A sealed battery cell includes: a coiled electrode group comprising a positive electrode, a negative electrode, and a separator wound around a winding core; a cylindrical battery cell container having an open end and a bottom surface, that contains the coiled electrode group; and a sealed cover swaged in the open end of the battery cell container, which seals the open end; wherein the winding core is squeezed between the bottom surface of the battery cell container and the sealed cover, the bottom surface of the battery cell container being elastically deformed outwards in the axial direction.