Electric energy storage device and method of charging and discharging the same

摘要

Disclosed are an electric energy storage device having a good cycle characteristic and a temperature characteristic and a method of charging and discharging the electric energy storage device. The electric energy storage device including a capacitor and a secondary battery combined in series is provided. When the capacitor of the electric energy storage device is an electric double layer capacitor, the capacitor is used to the voltage of OV or less to increase an available energy usage.