BATTERY CELL COMPRISING BATTERY CASE INCLUDING ACCOMMODATION PART AND ELECTRODE LEAD GROOVE

Disclosed in a battery cell including: an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes, with electrode tabs protruding from at least one side of outside peripheral portions of the electrode assembly; and a battery casing including first and second casings provided with first and second receiving parts, respectively, the first and second receiving parts respectively accommodating the electrode assemblies and having different sizes or shapes, wherein in a state in which electrode leads connected to the electrode tabs protrude from outside peripheral portions of the first and second casings, the battery casing is sealed by thermal fusion along the outside peripheral portions of the first and second casings, wherein electrode lead grooves recessed downwardly such that the electrode leads are seated therein are provided at a portion of the outside peripheral portions of the first and second casings.