Battery module and battery pack

Abstract

To provide a battery module and a battery pack.SOLUTION: A battery module and a battery pack are provided. The battery module includes an end plate, a pressure welding bar, and a battery cell. A plurality of battery cells are sequentially arranged along a first direction to form a battery cell group. Two end plates abut on both ends of the battery cell group, respectively. The pressure welding bar includes a pressure welding bar body and a connection assembly. The pressure welding bar body extends along a first direction. The connection assembly is connected to at least one end of the pressure welding bar body in the first direction. The pressure welding bar is pressed against the battery cell group. The connection assembly is movably abutted on a side of the end plate away from the battery cell group.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This application relates to the field of battery technology, and specifically to battery modules and battery packs.

[0002] This application claims the priority of a Chinese patent application with the application number 202323529198.6, which was filed with the Chinese Patent Office on December 22, 2023, and all the contents of the said application are incorporated herein by reference.

Background Art

[0003] With the rapid development of the new energy vehicle market, the safety of the power battery system has become the focus of the industry. The modularization technology of battery modules is an important direction in the integrated design of battery packs. Since battery modules have end plates, side plates, and straps for binding, the structural stability of battery modules is superior to that of CTP (Cell-to-Pack) battery packs.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In related technologies, the modular design methods related to battery modules usually adopt solutions regarding thick end plates and side plates, or lightweight them. As a result, it causes insufficient binding to battery cells, leading to insufficient structural strength throughout the life cycle of the battery module, resulting in irreversible expansion deformation or affecting the cycle life of the battery module.

Means for Solving the Problems

[0005] This application provides a battery module. The battery module includes end plates, compression bars, and battery cells. A plurality of battery cells are arranged in sequence along a first direction to form a battery cell group. Two end plates are respectively abutted against both ends of the battery cell group. The compression bar includes a compression bar body and a connection assembly. The compression bar body extends along the first direction, and the connection assembly is connected to at least one end of the compression bar body in the first direction. The compression bar is pressed against the battery cell group, and the connection assembly is movably abutted against the side of the end plate away from the battery cell group.

[0006] This application further provides a battery pack. The battery pack includes the above-described battery module.

Advantages of the Invention

[0007] The battery pack provided by this application forms a battery cell group by arranging battery cells in sequence along a first direction. Then, two end plates abutted against both ends of the battery cell group and a compression bar connected to the two end plates form the frames of the battery cells in the battery cell group, playing a role in restraining in each direction of the battery cell group. In addition, the compression bar and the end plate are movably abutted by a connection assembly provided at at least one end of the compression bar body. The connection assembly is movably abutted against the end plate, approaching the two end plates close to each other until the battery cell group is tightened, increasing the restraining force along the first direction on the battery cell group. Thereby, the restraining effect in the first direction of the battery cell group is further improved, and then the anti-expansion property in each direction of the battery module is ensured, ensuring that the structure of the battery module is stable and reliable throughout the entire life cycle.

[0008] By installing the above-described battery module, the battery pack provided by this application can ensure the anti-expansion property in each direction of the battery pack and ensure that the structure of the battery pack is stable and reliable throughout the entire life cycle.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0010] In the description of the present application, unless there are explicit regulations and limitations, the terms "connected to each other", "connected", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, an integral body, a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intermediate medium, a communication inside two elements, or an interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in the present application according to specific situations.

[0011] In the present application, unless there are explicit regulations and limitations, the fact that the first feature is "above" or "below" the second feature may include that the first feature is in direct contact with the second feature, or that the first feature is not in direct contact with the second feature and is in contact through other features between them. Also, the fact that the first feature is "above", "above the upper side", or "upper surface" of the second feature indicates that the first feature is directly above and obliquely above the second feature, and that the first feature is higher than the second feature in the horizontal direction. The fact that the first feature is "below", "below the lower side", or "lower surface" of the second feature indicates that the first feature is directly below and obliquely below the second feature, and that the first feature is lower than the second feature in the horizontal direction.

[0012] In the description of this embodiment, terms related to directions or positional relationships such as "up", "down", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the drawings and are for the purpose of simplifying the description and operation. They do not indicate or imply a specific direction, a device or element having a specific orientation configuration and operation, and thus should not be construed as limiting the present application. Furthermore, "first" and "second" are for the purpose of distinction in the description and do not have a special meaning.

[0013] As shown in FIGS. 1 to 2, an embodiment of the present application provides a battery module 10, and the battery module 10 includes an end plate 1, a pressure contact bar 2, and battery cells 3.

[0014] A plurality of battery cells 3 are arranged in sequence along the first direction X to form a battery cell group 4.

[0015] Two end plates 1 are respectively abutted against both ends of the battery cell group 4.

[0016] It should be noted that the shape of the end plate 1 can be adapted to the shape of the battery cell 3. For example, when the battery cell 3 is a rectangular battery cell, the end plate 1 is also rectangular. Furthermore, the dimensions of the end plate 1 can also be adapted to the dimensions of the battery cell 3. By arranging the end plate 1 and the battery cell 3 so that their dimensions match, the binding effect of the end plate 1 on the battery cell 3 can be enhanced.

[0017] As shown in FIG. 3, the pressure contact bar 2 includes a pressure contact bar body 21 and a connection assembly 22. The pressure contact bar body 21 extends along the first direction X, and the connection assembly 22 is connected to at least one end of the pressure contact bar body 21 in the first direction X.

[0018] The pressure contact bar 2 is pressed against the battery cell group 4, and the connection assembly 22 is movably abutted against the side of the end plate 1 away from the battery cell group 4.

[0019] As can be understood, the connection assembly 22 may be connected only to one end of the pressure contact bar body 21 in the first direction X, or may be simultaneously connected to both ends of the pressure contact bar body 21 in the first direction X. When the connection assembly 22 is connected only to one end of the pressure contact bar body 21 in the first direction X, the other end of the pressure contact bar body 21 is connected to the end plate 1 by a fixed connection method, and the end having the connection assembly 22 is movably abutted against the end plate 1. When the connection assembly 22 is simultaneously connected to both ends of the pressure contact bar body 21 in the first direction X, the connection assemblies 22 located at both ends are movably abutted against the two end plates 1 respectively.

[0020] By way of example, as shown in FIGS. 1 to 2, the battery cell 3 is a rectangular battery cell, and a plurality of battery cells 3 are arranged in sequence along the thickness direction to form a battery cell group 4, and the two end plates 1 are respectively abutted against both ends of the battery cell group 4.

[0021] As shown in FIG. 3, the pressure contact bar 2 includes a pressure contact bar body 21 and a connection assembly 22. Here, the pressure contact bar body 21 extends along the first direction X, and the connection assembly 22 is connected to at least one end of the pressure contact bar body 21 in the first direction X. That is, the connection assembly 22 and the pressure contact bar body 21 are integrated, and the two connection assemblies 22 are respectively connected to the two end portions of the pressure contact bar body 21.

[0022] The crimping bar 2 is pressed against the battery cell group 4, and the connection assembly 22 is movably abutted against the side of the end plate 1 away from the battery cell group 4. By pressing the crimping bar 2 against the battery cell group 4 and movably abutting the crimping bar 2 and the end plate 1 by the connection assembly 22, the end plate 1 and the crimping bar 2 are caused to form a frame of the battery cells used to bind the battery cell group 4, and play a role in binding in each direction of the battery cell group 4. On the other hand, the connection assembly 22 provided at the end of the crimping bar body 21 is movably abutted against the end plate 1, so that the end plates 1 at both ends are brought closer to each other until the battery cell group 4 is tightened, increasing the binding force along the first direction X with respect to the battery cell group 4. Thereby, the binding effect of the crimping bar 2 and the end plate 1 in the first direction X with respect to the battery cell group 4 is further improved, and furthermore, the expansion resistance in each direction of the battery module 10 is ensured, and the structure of the battery module 10 is stable and reliable throughout the entire life cycle.

[0023] The pre-tightening force is one of the important indicators in the design of the battery module 10, and has a relatively large impact on the cycle life and initial rigidity of the battery module 10. However, in the related art, the battery module 10 usually adopts a design method of fixing the pre-tightening force. As a result, due to certain errors and variations in the dimensions of the battery cells 3, when the dimensions of the battery cells 3 constituting the battery module 10 change, the design method of fixing the pre-tightening force cannot adjust the initial pre-tightening force of the battery module 10 accordingly.

[0024] In some embodiments, as shown in FIG. 3, the connection assembly 22 includes a pre-tightening member 221 and a connection portion 222. The connection portion 222 is connected to at least one end of the crimping bar body 21, the pre-tightening member 221 is movably connected to the connection portion 222 along the first direction X, and the end of the pre-tightening member 221 away from the connection portion 222 is abutted against the end plate 1.

[0025] That is, the connection part 222 is connected to the compression bar main body 21. The pre-tightening member 221 is connected to the connection part 222 along the first direction X. The end of the pre-tightening member 221 away from the connection part 222 is abutted against the end plate 1, thereby realizing the connection between the compression bar 2 and the end plate 1. At the same time, the pre-tightening member 221 realizes a flexible adjustment of the pre-tightening force of the battery module 10, solves the problem that is likely to occur that the pre-tightening force exceeds or is insufficient when the dimension of the battery cell 3 fluctuates, and also avoids affecting the cycle life due to the pre-tightening force of the battery module 10 exceeding or being insufficient with respect to the standard.

[0026] In some embodiments, as shown in FIG. 5, the end plate 1 is further provided with a convex portion 11 extending along the first direction X, and one end of the convex portion 11 away from the end plate 1 is inserted into the connection part.

[0027] By providing the convex portion 11 on the end plate 1 and inserting one end of the convex portion 11 away from the end plate 1 into the connection part 222, a positioning effect can be provided between the end plate 1 and the compression bar 2, and the connection between the end plate 1 and the compression bar 2 can be realized better.

[0028] Note that the shape of the convex portion 11 may be cylindrical, or may be square cylindrical or other shapes.

[0029] Furthermore, as shown in FIGS. 3-4, the connection part 222 is provided with a connection hole 2221, the convex portion 11 is inserted into a part of the connection hole 2221, and the pre-tightening member 221 penetrates through another part of the connection hole 2221 and abuts against the convex portion 11.

[0030] By inserting the convex portion 11 into the connection hole 2221, the positioning effect is realized. On the other hand, by abutting the pre-tightening member 221 against the convex portion 11 and within the connection hole 2221, the connection between the end plate 1 and the compression bar 2 is realized, and the compactness of the structure is further improved.

[0031] Furthermore, when the battery cell group 4 expands, an outward expansion pressure is generated on the pressure contact bars 2 distributed around the battery cell group 4, increasing the radial force of the pre-fastening member 221 and affecting the pre-fastening adjustment and removal of the pre-fastening member 221. In contrast, the convex portion 11 provided on the end plate 1 realizes the positioning effect and can improve the radial position limiting effect. As a result, when the battery cell group 4 expands and deforms, the radial force of the pre-fastening member 221 when the battery module 10 deforms unevenly can be reduced, and the influence caused by the expansion of the battery cell group 4 can be reduced.

[0032] In some embodiments, the pre-fastening member 221 is screwed into the connection hole 2221.

[0033] The pre-fastening member 221 is screwed into the connection hole 2221, the pre-fastening member 221 is connected to the pressure contact bar 2, and by pressing the end plate 1, the connection between the pressure contact bar 2 and the end plate 1 is realized. Also, the cooperation between the connection hole 2221 and the convex portion 11 realizes the positioning effect, and the pre-fastening member 221 is connected to the connection hole 2221 by a screwing method, facilitating easy flexible adjustment of the pre-fastening force.

[0034] By way of example, the pre-fastening member 221 may be a tightening adjustment bolt, and the connection hole 2221 may be a threaded hole.

[0035] In some embodiments, as shown in FIG. 3, the pressure contact bar body 21 includes a first pressure contact portion 211 and a second pressure contact portion 212. The first pressure contact portion 211 and the second pressure contact portion 212 each extend along the first direction X, the second pressure contact portion 212 is connected to one side of the first pressure contact portion 211, the first pressure contact portion 211 and the second pressure contact portion 212 are respectively pressed against both adjacent sides of the battery cell group, and both sides of the connection assembly 22 are respectively connected to the first pressure contact portion 211 and the second pressure contact portion 212.

[0036] The first crimping part 211 and the second crimping part 212 are firmly pressed against both adjacent sides of the battery cell group 4 respectively. The first crimping part 211 and the second crimping part 212 respectively play a role of binding in different directions of the battery cell group 4, and can increase the structural strength in two directions. Through the cooperation of the plurality of crimping bars 2, the battery cell group 4 forms a more stable whole, and the overall rigidity of the battery module 10 can be significantly improved.

[0037] Furthermore, the connection assembly 22 includes a connection part 222. Both sides of the connection part 222 are respectively connected to the first crimping part 211 and the second crimping part 212. The connection part 222, the first crimping part 211 and the second crimping part 212 are perpendicular to each other.

[0038] As an example, as shown in FIG. 3, the first crimping part 211 and the second crimping part 212 are perpendicular to each other, that is, the crimping bar body 21 has an "L" - shaped structure, and the connection part 222 is perpendicular to the first crimping part 211 and the second crimping part 212 respectively. For the battery cell group 4 composed of rectangular battery cells, the first crimping part 211 and the second crimping part 212 perpendicular to each other can increase the structural strength in two directions. Also, the first crimping part 211, the second crimping part 212 and the connection part 222 perpendicular to each other can provide the effect of positioning and position limitation in three directions of the end plate 1, thereby improving the structural stability of the battery module 10.

[0039] Note that the widths of the first crimping part 211 and the second crimping part 212 may be the same or different. In the actual application process, the widths and relative positions of the first crimping part 211 and the second crimping part 212 may be adjusted according to the degree of the binding effect required in different directions of the battery module 10.

[0040] In some embodiments, at least two crimping bars 2 are installed, and at least two crimping bars 2 are respectively located at the diagonals of the battery cell group 4.

[0041] The crimping bar 2 includes both a first crimping portion 211 and a second crimping portion 212. On the other hand, the first crimping portion 211 and the second crimping portion 212 are provided diagonally on two different crimping bars 2 to play a role of binding in two different directions of the battery cell group 4, so that a good clamping and fixing effect can be provided to the battery cell group 4 by the two crimping bars 2. The cooperation between the crimping bar 2 and the end plate 1 can provide the effect of binding in each direction to the battery cell group 4.

[0042] As can be understood, by increasing the number of the crimping bars 2, the structural stability can be further improved, and a better binding effect can be provided to the battery cell group. For example, as shown in FIGS. 1 to 2, one crimping bar 2 is provided at each of the four corners of the battery cell group 4 composed of rectangular battery cells.

[0043] In some embodiments, as shown in FIG. 2, the battery module 10 further includes an adhesive layer 6, and the adhesive layer 6 is provided between the crimping bar 2 and the battery cell group 4.

[0044] That is, the crimping bar 2 and the battery cell group 4 are adhered by the adhesive layer 6 to form a sandwich structure so as to be integrated. By way of example, as shown in FIG. 2, an adhesive layer 6 is provided between the "L"-shaped crimping bar 2 and the battery cell group 4 composed of rectangular battery cells. The adhesive layer 6 adheres the crimping bar 2 and the battery cell group 4 and integrates a plurality of battery cells 3 in the battery cell group 4. The crimping bar 2 not only plays a role in stabilizing the structure in the height and width directions of the battery module 10, but also improves the structural stability in the height direction of the battery module 10.

[0045] In some embodiments, as shown in FIG. 2, the battery module 10 further includes a foam 7, and the foam 7 is located between two adjacent battery cells 3 and / or between the end plate 1 and the battery cell 3 adjacent to the end plate 1.

[0046] The foam 7 may be provided between the end plate 1 and the battery cell 3 adjacent to the end plate 1, may be provided between adjacent battery cells 3 used to form the battery cell group 4, or may be provided at the above two positions simultaneously. The foam 7 can limit the gap between the end plate 1 and the battery cell 3 and / or the gap between adjacent battery cells 3, and can serve as a buffer.

[0047] Furthermore, the foam 7 may have a hollow structure. The foam 7 with a hollow structure only covers the peripheral regions of the battery cell 3 and / or the end plate 1 so that there is a certain gap between adjacent battery cells 3 or between the end plate 1 and the battery cell 3. Thereby, the adjustment pressure when adjusting the pre-tightening force can be reduced, because the area of the foam 7 with a hollow structure is relatively small, only covering the peripheral regions of the end plate 1 and / or the battery cell 3, and the resistance generated in the process of tightening adjustment is relatively small. On the other hand, by forming cavities between the end plate 1 and the battery cell 3 and / or between adjacent battery cells 3, the overall heat dissipation performance of the lifting battery module 10 is improved, and an expansion space is secured in advance between the battery cells 3.

[0048] As an example, as shown in FIG. 2, the battery cell 3 is a rectangular battery cell, and the foam 7 correspondingly has a box structure. The foam 7 with a box structure is provided between adjacent battery cells 3 and between the end plate 1 and the battery cell 3.

[0049] As shown in FIG. 6, the embodiment of the present application provides a battery pack 100, and the battery pack 100 includes the above-mentioned battery module 10.

[0050] It should be noted that the battery pack 100 may include only one battery module 10 or may include a plurality of battery modules 10.

[0051] By applying the above-described battery module 10 to the battery pack 100, since the battery module 10 has good expansion resistance in each direction, and its structure is stable and reliable throughout the entire life cycle, the safety and reliability of the battery pack 100 are improved.

Explanation of Reference Numerals

[0052] 10: Battery module 1: End plate 11: Protrusion 2: Crimp bar 21: Crimp bar body 211: First crimping portion 212: Second crimping portion 22: Connection assembly 221: Pre-tightening member 222: Connection portion 2221: Connection hole 3: Battery cell 4: Battery cell group 6: Adhesive layer 7: Foam 100: Battery pack

Claims

1. comprising an end plate, a pressure contact bar, and battery cells, a plurality of the battery cells are arranged in sequence along a first direction to form a battery cell group, two of the end plates are respectively abutted against both ends of the battery cell group, the pressure contact bar includes a pressure contact bar body and a connection assembly, the pressure contact bar body extends along the first direction, and the connection assembly is connected to at least one end of the pressure contact bar body in the first direction, the pressure contact bar is pressed against the battery cell group, and the connection assembly is movably abutted against a side of the end plate away from the battery cell group, a battery module.

2. the connection assembly includes a pre-tightening member and a connection portion, the connection portion is connected to at least one end of the pressure contact bar body, the pre-tightening member is movably connected to the connection portion along the first direction, and an end of the pre-tightening member away from the connection portion is abutted against the end plate, the battery module according to Claim 1.

3. the end plate is further provided with a convex portion extending along the first direction, and one end of the convex portion away from the end plate is inserted into the connection portion, the battery module according to Claim 2.

4. the shape of the convex portion includes a cylindrical shape or a rectangular tube shape, the battery module according to Claim 3.

5. the connection portion is provided with a connection hole, the convex portion is inserted into a part of the connection hole, the pre-tightening member penetrates through another part of the connection hole and abuts against the convex portion, the battery module according to Claim 3 or 4.

6. the pre-tightening member is screwed into the connection hole, the battery module according to Claim 5.

7. the pressure contact bar body includes a first pressure contact portion and a second pressure contact portion, the first pressure contact portion and the second pressure contact portion respectively extend along the first direction, the second pressure contact portion is connected to one side of the first pressure contact portion, the first pressure contact portion and the second pressure contact portion are respectively pressed against adjacent both sides of the battery cell group, and both sides of the connection assembly are respectively connected to the first pressure contact portion and the second pressure contact portion, the battery module according to any one of Claims 1 to 4.

8. the connection assembly includes a connection portion, Both sides of the connection part are respectively connected to the first pressure contact part and the second pressure contact part, and the connection part, the first pressure contact part, and the second pressure contact part are perpendicular to each other. The battery module according to claim 7.

9. At least two of the pressure contact bars are provided, and at least two of the pressure contact bars are respectively located at the diagonals of the battery cell group. The battery module according to claim 7.

10. The battery module further includes an adhesive layer, and the adhesive layer is provided between the pressure contact bar and the battery cell group. The battery module according to any one of claims 1 to 4.

11. The battery cell is a rectangular battery cell, and a plurality of the battery cells are arranged in order along the thickness direction to form the battery cell group, and the two end plates are respectively abutted against both ends of the battery cell group. The battery module according to any one of claims 1 to 4.

12. The battery module further includes a foam, and the foam is located between two adjacent battery cells and / or between the end plate and the battery cell adjacent to the end plate. The battery module according to any one of claims 1 to 4.

13. The foam has a hollow structure, and the foam having the hollow structure covers the peripheral region of the battery cell and / or the end plate so that there is a gap between adjacent battery cells or between the end plate and the battery cell. The battery module according to claim 12.

14. A battery pack including the battery module according to any one of claims 1 to 4.

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