A battery cell includes: a housing, wherein an opening is provided at an end portion of the housing; an electrode assembly arranged inside the housing, the electrode assembly including an electrode body and a first tab, the first tab being leaded from one end of the electrode body; an end cap closing the opening, the outer periphery of the end cap being fixed to the housing by welding; and a conductive piece located between the electrode assembly and the end cap, the conductive piece being electrically connected to the first tab, the conductive piece being electrically connected to at least one of the end cap and the housing, and an outer edge of the conductive piece extending at a position close to a welding region.