Secondary battery system

A secondary battery system comprising:

• a cell assembly member comprising a plurality of cylindrical secondary battery cell;
• a battery module accommodating at least one or more of the said cell assembly member;
• an upper space and a lower space formed inside the said battery module and formed between the case of the said battery module and the said cell assembly member to allow a fire extinguishing agent to move into the battery module smoothly;
• a fire extinguishing agent spray opening formed on a side of the battery module to allow the fire extinguishing agent to be sprayed into the upper space or the lower space;
• a spray nozzle disposed in the said fire extinguishing agent spray opening;
• wherein the said cylindrical secondary battery cell has cylindrical shape having smaller capacity than pouch type or polyhedral type secondary battery cells, and the said spray nozzle is a permanently open nozzle for early fire extinguishing because fire spreads more rapidly inside the said battery module compared to a battery module with pouch type or polyhedral type secondary battery cells;
• and
• wherein the said spray nozzle is configured such that its distal end portion is inserted in one end of a tube made of a certain length of insulation material, and the other end of the said tube having a circular cross-section is disposed in the said upper space;
• and
• and further comprising an ignition member for the ignition of a heat source member by an electrical signal, and a heat source supply member comprising a heat source member connected to and ignited by the said ignition member;
• and
• wherein the said heat source supply member is molded with a heat-sensitive material, and
• wherein the other end of the said tube is filled with the heat-sensitive material so that the opening of the other end of the said tube is closed by the heat-sensitive material, and
• wherein the heat source member burns through the ignition of the said ignition member when a fire is detected and the heat-sensitive material increases in temperature and melts, whereby the said tube opens.