Efficient symmetric supercapacitors employing molecular engineered pyrazine functionalized perylene diimide electrode materials

Abstract

Redox active small organic molecules (OM) are the promising materials for energy storage applications. The practical utilization of such materials in combination with excellent redox-active material is advantageous to enhance the specific capacitance (Csp). Herein, naphthalene diimide (NDI) and perylenediimide (PDI) molecules linked with pyrazine (Pyr) are exploited as faradiac reversible redox-active material on graphite foil (GF) surface to act as electrode materials in supercapacitor (SC) device. The as-fabricated NDI-Pyr/GF and PDI-Pyr/GF electrodes were optimized in three-electrode SC device in view of their electrochemical performance. The NDI-Pyr/GF and PDI-Pyr/GF in SC device demonstrated a Csp of about 260 and 302 F g−1, respectively at 0.5 A g−1 current density. However, in two-electrode symmetric supercapacitor (SSC) device i.e. PDI-Pyr/GF//PDI-Pyr/GF exhibited excellent Csp of about 192 F g−1 at 1 A g−1 current density with longer cycling stability with 88.13% after 4000 galvanostatic (GCD) charge/discharge cycles. Furthermore, an excellent energy density of 54 Wh kg−1 at a power density of 2700 W kg−1 is provided by the SSC device. These results suggest that the as-prepared PDI-Pyr/GF//PDI-Pyr/GF have practical energy storage application in OSC devices.