Safety element for battery and battery with the same

Disclosed is a battery safety device having a first metal plate, a second metal plate, and a pressure-sensitive conducting film interposed between both metal plates and adapted to exhibit electrical conductivity when a predetermined pressure or higher is applied. The first and second metal plates are electrically connected to the positive and negative electrodes of the battery, respectively. The safety device connected to a battery prevents the battery from being damaged or at least from igniting or exploding, even when an external impact caused by pressure, a nail, or a nipper or an external pressure is applied to the battery, by conducting the current of the battery to the safety device and discharging the battery before the battery is damaged by the external impact or external pressure.