Battery pack and vehicle

Abstract

The utility model provides a battery pack and a vehicle. The battery pack comprises a box body and a plurality of battery cells arranged along a first direction, and the battery cells are arranged in the box body; the expansion beam and the battery cell are arranged in the first direction, the expansion beam is installed in the box body, the expansion beam is provided with a first side face and a second side face which are arranged in the first direction, the first side face is arranged opposite to the battery cell, the box body is provided with a box wall opposite to the expansion beam, and the second side face is used for being connected with the box wall. According to the battery pack provided by the utility model, the expansion force borne by the expansion beam can be reduced, and the risk of connection failure of the expansion beam and the box body is reduced.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to battery packs and vehicles. Background Technology

[0002] Expansion beams are structural components inside battery packs used to manage the expansion forces and internal pressure of individual battery cells. During charging and discharging, the cells expand, and expansion beams can effectively absorb and disperse these expansion forces, reduce stress concentration inside the battery pack, and prevent damage to the cells and the battery pack structure.

[0003] In related technologies, the periphery of the expansion beam is welded to the housing. However, along the expansion direction of the battery cell, the expansion beam and the housing are spaced apart. As the battery pack is used, the expansion force of the battery cell gradually increases. Eventually, the expansion force of multiple rows of battery cells will all be applied to the expansion beam, resulting in a significant risk of failure in the weld connection between the expansion beam and the housing. Utility Model Content

[0004] The present invention provides a battery pack and vehicle that can reduce the expansion force borne by the expansion beam itself and reduce the risk of failure of the connection between the expansion beam and the housing.

[0005] In a first aspect, embodiments of the present invention provide a battery pack, the battery pack comprising:

[0006] Box;

[0007] Multiple battery cells arranged along a first direction are installed inside the housing; and

[0008] An expansion beam, arranged along a first direction with the battery cell, is installed inside the housing. The expansion beam has a first side and a second side arranged along the first direction. The first side is disposed opposite to the battery cell. The housing has a housing wall opposite to the expansion beam. The second side is used to connect with the housing wall.

[0009] In one embodiment, a connector is also included, the connector comprising a first connecting surface and a second connecting surface opposite each other, the first connecting surface being connected to the second side surface and the second connecting surface being connected to the box wall.

[0010] In one embodiment, the connector is also configured to deform under stress to absorb at least a portion of the pressure.

[0011] In one embodiment, the connector is interference-fitted with the expansion beam.

[0012] In one embodiment, the housing includes a first sidewall and a second sidewall, the first sidewall and the second sidewall being arranged along a second direction, the second direction being perpendicular to the first direction;

[0013] The expansion beam includes a first connecting end and a second connecting end. The first connecting end is connected to the first side wall, and the second connecting end is connected to the second side wall. The first side wall and the second side wall are located between the first connecting end and the second connecting end.

[0014] In one embodiment, the housing further includes a bottom wall located between the first side wall and the second side wall, and the expansion beam includes a third connecting end disposed opposite to the bottom wall, the third connecting end being connected to the bottom wall.

[0015] In one embodiment, the expansion beam further includes a fourth connecting end disposed opposite to the third connecting end, the fourth connecting end extending in a direction away from the bottom wall, and the distance between the second side and the box wall gradually increasing along the direction from the third connecting end to the fourth connecting end.

[0016] In one embodiment, the cross-sectional area of ​​the connector gradually increases along the direction from the third connection end to the fourth connection end.

[0017] In one embodiment, the connector includes foam.

[0018] In one embodiment, the second side is welded to the box wall.

[0019] Secondly, embodiments of the present invention provide a vehicle including the aforementioned battery pack.

[0020] The beneficial effects of the embodiments of this utility model are as follows:

[0021] In an embodiment of this invention, the battery pack has multiple battery cells arranged along a first direction. Typically, the battery cells expand along their arrangement direction; that is, the expansion direction of the internal battery cells of the battery pack is the first direction. An expansion beam is provided, with its second side connected to the casing. Thus, when the battery pack expands, pressure is applied to the expansion beam along the first direction from its first side, causing the expansion beam to deform. Because the second side is connected to the casing wall, the expansion beam can transfer some of the pressure to the casing. This reduces the expansion force borne by the expansion beam itself, lowering the risk of weld failure between the expansion beam and the casing. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1This is a schematic diagram of the structure of one embodiment of the battery pack provided by this utility model;

[0024] Figure 2 yes Figure 1 Cross-sectional view;

[0025] Figure 3 yes Figure 1 A schematic diagram of part of the structure;

[0026] Figure 4 yes Figure 3 Cross-sectional view;

[0027] Figure 5 yes Figure 3 Top view;

[0028] Figure 6 yes Figure 5 A cross-sectional view along the AA direction;

[0029] Figure 7 yes Figure 3 A three-dimensional image with parts of the structure removed;

[0030] Figure 8 yes Figure 7 A magnified view of a portion at point A;

[0031] Figure 9 yes Figure 7 A magnified view of a portion at point B;

[0032] Figure 10 yes Figure 7 Cross-sectional view;

[0033] Figure 11 yes Figure 10 A magnified view of a portion at point C;

[0034] Figure 12 yes Figure 10 A magnified view of a portion of point D.

[0035] Explanation of reference numerals in the attached figures:

[0036] 10. Box body; 101. Box wall; 11. First side wall; 13. Second side wall; 15. Bottom wall;

[0037] 20. Battery cells;

[0038] 30. Expansion beam; 31. First side; 33. Second side; 35. First connecting end; 37. Second connecting end; 38. Third connecting end; 39. Fourth connecting end;

[0039] 50. Connector; 51. First connecting surface; 53. Second connecting surface. Detailed Implementation

[0040] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0041] An expansion beam is a structural component inside a battery pack used to manage the expansion force and internal pressure of individual battery cells. During charging and discharging, the cells expand, and the expansion beam effectively absorbs and disperses these expansion forces, reducing stress concentration within the battery pack and preventing damage to the cells and the overall battery pack structure. In related technologies, the periphery of the expansion beam is welded to the casing. However, along the expansion direction of the cells, the expansion beam and the casing are spaced apart. As the battery pack is used, the expansion force of the cells gradually increases, and eventually, the expansion force of multiple rows of cells will all be applied to the expansion beam, leading to a significant risk of failure at the weld connection between the expansion beam and the casing.

[0042] To address the aforementioned problems, firstly, this application provides a battery pack. Please refer to... Figure 1 The battery pack may include a housing 10 and a cell assembly. The housing 10 is used to house the cell assembly. Please refer to... Figure 5 as well as Figure 6 A battery cell assembly may include multiple battery cells 20, which are arranged along a first direction. When multiple battery cells 20 of a battery pack are arranged along the first direction, the battery cell assembly typically undergoes significant expansion along its arrangement direction, leading to stress concentration within the battery pack and potentially causing damage to the battery cells and other structures within the battery pack.

[0043] To absorb and disperse these expansion forces, reduce stress concentration inside the battery pack, and prevent damage to the cells and battery pack structure, please combine... Figure 2 An expansion beam 30 is provided. Multiple battery cells 20 are arranged along a first direction, and the expansion beam 30 is also arranged along the first direction, with the expansion beam 30 installed inside the housing 10. In this way, when the battery cells 20 of the battery pack expand, the expansion beam 30 can absorb and disperse these expansion forces. By absorbing the expansion of the battery cells 20, the expansion beam 30 can maintain the overall structural stability of the battery pack and extend its service life. Specifically, the expansion beam 30 can absorb part of the expansion force through its own deformation.

[0044] Please combine Figure 3 , Figure 4 , Figure 5 as well as Figure 6 In this embodiment, the expansion beam 30 has a first side surface 31 and a second side surface 33 arranged along a first direction. That is, the first side surface 31 and the second side surface 33 are arranged along the expansion direction of the battery cell 20 of the battery pack. The first side surface 31 is arranged opposite to the battery cell 20. When the battery cell 20 of the battery pack expands, it will apply pressure or expansion force to the first side surface 31 of the expansion beam 30, thereby causing the expansion beam 30 to deform and absorb part of the expansion force.

[0045] When the cell 20 is not expanding, the cell 20 may be spaced apart from or in contact with the first side surface 31. In some embodiments, the cell 20 is attached to the first side surface 31, so that the expansion beam 30 can more fully absorb the expansion force applied by the cell 20. When the cell 20 expands, at least a portion of the cell 20 will contact and abut against the first side surface 31, thereby transmitting the expansion force to the expansion beam 30.

[0046] Since the housing 10 has a wall 101 opposite to the expansion beam 30, the second side 33 is used to connect to the wall 101. That is, the expansion beam 30 is connected to the wall 101 of the housing 10 via the second side 33, allowing the expansion beam 30 to transfer part of the expansion force to the wall 101 of the housing 10, thus enabling the housing 10 to share some of the expansion force. It should be noted that the second side 33 can be connected to the wall 101, for example, by welding, bonding, screwing, etc. The second side 33 can also be connected to the wall 101 via connectors.

[0047] In related technologies, because the expansion beam and the housing are spaced apart along the expansion direction of the battery cell, the expansion force of the battery cell is entirely applied to the expansion beam, resulting in a significant risk of failure at the weld connection between the expansion beam and the housing. In this application, the expansion beam 30 can transfer part of the expansion force to the housing wall 101 of the housing 10 via its second side 33, thereby allowing the housing 10 to share some of the expansion force. Therefore, compared to related technologies, this application can transfer part of the expansion force to the housing wall 101, and then to the housing 10 and the welds on the housing 10. By absorbing part of the expansion force through the housing 10 and its welds, the risk of connection failure between the expansion beam and the housing is reduced.

[0048] Please combine Figure 11 as well as Figure 12In some embodiments, the battery pack provided in this application further includes a connector 50, which includes a first connecting surface 51 and a second connecting surface 53 opposite to each other. The first connecting surface 51 is connected to the second side surface 33, and the second connecting surface 53 is connected to the casing wall 101.

[0049] In these embodiments, the expansion beam 30 is connected to the box wall 101 via the connector 50, so that the expansion force of the battery cell 20 can be transmitted to the box wall 101 through the expansion beam 30 and the connector 50, thereby transferring part of the expansion force to the box body 10 and its welds.

[0050] In some embodiments, the connector 50 is also configured to deform under stress to absorb at least a portion of the pressure.

[0051] In the above embodiments, the connector 50 can transfer part of the expansion force transmitted to the expansion beam 30 to the box wall 101, thereby enabling the box body 10 and the welds on the box body 10 to share part of the expansion force. In these embodiments, the connector 50 can also be used to deform under stress to absorb at least part of the pressure. That is, when the expansion force is transmitted to the connector 50, the connector 50 can also deform to absorb part of the expansion force, thereby better protecting the stable connection between the expansion beam 30 and the box body 10.

[0052] The connector 50 can be more easily deformed than the expansion beam 30. The connector 50 can be made of porous structure such as foam, hollow structure, or elastic structure such as spring. In this way, the connector 50 can be easily deformed, thereby absorbing part of the expansion force.

[0053] In some embodiments, the connector 50 is interference-fitted with the expansion beam 30. In these embodiments, the connector 50 is positioned between the second side 33 of the expansion beam 30 and the box wall 101, and is in an interference-fitted state with the expansion beam 30. It is easily understood that the connector 50 is also in an interference-fitted state with the box wall 101, thereby ensuring sufficient contact between the connector 50 and the expansion beam 30, and between the connector 50 and the box wall 101. This allows the expansion beam 30 to more effectively transfer the expansion force to the connector 50, enabling the connector 50 to better absorb the expansion force and better transfer it to the box wall 101.

[0054] Please combine Figure 7 , Figure 8 as well as Figure 9In some embodiments, the housing 10 includes a first sidewall 11 and a second sidewall 13, which are arranged along a second direction perpendicular to the first direction. The expansion beam 30 also includes a first connecting end 35 and a second connecting end 37, whereby the first connecting end 35 is connected to the first sidewall 11 and the second connecting end 37 is connected to the second sidewall 13. The first side surface 31 and the second side surface 33 are located between the first connecting end 35 and the second connecting end 37.

[0055] The first connecting end 35 can be connected to the first sidewall 11 by welding, screwing, bonding, or other methods. The second connecting end 37 can be connected to the second sidewall 13 by welding, screwing, bonding, or other methods.

[0056] In some examples, the first connecting end 35 may be welded to the first sidewall 11, and the second connecting end 37 may be welded to the second sidewall 13.

[0057] Please combine Figure 10 as well as Figure 12 In some embodiments, the housing 10 further includes a bottom wall 15 located between the first side wall 11 and the second side wall 13, and the expansion beam 30 includes a third connecting end 38 disposed opposite to the bottom wall 15, the third connecting end 38 being connected to the bottom wall 15.

[0058] The third connecting end 38 can be connected to the bottom wall 15 by welding, screwing, bonding, or other methods. In some examples, the third connecting end 38 can be welded to the bottom wall 15.

[0059] In some implementation methods, please refer to Figure 10 , Figure 11 as well as Figure 12 The expansion beam 30 also includes a fourth connection end 39 disposed opposite to the third connection end 38. The fourth connection end 39 extends in a direction away from the bottom wall 15. Along the direction from the third connection end 38 to the fourth connection end 39, the distance between the second side 33 and the box wall 101 gradually increases.

[0060] In this embodiment, the distance between the second side 33 and the housing wall 101 gradually increases along the direction from the third connecting end 38 to the fourth connecting end 39. A connector 50 is installed between the second side 33 and the housing wall 101, connecting the second side 33 and the housing wall 101. Therefore, as the distance between the second side 33 and the housing wall 101 gradually increases, it means that the connectors between the second side 33 and the housing wall 101 gradually become more numerous and thicker as they approach the fourth connecting end 39. Since the main deformation area of ​​the battery cell 20 is in the upper middle part, meaning that the upper middle part of the battery cell 20 will exert greater pressure or expansion force on the expansion beam, making the connection between the expansion beam near the fourth connecting end 39 and the housing 10 prone to breakage, this application places a thicker connector in the upper middle part of the battery cell 20, i.e., near the fourth connecting end 39, so that the pressure exerted on the expansion beam by the upper middle part of the battery cell 20 can be more effectively transmitted to the connectors and the housing 10. This reduces the expansion force borne by the expansion beam near the fourth connection end 39, thus lowering the risk of connection failure between the expansion beam and the box 10.

[0061] In some embodiments, the distance between the second side 33 and the box wall 101 gradually increases along the direction from the third connecting end 38 to the fourth connecting end 39. The cross-sectional area of ​​the connector 50 gradually increases along the direction from the third connecting end 38 to the fourth connecting end 39.

[0062] In some examples, the expansion beam 30 can be trapezoidal, and the connector 50 can also be trapezoidal. The shapes of the expansion beam 30 and the connector 50 are adapted to each other and can form a wedge-shaped structure. By using a trapezoidal expansion beam 30 and a trapezoidal connector 50 to form a wedge-shaped structure, it can be easily pushed into and filled in the gap during assembly.

[0063] The wedge-shaped structure of connector 50, which is larger at the top and smaller at the bottom, allows for a considerable distance to absorb expansion forces even after the upper part is interference-fitted. This enables more efficient use of each part of connector 50 and saves costs.

[0064] In some embodiments, the connector 50 includes foam. Specifically, the foam is a porous material containing numerous air bubbles or cavities, which provide good cushioning. Further, in some embodiments, the connector 50 includes rigid foam, such as polystyrene foam, rigid polyurethane foam, rigid polyvinyl chloride foam, rigid polypropylene foam, rigid polyethylene foam, etc. Rigid foam can absorb more expansion force and, during assembly, can be easily pushed into the filling gap between the expansion beam and the housing.

[0065] In these embodiments, the expansion beam and the housing are connected by foam, which absorbs the expansion force of the battery cell 20 and converts it into the compression deformation of the foam. At the same time, part of the expansion force is transferred to the housing and the weld on the housing through the entire large surface, thus solving the risk of weld fracture of the expansion beam during the final expansion.

[0066] In some embodiments, the second side can be directly welded to the box wall 101. This also allows the expansion force to be transmitted to the box body 10 via the expansion beam.

[0067] In some embodiments, the battery pack can specifically be a CTP (Cell to Pack) type battery pack. CTP technology refers to integrating the battery cells directly into the battery pack, eliminating the module stage found in traditional battery packs. Traditional battery pack structures typically include three layers: cell, module, and pack. In CTP technology, the cells are directly installed within the battery pack, reducing the intermediate module structure, thereby simplifying the battery pack structure and improving space utilization and energy density.

[0068] In CTP-type battery packs, the expansion force of multiple rows of cells will eventually be applied to the expansion beam, making the weld connection between the expansion beam and the casing have a high risk of failure.

[0069] The battery pack using the solution of this application includes multiple battery cells arranged along a first direction. Typically, the battery cells expand along their arrangement direction; that is, the expansion direction of the internal battery cells of the battery pack is the first direction. An expansion beam is provided, with its second side 33 connected to the housing. Thus, when the battery pack expands, pressure is applied to the expansion beam along the first direction from its first side 31, causing the expansion beam to deform. Since the second side 33 is connected to the housing wall 101, the expansion beam can transfer some of the pressure to the housing. This reduces the expansion force borne by the expansion beam itself, lowering the risk of weld failure between the expansion beam and the housing.

[0070] Secondly, this application also provides a vehicle that includes a battery pack. This vehicle possesses all the beneficial effects of the aforementioned battery pack, which will not be elaborated upon herein.

[0071] The vehicle may be a gasoline-powered vehicle, a plug-in hybrid electric vehicle, or a new energy vehicle, etc., and this disclosure does not make any specific restrictions.

[0072] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A battery pack, characterized in that, include: Box (10); Multiple battery cells (20) arranged along the first direction are installed inside the housing (10); as well as An expansion beam (30) arranged along a first direction with the battery cell (20) is installed inside the housing (10). The expansion beam (30) has a first side (31) and a second side (33) arranged along the first direction. The first side (31) is disposed opposite to the battery cell (20). The housing has a housing wall (101) opposite to the expansion beam (30). The second side (33) is used to connect with the housing wall (101).

2. The battery pack according to claim 1, characterized in that, It also includes a connector (50), which includes a first connecting surface (51) and a second connecting surface (53) opposite to each other. The first connecting surface (51) is connected to the second side surface (33), and the second connecting surface (53) is connected to the box wall (101).

3. The battery pack according to claim 2, characterized in that, The connector (50) is also used to deform under stress to absorb at least part of the pressure.

4. The battery pack according to claim 2 or 3, characterized in that, The connector (50) is interference-fitted with the expansion beam (30).

5. The battery pack according to claim 2, characterized in that, The box (10) includes a first side wall (11) and a second side wall (13), the first side wall (11) and the second side wall (13) are arranged along a second direction, which is perpendicular to the first direction; The expansion beam (30) includes a first connecting end (35) and a second connecting end (37). The first connecting end (35) is connected to the first side wall (11), and the second connecting end (37) is connected to the second side wall (13). The first side (31) and the second side (33) are located between the first connecting end (35) and the second connecting end (37).

6. The battery pack according to claim 5, characterized in that, The box body (10) also includes a bottom wall (15), which is located between the first side wall (11) and the second side wall (13). The expansion beam (30) includes a third connecting end (38) disposed opposite to the bottom wall (15), which is connected to the bottom wall (15).

7. The battery pack according to claim 6, characterized in that, The expansion beam (30) also includes a fourth connection end (39) disposed opposite to the third connection end (38). The fourth connection end extends away from the bottom wall (15). Along the direction from the third connection end (38) to the fourth connection end (39), the distance between the second side (33) and the box wall (101) gradually increases.

8. The battery pack according to claim 7, characterized in that, Along the direction from the third connecting end (38) to the fourth connecting end (39), the cross-sectional area of ​​the connector (50) gradually increases.

9. The battery pack according to claim 2, characterized in that, The connector (50) includes foam.

10. The battery pack according to claim 1, characterized in that, The second side is welded to the box wall (101).

11. A vehicle, characterized in that, Includes the battery pack as described in any one of claims 1 to 10.

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