High performance of chemically-modified graphene-based supercapacitor using an effective redox active binder

Abstract

A robust combination of two redox-active materials consisting of self-doped polyaniline (SPAN)–based covalently bonded 4-aminobenzoic acid-bonded graphene (ABG) and a polyamide binder is proposed to promote supercapacitor performance. This strategy for improving the electrode capacity involves bonding SPAN onto a ABG with a high specific surface area. A SPAN-ABG material is formed and polycondensation is applied to 1,5-diaminoanthraquinone (DAQ) and 4,4′-oxydibenzoic acid (DBA), producing a DAQ-DBA polyamide binder with a Faraday effect on charge storage. SPAN-ABG and DAQ-DBA are combined to fabricate supercapacitor electrodes. At a charging-discharging current density of 1 A/g, the supercapacitor capacitance value (550 F/g) of SPAN-ABG (DAQ-DBA) electrode is higher than that (350 F/g) of SPAN-ABG (PVDF) electrode. After testing for 5000 cycles at a current density of 1 A/g, this supercapacitor has charging–discharging capacitance retention of 98.2 %, which is higher than that of supercapacitors with a PVDF binder (97.8 %). The results confirm that these electrode materials fabricated using both redox-active materials of SPAN-ABG and polyamide binder can synergistically enhance supercapacitor performance.