Y‐Shaped Acceptor‐π‐Donor‐π‐Acceptor Configured Anthraquinone‐Tethered Phenothiazine Molecular Scaffold for High‐Performance Organic Pseudocapacitors

For the first time acceptor-π-donor-π-acceptor (A-π-D-π-A) based Y-type organic electrode material have been designed and successfully utilized in supercapacitor (SC) application. This Y-type molecular architecture coined as AQ-Im-PTZ-Im-AQ based on anthraquinone (AQ) (A)-imidazole (Im) (π)-phenothiazine (PTZ) (D)-imidazole (Im) (π)-anthraquinone (AQ) (A) in combination with graphite foil (GF). As-fabricated PTZ-Im-AQ/GF and AQ-Im-PTZ-Im-AQ/GF electrode have shown the good energy storage properties in three-electrode supercapacitor system. Moreover, two-electrode symmetric supercapacitor (SSC) device based on AQ-Im-PTZ-Im-AQ/GF electrode exhibited specific capacitance (C_sp) of 68.97 F g^-1 at 1 A g^-1 current density. The specific electron density (ED) of SSC was observed to be 12.06 Wh kg^-1 at a specific power density (PD) of 1798.50 W kg^-1. The SSC device exhibited 81.62 % of C_sp retention after 5000 galvanostatic charge-discharge (GCD) cycles. For real world applications, AQ-Im-PTZ-Im-AQ/GF electrode was tested in symmetric C_sp coin cell with applied potential voltage window of -0.4 to 1.0 V was found to be 112.32 F g^-1 at 0.5 A g^-1. Moreover, it realized high specific capacitance and high energy density of 19.66 Wh kg^-1 at 891.94 W kg^-1 power density. As a results, AQ-Im-PTZ-Im-AQ/GF make as an attractive electrode material for application in next-generation SCs.