A battery bus, a battery pack and a battery pack mounting method

Abstract

The embodiment of the application provides a battery busbar, a battery pack and a battery pack mounting method. The battery busbar comprises: a plurality of layers of flexible conductive sheets connected in layers, the plurality of layers of flexible conductive sheets comprising a first connecting section, a second connecting section and a buffer section, the buffer section being connected between the first connecting section and the second connecting section and protruding from the first connecting section and the second connecting section, wherein the buffer section comprises a plurality of layers of arc sections, and the curvature of at least part of the arc sections is different. In the embodiment of the application, when the battery module is mounted in the shell, the arc-shaped buffer section can abut against the first peripheral wall of the shell, the arc-shaped buffer section can absorb the force generated by the thermal expansion deformation of the battery module in the working process through its own deformation, the force is prevented from being transmitted to the welding points of the first connecting section and the second connecting section and the side tab of the battery cell, and the connection reliability of the battery pack is ensured.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery busbar, a battery pack, and a battery pack installation method. Background Technology

[0002] Currently, CTP (cell-to-pack) elongated battery integration adopts a large CTP module integration solution. This solution involves first fabricating the battery cells into large modules and then assembling them into a casing. This results in issues such as structural components for module positioning and installation, as well as installation gaps within the battery casing. These module structural components increase the weight and cost of battery integration, while the installation gaps reduce the volume utilization rate of the integrated battery. Summary of the Invention

[0003] The purpose of this application is to provide a battery busbar, a battery pack, and a battery pack installation method to solve the technical problems in the related art where module structural components increase the weight and cost of battery integration, and the installation gap of the module reduces the volume utilization rate of battery integration.

[0004] This application provides a battery busbar, including: a multilayer flexible conductive sheet stacked together, the multilayer flexible conductive sheet including a first connecting segment, a second connecting segment and a buffer segment, the buffer segment being connected between the first connecting segment and the second connecting segment and protruding from the first connecting segment and the second connecting segment, wherein the buffer segment includes multiple arc segments, at least some of the arc segments having different curvatures.

[0005] In this embodiment of the application, when the battery module is installed in the housing, the arc-shaped buffer section can abut against the first peripheral wall of the housing. The arc-shaped buffer section can absorb the force generated by the thermal expansion deformation during the operation of the battery module through its own deformation, preventing the force from being transmitted to the welding point between the first connecting section and the second connecting section and the electrode tab on the side of the cell, thus ensuring the connection reliability of the battery pack.

[0006] In some embodiments, the curvature of the multi-layered arc segments gradually decreases from the outside to the inside in the radial direction.

[0007] In this embodiment, the outermost arc segment, which is also the one closest to the first peripheral wall of the shell, has the largest curvature. This means that the arc segment closer to the first peripheral wall has a larger deformation range, greater flexibility, and more significant absorption of external forces. This ensures that external forces are not transmitted to the welding points between the first and second connecting segments and the electrode tabs on the side of the battery cell, making it more reliable.

[0008] In some embodiments, the first connecting segment and the second connecting segment are respectively formed as multi-layer flat segments.

[0009] In this embodiment, the first connecting segment and the second connecting segment are respectively formed by multiple layers of flexible conductive sheets to form a flat segment stacked together, which has a plane for connecting the electrode tab. This facilitates welding with the electrode tab on the side of the battery cell, making the connection more reliable.

[0010] In some embodiments, the multilayer flexible conductive sheets are connected by polymer diffusion welding.

[0011] In this embodiment, polymer diffusion welding is used to ensure reliable connection of each layer of aluminum foil.

[0012] In some embodiments, the welding points of the multilayer flexible conductive sheet are located on the flat section.

[0013] In this embodiment, the welding point avoids the arc-shaped buffer section. This way, when the buffer section absorbs external force deformation, the stress will not be concentrated in the buffer section, and it will hardly affect the connection of the welding points of each layer of flat section, thus preventing the arc-shaped buffer section from breaking when it deforms.

[0014] This application also provides a battery pack, including: a housing; a battery module disposed within the housing, the battery module including a plurality of battery cells, each battery cell having a tab on its side; and a battery bus as described in any of the above embodiments, wherein the first connecting section and the second connecting section of the battery bus are respectively connected to the tabs of two adjacent battery cells, so that the plurality of battery cells are connected in series or in parallel.

[0015] In this embodiment of the battery pack, the side tabs of each cell are connected by a battery busbar. The tabs can be welded first, and then the battery module can be installed into the housing. No side plate structure is required. The arc-shaped buffer section of the battery busbar can absorb the force generated by the thermal expansion of the battery.

[0016] In some embodiments, the battery module further includes: end plates, which are fixed to opposite ends of the battery cell by buffer adhesive.

[0017] In this embodiment of the application, during installation, the individual cells can be glued together first, and then end plates can be glued to both ends of the cells using buffer adhesive. The end plates can effectively protect the battery module clamping installation. When the battery module is clamped and compressed into the housing, it compresses the foam in the battery module, generating a buffering effect.

[0018] In some embodiments, the buffer section of the battery bus abuts against a first peripheral wall of the housing, the first peripheral wall being opposite to the side of the battery cell.

[0019] In this embodiment of the application, when the battery pack undergoes thermal expansion and deformation, the buffer section can form a compression interference with the first peripheral wall. The buffer section generates deformation to absorb the compression force and prevent the compression force from being transmitted to the connection point of the first connecting section and the second connecting section.

[0020] In some embodiments, the end plates at opposite ends of the battery cell abut against the second peripheral wall and crossbeam of the housing, wherein the second peripheral wall and crossbeam are respectively opposite to the ends of the battery cell, and clearance grooves are provided on the second peripheral wall and the crossbeam.

[0021] In this embodiment, the clearance groove is used to avoid the clamping tool, so that the clamping tool can be removed when the battery module is installed in the housing. The battery module can be squeezed between the second peripheral wall and the crossbeam at both ends of the cell. Compared with the traditional method of fixing it to the housing with fasteners, the entire battery pack is more compact and has a higher space utilization rate.

[0022] In some embodiments, the housing further includes longitudinal beams, which divide the housing into multiple receiving spaces, in which the battery module is disposed, wherein the height of the longitudinal beams is lower than the height of the battery busbar.

[0023] In this embodiment, the height of the longitudinal beam is lower than the height of the battery busbar, thus avoiding interference from the battery module busbar.

[0024] This application also provides a battery pack installation method, applied to the battery pack described in any of the above embodiments. The method includes: pasting multiple battery cells together and pasting end plates at both ends of the battery cells with buffer adhesive; welding the tabs on the sides of the multiple battery cells through the battery busbar to form a battery module connected in series or in parallel; installing the battery module in the housing, such that the buffer section of the battery busbar abuts against the first peripheral wall of the housing, and the end plates at both ends of the battery cells abut against the second peripheral wall and the crossbeam of the housing.

[0025] In this embodiment, by first welding the battery cell tabs through the battery busbar and then squeezing the entire battery module into the housing, the structure of the battery busbar can absorb the force generated by the thermal expansion of the battery, and the space utilization is improved by squeezing it in. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a battery busbar provided in an embodiment of this application; Figure 2This is a schematic diagram of a battery busbar structure from another perspective, provided in an embodiment of this application. Figure 3 This is a schematic diagram of a battery pack structure provided in an embodiment of this application; Figure 4 This is an exploded view of a battery pack provided in an embodiment of this application; Figure 5 This is a schematic diagram of a partial structure of a battery pack provided in an embodiment of this application; Figure 6 This is a schematic diagram of the battery module structure provided in an embodiment of this application; Figure 7 This is a flowchart illustrating a battery pack installation method provided in an embodiment of this application. Detailed Implementation

[0028] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0029] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0030] Please refer to Figure 1 , Figure 2 and Figure 6 , Figure 1 This is a schematic diagram of a battery busbar provided in an embodiment of this application; Figure 2 This is a schematic diagram of a battery busbar structure from another perspective, provided in an embodiment of this application. Figure 6 This is a schematic diagram of the battery module structure provided in an embodiment of this application.

[0031] This application provides a battery busbar, including: a multilayer flexible conductive sheet 10 stacked and connected, the multilayer flexible conductive sheet 10 including a first connecting segment 11, a second connecting segment 12 and a buffer segment 13, the buffer segment 13 being connected between the first connecting segment 11 and the second connecting segment 12 and protruding from the first connecting segment 11 and the second connecting segment 12, wherein the buffer segment 13 includes multiple arc segments, at least some of the arc segments having different curvatures.

[0032] The multilayer flexible conductive sheet 10 has a sheet-like structure and is used to connect the tabs between battery cells, allowing multiple cells to be connected in series or parallel. The first connecting segment 11 of the flexible conductive sheet 10 can be welded to one tab on the side of a battery cell (e.g., the positive tab), and the second connecting segment 12 can also be welded to another tab on the side of a battery cell (e.g., the negative tab). A buffer segment 13 connects between the first connecting segment 11 and the second connecting segment 12, and protrudes beyond the first and second connecting segments 11 and 12, so that the entire multilayer flexible conductive sheet 10, when stacked together, forms an arch or "Ω" shape. When the battery module is installed in the housing 20, the arc-shaped buffer segment 13 can abut against the first peripheral wall 24 of the housing 20. The arc-shaped buffer segment 13, through its own deformation, can absorb the force generated by the thermal expansion deformation during the operation of the battery module, preventing this force from being transmitted to the welding points of the first and second connecting segments 11 and 12 with the tabs on the side of the battery cells, ensuring the reliability of the battery pack connection. For example, the multilayer flexible conductive sheet 10 is an aluminum foil sheet and / or a copper foil sheet. For example, the multilayer flexible conductive sheet 10 can be made of multiple layers of aluminum foil stacked together, or multiple layers of copper foil stacked together, or aluminum foil and copper foil stacked together.

[0033] In some embodiments, the curvature of the multi-layered arc segments formed by the buffer section 13 gradually decreases from the outside to the inside in the radial direction. That is, the outermost arc segment, which is also the one closest to the first peripheral wall 24 of the housing 20, has the largest curvature. In this way, the arc segment closer to the first peripheral wall 24 has a larger deformation range, greater flexibility, and more obvious absorption of external force, ensuring that the external force will not be transmitted to the welding point between the first connecting section 11 and the second connecting section 12 and the electrode tab on the side of the battery cell, which is more reliable.

[0034] In some embodiments, the first connecting segment 11 and the second connecting segment 12 are respectively formed as multi-layer flat segments. The first connecting segment 11 and the second connecting segment 12 are respectively formed by multi-layer flexible conductive sheets 10 stacked together as flat segments, having a plane for connecting tabs, which facilitates welding to the tabs on the side of the battery cell and makes the connection more reliable.

[0035] In some embodiments, the multilayer flexible conductive sheet 10 is connected by polymer diffusion welding. Since the multilayer flexible conductive sheet 10 is thin, such as an aluminum foil sheet, polymer diffusion welding ensures reliable connection between the aluminum foil layers.

[0036] Alternatively, the welding points of the multilayer flexible conductive sheet are located in the aforementioned flat section, that is, the welding points avoid the arc-shaped buffer section 13. In this way, when the buffer section 13 absorbs external force deformation, the stress will not be concentrated in the buffer section 13, and it will hardly affect the connection of the welding points of each layer of flat section, thus preventing the arc-shaped buffer section 13 from breaking when it deforms.

[0037] This application also provides a battery pack, such as... Figures 3-6 As shown, Figure 3 This is a schematic diagram of a battery pack structure provided in an embodiment of this application; Figure 4 This is an exploded view of a battery pack provided in an embodiment of this application; Figure 5 This is a partial structural diagram of a battery pack provided in an embodiment of this application. The battery pack includes: a housing 20, a battery module, and a battery busbar as described in any of the above embodiments.

[0038] The battery module is disposed inside the housing 20. The battery module includes multiple battery cells 30. The battery cells 30 have tabs on their sides. The first connecting section 11 and the second connecting section 12 of the battery busbar are respectively connected to the tabs of two adjacent battery cells, so that the multiple battery cells are connected in series or in parallel.

[0039] For example, multiple battery cells 30 can be fixed together with double-sided tape, and then the positive electrode tab on the side of one of the two adjacent battery cells is connected by the first connecting segment 11, and the negative electrode tab on the side of the other of the two adjacent battery cells is connected by the second connecting segment 12, so that the multiple battery cells 30 are connected in series.

[0040] In this embodiment of the battery pack, the side tabs of each cell 30 are connected by a battery busbar. The tabs can be welded first, and then the battery module can be installed into the housing 20. No side plate structure is required. The arc-shaped buffer section of the battery busbar can absorb the force generated by the thermal expansion of the battery.

[0041] In some embodiments, the battery module further includes an end plate 40, which is fixed to the end of the cell 30 by a buffer adhesive 50.

[0042] The buffer adhesive serves to absorb shock and provide thermal insulation. For example, the buffer adhesive can be foam, which can be designed as a long strip and bonded to the end of the battery with adhesive. If thermal insulation is required, it can be replaced by a combination of aerogel and other thermal insulation materials, foam, and adhesive. To increase structural strength, the bonding area of ​​the foam can be increased, while still meeting the expansion forces and space requirements during battery cycling. The end plate 40 serves as protection when clamping the battery module; its height can be no less than 80% of the cell height, and its width should be sufficient to prevent the busbars on both sides from protruding after welding.

[0043] During installation, the individual battery cells can be glued together first. Then, end plates are glued to both ends of the cells using cushioning adhesive. The end plates 40 effectively protect the battery module during clamping and installation. When the battery cell module is clamped and compressed into the housing 20, the foam in the battery module is compressed, creating a cushioning effect. The clamping pressure depends on the size of the compression into the housing and the structural holding force of the battery module. The compressed battery module can be 8-12mm smaller than the housing installation size to avoid impact to the housing during compression. During the transfer process after the tooling clamps and compresses the battery module, it ensures that there is no displacement between the cells. Therefore, the connection strength can be increased between the cells and between the cells and the end plates using foam adhesive.

[0044] In some embodiments, the buffer section 13 of the battery busbar may abut against the housing 20. For example, it may abut against the first peripheral wall 24 of the housing 20, which is opposite to the side of the battery cell 30. When the battery pack undergoes thermal expansion and deformation, the buffer section 13 may form a compression interference with the first peripheral wall 24. The buffer section 13 deforms to absorb the compression force and prevents the compression force from being transmitted to the connection point of the first connecting section 11 and the second connecting section 12.

[0045] In some embodiments, the end plates 40 of the battery module abut against the housing 20. For example, the end plates 40 at both ends of the battery module can abut against the second peripheral wall and the crossbeam 21. The second peripheral wall and the crossbeam 21 are opposite to the ends of the battery cell 30, and the second peripheral wall has a clearance groove 23. The clearance groove 23 is used to avoid clamping tools, allowing the clamping tools to be removed when the battery module is installed in the housing 20. The battery module can be compressed between the opposing second peripheral wall and the crossbeam 21 at both ends of the battery cell 30. Compared to the traditional method of fixing the battery to the housing with fasteners, the entire battery pack is more compact and has a higher space utilization rate.

[0046] In some embodiments, the housing 20 includes a crossbeam 21 and a longitudinal beam 22, which divide the housing 20 into multiple receiving spaces, in which battery modules are disposed, wherein the height of the longitudinal beam 22 is lower than the height of the battery busbar.

[0047] The crossbeam 21 is used to compress the end plate of the battery module to make the compressive force uniform, and its height can be no less than 80% of the cell height; the longitudinal beam 22 is lower than the height of the battery busbar to avoid interference with the battery module busbar, for example, it is lower than the busbar height and no less than 5mm.

[0048] This application also provides a battery pack installation method, applied to the battery pack described in any of the above embodiments, the method including: step S11, step S12 and step S13.

[0049] In step S11, multiple battery cells are glued together, and end plates are glued to both ends of the battery cells using buffer adhesive.

[0050] Multiple battery cells can be bonded together with two adjacent sides using double-sided tape to form multiple battery cell groups. Then, end plates 40 are bonded to both ends of the multiple battery cell groups using double-sided tape, so that the end plates 40 can be clamped with a clamping tool. At the same time, the double-sided tape also protects the battery cells.

[0051] In step S12, the tabs on the sides of multiple battery cells are welded together through a battery busbar to form a battery module connected in series or in parallel.

[0052] The first connecting section 11 of the arched battery busbar can be connected to the positive electrode tab on the side of one of the two adjacent cells by welding, and the second connecting section 12 can be connected to the negative electrode tab on the side of the other of the two adjacent cells by welding, so that multiple cells 30 are connected in series.

[0053] In step S13, the battery module is installed in the housing 20, with the buffer section of the battery busbar abutting against the first peripheral wall 24 of the housing 20, and the end plates at both ends of the battery cell 30 abutting against the second peripheral wall and crossbeam of the housing 20. The entire battery module is pressed and fixed in the housing 20 by the second peripheral wall and crossbeam of the housing 20. Compared with the traditional method of fixing it to the housing with fasteners, the entire battery pack is more compact and has a higher space utilization rate.

[0054] In this embodiment, by first welding the battery cell tabs through the battery busbar and then squeezing the entire battery module into the housing 20, the structure of the battery busbar can absorb the force generated by the thermal expansion of the battery. On the other hand, the space utilization is improved by squeezing it in.

[0055] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0056] In addition, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0057] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0058] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0059] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0060] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A battery pack, characterized in that, include: The shell, including the first peripheral wall; A battery module is disposed within the housing. The battery module includes multiple battery cells and end plates. Each battery cell has tabs on its side, and the end plates are fixed to opposite ends of the battery cells using cushioning adhesive. A battery busbar includes multiple layers of flexible conductive sheets stacked together. The multiple layers of flexible conductive sheets include a first connecting segment, a second connecting segment, and a buffer segment. The buffer segment is connected between the first connecting segment and the second connecting segment and protrudes from the first connecting segment and the second connecting segment. The buffer segment includes multiple arc segments, at least some of which have different curvatures. The curvature of the multiple arc segments formed by the buffer segment gradually decreases from the outside to the inside in the radial direction, with the arc segment closest to the first peripheral wall having the largest curvature. The first connecting section and the second connecting section of the battery busbar are respectively connected to the tabs of two adjacent battery cells, so that multiple battery cells are connected in series or in parallel. The buffer section of the battery busbar abuts against the first peripheral wall of the housing, and the first peripheral wall is opposite to the side of the battery cell.

2. The battery pack according to claim 1, characterized in that, include: The curvature of the multi-layered arc segments gradually decreases from the outside to the inside in the radial direction.

3. The battery pack according to claim 1, characterized in that, The first connecting segment and the second connecting segment are each formed as a multi-layered flat segment.

4. The battery pack according to claim 3, characterized in that, The multilayer flexible conductive sheets are connected by polymer diffusion welding.

5. The battery pack according to claim 4, characterized in that, The welding points of the multilayer flexible conductive sheet are located in the flat section.

6. The battery pack according to claim 1, characterized in that, The multilayer flexible conductive sheet is an aluminum foil sheet and / or a copper foil sheet.

7. The battery pack according to claim 1, characterized in that, The end plates at opposite ends of the battery cell abut against the second peripheral wall and the crossbeam of the housing, wherein the second peripheral wall and the crossbeam are respectively opposite to the ends of the battery cell, and clearance grooves are provided on the second peripheral wall and the crossbeam.

8. The battery pack according to claim 7, characterized in that, The housing also includes longitudinal beams, which divide the housing into multiple receiving spaces. The battery module is disposed in the corresponding receiving space, wherein the height of the longitudinal beams is lower than the height of the battery busbar.

9. A battery pack installation method, characterized in that, Applied to a battery pack as described in any one of claims 1-8, the method comprises: Multiple battery cells are glued together, and end plates are glued to both ends of each battery cell using buffer adhesive. Multiple battery cells are connected in series or parallel by welding the tabs on the side of the battery cells through the battery busbar. The battery module is installed in the housing, with the buffer section of the battery bus abutting against the first peripheral wall of the housing, and the end plates at both ends of the battery cell abutting against the second peripheral wall and the crossbeam of the housing.

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