Battery module

Abstract

A battery module according to an embodiment of the present invention may include a module frame, a plurality of battery cells housed in the module frame and each having an electrode lead, a bus bar frame having a bus bar disposed on one side of the plurality of battery cells and connected to the electrode lead, and a stopper disposed between the plurality of battery cells and the bus bar frame and configured to absorb impacts applied to the battery cells. The stopper may include an exterior material having an elastic material or a sponge material, and an impact absorbing member disposed inside the exterior material.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0000189, dated January 2, 2023, and all contents disclosed in the documents of this Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module including a plurality of battery cells. [Background technology]

[0003] Lithium secondary batteries are generally manufactured by coating a positive electrode active material slurry on a positive electrode current collector and a negative electrode current collector to form a positive electrode and a negative electrode, stacking these on both sides of a separator to form an electrode assembly of a predetermined shape, and then placing the electrode assembly in a pouch and injecting an electrolyte solution.

[0004] Secondary batteries are classified into pouch types and can types depending on the material of the case that houses the electrode assembly. Pouch-type secondary batteries are manufactured by pressing a flexible pouch film laminate to form a cup, placing an electrode assembly in the cup, injecting an electrolyte, and then sealing the sealing part. Can-type secondary batteries are manufactured by placing an electrode assembly in a metal can, injecting an electrolyte, and then assembling a top cap on the top of the can to seal it.

[0005] Pouch-type secondary batteries have advantages such as light weight, excellent space utilization, and the ability to achieve high energy density using a stacked electrode assembly, but have a drawback in that they are more vulnerable to external impacts than can-type secondary batteries. Recently, as secondary batteries are used in a variety of environments, there is a demand for them to have excellent safety even in harsh environments, and therefore there is a need to improve the impact resistance of pouch-type secondary batteries.

[0006] In particular, pouch-type secondary batteries are generally stacked together to form a battery module rather than being used individually, and therefore a structure for improving the impact resistance of pouch-type secondary batteries at the battery module level is required. Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a battery module that is capable of suppressing detachment of an electrode assembly from a battery cell and / or leakage of electrolyte when subjected to an external impact. [Means for solving the problem]

[0008] A battery module according to an embodiment of the present invention may include a module frame, a plurality of battery cells housed in the module frame and each having an electrode lead, a bus bar frame having a bus bar disposed on one side of the plurality of battery cells and connected to the electrode lead, and a stopper disposed between the plurality of battery cells and the bus bar frame and configured to absorb impacts applied to the battery cells. The stopper may include an exterior material having an elastic material or a sponge material, and an impact absorbing member disposed inside the exterior material.

[0009] The stopper may be elastically deformed when struck by the battery cell.

[0010] The stoppers may be provided in a plurality so as to be arranged at regular intervals in the stacking direction of the plurality of battery cells, and a portion of each stopper may face one battery cell and another portion may face another battery cell adjacent to the one battery cell.

[0011] The stopper may extend in a width direction of the battery cell.

[0012] The stopper may be formed in a convex shape toward the plurality of battery cells.

[0013] The stopper may be coupled to the bus bar frame.

[0014] The stoppers may be provided in a plurality at regular intervals in a stacking direction of the plurality of battery cells, and the bus bar frame may be formed with a plurality of slits that are open toward spaces between the plurality of stoppers and through which the electrode leads pass.

[0015] The length of the stopper may be longer than the length of the slit.

[0016] The length of the stopper may correspond to the overall length of the battery cell.

[0017] The shock absorbing member may be a breaking member that is broken irreversibly by an impact.

[0018] The breaking member may have a zigzag shape so as to intersect a virtual line parallel to the overall length of the battery cell multiple times.

[0019] The shock absorbing member may be an elastic member that is compressed by a shock.

[0020] The elastic member may be a spring that is elastically deformed in a direction parallel to the overall length of the battery cell.

[0021] The shock absorbing members may be provided in a plurality at predetermined intervals along the length of the stopper. [Effects of the Invention]

[0022] According to a preferred embodiment of the present invention, the stopper can absorb impacts applied to the battery cell, thereby reducing the risk of the sealing portion of the battery cell being damaged or penetrated when an external impact occurs, and suppressing separation of the electrode assembly and / or leakage of electrolyte, thereby achieving excellent impact resistance.

[0023] In addition, the present invention can include other effects that can be easily predicted by a person skilled in the art from the configuration of the preferred embodiment of the present invention. [Brief explanation of the drawings]

[0024] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited solely to the matters depicted in such drawings. [Figure 1] 1 is a perspective view of a battery module according to an embodiment of the present invention; [Figure 2] 1 is an exploded perspective view of a battery module according to an embodiment of the present invention; [Figure 3] FIG. 2 is a front view of a battery cell according to an embodiment of the present invention. [Figure 4] 4 is an enlarged partial perspective view of a portion of the battery cell stack and bus bar frame shown in FIG. 3. FIG. [Figure 5] 5 is a perspective view of the bus bar frame shown in FIG. 4, viewed from another direction. [Figure 6] 1 is a cross-sectional view illustrating a stopper and its surrounding configuration according to an embodiment of the present invention; [Figure 7] 1 is a schematic diagram of a stopper according to one embodiment of the present invention. [Figure 8] 10 is a schematic diagram of a stopper according to another embodiment of the present invention. [Figure 9] 10 is a schematic view of a stopper according to yet another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily understand and practice the present invention. However, the present invention may be embodied in various different forms and should not be construed as being limited to the following embodiments.

[0026] In order to clearly explain the present invention, detailed descriptions of parts that are not relevant to the description or related known technologies that may obscure the gist of the present invention are omitted, and when referring to components in each drawing in this specification, the same or similar reference symbols are used throughout the specification to refer to the same or similar components.

[0027] Furthermore, the terms and words used in this specification and claims should not be interpreted in a limited way to their ordinary and dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of ​​the present invention, in accordance with the principle that an inventor can appropriately define the concept of a term in order to best explain his or her invention.

[0028] FIG. 1 is a perspective view of a battery module according to one embodiment of the present invention, and FIG. 2 is an exploded perspective view of the battery module according to one embodiment of the present invention.

[0029] The battery module 100 according to the first embodiment of the present invention may include a plurality of battery cells 110, a module frame 200, and a bus bar frame 300.

[0030] A plurality of battery cells 110 may be housed in the module frame 200. The plurality of battery cells 110 may be arranged parallel to one another. The plurality of battery cells 110 may be arranged to face one another in a first direction (e.g., a direction parallel to the Y-axis). More specifically, the plurality of battery cells 110 may be stacked on one another in the first direction. Furthermore, each battery cell 110 may be arranged elongated in a second direction (e.g., a direction parallel to the X-axis) perpendicular to the first direction. The first direction may be parallel to the overall width direction of the module frame 200 described below, and the second direction may be parallel to the overall length direction of the module frame 200.

[0031] Each battery cell 110 may be a pouch-type battery cell. Pouch-type battery cells can maximize the number of stacked layers per unit area, thereby increasing the energy density of the battery module 100. Pouch-type battery cells 110 may be manufactured by placing an electrode assembly including a positive electrode, a negative electrode, and a separator in a cell case formed from a laminate sheet, and then heat-sealing the cell case. However, the battery cells 110 do not necessarily have to be provided in a pouch type, and may be provided in a prismatic, cylindrical, or other various shapes as long as the storage capacity required by the device to be subsequently installed is achieved.

[0032] Each battery cell 110 may be provided with an electrode lead 111. The electrode leads 111 may be provided in pairs protruding in opposite directions, or may protrude parallel to the length of the battery cell 110. However, the present invention is not limited thereto, and the pair of electrode leads 111 may also protrude parallel to each other in the same direction.

[0033] A plurality of battery cells 110 stacked on one another may form a battery cell stack 120. The battery cell stack 120 may also include at least one heat dissipation pad 150 for dissipating heat from the battery cells 110. The heat dissipation pad 150 may be disposed between the plurality of battery cells 110 or may be disposed to cover the outermost battery cell 110.

[0034] The module frame 200 may form the exterior of the battery module 100. The module frame 200 may be made of a metal material having high strength.

[0035] The module frame 200 may have various structures. As an example, the module frame 200 may be a mono-frame. The mono-frame may be a metal plate material with an upper surface, a lower surface, and both side surfaces integrated together. As another example, the module frame 200 may have a structure in which a U-shaped frame and an upper plate (upper surface) are combined together. The U-shaped frame may be a metal plate material with a lower plate (bottom surface) and side plates (both side surfaces) combined or integrated together. In addition, the module frame 200 may have a structure in which an L-shaped frame is combined together, or may have various structures not described in the above example.

[0036] The module frame 200 may have an internal space in which the battery cell stack 120 may be housed. More specifically, the module frame 200 may include a top surface, a bottom surface, and both side surfaces. Both ends of the module frame 200 in the length direction may be open and may be covered by end plates 220, which will be described later.

[0037] A plurality of vent holes (not shown) may be formed on one surface, preferably the top surface, of the module frame 200. If a fire occurs in a battery cell 110 inside the module frame 200, gas and flames can be quickly discharged through the vent holes.

[0038] The bus bar frames 300 may be arranged on both sides of the battery cell stack 120 in the overall length direction. At least one bus bar 310 may be attached to the bus bar frame 300, and each bus bar 310 may be connected to an electrode lead 111 of a battery cell 110. The bus bar 310 may be configured to electrically connect the plurality of battery cells 110 to an external device.

[0039] The battery module 100 may further include an end plate 220 .

[0040] The end plates 220 may be disposed on the outer sides of the bus bar frame 300. In other words, the bus bar frame 300 may be disposed between the battery cell stack 120 and the end plates 220.

[0041] The end plates 220 may be coupled to the module frame 200. The end plates 220 may cover both open ends of the module frame 200. Openings 220H may be formed in the end plates 220, and the bus bars 310 may be electrically connected through the openings 220H. That is, the bus bars 310 of one battery module 100 may be electrically connected to another battery module 100 or a BDU (Battery Disconnect Unit) through the openings 220H.

[0042] FIG. 3 is a front view of a battery cell according to one embodiment of the present invention.

[0043] As described above, the battery cell 110 may be manufactured by housing the electrode assembly in a cell case and then sealing the cell case by heat sealing. The cell case may be a pouch-type battery case manufactured by molding a laminate sheet.

[0044] More specifically, the cell case may include a receiving portion 113 for receiving an electrode assembly and a sealing portion 116 located around the receiving portion 113. More specifically, the cell case may include a pair of cases connected to a bridge 115. At least one of the pair of cases may have a recessed receiving portion 113, and the peripheral area of ​​the receiving portion 113 may form a terrace. When the bridge 115 is folded with the electrode assembly received in the receiving portion 113, the terraces of the pair of cases may be sealed on three sides. That is, the terraces of the pair of cases may be sealed by heat sealing while abutting each other to form the sealing portion 116. However, the present invention is not limited thereto, and the pair of cases may be separate members without being connected by the bridge 115. In this case, the terraces of the pair of cases may be abutting each other and may be sealed on four sides by heat sealing to form the sealing portion 116. Such a cell case configuration is well known and should be easily understood by those skilled in the art.

[0045] The sealing portion 116 of the cell case may include a pair of first sealing portions 117 located on both sides of the storage portion 113 in the overall length direction, and a second sealing portion 118 connecting the pair of first sealing portions 117 and located on one side of the storage portion 113 in the overall width direction.

[0046] The electrode lead 111 may protrude to the outside of the cell casing through the first sealing portion 117. That is, the electrode lead 111 may be a portion of the second sealing portion 118 from which the electrode lead 111 does not protrude.

[0047] The second sealing portion 118 may be folded at least once to increase the energy density of the battery cell 110. Preferably, the second sealing portion 118 may be double-side folded (DSF).

[0048] The first sealing portion 117 may extend in the direction of approximately the entire width of the battery cell 110. The second sealing portion 118 may extend in the direction of approximately the entire length of the battery cell 110. The second sealing portion 118 may be located on the opposite side of the bridge 115.

[0049] The battery cell 110 may be provided with at least one fixing member T for fixing the second sealing portion 118 in the folded state. For example, the fixing member T may be an adhesive tape.

[0050] FIG. 4 is an enlarged partial perspective view of a portion of the battery cell stack and the bus bar frame shown in FIG. 3 , FIG. 5 is a perspective view of the bus bar frame shown in FIG. 4 viewed from another direction, and FIG. 6 is a cross-sectional view illustrating a stopper and its surrounding configuration according to an embodiment of the present invention.

[0051] Meanwhile, with the recent increase in demand for batteries requiring high capacity, such as batteries for electric vehicles, the rated capacity of pouch-type secondary batteries has increased, which has led to an increase in the size and weight of electrode assemblies. However, as the size and weight of electrode assemblies increase, the electrode assemblies are more likely to move and damage the cell casing or penetrate the cell casing when subjected to external impact. Such cell casing damage can lead to electrolyte leakage or deformation of the electrode assembly, resulting in serious problems with battery performance and safety.

[0052] In particular, the second sealing portion 118 of the cell case sealing portion 116 is relatively less likely to be damaged or pierced because it is long, folded at least once, and has a fixing member T attached thereto. On the other hand, the first sealing portion 117 is relatively less likely to be damaged or pierced because it is short and therefore the impact force applied by the electrode assembly per unit length may be large, and the electrode lead 111 protrudes from the first sealing portion 117, so it may be relatively more likely to be damaged or pierced.

[0053] To prevent the electrode assembly of the battery cell 10 from coming out of position due to an external impact, which could damage or penetrate the sealing portion 116 of the cell case, particularly the first sealing portion 117, the battery module 100 according to an embodiment of the present invention may include a stopper 400 configured to absorb impact applied to the battery cell 10. The stopper 400 can absorb impact by elastically deforming when hit by the battery cell 10.

[0054] The stopper 400 may be disposed between the plurality of battery cells 10 and the bus bar frame 300 .

[0055] The stopper 400 may be coupled to the bus bar frame 300. More specifically, the stopper 400 may be coupled to the inner side of the bus bar frame 300, and the bus bar 310 may be coupled to the outer side of the bus bar frame 300. Thus, the stopper 400 may be installed at a precise position on one side of the plurality of battery cells 110 while being fastened to the bus bar frame 300.

[0056] The stopper 400 can come into contact with the battery cell 110. The stopper 400 can absorb an impact applied to the battery cell 110 in a state where the battery cell 110 is in contact with the stopper 400.

[0057] Alternatively, the stopper 400 may be spaced apart from the battery cell 110 at a predetermined distance in the overall length direction of the battery cell 110, i.e., in the second direction (e.g., the direction parallel to the X-axis). In this case, when an impact is applied to the battery cell 110, the battery cell 110 may hit the stopper 400, and the stopper 400 can absorb the impact.

[0058] The stopper 400 may extend long in the overall width direction of the battery cell 110. That is, the stopper 400 may have a bar shape that is long in a third direction (e.g., a direction parallel to the Z axis) parallel to the overall width direction of the battery cell 110.

[0059] The length of the stopper 400 may correspond to the overall width of the battery cell 110. That is, the length of the stopper 400 may be the same as or similar to the overall width of the battery cell 110. The length of the stopper 400 may be longer than the length of the slits 300S formed in the bus bar frame 300. As a result, the stopper 400 can absorb impacts overall in the overall width direction of the battery cell 110.

[0060] A plurality of stoppers 400 may be provided so as to be arranged at regular intervals in the direction in which the plurality of battery cells 110 are stacked, that is, in the first direction (for example, a direction parallel to the Y axis).

[0061] A portion of each stopper 400 may face one battery cell 110, and another portion may face another battery cell 110 adjacent to the one battery cell 110. The stoppers 400 may be formed in a convex shape toward the plurality of battery cells 110. This allows the electrode leads 111 of each battery cell 110 to easily enter between the plurality of stoppers 400, and shocks applied to the battery cells 110 can be stably absorbed.

[0062] The bus bar frame 300 may be formed with a plurality of slits 300S that are open toward the spaces between the plurality of stoppers 400 and through which the electrode leads 111 pass. The bus bar 310 attached to the bus bar frame 300 may also be formed with slits 310S that face the slits 300S formed in the bus bar frame 300.

[0063] Therefore, the electrode lead 111 of each battery cell 110 passes between the plurality of stoppers 400, and sequentially passes through the slits 300S formed in the bus bar frame 300 and the slits 310S formed in the bus bar 310, and can be welded to the outer surface of the bus bar 310.

[0064] FIG. 7 is a schematic diagram of a stopper according to one embodiment of the present invention.

[0065] The stopper 400 according to an embodiment of the present invention may be an elastic body or a sponge body. The stopper 400 may be integrally formed. The stopper 400 can elastically deform to absorb impacts applied to the battery cell 110.

[0066] The stopper 400 according to this embodiment has the advantage of being simple in structure and low in manufacturing cost.

[0067] FIG. 8 is a schematic diagram of a stopper according to another embodiment of the present invention.

[0068] A stopper 400 ′ according to another embodiment of the present invention may include an outer covering 410 made of an elastic material or a sponge material, and a breaking member 420 disposed inside the outer covering 410 .

[0069] The exterior material 410 may be formed in a convex shape facing the battery cell 110. The exterior material 410 may have an internal space in which the breaking member 420 is housed. When an impact is applied by the battery cell 110, the exterior material 410 can elastically deform to absorb the impact.

[0070] The breaking member 420 may be a shock absorbing member that absorbs the shock while breaking due to the impact. Because the breaking member 420 is broken irreversibly, the reaction force or resilience that the stopper 400′ applies to the battery cell 110 may be minimized.

[0071] The breaking member 420 may be made of any material suitable for breaking and absorbing impact, without limitation. For example, the breaking member 420 may be made of a plastic material.

[0072] A plurality of breaking members 420 may be provided at predetermined intervals along the length of the stopper 400', thereby increasing the impact absorption effect of the stopper 400'.

[0073] The breaking member 420 may have a zigzag shape. More specifically, the breaking member 420 may have a zigzag shape so as to intersect with the imaginary line L multiple times. The imaginary line L may be parallel to the overall length direction of the battery cell 110, i.e., the second direction (e.g., the direction parallel to the X-axis). Therefore, when the battery cell applies an impact to the exterior material 410 in the second direction, the breaking member 420 can be broken reliably as a whole. As a result, the breaking member 420 can effectively absorb the impact applied to the battery cell 110.

[0074] In the case of the stopper 400' according to this embodiment, the breaking member 420 absorbs the impact while breaking, which is advantageous in that the amount of impact absorption is large and the reaction force applied to the battery cell 110 can be minimized.

[0075] FIG. 9 is a schematic view of another stopper according to yet another embodiment of the present invention.

[0076] A stopper 400 ″ according to yet another embodiment of the present invention may include an outer covering 410 made of an elastic material or a sponge material, and an elastic member 430 disposed inside the outer covering 410 .

[0077] The exterior material 410 may be formed in a convex shape facing the battery cell 110. The exterior material 410 may have an internal space in which the elastic member 430 is housed. When an impact is applied by the battery cell 110, the exterior material 410 can elastically deform to absorb the impact.

[0078] The elastic member 430 may be a shock absorbing member that absorbs the shock while being compressed by the shock.

[0079] A plurality of elastic members 430 may be provided at predetermined intervals along the length of the stopper 400'', thereby increasing the impact absorption effect of the stopper 400''.

[0080] The elastic member 430 may be a spring that is elastically deformed in a direction parallel to the overall length of the battery cell 110. That is, the elastic member 430 can be stretched and compressed in a direction parallel to the second direction (e.g., a direction parallel to the X-axis).

[0081] As a result, the elastic member 430 can effectively absorb the impact applied to the battery cell 110. In addition, it is easy to design the elastic member 430 so that the reaction force applied to the battery cell 110 by the elastic member 430 gradually decreases.

[0082] In the case of the stopper 400'' according to this embodiment, the elastic member 430 absorbs the impact while being compressed, which has the advantage that the amount of impact absorption is large and the reaction force applied to the battery cell 110 can be gradually reduced.

[0083] The above description is merely an illustrative example of the technical concept of the present invention, and various modifications and variations may be made by a person having ordinary skill in the art to which the present invention pertains without departing from the essential characteristics of the present invention.

[0084] Therefore, the embodiments disclosed in the present invention are intended to illustrate, rather than limit, the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by such embodiments.

[0085] The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent range thereof should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0086] 100 battery modules 110 battery cells 111 Electrode lead 113 Storage section 116 Sealing part 117 First sealing section 118 Second sealing part 120 Battery cell stack 200 Module Frame 220 End Plate 300 Busbar Frame 310 Busbar 400 Stopper 410 Exterior materials 420 Breaking Member 430 Elastic Members

Claims

1. Module frame; a plurality of battery cells housed within the module frame and equipped with electrode leads; a bus bar frame having bus bars mounted thereon, the bus bars being disposed on one side of the plurality of battery cells and to which the electrode leads are connected; and a stopper disposed between the plurality of battery cells and the bus bar frame and configured to absorb an impact applied to the battery cells; Including, The stopper is an outer covering material having an elastic or spongy material; and A battery module including an impact absorbing member disposed inside the exterior material.

2. The battery module according to claim 1 , wherein the stopper is elastically deformed when struck by the battery cell.

3. a plurality of stoppers are provided at regular intervals in a stacking direction of the plurality of battery cells; The battery module according to claim 1 , wherein a portion of each stopper faces one battery cell and another portion faces another battery cell adjacent to the one battery cell.

4. The battery module according to claim 1 , wherein the stopper extends in a width direction of the battery cell.

5. The battery module according to claim 1 , wherein the stopper is formed in a convex shape facing the plurality of battery cells.

6. The battery module according to claim 1 , wherein the stopper is coupled to the bus bar frame.

7. a plurality of stoppers are provided at regular intervals in a stacking direction of the plurality of battery cells; The battery module according to claim 1 , wherein the bus bar frame has a plurality of slits formed therein, the slits being open toward the spaces between the plurality of stoppers and through which the electrode leads pass.

8. The battery module according to claim 7 , wherein the length of the stopper is longer than the length of the slit.

9. The battery module according to claim 1 , wherein the length of the stopper corresponds to the overall length of the battery cell.

10. The impact absorbing member is The battery module according to claim 1 , wherein the breaking member is irreversibly broken by an impact.

11. The breaking member is The battery module according to claim 10 , wherein the battery module has a zigzag shape so as to intersect a virtual line parallel to the overall length of the battery cells multiple times.

12. The impact absorbing member is The battery module according to claim 1 , wherein the battery module is an elastic member that is compressed by an impact.

13. The battery module according to claim 12 , wherein the elastic member is a spring that is elastically deformed in a direction parallel to the overall length of the battery cell.

14. The impact absorbing member is The battery module according to claim 1 , wherein a plurality of the stoppers are provided at predetermined intervals along the length of the stoppers.

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