A button cell closed without flanging includes a housing formed of two housing halves including a cell cup and a cell lid, an electrically insulating seal separating the cell cup and the cell lid, an electrode-separator assembly including at least one positive and at least one negative electrode arranged inside the housing, metal diverters electrically connecting the at least one positive and the at least one negative electrode to the housing halves, and a thermal fuse connected to or integrated into one of the diverters.