Electrochemical capacitor
Disclosed is an electrochemical capacitor comprising a positive electrode exhibiting an irreversible capacity for extending the potential range during a charge/discharge cycle, a negative electrode composed of a material which is capable of reversibly adsorbing/desorbing lithium ions, and an electrolyte solution composed of an organic solvent containing lithium ions.
1. An electrochemical capacitor comprising:
a positive electrode which exhibits an irreversible capacity for extending a potential range in a charging/discharging cycle;
a negative electrode composed of a material capable of reversibly carrying lithium ions;
an electrolyte solution composed of an organic solvent containing lithium ions; and
a scavenger which scavenges a negative electrode activity inhibitor derived from anions contained in the electrolyte solution due to generation of the irreversible capacity in the positive electrode;
wherein the scavenger is contained at a ratio of 2×10 −5 mol to 175×10 −5 mol per 1 mAh of the irreversible capacity.
2. The electrochemical capacitor according to claim 1 , wherein a potential of the positive electrode is not less than 4.23 V vs. Li/Li + .