Patent ID: 8993139
Filing Date: 2015-03-31
Classification: H01M,Y02E,Y02P

Abstract:
1. A sealed secondary battery consisting of: a cylindrical housing which has electrical conductivity and each of whose ends is formed therein with a bottom; an electrode body housed inside the housing and fixed inside the housing; and current collecting plates respectively disposed in both ends of the electrode body in the lengthwise direction inside the housing, wherein a part of at least one of the bottoms of the housing to be a negative electrode is formed as a contact section contacting the current collecting plate and the contact section is electrically connected to the current collecting plate so as to make that bottom of the housing be the negative electrode and to make the other bottom be a positive electrode, wherein the contact section is expanded outwards by a rise in internal pressure of the housing which is sealed so that the electric connection between the contact section and the current collecting plate is cut off, wherein the contact section is formed to be bowed towards the current collecting plate further than the peripheral section of the bottom of the housing, and the concave amount of the contact section from the peripheral section is larger than the board thickness of the part at which the contact section is formed, and wherein after the contact section is expanded outwards by the rise in the internal pressure of the housing, the state at which the electric connection between the contact section expanded outwards and the current collecting plate is cut off is maintained even if the internal pressure of the housing drops.