Abstract: Disclosed herein is a hybrid battery using an electrochemically stable electrolyte composition and electrodes suitable for use in the electrolyte composition. The hybrid battery is non-toxic and highly stable, and has improved high-current charge/discharge characteristics. The hybrid battery comprises an electrode unit consisting of an anode and a cathode, a separator for electrically separating the anode and the cathode, and an electrolyte filled in a space between the anode and the cathode so as to form an electric double layer on surfaces of the anode and cathode when a voltage is applied wherein the electrolyte contains a mixture of a lithium salt, an ammonium salt and a pyrrolidinium salt as solutes in a carbonate-based solvent so that the solute mixture has a concentration of 1.0-2.5 mol/L.

Abstract: Provided is an electric double-layer capacitor. The electric double-layer capacitor includes an electrode portion composed of an anode and a cathode; a separator for providing electrical isolation between the anode and cathode; and an electrolyte solution which is filled in a space between the anode and cathode so as to form electric double-layers on surfaces of the anode and cathode upon application of a predetermined voltage, and in which a solvent and a solute are mixed so as to have a concentration of 1.25 to 2.5 mol/L.