NOVELTY - A safety apparatus comprises casing (212), battery part (211) in the casing, and two tabs (213, 214). The battery part includes first electrode plate, separator, and second electrode plate arranged in order. The second tab is connected to one edge of the four edges of the second electrode plate via a second tab welding part (214a) and protrudes from the casing. A portion of the first tab ruptures when the two tabs are short circuited, thus preventing two plates from being short-circuited.    USE - The safety apparatus is useful for responding to a battery short-circuit condition, particularly for a high power lithium secondary battery producing current of 100 A or more, as may be used in hybrid automobiles.    ADVANTAGE - The safety apparatus allows positive temperature coefficient function in small space at low cost whilst eliminating the requirement for additional installation space and additional connection work for an actual PTC element, and prevents explosions of battery when short-circuited.    DETAILED DESCRIPTION - A safety apparatus comprises casing, battery part in the casing, and two tabs. The battery part includes first electrode plate, separator, and second electrode plate arranged in order. The first tab is connected to one edge of the four edges of the first electrode plate via first tab welding part (213a) and protrudes from the casing. The second tab is connected to one edge of the four edges of the second electrode plate via a second tab welding part and protrudes from the casing. A portion of the first tab ruptures when the two tabs are short circuited, thus preventing two plates from being short-circuited. The first tab has resistance of 2.36 x 10-4 to 1.64 x 10-5 Omega. The first tab has panel shape and is 0.1-0.4 mm thick. The first tab has length of edge parallel to the casing is 20-200 mm and length of edge perpendicular to the casing is 18-50 mm. The first tab has area of 2-80 mm2. The first tab welding part has area of 40-800 mm2.    DESCRIPTION OF DRAWING(S) - The figure shows plan view of the lithium secondary battery including short circuit safety apparatus.    Lithium secondary battery (210)    Battery part (211)    Battery part (212)    Casing (212)    Two tabs (213, 214)    First tab welding part (213a)    Second tab welding part (214a)