A battery cell (200, 300) comprising: two or more electrode groups (210, 310, 320) having a structure in which electrodes including a positive electrode (10, 100), a negative electrode, and a separator interposed between the positive electrode (10, 100) and the negative electrode are stacked, wherein each of the electrode groups (210, 310, 320) includes an electrode tab junction (211, 221, 311, 321) on one side, and includes a first welding junction (231, 241, 331, 341) in which an end of the electrode tab junction (211, 221, 311, 321) is directly coupled to an electrode lead (250, 350) drawn to an outside of the battery case (201, 301), and wherein a conductive connecting member (230, 240, 330, 340) is coupled to the electrode lead (250, 350) and the electrode tab junction (211, 221, 311, 321) at the opposite surface of the first welding junction (231, 241, 331, 341) by a second welding junction (232, 242, 332, 342), the first welding junction (231, 241, 331, 341) having a structure in which a part of the electrode tab junction (211, 221, 311, 321) is coupled to the electrode lead (250, 350) in a bent state, the conductive connecting member (230, 240, 330, 340) having a structure in which the second welding junction (232, 242, 332, 342) is formed to be in a bent state corresponding to the electrode tab junction (211, 221, 311, 321) and a shape of the outer surface of the electrode lead (250, 350), the electrode groups being composed of a first electrode group (210, 310, 320) and a second electrode group (220, 320), the first electrode group and the second electrode group being arranged symmetrically with respect to the electrode lead (250, 350), and in the electrodes forming each of the electrode groups, bent angles of an electrode non-coated part extending from an end of an active material coated part to the electrode tab junction (211, 221, 311, 321) being symmetrical with respect to a horizontal axis passing through the center of the electrode group (210, 310, 320). two or more electrode groups (210, 310, 320) having a structure in which electrodes including a positive electrode (10, 100), a negative electrode, and a separator interposed between the positive electrode (10, 100) and the negative electrode are stacked, wherein each of the electrode groups (210, 310, 320) includes an electrode tab junction (211, 221, 311, 321) on one side, and includes a first welding junction (231, 241, 331, 341) in which an end of the electrode tab junction (211, 221, 311, 321) is directly coupled to an electrode lead (250, 350) drawn to an outside of the battery case (201, 301), and wherein a conductive connecting member (230, 240, 330, 340) is coupled to the electrode lead (250, 350) and the electrode tab junction (211, 221, 311, 321) at the opposite surface of the first welding junction (231, 241, 331, 341) by a second welding junction (232, 242, 332, 342), the first welding junction (231, 241, 331, 341) having a structure in which a part of the electrode tab junction (211, 221, 311, 321) is coupled to the electrode lead (250, 350) in a bent state, the conductive connecting member (230, 240, 330, 340) having a structure in which the second welding junction (232, 242, 332, 342) is formed to be in a bent state corresponding to the electrode tab junction (211, 221, 311, 321) and a shape of the outer surface of the electrode lead (250, 350), the electrode groups being composed of a first electrode group (210, 310, 320) and a second electrode group (220, 320), the first electrode group and the second electrode group being arranged symmetrically with respect to the electrode lead (250, 350), and in the electrodes forming each of the electrode groups, bent angles of an electrode non-coated part extending from an end of an active material coated part to the electrode tab junction (211, 221, 311, 321) being symmetrical with respect to a horizontal axis passing through the center of the electrode group (210, 310, 320).