Electrical properties of hydrocarbon-derived electrolytes for supercapacitors

The paper evaluates the essential electrical properties-capacitance and equivalent series resistance (ESR)-of hydrocarbon-derived electrolytes for supercapacitors using galvanostatic, constant resistance charge-discharge, cyclic voltammetry, and AC impedance measurements. The electrolytes were systematically prepared from six hydrocarbon-derived compounds, which have different carbon chains and functional groups, with the treatment of concentrated sulfuric acid (H₂SO₄). Both electrical properties seem to be in conformity throughout these measurements, with the longer main carbon chain compounds giving higher capacitance and lower ESR values. Comparison between these electrolytes and the typically used aqueous solutions in supercapacitor research-1M H₂SO₄, 5M potassium hydroxide, and 5M sodium hydroxide-showed that the produced electrolytes give the highest capacitance value up to 30 times more than that of typical aqueous solutions. It is believed that with further treatment these hydrocarbon-derived electrolytes can potentially be used in supercapacitors as better performing electrolytes than aqueous solutions and at a relatively low cost compared to organic solutions.