BUTTON CELL AND PREPARATION METHOD THEREOF

A button cell and a preparation method thereof, where the button cell includes a housing and a roll core; the housing includes a housing body and a top cover assembly, the housing body and the top cover assembly jointly enclose an accommodating cavity for accommodating the roll core; the roll core includes a first tab and a second tab, and the first tab is connected with a bottom wall of the housing body by welding, and the second tab is connected with the top cover; the top cover is provided with an injection hole, the injection hole at least partially overlaps with a cavity of the roll core; a welding mark between the first tab and the bottom wall is located in a portion where the bottom wall overlaps with the cavity and the injection hole.