NOVELTY - Device to produce a single cell (8) for a battery, comprises an electrode stack (4), a pole (6), a housing side wall (3), a sonotrode (2), an anvil and a die, where each single cell is formed from the electrode stack and the individual electrodes with different polarity are separated from each other in an insulating manner by a separator, preferably a separator foil. The electrodes with the same polarity are connected together in an electrically conductive manner to the pole. The pole of each electrode stack is connected with an electrically conductive housing side wall.    USE - The battery is useful in a vehicle, preferably a hybrid vehicle or electric vehicle.    ADVANTAGE - The device: exhibits high electrical performance and life to obtain the single cell; comprises pole welded with the housing side walls which forms the electrical pole contact of the single cell and a firmly rigid connection between the pole and the housing side wall, thus exhibiting low contact resistance, good thermal conductivity and high current carrying capacity; produces single cells, which are directly in contact with the housing side walls, thus enabling for electrical connectivity of the single cells to produce the battery; and has less production time and low production cost.    DETAILED DESCRIPTION - Device to produce a single cell (8) for a battery, comprises an electrode stack (4), a pole (6), a housing side wall (3), a sonotrode (2), an anvil and a die, where each single cell is formed from an electrode stack and the individual electrodes with different polarity, preferably foil electrodes are separated from each other in an insulating manner by a separator, preferably a separator foil. The electrodes with the same polarity are connected together in an electrically conductive manner to a pole. The pole of each electrode stack is connected with an electrically conductive housing side wall in an electrically conductive manner by an ultrasonic welding device, comprising at least the sonotrode and the anvil. The anvil is formed as a molded die. INDEPENDENT CLAIMS are also included for:    (1) producing the single cell for a battery comprising arranging the housing side wall and the electrode stack in an interlocked manner in the anvil formed as the die and partially welding by the anvil and the sonotrode;    (2) the single cell produced by the device and by the above mentioned method, where the single cell is a bipolar frame flat cell; and    (3) a battery comprising a predetermined number of the single cells, where the single cells are formed by pressing together their housing side walls and two of the housing side walls contacted together exhibits different polarity and are electrically connected together in series.    DESCRIPTION OF DRAWING(S) - The figure shows a perspective view of the device with an inserted single cell.    Sonotrode (2)    Housing side wall (3)    Electrode stack (4)    Pole (6)    Single cell (8)