A hybrid supercapacitor has two electrodes, one of which functions as a cathode, and the other as an anode. The hybrid supercapacitor further includes an electrolyte arranged between the cathode and the anode. The electrolyte contains a solvent selected from the group consisting of methanol, 1-propanol, 1-heptanol, ethyl acetoacetate, ethylene glycol, diethylene glycol, glycerol, benzyl alcohol, di-n-butyl phthalate and mixtures thereof.