RECTANGULAR RECHARGEABLE BATTERY HAVING A NOTCH RECESS

摘要

Provided is a rectangular rechargeable battery in which an electrode assembly consisting of an anode, a cathode and a separating film is hermetically sealed inside a rectangular battery casing; wherein the battery casing consists of an oblong main casing body which is open at its upper edge and consists of a metal material, and a casing cap which is joined to the open upper edge of the main casing body and comprises electrode terminals; the thickness of the main casing body is no more than 0.4 mm; a linear notch recess, which ruptures when high pressure occurs inside the battery, is formed on the main casing body showing a stress distribution of no more than 40% of the maximum stress (SMAX) of the casing in the high pressure state; and the notch recess has a structure such that the remaining thickness ("bent thickness") of the main casing body becomes thinner towards the centre from both ends in the length direction.