Battery module and battery pack

Abstract

The present application provides a battery module and a battery pack, wherein the battery module comprises an end plate, a pressure strip, and a battery cell; a plurality of battery cells are arranged sequentially along a first direction to form a battery cell group; two end plates are each in contact with both 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 a 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 assembly is movably in contact with one side of the end plate away from the battery cell group.

Description

Technology Field

[0001] The present application claims priority to the Chinese patent application No. 202323529198.6, filed with the Chinese Intellectual Property Office on December 22, 2023, the entire contents of said application are incorporated by reference into the present application.

[0002] This application relates to the field of battery technology, specifically to battery modules and battery packs. Background Technology

[0003] With the new energy vehicle market developing rapidly, the safety of power battery systems has always been a focal point of industry interest. Battery module assembly technology is a key direction in the integrated design of battery packs, and because battery modules are secured by end-side plates or straps, their structural stability is superior to that of CTP battery packs. means of solving the problem

[0004] In related technologies, the assembly design of battery modules generally adopts thick and heavy end-side plates or attempts to lighten them, but this results in insufficient restraint on the battery cells. Consequently, the structural strength of the battery module over its entire lifecycle is insufficient, 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 comprises an end plate, a pressure strip, and a battery cell; a plurality of battery cells are arranged sequentially along a first direction to form a battery cell group; two end plates are each in contact with both ends of the battery cell group; the pressure strip comprises a pressure strip body and a connecting assembly, the pressure strip body extends along a 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 assembly is movably in contact with one side of the end plate away from the battery cell group.

[0006] The present application further provides a battery pack. The battery pack includes the battery module mentioned above. Effects of the invention

[0007] The battery pack provided in the present application forms a battery cell group by sequentially arranging battery cells along a first direction, and then forms a battery cell frame of the battery cell group through two end plates in contact with the battery cell group and a pressure strip connecting the two end plates, thereby providing a restraining effect in each direction of the battery cell group, and the pressure strip and the end plates are movably in contact through a connecting assembly installed at least one end of the pressure strip body, and the connecting assembly is movably in contact with the end plates so that the end plates at both ends are close to each other until they clamp the battery cell group, thereby increasing the restraining force of the battery cell group along the first direction and further enhancing the restraining effect in the first direction of the battery cell group, thereby ensuring the ability to prevent expansion of the battery module in each direction and ensuring that the structure of the battery module is stable and reliable throughout the entire life cycle.

[0008] The battery pack provided in this application, by installing the aforementioned battery module, can ensure the ability to prevent expansion of the battery pack in each direction and ensure that the structure of the battery pack remains stable and reliable throughout its entire life cycle. Brief explanation of the drawing

[0009] FIG. 1 is a schematic perspective view of a battery module provided in an embodiment of the present application. FIG. 2 is an exploded view of a battery module provided in an embodiment of the present application. FIG. 3 is a schematic diagram of the structure of a pressure strip provided in an embodiment of the present application. Figure 4 is an enlarged view of position A in Figure 3. FIG. 5 is a schematic diagram of the structure of an end plate provided in an embodiment of the present application. FIG. 6 is a schematic diagram of the structure of a battery pack provided in an embodiment of the present application. Explanation of the symbols: 10: Battery module; 1: End plate; 11: Protrusion structure; 2: Pressure strip; 21: Pressure strip body; 211: First pressure strip section; 212: Second pressure strip section; 22: Connection assembly; 221: Pretensioner; 222: Connection section; 2221: Connection hole; 3: Battery cell; 4: Battery cell group; 6: Adhesive layer; 7: Foam; 100: Battery pack. Specific details for implementing the invention

[0010] In the description of this application, the terms “interconnected,” “connected,” and “fixed” should be understood in a broad sense unless otherwise specified. For example, they may be fixed connections or detachable connections, or integral; they may be mechanical connections or electrical connections. They may be directly connected to each other or indirectly connected to each other through an intermediate medium, and may be communication within two elements or an interaction relationship between two elements. A person skilled in the art will understand the specific meanings of the above terms in this application according to the specific circumstances.

[0011] Unless otherwise specified in this application, the first feature being "above" or "below" the second feature may include direct contact between the first feature and the second feature, or may include contact through additional features between them that are not direct contact between the first feature and the second feature. Additionally, the first feature being "above," "upward," or "above" the second feature includes the first feature being located at the top and bottom of the second feature, and the horizontal height of the first feature is higher than that of the second feature. The first feature being "below," "downward," or "below" the second feature includes the first feature being located at the bottom and bottom of the second feature, and the horizontal height of the first feature is lower than that of the second feature.

[0012] In the description of the embodiments, orientations or positional relationships such as “up,” “down,” “left,” “right,” “front,” and “back” are based on the orientations or positional relationships illustrated in the accompanying drawings. These are merely for convenience to simply explain the embodiments of the present application and do not imply or suggest that the device or element indicated necessarily has a specific orientation or is structured and operated in a specific orientation; therefore, this should not be understood as a limitation on the embodiments of the present application. Furthermore, the terms “first” and “second” are used for distinction in the description and have no special meaning.

[0013] As illustrated in FIG. 1-2, an embodiment of the present application provides a battery module (10) comprising an end plate (1), a pressure strip (2), and a battery cell (3).

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

[0015] Two end plates (1) are each attached to both ends of the battery cell group (4).

[0016] It needs to be explained that the shape of the end plate (1) can be matched to the shape of the battery cell (3), for example, if the battery cell (3) is a rectangular battery cell, the end plate (1) is also rectangular; furthermore, the size of the end plate (1) is also matched to the size of the battery cell (3), and by installing the end plate (1) and the battery cell (3) so that their sizes match, the restraining effect of the end plate (1) on the battery cell (3) can be improved.

[0017] As illustrated in FIG. 3, the pressure strip (2) comprises a pressure strip body (21) and a connecting assembly (22), the pressure strip body (21) extends along a first direction (X), and the connecting assembly (22) is connected to at least one end of the pressure strip body (21) in the first direction (X);

[0018] The pressure strip (2) is pressed against the battery cell group (4), and the connecting assembly (22) is movably connected to one side of the end plate (1) away from the battery cell group (4).

[0019] It can be understood that the connecting assembly (22) may be connected only to one end of the pressure strip body (21) in the first direction (X), or may be connected simultaneously to both ends of the pressure strip body (21) in the first direction (X). When the connecting assembly (22) is connected only to one end of the pressure strip body (21) in the first direction (X), the pressure strip body (21) at the other end may be connected to the end plate (1) via a fixed connection method, and the end having the connecting assembly (22) is movably in contact with the end plate (1); when the connecting assembly (22) is connected simultaneously to both ends of the pressure strip body (21) in the first direction (X), the connecting assembly (22) located at both ends is movably connected to each of the two end plates (1).

[0020] For example, as illustrated in FIGS. 1 and 2, the battery cell (3) is a rectangular battery cell, and a plurality of battery cells (3) are arranged sequentially along the thickness direction to form a battery cell group (4), and two end plates (1) are each in contact with both ends of the battery cell group (4).

[0021] As illustrated in FIG. 3, the pressure strip (2) comprises a pressure strip body (21) and a connecting assembly (22), wherein the pressure strip body (21) extends along a first direction (X), and the connecting assembly (22) is connected to at least one end of the pressure strip body (21) in the first direction (X). That is, the connecting assembly (22) and the pressure strip body (21) are integral, and the two connecting assemblies (22) are each connected to two ends of the pressure strip body (21).

[0022] The pressure strip (2) is pressed against the battery cell group (4), and the connecting assembly (22) is movably connected to one side of the end plate (1) away from the battery cell group (4). A pressure strip (2) is placed over a battery cell group (4), and the pressure strip (2) is movably connected to an end plate (1) through a connecting assembly (22), so that the end plate (1) and the pressure strip (2) form a battery cell frame for restraining the battery cell group (4), thereby providing a restraining effect in each direction of the battery cell group (4). The connecting assembly (22) installed at the end of the pressure strip body (21) is movably connected to the end plate (1) so that the end plates (1) at both ends are close to each other until they clamp the battery cell group (4), thereby increasing the restraining force of the battery cell group (4) along the first direction (X) and further enhancing the restraining effect of the pressure strip (2) and the end plate (1) on the battery cell group (4) in the first direction (X), thereby ensuring the ability to prevent expansion of the battery module (10) in each direction and ensuring that the structure of the battery module (10) remains stable and reliable throughout its entire life cycle.

[0023] Preload is one of the important indicators in the design of the battery module (10) and has a significant impact on the cycle life and initial rigidity of the battery module (10). However, in the relevant technology, the battery module (10) generally adopts a design method of fixed preload, and the initial preload of the battery module (10) cannot be adjusted to match the material size variation.

[0024] In some embodiments, as illustrated in FIG. 3, the connection assembly (22) includes a pretensioner (221) and a connection part (222); the connection part (222) is connected to at least one end of the pressure strip body (21), and the pretensioner (221) is movably connected to the connection part (222) along a first direction (X), and the end of the pretensioner (221) away from the connection part (222) is in contact with the end plate (1).

[0025] That is, the connecting portion (222) is connected to the pressure strip body (21) and connected to the connecting portion (222) according to the first direction (X) through the pretensioner (221), and the end of the pretensioner (221) moving away from the connecting portion (222) is brought into contact with the end plate (1), thereby realizing the connection between the pressure strip (2) and the end plate (1) and simultaneously realizing flexible control of the prepressure of the battery module (10) through the pretensioner (221), thereby solving problems such as exceeding or falling short of the standard prepressure that easily occur when the material size changes, and at the same time preventing the cycle life from being affected by exceeding or falling short of the standard prepressure of the battery module (10).

[0026] In some embodiments, as shown in FIG. 5, a projection structure (11) extending along a first direction (X) is further installed on the end plate (1), and one end of the projection structure (11) extending away from the end plate (1) is inserted into a connection part.

[0027] A protrusion structure (11) is installed on the end plate (1), and one end of the protrusion structure (11) extending away from the end plate (1) is inserted into the connecting part (222), thereby providing a positioning function to the end plate (1) and the pressure strip (2), so that the connection between the two can be better implemented.

[0028] What needs to be explained is that the shape of the protrusion structure (11) can be cylindrical, rectangular, or other shapes.

[0029] Furthermore, as shown in FIGS. 3 and 4, a connecting hole (2221) is opened in the connecting portion (222), a projection structure (11) is inserted into a part of the connecting hole (2221), and a pretensioner (221) penetrates another part of the connecting hole (2221) and comes into contact with the projection structure (11).

[0030] Meanwhile, the protrusion structure (11) is inserted into the connection hole (2221) to serve as a positioning element, while the pretensioner (221) and the protrusion structure (11) come into contact within the connection hole (2221) to implement the connection between the end plate (1) and the pressure strip (2), making the structure more compact.

[0031] Additionally, when the battery cell group (4) expands, an outward expansion pressure is generated in the pressure strip (2) distributed around the battery cell group (4), thereby increasing the radial force of the pretensioner (221) and affecting the preload control and release of the pretensioner (221). However, the protrusion structure (11) installed on the end plate (1) not only serves as a positioning mechanism but can also enhance the radial limiting effect. Furthermore, when the battery cell group (4) expands and deforms, the radial force of the pretensioner (221) can be reduced when the battery module (10) deforms unevenly, thereby reducing the impact of the expansion of the battery cell group (4).

[0032] In some embodiments, the pretensioner (221) is screw-coupled to the connecting hole (2221).

[0033] Through the screw connection between the pretensioner (221) and the connection hole (2221), the pretensioner (221) is connected to the pressure strip (2) and pressurizes the end plate (1), thereby realizing the connection between the pressure strip (2) and the end plate (1), while the connection hole (2221) is combined with the protrusion structure (11) to realize a positioning effect, and the pretensioner (221) is connected to the connection hole (2221) through a screw connection method, which facilitates flexible adjustment of the pre-pressure.

[0034] For example, the pretensioner (221) may be a fastening adjustment bolt, and the connecting hole (2221) may be a screw hole.

[0035] In some embodiments, as illustrated in FIG. 3, the pressure strip body (21) comprises 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) each extend along a first direction (X), 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) each press adjacent sides of a battery cell group, and both sides of the connecting assembly (22) are connected to the first pressure strip portion (211) and the second pressure strip portion (212), respectively.

[0036] The first pressure strip (211) and the second pressure strip (212) are respectively in contact with adjacent sides of the battery cell group (4), and the first pressure strip (211) and the second pressure strip (212) can each provide a restraining effect in different directions of the battery cell group (4) while simultaneously improving structural strength in two directions, and through the mutual coupling of the plurality of pressure strips (2), the battery cell group (4) can be formed as a more stable integral, and the overall rigidity of the battery module (10) can be greatly improved.

[0037] Furthermore, the connecting assembly (22) includes a connecting portion (222); both sides of the connecting portion (222) are connected to a first pressure strip portion (211) and a second pressure strip portion (212), respectively, and the connecting portion (222), the first pressure strip portion (211), and the second pressure strip portion (212) are vertically connected in pairs.

[0038] For example, as illustrated in FIG. 3, the first pressure strip section (211) and the second pressure strip section (212) are perpendicular to each other, that is, the pressure strip body (21) has an “L”-shaped structure, and the connecting section (222) is perpendicular to the first pressure strip section (211) and the second pressure strip section (212), respectively. In the case of a battery cell group (4) composed of rectangular battery cells, the first pressure strip section (211) and the second pressure strip section (212) perpendicular to each other can improve structural strength in two directions, and at the same time, the first pressure strip section (211), the second pressure strip section (212), and the connecting section (222) perpendicular to each other serve as positioning and position limiting in three directions of the end plate (1) to improve the structural stability of the battery module (10).

[0039] It should be explained that the widths of the first pressure strip (211) and the second pressure strip (212) may be the same or different; and in the actual application process, the widths and relative positions of the first pressure strip (211) and the second pressure strip (212) may be adjusted according to the magnitude of the restraint effect provided in different directions depending on the demand.

[0040] In some embodiments, the pressure strips (2) are installed in at least two places, and at least two pressure strips (2) are each located diagonally across the battery cell group (4).

[0041] The pressure strip (2) simultaneously includes a first pressure strip section (211) and a second pressure strip section (212), and since the first pressure strip section (211) and the second pressure strip section (212) can provide a restraining effect in two different directions of the battery cell group (4), good clamping and fixing effects can be provided to the battery cell group (4) through two pressure strips (2) installed diagonally, and the combination of the pressure strip (2) and the end plate (1) can provide a restraining effect in each direction to the battery cell group (4).

[0042] It can be understood that by increasing the number of pressure strips (2), structural stability can be further improved and a better restraining effect can be provided to the battery cell group. For example, as shown in FIG. 1-2, one pressure strip (2) is installed at each of the four corners of a 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) installed between the pressure strip (2) and the battery cell group (4).

[0044] That is, the pressure strip (2) and the battery cell group (4) are bonded together through an adhesive layer (6) to form a sandwich structure, so that the pressure strip (2) and the battery cell group (4) are formed integrally; for example, as shown in FIG. 2, an adhesive layer (6) is installed between an “L”-shaped pressure strip (2) and a battery cell group (4) composed of rectangular battery cells, and the adhesive layer (6) bonds the pressure strip (2) and the battery cell group (4) together, and at the same time, a plurality of battery cells (3) of the battery cell group (4) are formed integrally, so that the pressure strip (2) not only serves as a structural stability in the height and width directions of the battery module (10), but also improves the structural stability in the length direction of the battery module (10).

[0045] In some embodiments, as shown in FIG. 2, the battery module (10) further includes a form (7) 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 installed between the end plate (1) and the battery cell (3) adjacent to the end plate (1), may be installed between adjacent battery cells (3) to form a battery cell group (4), or may be installed simultaneously at both locations. The foam (7) may limit the gap between the end plate (1) and the battery cell (3), and / or between adjacent battery cells (3), and provide a buffering effect.

[0047] Furthermore, the foam (7) may be a hollow structure, and the hollow foam (7) covers only the periphery-direction position of the battery cell (3) and / or end plate (1), thereby creating a constant gap between adjacent battery cells (3) or between the end plate (1) and the battery cell (3), and on the one hand, the control pressure when controlling the pre-pressure can be reduced, mainly because the area of ​​the hollow foam (7) is small and it covers only the periphery-direction area of ​​the end plate (1) and / or battery cell (3), so the resistance generated during the fastening control process is small; 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 leaving an expansion space between the battery cells (3).

[0048] For example, as illustrated in FIG. 2, the battery cell (3) is a rectangular battery cell, and the foam (7) corresponds to a rectangular frame structure, and the foam (7) of the rectangular frame structure is installed simultaneously between adjacent battery cells (3) and between the end plate (1) and the battery cell (3).

[0049] As illustrated in FIG. 6, an embodiment of the present application provides a battery pack (100) comprising the battery module (10) mentioned above.

[0050] It should be explained that the battery pack (100) may include only one battery module (10) or may include multiple battery modules (10) simultaneously.

[0051] By applying the above battery module (10) to the battery pack (100), the battery module (10) has good anti-inflation ability in each direction, and the structure is stable and reliable throughout the entire life cycle, thereby improving the safety and reliability of the battery pack (100).

Claims

Claim 1 A battery module comprising an end plate, a pressure strip, and a battery cell, wherein a plurality of the battery cells are sequentially arranged along a first direction to form a battery cell group; two of the end plates are each in contact with both 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 assembly is movably in contact with one side of the end plate away from the battery cell group, wherein the connecting assembly comprises a pretensioner and a connecting portion, wherein the connecting portion is connected to at least one end of the pressure strip body and the pretensioner is movably connected to the connecting portion along the first direction, wherein the end of the pretensioner away from the connecting portion is in contact with the end plate, wherein a projection structure extending along the first direction is further installed on the end plate and the end of the projection structure away from the end plate is inserted into the connecting portion. Claim 2 delete Claim 3 delete Claim 4 A battery module according to claim 1, wherein the shape of the protrusion structure includes a cylindrical or rectangular prism shape. Claim 5 A battery module according to claim 1 or 4, wherein the connecting portion has a connecting hole opened, the projection structure is inserted into a part of the connecting hole, and the pretensioner penetrates another part of the connecting hole and contacts the projection structure. Claim 6 In paragraph 5, the battery module, wherein the pretensioner is screw-coupled to the connection hole. Claim 7 A battery module according to claim 1 or 4, wherein the pressure strip body comprises a first pressure strip portion and a second pressure strip portion, wherein the first pressure strip portion and the second pressure strip portion each extend along the first direction, and the second pressure strip portion is connected to one side of the first pressure strip portion, and the first pressure strip portion and the second pressure strip portion each compress adjacent sides of the battery cell group, and both sides of the connecting assembly are connected to the first pressure strip portion and the second pressure strip portion, respectively. Claim 8 A battery module according to claim 7, wherein both sides of the connecting portion are respectively connected to the first pressure strip portion and the second pressure strip portion, and the connecting portion, the first pressure strip portion, and the second pressure strip portion are vertically arranged in pairs. Claim 9 A battery module according to claim 7, wherein the pressure strips are installed in at least two places, and at least two pressure strips are each located on the diagonal of the battery cell group. Claim 10 A battery module according to claim 1 or 4, wherein the battery module further comprises an adhesive layer installed between the pressure strip and the battery cell group. Claim 11 A battery module according to claim 1 or 4, wherein the battery cell is a rectangular battery cell, a plurality of the battery cells are arranged sequentially along the thickness direction to form the battery cell group, and two end plates are respectively attached to both ends of the battery cell group. Claim 12 A battery module according to claim 1 or 4, wherein the battery module further comprises a form located between two adjacent battery cells and / or between the end plate and the battery cell adjacent to the end plate. Claim 13 A battery module according to claim 12, wherein the foam is a hollow structure, and the foam of the hollow structure covers the periphery position of the edge of the battery cell and / or the end plate to have a constant gap between adjacent battery cells or between the end plate and the battery cell. Claim 14 A battery pack comprising a battery module according to paragraph 1 or 4.

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