Polyacrylamide-derived carbon materials: outstanding enhancement of supercapacitor capacitance simply by introducing redox additive of p-aminobenzenesulfonate into KOH electrolyte

Abstract

How to effectively improve capacitances is still challenging in the field of supercapacitors. In this work, a simple but efficient redox additive of sodium p-aminobenzenesulfonate has been incorporated into KOH electrolyte, which can largely elevate the capacitances of carbon-based supercapacitors (produced by the template carbonization of polyacrylamide and zinc metal). It clearly indicates that the p-aminobenzenesulfonate concentration in KOH electrolyte has exerted a crucial role in the determination of final capacitances as well as energy efficiency. Owing to efficient electron/proton transfer of the p-aminobenzenesulfonate, the C-900-10 sample with the concentration of 10 mmol L⁻¹ can deliver a much higher capacitance of 681.5 F g⁻¹, when measured at 2 A g⁻¹, which is ca. 2.86 times increase than that of pristine one (238.2 F g⁻¹). The present p-aminobenzenesulfonate is anticipated to be employed in KOH electrolyte as efficient redox additive for simply producing high performance supercapacitors.