Abstract: The present invention provides an energy storage system comprising: a battery module formed by connecting a plurality of hollow secondary batteries that have hollow tubes therein, respectively; a safety module that includes a cooling/heating unit that stores a cooling/heating medium therein and an extinguishing unit that stores an extinguishing medium therein; a first circulation channel that interconnects the battery module and the safety module to circulate the cooling/heating medium or the extinguishing medium between the battery module and the safety module; and a battery management system that measures the temperature and pressure of the battery module and opens the cooling/heating unit or the extinguishing unit to supply the cooling/heating medium or the extinguishing medium to the first circulation channel when the temperature and pressure of the battery module reaches a preset value.

Abstract: A hollow core secondary battery, including: an outer container having a hollow with open opposite ends and containing an electrode assembly therein; an inner container having a hollow with open opposite ends and being inserted in a central portion of the electrode assembly; and a vent unit provided on or in the inner container, wherein, when an internal pressure of the battery is increased above a predetermined value, the vent unit is ruptured to allow for gas and heat to be exhausted to an outside through the hollow of the inner container.

Abstract: A hollow core secondary battery, including: an electrode assembly comprising a pair of electrode plates and a separator disposed between the pair of electrode plates; an outer container in which the electrode assembly is received; an inner container inserted into a central portion of the electrode assembly, the inner container being hollow; a first terminal assembly assembled at a top portion of the outer container, the first terminal assembly into which a top end portion of the inner container is inserted; and a second terminal assembly assembled at a bottom portion of the outer container, the second terminal assembly having a central portion into which a bottom end portion of the inner container is inserted.