Seam Welding Structure of Battery Can, Current Collecting Plate, and Cap and Battery Cell Using the Same

A battery cell includes: a can with an electrode assembly received therein, in which the can has a bottom member, a sidewall member connected to the bottom member and extending upwardly therefrom in an axial direction, and a cap covering an open end of the can at an axial end opposite to the bottom member. A current collector plate is connected to an electrode tab of the electrode assembly proximate the open end. The current collector plate includes: a central portion electrically connected to the electrode tab and a peripheral portion in electrical contact with a radially inner surface of the sidewall of the can. The peripheral portion is also in contact with an underside of the cap. The radially inner surface of the sidewall member, a radially outer surface of the cap, and the peripheral portion of the current collector plate are all welded to one another.