Abstract: A safety valve mounted on a battery includes a main body which has a hollow structure formed so that a top communicates with a bottom and a discharge hole in one side surface of an upper portion, a sub body which is formed to protrude from an inner circumferential surface of the main body where a through hole is formed in one side surface of a lower portion of the sub body, a cap membrane of which a cross section has a “?” shape so that the cap membrane is in close contact with an upper portion of the sub body to close the upper portion of the sub body due to a weight of the cap membrane or moves upward from the upper portion of the sub body to open the upper portion of the sub body and which has a circular cap shape, and a cover which opens or closes the upper portion of the main body, and only one protrusion is formed on an inner circumferential surface of an end portion of the cap membrane.

Abstract: A safety valve mounted on a battery includes a main body which has a hollow structure formed so that a top communicates with a bottom and a discharge hole in one side surface of an upper portion, a sub body which is formed to protrude from an inner circumferential surface of the main body where a through hole is formed in one side surface of a lower portion of the sub body, a cap membrane of which a cross section has a “?” shape so that the cap membrane is in close contact with an upper portion of the sub body to close the upper portion of the sub body due to a weight of the cap membrane or moves upward from the upper portion of the sub body to open the upper portion of the sub body and which has a circular cap shape, and a cover which opens or closes the upper portion of the main body, and a protrusion is formed on an inner circumferential surface of an end portion of the cap membrane.

Abstract: A safety valve having a simple structure and a small operating pressure error and configured to maintain a constant pressure in a battery by effectively discharging gas in the battery is provided. A safety valve according to one aspect of the present invention, which is mounted on a battery and operates to maintain a predetermined internal pressure in the battery when the predetermined pressure or more is applied to the battery, includes a main body, a sub body, a cap membrane, and a cover, and a protrusion is formed on an end portion of the cap membrane to be in line contact with an outer surface of the sub body. The main body has a hollow structure formed so that a top communicates with a bottom and a discharge hole in one side surface of an upper portion. The sub body is formed to protrude from an inner circumferential surface of the main body, and a through hole is formed in one side surface of a lower portion of the sub body.