Different aqueous-based electrolytes have been tested in order to improve the electrochemical performance of hybrid (asymmetric) carbon/MnO 2 electrochemical capacitor (EC). Chloride and bromide aqueous solutions lead to the formation of Cl 2 and Br 2 respectively upon oxidation of the corresponding salt, thus limiting the useful electrochemical window of the MnO 2 electrode and producing gas evolution (in the case of chloride salts) detrimental to the cycling ability of an hybrid device. For sulfate and nitrate salts, MnO 2 electrode exhibits a 20% increase in capacitance when lithium is used as the cation compared to sodium or potassium salts, probably due to partial lithium intercalation in the tunnels of α-MnO 2 structure. The higher ionic conductivity and solubility of LiNO 3 has led to the investigation of this electrolyte in carbon/MnO 2 supercapacitor compared to standard hybrid cell using K 2 SO 4 . A lower resistance increase was evidenced when the temperature was decreased down to −10°C. Long term cycling ability of carbon/MnO 2 supercapacitor was also evidenced with 5M LiNO 3 electrolyte.