SECONDARY BATTERY AND BATTERY MODULE

The present application relates to a secondary battery and a battery module. The secondary battery comprises: a casing, which is provided with an accommodating hole with an opening; a top cover assembly, which is in sealed connection with the casing to close the opening; an electrode assembly, which is arranged in the accommodating hole, and comprises two end faces opposite to a first direction perpendicular to an axial direction of the accommodating hole, and tabs extending from the end faces, the electrode assembly comprises two or more electrode units, wherein two or more electrode units are stacked in the axial direction, and in a second direction perpendicular to the axial direction and the first direction, the size of the tabs is smaller than that of the end faces; and a current collector, which comprises a body portion, wherein the body portion is at least partially arranged between the end faces and the casing, the body portion extends in the axial direction and is electrically connected with the tabs, and the body portion and the tabs are at least partially overlapped in the second direction. The body portion of the current collector in the secondary battery of the present application is arranged in parallel with the tabs, so that the occupancy rate of the space between the electrode units is reduced, which is beneficial to improve energy density.