An efficient organic supercapacitor based on four thiophene substituted naphthalene diimide unit

Organic material (OM) offers an opportunity to utilize renewable sources to fabricate electrode materials for supercapacitor (SC) applications. OM electrodes have shown great potential in SC applications due to lower cost, lower device weight, high energy density, high power density and longer cycling stability with excellent faradaic reversible redox reactions. Among the reported materials, naphthalene diimide (NDI) is a promising n-type OM to be utilized for fabrication of electrode for pseudocapacitor (PSC) applications. Herein, four thiophene functionalized core substituted NDI (NDI-Th) is designed as donor (D)-acceptor (A) scaffolds to be used as active electrode materials in combination with graphite foil (GF). The NDI-Th could provide redox active surface resulting into higher capacitance due to the PSC charge storage mechanism due to higher conductivity. In a three-electrode PSC system, NDI-Th/GF in 1 M H2SO4 electrolyte shows specific capacitance (Csp) of 173.33F g-1 at 0.5 A/g current density. Moreover, in two-electrode symmetric supercapacitor configuration, the NDI-Th/GF based electrode provides a Csp of 77.76F/g at 0.5 A/g current density and a stable cycle life with 84.83 % capacitance retention after 10,000 GCD cycles. An impressive energy density was found to be 11.66 Wh kg -1 at 899.92 W kg � 1 power density. The NDI-Th/GF electrode material in this work pave a new way to design and fabricate OM based electrodes for high-performance energy storage devices.