A battery cell includes an electrode assembly and a battery case. The electrode assembly includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. The battery case includes an upper case and a lower case, at least one of the upper case and the lower case being provided with a receiving part, in which the electrode assembly is mounted. One end of each of electrode tabs extending from electrode plates of the electrode assembly is coupled to a corresponding end of an electrode lead, which protrudes outward from the battery case. The electrode lead is provided with at least one notch part configured to rupture in response to expansion deformation of the battery case when the pressure in the battery cell increases to achieve the electrical cutoff of the battery.