Battery module and battery pack

Abstract

The application relates to the technical field of batteries, and provides a battery module and a battery pack, the battery module comprising: a plurality of battery cells, the battery cell comprising a shell, a pole and an explosion-proof valve, the shell being provided with a first end face, the pole and the explosion-proof valve being arranged on the first end face, and the plurality of battery cells being arranged in sequence along the width direction of the first end face; a busbar, the poles of two battery cells arranged in the width direction being connected through the busbar, one side of the busbar away from the first end face being used for being pasted with a box body of the battery pack through glue, a part of the busbar between the two poles being provided with a bending part, and a glue overflow groove being formed on the side of the busbar away from the first end face and corresponding to the position of the bending part. The bending part can avoid tearing of the welding part between the busbar and the pole when the battery cell expands, can reduce or avoid glue overflow to the first end face when the busbar is pasted with the box body through glue, and is beneficial to avoiding the problem that the glue covers the explosion-proof valve on the first end face and causes the explosion-proof valve to be unable to open.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a battery module and a battery pack. Background Technology

[0002] The battery pack includes a housing and battery modules assembled inside the housing. Each battery module consists of multiple cells, which are connected in series and parallel via busbars. The housing of the battery pack provides physical support for the battery modules, protecting them from external impacts, pressure, and other damage, while also preventing the intrusion of moisture, dust, and other impurities.

[0003] In traditional battery pack structures, a certain gap is typically maintained between the busbar and the casing, resulting in low energy density and poor heat dissipation efficiency. To address this, related technologies bond the busbar and casing together with thermally conductive adhesive, which increases the cell volume to improve energy density and also enhances the battery pack's heat dissipation. However, after multiple charge-discharge cycles, the cell expands, putting strain on the busbar and causing poor connection between the busbar and the terminals. Summary of the Invention

[0004] This invention provides a battery module and a battery pack to solve the problem in related technologies where the expansion of the battery cells in the battery pack pulls on the busbar, causing poor connection between the busbar and the terminal post.

[0005] This invention provides a battery module, comprising:

[0006] Multiple battery cells, each battery cell including a housing, a terminal post and an explosion-proof valve, the housing having a first end face, the terminal post and the explosion-proof valve being disposed on the first end face, and the multiple battery cells being arranged sequentially along the width direction of the first end face;

[0007] The busbar connects the terminals of two cells arranged along the width direction. The side of the busbar away from the first end face is used to bond with the battery pack housing by adhesive. The portion of the busbar between the two terminals is provided with a bend. An overflow groove is formed on the side of the busbar away from the first end face corresponding to the position of the bend.

[0008] A protrusion is formed on the side of the busbar near the first end face, corresponding to the position of the bend. In the direction of the protrusion, the distance between the bend and the first end face is h, where h ≥ 0.3 mm.

[0009] According to a battery module provided by the present invention, the number of the bending portions is multiple, and the multiple bending portions are arranged at intervals along the width direction.

[0010] According to a battery module provided by the present invention, the number of the bending portions is two, the bending portions have a bending surface close to the first end face, the profile length of the bending surface on the cross section perpendicular to the first end face and extending along the width direction is L1, the straight-line distance between the two ends of the bending surface in the width direction is L, and L1-L≥0.15mm.

[0011] According to a battery module provided by the present invention, the distance between the bent portion and the terminal post in the width direction is d, where d ≥ 0.5 mm.

[0012] According to a battery module provided by the present invention, the bent portion has an arc-shaped cross-section that is perpendicular to the first end face and extends along the width direction.

[0013] According to a battery module provided by the present invention, the overflow groove has multiple pits distributed therein.

[0014] According to a battery module provided by the present invention, the busbar is further provided with two alignment holes, and the two alignment holes are respectively aligned with the terminals of two adjacent battery cells.

[0015] A battery module according to the present invention further includes:

[0016] A wire harness plate is located between the busbar and the first end face. The busbar has a fixing hole, and the wire harness plate and the busbar are fixedly connected by a riveting member passing through the fixing hole.

[0017] This invention provides a battery pack, comprising:

[0018] The housing has a first plate portion and a second plate portion that are arranged opposite to each other;

[0019] In any of the above-mentioned battery modules, the battery module is disposed in the housing, and the outer shell also has a second end face opposite to the first end face, and the first end face is also provided with a protrusion; the protrusion is supported and connected to the first plate, the second end face is supported and connected to the second plate, and the busbar is fixed to the first plate by adhesive bonding.

[0020] The battery module and battery pack provided by this invention have a bend in the busbar, and an overflow groove is formed on the side of the busbar away from the first end face corresponding to the bend. The bend can buffer the expansion of the battery cell to prevent tearing at the weld between the busbar and the terminal post, ensuring a reliable connection between the busbar and the terminal post. During the assembly of the battery module and the battery pack housing, when the busbar and the housing are glued together, the bend can also reduce or prevent glue overflow onto the first end face, thereby helping to avoid the problem of glue covering the explosion-proof valve on the first end face and preventing the explosion-proof valve from failing to open. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a partial structural schematic diagram of the battery module provided by the present invention.

[0023] Figure 2 yes Figure 1 A partially enlarged schematic diagram of the battery module.

[0024] Figure 3 This is a schematic diagram of the busbar structure of the battery module provided by the present invention.

[0025] Figure 4 This is one of the structural schematic diagrams of the battery pack provided by the present invention.

[0026] Figure 5 yes Figure 4 Sectional view at AA.

[0027] Figure 6 This is a schematic diagram of the structure of the battery cell in the battery pack provided by the present invention.

[0028] Figure 7 This is the second schematic diagram of the battery pack provided by the present invention.

[0029] Figure 8 This is the third schematic diagram of the battery pack provided by the present invention.

[0030] Figure 9 This is one of the schematic diagrams showing the arrangement of the battery cells in the battery pack provided by the present invention.

[0031] Figure 10 This is the second schematic diagram of the cell arrangement in the battery pack provided by the present invention.

[0032] Figure label:

[0033] 11. First plate; 12. Second plate; 2. Battery cell; 20. Outer shell; 21. Housing; 22. Cover plate; 221. First end face; 222. Second end face; 223. Protrusion; 2231. Connecting surface; 23. Terminal post; 24. Explosion-proof valve; 3. Busbar; 31. Bending part; 311. Glue overflow groove; 312. Bending surface; 32. First connecting part; 33. Second connecting part; 34. Fixing hole; 35. Alignment hole; 4. Glue. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0035] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "first" and "second" are numbered for the purpose of clearly identifying product components and do not represent any substantial difference. The terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances. Furthermore, "multiple" means two or more. In the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0036] The following is combined with Figures 1-10 The present invention describes the battery module and battery pack.

[0037] like Figure 1 , Figure 2 and Figure 5As shown, the battery module provided in this embodiment of the invention includes multiple battery cells 2 and a busbar 3. Each battery cell 2 includes a housing 20, terminals 23, and an explosion-proof valve 24. The housing 20 has a first end face 221, and the terminals 23 and the explosion-proof valve 24 are disposed on the first end face 221. Multiple battery cells 2 are arranged sequentially along the width direction of the first end face 221. The terminals 23 of two battery cells 2 arranged along the width direction are connected by the busbar 3. The side of the busbar 3 away from the first end face 221 is used to bond with the battery pack housing using adhesive 4. A bending portion 31 is provided on the portion of the busbar 3 located between two terminals 23. An overflow groove 311 is formed on the side of the busbar 3 away from the first end face 221 corresponding to the position of the bending portion 31.

[0038] Among them, see Figure 6 The outer casing 20 of the battery cell 2 includes a housing 21 and a cover plate 22. The electrode group of the battery cell 2 is located in the cavity formed by the housing 21 and the cover plate 22. The outer casing 20 protects the internal components of the battery cell 2 and can withstand certain external impacts.

[0039] In some alternative embodiments, such as Figure 6 As shown, the first end face 221 is formed on the cover plate 22. The cover plate 22 is provided with a through hole for mounting the pole post 23. The pole post 23 passes through the through hole on the cover plate 22 and is installed in the cover plate 22. A part of the pole post 23 is located in the receiving cavity and connected to the pole tab of the pole group, and a part protrudes from the outside of the cover plate 22 to form the pole post 23 terminal.

[0040] In other embodiments, a first end face 221 is formed on the housing 21, and the housing 21 has a through hole for mounting the pole post 23. The pole post 23 passes through the through hole in the housing 21 and is inserted into the housing 21. A portion of the pole post 23 is located in the receiving cavity and connected to the electrode tab of the electrode assembly, while a portion protrudes from the outside of the housing 21 to form a terminal of the pole post 23.

[0041] In this battery module, the terminals 23 of multiple battery cells 2 are connected in series and parallel via busbar 3 to form a battery module. The busbar 3 on the battery module located inside the battery pack housing is bonded to the housing with adhesive 4 to achieve thermally conductive connection between the busbar 3 and the housing.

[0042] The length and width directions of the first end face 221 are as follows: Figure 6As shown. When the busbar 3 is bonded to the housing with adhesive 4, the adhesive 4 between the busbar 3 and the housing may overflow along the width direction of the first end face 221 and flow into the overflow groove 311. The overflow groove 311 can hold a certain amount of adhesive to prevent the adhesive from overflowing onto the explosion-proof valve 24 on the first end face 221 and affecting the opening pressure of the explosion-proof valve 24 or causing the explosion-proof valve 24 to fail to open. As the number of charge and discharge cycles accumulates, the battery cells 2 connected to both ends of the busbar 3 will expand in volume, causing the distance between the terminals 23 of the two battery cells 2 in the width direction to gradually increase. The bent part 31 on the busbar 3 will be straightened accordingly, that is, the busbar 3 will be stretched in the width direction, thereby playing a buffering role and preventing the welding joint between the busbar 3 and the terminal 23 from tearing, ensuring a reliable connection between the busbar 3 and the terminal 23.

[0043] Specifically, the busbar 3 is a plate-shaped component with a first connecting portion 32 and a second connecting portion 33 arranged in the width direction. The first connecting portion 32 is welded to the terminal 23 of one battery cell 2, and the second connecting portion 33 is welded to the terminal 23 of another battery cell 2. A bent portion 31 is located between the first connecting portion 32 and the second connecting portion 33. The first connecting portion 32 and the second connecting portion 33 are respectively bonded to the housing with adhesive. On the side of the busbar 3 near the first end face 221, the bent portion 31 protrudes towards the first end face 221 relative to the first connecting portion 32 and the second connecting portion 33; correspondingly, on the side of the busbar 3 away from the first end face 221, the bent portion 31 is recessed towards the first end face 221 relative to the first connecting portion 32 and the second connecting portion 33 to form an overflow groove 311.

[0044] The battery module provided in this embodiment of the invention has a bend 31 on the busbar 3, and an overflow groove 311 is formed on the side of the busbar 3 away from the first end face 221 corresponding to the bend 31. The bend 31 can buffer the expansion of the cell 2 to avoid tearing at the weld between the busbar 3 and the terminal 23, ensuring a reliable connection between the busbar 3 and the terminal 23. During the assembly of the battery module and the battery pack housing, when the busbar 3 and the housing are glued together, the bend 31 can also reduce or prevent glue from overflowing onto the first end face 221, which helps to avoid the problem of glue covering the explosion-proof valve 24 on the first end face 221 and causing the explosion-proof valve 24 to be unable to open.

[0045] To further improve the energy density of the battery pack, related technologies reduce the height of the terminal post 23 to obtain a larger cell volume. However, with the reduced height of the terminal post 23, in order to avoid interference between the bent portion 31 and the first end face 221, the bending amplitude of the bent portion 31 on the busbar 3 must be reduced. This reduces the buffering effect of the bent portion 31 and decreases the capacity of the overflow groove 311, making it easier for the weld between the busbar 3 and the terminal post 23 to tear and for adhesive to overflow onto the first end face 221.

[0046] In some embodiments of the present invention, the number of bends 31 is multiple, and the multiple bends 31 are arranged at intervals along the width direction of the first end face 221. By providing multiple bends 31, while ensuring that the busbar 3 has the same stretch length in the width direction, the bending amplitude of a single bend 31 can be reduced, that is, the height of the bend 31 protruding toward the first end face 221 can be reduced, thus avoiding interference between the bend 31 and the first end face 221.

[0047] Wherein, when the dimension of the bending part 31 in the width direction of the first end face 221 is fixed, the bending range of the bending part 31 can be determined according to the height of the pole post 23, and the number of bending parts 31 can be specifically determined according to the width dimension of the first end face 221. The larger the width of the first end face 221, the larger the volume of the cell 2, the greater its expansion, and the longer the required busbar 3 stretching length.

[0048] like Figure 2 As shown, in this embodiment of the invention, a protrusion is formed on the side of the busbar 3 near the first end face 221, corresponding to the position of the bend 31. In the protruding direction of the protrusion, the distance between the bend 31 and the first end face 221 is h, where h ≥ 0.3 mm.

[0049] To maximize the buffering effect of the bending portion 31, the bending radius of the bending portion 31 will be set as large as possible, given sufficient space. In this embodiment, by setting a safety distance h between the bending portion 31 and the first end face 221, structural interference between the bending portion 31 and the first end face 221 can be avoided. This prevents the bending portion 31 from pressing against the insulating film or insulating sheet on the outer shell 20, thus avoiding damage to the insulating film or insulating sheet and subsequent insulation failure.

[0050] Furthermore, such as Figure 2 As shown, there are two bending portions 31. Each bending portion 31 has a bending surface 312 close to the first end face 221. The profile length of the bending surface 312 on the cross-section perpendicular to the first end face 221 and extending along the width direction of the first end face 221 is L1. The straight-line distance between the two ends of the bending surface 312 in the width direction of the first end face 221 is L, and L1-L≥0.15mm.

[0051] Wherein, the straight-line distance L between the two ends of the bending surface 312 in the width direction of the first end face 221 is the length of the bent portion 31 before it is stretched, and the length L1 of the bending surface 312 along its bending direction is the length of the bent portion 31 after it is straightened. L1-L represents the length that the bent portion 31 can be stretched. When L is constant, the longer this length, the greater the bending amplitude of the bent portion 31, and the greater its buffering effect. If L1-L is too small, the buffering effect is poor; the maximum value of L1-L is limited by the height of the pole post 23.

[0052] See Figure 2 In some embodiments of the present invention, the distance between the bent portion 31 and the pole post 23 in the width direction of the first end face 221 is d, where d ≥ 0.5 mm. If the distance between the bent portion 31 and the pole post 23 is too small, interference may easily occur when the busbar 3 and the pole post 23 are assembled, causing damage to the pole post 23.

[0053] In some embodiments of the present invention, the thickness of the busbar 3 is 0.5mm to 2mm. If the thickness of the busbar 3 is too small, it will affect the current-carrying area of ​​the busbar 3; if the thickness of the busbar 3 is too large, it will increase the weight of the battery pack.

[0054] like Figure 2 As shown, in this embodiment of the invention, the shape of the cross-section of the bent portion 31, which is perpendicular to the first end face 221 and extends along the width direction of the first end face 221, is arc-shaped.

[0055] It is understandable that the cross-sectional shape of the glue overflow groove 311 extending perpendicularly to the first end face 221 and along the width direction of the first end face 221 is arc-shaped. Similarly, the cross-sectional shape of the bent portion 31 on the side away from the glue overflow groove 311 extending perpendicularly to the first end face 221 and along the width direction of the first end face 221 is arc-shaped. That is, the protrusion formed by the bent portion 31 on the side of the manifold 3 near the first end face 221 is an arc-shaped protrusion, and the glue overflow groove 311 formed by the bent portion 31 on the side of the manifold 3 away from the first end face 221 is an arc-shaped groove. This allows for a more uniform stress distribution on the bent portion 31, reducing stress concentration at the bent portion 31.

[0056] In some embodiments of the present invention, the overflow groove 311 has multiple recesses distributed within it. These recesses increase the contact area between the overflow groove 311 and the adhesive, and can also be used to contain adhesive overflowing into the overflow groove 311, thus improving the anti-overflow effect. Optionally, the recesses can be configured as arc-shaped or spherical recesses.

[0057] In some embodiments of the present invention, the busbar 3 is further provided with two alignment holes 35, which are aligned one-to-one with the terminals 23 of two adjacent battery cells 2. Specifically, the first connecting portion 32 and the second connecting portion 33 of the busbar 3 are each provided with an alignment hole 35. During the assembly of the busbar 3 and the battery cells 2, the two alignment holes 35 on the busbar 3 are aligned with the terminals 23 of the two battery cells 2 to ensure that the relative positions of the busbar 3 and the terminals 23 are accurate. After the alignment is completed, the busbar 3 and the terminals 23 are welded.

[0058] The battery module provided in this embodiment of the invention also includes a wiring harness board, which is located between the busbar 3 and the first end face 221. Figure 3 As shown, the busbar 3 has a fixing hole 34, and the wiring harness plate and the busbar 3 are fixedly connected by a riveting piece passing through the fixing hole 34. Optionally, both the first connecting part 32 and the second connecting part 33 are provided with fixing holes 34. When assembling the battery module, multiple busbars 3 can be riveted and fixed to the wiring harness plate by the riveting piece to form an integral assembly. Then, the busbars 3 on the integral assembly are welded to the terminal posts 23 of the battery cell 2, simplifying the installation steps.

[0059] like Figure 4 and Figure 6 As shown, this embodiment of the invention also provides a battery pack, which includes a housing and a battery module as described in any of the above embodiments. The housing has a first plate portion 11 and a second plate portion 12 disposed opposite to each other, and the battery module is disposed inside the housing. The outer casing 20 also has a second end face 222 opposite to the first end face 221, and the first end face 221 is further provided with a protrusion 223. The protrusion 223, the terminal post 23, and the explosion-proof valve 24 are arranged along the length direction of the first end face 221. The protrusion 223 is supported and connected to the first plate portion 11, and the second end face 222 is supported and connected to the second plate portion 12. The busbar 3 is bonded to the first plate portion 11 with adhesive.

[0060] When the first end face 221 is formed on the cover plate 22, the protrusion 223 can be integrally stamped from the cover plate 22, or it can be welded to the cover plate 22 as an independent structural component. When the first end face 221 is formed on the housing 21, the protrusion 223 can be integrally stamped from the housing 21, or it can be welded to the housing 21 as an independent structural component.

[0061] The first end face 221 of the outer casing 20 of the battery cell 2 faces the first plate portion 11, and the second end face 222 faces the second plate portion 12. The protrusion 223 on the first end face 221 is supported and connected to the first plate portion 11, and the second end face 222 is supported and connected to the second plate portion 12. That is, the outer casing 20 of the battery cell 2 is supported and disposed between the first plate portion 11 and the second plate portion 12.

[0062] The convex hull 223 can be directly connected to the first plate portion 11 (see...). Figure 7 and Figure 8 It can also be connected via an intermediate medium (see...). Figure 4 The purpose is to allow load transfer between the first plate portion 11 and the protrusion 223. The second end face 222 can be directly connected to the second plate portion 12, or it can be connected through an intermediate medium, so as to allow load transfer between the second plate portion 12 and the second end face 222.

[0063] When the protrusion 223 is in direct contact with the first plate 11, the heat of the battery cell 2 can be transferred to the first plate 11 through the protrusion 223, thereby cooling the battery cell 2. Similarly, when the second end face 222 is in direct contact with the second plate 12, the heat of the battery cell 2 can be transferred to the second plate 12 through the second end face 222, thereby cooling the battery cell 2.

[0064] When the protrusion 223 is connected to the first plate portion 11 through an intermediate medium, the intermediate medium can be a thermally conductive medium to facilitate the transfer of heat from the battery cell 2 to the first plate portion 11 via the protrusion 223. Similarly, when the second end face 222 is connected to the first plate portion 11 through an intermediate medium, the intermediate medium can be a thermally conductive medium to facilitate the transfer of heat from the battery cell 2 to the second plate portion 12 via the second end face 222. The thermally conductive medium can be an adhesive with certain thermal conductivity properties.

[0065] In traditional battery pack structures, the battery pack relies solely on the rigidity of the first plate 11 to resist external impacts. Because the first plate 11 has a large area, insufficient rigidity can easily lead to deformation. To prevent excessive compression of the busbar 3 due to deformation of the first plate 11, a large space needs to be reserved between the busbar 3 and the first plate 11 in the structural design, and supporting foam needs to be placed between the battery module and the first plate 11. Some designs also incorporate concave and convex structures on the first plate 11 to enhance its rigidity and prevent deformation. However, these measures result in a large gap between the battery module and the first plate 11, wasting space. Increasing the thickness of the first plate 11 to increase its rigidity would increase the weight of the battery pack, hindering lightweight design.

[0066] The battery pack provided in this embodiment of the invention features a protrusion 223 on the first end face 221 of the outer casing 20 of the cell 2. This protrusion 223 supports the first plate 11 of the housing, while the second end face 222 supports the second plate 12 of the housing. This allows the outer casing 20 of the cell 2 to act as a supporting element between the first and second plates 11 and 12, preventing significant deformation of the first plate 11 under impact. This reduces the thickness of the first plate 11, lightens the weight of the battery pack, and facilitates lightweight design. Furthermore, it reduces the distance between the busbar 3 and the first plate 11 without compressing the busbar 3 and the terminal post 23, thereby increasing the volume of the cell 2 and fully utilizing the space within the housing, thus improving the energy density of the battery pack. Simultaneously, by bonding the busbar 3 to the first plate 11 with adhesive 4, a thermally conductive connection is formed between the busbar 3 and the terminal post 23 and the first plate 11, improving the heat dissipation efficiency of the battery pack.

[0067] Optionally, the distance between the convex 223 and the first plate 11 is smaller than the distance between the busbar 3 and the first plate 11. This helps to ensure that the convex 223 serves as the main load-bearing part of the cell 2, thereby transmitting the force to the outer casing 20 of the cell 2, avoiding or significantly reducing the force on the busbar 3, protecting the busbar 3 and the terminal post 23, and improving the safety performance of the battery pack.

[0068] It should be noted that the battery cell 2 has two terminals 23, namely a positive terminal and a negative terminal. Optionally, both terminals 23 are located on the first end face 221, see [reference]. Figure 4 , Figure 7 and Figure 8 Alternatively, one terminal post 23 may be located on the first end face 221, and the other terminal post 23 may be located on the second end face 222. If the second end face 222 also has a terminal post 23, it may also have a protrusion 223 spaced apart from the terminal post 23, and the second end face 222 is supported and connected to the second plate portion 12 via the protrusion 223. The distance between the protrusion 223 on the second end face 222 and the second plate portion 12 may also be less than the distance between the corresponding busbar 3 and the second plate portion 12.

[0069] like Figure 7 As shown, in some embodiments of the present invention, the distance between the first end face 221 and the first plate portion 11 in the direction perpendicular to the first end face 221 is H1, the thickness of the busbar 3 in the direction perpendicular to the first end face 221 is H2, and the height of the pole post 23 relative to the first end face 221 is H3, 0.1mm≤H1-H2-H3≤5mm.

[0070] H1-H2-H3 represent the distances between the busbar 3 and the first plate 11. If this distance is too small, the busbar 3, as the main load-bearing component, is prone to weld damage, causing deformation of the terminal 23 and resulting in air leakage. If the distance is too large, it is not conducive to the full utilization of the space inside the casing, affecting the volume of the cell 2 and the improvement of the battery pack's energy density. Optionally, the distance between the busbar 3 and the first plate 11 can be 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, or 5mm.

[0071] Table 1: Battery pack pressure test results under different H1 values

[0072]

[0073] Using a battery pack with H2 of 1 mm and H3 of 3.2 mm as the test object (see Cases 1-13 in Table 1), the battery pack was subjected to pressure tests under different H1 values, and the test results are shown in Table 1.

[0074] As shown in Table 1, when H1-H2-H3 < 0.1mm (see Case 1 in Table 1), the distance between busbar 3 and the first plate 11 is too small, the protrusion 223 does not bear any force and does not provide support. Busbar 3 and terminal post 23 serve as the main support components. After the battery pack is disassembled, busbar 3 deforms, and cell 2 fails the helium test. When 0.1mm ≤ H1-H2-H3 ≤ 5mm (see Cases 2-12 in Table 1), the protrusion 223 serves as the main support component. After the battery pack is disassembled, busbar 3 does not show significant deformation, and cell 2 passes the helium test. When H1-H2-H3 > 5mm (see Case 13 in Table 1), the protrusion 223 serves as the main support component. After the battery pack is disassembled, busbar 3 does not show significant deformation, and cell 2 passes the helium test. However, the height of the protrusion 223 is relatively high, which is not conducive to improving the volumetric energy density of the battery pack.

[0075] Furthermore, with 0.1mm≤H1-H2-H3≤5mm, battery packs with different H2 and H3 were used as test objects (see Cases 14~17 in Table 1). The test results all showed that the convex 223 served as the main support component. After the battery pack was disassembled, the busbar 3 did not show obvious deformation, and the cell 2 passed the helium test.

[0076] like Figure 6 As shown, in some embodiments of the present invention, the side of the convex hull 223 away from the first end face 221 is the connecting surface 2231, and the connecting surface 2231 is supported and connected to the first plate portion 11. The number of convex hulls 223 is at least one, the total area of ​​the connecting surfaces 2231 of all convex hulls 223 is S1, the area of ​​the first end face 221 is S0, and 0.1≤S1 / S0≤0.9.

[0077] It should be noted that the area of ​​the first end face 221 is the sum of the length and width of the first end face 221 minus the area of ​​the through hole on it.

[0078] The connecting surface 2231 is the side of the protrusion 223 away from the first end face 221, and also the side of the protrusion 223 facing the first plate portion 11. The connecting surface 2231 is supported and connected to the first plate portion 11, bearing the load transmitted by the first plate portion 11. In this embodiment, by setting the total area S1 of the connecting surfaces 2231 of all the protrusions 223 to between 0.1 and 0.9 times the area of ​​the first end face 221, the overall support strength of all the protrusions 223 can be guaranteed. If S1 is set too small, the overall support capacity of the protrusions 223 will be insufficient, and the ability to resist impact and vibration will be insufficient; if S1 is set too large, there will be insufficient space left for the installation of the pole post 23 and the explosion-proof valve 24, affecting the design of the pole post 23 and the explosion-proof valve 24.

[0079] In some embodiments of the present invention, the area of ​​the connecting surface 2231 is S1', where S1' ≥ 10 mm. 2 That is, the area of ​​the connecting surface 2231 of a single convex hull 223 is at least 10 mm. 2 This ensures the support strength of a single convex hull 223 and reduces the risk of deformation of a single convex hull 223 under local pressure.

[0080] Table 2: Results of battery pack vibration and shock tests under different S1 and S1' conditions

[0081]

[0082] With S0 as 10000mm 2 The battery pack was used as the test object (see Cases 1-12 in Table 2). Vibration and shock tests were performed on the battery pack with different values ​​of S1 and S1'. The test results are shown in Table 2.

[0083] As shown in Table 2, when S1 / S0 < 0.1 (see Case 2 in Table 2), busbar 3 deforms after the battery pack vibration and shock test. When 0.1 ≤ S1 / S0 ≤ 0.9 (see Cases 3-11 in Table 2), neither the convex pack 223 nor busbar 3 deforms after the battery pack vibration and shock test, and cell 2 passes the helium test. When S1 / S0 > 0.9 (see Case 12 in Table 2), neither the convex pack 223 nor busbar 3 deforms after the battery pack vibration and shock test, and cell 2 passes the helium test, but it has a significant impact on the design of terminal post 23 and explosion-proof valve 24.

[0084] When S1'≥10mm 2 When (see Cases 2-16 in Table 2), no deformation was observed in convex bulge 223 during the vibration and impact test. When S1' < 10 mm2 At that time (see Case 1 in Table 2), the convex hull 223 deformed during the vibration and impact test.

[0085] Furthermore, with 0.1≤S1 / S0≤0.9, battery packs with different S0 and S1 were used as test objects (see Cases 13~16 in Table 2). The results showed that after the battery pack vibration and shock test, the convex 223 and busbar 3 did not deform, and the cell 2 passed the helium test.

[0086] Furthermore, the connecting surface 2231 of the convex hull 223 is provided with reinforcing ribs to improve the structural strength of the convex hull 223.

[0087] like Figure 4 As shown, in some embodiments of the present invention, the connecting surface 2231 is bonded and fixed to the first plate portion 11 by adhesive 4, so that multiple battery cells 2 in the housing can be connected into a whole through the first plate portion 11, and a heat-conducting connection is formed between the convex bulge 223 and the first plate portion 11.

[0088] The total area of ​​all connecting surfaces 2231 is S1, and the total area of ​​adhesive 4 on all connecting surfaces 2231 is S2. S2 / S1≥0.5, meaning the total area of ​​adhesive 4 on all connecting surfaces 2231 is at least 0.5 times the total area of ​​connecting surfaces 2231 of all protrusions 223. This ensures the bonding strength between the battery module and the first plate 11, preventing adhesive layer cracking under impact and vibration. It also helps ensure stable contact between each protrusion 223 and the first plate 11, allowing the load acting on the first plate 11 to be transferred to each protrusion 223, preventing damage to the battery cell 2 due to excessive local pressure. Furthermore, it helps ensure the heat conduction area between the battery module and the first plate 11, guaranteeing the heat dissipation performance of the battery pack.

[0089] Furthermore, the area of ​​the adhesive 4 on each connecting surface 2231 is S2', and S2' / S1'≥0.5. This ensures reliable bonding between the individual protrusion 223 and the first plate portion 11, while also ensuring the contact area between the individual protrusion 223 and the first plate portion 11, which is beneficial for load and heat transfer.

[0090] Based on the above embodiment, the thickness of the adhesive layer between the connecting surface 2231 and the first plate portion 11 is T, where 0.5mm ≤ T ≤ 2mm. Optionally, the adhesive layer thickness T is 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, or 1.8mm. Since the protrusion 223 and the first plate portion 11 are insulatedly connected, an adhesive layer that is too thin can easily cause insulation failure; an adhesive layer that is too thick will occupy a large amount of internal space in the battery pack, which is not conducive to improving battery energy density, and instead of increasing adhesion, it will cause a decrease in thermal conductivity.

[0091] Table 3: Vibration and shock test results of battery packs under different S2 / S1, S2' / S1', and T conditions

[0092]

[0093] With S1 as 1600mm 2 S1' is 400mm 2 The battery pack was used as the experimental object (see Cases 1-16 in Table 3). Vibration and shock tests were conducted on the battery pack with different values ​​of S2 and S2'. The experimental results are shown in Table 3.

[0094] As shown in Table 3, when S2 / S1 < 0.5 and S2' / S1' < 0.5 (see Case 1 in Table 3), the adhesive layer cracked after the battery pack vibration and impact test. When S2 / S1 ≥ 0.5 and S2' / S1' ≥ 0.5 (see Cases 2-16 in Table 3), the adhesive layer remained normal and did not crack after the battery pack vibration and impact test.

[0095] When S2 / S1≥0.5 and S2' / S1'≥0.5, and T<0.5mm (see Case 12 in Table 3), the insulation test fails after the battery pack vibration and shock test. When 0.5mm≤T≤2mm (see Cases 13~15 in Table 3), the insulation test passes after the battery pack vibration and shock test. When T>2mm (see Case 16 in Table 3), the insulation test passes after the battery pack vibration and shock test, but the adhesive layer is thicker, resulting in a significant increase in the weight and cost of the battery pack.

[0096] Furthermore, with S2 / S1 and S2' / S1' both greater than 0.5 and T being 1 mm, battery packs with different S1 and S1' were used as experimental subjects (see Cases 17-19 in Table 3). The experimental results all showed that after the battery pack vibration and shock test, the adhesive layer was normal and no cracks appeared, and the insulation test was passed.

[0097] like Figure 4 , Figure 7 and Figure 8 As shown, in this embodiment of the invention, the terminal post 23, the explosion-proof valve 24, and the convex bulge 223 are arranged along the length direction of the first end face 221, with the convex bulge 223 positioned between the terminal post 23 and the explosion-proof valve 24. In this embodiment, the convex bulge 223 separates the terminal post 23 and the explosion-proof valve 24. The convex bulge 223 can prevent the high-temperature gas discharged from the explosion-proof valve 24 from diffusing to the terminal post 23 and the busbar 3. In the event of thermal runaway in the battery cell 2, the convex bulge 223 can also prevent the liquid ejected from the explosion-proof valve 24 from splashing onto the terminal post 23 and the busbar 3, achieving thermoelectric isolation and improving the safety of the battery pack.

[0098] There is a gap between the explosion-proof valve 24 and the first plate portion 11 to ensure that the gas inside the battery cell 2 can be discharged through the explosion-proof valve 24. The height of the explosion-proof valve 24 relative to the first end face 221 can be set to be less than the height of the protrusion 223 relative to the first end face 221, so as to ensure that there is a gap between the explosion-proof valve 24 and the first plate portion 11 when the side of the first plate portion 11 facing the first end face 221 is flat.

[0099] Furthermore, the distance between the explosion-proof valve 24 and the protrusion 223 is b, where b ≥ 10 mm. This prevents the protrusion 223 from affecting the opening pressure of the explosion-proof valve 24 when it acts as a load-bearing component.

[0100] In this embodiment of the invention, the number of protrusions 223 on the first end face 221 can be one or more. The number of protrusions 223 can be specifically determined according to the size of the first end face 221 and the volume and load-bearing capacity of the protrusions 223. When there are multiple protrusions 223, the first end face 221 is provided with multiple protrusions 223 arranged along its length direction; and / or, the first end face 221 is provided with multiple protrusions 223 arranged along its width direction. The dimensions of the multiple protrusions 223 in the length direction and / or width direction of the first end face 221 can be the same or different.

[0101] Based on the existing bulge 223 between the pole post 23 and the explosion-proof valve 24, bulges 223 can be installed at other locations as needed. A bulge 223 may or may not be installed on the side of the pole post 23 furthest from the explosion-proof valve 24. A bulge 223 may or may not be installed on the side of the explosion-proof valve 24 furthest from the pole post 23. See [reference needed]. Figure 7 and Figure 8 .

[0102] In some embodiments of the present invention, a plurality of protrusions 223 are provided on the first end face 221 along its length direction. The explosion-proof valve 24 is located between two adjacent protrusions 223 along the length direction of the first end face 221. It is understood that at least two protrusions 223 are arranged on the first end face 221 along its length direction, wherein at least one protrusion 223 is located between the explosion-proof valve 24 and the pole post 23, and the other protrusions 223 are set according to actual needs.

[0103] See Figure 4 As a specific example, the first end face 221 is provided with two pole posts 23 and two protrusions 223. The two protrusions 223 are located between the two pole posts 23, and the explosion-proof valve 24 is located between the two protrusions 223, so as to realize the thermoelectric isolation between the explosion-proof valve 24 and the two pole posts 23.

[0104] See Figure 8As a specific example, the first end face 221 is provided with two pole posts 23 and two protrusions 223. The two pole posts 23 are located on the same side of the two protrusions 223, and the explosion-proof valve 24 is located between the two protrusions 223. One of the protrusions 223 is used to prevent the material ejected by the explosion-proof valve 24 from reaching the pole post 23 of the battery cell 2, thereby achieving thermoelectric isolation of the battery cell 2 itself. In the case where multiple battery cells 2 are arranged along the length of the first end face 221 inside the housing, the other protrusion 223 can be used to prevent the material ejected by the explosion-proof valve 24 from reaching the adjacent battery cell 2, thereby achieving thermoelectric isolation between two adjacent battery cells 2.

[0105] In some embodiments of the present invention, at least a plurality of battery cells 2 are arranged along the width direction of the first end face 221 inside the housing, and the protrusions 223 of the plurality of battery cells 2 are arranged opposite to each other in the width direction of the first end face 221 to form a strip-shaped baffle.

[0106] Specifically, when there is only one protrusion 223 on the first end face 221, the protrusions 223 of multiple battery cells 2 arranged along the width direction of the first end face 221 are arranged to form a strip-shaped baffle. When there are multiple protrusions 223 arranged along the length direction of the first end face 221, the multiple protrusions 223 of multiple battery cells 2 arranged along the width direction of the first end face 221 are arranged one-to-one to form multiple strip-shaped baffles. The strip-shaped baffles can effectively prevent the material ejected from the explosion-proof valve 24 from reaching the terminal post 23 and busbar 3 of the adjacent battery cell 2, and also play a role in guiding the exhaust gas.

[0107] Furthermore, when the explosion-proof valve 24 is located between two adjacent protrusions 223 along the length of the first end face 221, two strip-shaped baffles are formed on both sides of the explosion-proof valve 24 of the plurality of battery cells 2 arranged along the width of the first end face 221. An exhaust channel is defined between the two strip-shaped baffles, the first end face 221, and the first plate portion 11, and the gas discharged from the explosion-proof valve 24 can be discharged to the outside of the battery pack along this exhaust channel.

[0108] In this embodiment of the invention, the protrusion 223 adjacent to the explosion-proof valve 24 is preferably rectangular, which provides good blocking effect against the material ejected from the explosion-proof valve 24. For protrusions 223 in other positions, they can be rectangular, circular, triangular, or rhomboid, etc., depending on requirements or available space.

[0109] In some embodiments of the present invention, two pole posts 23 are provided on the first end face 221. The two pole posts 23 are arranged along the length direction, and the protrusion 223 and the explosion-proof valve 24 are both located between the two pole posts 23. See [reference needed] Figure 4That is, the side of the pole post 23 away from the explosion-proof valve 24 does not have a protrusion 223. The two pole posts 23 can be set close to the two ends of the first end face 221 in the length direction, so as to reserve a large space between the two pole posts 23 to set multiple or large-area protrusions 223, thereby improving the support strength.

[0110] In the battery pack structure, to facilitate the arrangement of the busbar 3, among the multiple series-connected cells 2 arranged along the width direction of the first end face 221, the polarities of the opposing terminals 23 of two adjacent cells 2 are opposite in the width direction of the first end face 221, that is, the positive and negative terminals of two adjacent cells 2 are opposite to each other. To facilitate the dissipation of heat inside the battery pack, the explosion-proof valves 24 of the multiple cells 2 arranged along the width direction of the first end face 221 are also arranged opposite to each other in the width direction of the first end face 221, so that the multiple explosion-proof valves 24 can discharge along the designated exhaust channels.

[0111] like Figure 4 and Figure 6 As shown, in some embodiments of the present invention, two pole posts 23 are provided on the first end face 221, and the two pole posts 23 are arranged along the length direction of the first end face 221. The explosion-proof valve 24 is located at the center of the length direction of the first end face 221, and the two pole posts 23 are symmetrically arranged about the explosion-proof valve 24. It can be understood that a protrusion 223 is provided between the two pole posts 23 and the explosion-proof valve 24. The protrusions 223 on both sides of the explosion-proof valve 24 of the multiple battery cells 2 arranged in the width direction of the first end face 221 are arranged to form two strip-shaped baffles. An exhaust channel is defined between the two strip-shaped baffles, the first end face 221 and the first plate portion 11, and the gas discharged from the explosion-proof valve 24 of the multiple battery cells 2 can be discharged to the outside of the battery pack along the exhaust channel.

[0112] In this embodiment, the explosion-proof valve 24 is positioned at the center along the length of the first end face 221, and the two terminals 23 are symmetrically arranged about the explosion-proof valve 24, allowing the polarity of the terminals 23 in each cell 2 to be set to the same. Among the multiple cells 2 arranged along the width of the first end face 221, each pair of adjacent cells 2 is arranged at 180°, ensuring that the explosion-proof valves 24 of adjacent cells 2 are opposite each other and that the positive and negative terminals are opposite, thus facilitating heat dissipation from the battery pack and the arrangement of the busbar 3. Furthermore, since there is no need to use cells 2 with two terminals 23 of opposite polarity, the production of the cells 2 is simplified.

[0113] Furthermore, the first end face 221 is provided with a plurality of protrusions 223 arranged along its length direction. The explosion-proof valve 24 is located between two adjacent protrusions 223 in the length direction, and the two adjacent protrusions 223 on both sides of the explosion-proof valve 24 are symmetrically arranged about the explosion-proof valve 24. In this way, when multiple battery cells 2 are arranged along the width direction of the first end face 221, arranging each two adjacent battery cells 2 at 180°, it can also ensure that the two adjacent protrusions 223 on both sides of the explosion-proof valve 24 of the multiple battery cells 2 are arranged as two strip-shaped baffles.

[0114] Due to structural design requirements, the two terminals 23 of the battery cell 2 cannot be too close to the two ends of the first end face 221 along its length. If the two terminals 23 were placed close to the two ends, it would waste the length space of the first end face 221. Figure 7 and Figure 8 As shown, in some other embodiments of the present invention, the two pole posts 23 are disposed on the same side of the explosion-proof valve 24 and the protrusion 223, that is, the protrusion 223 is not disposed on the side of the two pole posts 23 away from the explosion-proof valve 24. In this case, one pole post 23 can be disposed closer to the end of the first end face 221, and a larger space can be reserved between the other pole post 23 and the other end of the first end face 221 for the placement of the protrusion 223 and the explosion-proof valve 24. Compared with the pole post 23, the protrusion 223 and the explosion-proof valve 24 can be closer to the end of the first end face 221, thereby increasing the space on the first end face 221 for the placement of the protrusion 223, which is beneficial to increasing the area of ​​the protrusion 223 and improving the support strength of the protrusion 223.

[0115] like Figure 7 As shown, in some embodiments of the present invention, the convex bulge 223 is located between the pole post 23 and the explosion-proof valve 24. It can be understood that all the convex bulges 223 on the first end face 221 are located between the pole post 23 and the explosion-proof valve 24. Specifically, the first end face 221 has a first end and a second end opposite to each other in its length direction. The explosion-proof valve 24 is disposed near the first end, the two pole posts 23 are disposed near the second end, and the convex bulges 223 are concentrated between the pole post 23 and the explosion-proof valve 24. This allows the two pole posts 23 and the explosion-proof valve 24 to be separated by a single convex bulge 223, which helps to increase the area of ​​the single convex bulge 223, thereby improving the supporting strength of the convex bulge 223.

[0116] Furthermore, the explosion-proof valve 24 is positioned near the first end of the first end face 221 along its length, and the distance between the explosion-proof valve 24 and the edge of the first end is 'a', where 'a' ≥ 4 mm. It can be understood that, while ensuring the area and support strength of the bulge 223, the minimum distance between the explosion-proof valve 24 and the edge of the first end face 221 is 4 mm. Since a hole needs to be drilled in the cover plate 22 of the battery cell 2 to install the explosion-proof valve 24, if the distance between the explosion-proof valve 24 and the edge of the first end is too small, the strength of the cover plate 22 near the explosion-proof valve 24 will be low, and the cover plate 22 will be prone to deformation, affecting the opening pressure of the explosion-proof valve 24.

[0117] like Figure 9 and Figure 10 As shown in the embodiment of the present invention, a plurality of battery cells 2 are arranged in the box along the length and width directions of the first end face 221. Any two adjacent battery cells 2 in the length direction are arranged in a mirror symmetrical arrangement about the plane of symmetry perpendicular to the length direction of the first end face 221.

[0118] See Figure 9 When the protrusion 223 is located on the pole post 23 and the explosion-proof valve 24, that is, when there is no protrusion 223 on the side of the explosion-proof valve 24 away from the pole post 23, the explosion-proof valves 24 on two adjacent cells 2 are side by side in the length direction of the first end face 221, and there is no protrusion 223 between the two explosion-proof valves 24. That is, the protrusion 223 between the explosion-proof valve 24 and the pole post 23 blocks the material ejected from the explosion-proof valve 24 from reaching the terminal of the pole post 23, and thermoelectric separation is achieved by the two rows of cells 2 as a whole.

[0119] See Figure 10 When the explosion-proof valve 24 is provided with a protrusion 223 on the side away from the pole post 23, that is, the first end face 221 is provided with a protrusion 223 near its first end, then the outermost protrusions 223 of two adjacent cells 2 in the length direction of the first end face 221 are side by side, and there are two protrusions 223 between the two explosion-proof valves 24. The substances ejected from the explosion-proof valve 24 can be blocked from reaching the adjacent cells 2 through these two protrusions 223, so as to realize the thermoelectric separation between the adjacent cells 2.

[0120] In some embodiments of the present invention, the convex bulge 223 has multiple layers of protrusions stacked in its protruding direction. The convex bulge 223 serves a supporting function and needs to reach a certain height. When the convex bulge 223 is formed by stamping a plate-like part, excessively high single stamping height can easily cause the plate to break or affect the structural strength of the convex bulge 223. This embodiment sets the convex bulge 223 as a multi-layered protrusion structure, which can be formed by multiple stamping processes. This reduces the height of a single stamping, thereby preventing plate breakage and ensuring the structural strength of the convex bulge 223.

[0121] In some embodiments of the present invention, the first plate portion 11 and the second plate portion 12 can be the shell 21 structure of the housing. For example, one of the first plate portion 11 and the second plate portion 12 is the first shell 21 of the housing, and the other is the second shell 21 of the housing. The protrusion 223 is attached to the first shell 21, and the second end face 222 is attached to the second shell 21. The heat of the battery cell 2 is transferred to the shell 21 of the housing through the protrusion 223 and the second end face 222. The shell 21 of the housing is usually made of thermally conductive steel or aluminum. The heat of the battery cell 2 is transferred to the shell 21 of the housing, and heat exchange occurs between the shell 21 and the outside air through convection.

[0122] In other embodiments of the present invention, the first plate portion 11 includes a first housing 21 and a first cold plate, the first cold plate being located between the first housing 21 and the protrusion 223, and the protrusion 223 being in contact with the first cold plate. The second plate portion 12 includes a second housing 21 and a second cold plate, the second cold plate being located between the second housing 21 and a second end face 222, and the second end face 222 being in contact with the second cold plate. The first cold plate and the second cold plate can be any of a liquid-cooled plate, a direct-cooled plate, or a phase-change material cold plate. The heat from the battery cell 2 can be transferred to the first cold plate and the second cold plate through the protrusion 223 and the second end face 222, improving the cooling effect on the battery pack.

[0123] like Figure 4 As shown, in some embodiments of the present invention, the convex bulge 223 is bonded and fixed to the first plate portion 11 by adhesive 4. Specifically, as Figure 6 As shown, the side of the convex bulge 223 away from the first end face 221 is the connecting surface 2231, and the connecting surface 2231 is bonded and fixed to the first plate portion 11 by adhesive 4.

[0124] In some embodiments of the present invention, the convex bulge 223 and the first plate portion 11 are bonded and fixed together by structural adhesive. The structural adhesive has certain thermal conductivity, enabling stable fixing of the convex bulge 223 and the first plate portion 11, and also possesses high strength, capable of withstanding large loads and exhibiting excellent resistance to dynamic loads or impacts. The structural adhesive exhibits minimal deformation under long-term stress, which helps maintain effective support of the convex bulge 223 for the first plate portion 11, thereby protecting the busbar 3 and the terminal post 23.

[0125] In some embodiments of the present invention, the busbar 3 and the first plate portion 11 are bonded and fixed together by thermally conductive adhesive. The thermally conductive adhesive has high thermal conductivity and maintains stable performance over a wide temperature range. This facilitates the rapid transfer of heat from the battery cell 2 through the terminal post 23, the busbar 3, and the thermally conductive adhesive to the first plate portion 11. Simultaneously, the thermally conductive adhesive is deformable under low compressive force, reducing the force exerted by the first plate portion 11 on the busbar 3 and preventing excessive compression of the busbar 3 by the first plate portion 11.

[0126] In the case where the convex 223 is in direct contact with the first plate 11, i.e. the distance between the convex 223 and the first plate 11 is zero, the distance between the busbar 3 and the first plate 11 is greater than zero and the two are bonded and fixed by thermally conductive adhesive. This allows the load acting on the first plate 11 to be preferentially transferred to the outer casing 20 of the cell 2, so as to protect the busbar 3 and the terminal 23.

[0127] When both the convex shank 223 and the busbar 3 are bonded and fixed to the first plate 11 with adhesive 4, the distance between the convex shank 223 and the first plate 11 is less than the distance between the busbar 3 and the first plate 11, resulting in a thinner adhesive layer between the convex shank 223 and the first plate 11 than between the busbar 3 and the first plate 11. Alternatively, both the convex shank 223 and the busbar 3 can be connected to the first plate 11 using thermally conductive adhesive, which improves the thermal conductivity from the cell 2 to the first plate 11; or the convex shank 223 can be connected to the first plate 11 using structural adhesive, and the busbar 3 can be connected to the first plate 11 using thermally conductive adhesive. Both methods allow the load acting on the first plate 11 to be preferentially transferred to the outer casing 20 of the cell 2, thus protecting the busbar 3 and the terminal post 23.

[0128] In some embodiments of the present invention, a glue-free zone is provided on the first end face 221 surrounding the explosion-proof valve 24, and glue overflowing onto the outer periphery of the protrusion 223 and the manifold 3 is located outside the glue-free zone. The distance c from the outer periphery of the explosion-proof valve 24 along its radial direction is c≥3mm.

[0129] When a large adhesive area is required between the connecting surface 2231 or the busbar 3 and the first plate portion 11, adhesive overflow may occur. Since both the convex 223 and the pole post 23 protrude from the first end face 221, an adhesive overflow groove 311 can be formed between two adjacent convex 223s, two adjacent busbars 3, or adjacent convex 223s and busbars 3. This groove can be used to collect adhesive overflowing from the convex 223 or busbar 3. Adhesive overflowing to the outer periphery of the convex 223 and busbar 3 is confined outside the adhesive-free zone to ensure that adhesive does not cover the explosion-proof valve 24, preventing the explosion-proof valve 24 from opening.

[0130] Optionally, the first end face 221 is provided with an annular baffle surrounding the explosion-proof valve 24, and the area enclosed by the annular baffle serves as a glue-free zone. The presence of the annular baffle reduces the precision required to control the amount of glue applied and ensures that excess glue does not cover the explosion-proof valve 24.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery pack, characterized in that, include: The housing has a first plate portion and a second plate portion that are arranged opposite to each other; A battery module, housed within the housing, includes multiple battery cells and a busbar; The battery cell includes a housing, terminals, and an explosion-proof valve. The housing has a first end face and a second end face arranged opposite to each other. The first end face has a protruding bulge that is supported and connected to a first plate. The second end face is supported and connected to a second plate. The terminals and the explosion-proof valve are disposed on the first end face. The bulge, the terminals, and the explosion-proof valve are arranged along the length direction of the first end face. Multiple battery cells are arranged sequentially along the width direction of the first end face. The housing is adapted to be supported and connected to the battery pack housing through the bulge. The terminals of two battery cells arranged along the width direction are connected by the busbar. The side of the busbar away from the first end face is fixed to the first plate by adhesive. The portion of the busbar between the two terminals is provided with a bend. An overflow groove is formed on the side of the busbar away from the first end face corresponding to the position of the bend. The overflow groove is used to collect the adhesive overflowing from the bonding area between the busbar and the housing to prevent the adhesive from overflowing onto the explosion-proof valve. A protrusion is formed on the side of the busbar near the first end face corresponding to the position of the bend. In the protruding direction of the protrusion, the distance between the bend and the first end face is h, where h ≥ 0.3 mm.

2. The battery pack according to claim 1, characterized in that, The number of the bending portions is multiple, and the multiple bending portions are arranged at intervals along the width direction.

3. The battery pack according to claim 1, characterized in that, The number of the bending portions is two, and each bending portion has a bending surface close to the first end face. The profile length of the bending surface on the cross section perpendicular to the first end face and extending along the width direction is L1, and the straight-line distance between the two ends of the bending surface in the width direction is L, where L1-L≥0.15mm.

4. The battery pack according to claim 1, characterized in that, In the width direction, the distance between the bent portion and the pole post is d, where d ≥ 0.5 mm.

5. The battery pack according to claim 1, characterized in that, The bent portion has an arc-shaped cross-section that is perpendicular to the first end face and extends along the width direction.

6. The battery pack according to claim 1, characterized in that, The overflow groove has multiple pits distributed inside.

7. The battery pack according to claim 1, characterized in that, The busbar is also provided with two alignment holes, which are aligned one-to-one with the terminals of the two adjacent battery cells.

8. The battery pack according to claim 1, characterized in that, Also includes: A wire harness plate is located between the busbar and the first end face. The busbar has a fixing hole, and the wire harness plate and the busbar are fixedly connected by a riveting member passing through the fixing hole.

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