Battery module and battery pack having the same

Abstract

The application provides a battery module and a battery pack with the same. The battery module comprises end plates and buffer plates, which are distributed at intervals along the length direction of the battery module. The end plates are two in number, and a receiving space is formed between the two end plates. At least one buffer plate is arranged in the receiving space to divide the receiving space into a plurality of placement cavities. At least one of the buffer plates can plastically deform along the length direction of the battery module. A plurality of cell groups are arranged one-to-one corresponding to the plurality of placement cavities, and the cell groups are located in the placement cavities. A plurality of insulating sheets are arranged at the two ends of the cell groups along the length direction, and the insulating sheets are located between the cell groups and the end plates or the buffer plates. Through the technical scheme provided by the application, the problem that the expansion force of the cells causes the overall module to arch upward, resulting in poor structural stability of the battery pack, can be solved.

Description

Technical Field

[0001] This application relates to the field of battery pack technology, and more specifically, to a battery module and a battery pack having the same. Background Technology

[0002] A battery module is formed by combining multiple cells in a reasonable way. The 1P12S and 1P13S module stacking solutions currently on the market integrate multiple cells through simple series or parallel structures. Although they can provide a certain amount of energy output, their energy density and capacity are limited in the context of increasing energy demand, and the module energy is relatively small.

[0003] To increase energy density, the capacity of a single module can be increased by increasing the number of cells connected in series. However, as the number of cells in series increases, the length of the module also increases. With each use, the battery's expansion force increases, which may cause the module to arch upwards. If the upward deformation exceeds the internal space limit of the battery pack, it can lead to damage to the top cover of the battery pack. This affects the structural stability and lifespan of the battery pack and may also cause safety risks such as short circuits and thermal runaway. Utility Model Content

[0004] The main objective of this application is to provide a battery module and a battery pack having the same, in order to solve the problem in the related technology that the expansion force of the battery cells causes the module to arch upwards, resulting in poor structural stability of the battery pack.

[0005] To achieve the above objectives, according to one aspect of this application, a battery module is provided, comprising: end plates and buffer plates, spaced apart along the length of the battery module; two end plates, forming a receiving space between the two end plates; at least one buffer plate disposed within the receiving space to divide the receiving space into multiple placement cavities; at least one buffer plate capable of plastic deformation along the length of the battery module; multiple cell groups, each corresponding to one of the multiple placement cavities, the cell groups being located within the placement cavities; the cell groups comprising multiple cells, the multiple cells being stacked sequentially along the length of the battery module; and multiple insulating sheets disposed at both ends of the cell groups along the length of the cell groups, the insulating sheets being located between the cell groups and the end plates or buffer plates.

[0006] Furthermore, at least one insulating sheet has an extension on the side facing the battery cell, the extension extending along the length direction of the battery module, and the extension wrapping around part of the battery cell.

[0007] Furthermore, the insulating sheet includes a body and an edge. The body is fixedly connected to the battery cell located at the end of the battery cell assembly on one side along the length direction of the battery cell assembly, and the body is fixedly connected to the end plate or buffer plate on the other side along the length direction of the battery cell assembly. The edge is provided on the side of the body facing the battery cell located at the end of the battery cell assembly and is provided on the edge of the body, forming an extension.

[0008] Furthermore, the edge banding includes a top section and two side sections, with the two side sections respectively located at both ends of the top section along its length. The top section overlaps the top of the battery cell, and the side sections overlap the outer wall of the battery cell along its longitudinal direction.

[0009] Furthermore, the top section has a clearance portion on the side of the terminal post facing the battery cell, which is used to avoid the terminal post.

[0010] Furthermore, a reinforcing rib is provided on the side of the edging away from the battery cell, and the reinforcing rib extends along the length of the battery module.

[0011] Furthermore, the insulating sheet is formed by injection molding, the end plate is formed by die casting, and the buffer plate is formed by extrusion.

[0012] Furthermore, the buffer plate is provided with multiple through holes, which penetrate the buffer plate along its longitudinal direction.

[0013] Furthermore, the battery module also includes a steel strip, which is sleeved on the outer periphery of the battery cell and the end plate. The extension direction of the steel strip is the same as the length direction of the battery module. The end plate has a limiting groove, which is correspondingly set with the steel strip. Part of the steel strip is located in the limiting groove to limit the relative position of the steel strip and the battery cell assembly.

[0014] Furthermore, the cross-sectional area of ​​the buffer plate along the length of the battery module is smaller than the cross-sectional area of ​​the insulating sheet along the length of the battery module.

[0015] Furthermore, the battery module also includes an adhesive layer located between the battery module and the base plate of the battery pack. One side of the adhesive layer is bonded to the bottom of the battery cell, and the other side of the adhesive layer is bonded to the top of the base plate to fix the battery cell to the base plate.

[0016] According to another aspect of this application, a battery pack is provided, the battery pack including a plurality of battery modules, the battery modules being the aforementioned battery modules.

[0017] By applying the technical solution of this application, the buffer plate can undergo plastic deformation along the length of the battery module when the battery cell expands. The buffer plate absorbs the expansion force of the battery cell assembly through its own deformation. At the same time, the plastic deformation of the buffer plate under compression provides additional expansion space for the battery cell, reducing the possibility of the battery module arching upwards, lowering the risk of failure of the end plate and other fixing structures, and extending the service life of the battery module. Furthermore, the combination of the end plate and the buffer plate can also strengthen the overall structural strength of the battery module, enabling it to fix more battery cells and thus improve the energy of the battery module. Meanwhile, when leakage occurs in the battery cell assembly, the current flowing from the battery cell to the end plate or buffer plate must first flow through the insulating sheet, thus increasing the creepage distance between the battery cell and the end plate or buffer plate, optimizing the insulation performance of the battery cell assembly, and thus improving the electrical safety performance of the entire battery module. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0019] Figure 1 A schematic diagram of the structure of a battery module provided according to an embodiment of this application is shown;

[0020] Figure 2 An exploded view of a battery module provided according to an embodiment of this application is shown;

[0021] Figure 3 A schematic diagram of the structure of the insulating sheet provided according to an embodiment of this application is shown;

[0022] Figure 4 A schematic diagram of the structure of a buffer plate provided according to an embodiment of this application is shown;

[0023] Figure 5 A schematic diagram of the structure of the buffer plate provided according to an embodiment of this application is shown from a top view.

[0024] Figure 6 A schematic diagram of the structure of an end plate provided according to an embodiment of this application is shown.

[0025] The above figures include the following reference numerals:

[0026] 10. End plate; 101. Limiting groove;

[0027] 20. Buffer plate; 201. Through hole; 202. Connecting hole; 203. Connecting rib;

[0028] 30. Battery cell assembly; 31. Battery cell; 32. Terminal post;

[0029] 40. Insulating sheet; 401. Extension; 41. Body; 42. Edge banding; 421. Top section; 4211. Clearance section; 422. Side section; 423. Reinforcing rib;

[0030] 50. Steel strip; 60. Heat insulation pad; 70. Aluminum strip assembly. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0034] like Figure 1 and Figure 2As shown, this embodiment of the present invention provides a battery module, which includes an end plate 10, a buffer plate 20, multiple cell groups 30, and multiple insulating sheets 40. The end plates 10 and buffer plates 20 are spaced apart along the length of the battery module. There are two end plates 10, spaced apart along the length of the battery module, forming a receiving space between them. The two end plates 10 provide fixing force and pre-tightening force to the cell groups 30. At least one buffer plate 20 is provided within the receiving space to divide the receiving space into multiple placement cavities. At least one buffer plate 20 is capable of plastic deformation along the length of the battery module. Multiple cell groups 30 are arranged one-to-one with multiple placement cavities, and each cell group 30 includes multiple cells 31, which are stacked sequentially along the length of the battery module. Multiple insulating sheets 40 are disposed at both ends of the cell groups 30 along the length of the module, and are located between the cell groups 30 and the end plates 10 or buffer plates 20. The battery module extends horizontally, and the length of the cell assembly 30 is the same as that of the battery module. The Y-axis is the length direction of the battery module, i.e., the extension direction. The plane containing the X and Y axes is horizontal, and the Z-axis is vertical, i.e., the longitudinal direction.

[0035] By applying the technical solution of this application, the buffer plate 20 can undergo plastic deformation along the length of the battery module when the cell 31 expands. The buffer plate 20 absorbs the expansion force of the cell assembly 30 through its own deformation. At the same time, after the buffer plate 20 is squeezed and undergoes plastic deformation, it also provides additional expansion space for the cell 31, reducing the possibility of the battery module arching upwards, reducing the risk of failure of the end plate 10 and other fixing structures, and extending the service life of the battery module. Furthermore, the combination of the end plate 10 and the buffer plate 20 can also strengthen the overall structural strength of the battery module, enabling it to fix more cells 31, thereby increasing the energy of the battery module. Meanwhile, when leakage occurs in the cell assembly 30, the current flowing from the cell 31 to the end plate or buffer plate needs to flow through the insulating sheet 40 first. This increases the creepage distance between the cell 31 and the end plate 10 or buffer plate 20, improves the insulation performance of the cell assembly 30, and thus improves the electrical safety performance of the entire battery module.

[0036] In this application, the number of battery cells 31 and buffer plates 20 is not limited and can be selected according to the user's actual needs.

[0037] In this embodiment, there are 26 battery cells 31. A buffer plate 20 is provided between the two end plates 10, that is, the accommodating space has two placement cavities, and 13 battery cells 31 are arranged in one placement cavity. The battery cells 31 are LF314K laminated battery cells.

[0038] like Figure 2 and Figure 3As shown, at least one insulating sheet 40 has an extension 401 on the side facing the battery cell 31. The extension 401 extends along the length direction of the battery module and partially covers the battery cell 31. In this way, when leakage occurs in the battery cell assembly 30, the current flowing through the insulating sheet 40 must also pass through the extension 401, further increasing the creepage distance between the battery cell 31 and the end plate 10 or buffer plate 20, thus optimizing the insulation performance of the battery cell assembly 30 and the electrical safety performance of the battery module.

[0039] In this embodiment, the specific shape of the extension 401 and the degree of wrapping around the battery cell 31 are not limited; they can be selected and adjusted according to actual insulation requirements.

[0040] like Figure 3 As shown, the insulating sheet 40 includes a body 41 and an edge 42. One side of the body 41 along the length of the cell assembly 30 is fixedly connected to the cell 31 located at the end of the cell assembly 30. The other side of the body 41 along the length of the cell assembly 30 is fixedly connected to the end plate 10 or the buffer plate 20. Thus, the body 41 forms a stable insulating layer, effectively isolating the electrical connection between the cell 31 and the end plate 10 or the buffer plate 20, reducing the risk of short circuits due to expansion and deformation of the cell 31. The edge 42 is located on the side of the body 41 facing the cell 31 located at the end of the cell assembly 30, and is situated at the edge of the body 41, forming an extension 401. The edge 42 further enhances the isolation effect; its extension 401 wraps around part of the cell 31, further increasing the creepage distance and improving electrical safety. Simultaneously, the edge 42 also protects the edges of the beginning and end of the cell assembly 30, preventing mechanical damage to the edges of the first or last cell 31 during battery module assembly and use.

[0041] The main body 41 has a rectangular structure, and the structure of the insulating sheet 40 is adapted to the structure of the battery cell 31, which can reduce the waste of assembly space and improve the energy density of the battery module.

[0042] In this application, the perimeter of the edging 42 is not limited. The edging 42 can be set around the edge of the body 41 or on part of the edge of the body 41.

[0043] like Figure 3As shown, the edging 42 includes a top section 421 and two side sections 422. The two side sections 422 are respectively disposed at both ends of the top section 421 along its length. The top section 421 overlaps the top of the cell 31, and the side sections 422 overlap the outer side wall of the cell 31 along its longitudinal direction. If the edging is provided at the bottom of the body 41, there will be gaps between the other cells not wrapped by the insulating sheet 40 and the bottom plate of the battery pack during assembly, requiring additional support structures. This not only requires additional processing of support components but also makes the assembly process more cumbersome and prone to assembly defects. In this embodiment, the edging is not provided at the bottom of the body 41. Thus, during assembly, the bottom of the entire cell assembly 30 directly contacts the bottom plate of the battery pack, reducing the need for additional support components, lowering material costs, simplifying the assembly process, and reducing the defect rate caused by assembly tolerances or operational errors.

[0044] Furthermore, the top section 421 has a clearance portion 4211 on the side facing the terminal post 32 of the cell 31, which is used to avoid obstructing the terminal post 32. This design prevents the insulating sheet 40 from blocking or interfering with the terminal post 32, ensuring that the electrical connection between the cell 31 and other components remains unaffected. Simultaneously, the clearance portion 4211 prevents contact between the insulating material and the terminal post 32, eliminating potential connection problems or increased impedance due to insulating material coverage, thereby guaranteeing the electrical performance and efficiency of the battery module.

[0045] In this application, the specific structure of the avoidance part 4211 is not limited.

[0046] In this embodiment, the clearance portion 4211 is a rectangular slot, and the slot is opened on part of the top section 421. The length of the top section 421 located at both ends of the slot along the battery module direction is the same as that of the side section 422. This design not only facilitates processing and reduces waste, but also improves the structural strength of the insulating sheet 40. Specifically, the battery cell 31 is also provided with other components that need to be clearance, such as a pressure relief valve. The shape of the clearance portion 4211 can be processed according to the actual working conditions.

[0047] In other embodiments, the avoidance part 4211 is slotted only at the location where avoidance is required, that is, multiple small slots are opened on the top section 421, and the small slots correspond one-to-one with the structures that need to be avoided, such as the pole post 32.

[0048] like Figure 3 As shown, a reinforcing rib 423 is provided on the side of the edge 42 away from the cell 31, and the reinforcing rib 423 extends along the length direction of the battery module. The reinforcing rib 423 provides additional support to the edge 42, especially in the length direction of the battery module, which can significantly improve the deformation resistance of the edge 42, provide continuous protection and isolation for the cell 31, and at the same time ensure the structural stability and durability of the entire module.

[0049] In this embodiment, the reinforcing rib 423 consists of multiple parallel strip-shaped protrusions disposed on the side section 422, with the extension direction of the protrusions being the same as the extension direction of the reinforcing rib 423. In other embodiments, the reinforcing rib 423 may be located on the top section 421, and the reinforcing rib 423 may be configured as a block structure or a recessed structure, etc.

[0050] Specifically, the insulating sheet 40 is formed using injection molding, a process that allows for the rapid and precise creation of complex shapes, such as integrated reinforcing ribs and edge banding, while ensuring the material's insulation performance. The end plate 10 is formed using die casting, a process that, while slightly more expensive, offers stable production capacity, high yield, and ensures a strong and stable fixing structure at the head and tail of the module. The buffer plate 20 is formed using extrusion, a process that produces a weaker buffer plate 20 than a die-cast end plate 10, but at a lower cost. This combination of die casting and extrusion reduces costs without compromising the strength of the battery module. The end plates 10 at the front and rear of the battery module provide fixation and pre-tension for the cell assembly 30 and the buffer plate 20. Under increased module expansion force, the buffer plate 20 in the middle can be compressed and deformed by the end plates 10 to reduce upward arching deformation of the module.

[0051] like Figure 4 and Figure 5 As shown, the buffer plate 20 has multiple through holes 201, which penetrate the buffer plate 20 along its longitudinal direction. This design reduces the weight of the buffer plate 20, making the battery pack lighter. Simultaneously, the through holes 201 give the buffer plate 20 a hollow structure, allowing it to deform more easily when compressed, thereby absorbing the force generated by the expansion of the battery cell 31 and reducing the impact of the expansion force on the battery module structure. This deformation absorption capability allows the buffer plate 20 to effectively disperse the stress generated by the expansion of the battery cell 31, improving the mechanical stability and durability of the battery module. Furthermore, the hollow design not only reduces material usage and lowers production costs, but also further increases the allowable expansion space for the battery cell 31, making the battery cell assembly 30 less prone to arching upwards and damaging the battery pack cover.

[0052] The number and specific shape of the through holes 201 are not limited.

[0053] Specifically, the buffer plate 20 has a hollow structure with multiple connecting ribs 203 in the hollow part. The multiple connecting ribs 203 cooperate with the side wall of the buffer plate 20 to form multiple through holes 201. The setting of the connecting ribs 203 not only ensures that the buffer plate 20 has a hollow structure, but also strengthens the structural strength of the buffer plate 20, which can provide a certain pre-tightening force and support force for the battery cell assembly 30.

[0054] like Figure 4 and Figure 5 As shown, the buffer plate 20 is provided with multiple connection holes 202. The connection holes 202 are provided through both ends of the buffer plate 20 in the length direction. The connection holes 202 are connected to the battery pack by fasteners to fix the position of the buffer plate 20 in the battery pack, prevent the buffer plate 20 from longitudinally displacing, and further improve the stability of the battery module.

[0055] In this embodiment, the buffer plate 20 has multiple interconnected sides along the circumference, and rounded corners can be provided between adjacent sides.

[0056] like Figure 2 and Figure 6 As shown, the battery module also includes a steel strip 50, which is sleeved around the outer periphery of the battery cell 31 and the end plate 10. In the circumferential direction of the battery module, the steel strip 50 avoids the reinforcing ribs 423 on the insulating sheet 40 to prevent interference or wear. The extension direction of the steel strip 50 is the same as the length direction of the battery module. The end plate 10 has a limiting groove 101, which corresponds to the steel strip 50. A portion of the steel strip 50 is located within the limiting groove 101 to limit the relative position of the steel strip 50 and the battery cell assembly 30. Through the limiting effect of the steel strip 50, the battery cell assembly 30 can be effectively fixed, reducing its displacement within the battery module. Simultaneously, the cooperation between the limiting groove 101 and the steel strip 50 allows for precise control of the steel strip 50's position, reducing offset or vibration during battery module use or transportation. This ensures a continuous and uniform pre-tensioning effect of the steel strip 50 on the battery cell 31, improving the reliability and service life of the battery module.

[0057] The cross-sectional area of ​​the buffer plate 20 along the length of the battery module is smaller than that of the insulating sheet 40 along the length of the battery module. The outer periphery of the steel strip 50 is typically wrapped with an insulating layer. This design prevents the buffer plate 20 from directly contacting the steel strip 50, reducing wear on the buffer plate 20 and the insulating layer on the steel strip 50 caused by friction, extending the service life of the buffer plate 20 and the steel strip 50, and improving the durability of the battery module.

[0058] In this application, the battery module also includes an adhesive layer located between the battery module and the base plate of the battery pack. One side of the adhesive layer is bonded to the bottom of the battery cell 31, and the other side of the adhesive layer is bonded to the top of the base plate to fix the battery cell 31 to the base plate. The use of the adhesive layer can firmly fix the battery cell 31 to the base plate, effectively restrict the expansion displacement of the battery cell 31 in the vertical direction, reduce the risk of the battery module arching, maintain the structural stability of the battery module, and reduce safety hazards caused by the movement of the battery cell 31.

[0059] Specifically, the adhesive layer is a thermally conductive structural adhesive, which is polyurethane and can be cured at room temperature. It has both conductive and adhesive functions. The thermally conductive structural adhesive is applied between the bottom of the battery module and the liquid cooling plate. After the adhesive cures, it can bond the battery module to the liquid cooling plate while conducting heat, further reducing the longitudinal deformation of the battery module.

[0060] like Figure 1 and Figure 2 As shown, the battery module also includes heat insulation pads 60 and aluminum busbar assemblies 70. There are multiple heat insulation pads 60, which are respectively disposed between adjacent cells 31 to reduce heat transfer between adjacent cells 31. The aluminum busbar assemblies 70 are electrically connected to multiple cell assemblies 30 to realize the series connection of multiple cells 31.

[0061] According to another embodiment of this application, a battery pack is provided, comprising multiple battery modules, wherein the battery modules are the same as those provided in the above embodiment. The aforementioned battery modules effectively solve the problem in the prior art where the expansion force of the battery cells causes the module to arch upwards, resulting in poor structural stability of the battery pack. Battery packs with the aforementioned battery modules also possess the aforementioned advantages.

[0062] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0063] 1. Composite stacking scheme enhances the insulation and structural stability of battery modules: By introducing a buffer plate between the front and rear cells and setting an insulating sheet at the contact point between the cell and the end plate or buffer plate, the edge-wrapping design of the insulating sheet increases the creepage distance, which meets the high energy density stacking requirements of the cells and improves electrical safety.

[0064] 2. Differentiated combination of end plate and buffer plate: Die-cast end plates are used at the ends of the battery module. Their high strength provides a stable fixation and support for the cell assembly. The buffer plate provides space for cell deformation. The two work together to improve the mechanical reliability and safety of the battery module and achieve an optimal balance between cost and performance.

[0065] 3. Application of bottom thermally conductive structural adhesive: Applying thermally conductive structural adhesive to the bottom of the battery module not only enhances the thermal conductivity between the module and the base plate, but also fixes the battery module to the base plate through its adhesive effect. Even under the action of cell expansion force, it can limit the longitudinal deformation of the battery module, reduce the upward arching deformation caused by the expansion of the battery module, and protect the battery pack cover from damage.

[0066] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0067] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0068] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0069] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery module, characterized in that, The battery module includes: End plates (10) and buffer plates (20) are distributed at intervals along the length direction of the battery module. There are two end plates (10), and a receiving space is formed between the two end plates (10). At least one buffer plate (20) is provided in the receiving space to divide the receiving space into multiple placement cavities. At least one of the buffer plates (20) can undergo plastic deformation along the length direction of the battery module. Multiple cell groups (30) are arranged one-to-one with multiple placement cavities. The cell groups (30) are located in the placement cavities. Each cell group (30) includes multiple cells (31), and the multiple cells (31) are stacked sequentially along the length direction of the battery module. Multiple insulating sheets (40) are disposed at both ends of the battery cell assembly (30) along the length direction, and the insulating sheets (40) are located between the battery cell assembly (30) and the end plate (10) or the buffer plate (20).

2. The battery module of claim 1, wherein, At least one of the insulating sheets (40) has an extension (401) on the side facing the cell (31), the extension (401) extending in the length direction of the battery module, and the extension (401) wrapping a portion of the cell (31).

3. The battery module of claim 2, wherein, The insulating sheet (40) includes a body (41) and an edge (42). The body (41) is fixedly connected to the cell (31) located at the end of the cell group (30) on one side along the length direction of the cell group (30). The body (41) is fixedly connected to the end plate (10) or buffer plate (20) on the other side along the length direction of the cell group (30). The edge (42) is disposed on the side of the body (41) facing the cell (31) located at the end of the cell group (30) and is disposed on the edge of the body (41). The edge (42) forms the extension (401).

4. The battery module of claim 3, wherein, The edging (42) includes a top section (421) and two side sections (422). The two side sections (422) are respectively disposed at both ends of the top section (421) in the length direction. The top section (421) overlaps the top of the battery cell (31), and the side sections (422) overlap the outer side wall of the battery cell (31) in the longitudinal direction.

5. The battery module of claim 4, wherein, The top section (421) has a clearance portion (4211) on the side facing the terminal post (32) of the cell (31), the clearance portion (4211) being used to avoid the terminal post (32).

6. The battery module of claim 3, wherein, The side of the edging (42) away from the cell (31) is provided with a reinforcing rib (423), which extends along the length of the battery module.

7. The battery module of claim 1, wherein, The insulating sheet (40) is formed by injection molding, the end plate (10) is formed by die casting, and the buffer plate (20) is formed by extrusion.

8. The battery module of claim 1, wherein, The buffer plate (20) is provided with a plurality of through holes (201), and the plurality of through holes (201) penetrate the buffer plate (20) along the longitudinal direction of the buffer plate (20).

9. The battery module according to claim 1, characterized in that, The battery module also includes a steel strip (50), which is sleeved on the outer periphery of the battery cell (31) and the end plate (10), and the extension direction of the steel strip (50) is the same as the length direction of the battery module. The end plate (10) has a limiting groove (101) which is correspondingly provided with the steel strip (50). Part of the steel strip (50) is located in the limiting groove (101) to limit the relative position of the steel strip (50) and the battery cell assembly (30).

10. The battery module of claim 9, wherein, The cross-sectional area of ​​the buffer plate (20) along the length of the battery module is smaller than the cross-sectional area of ​​the insulating sheet (40) along the length of the battery module.

11. The battery module according to any one of claims 1-10, characterized in that, The battery module also includes an adhesive layer located between the battery module and the base plate of the battery pack. One side of the adhesive layer is bonded to the bottom of the cell (31), and the other side of the adhesive layer is bonded to the top of the base plate to fix the cell (31) on the base plate.

12. A battery pack, characterized by, The battery pack includes multiple battery modules, and the battery modules are the battery modules described in any one of claims 1-11.

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