Battery module and battery pack

Abstract

A battery module (10) and a battery pack (100). The battery module (10) comprises end plates (1), pressing strips (2), and battery cells (3). A plurality of battery cells (3) are sequentially arranged in a first direction to form a battery cell group (4); two end plates (1) respectively abut against two ends of the battery cell group (4); each pressing strip (2) comprises a pressing strip main body (21) and a connecting assembly (22), the pressing strip main body (21) extends in the first direction, and the connecting assembly (22) is connected to at least one end of the pressing strip main body (21) in the first direction; and the pressing strip (2) presses against the battery cell group (4), and the connecting assembly (22) movably abuts against the side of the end plate (1) distant from the battery cell group (4).

Description

Battery module and battery pack

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 22, 2023, with application number 202323529198.6. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery module and a battery pack. Background Art

[0003] Amidst the rapid growth of the new energy vehicle market, the safety of power battery systems has been a key focus of the industry. Battery module assembly technology is a key aspect of battery pack integration design. Because battery modules are constrained by end panels or straps, their structural stability is superior to that of CTP battery packs. SUMMARY OF THE INVENTION

[0004] In related technologies, the group design method of battery modules usually adopts a thick end and side plate solution, or lightweights them, which leads to insufficient restraint on the battery cells, causing insufficient structural strength of the battery module throughout its life cycle, and then leading to irreversible expansion and deformation, or affecting the cycle life of the battery module.

[0005] The present application provides a battery module. The battery module includes an end plate, a bead, 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 abut against two ends of the battery cell group. The bead includes a bead body and a connecting assembly. The bead body extends along the first direction. The connecting assembly is connected to at least one end of the bead body in the first direction. The bead presses against the battery cell group, and the connecting assembly movably abuts against a side of the end plate away from the battery cell group.

[0006] The present application also provides a battery pack, which includes the battery module described above. Beneficial effects

[0007] The battery pack provided in the present application forms a cell group by arranging the cells in sequence along a first direction, and then forms a cell frame of the cell group by two end plates abutting at both ends of the cell group and a pressure strip connecting the two end plates, providing a restraining effect on all directions of the cell group, and the pressure strip and the end plate are movably abutted by a connecting component provided at at least one end of the pressure strip body, and the connecting component movably abuts the end plates to bring the end plates at both ends close to each other until the cell group is clamped, thereby increasing the binding force on the cell group along the first direction and further enhancing the restraining effect on the cell group in the first direction, thereby ensuring the anti-expansion ability of the battery module in all directions and ensuring that the battery module has a stable and reliable structure throughout its life cycle.

[0008] The battery pack provided in the present application, by providing the battery module described above, can ensure the anti-expansion ability of the battery pack in all directions, and ensure that the structure of the battery pack is stable and reliable throughout its entire life cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG1 is a perspective schematic diagram of a battery module provided in an embodiment of the present application;

[0010] FIG2 is an exploded view of a battery module provided in an embodiment of the present application;

[0011] FIG3 is a schematic structural diagram of a layering strip provided in an embodiment of the present application;

[0012] FIG4 is an enlarged view of point A in FIG3 ;

[0013] Figure 5 is a schematic structural diagram of the end plate provided in an embodiment of the present application;

[0014] FIG6 is a schematic structural diagram of a battery pack provided in an embodiment of the present application.

[0015] Description of reference numerals:

[0016] 10. Battery module; 1. End plate; 11. Raised structure; 2. Bead; 21. Bead body; 211. First bead portion; 212. Second bead portion; 22. Connecting assembly; 221. Preload member; 222. Connecting portion; 2221. Connecting hole; 3. Battery cell; 4. Battery cell group; 6. Adhesive layer; 7. Foam; 100. Battery pack. Modes for Carrying Out the Invention

[0017] In the description of this application, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0018] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, with the first feature having a higher horizontal height than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, with the first feature having a lower horizontal height than the second feature.

[0019] In the description of this embodiment, terms such as "upper," "lower," "left," "right," "front," and "rear" are used to refer to positions or locations based on the positions or locations shown in the accompanying drawings. These terms are intended to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and do not have any special meanings.

[0020] As shown in FIG1-2 , an embodiment of the present application provides a battery module 10 , including an end plate 1 , a pressure strip 2 , and a battery cell 3 ;

[0021] A plurality of battery cells 3 are sequentially arranged along a first direction X to form a battery cell group 4;

[0022] The two end plates 1 are respectively in contact with the two ends of the battery cell group 4;

[0023] It should be noted that the shape of the end plate 1 can match the shape of the battery cell 3. For example, when the battery cell 3 is a square battery cell, the end plate 1 is also square; and further, the size of the end plate 1 also matches the size of the battery cell 3. By setting the sizes of the end plate 1 and the battery cell 3 to match, the restraining effect of the end plate 1 on the battery cell 3 can be improved.

[0024] As shown in FIG3 , the layering strip 2 includes a layering strip body 21 and a connecting component 22 . The layering strip body 21 extends along a first direction X, and the connecting component 22 is connected to at least one end of the layering strip body 21 in the first direction X.

[0025] The holding strip 2 is pressed against the battery cell group 4 , and the connecting component 22 is movably abutted against a side of the end plate 1 away from the battery cell group 4 .

[0026] It is understandable that the connecting component 22 can be connected to only one end of the layering body 21 in the first direction X, or can be connected to both ends of the layering body 21 in the first direction X. When the connecting component 22 is connected to only one end of the layering body 21 in the first direction X, the layering body 21 at the other end can be connected to the end plate 1 by a fixed connection, and the end with the connecting component 22 can be movably abutted against the end plate 1; when the connecting component 22 is connected to both ends of the layering body 21 in the first direction X, the connecting components 22 at both ends can be movably abutted against the two end plates 1 respectively.

[0027] Exemplarily, as shown in FIG1 and FIG2 , the battery cell 3 is a square 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 in contact with both ends of the battery cell group 4 .

[0028] As shown in FIG3 , the layering strip 2 includes a layering strip body 21 and a connecting component 22 , wherein the layering strip body 21 extends along a first direction X, and the connecting component 22 is connected to at least one end of the layering strip body 21 in the first direction X. In other words, the connecting component 22 and the layering strip body 21 are integrally formed, and the two connecting components 22 are respectively connected to the two ends of the layering strip body 21 .

[0029] The pressure strip 2 is pressed against the cell group 4, and the connecting component 22 is movably abutted against the side of the end plate 1 away from the cell group 4. By buckling the pressure strip 2 on the cell group 4 and movably abutting the pressure strip 2 against the end plate 1 through the connecting component 22, the end plate 1 and the pressure strip 2 form a cell frame for constraining the cell group 4, providing a restraining effect on the cell group 4 in all directions, and the connecting component 22 provided at the end of the pressure strip body 21 movably abuts the end plate 1 to bring the end plates 1 at both ends closer to each other until the cell group 4 is clamped, thereby increasing the binding force on the cell group 4 along the first direction X, and further increasing the restraining effect of the pressure strip 2 and the end plate 1 on the cell group 4 in the first direction X, thereby ensuring the anti-expansion ability of the battery module 10 in all directions, and ensuring that the battery module 10 has a stable and reliable structure throughout its life cycle.

[0030] Preload force is one of the important design indicators for the battery module 10, and has a significant impact on the cycle life and initial stiffness of the battery module 10. However, in related technologies, the battery module 10 generally adopts a fixed preload force design, which is unable to adjust the initial preload force of the battery module 10 to match the fluctuations in the size of the incoming materials.

[0031] In some embodiments, as shown in Figure 3, the connecting assembly 22 includes a pre-tightening member 221 and a connecting portion 222; the connecting portion 222 is connected to at least one end of the pressure strip body 21, and the pre-tightening member 221 is movably connected to the connecting portion 222 along the first direction X, and the end of the pre-tightening member 221 away from the connecting portion 222 abuts against the end plate 1.

[0032] That is to say, the connecting portion 222 is connected to the pressure strip body 21, and is connected to the connecting portion 222 along the first direction X through the pre-tightening member 221, and the end of the pre-tightening member 221 facing away from the connecting portion 222 is abutted against the end plate 1, thereby realizing the connection between the pressure strip 2 and the end plate 1. At the same time, the pre-tightening member 221 realizes the flexible adjustment of the pre-tightening force of the battery module 10, thereby solving the problems of excessive or insufficient pre-tightening force that are prone to occur when the size of the incoming materials fluctuates, and avoiding the influence of excessive or insufficient pre-tightening force on the cycle life of the battery module 10.

[0033] In some embodiments, as shown in FIG5 , a protruding structure 11 extending along the first direction X is further provided on the end plate 1 , and an end of the protruding structure 11 facing away from the end plate 1 is inserted into the connecting portion.

[0034] By providing a protruding structure 11 on the end plate 1 and inserting the end of the protruding structure 11 away from the end plate 1 into the connecting portion 222, a positioning effect can be provided for the end plate 1 and the pressure strip 2, thereby better achieving the connection between the two.

[0035] It should be noted that the shape of the protruding structure 11 can be cylindrical, square column or other shapes.

[0036] Furthermore, as shown in FIG3 and FIG4 , a connecting hole 2221 is defined on the connecting portion 222 , the protruding structure 11 is inserted into a portion of the connecting hole 2221 , and the pre-tightening member 221 is passed through another portion of the connecting hole 2221 and abuts against the protruding structure 11 .

[0037] On the one hand, the protruding structure 11 inserted into the connecting hole 2221 plays a positioning role. On the other hand, the preload member 221 and the protruding structure 11 abut against each other in the connecting hole 2221, thereby realizing the connection between the end plate 1 and the pressure strip 2, and the structure is more compact.

[0038] Furthermore, when the cell pack 4 expands, it exerts outward expansion pressure on the beading 2 distributed around the cell pack 4, thereby increasing the radial force on the preload member 221, which in turn affects the preload adjustment and removal of the preload member 221. The protruding structure 11 provided on the end plate 1 not only serves as a positioning function but also enhances the radial limiting function. This can reduce the radial force on the preload member 221 during non-uniform deformation of the battery module 10 when the cell pack 4 expands and deforms, thereby reducing the impact of the cell pack 4 expansion.

[0039] In some embodiments, the pre-tightening member 221 is threadedly connected to the connecting hole 2221 .

[0040] The pre-tightening member 221 is threadedly connected to the connecting hole 2221, and the pre-tightening member 221 is connected to the pressure strip 2 and pressurizes the end plate 1 to achieve the connection between the pressure strip 2 and the end plate 1. At the same time, the connecting hole 2221 cooperates with the protruding structure 11 to achieve a positioning effect. The pre-tightening member 221 is connected to the connecting hole 2221 by a threaded connection, which facilitates flexible adjustment of the pre-tightening force.

[0041] Illustratively, the pre-tightening member 221 may be a tightening adjustment bolt, and the connecting hole 2221 may be a threaded hole.

[0042] In some embodiments, as shown in Figure 3, the pressure strip body 21 includes a first pressure strip portion 211 and a second pressure strip portion 212. The first pressure strip portion 211 and the second pressure strip portion 212 extend along the first direction X respectively. The second pressure strip portion 212 is connected to one side of the first pressure strip portion 211. The first pressure strip portion 211 and the second pressure strip portion 212 respectively press against the adjacent two sides of the battery cell group. The two sides of the connecting component 22 are respectively connected to the first pressure strip portion 211 and the second pressure strip portion 212.

[0043] The first pressure strip portion 211 and the second pressure strip portion 212 are respectively pressed against the adjacent two sides of the battery cell group 4. The first pressure strip portion 211 and the second pressure strip portion 212 can respectively provide constraints on the battery cell group 4 in different directions, while improving the structural strength in two directions. Through the mutual cooperation of multiple pressure strips 2, the battery cell group 4 can form a more stable whole, and the overall rigidity of the battery module 10 can be significantly improved.

[0044] Furthermore, the connecting assembly 22 includes a connecting portion 222 ; both sides of the connecting portion 222 are respectively connected to the first beading portion 211 and the second beading portion 212 , and the connecting portion 222 , the first beading portion 211 and the second beading portion 212 are perpendicular to each other.

[0045] For example, as shown in FIG3 , the first beading portion 211 and the second beading portion 212 are perpendicular to each other, that is, the beading body 21 has an "L"-shaped structure, and the connecting portion 222 is perpendicular to the first beading portion 211 and the second beading portion 212, respectively. For the battery cell group 4 composed of square battery cells, the mutually perpendicular first beading portion 211 and second beading portion 212 can improve the structural strength in two directions. At the same time, the mutually perpendicular first beading portion 211, second beading portion 212 and connecting portion 222 can position and limit the end plate 1 in three directions, thereby improving the structural stability of the battery module 10.

[0046] It should be noted that the widths of the first pressure strip portion 211 and the second pressure strip portion 212 can be the same or different; in actual application, the widths and relative positions of the first pressure strip portion 211 and the second pressure strip portion 212 can be adjusted according to the size of the constraint effect provided in different directions as needed.

[0047] In some embodiments, at least two holding strips 2 are provided, and the at least two holding strips 2 are respectively located at diagonally opposite corners of the battery cell group 4 .

[0048] Since the pressure strip 2 includes the first pressure strip portion 211 and the second pressure strip portion 212, and the first pressure strip portion 211 and the second pressure strip portion 212 can provide constraints on the battery cell group 4 in two different directions, the two pressure strips 2 arranged diagonally can provide good clamping and fixing effects on the battery cell group 4. The pressure strip 2 and the end plate 1 can cooperate to provide constraints in all directions for the battery cell group 4.

[0049] It is understandable that by increasing the number of beadings 2, the stability of the structure can be further improved, providing a better restraint effect for the cell group. For example, as shown in Figures 1-2, a beading 2 is provided at each of the four corners of the cell group 4 composed of square cells.

[0050] In some embodiments, as shown in FIG. 2 , the battery module 10 further includes an adhesive layer 6 , which is disposed between the pressure strip 2 and the battery cell group 4 .

[0051] That is to say, the bead 2 and the battery cell group 4 are bonded together by the adhesive layer 6 to form a sandwich structure, so that the bead 2 and the battery cell group 4 form a whole; for example, as shown in Figure 2, an adhesive layer 6 is provided between the "L"-shaped bead 2 and the battery cell group 4 composed of square batteries. The adhesive layer 6 bonds the bead 2 and the battery cell group 4 together, and at the same time forms a plurality of battery cells 3 in the battery cell group 4 into a whole. The bead 2 not only plays a role in structural stability in the height and width directions of the battery module 10, but also improves the structural stability of the battery module 10 in the length direction.

[0052] In some embodiments, as shown in FIG. 2 , the battery module 10 further includes a foam 7 , which 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 .

[0053] The foam 7 can be disposed between the end plate 1 and the battery cells 3 adjacent to the end plate 1, or between adjacent battery cells 3 forming a battery cell group 4, or in both locations. The foam 7 can limit the gap between the end plate 1 and the battery cells 3 and / or between adjacent battery cells 3, and provide a cushioning effect.

[0054] Furthermore, the foam 7 can be a hollow structure, and the foam 7 with a hollow structure only covers the circumferential edge 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. On the one hand, it can reduce the adjustment pressure when adjusting the preload force. This is mainly because the foam 7 with a hollow structure has a smaller area and only covers the circumferential edge of the end plate 1 and / or the battery cell 3, so the resistance generated during the tightening adjustment process is smaller; on the other hand, a cavity is formed between the end plate 1 and the battery cell 3, and / or between adjacent battery cells 3, thereby improving the overall heat dissipation capacity of the battery module 10 and also reserving expansion space between the battery cells 3.

[0055] Exemplarily, as shown in FIG2 , the battery cell 3 is a square battery cell, and the foam 7 has a corresponding square frame structure. The foam 7 with the square frame structure is simultaneously arranged between adjacent battery cells 3 and between the end plate 1 and the battery cell 3 .

[0056] As shown in FIG6 , an embodiment of the present application provides a battery pack 100 including the battery module 10 as described above.

[0057] It should be noted that the battery pack 100 may include only one battery module 10 or may include multiple battery modules 10 at the same time.

[0058] By applying the above-mentioned battery module 10 to the battery pack 100 , the safety and reliability of the battery pack 100 are improved because the battery module 10 has good anti-expansion capability in all directions and a stable and reliable structure throughout its entire life cycle.

Claims

1. A battery module, comprising an end plate, a pressure strip and a battery cell; The plurality of battery cells are arranged in sequence along a first direction to form a battery cell group; The two end plates are respectively abutted against two ends of the battery cell group; The pressure strip comprises a pressure strip body and a connecting assembly, wherein the pressure strip body extends along the first direction, and the connecting assembly is connected to at least one end of the pressure strip body in the first direction; The pressure strip is pressed against the battery cell group, and the connecting component is movably abutted against a side of the end plate away from the battery cell group.

2. The battery module according to claim 1, wherein: The connecting assembly includes a pre-tightening member and a connecting portion; The connecting portion is connected to at least one end of the pressure strip body, the pre-tightening member is movably connected to the connecting portion along the first direction, and the end of the pre-tightening member away from the connecting portion abuts against the end plate.

3. The battery module according to claim 2, wherein: The end plate is also provided with a protruding structure extending along the first direction, and one end of the protruding structure away from the end plate is inserted into the connecting portion.

4. The battery cell module according to claim 3, wherein: The shape of the protruding structure includes a cylindrical shape or a square cylindrical shape.

5. The battery module according to claim 3 or 4, wherein: The connecting portion is provided with a connecting hole, the protruding structure is inserted into a part of the connecting hole, and the pre-tightening member is inserted into another part of the connecting hole and abuts against the protruding structure.

6. The battery module according to claim 5, wherein: The preload member is threadedly connected to the connection hole.

7. The battery module according to any one of claims 1 to 6, wherein: The pressure strip body includes a first pressure strip portion and a second pressure strip portion, the first pressure strip portion and the second pressure strip portion extend along the first direction respectively, the second pressure strip portion is connected to one side of the first pressure strip portion, the first pressure strip portion and the second pressure strip portion respectively press against two adjacent sides of the battery cell group, and the two sides of the connecting component are respectively connected to the first pressure strip portion and the second pressure strip portion.

8. The battery module according to claim 7, wherein: The connecting assembly includes a connecting portion; The two sides of the connection portion are respectively connected to the first pressure strip portion and the second pressure strip portion, and the connection portion, the first pressure strip portion and the second pressure strip portion are perpendicular to each other.

9. The battery module according to claim 7 or 8, wherein: The number of the pressure strips is at least two, and the at least two pressure strips are respectively located at diagonally opposite corners of the battery cell group. 10 . The battery module according to claim 1 , further comprising an adhesive layer, wherein the adhesive layer is disposed between the pressure strip and the battery cell group.

11. The battery module according to any one of claims 1 to 10, wherein: The battery core is a square battery core, and a plurality of the battery cores are arranged in sequence along the thickness direction to form the battery core group, and the two end plates are respectively abutted against two ends of the battery core group.

12. The battery module according to any one of claims 1 to 10, further comprising foam, wherein the foam is located between two adjacent battery cells and / or between the end plate and the battery cell adjacent to the end plate.

13. The battery module according to claim 12, wherein: The foam is a hollow structure, and the foam with the hollow structure covers the circumferential edge of the battery core and / or the end plate, so that there is a certain gap between adjacent battery cores or between the end plate and the battery core.

14. A battery pack comprising the battery module according to any one of claims 1 to 13.

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