Unveiling Donor–Acceptor–Donor Organic Electrode Materials for the Fabrication of an Efficient Coin Cell Supercapacitor

In recent years, organic electrode materials (OEM) have been considered as emerging electrode materials for pseudocapacitor (PSC) applications. OEMs improve the performance of pseudocapacitor devices and display an advantage over their counterpart inorganic transition metal oxide electrode materials because of their structural diversity, low cost, manipulation of redox properties, lightweight, flexibility, and eco-friendliness. In addition, OEM displayed higher energy density, improved cycling stability, and tunable charge-storage characteristics. Here, we have investigated the performance of 2,6-di(10H-phenothiazin-10-yl)anthracene-9,10-dione (PTZ-AQ-PTZ) as the donor–acceptor–donor organic redox-active material in combination with conductive reduced graphene oxide (rGO) as PTZ-AQ-PTZ/rGO supercapacitor electrodes in three-electrode supercapacitors (SC), two-electrode symmetric supercapacitors (SSC) and asymmetric supercapacitors (ASC), and symmetric coin cell supercapacitors (SCCS) configuration using aqueous 1 M H₂SO₄ electrolyte solution. The investigated PTZ-AQ-PTZ/rGO electrode in SC, SSC, ASC, and SCCS exhibited excellent electrochemical performance with respective specific capacitance (C_sp), energy density, and power density. In addition, the SCCS device displayed the cycling stability retention of 97.7% over 5000 galvanostatic charge–discharge (GCD) cycles. Further, we demonstrated a prototype cell configuration of PTZ-AQ-PTZ/rGO for powering the red-light emitting diode (LED) at 1.8 V, indicating the as-fabricated electrode materials’ potential application in commercial supercapacitor devices. The present work demonstrated a synthetic feasibility for producing PTZ-AQ-PTZ, thereby offering a way for the development of organic-electrode-based coin cell energy storage devices.