophene (EDOT) as donor compartments in D-A-D type CPs, with an indenoquinoxalinone-based acceptor, were investigated for supercapacitor electrode performance. Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and UV–Vis spectroscopy were employed to analyze the chemical structures and optical properties of the monomers, respectively. For surface characterization of the polymers, scanning electron microscope (SEM) and Brunauer-Emmett-Teller (BET) analysis were used. Electrochromic behaviors were investigated via spectroelectrochemistry and kinetic studies. The electrochemical performance of the polymers was evaluated through cyclic voltammetry, galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) measurements. The specific capacitance, energy density, and power density of the polymers were compared. Results showed that they were promising electrochromic material for supercapacitor application due to their high specific capacitance. Since EDOT containing polymer exhibited enhanced electrochemical properties, it was used to construct supercapacitor. Besides cyclic voltammetry and GCD characterization of device, the electrochemical cycling performance of it was assessed to evaluate the long-term reliability of the polymer as supercapacitor electrode material. This study provides valuable insights into the role of donor compartments, specifically 3-hexylthiophene and EDOT in D-A-D type CPs. The findings also highlight the potential of the indenoquinoxalinone-based acceptors in electrochromic supercapacitors. The results contribute to the design and development of enhanced supercapacitor materials with improved energy storage capabilities, offering new possibilities for utilizing D-A-D type polymers with indenoquinoxalinone-based acceptors.