Safety vent device used in a battery module

摘要

A sealed rechargeable battery module wherein a safety vent device is provided to release the internal pressure of the battery when the pressure has reached a predetermined value. The safety vent device includes a valve case formed with a vent and a sealing protrusion surrounding this vent. A valve body inserted in the valve case includes a sealing portion that is brought in tight contact with the sealing protrusion, a rigid holder for supporting the sealing portion, a and a resilient portion for pressing the rigid holder toward the vent. A valve cover is formed with apertures for closing the upper open end of the valve case. In a state, the resilient portion of the valve body is compressed.