Abstract
Recently, ionic liquids have drawn interest in the form of organoelectrolytes for supercapacitors as they show a broad electrochemical stability window and thereby increased energy density. In addition to that, electroactive additives are the most promising ones to enhance the efficiency of supercapacitors. However, researchers have focused on improving the electrochemical performance of supercapacitors by incorporating electroactive additives in aqueous electrolytes, where they show a narrow electrochemical stability window. This research focuses on introducing electroactive organic additives such as hydroquinone, into the ionic liquids (ILs). For this study, the least explored unsymmetrical dialkylated triazolium-based IL 1-propyl-4-butyl-triazolium hexafluorophosphate was synthesized. The prepared IL is characterised using (1)H NMR spectroscopic technique. Electrochemical studies were conducted to compare the impact of the additive with the IL. The synthesis of an ionogel polymer with the synthesized IL and the organic additive which is hydroquinone highlights its potential uses as a gel polymer electrolyte used in electrochemical energy storage technologies. In order to evaluate the electrochemical applicability, two Swagelok cells were constructed: a pristine gel polymer electrolyte (PGPE) which contains only the IL and a hydroquinone incorporated gel polymer electrolyte (HQGPE). It was subjected to studies like Cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS) and Galvanostatic charge- discharge studies (GCD). For PGPE system, GCD testing at 0.28 A/g provided 80.95% retention of capacitance after 1500 cycles, with calculated specific capacitance, power and energy density of 3.02 F/g, 292.98 W/kg and 1.68 Wh/kg respectively. Meanwhile, HQGPE system tested at 0.44 A/g provided 78.51% retention after 1500 cycles, with calculated capacitance, energy density, and power density of 3.75 F/g, 2.083 Wh/kg, and 552.61 W/kg, respectively. The comparison between PGPE & HQGPE emphasises on the influence of organoadditive on the electrochemical characteristics of the gel polymer electrolyte. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1038/s41598-025-32609-3.