The present invention relates to a safety switch of a secondary battery for an
electric vehicle and a
charge and discharge system of a secondary battery for an
electric vehicle using the same, and more particularly, to a technology capable of protecting a secondary battery by operating a switch of the secondary battery for the
electric vehicle attached to the outside of the secondary battery in order to disconnect a driving motor for the electric vehicle to the secondary battery when the secondary battery expands or excessive short-circuit current flows into circuits of the secondary battery, due to a swelling phenomenon of the second battery expanding due to an abnormal status of the secondary battery, such as
overcharge, heat
exposure, a
short circuit, a
reverse connection, or the like, in using the secondary battery for the electric vehicle.According to the present invention, there is provided a safety switch of a secondary battery for an electric vehicle, including: a
cutting member 110 attached to one surface of any one secondary battery 10 in the secondary battery for the electric vehicle configured by connecting at least two secondary batteries and having a
cutting body 112; and a
cut member 120 attached to one surface of the other secondary battery 20 while facing the
cutting member 110 including a
cut body 123 approaching the cutting body 112 of the cutting member 110 and
cut by the approaching cutting body 112 to electrically disconnect the secondary batteries, when the secondary batteries are expanded due to the swelling phenomenon.