All solid-state redox supercapacitors based on supramolecular 1,5-diaminoanthraquinone oligomeric electrode and polymeric electrolytes

Supramolecular conducting oligomeric 1,5-diaminoanthraquinone (DAAQ)-based all solid-state redox supercapacitors have been fabricated with the solid polymer electrolyte, poly vinyl alcohol (PVA)–H3PO4 blend and polymeric gel electrolyte poly methyl methacrylate (PMMA)–ethylene carbonate (EC)–propylene carbonate (PC)–tetra ethyl ammonium perchlorate (TEAClO4) system. The films of gel electrolyte of the optimized composition PMMA (35 wt.%)–EC:PC (1:1 v/v)–1 M TEAClO4 and polymer electrolyte PVA–H3PO4 (50:50 w/w) blend exhibited high ionic conductivity (10−4 to 10−3 S cm−1 at room temperature) with good mechanical strength, suitable for application in electrochemical supercapacitors. The capacitors have been characterized using a.c. impedance spectroscopy, linear sweep voltammetry and prolonged cyclic test. The maximum capacitance value of 3.7–5.4 mF cm−2 (equivalent to single electrode capacitance 125–184 F g−1 of DAAQ electrode) has been observed for the PMMA–gel electrolyte based capacitor. This corresponds to the energy density 92–135 Wh kg−1. System based on the proton-conducting PVA–H3PO4 polymer blend, however has relatively lower capacitance of 1.1–4.0 mF cm−2 (equivalent to single electrode capacitance of 36–136 F g−1).