A battery according to various embodiments of the present disclosure may comprise: a negative-electrode substrate formed to have a first length in a first direction and to have a second length larger than the first length in a second direction, comprising the first coating portion being coated with a negative-electrode active material, and a first uncoated portion arranged adjacent to the first coating portion; a positive-electrode substrate formed to have a third length in the first direction and to have a fourth length larger than the third length in the second direction, comprising the second coating portion being arranged to face the negative-electrode substrate and coated with a positive-electrode active material, and a second uncoated portion arranged adjacent to the second coating portion; and a separator arranged between the negative-electrode substrate and the positive-electrode substrate. The first coating portion of the negative-electrode substrate and the second coating portion of the positive-electrode substrate may comprise multiple notches recessed from the outside to the inside thereof along the second direction and arranged at a designated interval so as to form a structure in which at least a part of a roll-shaped corner portion is cut, the corner portion being obtained by winding the negative-electrode substrate, the positive-electrode substrate, and the separator together.