Battery pack

Abstract

A battery pack, comprising a battery cell group (11), a holder (12) and a side plate (2); the holder (12) is arranged close to the bottom wall of the battery cell group (11) and is connected to the side portion of the battery cell group (11); the side plate (2) comprises a first plate part (21), a second plate part (22) and a connecting part (25), the connecting part (25) connecting the first plate part (21) and the second plate part (22); the first plate part (21) is connected to the side portion of the battery cell group (11) and does not interfere with the holder (12); the second plate part (22) is connected to the side of the holder (12) away from the battery cell group (11); the distance between the first plate part (21) and the side portion of the battery cell group (11) is less than the distance between the second plate part (22) and the side portion of the battery cell group (11). The present application improves the heat exchange efficiency at the first plate part (21), and fully utilizes the space of the side plate (2), thus ensuring the heat exchange consistency of battery packs, and improving the heat dissipation performance of battery packs.

Description

A battery pack

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on September 7, 2023, with application number 202311157399.X and application name “A Battery Pack”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of power batteries, and specifically to a battery pack. Background Art

[0003] At present, new energy vehicles are a key development project of the country. They have the advantages of low emissions, high energy utilization, and low noise. As the power source of new energy vehicles, battery cells are also a project vigorously promoted by the country. However, compared with traditional engines, battery cells have a considerable gap in power and range. Among them, the unreasonable structure of the battery cells is an important cause of this problem. In the existing technology, the structure of the battery cells is a regular square, and the side panels are glued to the module body by glue. Such a structure has poor installation stability. Although the use of brackets to install the battery cells can improve the installation stability, this will result in a certain space between the upper part of the side panel and the battery cells, making the distance between the battery cells and the cooling device outside the side panel farther, resulting in poor heat dissipation effect and heat dissipation consistency of the battery cells, making it difficult to meet the use requirements. Therefore, an improved solution is urgently needed to solve the above problems.

[0004] Summary of the Invention

[0005] The technical problem to be solved by this application is: how to improve the heat exchange efficiency of battery cells.

[0006] In order to solve the above technical problems, the present application provides a battery pack, comprising:

[0007] A battery cell group, the battery cell group having a second direction, the battery cell group comprising a plurality of battery cells, the plurality of battery cells being arranged along the second direction, and side walls of the plurality of battery cells forming a side portion of the battery cell group along the second direction;

[0008] A bracket, wherein the bracket is provided with a plurality of limiting grooves arranged at intervals along the second direction, each of the plurality of battery cells is correspondingly inserted into each of the plurality of limiting grooves, each of the plurality of limiting grooves has a groove wall, and the bottom wall and the side wall of each of the plurality of battery cells are connected to the groove wall;

[0009] A side plate is arranged on the side of the battery cell group, and the side plate includes a first plate portion, a second plate portion and a connecting portion, and the connecting portion is connected to the first plate portion and the second plate portion; the first plate portion is connected to the side walls of the multiple battery cells, and the second plate portion is connected to the side of the bracket away from the battery cell group.

[0010] In some embodiments of the present application, the distance L1 between the first plate portion and the side of the battery cell group and the distance L2 between the second plate portion and the side of the battery cell group satisfy: 0.1mm≤L2-L1≤5mm, or 1mm≤L2-L1≤2mm.

[0011] In some embodiments of the present application, a distance L1 between the first plate portion and the side of the battery cell group and a distance L2 between the second plate portion and the side of the battery cell group satisfy: 0≤L1≤3mm, 0.1mm≤L2≤5mm.

[0012] In some embodiments of the present application, the dimension of the second plate portion along the height direction of the battery cell group is H1 mm, and the dimension of the bracket along the height direction of the battery cell group is H2, satisfying: H1≥H2, and 0≤H1-H2≤10mm.

[0013] In some embodiments of the present application, the side panel further includes an upper limit portion and a lower limit portion, the upper limit portion is arranged along one end of the first plate portion away from the second plate portion, and abuts against the top wall of the battery cell group, and the lower limit portion is arranged along one end of the second plate portion away from the first plate portion, and abuts against the bottom wall of the bracket.

[0014] In some embodiments of the present application, the dimension of the upper limit portion extending from the first plate portion is W1, and the dimension of the lower limit portion extending from the second plate portion is W2, satisfying: W2 ≥ W1.

[0015] In some embodiments of the present application, the first plate portion, the second plate portion, and the connecting portion are integrally formed.

[0016] In some embodiments of the present application, the connecting portion is a broken line transition section or an arc transition section.

[0017] In some embodiments of the present application, the invention further comprises: a first heat-conducting structural adhesive layer, a second heat-conducting structural adhesive layer;

[0018] The first heat-conducting structural adhesive layer is connected to the first plate portion and the battery core group, and the second heat-conducting structural adhesive layer is connected to the second plate portion and the bracket.

[0019] In some embodiments of the present application, further comprising:

[0020] A liquid cooling plate and a third heat-conducting structural adhesive layer, wherein the liquid cooling plate is connected to a side of the first plate portion facing away from the battery cell group through the third heat-conducting structural adhesive layer.

[0021] Compared with the prior art, the battery pack of the embodiment of the present application has the following advantages:

[0022] The battery pack of the present application is provided with a cell group and a bracket. The cell group can provide power for electrical equipment. The cell group is installed on the bracket, which can effectively reduce the difficulty of assembly and increase the installation stability of the battery. At the same time, side panels are installed on the sides of the cell group, and the side panels have a stepped structure. The first plate portion is arranged close to the cell group, thereby reducing the distance between the first plate portion and the cell group, and thus making the external cooling system closer to the cell group at the first plate portion, thereby improving the heat exchange efficiency at the first plate portion, making full use of the space of the side panel, ensuring the consistency of heat exchange of the battery pack, and improving the heat dissipation performance of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a perspective view of the battery pack of the present application;

[0024] FIG2 is an exploded view of the battery pack of the present application;

[0025] FIG3 is a side view of the arc transition section side plate of the present application;

[0026] FIG4 is a side view of the side panel of the broken line transition section of the present application;

[0027] FIG5 is a perspective view of the bracket of the present application;

[0028] FIG6 is a schematic diagram of the internal structure of the present application after removing the battery cell group;

[0029] FIG7 is a schematic diagram of the liquid cooling plate installation structure of the present application.

[0030] In the figure, 11, battery cell group; 111, battery cell; 12, bracket; 121, limiting groove; 1211, rubber blocking protrusion; 122, enclosure; 1221, accommodating cavity; 123, partition; 2, side plate; 21, first plate portion; 22, second plate portion; 23, upper limiting portion; 24, lower limiting portion; 25, connecting portion; 3, first thermal conductive structural adhesive layer; 4, second thermal conductive structural adhesive layer; 5, liquid cooling plate; 6, third thermal conductive structural adhesive layer; 7, end plate; 8, module cover;

[0031] X, first direction; Y, second direction; L1, distance between the first plate portion and the side of the battery cell group; L2, distance between the second plate portion and the side of the battery cell group; H1, dimension of the second plate portion along the height direction of the battery cell group; H2, dimension of the bracket along the height direction of the battery cell group; W1, dimension of the upper limit portion extending from the first plate portion; W2, dimension of the lower limit portion extending from the second plate portion. DETAILED DESCRIPTION

[0032] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0033] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", etc. used in this application to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0034] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0035] As shown in Figures 1-7, the present application proposes a battery pack, including: a battery cell group 11, a bracket 12 and a side plate 2, the battery cell group 11 has a second direction Y, the battery cell group 11 includes multiple battery cells, the multiple battery cells are arranged along the second direction Y, and the side walls of the multiple battery cells form the side of the battery cell group 11 along the second direction Y; the bracket 12 is provided with multiple limiting grooves 121 arranged at intervals along the second direction Y, and each battery cell is correspondingly inserted into each limiting groove 121, each limiting groove 121 has a groove wall, and the bottom wall and side wall of each battery cell are connected to each groove wall; the side plate 2 is arranged on the side of the battery cell group 11, the side plate 2 includes a first plate portion 21, a second plate portion 22 and a connecting portion 25, the connecting portion 25 is connected to the first plate portion 21 and the second plate portion 22; the first plate portion 21 is connected to the side walls of the multiple battery cells, and the second plate portion 22 is connected to the side of the bracket 12 away from the battery cell group 11.

[0036] Based on the above technical solution, the battery pack of the present application is provided with a cell group 11 and a bracket 12. The cell group 11 can provide power for electrical equipment. The cell group 11 is installed on the bracket 12, which can effectively reduce the difficulty of assembly and increase the installation stability of the battery. At the same time, a side plate 2 is installed on the side of the cell group 11, and the side plate 2 has a stepped structure. The first plate portion 21 is arranged close to the cell group 11, thereby reducing the distance between the first plate portion 21 and the cell group 11, and thus making the external cooling system closer to the cell group 11 at the first plate portion 21, thereby improving the heat exchange efficiency at the first plate portion 21, making full use of the space of the side plate 2, ensuring the consistency of battery heat exchange, and improving the heat dissipation performance of the battery. It should be noted that the term "approaching" and "moving away" as used in this embodiment refers to the staggered connection of the first plate portion 21 and the second plate portion 22 in the first direction X. In addition to a right-angled structure similar to a staircase, the connection portion may also include an acute-angled connection, an obtuse-angled connection, an arc-shaped connection, etc., as long as the first plate portion 21 is closer to the battery cell group 11 than the second plate portion 22. The first direction X is the direction in which the side plate 2 approaches or moves away from the battery cell group 11. Preferably, the battery cell group 11 is provided with battery cells 111 arranged along a second direction Y, and the bracket 12 is provided with a plurality of retaining grooves 121 sequentially spaced along the second direction Y. Each battery cell 111 is inserted into each retaining groove 121 in a one-to-one correspondence, and the second direction Y intersects the first direction X. More preferably, the first direction X is perpendicular to the second direction Y. The spaced battery cells 111 can be used to provide power, and the retaining grooves 121 provide mounting locations for the battery cells 111, allowing the battery cells 111 to be stably mounted on the bracket 12.

[0037] Specifically, as shown in Figures 3 and 4, the distance L1 between the first plate portion 21 and the side of the cell group 11, and the distance L2 between the second plate portion 22 and the side of the cell group 11, satisfy the following: 0.1mm ≤ L2 - L1 ≤ 5mm. Simply ensuring that L2 is greater than L1 ensures consistent heat exchange. However, a distance greater than 5mm will result in significant heat dissipation disparity, which can negatively impact battery performance.

[0038] More specifically, as shown in Figures 3 and 4, the distance L1 between the first plate portion 21 and the side of the cell group 11, and the distance L2 between the second plate portion 22 and the side of the cell group 11, satisfy the following: 1mm ≤ L2 - L1 ≤ 2mm. A small offset between L2 and L1 can hinder processing and result in a heat dissipation effect that is not much different from that of a conventional flat plate, failing to achieve the desired heat dissipation effect. Excessive offset can increase the overall structural footprint, and the significant difference in heat dissipation between the first plate portion 21 and the second plate portion 22 can also shorten the battery lifespan.

[0039] More specifically, as shown in Figures 3 and 4 , the spacing L1 between the first plate portion 21 and the side of the cell group 11, and the spacing L2 between the second plate portion 22 and the side of the cell group 11, satisfy the following requirements: 0 ≤ L1 ≤ 3 mm, 0.1 mm ≤ L2 ≤ 5 mm. Further limiting the dimensions of L1 and L2, while still ensuring that L2 is greater than L1, also avoids excessively large or small L1 and L2, which could result in poor or excessive heat dissipation, thereby protecting the battery while ensuring stable operation.

[0040] In some embodiments of the present application, as shown in Figures 2-5 , the second plate portion 22 has a dimension H1 along the height of the cell group 11, and the bracket 12 has a dimension H2 along the height of the cell group 11, satisfying the following: H1 ≥ H2. Because the side panels 2 are stepped, the spacing at the bottom is greater. Therefore, the bracket 12 is shorter than the second plate portion 22, making it easier to fit between the second plate portion 22 and the cell group 11, thereby securing the cell group.

[0041] Specifically, as shown in Figures 2-5, the dimension H1 of the second plate portion 22 along the height of the cell group 11 and the dimension H2 of the bracket 12 along the height of the cell group 11 satisfy the following conditions: 0 ≤ H1 - H2 ≤ 10mm. Conventional battery heights range from 60mm to 65mm. Therefore, a height difference of no more than 10mm between H1 and H2 satisfies the battery height requirement. This parameter setting also takes into account the overall heat dissipation of the battery, ensuring a consistent temperature difference between the upper and lower halves of the battery, further improving heat dissipation performance.

[0042] In some embodiments of the present application, as shown in Figures 2-4, the side plate 2 further includes an upper limit portion 23 and a lower limit portion 24. The upper limit portion 23 is arranged along one end of the first plate portion 21 away from the second plate portion 22 and abuts against the top wall of the battery cell group 11. The lower limit portion 24 is arranged along one end of the second plate portion 22 away from the first plate portion 21 and abuts against the bottom wall of the bracket 12. The arrangement of the upper limit portion 23 and the lower limit portion 24 can better complete the closed installation of the battery. The upper limit portion 23 is stuck on the top of the battery cell group 11, and the lower limit portion 24 is stuck on the bottom of the bracket 12. The bracket 12 is arranged at the bottom of the battery cell group 11, which can well complete the installation. After installation, the upper limit portion 23 and the lower limit portion 24 can also prevent the battery cell 111 from vibrating up and down inside the battery, thereby protecting the battery cell 111.

[0043] Specifically, as shown in Figures 3 and 4, the upper limit portion 23 extends beyond the first plate portion 21 by a dimension W1, and the lower limit portion 24 extends beyond the second plate portion 22 by a dimension W2, satisfying the following: W2 ≥ W1. Because the top of the battery is obstructed by components such as the terminal, the portion W1 where the upper limit portion 23 extends beyond the first plate portion 21 at the top must be smaller than the portion where the lower limit portion 24 extends beyond the second plate portion 22 at the bottom to avoid components at the top of the battery.

[0044] In some embodiments of the present application, as shown in Figures 3 and 4, the first plate portion 21, the second plate portion 22, and the connecting portion 25 are integrally formed. The integrally formed plate has high strength, is easy to form, and is low in cost, and can well meet the performance requirements of the battery side plate.

[0045] In some embodiments of the present application, as shown in Figures 3 and 4, the connecting portion 25 is a broken line transition section or an arc transition section. Both the broken line transition and the arc transition are a type of stepped structure, and both can achieve the requirement that L1 is less than L2. It should be noted that these two transition methods are only preferred embodiments of this solution. Other forms that make the first plate portion 21 closer to the battery cell group than the second plate portion 22 also fall within the scope of protection of this application.

[0046] In some embodiments of the present application, as shown in FIG2 , the present invention further includes: a first thermally conductive structural adhesive layer 3 and a second thermally conductive structural adhesive layer 4 ; the first thermally conductive structural adhesive layer 3 is connected to the first plate portion 21 and the battery cell group 11, and the second thermally conductive structural adhesive layer 4 is connected to the second plate portion 22 and the bracket 12 . The thermally conductive structural adhesive can dissipate heat generated by the battery cell group 11 to the outside world through heat transfer, thereby improving the heat dissipation effect of the battery cell group 11 , wherein the first thermally conductive structural adhesive layer 3 is used to dissipate heat for the battery cell group 11 at the first plate portion 21 , and the second thermally conductive structural adhesive layer 4 is used to dissipate heat for the battery cell group 11 and the bracket 12 at the second plate portion 22 .

[0047] Some embodiments of the present application, as shown in FIG2 , further include: a liquid cooling plate 5 and a third thermally conductive structural adhesive layer 6 . The liquid cooling plate 5 is connected to the side of the first plate portion 21 facing away from the battery cell group 11 via the third thermally conductive structural adhesive layer 6 . The liquid cooling plate 5 is disposed on the first plate portion 21 to better facilitate heat exchange and effectively reduce the temperature of the battery cell group 11 . The third thermally conductive structural adhesive layer 6 effectively improves the heat exchange efficiency between the first plate portion 21 and the liquid cooling plate 5 .

[0048] Specifically, as shown in Figures 2 and 5, UV glue is provided in the retaining groove 121, and the battery cell 111 and the bracket 12 are bonded together by the UV glue. UV glue, also known as photosensitive glue, is a type of structural adhesive that can be quickly bonded and cured by ultraviolet light, thereby improving the curing efficiency between the battery cell 111 and the bracket 12.

[0049] More specifically, as shown in FIG5 , the limiting grooves 121 are provided with glue-blocking protrusions 1211. The glue-blocking protrusions 1211 are disposed adjacent to the top edge of each limiting groove 121 and abut against the sidewalls of the battery cell 111, thereby confining the UV glue within the limiting grooves 121. The glue-blocking protrusions 1211 are disposed within the limiting grooves 121 and affixed to the battery cell 111, forming a glue overflow groove within the limiting grooves 121. This prevents excessive glue from flowing into the gaps between the battery cells 111, which could cause poor heat dissipation in the battery cells 111.

[0050] Specifically, as shown in FIG5 , the bracket 12 includes a panel 122 and a plurality of partitions 123 . The panel 122 defines a receiving cavity 1221 . The partitions 123 are sequentially spaced along the second direction within the receiving cavity 1221 and divide the receiving cavity 1221 into a plurality of limiting grooves 121 . The combination of the panel 122 and the partitions 123 allows for a simple and convenient division of the receiving cavity 1221 into a plurality of limiting grooves 121 , thereby providing a better means for mounting and securing the battery cells 111 .

[0051] Specifically, as shown in Figures 1, 2, 6, and 7, the battery pack further includes two end plates 7, which are respectively disposed on the two end surfaces of the battery cell group 11 along the second direction. The two sides of the side plate 2 along the second direction are respectively welded to the side edges of one end plate 7. The end plates 7 and the side plates 2 are connected by welding, which provides a better and more stable connection. After the end plates 7 and the side plates 2 are welded, a space for accommodating the battery cells 111 is formed, which encloses the battery cells 111 and prevents the battery cells 111 from being directly exposed.

[0052] In some examples of the present application, as shown in Figures 1, 2, and 7, a module cover 8 is further included, which is provided on the top side of the battery cell group 11. The module cover 8 is provided with components such as an FPC board and a cover plate, and plays the role of conducting electrical energy and sealing the battery cell 111.

[0053] The parameter relationship of L2-L1 and H1-H2 of this application is made into a table (unit: mm):

[0054] Example 1

[0055] L2-L1=0.1mm. At this time, the distance between the first plate portion 21 and the side of the battery cell group 11 is smaller than the distance between the second plate portion 22 and the side of the battery cell group 11 by 0.1mm, thereby achieving heat exchange consistency.

[0056] Example 2

[0057] L2-L1=1mm. At this time, the distance between the first plate portion 21 and the side of the battery cell group 11 is 1mm smaller than the distance between the second plate portion 22 and the side of the battery cell group 11, which is conducive to processing. In addition, there is a certain difference in the heat dissipation effect between the first plate portion 21 and the second plate portion 22, which has an ideal heat dissipation effect. At the same time, the offset distance is appropriate and the space occupied is not large.

[0058] Example 3

[0059] L2-L1=5mm. At this time, the distance between the first plate portion 21 and the side of the battery cell group 11 is smaller than the distance between the second plate portion 22 and the side of the battery cell group 11 by 5mm. If the distance is larger, the heat dissipation difference will be too large, affecting the use of the battery.

[0060] Example 4

[0061] L2-L1=0. At this time, the distance between the first plate portion 21 and the side of the battery cell group 11 is smaller than the distance between the second plate portion 22 and the side of the battery cell group 11. There is no distance between the first plate portion 21 and the second plate portion 22. The heat generated at the first plate portion 21 is higher than the heat generated at the second plate portion 22, resulting in different heat exchange efficiencies between the two, and the effect of achieving heat exchange consistency is relatively poor.

[0062] Example 5

[0063] L2-L1=10mm. At this time, the distance between the first plate portion 21 and the side of the battery cell group 11 is smaller than the distance between the second plate portion 22 and the side of the battery cell group 11 by 10mm, resulting in a large difference in heat dissipation between the two. The second plate portion 22 has poor heat dissipation, and therefore the effect of achieving heat exchange consistency is relatively poor.

[0064] Example 6

[0065] H1-H2=5mm. At this time, the dimension H1 of the second plate portion 22 along the height direction of the battery cell group 11 is higher than the dimension H25mm of the bracket 12 along the height direction of the battery cell group 11, which meets the conventional height requirements of the battery and takes into account the heat dissipation effect, so that the temperature difference between the upper and lower parts of the battery tends to be consistent, further improving the heat dissipation performance.

[0066] Example 7

[0067] H1-H2=10mm. At this time, the dimension H1 of the second plate portion 22 along the height direction of the battery cell group 11 is higher than the dimension H2 of the bracket 12 along the height direction of the battery cell group 11 by 10mm. This height is the limit for meeting the conventional height requirements of the battery and the heat dissipation effect. When it is higher than 10mm, the consistency of the heat dissipation effect becomes relatively poor.

[0068] Example 8

[0069] H1-H2=15mm. At this time, the dimension H1 of the second plate portion 22 along the height direction of the battery cell group 11 is higher than the dimension H2 of the bracket 12 along the height direction of the battery cell group 11 by 15mm. This height does not meet the battery height requirement. Due to the relatively large height difference, the consistency of the heat dissipation effect is also relatively poor.

[0070] In summary, the battery pack of the present application is provided with a cell group 11 and a bracket 12. The cell group 11 can provide power for electrical equipment. The cell group 11 is installed on the bracket 12, which can effectively reduce the difficulty of assembly and increase the installation stability of the battery. At the same time, a side plate 2 is installed on the side of the cell group 11, and the side plate 2 has a stepped structure. The first plate portion 21 is arranged close to the cell group 11, thereby reducing the distance between the first plate portion 21 and the cell group 11, and thus making the external cooling system closer to the cell group 11 at the first plate portion 21, thereby improving the heat exchange efficiency at the first plate portion 21, making full use of the space of the side plate 2, ensuring the consistency of battery heat exchange, and improving the heat dissipation performance of the battery.

[0071] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and replacements can be made without departing from the technical principles of the present application. These improvements and replacements should also be regarded as the scope of protection of the present application.

Claims

1. A battery pack, comprising: A battery cell group (11), the battery cell group (11) having a second direction (Y), the battery cell group (11) comprising a plurality of battery cells, the plurality of battery cells being arranged along the second direction (Y), and the side walls of the plurality of battery cells forming a side portion of the battery cell group (11) along the second direction (Y); A bracket (12), the bracket (12) being provided with a plurality of limiting grooves (121) arranged at intervals along the second direction (Y), each of the plurality of battery cells being correspondingly inserted into each of the plurality of limiting grooves (121), each of the plurality of limiting grooves (121) having a groove wall, and a bottom wall and a side wall of each of the plurality of battery cells being connected to each of the groove walls; A side plate (2) is arranged on a side of the battery cell group (11), the side plate (2) comprising a first plate portion (21), a second plate portion (22) and a connecting portion (25), the connecting portion (25) being connected to the first plate portion (21) and the second plate portion (22); the first plate portion (21) is connected to the side walls of the plurality of battery cells, and the second plate portion (22) is connected to a side of the bracket (12) away from the battery cell group (11).

2. The battery pack according to claim 1, wherein: The spacing L1 between the first plate portion (21) and the side portion of the battery cell group (11) and the spacing L2 between the second plate portion (22) and the side portion of the battery cell group (11) satisfy: 0.1 mm ≤ L2-L1 ≤ 5 mm, or 1 mm ≤ L2-L1 ≤ 2 mm.

3. The battery pack according to claim 2, wherein: The distance L1 between the first plate portion (21) and the side portion of the battery cell group (11) and the distance L2 between the second plate portion (22) and the side portion of the battery cell group (11) satisfy the following conditions: 0≤L1≤3mm, 0.1mm≤L2≤5mm.

4. The battery pack according to claim 1, wherein: The dimension of the second plate portion (22) along the height direction of the battery cell group (11) is H1, and the dimension of the bracket (12) along the height direction of the battery cell group (11) is H2, satisfying: H1≥H2, and 0≤H1-H2≤10mm.

5. The battery pack according to claim 1, wherein: The side plate (2) further comprises an upper limit portion (23) and a lower limit portion (24); the upper limit portion (23) is arranged along one end of the first plate portion (21) away from the second plate portion (22), and abuts against the top wall of the battery cell group (11); the lower limit portion (24) is arranged along one end of the second plate portion (22) away from the first plate portion (21), and abuts against the bottom wall of the bracket (12).

6. The battery pack according to claim 5, wherein: The dimension of the upper limit portion (23) extending from the first plate portion (21) is W1, and the dimension of the lower limit portion (24) extending from the second plate portion (22) is W2, satisfying: W2≥W1.

7. The battery pack according to claim 1, wherein: The first plate portion (21), the second plate portion (22), and the connecting portion (25) are integrally formed.

8. The battery pack according to claim 1, wherein: The connecting portion (25) is a broken line transition section or an arc transition section.

9. The battery pack according to claim 1, wherein: Also includes: A first heat-conducting structural adhesive layer (3) and a second heat-conducting structural adhesive layer (4); The first heat-conducting structural adhesive layer (3) is connected to the first plate portion (21) and the battery cell group (11), and the second heat-conducting structural adhesive layer (4) is connected to the second plate portion (22) and the bracket (12).

10. The battery pack according to claim 1, wherein: Also includes: A liquid cooling plate (5) and a third heat-conducting structural adhesive layer (6), wherein the liquid cooling plate (5) is connected to a side of the first plate portion (21) facing away from the battery cell group (11) via the third heat-conducting structural adhesive layer (6).

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