Title of the invention: Battery module having foldable side plate and manufacturing method thereof
Technical field
[One]
The present invention relates to a battery module including a foldable side plate, and a battery pack and a vehicle including the same. In the present invention, more specifically, a pair of foldable side plates that connect a pair of unit modules are used to pressurize a pair of unit modules at the same time, and after welding between the electrode lead and the bus bar, pressurization It relates to a battery module having a structure capable of allowing a pair of unit modules to be arranged side by side along the length direction of the foldable side plate while maintaining, and a battery pack and a vehicle including the same.
[2]
This application is a priority claim application for Korean Patent Application No. 10-2019-0002468 filed on January 8, 2019, and all contents disclosed in the specification and drawings of the application are incorporated herein by reference.
Background
[3]
Conventionally, in the case of manufacturing a long module by arranging a pair of unit modules in which a cell stack and a bus bar frame are combined side by side along the length direction, the electrode lead/bus bar Surface pressing on the cell stack for performing the welding process was individually performed.
[4]
That is, after performing the welding process for bonding between the electrode lead and the busbar while maintaining the surface pressurization of the cell stack for one unit module, the same process is performed for the other unit module. After completing the unit modules of, the two unit modules were arranged side by side along the length direction, and the housing was assembled/welded.
[5]
However, in the case of following such a conventional process, the surface pressurization and the release of the surface pressurization are inevitably repeated for each unit module, and this causes a relative movement between the electrode lead and the busbar, thereby causing the electrode lead and the electrode. This results in an accumulation of stress in the welding area between the lead and the busbar.
[6]
In addition, the accumulation of these stresses may lead to product defects due to damage to parts or welding parts during the production process or the use process of the product.
[7]
Therefore, when manufacturing a long module type battery module having a structure in which a pair of unit modules are arranged side by side along the length direction, the surface pressurization and release of the surface pressurization on the unit module are not repeated, and the surface pressurization state is maintained continuously. It is necessary to be able to achieve this, and development of a battery module having a structure that enables the maintenance of such a surface pressurization state is required.
Detailed description of the invention
Technical challenge
[8]
The present invention, as invented in consideration of the above-described problems, is a combination of surface pressurization and surface pressurization of a unit module in manufacturing a long module type battery module having a structure in which a pair of unit modules are arranged side by side along the length direction. One object is to ensure that the release is not repeated and the surface pressurization state can be maintained continuously.
[9]
However, the technical problem to be solved by the present invention is not limited to the above-described problem, 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.
Means of solving the task
[10]
A battery module according to an embodiment of the present invention for solving the above-described problems includes a cell stack including a plurality of battery cells stacked up and down, and a bus bar frame assembly covering the front and rear surfaces of the cell stack. A first module and a second module including; And a first side plate that covers and presses one side and the other side of the first module, and a second side plate that covers and presses the side and the other side of the second module and is hinged with the first side plate. A pair of foldable side plates including; Includes.
[11]
The foldable side plate may be folded so that the first side plate and the second side plate are disposed parallel to each other in the width direction by performing a relative rotational movement around the hinge coupling portion, or may be unfolded so as to be disposed parallel to each other in the length direction.
[12]
The first module and the second module may be disposed side by side along a width direction as the foldable side plate is folded, and may be disposed side by side along a length direction as the foldable side plate is unfolded.
[13]
The bus bar frame assembly may include: a front bus bar frame covering a front surface of the cell stack; And a rear bus bar frame covering a rear surface of the cell stack. It may include.
[14]
The first side plate and the second side plate may extend in a direction from the rear bus bar frame toward the front bus bar frame, and may have a length extending beyond the front bus bar frame.
[15]
The front busbar frame may include a pair of module terminals electrically connected to the cell stack.
[16]
When the pair of foldable side plates are unfolded, a pair of module terminals provided in the first module and a pair of module terminals provided in the second module may face each other.
[17]
The battery module covers the upper and lower surfaces of the first module and the second module, respectively, when a pair of the foldable side plates are unfolded while maintaining pressure on the first module and the second It may further include an upper housing and a lower housing coupled to the foldable side plate.
[18]
The battery module may further include a pair of end plates coupled to rear surfaces of the first module and the second module.
[19]
[20]
In addition, a battery module and a vehicle according to an embodiment of the present invention for solving the above-described problems include a battery module according to an embodiment of the present invention as described above.
[21]
[22]
On the other hand, in the manufacturing method of a battery module according to an embodiment of the present invention for solving the above-described problem, a cell stacking method in which a pair of battery cell stacks are provided and arranged side by side with each other along the width direction of the battery cell stacked body. Sieve placement step; A pressing start step of pressing both sides of the pair of battery cell stacks in the width direction using a pair of folded side plates in a folded state; The first module and the second module including the cell stack and the bus bar frame assembly are formed by combining the bus bar frame assembly so that the front and rear surfaces of each of the cell stacks are covered while maintaining the pressure on the cell stack. Module formation step; An unfolding step of spreading the foldable side plate while maintaining pressure on the cell stack so that the first module and the second module are arranged side by side along a length direction; A housing coupling step of coupling an upper housing and a lower housing covering the upper and lower surfaces of the first module and the second module by welding with the foldable side plate while maintaining pressure on the cell stack; And an end plate coupling step of coupling a pair of end plates covering the rear surfaces of the first module and the second module.
Effects of the Invention
[23]
According to an aspect of the present invention, when manufacturing a long module type battery module having a structure in which a pair of unit modules are arranged side by side along the length direction, the surface pressing and the release of the surface pressing on the unit module are not repeated and are continuous. As a result, it is possible to prevent stress from accumulating in the electrode lead and the welding portion between the electrode lead and the bus bar.
Brief description of the drawing
[24]
The following drawings attached to the present specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of ​​the present invention together with the detailed description of the present invention to be described later. It is limited to and should not be interpreted.
[25]
1 is an exploded perspective view showing a battery module according to an embodiment of the present invention.
[26]
2 is a perspective view showing a cell laminate.
[27]
3 is an exploded perspective view showing a cell stack and a foldable side plate.
[28]
4 is an exploded perspective view and a partial enlarged view showing a foldable side plate.
[29]
5 is a view showing a folded side plate.
[30]
6 is a view showing a state in which the foldable side plate is unfolded.
[31]
7 to 9 are surface pressurization of the cell stack from the process of assembling the busbar frame assembly to the cell stack to the step of unfolding the folded side plates so that a pair of unit modules are arranged side by side along the length direction. It is a figure which shows how it is maintained.
[32]
10 is a complete perspective view of a battery module according to an embodiment of the present invention.
Mode for carrying out the invention
[33]
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 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. Accordingly, the embodiments described in the present specification and the configurations shown in the drawings are only some of the most preferred embodiments of the present invention, and do not represent all the technical spirit of the present invention. It should be understood that there may be equivalents and variations.
[34]
[35]
First, referring to FIG. 1, a battery module according to an embodiment of the present invention includes a cell stack 100, a pair of foldable side plates 200, and a pair of busbar frame assemblies. 300, the upper housing 400, the lower housing 500, and may be implemented in a form including an end plate 600.
[36]
Referring to FIG. 2, the cell stack 100 includes a plurality of battery cells 110 stacked along an up-down direction (a direction parallel to the X-axis of FIG. 2) and between and/or adjacent battery cells 110. It includes a plurality of buffer pads 120 disposed on the outer surface of the battery cell 110 disposed on the outermost side.
[37]
As the battery cell 110, for example, a pouch type battery cell may be applied. When a pouch-type battery cell is used as the battery cell 110, electrode leads 111 are provided on one side and the other side in the length direction of the battery cell 110, respectively. The electrode lead 111 is a thin metal plate and is connected to an electrode tab formed in an electrode assembly (not shown) disposed inside the battery cell 110, that is, inside the pouch case, and is drawn out of the pouch case.
[38]
When the buffer pad 120 is interposed between the outside and/or adjacent battery cells 110 of the cell stack 100 and presses both sides of the cell stack 100, the cell stack 100 is Allow it to contract. In order to allow the cell stack 100 to be contracted as described above, the buffer pad 120 is preferably made of a material having elasticity, such as a sponge.
[39]
The cell stack 100 is coupled to the busbar frame assembly 300 in a state where both sides are pressed by the foldable side plate 200, and the foldable side plate 200 is in a state in which the pressing force is maintained. The coupling between the and the housings 400 and 500 is achieved by welding. That is, in the completed battery module, the buffer pad 120 is in a contracted state, and accordingly, due to the stored elastic energy, it is possible to suppress the occurrence of swelling caused by repeated use of the battery module.
[40]
As shown in FIG. 2, the cell stack 100 includes a first cell stack 100A arranged side by side along the width direction of the cell stack 100 (a direction parallel to the Z axis in FIG. 2 ), and It includes a second cell stack 100B. In this way, the first cell stack 100A and the second cell stack 100B are arranged parallel to each other in the width direction when the foldable side plate 200 to be described later is in a folded state, and the folder In the unfolded state of the black side plate 200, the first cell stack 100A and the second cell stack 100B are disposed in parallel with each other along the longitudinal direction (a direction parallel to the Y-axis in FIG. 2).
[41]
3, a pair of the foldable side plates 200 are provided, and each of the foldable side plates 200 are first arranged side by side along a width direction (a direction parallel to the Z axis in FIG. 3). It is attached to one side and the other side of the cell stack 100A and the second cell stack 100B, and pressurizes the cell stack 100 to contract.
[42]
The foldable side plate 200 is a component disposed to cover one side and the other side of the cell stack 100 by combining the upper housing 400 and the lower housing 500 to be described later, and at the same time It is a means for pressing the laminate 100.
[43]
4 to 6, the foldable side plate 200 includes a first side plate 210 and a second side plate 220 that are hinged to each other to enable relative rotation. By such a hinged coupling, the pair of side plates 210 and 220 may be folded as shown in FIG. 5 and disposed side by side along the width direction (a direction parallel to the Z axis in FIG. 5), as shown in As shown, they may be unfolded and arranged side by side along the longitudinal direction (a direction parallel to the Y-axis in FIG. 6) with each other.
[44]
Referring to FIG. 4, the hinge coupling between the first side plate 210 and the second side plate 220 is, for example, a corner area at one end of the first side plate 210 in the length direction. It may be made by fastening between the coupling hole H formed in the second side plate 220 and the coupling protrusion P formed in a corner region of one end of the second side plate 220 in the length direction. In addition, the coupling hole H may be formed in the second side plate 220 and the coupling protrusion P may be formed in the first side plate 210.
[45]
Referring to FIGS. 5 and 6 along with FIG. 3, the first side plate 210 covers one side and the other side (a surface parallel to the YZ plane of FIG. 3) of the first cell stack 100A. . Similarly, the second side plate 220 covers one side and the other side (a surface parallel to the YZ plane of FIG. 3) of the second cell stack 100B.
[46]
7 and 8, the bus bar frame assembly 300 is provided with a pair, and each bus bar frame assembly 300 is a front bus bar frame 310, a rear bus bar frame 320 and Includes a cover plate (330). The front busbar frame 310, the rear busbar frame 320, and the cover plate 330 are made of a material having electrical insulating properties such as resin.
[47]
Each of the pair of busbar frame assemblies 300 is stacked with a first cell stack 100A and a second cell stacked in a state in which the cell stack 100 is pressed by the foldable side plate 200 in the direction of the arrow. It is coupled to cover the front and rear surfaces of the sieve 100B (a surface parallel to the XZ plane of FIGS. 7 and 8 ), and an upper surface (a surface parallel to the XY plane of FIGS. 7 and 8 ).
[48]
The pair of front busbar frames 310 are coupled to cover the front surfaces of the first cell stack 100A and the second cell stack 100B, respectively, and the pair of rear busbar frames 320 are each The first cell stack 100A and the second cell stack 100B are coupled to cover the rear surfaces. In addition, the pair of cover plates 330 are coupled to cover upper surfaces of the first cell stack 100A and the second cell stack 100B, respectively. The cover plate 330 may be hinge-coupled with the front bus bar frame 310 and the rear bus bar frame 320, respectively, at both ends of the cover plate 330 in the longitudinal direction, thereby The frame 320 can rotate relative to the cover plate 330.
[49]
Due to the hinged structure between the bus bar frames 310 and 320 and the cover plate 330, the cover plate 330 is seated at a predetermined position on the upper surface of the cell stacks 100A and 100B, and then the bus bar frame ( By rotating the 310 and 320, the front and rear surfaces of the cell stacks 100A and 100B can be accurately covered.
[50]
On the bus bar frames 310 and 320, a plurality of bus bars (B) are provided along the length direction (a direction parallel to the X-axis in FIGS. 7 and 8), and the bus bar (B) includes a bus bar frame ( The electrode leads 111, which are drawn out through the slits formed in the 310 and 320, are coupled to the outside by welding. Electrode leads 111 of two or more battery cells 110 to be electrically connected to each other may be coupled to one bus bar B.
[51]
In addition, a pair of module terminals T is provided on the front busbar frame 310, and the pair of module terminals T is in the width direction of the cell stacks 100A and 100B (Figs. 7 and 8). It is coupled to the electrode lead 111 of the battery cell 110 located on the outermost side along the direction parallel to the X axis of. In the present invention, the distinction between the front bus bar frame 310 and the rear bus bar frame 320 is determined according to whether or not a module terminal T is provided. That is, in the present invention, the bus bar frame on which the module terminal (T) is formed is defined as the front bus bar frame 310, and the bus bar frame on which the module terminal (T) is not formed is the rear bus bar frame (320). ).
[52]
On the other hand, welding between the electrode lead 111 and the bus bar (B) and welding between the electrode lead 111 and the module terminal (T) is performed in a state in which pressurization by the foldable side plate 200 is maintained, In addition, the foldable side plate 200 is folded so that a pair of cell stacks 100A and 100B are arranged adjacent to each other in parallel along the width direction thereof.
[53]
The first module M1 including the first cell stack 100A, the first side plate 210, and the bus bar frame assembly 300 according to the combination of the pair of busbar frame assemblies 300 The second module M2 including the two-cell stack 100B, the second side plate 220 and the busbar frame assembly 300 is
[54]
8 and 9, the first side plate 210 and the second side plate 220 constituting the foldable side plate 200 are separated from the rear bus bar frame 320 to the front bus bar frame 310. Doedoe extending in a direction toward ), it has a length that extends beyond the front bus bar frame 320. In addition, the first side plate 210 and the second side plate 220 are hinged to each other at a position corresponding to the front bus bar frame 310 of both ends in the length direction.
[55]
Accordingly, when the foldable side plate 200 is unfolded, the first module M1 and the second module M2 are in a state in which the front busbar frames 310 face each other in the longitudinal direction (FIG. 9). A pair of module terminals (T) provided in the first module (M1) and a pair of module terminals provided in the second module (M2) are arranged adjacent to each other along the Y-axis of the (T) face each other.
[56]
Meanwhile, even in the process of unfolding the foldable side plate 200 so that the modules M1 and M2 are arranged adjacent to each other along the length direction, the foldable side plate 200 presses the cell stack 100. Is maintained.
[57]
[58]
Referring to FIG. 10, in the upper housing 400 and the lower housing 500, a pair of foldable side plates 200 are unfolded while maintaining pressure on the first module M1 and the second module M2. In this state, the upper and lower surfaces of the first module M1 and the second module M2 (surfaces parallel to the XY plane of FIG. 10) are respectively covered.
[59]
Both corners of the upper housing 400 and the lower housing 500 in the width direction (parallel to the X-axis in FIG. 10) are in the width direction of the foldable side plate 200 (surface parallel to the YZ plane in FIG. 10). The side edges are joined by welding. The coupling between the housings 400 and 500 and the foldable side plate 200 by welding is performed in a state in which the pressure of the cell stack 100 by the foldable side plate 200 is maintained.
[60]
As shown in Fig. 10, the end plate 600 is provided with a pair, and each end plate 600 is a front and rear side of the battery module according to an embodiment of the present invention (parallel to the XZ plane of Fig. 10). Cotton). That is, the pair of end plates 600 are coupled to the rear surfaces of the first module M1 and the second module M2, respectively.
[61]
As described above, the battery module according to an embodiment of the present invention performs a subsequent process while continuously maintaining a state in which the pair of modules M1 and M2 is pressed using the foldable side plate 200. It has a structure that can be used.
[62]
Specifically, the battery module, by applying the foldable side plate 200, as shown in FIG. A welding process between the electrode lead 111 and the bus bar B may be smoothly performed. In the case of the battery module to which the foldable side plate 200 is not applied, similarly to that shown in FIG. 9, a pair of modules are arranged adjacent to each other along the length direction, and then both sides of the pair of modules are pressed with the side plate. In this state, it is necessary to perform welding between the electrode lead and the bus bar. In this case, the space between the module and the module is very narrow, so that the welding cannot be performed smoothly at the front of the module. In addition, after the welding process is individually performed for each of the pair of modules, when the pair of modules is arranged side by side along the length direction and a side plate is attached, continuous pressure on the module cannot be performed.
[63]
According to the structure of the battery module according to an embodiment of the present invention, the pressurization of the modules M1 and M2 by the foldable side plate 200 is maintained while the foldable side plate 200 is folded. By performing welding and combining the housings 400 and 500 while the foldable side plate 200 is unfolded, both the ease of welding and the continuous maintenance of pressure in the process are possible.
[64]
[65]
A method for manufacturing a battery module according to an embodiment of the present invention for manufacturing a battery module according to an embodiment of the present invention includes: (S1) arranging a cell stack; (S2) pressurization start step; (S3) module formation step; (S4) unfolding step; (S5) housing coupling step; And (S6) coupling the end plate.
[66]
The cell stack arrangement step (S1) is a step of preparing a pair of battery cell stacks 100A and 100B and arranging them side by side along the width direction of the battery cell stacks 100A and 100B. The pressing start step (S2) is a step of pressing both sides of the pair of battery cell stacks 100A and 100B in the width direction using a pair of the foldable side plates 200 in a folded state.
[67]
The module forming step (S3) is a bus bar so that the front and rear surfaces of each of the cell stacks 100A and 100B are covered while maintaining the pressurization of the cell stacks 100A and 100B started in the pressurization start step S2. This is a step of combining the frame assembly 300 to form a first module M1 and a second module M2 including the cell stack 100 and the busbar frame assembly 300. In the unfolding step (S4), the foldable side plate 200 is unfolded while maintaining the pressure on the cell stack 100 made in the module forming step S3, and the first module M1 and the second module M2 are ) Are arranged side by side along the length direction.
[68]
The housing coupling step (S5) includes an upper portion covering the upper and lower surfaces of the first module M1 and the second module M2 while maintaining pressure on the cell stack 100 made in the unfolding step (S4). In this step, the housing 400 and the lower housing 500 are coupled to the foldable side plate 200 by welding. The end plate coupling step (S6) is a step of coupling a pair of end plates 600 covering the rear surfaces of the first module M1 and the second module M2. The steps S1 to S6 are performed sequentially.
[69]
[70]
In the above, although the present invention has been described by the limited 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 of ordinary skill in the art to which the present invention pertains. It goes without saying that various modifications and variations are possible within the equivalent range of the claims.
Claims
[Claim 1]
A first module and a second module including a cell stack including a plurality of battery cells stacked vertically and a bus bar frame assembly covering front and rear surfaces of the cell stack; And a first side plate that covers and presses one side and the other side of the first module, and a second side plate that covers and presses the side and the other side of the second module and is hinged with the first side plate. A pair of foldable side plates including; Battery module comprising a.
[Claim 2]
The method of claim 1, wherein the foldable side plate is folded so that the first side plate and the second side plate are arranged side by side along the width direction by performing a relative rotational movement around the hinge coupling portion, or Battery module, characterized in that unfolded so as to be disposed.
[Claim 3]
The method of claim 2, wherein the first module and the second module are arranged side by side along the width direction of each other as the foldable side plate is folded, and are arranged side by side along the length direction of each other as the foldable side plate is unfolded. Battery module, characterized in that the.
[Claim 4]
The apparatus of claim 1, wherein the bus bar frame assembly comprises: a front bus bar frame covering a front surface of the cell stack; And a rear bus bar frame covering a rear surface of the cell stack. Battery module comprising a.
[Claim 5]
The method of claim 4, wherein the first side plate and the second side plate extend in a direction from the rear bus bar frame toward the front bus bar frame, and have a length extending beyond the front bus bar frame. Battery module.
[Claim 6]
The battery module of claim 4, wherein the front busbar frame includes a pair of module terminals electrically connected to the cell stack.
[Claim 7]
The method of claim 6, wherein when the pair of foldable side plates are unfolded, a pair of module terminals provided in the first module and a pair of module terminals provided in the second module face each other. Battery module.
[Claim 8]
The method of claim 7, wherein the battery module comprises upper and lower surfaces of the first module and the second module in an unfolded state while the pair of the foldable side plates are pressed against the first module and the second module. The battery module, further comprising an upper housing and a lower housing respectively covering and coupled to the pair of foldable side plates.
[Claim 9]
The battery module of claim 8, wherein the battery module further comprises a pair of end plates coupled to rear surfaces of the first module and the second module.
[Claim 10]
A battery pack comprising the battery module according to any one of claims 1 to 9.
[Claim 11]
A vehicle comprising the battery module according to any one of claims 1 to 9.
[Claim 12]
A cell stack arrangement step of preparing a pair of battery cell stacks and arranging them side by side along the width direction of the battery cell stack; A pressing start step of pressing both sides of the pair of battery cell stacks in the width direction using a pair of folded side plates in a folded state; The first module and the second module including the cell stack and the bus bar frame assembly are formed by combining the bus bar frame assembly so that the front and rear surfaces of each of the cell stacks are covered while maintaining the pressure on the cell stack. Module formation step; An unfolding step of spreading the foldable side plate while maintaining pressure on the cell stack so that the first module and the second module are arranged side by side along a length direction; A housing coupling step of coupling an upper housing and a lower housing covering the upper and lower surfaces of the first module and the second module by welding with the foldable side plate while maintaining pressure on the cell stack; And an end plate coupling step of coupling a pair of end plates covering rear surfaces of the first module and the second module. Method of manufacturing a battery module comprising a.