Abstract:
The invention relates to a battery cell ( 2 ), comprising a prismatically designed cell housing ( 3 ) with a cover surface ( 31 ), on which a negative terminal ( 11 ) and a positive terminal ( 12 ) are arranged, and at least one electrode coil ( 10 ) which is arranged inside the cell housing ( 3 ) and comprises a cathode ( 14 ) having cathode contact lugs ( 24 ) and an anode ( 16 ) having anode contact lugs ( 26 ). The cathode contact lugs ( 24 ) and the anode contact lugs ( 26 ) extend next to one another from the electrode coil ( 10 ) toward exactly one end face ( 35, 36 ) of the cell housing ( 3 ), the end face ( 35, 36 ) running at a right angle to the cover surface ( 31 ). The invention also relates to a battery system comprising at least one battery cell ( 2 ) according to the invention.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a battery cell comprising a prismatically-designed cell housing having a cover surface, on which a negative terminal and a positive terminal are arranged, and at least one electrode coil arranged within the cell housing and having a cathode, which has cathode contact lugs, and having an anode, which has anode contact lugs. The invention also relates to a battery system comprising at least one battery cell according to the invention. 
         [0002]    It is evident that, in the future, whether in stationary applications such as wind turbine installations, in motor vehicles which are configured as hybrid vehicles or electric vehicles, or in electronic devices such as laptop computers or mobile phones, new battery systems will be employed which will be subject to very stringent requirements with respect to reliability, safety, performance capability and service life. 
         [0003]    So-called Lithium-ion battery cells are specifically employed for this purpose. These are characterized, amongst other features, by high energy densities, thermal stability and extremely low self-discharge capability. Lithium-ion battery cells have a positive and a negative electrode upon which, during a charging process and also during a discharging process, lithium ions can be reversibly deposited and also released again. A process of this type is also described as intercalation/deintercalation. 
         [0004]    In general, a battery cell comprises one or more electrode units, which are configured in the form of a coil. An electrode unit incorporates two foil-type electrodes, namely an anode and a cathode. The electrodes are wound, with the interposition of a separator, to form an electrode coil, which is also described as a jelly-roll. The two electrodes in the electrode coil are electrically connected to the poles of the battery cell, which are also described as terminals, by means of collectors. 
         [0005]    A battery cell further comprises a cell housing which is comprised, for example, of aluminum. The cell housing is generally configured as a prism, specifically as a cuboid, and is of pressure-resistant design. Further to the connection of the electrodes to the terminals, the cell housing is filled with an electrolyte solution. 
         [0006]    A generic battery cell with an electrode coil is known from EP 2 675 000 A1. The anode and the cathode project from opposing sides of the electrode coil, parallel to the winding axis, and are each connected to a collector. The two collectors are oriented essentially perpendicularly to the winding axis of the electrode coil, and connect the anode and the cathode to the terminals. 
         [0007]    A further generic battery cell is known from US 2010/0028770 A1. The electrodes of the electrode coil have contact lugs which project from the electrode coil and are connected to collectors. Prior to the connection with the collectors, the contact lugs are of different lengths. 
         [0008]    For the electrical insulation of the electrodes and the cell housing, insulators are provided which are, for example, of plastic construction. An electrode coil with corresponding insulators for a battery cell is disclosed in US 2013/0288092 A1. 
         [0009]    Lithium-ion battery cells are relatively sensitive to environmental influences, specifically to air and humidity. The aforementioned cell housing provides protection against said environmental influences. A plurality of such battery cells can be combined to form a battery system, which is also described as a battery pack. 
       SUMMARY OF THE INVENTION 
       [0010]    A battery cell is proposed, comprising a prismatically-designed cell housing having a cover surface, on which a positive terminal and a negative terminal are arranged. The battery cell further comprises at least one electrode coil arranged within the cell housing and having an anode, which has anode contact lugs, and having a cathode, which has cathode contact lugs. 
         [0011]    According to the invention, the anode contact lugs and the cathode contact lugs extend adjacently from the electrode coil toward precisely one end surface of the cell housing, wherein the end surface is oriented at right-angles to the cover surface. The anode contact lugs and the cathode contact lugs therefore extend toward the same end surface of the cell housing. In this case, the terminals are fitted to a different side of the cell housing, specifically to the cover surface. The end surface, toward which the anode contact lugs and the cathode contact lugs extend, adjoins the cover surface. 
         [0012]    The cell housing is preferably cuboid-shaped and has six sides with three different surface areas wherein, in each case, two of the six sides of equal surface area are situated opposite one another. The end surface, toward which the anode contact lugs and the cathode contact lugs extend, adjoins the cover surface in this case. 
         [0013]    The anode contact lugs and the cathode contact lugs advantageously extend toward the first end surface of the cell housing, wherein the first end surface and the second end surface, which is situated opposite the first end surface, have the smallest surface area of the sides of the cell housing. 
         [0014]    The cover surface, on which the terminals are arranged, and a base surface, which is situated opposite the cover surface, have an intermediate surface area of the sides of the cell housing in this case. 
         [0015]    According to an advantageous embodiment of the invention, the anode contact lugs or the cathode contact lugs are electrically connected to a collector which extends between the electrode coil and the base surface, and between the electrode coil and the second end surface. The collector is also electrically connected to one of the terminals in this case. 
         [0016]    According to a further advantageous embodiment of the invention, the anode contact lugs or the cathode contact lugs are electrically connected to a collector which extends between the electrode coil and a front surface. The front surfaces have the largest surface area of the sides of the cell housing in this case. The collector is also electrically connected to one of the terminals in this case. 
         [0017]    The cell housing is preferably of electrically-insulating design, for example composed of a plastic. 
         [0018]    The cell housing can also be of electrically-conductive design, for example composed of aluminum. 
         [0019]    In this case, the anode contact lugs or the cathode contact lugs are advantageously electrically connected to the electrically-conductive cell housing. If, in addition, one of the terminals is connected to the electrically-conductive cell housing, the collector can also be omitted. 
         [0020]    According to a further embodiment of the invention, an insulating film is provided between the cathode contact lugs and the anode contact lugs, which insulating film extends toward the end surface of the cell housing. 
         [0021]    The cathode and the anode are wound, with the interposition of at least one separator, to form the electrode coil. The insulating film is advantageously formed by the at least one separator in this case. 
         [0022]    A battery system is also proposed, comprising at least one battery cell according to the invention. 
         [0023]    A battery cell according to the invention can be advantageously employed in an electric vehicle (EV), a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV). 
         [0024]    In comparison to a battery cell known from the prior art in which the anode and the cathode project out of the electrode coil on opposite sides, the amount of space required for the collectors within the cell housing is advantageously reduced. The space additionally acquired in this way can be used for increasing the size of the electrode coil, as a result of which the capacity of the battery cell is increased given the same dimensions of the cell housing. The amount of space required for the collectors is also reduced in comparison to a battery cell in which the anode and the cathode project adjacently toward the cover surface on which the terminals are arranged. In the battery cell according to the invention, the collectors in the connection regions to the anode and to the cathode run on the same end surface which has the smallest surface area of the sides of a cuboid cell housing. Therefore, the collectors in the connection regions to the anode and to the cathode require the smallest possible volume. 
         [0025]    One of the two collectors is guided from said end surface directly to the adjacent cover surface to form one of the terminals. The other of the two collectors is guided around the electrode coil to form the other terminal. In this case, this collector is of comparatively thin design and takes up only a small volume on its way around the electrode coil. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    Forms of embodiment of the invention are described in greater detail, with reference to the drawings and the following description. 
           [0027]    Herein: 
           [0028]      FIG. 1  shows a schematic, perspective and semi-transparent representation of a battery cell, without collectors, 
           [0029]      FIG. 2  shows a schematic, perspective and semi-transparent representation of a battery cell according to a first form of embodiment, without electrode coil, 
           [0030]      FIG. 3  shows a schematic, perspective and semi-transparent representation of a battery cell according to a second form of embodiment, without electrode coil, 
           [0031]      FIG. 4  shows an overhead view of an end face of an electrode coil, prior to installation in a cell housing, 
           [0032]      FIG. 5 a    shows a partial sectional representation of the electrode coil represented in  FIG. 4 , along the section line V-V, prior to connection with a collector, 
           [0033]      FIG. 5 b    shows the electrode coil represented in  FIG. 5 a   , after connection with the collector, 
           [0034]      FIG. 6 a    shows a variation of the electrode coil represented in  FIG. 5 a   , prior to connection with a collector, 
           [0035]      FIG. 6 b    shows the electrode coil represented in  FIG. 6 a   , after connection with the collector, 
           [0036]      FIG. 7  shows a schematic representation of the manufacture of an electrode coil, 
           [0037]      FIG. 8  shows a schematic sectional representation of a battery cell with a first form of embodiment of a holder for the electrode coil, 
           [0038]      FIG. 9  shows a schematic sectional representation of a battery cell with a second form of embodiment of a holder for the electrode coil, 
           [0039]      FIG. 10  shows a schematic sectional representation of a battery cell with a third form of embodiment of a holder for the electrode coil, and 
           [0040]      FIG. 11  shows a further variation of an electrode coil in a schematic perspective representation. 
       
    
    
     DETAILED DESCRIPTION 
       [0041]    A battery cell  2  comprises a cell housing  3 , which is configured as a prism and, in the present case, as a cuboid. In the present case, the cell housing  3  is of electrically-conductive design and is manufactured, for example, from aluminum. It is also conceivable that the cell housing  3  is manufactured to be non-electrically conducting, in particular from an electrically-insulating material, for example plastic, or is coated with an electrically-insulating material. 
         [0042]    The battery cell  2  comprises a negative terminal  11  and a positive terminal  12 . A voltage delivered by the battery cell  2  can be tapped-off via the terminals  11 ,  12 . Moreover, the battery cell  2  can also be charged via the terminals  11 ,  12 . 
         [0043]    The cuboid-shaped cell housing  3  of the battery  2  has six sides with three different surface areas wherein, in each case, sides of equal surface area are arranged in mutually-opposing pairs. The sides with the largest surface area are described hereinafter as the first front surface  33  and the second front surface  34 . The sides with the smallest surface area are described hereinafter as the first end surface  35  and the second end surface  36 . The remaining sides, of intermediate surface area, are described hereinafter as the cover surface  31  and the base surface  32 . 
         [0044]    The terminals  11 ,  12  are arranged, with a mutual spacing, on the cover surface  31  of the cell housing  3 . The negative terminal  11  is arranged adjacently to the first end surface  35 , and the positive terminal  12  is arranged adjacently to the second end surface  36 . Insulators can be provided between the terminals  11 ,  12  and the cover surface  31 . 
         [0045]    Within the cell housing  3  of the battery cell  2 , an electrode coil  10  is arranged, which comprises two electrodes, namely a cathode  14  and an anode  16 . The cathode  14  and the anode  16  are configured as foil-type electrodes and, with the interposition of a first separator  18  and a second separator  19 , are wound around a winding axis A of the electrode coil  10 . The electrode coil  10  is arranged in the cell housing  3  such that the winding axis A is oriented perpendicularly to the end surfaces  35 ,  36 . 
         [0046]    It is also conceivable that the battery cell  2  comprises a plurality of electrode coils  10  which are electrically connected in parallel or, in the presence of sufficient insulation, in series. Moreover, an electrolyte is present within the cell housing  3 . 
         [0047]    The anode  16  has a plurality of anode contact lugs  26 , which are electrically connected to the negative terminal  11  of the battery cell  2 . The cathode  14  has a plurality of cathode contact lugs  24 , which are electrically connected to the positive terminal  12  of the battery cell  2 . The anode contact lugs  26  and the cathode contact lugs  24  project out adjacently from the electrode coil  10  on the same end surface, and extend from the electrode coil  10  to the first end surface  35  of the cell housing  3 . 
         [0048]    For the electrical connection of the anode  16  to the negative terminal  11 , a first collector  41  is provided. The first collector  41  has a first region  42 , which is oriented in parallel with the first end surface  35  and adjacent to the first end surface  35 , and is connected to the anode contact lugs  26  of the anode  16 . The first region  42  of the first collector  41  extends to the cover surface  31 , and forms a transition to a second region  43 , which is oriented in parallel with the cover surface  31 . The second region  43  of the first collector  41  is connected to the negative terminal  11 . Electrical insulators are provided between the first collector  41  and the cell housing  3  of the battery cell  2 . 
         [0049]    For the electrical connection of the cathode  14  to the positive terminal  12 , a second collector  51  is provided. The second collector  51  has a first region  52 , which is oriented in parallel with the first end surface  35  adjacent to the first end surface  35 , and is connected to the cathode contact lugs  24  of the cathode  14 . The second collector  51  has a second region  53 , which is connected to the positive terminal  12 . 
         [0050]    According to a first form of embodiment of the battery cell  2 , which is represented in  FIG. 2 , the second collector  51  has a central region  55 , which is connected to the first region  52  and to the second region  53 . The central region  55  of the second collector  51  extends in parallel with the front surfaces  33 ,  34 . In the present case, the central region  55  of the second collector  51  is arranged between the electrode coil  10  and the first front surface  33 . Electrical insulators are provided between the second collector  51  and the cell housing  3  of the battery cell  2 . 
         [0051]    The central region  55  of the second collector  51  can also be arranged between the electrode coil  10  and the second front surface  34 . Two parallel-oriented central regions  55  of the second collector  51  can also be provided, which are arranged on either side of the electrode coil  10 . 
         [0052]    According to a second form of embodiment of the battery cell  2 , which is represented in  FIG. 3 , the second collector  51  has a lower region  56 , which is connected to the first region  52 . The second collector  51  moreover has a rear region  57 , which is connected to the second region  53 . The lower region  56  of the second collector  51  is connected to the rear region  57  of the second collector  51 . 
         [0053]    The lower region  56  of the second collector  51  extends from the first region  52  of the second collector  51 , in parallel with the base surface  32  between the electrode coil  10  and the base surface  32 , to the second end surface  36 . The rear region  57  of the second collector  51  extends from the second region  53  of the second collector  51 , in parallel with the second end surface  36  between the electrode coil  10  and the second end surface  36 , to the base surface  32 . The rear region  57  of the second collector  51  is further connected to the lower region  56  of the second collector  51 . Electrical insulators are likewise provided between the second collector  51  and the cell housing  3  of the battery cell  2 . 
         [0054]    According to a further form of embodiment of the battery cell  2 , which is not represented here, the electrically-conductive cell housing  3  is electrically connected to the positive terminal  12 . In this case, no insulator is required between the second collector  51  and the cell housing  3 . 
         [0055]    It is moreover conceivable for the positive terminal  12  and the cathode contact lugs  24  of the cathode  14  to be electrically connected to the cell housing  3 . In this case, the cell housing  3  would assume the function of the second collector  51 , namely the electrical connection of the cathode  14  to the positive terminal  12 . In this case, the second collector  51  could be entirely omitted. It is also conceivable that the second collector  51  electrically connects the cathode contact lugs  24  of the cathode  14  to the first end surface  35  of the cell housing  3 . 
         [0056]      FIG. 4  shows an overhead view of an end surface of the electrode coil  10 , prior to the installation in the cell housing  3  of the battery cell  2 . The anode contact lugs  26  of the anode  16  project out of the electrode coil  10  in a near-parallel orientation to the winding axis A. The anode contact lugs  26  of the anode  16  are mutually aligned on a line in a direction which is perpendicular to the winding axis A. The cathode contact lugs  24  of the cathode  14  project out of the electrode coil  10  in a near-parallel orientation to the winding axis A. The cathode contact lugs  24  of the cathode  14  are mutually aligned on a line in a direction which is perpendicular to the winding axis A. 
         [0057]      FIG. 5 a    shows a partial sectional representation of the electrode coil  10  represented in  FIG. 4 , along the section line V-V. The part of the electrode coil  10  which incorporates the cathode contact lugs  24  of the cathode  14 , prior to connection with the second collector  51 , is represented. The second collector  51  is oriented perpendicularly to the winding axis A of the electrode coil  10 . 
         [0058]    The individual cathode contact lugs  24  of the cathode  14  are of different lengths. The cathode contact lug  24  which is facing the winding axis A is of the shortest length. The length of the cathode contact lugs  24  increases as the clearance of said cathode contact lugs  24  from the winding axis A increases. The cathode contact lug  24  which is averted from the winding axis A is of the longest length. 
         [0059]      FIG. 5 b    shows the electrode coil  10  represented in  FIG. 5 a   , after connection with the second collector  51 . The individual cathode contact lugs  24  of the cathode  14  are each curved around an axis which is oriented perpendicularly to the winding axis A, and are arranged one on top of another. The cathode contact lug  24  of the cathode  14  which is averted from the winding axis A is in contact with the second collector  51 . The cathode contact lugs  24  of the cathode  14  are interconnected, and are connected to the second collector  51 , specifically by welding. 
         [0060]    The lengths of the individual cathode contact lugs  24  of the cathode  14  are mutually tailored, such that the ends of the cathode contact lugs  24  which are averted from the electrode coil  10  converge with each other, after the connection of the cathode contact lugs  24  with the second collector  51 . 
         [0061]      FIG. 6 a    shows a variation of the electrode coil  10  represented in  FIG. 5 a   , prior to 
         [0062]    connection with the second collector  51 . The second collector  51  is oriented in parallel with the winding axis A of the electrode coil  10 . 
         [0063]    In said variation of the electrode coil  10 , the individual cathode contact lugs  24  of the cathode  14  are of different lengths. The cathode contact lug  24  which is facing the winding axis A and the second collector  51  is of the shortest length. The length of the cathode contact lugs  24  increases as the clearance of said cathode contact lugs  24  from the winding axis A and from the second collector  51  increases. The cathode contact lug  24  which is averted from the winding axis A and from the second collector  51  is of the longest length. 
         [0064]      FIG. 6 b    shows the electrode coil  10  represented in  FIG. 6 a   , after connection with the second collector  51 . The individual cathode contact lugs  24  of the cathode  14  are arranged one on top of another. The cathode contact lug  24  of the cathode  14  which is averted from the winding axis A is in contact with the second collector  51 . The cathode contact lugs  24  of the cathode  14  are interconnected, and are connected to the second collector  51 , specifically by welding. 
         [0065]    In said variation of the electrode coil  10 , the lengths of the individual cathode contact lugs  24  of the cathode  14  are mutually tailored, such that the ends of the cathode contact lugs  24  which are averted from the electrode coil  10  converge with each other, after the connection of the cathode contact lugs  24  with the second collector  51 . 
         [0066]      FIG. 7  shows a schematic representation of the manufacture of the electrode coil  10 . A winding core  65  is rotated around an axis of rotation D. A cathode  14  of foil-type design, a first separator  18  of foil-type design, an anode  16  of foil-type design and a second separator  19  of foil-type design are attached to the winding core  65 . The axis of rotation D of the winding core  65  is aligned with the winding axis A of the electrode coil  10 . 
         [0067]    By the rotation of the winding core  65 , the cathode  14 , the first separator  18 , the anode  16  and the second separator  19  are wound onto the winding core  65 . One of the separators  18 ,  19  is thus arranged respectively between the cathode  14  and the anode  16 . 
         [0068]    A first laser beam  61  cuts off an edge region of the foil-type anode  16 . However, the anode contact lugs  26  of the anode  16  are set in place. After one full rotation of the winding core  65  respectively, one of the anode contact lugs  26  of the anode  16  is set in place. This ensures that the anode contact lugs  26  of the anode  16 , as represented in  FIG. 4 , are mutually aligned on a line. 
         [0069]    The length of the set anode contact lugs  26  of the anode  16  increases with each rotation. Thus, the anode contact lug  26  of the anode  16  which is facing the axis of rotation D and the winding axis A has the shortest length, and the anode contact lug  26  of the anode  16  which is averted from the axis of rotation D and from the winding axis A has the longest length. 
         [0070]    A second laser beam  62  cuts off an edge region of the foil-type cathode  14 . However, the cathode contact lugs  24  of the cathode  14  are set in place. After one full rotation of the winding core  65  respectively, one of the cathode contact lugs  24  of the cathode  14  is set in place. This ensures that the cathode contact lugs  24  of the cathode  14 , as represented in  FIG. 4 , are mutually aligned on a line. 
         [0071]    The length of the set cathode contact lugs  24  of the cathode  14  increases with each rotation. Thus, the cathode contact lug  24  of the cathode  14  which is facing the axis of rotation D and to the winding axis A has the shortest length, and the cathode contact lug  24  of the cathode  14  which is averted from the axis of rotation D and from the winding axis A has the longest length, as represented in  FIG. 5   a.    
         [0072]    Once the cathode  14 , the anode  16  and the separators  18 ,  19  are fully wound, the winding core  65  can be removed. The electrode coil  10  can then be gently compressed together, such that the void left by the absent winding core  65  is closed. 
         [0073]      FIG. 8  shows a schematic sectional representation of a battery cell  2  with a holder  70  according to a first form of embodiment for an electrode coil  10 . The collectors  41 ,  51  are not fully represented. 
         [0074]    The holder  70  according to a first form of embodiment is configured as a rectangular frame, and formed of a non-electrically-conductive material, specifically of a plastic. The holder  70  according to the first form of embodiment comprises a first long side  71  and a second long side  72 , which is oriented in parallel with the first long side  71 . The first long side  71  and the second long side  72  are interconnected at their ends by a first short side  73  and a second short side  74 . The first short side  73  and the second short side  74  are mutually parallel, and are oriented at right-angles to the long sides  71 ,  72 . 
         [0075]    The first long side  71  of the frame-type holder  70 , according to the first form of embodiment, is fastened to the cover surface  31  of the cell housing  3  of the battery cell  2 . From the ends of the first long side  71  of the holder  70 , according to the first form of embodiment, the first short side  73  and the second short side  74  project at right-angles from the cover surface  31  to the unrepresented base surface  32  of the cell housing  3 . The first short side  73  is thus oriented adjacently to the unrepresented first end surface  35  of the cell housing  3 , and the second short side  74  is oriented adjacently to the unrepresented second end surface  36  of the cell housing  3 . The second long side  72  is oriented adjacently to the unrepresented base surface  32  of the cell housing  3 . 
         [0076]    The electrode coil  10  is clamped in the frame-type holder  70  according to the first form of embodiment. The winding axis A of the electrode coil  10  is thus oriented in parallel with the long sides  71 ,  72  of the holder  70  according to the first form of embodiment. The anode  16  and the cathode  14  project from the electrode coil  10 , adjacent to the first short side  73  of the holder  70  according to the first form of embodiment. 
         [0077]    The first collector  41  of the battery cell  2  is electrically and mechanically connected to the negative terminal  11 . A first spacer  67  is arranged between the first collector  41  and the cover surface  31  of the cell housing  3 . The first spacer  67  is formed of a non-electrically-conductive material, specifically of a plastic, and electrically insulates the first collector  41  from the cover surface  31  of the cell housing  3 . The first spacer  67  is thus mechanically attached to the cover surface  31  on the interior of the cell housing  3 . 
         [0078]    The second collector  51  of the battery cell  2  is electrically and mechanically connected to the positive terminal  12 . A second spacer  68  is arranged between the second collector  51  and the cover surface  31  of the cell housing  3 . The second spacer  68  is formed of a non-electrically-conductive material, specifically of a plastic, and electrically insulates the second collector  51  from the cover surface  31  of the cell housing  3 . The second spacer  68  is thus mechanically attached to the cover surface  31  on the interior of the cell housing  3 . 
         [0079]    The first long side  71  of the holder  70  according to the first form of embodiment is mechanically connected to the first spacer  67  and to the second spacer  68 . The first long side  71  of the holder  70  according to the first form of embodiment, in the manner of a clip-on connection, is compressed into corresponding recesses in the spacers  67 ,  68 , and is retained therein in a form-fitting manner. It is also conceivable that the holder  70  according to the first form of embodiment is configured in a one-piece arrangement with the spacers  67 ,  68 . 
         [0080]      FIG. 9  shows a schematic sectional representation of a battery cell  2  with a holder  80  according to a second form of embodiment for an unrepresented electrode coil  10 . The collectors  41 ,  51  are not fully represented. 
         [0081]    The holder  80  according to the second form of embodiment is configured in the form of an at least substantially closed box, and is formed of a non-electrically-conductive material, specifically of a plastic. The holder  80  according to the second form of embodiment comprises a cover region  81  and a base region  82 . 
         [0082]    The cover region  81  of the holder  80  according to the second form of embodiment is fastened to the cover surface  31  of the cell housing  3  of the battery cell  2 . In the representation shown, the base region  82  is arranged with a clearance from the cover region  81 . The base region  82 , after connection of the unrepresented electrode coil  10 , is compressed against the cover region  81  and latches onto the cover region  81  in a form-fitting manner. The unrepresented electrode coil  10  is then surrounded by the holder  80  configured in the form of a box according to the second form of embodiment. 
         [0083]    The first collector  41  of the battery cell  2  is electrically and mechanically connected to the negative terminal  11 . A first spacer  67  is arranged between the first collector  41  and the cover surface  31  of the cell housing  3 . The first spacer  67  is formed of a non-electrically-conductive material, specifically of a plastic, and electrically insulates the first collector  41  from the cover surface  31  of the cell housing  3 . The first spacer  67  is thus mechanically attached to the cover surface  31  on the interior of the cell housing  3 . 
         [0084]    The second collector  51  of the battery cell  2  is electrically and mechanically connected to the positive terminal  12 . A second spacer  68  is arranged between the second collector  51  and the cover surface  31  of the cell housing  3 . The second spacer  68  is formed of a non-electrically-conductive material, specifically of a plastic, and electrically insulates the second collector  51  from the cover surface  31  of the cell housing  3 . The second spacer  68  is thus mechanically attached to the cover surface  31  on the interior of the cell housing  3 . 
         [0085]    The cover region  81  of the holder  80  according to the second form of embodiment is mechanically connected to the first spacer  67  and to the second spacer  68 . The cover region  81  comprises clips which, in the manner of a clip-on connection, are compressed into corresponding recesses in the spacers  67 ,  68 , and are retained therein in a form-fitting manner. It is also conceivable that the cover region  81  is configured in a one-piece arrangement with the spacers  67 ,  68 . 
         [0086]      FIG. 10  shows a schematic sectional representation of a battery cell  2  with a holder  90  according to a third form of embodiment for an unrepresented electrode coil  10 . The collectors  41 ,  51  are not fully represented. 
         [0087]    The holder  90  according to the third form of embodiment is configured as a rectangular planar object, and is formed of a non-electrically-conductive material, specifically of a plastic. The holder  90  according to the third form of embodiment is delimited by a top side  91 , a base side  92  which is oriented in parallel with the top side  91 , a first outer side  93  and a second outer side  94 . The first outer side  93  and the second outer side  94  are oriented in a mutually parallel arrangement, and at right-angles to the top side  91  and the base side  92 . 
         [0088]    The top side  91  of the holder  90  according to the third form of embodiment is fastened to the cover surface  31  of the cell housing  3  of the battery cell  2 . The first outer side  93  and the second outer side  94  project at right-angles from the cover surface  31  to the unrepresented base surface  32  of the cell housing  3 . The first outer side  93  is thus oriented adjacently to the unrepresented first end surface  35  of the cell housing  3 , and the second outer side  94  is oriented adjacently to the unrepresented second end surface  36  of the cell housing  3 . The base side  92  is oriented adjacently to the unrepresented base surface  32  of the cell housing  3 . 
         [0089]    The unrepresented electrode coil  10  is wound around the holder  90  according to the third form of embodiment. The winding axis A of the electrode coil  10  is thus oriented at right-angles to the top side  91  of the holder  90  according to the third form of embodiment, and at right-angles to the cover surface  31  of the cell housing  3 . The anode  16 , the cathode  14  and the separators  18 ,  19  are thus arranged around the outer sides  93 ,  94  of the holder  90  according to the third form of embodiment. 
         [0090]    The first collector  41  of the battery cell  2  is electrically and mechanically connected to the negative terminal  11 . A first spacer  67  is arranged between the first collector  41  and the cover surface  31  of the cell housing  3 . The first spacer  67  is formed of a non-electrically-conductive material, specifically of a plastic, and electrically insulates the first collector  41  from the cover surface  31  of the cell housing  3 . The first spacer  67  is thus mechanically attached to the cover surface  31  on the interior of the cell housing  3 . 
         [0091]    The second collector  51  of the battery cell  2  is electrically and mechanically connected to the positive terminal  12 . A second spacer  68  is arranged between the second collector  51  and the cover surface  31  of the cell housing  3 . The second spacer  68  is formed of a non-electrically-conductive material, specifically of a plastic, and electrically insulates the second collector  51  from the cover surface  31  of the cell housing  3 . The second spacer  68  is thus mechanically attached to the cover surface  31  on the interior of the cell housing  3 . 
         [0092]    The top side  91  of the holder  90  according to the third form of embodiment is mechanically connected to the first spacer  67  and to the second spacer  68 . The top side  91  of the holder  90  according to the third form of embodiment, in the manner of a clip-on connection, is compressed into corresponding recesses in the spacers  67 ,  68 , and is retained therein in a form-fitting manner. It is also conceivable that the holder  90  according to the third form of embodiment is configured in a one-piece arrangement with the spacers  67 ,  68 . 
         [0093]    A further variation of an electrode coil  10  is shown in a schematic perspective representation in  FIG. 11 . The cathode contact lugs  24  of the cathode  14  and the anode contact lugs  26  of the anode  16  project out adjacently from the electrode coil  10  on the same end side. The anode contact lugs  26  of the anode  16  and the cathode contact lugs  24  of the cathode  14  project out of the electrode coil  10  in a near-parallel orientation to the winding axis A in this case. 
         [0094]    Between the cathode contact lugs  24  and the anode contact lugs  26 , parts of the first separator  18  and of the second separator  19  project out of the electrode coil  10  on the same end side in this case. In this case, said parts of the first separator  18  and of the second separator  19  extend parallel with the cathode contact lugs  24  and the anode contact lugs  26  and with the winding axis A toward the first end surface  35  of the cell housing  3 . 
         [0095]    The parts of the first separator  18  and of the second separator  19 , which parts project out of the electrode coil  10 , serve as an insulating film  21  in this case and electrically insulate the cathode contact lugs  24  of the cathode  14  from the anode contact lugs  26  of the anode  16 . 
         [0096]    The invention is not limited to the exemplary embodiments described and the aspects highlighted therein. Rather, within the scope indicated by the claims, a plurality of variations are possible, which lie within the practice of a person skilled in the art.