A battery pack and an electric device

Abstract

The application discloses a battery pack and a power utilization device, and relates to the technical field of batteries; the battery pack comprises a base plate, end beams and a battery cell group, the battery pack has a first direction and a second direction which are perpendicular to each other, the end beams are arranged on the two sides of the base plate along the first direction, the base plate and the end beams enclose a containing space, the battery cell group is arranged in the containing space, and the battery cell group abuts against the end beams along the first direction; one side of the end beam facing the battery cell group is provided with a first groove, the end beam is welded with the base plate at the first groove, and the first groove is used for containing solder. In this way, the solder used when the end beam is welded with the base plate can be contained in the first groove, the weld formed after the welding is located in the first groove, the end beam and the base plate can be tightly connected while the weld formed by the welding does not interfere with the battery cell group, the possibility that the battery cell group is deformed or even damaged by the weld is reduced, and the stability and reliability of the battery pack are improved.

Description

Technical Field

[0001] This application belongs to the field of battery technology, specifically relating to a battery pack and an electrical device. Background Technology

[0002] Battery packs are the core energy storage units in electric vehicles, energy storage systems and other fields. They are formed by the integration of multiple cell groups, housings, battery management systems and other components. Multiple cell groups are housed in the housings. The housings are key components that protect the safety and stability of the cell groups and need to meet requirements such as mechanical strength, lightweighting, thermal management and sealing.

[0003] In related technologies, the enclosure is usually welded together from structural components such as base plate, side plate, and end beam. When the end beam is welded to the base plate, the weld will bulge towards the side of the battery cell assembly, causing the weld to interfere with the battery cell assembly and even causing deformation of the battery cell assembly. Summary of the Invention

[0004] This application aims to provide a battery pack and electrical device that can solve the problem in the related art where, when welding the end beam to the substrate, the weld may bulge towards the side of the cell assembly, causing the weld to interfere with the cell assembly or even cause deformation of the cell assembly.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, embodiments of this application propose a battery pack, comprising: a substrate, end beams, and a battery cell assembly. The battery pack has a first direction and a second direction that are perpendicular to each other. The end beams are disposed on both sides of the substrate along the first direction. The substrate and the end beams enclose a receiving space. The battery cell assembly is disposed within the receiving space, and the battery cell assembly abuts against the end beams along the first direction. A first groove is provided on the side of the end beam facing the battery cell assembly. The end beam is welded to the substrate through the first groove, and the first groove is used to receive solder.

[0007] Optionally, the end beam includes a support portion and an abutment portion connected to each other. The first groove is provided on the side of the abutment portion facing the cell assembly. The abutment portion is welded to the substrate through the first groove. The support portion is provided on the side of the abutment portion away from the cell assembly. The abutment portion abuts against the cell assembly along a first direction. The abutment portion is provided with a connection hole. The cell assembly is connected to the connection hole.

[0008] Optionally, multiple battery cell groups are provided, and the multiple battery cell groups are arranged along the second direction. The end beam is provided with the first groove at a position corresponding to each battery cell group.

[0009] Optionally, the projection of the first groove along the first direction falls within the projection of the battery cell assembly along the first direction.

[0010] Optionally, the substrate includes a bottom plate and side plates, and the end beams are disposed on both sides of the bottom plate along the first direction. The end beams are welded to the bottom plate through the first groove. The side plates are disposed on both sides of the bottom plate along the second direction and are welded to the bottom plate. The bottom plate, the side plates, and the end beams enclose the receiving space.

[0011] Optionally, the battery pack further includes a connector connected to the substrate. The connector is disposed within the receiving space to divide the receiving space into at least two sub-receiving spaces, each of which contains the battery cell assembly. Along the first direction, one end of the battery cell assembly abuts against the end beam, and the other end of the battery cell assembly abuts against the connector. The connector has second grooves on opposite sides in the first direction, and the connector is welded to the substrate through the second grooves, which are used to accommodate solder.

[0012] Optionally, the projection of the first groove along the first direction at least partially coincides with the projection of the second groove along the first direction.

[0013] Optionally, multiple connectors are provided, and the multiple connectors are spaced apart along the second direction in the accommodating space to divide the accommodating space into multiple sub-accommodating spaces.

[0014] Optionally, the width of the first groove along the second direction is W1, and the width of the battery cell assembly along the second direction is W2, satisfying: 0.4≤W1 / W2≤0.6.

[0015] Optionally, the width W1 of the first groove along the second direction satisfies: 72mm≤W1≤110mm.

[0016] Optionally, the depth of the first groove along the first direction is H1, and the thickness of the abutting portion along the first direction is H2, satisfying: 0.1≤H1 / H2≤0.4.

[0017] Optionally, the depth H1 of the first groove along the first direction satisfies: 2.6mm≤H1≤10mm.

[0018] Optionally, the width of each first groove along the second direction is W1, the number of first grooves in the end beam is n, and the length of the end beam along the second direction is L, satisfying: 0.45≤(n×W1) / L≤0.54.

[0019] Secondly, embodiments of this application provide an electrical device, including: a battery pack as described in any of the preceding claims, the battery pack being used to supply power to the electrical device.

[0020] In embodiments of this application, the battery pack includes a substrate, end beams, and a battery cell assembly. The battery pack has a first direction and a second direction that are perpendicular to each other. The end beams are disposed on both sides of the substrate along the first direction, and the substrate and end beams enclose a receiving space. The battery cell assembly is disposed within the receiving space and abuts against the end beams along the first direction. A first groove is provided on the side of the end beam facing the battery cell assembly, and the end beam is welded to the substrate through the first groove. The first groove is used to accommodate solder. In this way, the solder during the welding of the end beam and the substrate can be contained in the first groove, so that the weld formed after welding is located in the first groove. While ensuring that the end beam and the substrate can be tightly connected, the weld formed by welding will not interfere with the battery cell assembly, reducing the possibility of the battery cell assembly being squeezed, deformed, or even damaged by the weld, thus improving the stability and reliability of the battery pack.

[0021] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0022] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0023] Figure 1 This is a partial schematic diagram of a battery pack according to an embodiment of this application;

[0024] Figure 2 This is a partial exploded view of a battery pack according to an embodiment of this application;

[0025] Figure 3 This is a schematic diagram of the lower end beam installation from one perspective according to an embodiment of this application;

[0026] Figure 4 According to the embodiments of this application Figure 3 Enlarged view of part A in the image;

[0027] Figure 5 This is a schematic diagram of the lower end beam installation from another perspective according to an embodiment of this application;

[0028] Figure 6 This is a schematic diagram of a battery cell assembly according to an embodiment of this application.

[0029] Figure label:

[0030] 1: Substrate; 11: Base plate; 12: Side plate; 2: End beam; 21: First groove; 22: Support part; 23: Abutment part; 231: Connection hole; 3: Battery cell assembly; 4: Accommodation space; 41: Sub-accommodation space; 5: Solder; 6: Connector; 61: Second groove; X: First direction; Y: Second direction. Detailed Implementation

[0031] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0032] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0033] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, 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, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0034] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0035] Before explaining the battery pack and electrical equipment provided in the embodiments of this application, the application scenarios of the battery pack and electrical equipment provided in the embodiments of this application will be specifically described first:

[0036] Battery packs are the core energy storage units in electric vehicles, energy storage systems, and other fields. They are generally integrated from multiple cell groups, a top cover, a lower casing, and a battery management system. Among these, the top cover and lower casing are key components for protecting the safety and stability of the cell groups, and they need to meet requirements such as mechanical strength, lightweight design, thermal management, and sealing.

[0037] In related technologies, the lower housing is constructed from an aluminum alloy or steel base plate, end beams, side plates, and reinforcing ribs, welded together to support the battery cell assembly. During actual operation, to improve the sealing of the lower housing, optimize structural strength to avoid direct impact on the welds, enhance the aesthetics of the lower housing, and reduce weld corrosion, the inner side of the end beam (the side facing the battery cell assembly) is welded to the base plate. However, this welding method results in welds protruding from the end beam (facing the battery cell assembly), which can easily interfere with battery cell assembly assembly and may even cause compression, leading to deformation or damage to the battery cell assembly.

[0038] Therefore, this application provides a battery pack and an electrical device. The battery pack and electrical device provided in this application will be described in detail below with reference to the accompanying drawings and through specific embodiments and application scenarios.

[0039] like Figure 1 As shown, a battery pack according to some embodiments of this application includes: a substrate 1, an end beam 2, and a cell assembly 3. The battery pack has a first direction X and a second direction Y that are perpendicular to each other. The end beam 2 is disposed on both sides of the substrate 1 along the first direction X. The substrate 1 and the end beam 2 enclose a receiving space 4. The cell assembly 3 is disposed in the receiving space 4 and abuts against the end beam 2 along the first direction X. A first groove 21 is provided on the side of the end beam 2 facing the cell assembly 3. The end beam 2 is welded to the substrate 1 through the first groove 21. The first groove 21 is used to receive solder 5.

[0040] In this embodiment, the end beam 2 has a first groove 21 on the side facing the cell assembly 3. The end beam 2 is welded to the substrate 1 at the first groove 21 to accommodate the solder 5 during welding. In this way, the solder 5 during welding of the end beam 2 and the substrate 1 can be accommodated in the first groove 21, so that the weld formed after welding is located in the first groove 21. While ensuring that the end beam 2 and the substrate 1 can be tightly connected, the weld formed by welding will not interfere with the installation of the cell assembly 3, reducing the possibility of the cell assembly 3 being squeezed, deformed or even damaged by the weld, and improving the stability of the battery pack.

[0041] It should be noted that the battery pack has a first direction X and a second direction Y that are perpendicular to each other. The first direction X is the length direction of the battery pack, and in actual use, the first direction X is also the arrangement direction of multiple cells in the same cell group 3. The second direction Y is the width direction of the battery pack, and in actual use, the second direction Y is also the arrangement direction of multiple cell groups 3.

[0042] Understandably, the first direction X and the second direction Y are perpendicular to each other. Specifically, they can be "perpendicular" in the strict sense, meaning that the angle between the first direction X and the second direction Y is 90°; or they can be "approximately perpendicular," specifically meaning that the angle between the first direction X and the second direction Y includes a certain error. Considering the measurement and the error associated with the measurement of a specific quantity (i.e., the limitation of the measurement system), this error is within the acceptable deviation range for a specific value as determined by a person skilled in the art. For example, the angle between the first direction X and the second direction Y is 90° ± 10°.

[0043] In specific applications, such as Figure 2 As shown, there are two end beams 2 (one of which is not shown in the figure). The two end beams 2 are set at both ends of the substrate 1 along the first direction X of the battery pack (i.e. the length direction of the battery pack), thereby forming a protection for the cell assembly 3 and improving the collision protection capability of the battery pack. Each end beam 2 has a first groove 21 on the side facing the cell assembly 3, so that when each end beam 2 is welded to the substrate 1, it is welded to the substrate 1 at the first groove 21.

[0044] It needs to be explained that, such as Figure 2 As shown, the end beam 2 and the substrate 1 enclose a receiving space 4, thereby installing the battery cell assembly 3 within the receiving space 4. The end beam 2 and the substrate 1 can protect the battery cell assembly 3 on the one hand, reducing the possibility of the battery cell assembly 3 being impacted; on the other hand, they can provide dustproof, waterproof and other sealing protection for the battery cell assembly 3. Multiple battery cell assemblies 3 can be provided, and multiple battery cell assemblies 3 are arranged along the second direction Y. Specifically, the number of battery cell assemblies 3 can be 1, 2, 3, 4, 5, etc. The multiple cells in each battery cell assembly 3 are arranged along the thickness direction of the cell, so that the large surface (wide surface) of the cell is adjacent, thereby increasing the number of cells in each battery cell assembly 3, thereby increasing the energy density of the battery pack. The specific number of battery cell assemblies 3 depends on the size of the battery cell assembly 3 and the volume of the receiving space 4. Those skilled in the art can set it according to the actual situation, and this application does not limit it.

[0045] Understandably, in order to improve the sealing between the end beam 2 and the substrate 1, sealant is applied or a sealing strip is added between the area of ​​the end beam 2 where the first groove 21 is not provided and the substrate 1, thereby achieving double protection (welding and sealant) between the end beam 2 and the substrate 1, so as to ensure that the battery pack meets the protection level requirements of relevant regulations.

[0046] In specific applications, the substrate 1 supports the cell assembly 3 in the vertical direction (height direction of the battery pack) and protects the cell assembly 3 in the second direction Y (width direction of the battery pack). The end beam 2 abuts against the end of the cell assembly 3 in the first direction X (length direction of the battery pack), thereby providing a preload to the cell assembly 3. In actual use, the cells in the cell assembly 3 will expand slightly during charging and discharging. The abutment between the end beam 2 and the cell assembly 3 can prevent the cells in the cell assembly 3 from expanding excessively.

[0047] It should be explained that the end beam 2 and the substrate 1 are welded at the first groove 21. Specifically, it can be laser welding or MAG welding (Metal Active Gas Welding), depending on the actual situation. For example, if both the end beam 2 and the substrate 1 are aluminum alloys, laser welding can be used, which results in less deformation during welding. Taking the end beam 2 and the substrate 1 as aluminum alloys and laser welding as an example, during actual welding, the aluminum alloy solder is laser welded at the first groove 21 to form a weld. The aluminum alloy solder (solder 5) can be contained within the first groove 21, so that the weld after the final welding is completed will not be exposed outside the first groove 21. This reduces interference during the installation of the cell pack 3, reduces the possibility of squeezing deformation or even damage to the cell pack 3, and improves the stability and reliability of the battery pack.

[0048] like Figure 2 As shown, in some embodiments of this application, the end beam 2 includes a support portion 22 and an abutment portion 23 connected to each other. A first groove 21 is provided on the side of the abutment portion 23 facing the cell assembly 3. The abutment portion 23 is welded to the substrate 1 through the first groove 21. The support portion 22 is provided on the side of the abutment portion 23 away from the cell assembly 3. The abutment portion 23 abuts against the cell assembly 3 along the first direction X. The abutment portion 23 is provided with a connection hole 231. The cell assembly 3 is connected to the connection hole 231.

[0049] In this embodiment, the abutment portion 23 abuts against the cell assembly 3 along the first direction X, providing a pre-tightening force to the cell assembly 3 along the first direction X to prevent displacement of the cells in the cell assembly 3 due to expansion or contraction during charging and discharging. In other words, the abutment portion 23 can constrain the cell assembly 3. Simultaneously, the first groove 21 is positioned on the side of the abutment portion 23 facing the cell assembly 3. That is, the weld formed at the first groove 21 when welding to the substrate 1 is on the inner side of the end beam 2 (i.e., the side facing the cell assembly 3), which reduces the risk of leakage and improves the overall sealing of the battery pack. This reduces the impact of thermal deformation of the end beam 2 during welding on the flatness of the outer side of the end beam 2 (the side away from the cell assembly 3), making it easier to install the battery pack. The support part 22, located on the side of the abutment part 23 away from the cell assembly 3, can connect with the top cover of the battery pack and protect the abutment part 23 and the cell assembly 3, reducing the risk of weld corrosion and improving the life of the battery pack. The connection hole 231 on the abutment part 23 allows the cell assembly 3 to be connected to the connection hole 231, further improving the installation stability of the cell assembly 3.

[0050] In specific applications, such as Figure 2 As shown, along the first direction X, the abutment part 23 is located between the cell assembly 3 and the support part 22. A connection hole 231 is provided on the top of the abutment part 23. The bolts (not shown in the figure) at the end of the cell assembly 3 can be screwed into the connection hole 231 to further ensure the stability of the cell assembly 3. The support part 22 is provided with multiple threaded holes to cooperate with the top cover for sealing. At the same time, the abutment part 23 and the support part 22 form a "stepped structure", which can save materials and reduce costs on the one hand, and reduce the possibility of interference between the cell assembly 3 and the top cover during installation on the other hand.

[0051] Understandably, the abutment portion 23 and the support portion 22 form a "stepped structure", which can form a structure similar to a "reinforcing rib" and improve the overall bending strength of the end beam 2; at the same time, heat dissipation channels can be set inside the abutment portion 23 and the support portion 22 to improve the overall integration of the battery pack.

[0052] It should be explained that the abutment part 23 and the support part 22 are generally integrally formed by die casting, thus having higher strength.

[0053] like Figure 2 As shown, in some embodiments of this application, multiple battery cell groups 3 are provided, and the multiple battery cell groups 3 are arranged along the second direction Y. The end beam 2 is provided with a first groove 21 at the position corresponding to each battery cell group 3.

[0054] In this embodiment, the end beam 2 is provided with a first groove 21 at the position corresponding to each cell group 3. That is, multiple first grooves 21 are formed on the end beam 2 at intervals. Welding is performed at each first groove 21 to form an "intermittent welding" between the end beam 2 and the substrate 1. On the one hand, the welding stress can be distributed to multiple points of bearing, which improves the fatigue strength of the end beam 2. On the other hand, multiple first grooves 21 are multiple welding points, which can ensure the connection strength between the end beam 2 and the substrate 1. In actual use, when the battery pack is impacted, the end beam 2 is the main load-bearing structure. Therefore, the connection strength between the end beam 2 and the substrate 1 is higher, which can reduce the risk of separation between the end beam 2 and the substrate 1.

[0055] In practical applications, the battery cell group 3 can be configured with 3, 4, 5, 6, etc. The specific number of battery cell groups 3 depends on the volume of the accommodating space 4 and the specific volume of each battery cell group 3. Figure 2 As shown, there are 4 battery cell groups 3; each battery cell group 3 includes multiple battery cells, which are arranged along the first direction X (the thickness direction of the battery cells); the multiple battery cell groups 3 are arranged along the second direction Y.

[0056] It should be noted that the first groove 21 corresponding to each cell group 3 is generally set in the central area of ​​the end of the cell group 3, so that the end beams 2 on both sides of the first groove 21 can abut against the cell group 3, ensuring that the end face of each cell group 3 is subjected to balanced force when it abuts against the end beam 2.

[0057] like Figure 2 As shown, in some embodiments of this application, the projection of the first groove 21 along the first direction X falls within the projection of the cell assembly 3 along the first direction X.

[0058] In this embodiment, by setting the projection of the first groove 21 along the first direction X to fall within the projection of the cell assembly 3 along the first direction X, both ends of the cell assembly 3 along the second direction Y can abut against the end beam 2 when the cell assembly 3 expands during charging and discharging (the first groove 21 is located in the middle area of ​​the end of the cell assembly 3), ensuring uniform stress on the cell assembly 3. At the same time, the welding area at the first groove 21 forms a local rigid node, and the shear stress generated when the cell assembly 3 expands can be absorbed by the weld, improving the stability of the battery pack.

[0059] In a specific application, the projection of the first groove 21 corresponding to each cell group 3 along the first direction X falls within the projection of the cell group 3 along the first direction X. That is, the length of the first groove 21 corresponding to each cell group 3 in the second direction Y is less than the width of the cell group 3 along the second direction Y.

[0060] It should be explained that the projection of the first groove 21 along the first direction X falls within the projection of the cell assembly 3 along the first direction X. That is, the first groove 21 corresponding to the cell assembly 3 is located in the middle area of ​​the cell assembly 3 along the second direction Y. Thus, both ends of the cell assembly 3 along the second direction Y abut against the end beam 2, thereby ensuring that both ends of each cell assembly 3 along the second direction Y are subjected to the preload of the end beam 2, ensuring that the force on each cell assembly 3 is uniform.

[0061] like Figure 2 As shown, in some embodiments of this application, the substrate 1 includes a bottom plate 11 and a side plate 12. The end beam 2 is disposed on both sides of the bottom plate 11 along the first direction X, and the end beam 2 is welded to the bottom plate 11 through the first groove 21. The side plate 12 is disposed on both sides of the bottom plate 11 along the second direction Y and is welded to the bottom plate 11. The bottom plate 11, the side plate 12 and the end beam 2 enclose and form an accommodating space 4.

[0062] In this embodiment, the end beam 2, the bottom plate 11, and the side plate 12 enclose and form an accommodating space 4. The end beam 2 can provide a pre-tightening force to the end of the battery pack 3 along the first direction X. The side plate 12 can provide protection to the battery pack 3 in the second direction Y, isolating the battery pack 3 from the outside world. The bottom plate 11 can bear the weight of the battery pack 3 in the vertical direction (the height direction of the battery pack).

[0063] In specific applications, two end beams 2 are provided, which are respectively located on both sides of the base plate 11 along the first direction X. Two side plates 12 are provided, which are respectively located on both sides of the base plate 11 along the second direction Y. The two end beams 2 and the two side plates 12 are connected end to end to surround the outer periphery of the base plate 11, thereby forming an accommodating space 4 with the base plate 11. In actual use, the end beams 2 are welded to the base plate 11 through the first groove 21, and the side plates 12 are welded to the base plate 11 on the side facing the base plate 11. The end beams 2 and the side plates 12 are also welded, thereby ensuring the sealing of the battery pack. At the same time, in order to further improve the sealing of the battery pack, sealant can be applied to the unwelded parts or sealing strips can be added.

[0064] Understandably, the side plate 12 can be made of aluminum alloy or steel plate, and the bottom end of the side plate 12 can be welded to the base plate 11 by laser welding or MAG welding. In actual processing, the side plate 12 can be welded to the base plate 11 first, then the end beam 2 can be welded to the base plate 11, and then the intersection of the end beam 2 and the side plate 12 can be fully welded at all four corners. This ensures the welding quality and reduces the accumulation of heat deformation during welding.

[0065] like Figure 3As shown, in some embodiments of this application, the battery pack further includes a connector 6, which is connected to the substrate 1. The connector 6 is disposed in the accommodating space 4 to divide the accommodating space 4 into at least two sub-accommodating spaces 41. Each sub-accommodating space 41 is provided with a cell assembly 3. Along the first direction X, one end of the cell assembly 3 abuts against the end beam 2, and the other end of the cell assembly 3 abuts against the connector 6. The connector 6 is provided with second grooves 61 on both sides of the first direction X. The connector 6 is welded to the substrate 1 through the second grooves 61. The second grooves 61 are used to accommodate solder 5.

[0066] In this embodiment, a connector 6 is provided within the accommodating space 4 to divide the accommodating space 4 into at least two sub-accommodating spaces 41 (some sub-accommodating spaces 41 are not shown in the figure). This allows the cell assembly 3 to be arranged in each sub-accommodating space 41, thereby facilitating the division of the entire battery pack into multiple regions. The connector 6 not only serves as a partition between different regions, facilitating the delay of the spread of flames and high-temperature gases during thermal runaway of a single cell and reducing the rate of temperature rise in adjacent regions, but also serves as a "lateral reinforcing rib" of the battery pack, improving the torsional strength of the battery pack. Furthermore, second grooves 61 are provided on opposite sides of the connector 6, allowing the connector 6 to be welded to the base plate 11 through the second grooves 61, so that the solder 5 during welding can be accommodated in the second grooves 61. Similar to the first groove 21 provided on the end beam 2, this reduces interference with the cell assembly 3 and lowers the risk of squeezing deformation or even damage to the cell assembly 3.

[0067] In practical applications, the bottom of connector 6 is welded to the base plate 11, such as... Figure 4 As shown, the second groove 61 is set in a similar manner to the first groove 21. The solder 5 during welding can also be contained in the second groove 61. In practical applications, since the two ends of the battery cell assembly 3 in each sub-accommodation space 41 abut against the end beam 2 and the connector 6 along the first direction X, the possibility of interference can be reduced by setting the second groove 61.

[0068] It should be explained that since the connector 6 can divide the accommodating space 4 into at least two sub-accommodating spaces 41, a second groove 61 is provided on both sides of the connector 6 along the first direction X. This ensures the reliability of the connection between the connector 6 and the base plate 11, while also reducing the possibility of interference with the battery cell group 3 in each sub-accommodating space 41.

[0069] Understandably, the connector 6 can be made of aluminum alloy, steel plate, etc., and those skilled in the art can make the design according to actual needs. This application does not impose any restrictions on this.

[0070] like Figure 3As shown, in some embodiments of this application, the projection of the first groove 21 along the first direction X at least partially overlaps with the projection of the second groove 61 along the first direction X.

[0071] In this embodiment, by setting the projection of the first groove 21 along the first direction X to at least partially overlap with the projection of the second groove 61 along the first direction X, it is convenient to process the first groove 21 and the second groove 61. At the same time, the area of ​​the connector 6 without the second groove 61 can form symmetry or approximately symmetry with the area of ​​the end beam 2 without the first groove 21, so that the two ends of the battery cell assembly 3 along the first direction X are subjected to the same preload by the connector 6 and the end beam 2, respectively, ensuring the uniformity of the force on the battery cell assembly 3 and reducing the possibility of stress concentration.

[0072] In practical applications, the projections of the first groove 21 and the second groove 61 along the first direction X completely coincide, thereby allowing the force generated by collision or vibration to be evenly distributed to the end beam 2 and the connector 6, reducing stress concentration. In addition, it is convenient to arrange the positions of the first groove 21 and the second groove 61 on the end beam 2 and the connector 6, thereby facilitating processing and reducing processing costs. Furthermore, the first groove 21 and the second groove 61 can absorb the expansion difference when the battery cell assembly 3 expands, reducing stress accumulation.

[0073] It should be explained that in practical applications, the number of the first groove 21 and the second groove 61 are the same, and their positions are symmetrical, which facilitates processing and reduces stress concentration.

[0074] like Figure 3 As shown, in some embodiments of this application, multiple connectors 6 are provided, and the multiple connectors 6 are spaced apart along the second direction Y in the accommodating space 4 to divide the accommodating space 4 into multiple sub-accommodating spaces 41.

[0075] In this embodiment of the application, by arranging multiple connectors 6 at intervals along the second direction Y, the accommodating space 4 can be divided into multiple sub-accommodating spaces 41, thereby dividing the internal space of the battery pack into multiple regions. This not only makes it less likely that the cell group 3 in each sub-accommodating space 41 will affect the cell group 3 in the adjacent sub-accommodating space 41 when thermal runaway occurs, thus facilitating the thermal management of the battery pack, but also makes it easier to arrange the cell group 3 in the accommodating space 4 according to actual needs, thereby improving the applicability of the battery pack.

[0076] In specific applications, the number of connectors 6 can be set to 2, 3, 4, 5, etc., depending on the actual needs of the battery pack. Those skilled in the art can set it according to actual needs, and this application does not impose any restrictions on it.

[0077] It should be noted that the bottom of each connector 6 is welded to the base plate 11 through the second grooves 61 on both sides of the first direction X, and the end of each connector 6 along the second direction Y is welded to the side plate 12, thereby forming a stable connection structure.

[0078] Understandably, the connector 6 is positioned between the two sub-accommodating spaces 41, which can form a flame barrier for the battery cell group 3 in the adjacent sub-accommodating spaces 41; and the second groove 61 positioned on both sides of the connector 6 in the first direction X can form two welds respectively, thereby reducing the fatigue risk of the weld on one side.

[0079] like Figure 5 As shown, in some embodiments of this application, the width of the first groove 21 along the second direction Y is W1, and the width of the battery cell group 3 along the second direction Y is W2, satisfying: 0.4≤W1 / W2≤0.6.

[0080] In this embodiment of the application, by setting the ratio between the width W1 of the first groove 21 and the width W2 of the battery cell assembly 3 within a reasonable range, it is possible to ensure that the end beam 2 has sufficient contact surface to provide pre-tightening force to the battery cell assembly 3, while ensuring the length of the weld formed in the first groove 21, thereby ensuring the connection strength between the end beam 2 and the base plate 11.

[0081] It should be explained that when the ratio W1 / W2 between the width W1 of the first groove 21 and the width W2 of the cell assembly 3 is less than 0.4, that is, when the width W1 of the first groove 21 is too small, the first groove 21 can accommodate less solder, which means that the weld formed in the first groove 21 is shorter. This results in an insufficient connection area between the end beam 2 and the base plate 11, leading to insufficient connection strength between the end beam 2 and the base plate 11. On the other hand, when the ratio W1 / W2 between the width W1 of the first groove 21 and the width W2 of the cell assembly 3 is greater than 0.6, that is, when the width W1 of the first groove 21 is too large, the contact area between the end beam 2 and the cell assembly 3 is too small. This means that the end beam 2 cannot provide sufficient preload to the cell assembly 3, which may cause the cell assembly 3 to shift.

[0082] In specific applications, the ratio W1 / W2 between the width W1 of the first groove 21 and the width W2 of the cell assembly 3 can be set to any value or a range between two arbitrary values, such as 0.4, 0.42, 0.44, 0.46, 0.48, 0.5, 0.52, 0.54, 0.56, 0.58, 0.6.

[0083] Understandably, the width W1 of the first groove 21 along the second direction Y can be measured in practice as the distance between the two groove walls of the first groove 21 in the second direction Y; for example... Figure 6As shown, the width W2 of the battery cell assembly 3 along the second direction Y specifically refers to the width of a single battery cell assembly 3. In actual measurement, the distance between two opposite end faces of the battery cell assembly 3 in the second direction Y can be measured.

[0084] like Figure 5 As shown, in some embodiments of this application, the width W1 of the first groove 21 along the second direction Y satisfies: 72mm≤W1≤110mm.

[0085] In this embodiment of the application, by setting the width W1 of the first groove 21 along the second direction Y within a reasonable range, it is possible to ensure that the end beam 2 has sufficient contact surface to provide pre-tightening force to the battery cell assembly 3, while ensuring the length of the weld formed in the first groove 21, thereby ensuring the connection strength between the end beam 2 and the base plate 11.

[0086] It should be explained that when the width W1 of the first groove 21 along the second direction Y is less than 72mm, the first groove 21 can accommodate less solder, that is, the weld formed in the first groove 21 is shorter, which makes the connection area between the end beam 2 and the base plate 11 too small, resulting in insufficient connection strength between the end beam 2 and the base plate 11. On the other hand, when the width W1 of the first groove 21 along the second direction Y is greater than 110mm, the contact area between the end beam 2 and the battery cell assembly 3 is too small, which makes the end beam 2 unable to provide sufficient preload to the battery cell assembly 3, which makes the battery cell assembly 3 at risk of displacement.

[0087] In specific applications, the width W1 of the first groove 21 can be set to any value or a range between two arbitrary values, such as 72mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, 105mm, 110mm.

[0088] It should be noted that the width W1 of the first groove 21 needs to be determined based on the width W2 of a single cell assembly 3 and the overall length of the end beam 2 along the second direction Y. In the specific design, simulation calculations can be performed to ensure the pre-tightening force of the end beam 2 on the cell assembly 3 and the reliability of the connection between the end beam 2 and the base plate 11. Those skilled in the art can set it according to actual needs, and this application does not impose any restrictions on it.

[0089] like Figure 5 As shown, in some embodiments of this application, the depth of the first groove 21 along the first direction X is H1, and the thickness of the abutting portion 23 along the first direction X is H2, satisfying: 0.1≤H1 / H2≤0.4.

[0090] In this embodiment of the application, by setting the ratio H1 / H2 between the depth H1 of the first groove 21 along the first direction X and the thickness H2 of the abutment portion 23 along the first direction X within a reasonable range, on the one hand, the first groove 21 has enough space to accommodate the solder 5, and on the other hand, the overall strength of the abutment portion 23 can be guaranteed.

[0091] It needs to be explained that when the ratio H1 / H2 between the depth H1 of the first groove 21 along the first direction X and the thickness H2 of the abutment portion 23 along the first direction X is less than 0.1, that is, the depth H1 of the first groove 21 along the first direction X is too small, meaning the depth of the first groove 21 is insufficient, the first groove 21 does not have enough space to accommodate the solder 5, which causes the weld formed by the solder 5 after welding to protrude from the end beam 2, interfering with the battery cell assembly 3; and when the ratio H1 / H2 between the depth H1 of the first groove 21 along the first direction X and the thickness H2 of the abutment portion 23 along the first direction X is greater than 0.4, that is, the depth H1 of the first groove 21 along the first direction X is too large, meaning the first groove 21 is too deep, the first groove 21 occupies too much of the abutment portion 23 in the first direction X, causing the abutment portion 23 to form an approximate "gap" at the first groove 21, which not only reduces the strength of the abutment portion 23, but also causes stress concentration at the first groove 21.

[0092] In specific applications, the ratio H1 / H2 between the depth H1 of the first groove 21 along the first direction X and the thickness H2 of the abutment portion 23 along the first direction X can be set to any value or a range between two arbitrary values, such as 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4.

[0093] It should be explained that, in actual measurement, the depth H1 of the first groove 21 along the first direction X can be used to measure the vertical distance between the end face of the abutment part 23 facing the cell assembly 3 and the bottom of the first groove 21; the thickness H2 of the abutment part 23 along the first direction X can be used to measure the vertical distance between the end face of the support part 22 facing the cell assembly 3 and the end face of the abutment part 23 facing the cell assembly 3.

[0094] like Figure 5 As shown, in some embodiments of this application, the depth H1 of the first groove 21 along the first direction X satisfies: 2.6mm≤H1≤10mm.

[0095] In this embodiment of the application, by setting the depth H1 of the first groove 21 along the first direction X within a reasonable range, the first groove 21 has enough space to accommodate the solder 5, and the overall strength of the abutment portion 23 can be guaranteed.

[0096] It needs to be explained that when the depth H1 of the first groove 21 along the first direction X is less than 2.6 mm, the first groove 21 does not have enough space to accommodate the solder 5, which causes the weld formed by the solder 5 after welding to protrude from the end beam 2 and interfere with the battery cell assembly 3; while when the depth H1 of the first groove 21 along the first direction X is greater than 10 mm, the first groove 21 occupies too much of the abutment portion 23 in the first direction X, which not only reduces the strength of the abutment portion 23, but also causes stress concentration at the first groove 21.

[0097] In specific applications, the depth H1 of the first groove 21 along the first direction X can be set to any value or a range between two arbitrary values, such as 2.6mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm.

[0098] It should be explained that, when designing the depth H1 of the first groove 21 along the first direction X, it is necessary to consider the actual height of the weld formed when the end beam 2 and the base plate 11 are welded, so that it can accommodate the welding material.

[0099] like Figure 5 As shown, in some embodiments of this application, the width of each first groove 21 along the second direction Y is W1, the number of first grooves 21 in the end beam 2 is n, and the length of the end beam 2 along the second direction Y is L, satisfying: 0.45≤(n×W1) / L≤0.54.

[0100] In this embodiment, by setting the ratio (n×W1) / L between the product of the number n of the first grooves 21 in each end beam 2 and the width W1 of each first groove 21 and the length L of the end beam 2 along the second direction Y, the solder 5 during welding can be contained in the first grooves 21, forming multiple connection areas between the end beam 2 and the base plate 11 to ensure connection strength; at the same time, the overall strength of the end beam 2 is guaranteed, and the risk of stress concentration is reduced.

[0101] It needs to be explained that when the ratio (n×W1) / L between the product of the number n of the first grooves 21 in each end beam 2 and the width W1 of each first groove 21 and the length L of the end beam 2 along the second direction Y is less than 0.45, that is, when the sum of the widths W1 of all the first grooves 21 in each end beam 2 is too small, the width W1 of each first groove 21 is too small, so that the first groove 21 does not have enough space to accommodate the solder 5 during welding; and when the ratio (n×W1) / L between the product of the number n of the first grooves 21 in each end beam 2 and the width W1 of each first groove 21 and the length L of the end beam 2 along the second direction Y is greater than 0.54, that is, when the sum of the widths W1 of all the first grooves 21 in each end beam 2 is too large, the first grooves 21 in each end beam 2 occupy too much space, which reduces the overall strength of the end beam 2 and makes it easy for stress concentration to occur.

[0102] In specific applications, the ratio (n×W1) / L between the product of the number n of the first grooves 21 in each end beam 2 and the width W1 of each first groove 21 and the length L of the end beam 2 along the second direction Y can be set to any value such as 0.45, 0.48, 0.5, 0.52, 0.54 or a range between two arbitrary values.

[0103] It should be noted that, in actual measurement, the length L of the end beam 2 along the second direction Y can be measured by measuring the vertical distance between the end faces of the two side plates 12 facing the cell assembly 3.

[0104] For example, such as Figure 5 As shown, each end beam 2 is provided with 4 first grooves 21. The length L of the end beam 2 along the second direction Y is 750mm, and the width W1 of each first groove 21 is 100mm. Then, it can be calculated that (4×100mm) / 750mm=0.53, which meets the above ratio range.

[0105] In some embodiments of this application, an electrical device is also proposed, including a battery pack as described in any of the above embodiments, the battery pack being used to supply power to the electrical device.

[0106] In the embodiments of this application, the electrical equipment includes the battery pack described in any of the above embodiments, thereby the electrical equipment has the beneficial effects of any of the above embodiments, which will not be repeated here.

[0107] In specific applications, electrical equipment can be electric vehicles, such as pure electric vehicles, hybrid electric vehicles, electric motorcycles, electric ships, and aircraft; it can also be energy storage systems, such as energy storage cabinets and energy storage power stations; or it can be industrial equipment, such as electric excavators, electric loaders, electric forklifts, and automated guided vehicles.

[0108] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0109] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery pack, characterized by, The battery pack comprises a substrate (1), an end beam (2) and a battery cell group (3), the battery pack has a first direction (X) and a second direction (Y) perpendicular to each other, the end beam (2) is arranged on both sides of the substrate (1) along the first direction (X), the substrate (1) and the end beam (2) form an accommodating space (4), the battery cell group (3) is arranged in the accommodating space (4), and the battery cell group (3) abuts against the end beam (2) along the first direction (X); one side of the end beam (2) facing the battery cell group (3) is provided with a first groove (21), the end beam (2) is welded with the substrate (1) at the first groove (21), and the first groove (21) is used for accommodating solder (5). The end beam (2) comprises a supporting part (22) and an abutting part (23) connected with each other, the first groove (21) is arranged on one side of the abutting part (23) facing the battery cell group (3), the abutting part (23) is welded with the substrate (1) at the first groove (21), and the supporting part (22) is arranged on one side of the abutting part (23) away from the battery cell group (3); the abutting part (23) abuts against the battery cell group (3) along the first direction (X), the abutting part (23) is provided with a connecting hole (231), and the battery cell group (3) is connected with the connecting hole (231). The substrate (1) comprises a bottom plate (11) and a side plate (12), the end beam (2) is arranged on both sides of the bottom plate (11) along the first direction (X), and the end beam (2) is welded with the bottom plate (11) at the first groove (21); the side plate (12) is arranged on both sides of the bottom plate (11) along the second direction (Y) and is welded with the bottom plate (11); and the bottom plate (11), the side plate (12) and the end beam (2) form the accommodating space (4). The width of the first groove (21) along the second direction (Y) is W1, the width of the battery cell group (3) along the second direction (Y) is W2, and 0.4≤W1 / W2≤0.6 is met; wherein, 72mm≤W1≤110mm; The number of the first grooves (21) in the end beam (2) is n, the length of the end beam (2) along the second direction (Y) is L mm, and 0.45≤(n×W1) / L≤0.54 is met. A plurality of battery cell groups (3) are arranged along the second direction (Y), and the end beam (2) is provided with the first groove (21) at a position corresponding to each battery cell group (3).

2. The battery pack of claim 1, wherein, The projection of the first groove (21) along the first direction (X) falls within the projection of the battery cell group (3) along the first direction (X).

3. The battery pack of claim 1, wherein, ​ 4. The battery pack of any one of claims 1-3, wherein, The battery pack further comprises a connecting piece (6) connected with the base plate (1), the connecting piece (6) is arranged in the accommodating space (4) to divide the accommodating space (4) into at least two sub-accommodating spaces (41), and the battery cell group (3) is arranged in each sub-accommodating space (41); In the first direction (X), one end of the battery cell group (3) abuts against the end beam (2), and the other end of the battery cell group (3) abuts against the connecting piece (6), the connecting piece (6) is provided with a second groove (61) on the opposite sides in the first direction (X), the connecting piece (6) is welded with the base plate (1) at the second groove (61), and the second groove (61) is used for accommodating solder (5).

5. The battery pack of claim 4, wherein, The projection of the first groove (21) in the first direction (X) at least partially overlaps the projection of the second groove (61) in the first direction (X).

6. The battery pack of claim 4, wherein, The connecting piece (6) is provided in plurality, and the plurality of connecting pieces (6) are arranged in the accommodating space (4) in the second direction (Y) to divide the accommodating space (4) into a plurality of sub-accommodating spaces (41).

7. The battery pack of claim 1, wherein, The depth of the first groove (21) in the first direction (X) is H1, and the thickness of the abutting portion (23) in the first direction (X) is H2, and 0.1≤H1 / H2≤0.4 is satisfied.

8. The battery pack of claim 1, wherein, The depth H1 of the first groove (21) in the first direction (X) satisfies 2.6mm≤H1≤10mm.

9. An electric device, characterized by Comprise: The battery pack of any one of claims 1-8 is used to power the electrical equipment.

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