SECONDARY BATTERY

摘要

When a temperature inside a secondary battery becomes high and a gas pressure inside a battery case increases, an inversion plate is pressed due to the gas pressure so as to project and curve in a projecting manner toward an external terminal board. Due to such a deformation, a load is transmitted to a current interruption piece via a load transmission portion. At this time, due to a pushing-up force of the load transmission portion, a vulnerable breaking portion forming part of a peripheral edge of the current interruption piece breaks, so that the current interruption piece is displaced to bend in a V-shape via a folding portion. As a result, the secondary battery is brought into an unusable state. Such a configuration can attain simplification of a structure to interrupt a current.

主权项

1. A secondary battery comprising:
an external terminal board placed on a cover portion of a battery case via an insulator, the external terminal board having an electrical path that is conductive from a collector terminal inside the battery case to a terminal; a first displacement portion provided in the cover portion and displaceable so as to project toward the external terminal board at a predetermined pressure inside the battery case; a second displacement portion provided in the external terminal board and projectable outward so as to interrupt the electrical path; and a load transmission portion placed between the first displacement portion and the second displacement portion and configured to transmit displacement of the first displacement portion to the second displacement portion.