BUS BAR ASSEMBLY FOR ELECTRODE LEAD BONDING AND BATTERY MODULE INCLUDING SAME

Technology field
[1]
The present invention relates to a bus bar assembly for bonding electrode leads and a battery module including the same, and more particularly, to a bus bar assembly capable of being coupled to a bus bar without bending electrode leads and a battery module including the same.
[2]
This application is an application for claiming priority for Korean Patent Application No. 10-2017-0130918 filed on October 11, 2017, and all contents disclosed in the specification and drawings of the application are incorporated herein by reference.
Background
[3]
Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries have little memory effect compared to nickel-based secondary batteries, so charging and discharging are free and self-contained. It has a very low discharge rate and is in the spotlight for its high energy density.
[4]
The lithium secondary battery mainly uses a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively. The lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate to which the positive electrode active material and the negative electrode active material are respectively applied are disposed, and an exterior material that seals and stores the electrode assembly together with an electrolyte, that is, a battery case.
[5]
Generally, a lithium secondary battery may be classified into a can-type secondary battery in which the electrode assembly is embedded in a metal can and a pouch-type secondary battery in which the electrode assembly is embedded in a pouch of an aluminum laminate sheet, depending on the shape of the exterior material.
[6]
In recent years, secondary batteries are widely used not only in small devices such as portable electronic devices, but also in electric vehicles to secure driving power using an internal combustion engine and/or an electric motor. The electric vehicle includes a hybrid vehicle, a plug-in hybrid vehicle, and a pure electric vehicle driven only by an electric motor and a battery without an internal combustion engine.
[7]
When used in such an electric vehicle, a large number of secondary batteries are electrically connected to increase capacity and output. In particular, pouch-type secondary batteries are widely used in medium- to large-sized devices due to the advantage of easy stacking. Therefore, a battery module/pack of a medium-sized device is typically implemented through series and/or parallel connection of the pouch-type secondary batteries.
[8]
Meanwhile, when configuring the battery module, as shown in FIG. 1, the electrode leads 20 of the pouch-type secondary battery 10 are bent and contacted on the top surface of the bus bar, and then welded 40 to bond them. Here, the bus bar means a rod-shaped conductor made of a material such as copper, silver, or tin-plated copper. Such a bus bar can safely conduct a high-capacity current compared to a copper wire, and is thus widely used as a wiring member in a power supply device including a battery module of an electric vehicle.
[9]
However, in the case of the prior art, a number of manual operations by the operator are required to maintain the bending shape of the electrode leads 20, and the electrode leads 20 and the bus bar are There is a problem that (30) does not adhere well. In particular, when connecting three to four or more electrode leads in parallel, since a plurality of electrode leads must be superimposed on the bus bar, it is more difficult to perform welding, and in this case, there is a problem that the welding quality is also deteriorated.
Detailed description of the invention
Technical challenges
[10]
Accordingly, an object of the present invention is to provide a bus bar assembly capable of intimate contact between the electrode leads and the bus bar by coupling the electrode leads to a bus bar without bending the electrode leads, and a battery module including the same.
[11]
However, the technical problem to be achieved by the present invention is not limited to the above-described problems, and other problems that are not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.
Task resolution
[12]
According to the present invention, as a bus bar assembly for electrically connecting a plurality of battery cells having an electrode lead,
[13]
Insertion-type busbar provided in the form of a rod-shaped conductor; A side-contact type bus bar having the insertion type busbar in the center and forming a fitting space in which at least one electrode lead can be interposed on both sides of the insertion type busbar; And supporting the insert-type bus bar to a position protruding more than the side-adhesive bus bar. A busbar assembly may be provided that includes a supporting and holding member to be configured.
[14]
The support and holding member has both ends for supporting the insert-type busbar, is provided elastically to the left and right, and when the insert-type busbar is retracted into the inside, the plate presses both sides of the insert-type busbar with elastic restoring force It can be a spring.
[15]
The insertion-type busbar may have a tapered portion whose width gradually decreases so as to be inserted into the space between both ends of the leaf spring.
[16]
The insertion-type busbar includes a first flat portion facing the side surface of the side-contact busbar on the same plane as the side-contact busbar, and a width smaller than that of the first flat portion, and is formed by both ends of the leaf spring. A second flat portion to be pressed may be provided.
[17]
The side-adhesive busbars are provided to be mutually separable by pairing the two, each of which is provided in close contact with the insertion-type busbars, and a gap adjusting part that is formed to be bently extended at both ends of the closets. Including, it may be configured to surround the circumference of the insertion-type busbar is disposed symmetrically with each other in the center.
[18]
The plate-shaped structure may further include a bus bar support frame having a slit through which the electrode lead can pass at a position corresponding to the fitting space, and supporting the insertion type bus bar and the side contact type bus bar.
[19]
The busbar support frame may further include a clamping portion provided at a position opposite to the support and holding member with the insertable busbar interposed therebetween to restrain the insertable busbar.
[20]
The bus bar support frame may further include an elastic pressing portion provided to elastically press both sides of the side-contact type bus bar.
[21]
The bus bar support frame may further include a corner bracket portion provided to surround and support the four corner portions of the side-adhesive bus bar.
[22]
According to another aspect of the present invention, a battery module including the above-described bus bar assembly may be provided.
Effects of the Invention
[23]
According to the present invention, it is possible to provide a bus module and a battery module including the bus bar assembly capable of contacting the electrode leads and the bus bar by being coupled to the bus bar without bending the electrode leads.
[24]
In addition, since all electrode leads can be welded in a mechanically pressurized state, reliability of electrical connection and mechanical bonding strength can be improved regardless of the number of electrode leads in a parallel connection structure.
[25]
In addition, since a manual process for bending electrode leads is eliminated, the automation rate of the battery module production line may be improved.
[26]
The effects of the present invention are not limited to the above-described effects, and effects not mentioned will be clearly understood by those of ordinary skill in the art from the present specification and the accompanying drawings.
Brief description of drawings
[27]
1 is a diagram schematically showing a bonding configuration between an electrode lead and a bus bar according to the prior art.
[28]
2 and 3 are perspective views schematically showing a main configuration of a busbar assembly and a battery cell stack according to an embodiment of the present invention.
[29]
4 is a perspective view showing the configuration of a busbar assembly in a state before insertion of an electrode lead according to an embodiment of the present invention.
[30]
5 is a partial cut-away perspective view of FIG. 4.
[31]
6 is a perspective view showing the configuration of a busbar assembly in a state after inserting an electrode lead according to an embodiment of the present invention.
[32]
7 is a partial cut-away perspective view of FIG. 6.
[33]
8 and 9 are diagrams schematically showing a configuration before and after bonding of an electrode lead and a busbar assembly according to an embodiment of the present invention.
Mode for carrying out the invention
[34]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the present specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventors appropriately explain the concept of terms in order to explain their own invention in the best way. Based on the principle that it can be defined, it should be interpreted as a meaning and concept consistent with the technical idea of ​​the present invention.
[35]
Accordingly, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. It should be understood that there may be equivalents and variations.
[36]
Since the embodiments of the present invention are provided to more completely describe the present invention to a person skilled in the art, the shape and size of components in the drawings may be exaggerated, omitted, or schematically illustrated for clearer description. Therefore, the size or ratio of each component does not entirely reflect the actual size or ratio.
[37]
The busbar assembly 1 according to the present invention may mean an accessory of a battery module that electrically connects the electrode leads 20 of the plurality of battery cells 10. However, the scope of the present invention is not limited to the case where the battery module is used as a component. For example, the busbar assembly 1 of the present invention can be used as a wiring component in a power supply device including a battery module.
[38]
2 and 3 are perspective views schematically showing a main configuration of a bus bar assembly and a battery cell stack according to an embodiment of the present invention, and FIGS. 4 and 5 are inserting electrode leads according to an embodiment of the present invention A perspective view showing the configuration of the busbar assembly in its previous state and its main partial cut-away perspective view, and FIGS. 6 and 7 are perspective views showing the configuration of the busbar assembly in a state after insertion of an electrode lead according to an embodiment of the present invention, and Main partial cut-away perspective view.
[39]
Referring to these drawings, the busbar assembly 1 according to the present invention includes at least one electrode lead on both sides of the insertable busbar 100 with the insertable busbar 100 and the insertable busbar 100 in the center. 20) side-contacted busbar 200 forming a fitting space (S) that can be interposed, and the insertion-type busbar 100 are supported in a more protruding position than the side-contacted busbar 200, but the insertion-type bus A support and holding member 300 provided to be elastically deformable by the bar 100 and a bus bar support frame 400 providing a place where they can be assembled and supported may be included.
[40]
The electrode lead 20 of the battery cell 10 includes a positive lead 21 and a negative lead 22. As will be described later in detail, according to the present invention, the positive lead 21 and the negative lead 22 are directly inserted into the fitting space S of the bus bar assembly 1 according to the present invention, Welding may be performed after the end is clamped. Therefore, the electrode lead 20 is not required without a bending work process as in the prior art, thereby increasing the automation ratio of the production line. In addition, according to the present invention, the electrode leads 20 can be welded in a state in which mechanical pressure is applied, so that even when two or more electrode leads 20 are joined in parallel, reliability in electrical connectivity and mechanical bonding strength is improved. Can be maintained.
[41]
Hereinafter, the bus bar assembly 1 according to the present invention will be described in more detail.
[42]
First, since the insertion-type bus bar 100 is made of a material such as copper, silver, and tin-plated copper having electrical conductivity in a rod shape, a high-capacity current can be safely conducted. The anode leads 21 and the cathode leads 22 are in close contact with and welded to the insertion type busbar 100 so that they may be energized with each other. For example, in a configuration in which a total of six battery cells 10 are connected in parallel by three, as shown in FIGS. 2 to 3, the positive leads 21 of the three battery cells 10 are overlapped and the other three battery cells After the cathode lead 22 of (10) is overlapped and inserted into the fitting space (S), the ends thereof are closely adhered to and welded to both sides of the insertion-type busbar 100 to conduct electricity.
[43]
The insertion type bus bar 100 is provided to be movable in the Z-axis (±) direction with respect to the side contact type bus bar 200 and is supported by a support and holding member 300. For example, the inserted bus bar 100 is supported at a position protruding more than the side-adhered bus bar 200, and when an external force is applied in the Z axis (-) direction, the supporting bus bar 100 is supported and As the holding member 300 is elastically deformed, it may be moved in position on the same plane as the side contact type bus bar 200.
[44]
In addition, referring to FIGS. 5 and 7, the insertion type bus bar 100 may include a first flat portion 110a, a second flat portion 110b, and a tapered portion 120. The first flat portion 110a, the second flat portion 110b, and the tapered portion 120 may be continuously formed along the Z axis.
[45]
Each of the first flat portion 110a and the second flat portion 110b may have a uniform width, but the second flat portion 110b may have a smaller width than the first flat portion 110a. The first flat portion 110a may be specified as a portion that may be in surface contact with one end of the electrode lead 20, and the second flat portion 110b is specified as a portion pressed by the support and holding member 300 Can be. The tapered portion 120 may be specified as a portion whose width is gradually smaller in the Z-axis (-) direction.
[46]
Since the lower portion of the insertion type bus bar 100 is formed narrower than the upper portion based on the Z axis, when comparing the case where it protrudes more than the side contact type bus bar 200 and the case where it is not, the fitting space S is more It can be seen that it can be secured widely. Therefore, in this case, the electrode leads 20 can be easily interposed in the fitting space S, and when the electrode leads 20 are interposed, the insertion type bus bar 100 is pressed and lowered in the Z-axis (-) direction. The electrode leads 20 may be in close contact with the first flat portion 110a of the insertion type bus bar 100 and the side portion of the side contact type bus bar 200.
[47]
On the other hand, the side contact type bus bar 200 may be provided in, for example, a square frame shape having an empty space in the center, and a space to be inserted between the insertion type bus bar 100 with the insertion type bus bar 100 in the center (S) Can be formed. At this time, the fitting space (S) may be formed in two places on both sides of the insertion type bus bar (100).
[48]
In particular, in the case of the present embodiment, the side contact type bus bar 200 may be provided to be separated from each other by forming two pairs. The pair of side contact type busbars 200 may each include a contact portion 210 and a spacing adjustment portion 220 in a substantially "c" shape.
[49]
More specifically, the contact portion 210 may be defined as a portion arranged parallel to the insertion-type bus bar 100, and the spacing adjustment portion 220 is inserted into the bus bar 100 at both ends of the contact portion 210 ) May be defined as a portion extending to be bent toward. The pair of side-contact busbars 200 may be disposed symmetrically to each other with the insertion-type busbar 100 in the center to surround the outer periphery of the insertion-type busbar 100.
[50]
At this time, a fitting space (S) may be formed between both sides of the two contact portions 210 and the insertion type bus bar 100, and the spacing control unit 220 of any one side contact type bus bar 200 and The gap adjustment unit 220 of the other side-adhesive bus bar 200 may be configured to contact each other. In this case, energization may also be possible between the pair of side-closed bus bars 200.
[51]
In addition, since the pair of side contact type busbars 200 can be separated from each other, as shown in Figs. 4 and 5, the two side contact type busbars 200 are separated in the Y-axis (±) direction. I can put it. If the two side-contact type bus bars 200 are spaced apart from each other in this way, the fitting space S may be expanded more widely. The two side-adhesive busbars 200 spaced apart from each other are interposed between the electrode leads 20 in the fitting space S, and then to the elastic pressing portions 430 of the busbar support frame 400 to be described later. It can be pressed back into contact with each other.
[52]
On the other hand, unlike the present embodiment, since the side-contact type bus bar 200 forms a fitting space S and presses the electrode lead 20, it may not necessarily be made of a material having electrical conductivity. That is, since electricity between the anode leads 21 and the cathode leads 22 can be conducted only by the insertion type bus bar 100, the side contact type bus bar 200 may be formed of an insulating material different from the insertion type bus bar 100. . As an alternative to the present embodiment, if the side-closed bus bar 200 is made of an insulating material, it is considered that a better effect may be obtained in terms of preventing electric short circuit in the battery module.
[53]
The supporting and holding member 300 may be implemented as a structure having similar physical properties to the leaf spring 300 to the leaf spring 300. The leaf spring 300 according to the present embodiment has both ends for supporting the insert-type bus bar 100, and may be elastically opened to the left and right.
[54]
More specifically, when the tapered portion 120 of the insertion-type bus bar 100 is supported on both ends of the leaf spring 300, the insertion-type bus bar 100 descends in the Z-axis (-) direction by an external force. As both ends of the leaf spring 300 are further widened to the left and right, the insertion-type bus bar 100 is drawn into the inside of the leaf spring 300. The insertion type bus bar 100 may descend in the Z-axis (-) direction to a position where the first flat portion 110a of the insertion type bus bar 100 and the side portion of the side contact type bus bar 200 face each other.
[55]
As described above, when the inserted bus bar 100 is located on the same plane as the side-adhered bus bar 200, the leaf spring 300 has both ends at the second flat portion 110b of the inserted bus bar 100. The insertion type bus bar 100 is fixed by fitting and pressing the second flat portions 110b on both sides of the insertion type bus bar 100. At this time, after the external force disappears, the elastic restoring force of the leaf spring 300 acts as a force pressing both side portions of the insertion-type bus bar 100. For example, the welding jig may be inserted into the inside of the leaf spring 300 by pressing the insertion-type busbar 100 in the Z-axis (-) direction and descending, and then electrode after welding the electrode lead 20 The flow of the insertion-type bus bar 100 may be prevented by the bonding force with the lid 20 and the pressing force of the side contact type bus bar 200 and the pressure of the leaf spring 300 as described above.
[56]
Meanwhile, the busbar support frame 400 may be attached to the front/rear surfaces of the battery cell 10 stack. For example, the stack of battery cells 10 may be accommodated in a module housing (not shown). The module housing may be provided in the form of a tube with the front/rear sides open, and the busbar support frame 400 is coupled to the front/rear surfaces of the module housing and is located on the front/rear surfaces of the stack of battery cells 10 can do.
[57]
The bus bar support frame 400 is a plate-shaped structure, and the electrode lead 20 passes through a position corresponding to the fitting space S between the insertion type bus bar 100 and the pair of side contact type bus bars 200. Equipped with a slit 410, the insertable bus bar 100 is movable in the Z-axis (±) direction, and the side-closed busbar 200 is inserted in the Y-axis (±) direction. It can be configured to be close to the direction.
[58]
To this end, the bus bar support frame 400 may further include a clamping portion 420, an elastic pressing portion 430, and a corner bracket portion 440.
[59]
The clamping part 420 is provided in a position opposite to the leaf spring 300 with the insertion-type bus bar 100 interposed therebetween, and serves to restrain the insertion-type bus bar 100 so as to be protruded by the leaf spring 300. The upper end of the inserted bus bar 100 in the supported state is supported in the Z-axis (-) direction.
[60]
In this embodiment, the clamping part 420 takes a shape bent at a substantially right angle with respect to the plate surface of the bus bar support frame 400, and supports both ends of the insertion-type bus bar 100 based on the X-axis direction. Is configured to Therefore, the insertion-type bus bar 100 may be constrained in a state partially inserted into the leaf spring 300 by the clamping portion 420, and may be drawn deeper into the inside of the leaf spring 300 when an external force acts. .
[61]
The elastic pressing unit 430 is configured to elastically press both sides of the side-contact type bus bar 200. As described above, the side contact type bus bar 200 may be configured to be separated from each other by making two pairs, and to secure a fitting space (S), they may be separated from each other. The elastic pressing unit 430 serves to pressurize the pair of side-contact busbars 200 in a spaced and separated state in the lateral direction, that is, in the Y-axis (±) direction, to bring them into close contact again.
[62]
More specifically, in the present embodiment, the elastic pressing unit 430 may be implemented in the form of a plate having a cantilever structure in which one surface contacts the outer surface of the pair of side-contact bus bars 200. For example, as shown in FIGS. 5 and 7, when the right side contact type bus bar 200 is pulled in the Y-axis (-) direction, the elastic pressing unit 430 is bent within the elastic range and then the right side contact type When the bus bar 200 is released, it recovers to its original state and pushes the right side contact type bus bar 200 in the Y-axis (+) direction.
[63]
The corner bracket portion 440 serves to support the pair of side contact type bus bars 200 while allowing the flow of the pair of side contact type bus bars 200.
[64]
In this embodiment, there are a total of four corner bracket portions 440, and the four corner bracket portions 440 are located at the corners of the side-contact type bus bar 200 to flow the side-contact type bus bar 200. Constrain as possible. Specifically, the corner bracket portion 440 may be configured to surround four corner portions in a state in which the pair of side-contact busbars 200 are spaced farthest to each side. In other words, the four corner brackets 440 restrain a pair of side-adhesive bus bars 200 up, down, left, and right, and have a flow allowable space as indicated by D in FIG. 7, for example. It is possible to move the side contact type bus bar 200 within the flow allowable space of 440.
[65]
8 and 9 are diagrams schematically showing a configuration before and after bonding of an electrode lead and a busbar assembly according to an embodiment of the present invention.
[66]
Next, the operation of the busbar assembly 1 and the bonding method of the electrode lead 20 according to the present invention will be briefly described with reference to FIGS. 8 to 9. This embodiment is an example in which three battery cells 10 are connected in parallel and the positive lead 21 and the negative lead 22 are bonded to the busbar assembly 1.
[67]
First, as shown in FIG. 8, a sufficient space (S) of the bus bar assembly 1 is secured. At this time, as described above, the insertion type bus bar 100 may be positioned to protrude from the side contact type bus bar 200, and the side contact type bus bars 200 may be spaced apart to sufficiently secure the fitting space S.
[68]
Then, the ends of the anode leads 21 and the ends of the cathode leads 22 are inserted into the fitting space S, respectively. The fitting space (S) is two sides on both sides of the inserted bus bar (100). The anode leads 21 and the cathode leads 22 are inserted into the fitting space (S) and disposed only at their ends as a bundle.
[69]
Next, as shown in FIG. 9, the insertion type bus bar 100 is lowered to the same plane as the side contact type bus bar 200 and the side contact type bus bar 200 is brought into close contact with the anode lead 21 and the cathode lead ( 22) to be pressed between the insertion type bus bar 100 and the side contact type bus bar 200. In this state, welding is performed on the positive electrode leads 21 and the negative electrode leads 22.
[70]
According to the structure and operation of the busbar assembly 1 according to the present invention, a bending process of the electrode lead 20 as in the prior art (see FIG. 1) is not required at all in the welding process of the electrode lead 20. Accordingly, a manual process for bending the electrode leads 20 may be eliminated, thereby improving the automation rate of the battery module production line.
[71]
In addition, since the integral electrode leads 20 can be welded in a mechanically pressed state, electrical connectivity and reliability of mechanical bonding strength can be improved regardless of the number of electrode leads 20 in a parallel connection structure.
[72]
On the other hand, the battery module according to the present invention may be configured to include the above-described bus bar assembly. In addition, the battery module includes a battery cell stack, a module housing for accommodating the battery cell stack, various devices (not shown) for controlling charging and discharging of the battery cells, such as BMS (Battery Management System), a current sensor, a fuse, etc. It may further include. Such a battery module may be used as an energy source for an electric vehicle, a hybrid vehicle, or a power storage device.
[73]
As described above, although the present invention has been described by a limited number of embodiments and drawings, the present invention is not limited thereto, and the technical idea of ​​the present invention and the following will be described by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the equivalent scope of the claims to be described.
[74]
On the other hand, in the present specification, terms indicating directions such as up, down, left, and right are used, but these terms are for convenience of explanation only, and may vary depending on the position of an object or the position of an observer. It is apparent to those skilled in the art.

Claim
[Claim 1]
A bus bar assembly for electrically connecting a plurality of battery cells with electrode leads, comprising: an inserted bus bar provided in the form of a rod conductor; A side-contact type bus bar having the insertion type busbar in the center and forming a fitting space in which at least one electrode lead can be interposed on both sides of the insertion type busbar; And supporting the insertion-type busbar in a more protruding position than the side-contact busbar, but when the insertion-type busbar is pressed, it is provided to be elastically deformable by the insertion-type busbar so that it is located on the same plane as the side-contact busbar. Busbar assembly, characterized in that it comprises a supporting and holding member.
[Claim 2]
The method of claim 1, wherein the support and holding member has both ends for supporting the insertion type bus bar, and is provided to be elastically spread to the left and right, and when the insertion type bus bar is inserted into the inner side, the insertion type bus bar is A bus bar assembly, characterized in that it is a leaf spring pressing both sides.
[Claim 3]
The bus bar assembly according to claim 2, wherein the inserted bus bar has a tapered portion whose width is gradually reduced to be introduced into a space between both ends of the leaf spring.
[Claim 4]
The method of claim 2, wherein the insertion type busbar comprises a first flat portion facing a side surface of the side contact busbar on the same plane as the side contact busbar, and a width smaller than the first flat portion, and the A bus bar assembly comprising: a second flat portion pressed by both ends of the leaf spring.
[Claim 5]
According to claim 1, The side-adhesive bus bar is provided to be mutually separable by pairing the two, each of which is provided in close contact with the insertion-type bus bar, and bent at both ends of the contact portion. A bus bar assembly comprising an extended spacing adjustment portion, and being disposed to be symmetrical to each other with the insertion-type busbar in the center to surround the circumference of the insertion-type busbar.
[Claim 6]
The plate-shaped structure of claim 1, further comprising a bus bar support frame having a slit through which the electrode lead can pass at a position corresponding to the fitting space, and supporting the insertion type bus bar and the side contact type bus bar. Bus bar assembly, characterized in that.
[Claim 7]
The bus bar assembly of claim 6, wherein the bus bar support frame further comprises a clamping portion provided at a position facing the support and holding member with the insert bus bar interposed therebetween to restrain the insert bus bar.
[Claim 8]
The bus bar assembly of claim 6, wherein the bus bar support frame further includes elastic pressing portions provided to elastically press both sides of the side-contact type bus bar.
[Claim 9]
The bus bar assembly of claim 6, wherein the bus bar support frame further comprises a corner bracket portion provided to surround and support four corner portions of the side-contact type bus bar.
[Claim 10]
A battery module comprising the bus bar assembly according to any one of claims 1 to 9.