Electrochemical supercapacitor with thiourea-based aqueous electrolyte

The capacitance of electrochemical capacitors may be improved by providing additional charge originating from faradaic reactions. Faradaic reactions may originate from appropriate modification of the electrode or the electrolyte. The introduction of thiourea to the electrolyte is a novel approach. The tests in 1 mol dm−3 of Na2SO4 aqueous electrolyte (pH = 6.2) with thiourea addition showed a reversible redox process resulting in the increase of capacitance from 131 F g−1 for non-modified electrolyte to 229 F g−1 for those modified with thiourea.