DE102011089665A1 - Battery assembly, battery and manufacturing process - Google Patents

Abstract

The present invention discloses a battery assembly, in particular for a high-voltage battery for a motor vehicle, having at least one cell winding package having at least one cathode and one anode, with at least one first current conductor for a respective cell winding packet, said first current conductor is coupled to the cathode and a having flat formed contact surface, with at least a second current collector for a respective Zellwickelpaket, said second current collector is coupled to the anode and having a flat formed contact surface, with a first bus bar, which is coupled to the flat contact surface of the first current collector, and with a second bus bar, which is coupled to the flat contact surface of the second current collector. Further, the present invention discloses a battery and a manufacturing method.

Description

The present invention relates to a battery assembly, in particular for a high-voltage battery for a motor vehicle, a battery, in particular a high-voltage battery for a motor vehicle, and a manufacturing method for a battery assembly.

State of the art

Although the subject matter of the present invention may be used in a variety of applications in which electrical energy is stored, it will be described below in conjunction with hybrid and / or electric vehicles.

In the development of modern motor vehicles, the reduction of fuel consumption and thus of pollutant emissions is one of the most important criteria for the development engineer. In addition to reducing the weight of a motor vehicle, different drive types are combined in modern motor vehicles in order to further reduce the fuel consumption of a motor vehicle.

One possibility is to use an internal combustion engine, e.g. in hybrid vehicles, supplemented by an electric motor. Further, in electric vehicles, the engine is not only assisted by an electric motor but replaced by the electric motor.

In order to operate an electric motor in a motor vehicle, an energy storage is necessary. Such energy storage, e.g. a high-voltage battery, provides the electrical energy necessary to drive the electric motor and stores energy generated by the electric motor in generator operation, e.g. when the vehicle brakes, is won. High-voltage batteries usually consist of individual electrochemical energy storage cells, which can be electrically connected in series or in parallel.

Such energy storage for hybrid or electric vehicles is for example in the DE 10 2010 028 191 (A1) shown.

Usual energy storage cells each have at least one cell winding package whose cathode and anode are each contacted by means of a connecting wire, also called tab.

Disclosure of the invention

The present invention discloses a battery assembly having the features of claim 1, a battery having the features of claim 9 and a manufacturing method for a battery assembly having the features of claim 10.

Accordingly, it is provided:
A battery assembly, in particular for a high-voltage battery for a motor vehicle, having at least one cell winding package which has at least one cathode and one anode, with at least one first current conductor for a respective cell winding packet, said first current conductor is coupled to the cathode and having a flat contact surface , at least one second current conductor for a respective cell winding package, said second current collector being coupled to the anode and having a flat contact surface, and a first busbar coupled to the areal contact surface of the first current collector and a second Busbar, which is coupled to the flat contact surface of the second current collector.

A battery, in particular a high-voltage battery for a motor vehicle, having a battery housing, with at least one battery arrangement according to the invention, which is arranged in the battery housing, with a positive battery terminal, which is coupled to a first busbar of the battery assembly, and with a negative battery terminal, which with a second busbar, the battery assembly is coupled.

A manufacturing method for a battery assembly, in particular for a high-voltage battery for a motor vehicle, comprising the steps of arranging at least one cathode and an anode to form a cell winding package, coupling a first current conductor having a flat contact surface with the cathode, coupling a second current conductor a flat formed contact surface, with the anode, coupling a first bus bar with the area formed contact surface of the first Stromableiters, and coupling a second bus bar with the flat contact surface of the second Stromableiters.

Advantages of the invention

The finding underlying the present invention is that the inductance, which has a battery, in particular a high-voltage battery for a motor vehicle, depends on the geometry of the cell winding packages and their connections.

The idea underlying the present invention is now to take this knowledge into account and to provide a battery arrangement in which the paths which the electric current travels and those of which travel Paths enclosed areas are minimized.

If battery arrangements according to the invention are used, in addition to the low inductance, a low DC resistance also results.

The lower inductance and the lower DC resistance allow a reduction in the loss energy in switches or switching devices which are coupled to the battery assembly. Furthermore, the efficiency of the electrical system which is coupled to the battery assembly increases. Finally, electromagnetic emissions and DC losses are reduced.

Advantageous embodiments and further developments emerge from the dependent claims and from the description with reference to the figures.

In one embodiment, the cathode and the anode and the first current collector and the second current collector are formed as films. Further, the cell winding package has an insulating film and a separator film, and has the first current collector, the cathode, the separator film, the anode, the second current collector, and the insulating film stacked and wound in this order. This makes it possible to provide a stable battery assembly with a compact design.

In one embodiment, a battery arrangement has at least two cell winding packages, the battery arrangement being designed such that the contact area of the first current conductor and the contact area of the second current conductor of the cell winding packages are electrically coupled to the busbars in the same pole. The parallel connection of several battery arrangements makes it possible to easily increase the energy content of electrical energy which the battery arrangement has.

In one embodiment, a battery arrangement has at least two cell winding packages, the battery arrangement being designed such that the contact area of the first current conductor and the contact area of the second current conductor of at least two cell winding packages are electrically coupled to the busbars in opposite polarity. Furthermore, at least one busbar is electrically interrupted between the contact surfaces electrically coupled to the busbars. As a result, at least two Zellwickelpakete be connected in series. This makes it possible to adapt the output voltage of a battery assembly to different embodiments.

In a further embodiment, a battery arrangement has at least two cell winding packages, wherein the contact surface of the first current conductor and the contact surface of the second current conductor of at least two Zellwickelpaketen are electrically opposite polarity coupled to the busbars and the battery assembly additionally comprises at least two further Zellwickelpakete, wherein the contact surface of the first Stromableiters and the contact surface of the second Stromableiters the other cell winding packages are electrically gleichpolig coupled to the busbars. This makes it possible to adapt both the energy content, and the output voltage of the battery assembly to different requirements and conditions of use.

In one embodiment, the cell winding package has an elliptical or a semicircle connected with two sides, rectangular cross section. Furthermore, the first current conductor and the second current conductor are designed such that they protrude over the entire length of the major axis of the elliptical cross section of the cell wrapping package on opposite sides of the cell wrapping package across the width of the cell wrapping package, wherein the contact surfaces of the current conductor bent at right angles to the same End of the corresponding Stromableiters are formed. This makes it possible to arrange the busbars very close together and thus to reduce the inductance of both the current collector and the busbars.

In one embodiment, the cell winding package has an elliptical or a semicircle connected with two sides, rectangular cross section. Furthermore, the first current conductor and the contact area of the first current conductor and the second current conductor and the contact area of the second current conductor are formed as films of the cell winding package, wherein the contact surfaces of the current conductors are formed as foil sections unwound from the cell winding package. This makes it possible to arrange the busbars very close together and thus to reduce the inductance of both the current collector and the busbars. Furthermore, a very simple construction of the cell wrapping package is made possible, since no separate contact surfaces have to be provided.

In one embodiment, the cell winding package has an elliptical or a semicircle connected with two sides, rectangular cross section. Furthermore, the first current collector and the second current collector are designed such that they extend over the entire length of the major axis of the elliptical cross section of the cell wrapping packet on opposite sides of the cell wrapping packet across the width of the cell wrapping packet protrude, wherein the contact surfaces of the current conductor are angled at right angles formed at the same end of the respective Stromableiters and wherein the width of the busbars corresponds to the width of the Zwollwickelpakets and the busbars are arranged one above the other under the Zellwickelpaket, and depending on whether the first Busbar over the second busbar or the second busbar is disposed above the first busbar, the first current conductor is shorter than the second current collector or the second current collector shorter than the first current conductor is formed. This makes it possible to arrange the busbars very close together and thus to reduce the inductance of both the current collector and the busbars. In this arrangement, the bus bars may have an enlarged cross-section, thereby further reducing the DC resistance of the bus bars.

In one embodiment, the cell winding package has an elliptical or a semicircle connected with two sides, rectangular cross section. Furthermore, the first current conductor and the contact surface of the first conductor and the second conductor and the contact surface of the second conductor are formed as films of the Zwellwickelpakets, wherein the busbars are formed as voltage applied to side surfaces of the Zellwickelpakets busbars, and wherein the contact surfaces of the current collector as the side of the Cell winding packet formed tabs are formed. This makes it possible to place the cell winding packages very close together, thus providing a very compact battery arrangement.

The above embodiments and developments can, if appropriate, combine with each other as desired. Further possible refinements, developments and implementations of the invention also include combinations of features of the invention which have not been explicitly mentioned above or described below with regard to the exemplary embodiments. In particular, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the present invention.

Brief description of the drawings

The present invention will be explained in more detail with reference to the exemplary embodiments indicated in the schematic figures of the drawings. It shows:

1 a schematic representation of an embodiment of a battery assembly according to the invention 1 ;

2 a side view of an embodiment of a cell wrapping package according to the invention 2 ;

3 a schematic representation of another embodiment of a battery assembly according to the invention 1 ;

4 a schematic representation of another embodiment of a battery assembly according to the invention 1 ;

5 a schematic representation of another embodiment of a battery assembly according to the invention 1 ;

6 a block diagram of an embodiment of a battery according to the invention 14 ;

7 a flow diagram of a manufacturing method according to the invention.

In all figures, the same or functionally identical elements and devices - unless otherwise stated - have been given the same reference numerals.

Embodiments of the invention

1 shows a schematic representation of an embodiment of a battery assembly according to the invention 1 ,

The battery arrangement 1 in 1 has a cell wrapping package 2 on, which has an elliptical or a half-circles connected with two sides, rectangular cross-section, in which the ratio of major axis to minor axis is about 5: 1. In this case, the main axis of the elliptical cross-section forms in 1 the vertical axis of the cell wrapping package 2 , Further, the cell wrapping package 2 in 1 about twice as wide as it is wide. The individual layers of the cell wrapping package 2 are stacked and wound about an axis through the center of the elliptical cross section, so that in a side view of each side of the cell wrapping package, the individual layers are visible.

The cell wrapping package 2 has a first current collector on the left side 5 which, in one embodiment, has one at the cathode 3 adjacent current collector foil is electrically coupled. In a further embodiment, the first current conductor 5 integral with the current collector foil of the cathode 3 educated.

On the right side shows the Zellwickelpaket 2 a second current collector 7 which, in one embodiment, has one at the anode 4 adjacent current collector foil is electrically coupled. In a further embodiment, the second one Current conductor 7 integral with the current collector foil of the anode 4 educated.

The current collector 5 and 7 extend in each case over the entire length of the major axis of the elliptical cross section of the cell wrapping package 2 , At the bottom of the cell wrapping package 2 have the current collector 4 . 5 one contact surface each 6 . 8th on, which is perpendicular in a plane from the respective current conductor 4 . 5 towards the midpoint under the cell wrapping package 2 extends. In this case, the contact surface extends 6 of the first current conductor 5 only over a width of a first busbar 10 , The contact surface 8th of the second current collector 7 however, extends beyond the midpoint under the cell wrapping package to the contact surface 6 of the first current conductor 5 but without touching them. Under the contact surfaces 6 of the first current conductor 5 extends a first busbar 10 , which with the contact surface 6 is electrically coupled and which is marked with a "+". Under the contact surfaces 8th of the second current collector 7 extends a second busbar 11 , which with the contact surface 8th is electrically coupled and which is marked with a "-".

In further embodiments, in particular, the cell winding package 2 one from the cell wrapping package 2 in 1 deviating geometry. For example, the cell wrapping package 2 have a different aspect ratio or different external dimensions.

2 shows a side view of an embodiment of a Zellwickelpakets invention 2 ,

The cell wrapping package 2 in 2 indicates the first current conductor 5 , the cathode 3 , the separator film 12 , the anode 4 , the second current collector 7 and the insulator foil 13 stacked and wrapped in that order.

In an alternative embodiment, the cell wrapping package 2 the first current conductor 5 , the cathode 3 , the separator film 12 , the anode 4 , the second current collector 7 , a second second current collector 7 , a second anode 4 , a second separator film 12 , a second cathode 3 and a second first current collector 5 stacked and wrapped in that order.

In yet another embodiment, the cell wrapping package includes the cell wrapping package 2 the second current collector 7 , the anode 4 , the separator film 12 , the cathode 3 , the first current conductor 5 , a second first current collector 5 , the cathode 3 , a second separator film 12 , a second anode 4 and a second second current collector 7 stacked and wrapped in that order.

This will be the weight or volume fraction of the battery assembly 1 which has charge storage of the material increases.

In 2 is merely shown that the layers are once flipped up and then once wound from top to bottom. In further embodiments, a cell wrapping package 2 a multitude of turns on. The number of turns is at least of the available space and of the battery for the arrangement 1 specified energy content.

3 shows a schematic representation of another embodiment of a battery assembly according to the invention 1 ,

3 has a cell wrapping package 2 on which the cell wrapping package 2 of the 1 corresponds, but where the current collector 5 . 7 as Stromableiterfolien 5 . 7 in the cell wrapping package 2 are integrated. Further, in the cell wrapping package 2 in 3 an additional insulation layer 13b at the end of the cell wrap 2 arranged. In 3 forms as well as in 1 the major axis of the elliptical cross-section is the vertical axis of the cell wrapping package 2 ,

The cell wrapping package 2 does not have a separate current conductor 5 . 7 or contact surfaces 6 . 8th on. Rather, the contact surfaces 6 . 8th as part of the current collector foils 5 . 7 educated. To the current collector foils 5 . 7 with the busbars 10 . 11 Being able to contact electrically is the end of the cell wrapping package 2 so unwound that the unwound end on the busbars 10 and 11 comes to rest.

To the first current conductor 5 with the first busbar 10 To be able to contact the foils, which are between the first current conductor 5 and the first busbar 10 lie, cut out so that the first current conductor 5 directly on the first busbar 10 rests. Only the area of the foil is cut out, which is directly between the current conductor 5 and the first busbar 10 lies. By inserting the additional insulation layer 13b at the end of the coil ensures that cathode 3 and anode 4 are electrically isolated.

In an analogous manner, the films which are between the second current collector 7 and the second busbar 11 lie, cut out so that the second current conductor 7 directly on the second busbar 11 rests.

By the in 3 shown battery assembly 1 It becomes possible cell packing packages very easily with the busbars 10 . 11 connect to.

4 shows a schematic representation of another embodiment of a battery assembly according to the invention 1 ,

4 has a cell wrapping package 2 on which the cell wrapping package 2 of the 1 equivalent. Furthermore, the 4 Current conductor 5 . 7 on which as well as in 1 laterally on the cell wrapping package 2 are arranged.

In contrast to 1 but are the contact surfaces 6 . 8th the current conductor 5 . 7 not arranged on a common plane. In 4 are the busbars 10 . 11 such that they extend over the entire width of the cell wrapping package 2 extend. Furthermore, the busbars 10 . 11 arranged under the cell winding package with each other, wherein the first busbar 10 over the second busbar 11 is arranged. Further, in one embodiment, between the bus bars 10 . 11 one - in 4 not shown - insulating layer arranged to a short circuit between the busbars 10 . 11 to avoid.

For electrical contacting of the contact surfaces 6 . 8th the current conductor 5 . 7 are the current conductors 5 . 7 designed differently long. The contact surfaces 6 . 8th extend over the entire width of the cell wrapping package 2 , The contact surface 6 of the first current conductor 5 extends directly under the cell wrapping package 2 across the entire width of the cell wrapping package 2 and contacts the first busbar 10 , The second current collector 7 is formed so long that the contact surface 8th of the second current collector below the first busbar 10 is arranged to the second busbar 11 to contact.

5 shows a schematic representation of another embodiment of a battery assembly according to the invention 1 ,

The battery arrangement 1 in 5 has a cell wrapping package 2 on which the cell wrapping package 2 of the 1 equivalent. In contrast to 1 indicates the battery arrangement 1 in 5 no current conductors 5 . 7 on. The current collector 5 . 7 are in 5 as Stromableiterfolien 5 . 7 trained and in the Zellwickelpaket 2 integrated. The contact surfaces 6 . 8th the current collector foils 5 . 7 are as tabs 6 . 8th formed, which on each side of the cell wrapping package 2 are attached to the busbars 10 . 11 to contact. To electrically contact the busbars 10 . 11 with the tabs 6 . 8th to enable, are the busbars 10 . 11 on the sides of the cell wrapping package 2 arranged adjacent.

6 shows a block diagram of an embodiment of a battery according to the invention 14 ,

The battery 14 has a battery case 15 on which at least one battery assembly 1 having. In 6 are other possible battery arrangements 1 represented by three points. Furthermore, the battery points 14 in 6 a positive battery connection 16 and a negative battery connection 17 on which with the battery arrangements 1 are coupled.

7 shows a flowchart of a manufacturing method according to the invention.

In a first step S1 of the embodiment of the method, a first current conductor 5 which has a flat contact surface 6 comprising, with a cathode 3 coupled. In a second step S2, a second current collector 7 which has a flat contact surface 8th having, with the anode 4 coupled. In a third step S3, at least the cathode 3 , the anode 4 , a separator film 12 as well as the current collector 5 . 7 to a cell wrapping package 2 arranged. In a fourth step S4 becomes a first busbar 10 with the flat contact surface 6 of the first current conductor 5 coupled and in a fifth step S5 is a second busbar 11 with the flat contact surface 8th of the second current collector 7 coupled.

Although the present invention has been described above with reference to preferred embodiments, it is not limited thereto, but modifiable in a variety of ways. In particular, the invention can be varied or modified in many ways without deviating from the gist of the invention.

In one embodiment, the contact surfaces 6 . 8th with the busbars 10 . 11 be electrically and mechanically coupled by spot welding. In further embodiments, the contact surfaces 6 . 8th with the busbars 10 . 11 be electrically and mechanically coupled by electrically conductive adhesive, by soldering or the like.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010028191 A1 [0006]

Claims (10)

Battery arrangement ( 1 ), in particular for a high-voltage battery for a motor vehicle, with at least one cell winding package ( 2 ), which at least one cathode ( 3 ) and an anode ( 4 ) having; with at least one first current conductor ( 5 ) for a respective cell wrapping package ( 2 ), which is connected to the cathode ( 3 ), and which has a flat contact surface ( 6 ) having; with at least one second current conductor ( 7 ) for a respective cell wrapping package ( 2 ), which with the anode ( 4 ), and which has a flat contact surface ( 8th ) having; with a first busbar ( 10 ), which with the flat contact surface ( 6 ) of the first current conductor ( 5 ) is coupled; with a second busbar ( 11 ), which with the flat contact surface ( 8th ) of the second current collector ( 7 ) is coupled. Battery arrangement according to claim 1, characterized in that the cathode ( 3 ) and the anode ( 4 ) as well as the first current conductor ( 5 ) and the second current collector ( 6 ) are formed as films, and the cell winding package ( 2 ) a separator film ( 12 ) and an insulation film ( 13 ) having; and wherein the cell wrapping package ( 2 ) the first current conductor ( 5 ), the cathode ( 3 ), the separator film ( 12 ), the anode ( 4 ), the second current collector ( 7 ) and the insulating film ( 13 ) stacked and wound in this order; or wherein the cell wrapping package ( 2 ) the first current conductor ( 5 ), the cathode ( 3 ), the separator film ( 12 ), the anode ( 4 ), the second current collector ( 7 ), a second second current collector ( 7 ), a second anode ( 4 ), a second separator film ( 12 ), a second cathode ( 3 ) and a second first current conductor ( 5 ) having. Battery arrangement according to one of claims 1 and 2, characterized in that a battery arrangement ( 1 ) at least two cell wrapping packages ( 2 ) having; the battery arrangement ( 1 ) is formed such that the contact surface ( 6 ) of the first current conductor ( 5 ) and the contact area ( 8th ) of the second current collector ( 7 ) of the cell wrapping packages ( 2 ) electrically homopolar with the busbars ( 10 . 11 ) are coupled. Battery arrangement according to one of claims 1 and 2, characterized in that a battery arrangement ( 1 ) at least two cell wrapping packages ( 2 ) having; the battery arrangement ( 1 ) is formed such that the contact surface ( 6 ) of the first current conductor ( 5 ) and the contact area ( 8th ) of the second current collector ( 7 ) of at least two cell wrapping packages ( 2 ) electrically opposite pole with the busbars ( 10 . 11 ) are coupled; and wherein at least one busbar ( 10 . 11 ) between the electrical opposite pole with the busbars ( 10 . 11 ) coupled contact surfaces ( 6 . 8th ) is electrically interrupted. Battery arrangement according to one of the preceding claims 1 to 4, characterized in that the cell winding package ( 2 ) has an elliptical or one with two sides connected semicircles, rectangular cross-section; and that the first current conductor ( 5 ) and the second current conductor ( 7 ) are formed such that these over the entire length of the major axis of the elliptical cross-section of the cell winding package ( 2 ) on opposite sides of the cell wrapping package ( 2 ) across the width of the cell wrapping package ( 2 protrude; where the contact surfaces ( 6 . 8th ) the current conductor ( 5 . 7 ) at right angles angled at the respective same end of the corresponding Stromableiters ( 5 . 7 ) are formed. Battery arrangement according to one of the preceding claims 1 to 4, characterized in that the cell winding package ( 2 ) has an elliptical or one with two sides connected semicircles, rectangular cross-section; and that the first current conductor ( 5 ) and the contact surface ( 6 ) of the first current conductor ( 5 ) and the second current collector ( 7 ) and the contact area ( 8th ) of the second current collector ( 7 ) as films of the cell wrapping package ( 2 ) are formed; where the contact surfaces ( 6 . 8th ) the current conductor ( 5 . 7 ) than from the cell wrapping package ( 2 ) developed film sections are formed. Battery arrangement according to one of the preceding claims 1 to 4, characterized in that the cell winding package ( 2 ) has an elliptical or one with two sides connected semicircles, rectangular cross-section; and that the first current conductor ( 5 ) and the second current conductor ( 7 ) are formed so that they are formed over the entire length of the major axis of the elliptical cross-section of the cell wrapping package ( 2 ) on opposite sides of the cell wrapping package ( 2 ) across the width of the cell wrapping package ( 2 protrude; where the contact surfaces ( 6 . 8th ) the current conductor ( 5 . 7 ) angled at right angles to the same End of the corresponding current conductor ( 5 . 7 ) are formed; the width of the busbars ( 10 . 11 ) the width of the Zwollwickelpakets ( 2 ), and the busbars ( 10 . 11 ) lying one above the other under the cell wrapping package ( 2 ) are arranged; and depending on whether the first busbar ( 10 ) over the second busbar ( 11 ) or the second busbar ( 11 ) above the first busbar ( 10 ), the first current conductor ( 5 ) shorter than the second current conductor ( 6 ) or the second current collector ( 6 ) shorter than the first current conductor ( 5 ) is trained. Battery arrangement according to one of the preceding claims 1 to 4, characterized in that the cell winding package ( 2 ) has an elliptical or one with two sides connected semicircles, rectangular cross-section; and that the first current conductor ( 5 ) and the contact surface ( 6 ) of the first current conductor ( 5 ) and the second current collector ( 7 ) and the contact area ( 8th ) of the second current collector ( 7 ) as films of Zwollwickelpakets ( 2 ) are formed; the busbars ( 10 . 11 ) than on side surfaces of the cell wrapping package ( 2 ) adjacent busbars ( 10 . 11 ) are formed; and wherein the contact surfaces ( 6 . 8th ) the current conductor ( 5 . 7 ) as laterally on the cell wrapping package ( 2 ) formed tabs ( 6 . 8th ) are formed. Battery, in particular high-voltage battery for a motor vehicle, having a battery housing ( 15 ); with at least one battery arrangement ( 1 ) according to one of the preceding claims, which in the battery housing ( 15 ) is arranged; with a positive battery connection ( 16 ), which with a first busbar ( 10 ) of the battery arrangement ( 1 ) is coupled; and with a negative battery connection ( 17 ), which with a second busbar ( 11 ), the battery assembly ( 1 ) is coupled. Manufacturing method for a battery assembly ( 1 ), in particular for a high-voltage battery for a motor vehicle, comprising the following steps: coupling (S1) of a first current conductor ( 5 ), which has a flat contact surface ( 6 ), with a cathode ( 3 ); Coupling (S2) of a second current conductor ( 7 ), which has a flat contact surface ( 8th ), with an anode ( 4 ); and arranging (S3) at least the cathode ( 3 ), the anode ( 4 ), a separator film ( 12 ) as well as the current conductor ( 5 , 7) to a cell wrapping package ( 2 ); Coupling (S4) a first busbar ( 10 ) with the flat contact surface ( 6 ) of the first current conductor ( 5 ); Coupling (S5) a second busbar ( 11 ) with the flat contact surface ( 8th ) of the second current collector ( 7 ).

Images