Battery pack and method of assembling the same

Abstract

This application discloses a battery pack and its assembly method. The battery pack includes a housing, individual battery cells, and a flexible layer. An mounting cavity is formed within the housing, extending through the housing in a first direction. Reinforcing members are provided on the end faces of opposite ends of the housing in a second direction, extending along a third direction. At least two individual battery cells are disposed within the mounting cavity and stacked along the second direction within the mounting cavity. The flexible layer is disposed within the mounting cavity and located between the individual battery cells and the housing wall. Each pair in the first, second, and third directions is angled. This allows the housing to meet the core requirements of lightweight design, reliable expansion force control throughout its entire life cycle, and efficient thermal management.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery pack and its assembly method. Background Technology

[0002] In related technologies, energy storage battery pack integration solutions mainly include module integration solutions and cell-to-pack (CTP) solutions. Module integration solutions require pre-forming battery modules and then inserting them into the battery pack, resulting in low assembly efficiency and poor weight reduction. CTP solutions manage expansion forces by using expansion beams within the battery pack, but the expansion force transmission path is unreasonable, making core components prone to failure and posing high safety risks. Summary of the Invention

[0003] This application provides a battery pack and its assembly method, which achieves reliable control of the expansion force of a single cell throughout its entire life cycle by forming a dual expansion force management system of rigid structural constraint and elastic material buffer through the reinforcement and flexible layer. This solves at least part of the above-mentioned technical problems.

[0004] To achieve the above objectives, according to a first aspect of this application, a battery pack is provided, comprising: The housing has an internal mounting cavity that extends through the housing in a first direction. The housing has reinforcing members on its opposite end faces in a second direction, and the reinforcing members extend in a third direction. A single battery cell is disposed within the mounting cavity, wherein at least two single battery cells are provided, and the at least two single battery cells are stacked along the second direction within the mounting cavity; A flexible layer is disposed within the mounting cavity, and the flexible layer is located between the individual battery cell and the casing wall. Wherein, each of the first direction, the second direction and the third direction is set at an angle.

[0005] This enables the enclosure to meet the core requirements of lightweight design, reliable control of expansion force throughout the entire life cycle, and efficient thermal management.

[0006] Optionally, along the third direction, there is a first gap between the individual battery cell and the casing wall, the first gap being configured to accommodate at least a portion of the flexible layer, wherein the width of the first gap is D1, satisfying: 4 mm ≤ D1 ≤ 10 mm.

[0007] This ensures that after the foam is injected into the first gap, it can be evenly filled between the individual battery cell and the box wall to form a continuous buffer filling layer. It can also adapt to the thickness expansion of the individual battery cell throughout its entire life cycle, preventing the individual battery cell from directly squeezing the side wall of the box after expansion. At the same time, it provides process tolerance gaps for stacking and assembling individual battery cells, reducing the assembly difficulty of individual battery cells into the box.

[0008] Optionally, along the second direction, there is a second gap between the individual battery cell and the casing wall, the second gap being configured to accommodate at least a portion of the flexible layer, wherein the width of the second gap is D2, satisfying: 5 mm ≤ D1 ≤ 25 mm.

[0009] Therefore, it can adapt to the dimensional tolerances of stacked individual cells, reduce the assembly difficulty of individual cells into the box, and at the same time, it can serve as a filling space for expanding foam to achieve insulation protection and buffering of individual cells, and provide installation space for the high-voltage connection structure at the end.

[0010] Optionally, along the second direction, there is a third gap between each pair of adjacent individual cells, the third gap being configured to accommodate a buffer pad, wherein the width of the third gap is D3, satisfying: 1 mm ≤ D3 ≤ 6 mm.

[0011] This achieves thermal isolation between two adjacent individual cells, preventing the thermal spread of heat from individual cells after thermal runaway, and absorbing the expansion force of individual cells during charge and discharge cycles.

[0012] Optionally, the battery pack further includes: A liquid cooling plate is detachably connected to the bottom of the housing and seals one side of the mounting cavity.

[0013] This results in a shorter heat transfer path between the individual battery cell and the liquid cooling plate, and a lower contact thermal resistance.

[0014] Optionally, the battery pack further includes: An insulating film is disposed between the liquid cooling plate and the individual battery cell.

[0015] Therefore, an insulating film can be attached to the bottom of the individual cell for insulation protection, without any other structural obstruction, providing an unobstructed path for direct bonding and heat transfer between the individual cell and the liquid cooling plate.

[0016] Optionally, along the second direction, the insulating film includes a first fold portion protruding from the housing, the first fold portion being configured to adhere to the outer surface of the housing after folding, the width of the first fold portion being D4, satisfying: 5 mm ≤ D4 ≤ 10 mm; and / or, along the third direction, the insulating film includes a second fold portion protruding from the housing, the second fold portion being configured to adhere to the outer surface of the housing after folding, the width of the second fold portion being D5, satisfying: 5 mm ≤ D5 ≤ 10 mm.

[0017] This ensures that after the bottom surface of the individual battery cell is attached to the insulating film, it can achieve unobstructed and complete bonding with the liquid cooling plate, avoiding interference with the enclosure structure. It also ensures that the insulating film is applied flat and without wrinkles, while preventing the bottom of the individual battery cell from rubbing against the enclosure during hoisting and assembly, thus avoiding damage to the casing of the individual battery cell.

[0018] Optionally, the battery pack further includes: The CCS assembly is located inside the housing and is connected to the individual battery cell; Wherein, along the third direction, the distance between the side of the single cell and the side of the CCS assembly is D6, which satisfies: 30 mm ≤ D6 ≤ 80 mm.

[0019] This reduces the amount of materials needed for CCS components, thus lowering costs.

[0020] Optionally, along the first direction, the distance between the top surface of the CCS component and the top surface of the housing is D7, satisfying: 5 mm ≤ D7 ≤ 30 mm.

[0021] This ensures sufficient electrical clearance and creepage distance between the CCS components and the enclosure cover, guaranteeing absolute thermal safety.

[0022] Optionally, the CCS assembly includes a bracket, an aluminum busbar, and an FPC acquisition board. The aluminum busbar and the FPC acquisition board are both connected to the bracket. The aluminum busbar is electrically connected to the FPC acquisition board. The aluminum busbar is configured to be welded to the terminal post of the individual battery cell.

[0023] This enables real-time acquisition of all parameters of a single battery cell, eliminating the problem of messy wiring.

[0024] Optionally, the reinforcing member is hollow inside, and its longitudinal section is set to one of polygon, circle, or ellipse.

[0025] This results in the reinforcement having a large moment of inertia.

[0026] Optionally, the housing is a one-piece structural component.

[0027] This results in a simpler process for machining the enclosure, lower mold costs, and greater adaptability for mass production.

[0028] Optionally, the housing is further connected to mounting platforms at opposite ends in the second direction, the mounting platforms being configured to connect to the output aluminum busbars of the individual battery cells.

[0029] This allows for an integrated design of the high-voltage output structure, eliminating the need for additional aluminum busbar fixing brackets and reducing the number of components.

[0030] Optionally, the housing has a lifting hole, and the outer surface of the housing has a flange circumferentially disposed around the lifting hole.

[0031] This significantly improves the strength of the hoisting structure, meeting the stress requirements for the overall hoisting of the box after the foam has cured.

[0032] Optionally, the reinforcing member is provided as at least two, and the at least two reinforcing members are spaced apart along the first direction.

[0033] Therefore, by using at least two reinforcing components to jointly resist the expansion force of a single battery cell, the enclosure can reliably control the expansion force of a single battery cell throughout its entire life cycle.

[0034] Optionally, the single cell has an axis parallel to the third direction, and the reinforcing member is provided in two parts, namely a first reinforcing member and a second reinforcing member, wherein the first reinforcing member and the second reinforcing member are located on opposite sides of the axis.

[0035] This allows the first and second reinforcing members to respectively bear the expansion force near the top and the expansion force near the bottom of the individual battery cell.

[0036] Optionally, the first reinforcing member is located above the second reinforcing member, and along the first direction, the distance between the first reinforcing member and the axis is D8, and the distance between the second reinforcing member and the axis is D9, satisfying: D8 > D9.

[0037] This allows the second reinforcing member to be closer to the expansion concentration area, thus better resisting the expansion and deformation of the individual battery cell.

[0038] Optionally, the thickness of the reinforcing member is D10, satisfying: 1 mm ≤ D10 ≤ 2 mm.

[0039] This ensures that the reinforcing components have good strength to resist the expansion force of individual battery cells, while also ensuring a lighter overall weight.

[0040] According to a second aspect of this application, a method for assembling a battery pack is provided, applicable to the battery pack as described above, the assembly method comprising: A tooling is provided on which a membrane material is laid, wherein the membrane material includes an adhesive backing layer and a release film layer, and the release film layer is adhered to the tooling; Place the box body into the tooling; At least two of the individual battery cells are stacked in the housing along the second direction, and at least two of the individual battery cells are bonded to the adhesive layer. Inject expanding foam into the box; After the foam has cured, the CCS assembly is hoisted onto the top of the individual battery cell, and the aluminum busbar of the CCS assembly is welded to the terminal post of the individual battery cell to form an intermediate component. The intermediate component is hoisted onto the liquid cooling plate, and the housing and the liquid cooling plate are connected using fasteners.

[0041] As a result, the three core processes of stacking, potting and curing, and insulation mounting of individual battery cells can be integrated into the same workstation, reducing the production cycle by more than 50%, significantly reducing the types of materials and turnover, and lowering production line investment and management costs.

[0042] In the battery pack of this application embodiment, a mounting cavity extending through the housing in a first direction is provided within the housing. After the individual battery cells are placed in the mounting cavity, their bottoms are exposed without structural obstruction, providing a basis for direct heat transfer between the individual battery cells and the liquid cooling plate, thus shortening the heat transfer path and reducing contact thermal resistance. Reinforcing members are provided at the end faces of opposite ends in a second direction of the housing. These reinforcing members bear the full-cycle expansion force constraint of the individual battery cells from the initial stage to the end of their lifespan, eliminating the need for additional expansion beams. The flexible layer allows all battery cells to form a unified whole, better overcoming the bending deformation of individual battery cells. The reinforcing members and the flexible layer form a dual expansion force management system of rigid structural constraint + elastic material buffer, enabling the expansion force to be absorbed through the synergistic cooperation of the reinforcing members and the flexible layer, thereby optimizing the expansion force transmission path and achieving reliable control of the expansion force of the individual battery cells throughout their entire lifespan. Thus, the housing meets the core requirements of lightweight design, reliable full-life-cycle expansion force control, and efficient thermal management.

[0043] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0046] Figure 1 This is a schematic diagram of the structure of the battery pack provided in an exemplary embodiment of this disclosure; Figure 2 This is an exploded view of the battery pack provided in an exemplary embodiment of this disclosure; Figure 3 This is a top view of the battery pack provided in an exemplary embodiment of this disclosure; Figure 4 This is a schematic diagram of the structure of the first end plate provided in an exemplary embodiment of this disclosure; Figure 5 This is an exploded view of the connection between the housing and the tooling provided in the exemplary embodiments of this disclosure; Figure 6 This is a flowchart of an assembly method provided in an exemplary embodiment of this disclosure.

[0047] Explanation of reference numerals in the attached figures: 1. Housing; 11. Mounting cavity; 12. First end plate; 13. Second end plate; 14. First side plate; 15. Second side plate; 16. Lifting hole; 17. Flanged edge; 18. Mounting platform; 19. Connector; 191. Connecting hole; 2. Reinforcing component; 21. First reinforcing component; 22. Second reinforcing component; 3. Welding section; 4. Axis; 5. Flexible layer; 6. Membrane material; 61. Adhesive backing layer; 62. Release film layer; 63. Second positioning hole; 64. Third positioning hole; 7. Tooling; 71. First positioning hole; 72. Locking hole; 73. Positioning plug; 74. Positioning pin; 8. CCS assembly; 81. Bracket; 82. Aluminum busbar; 83. FPC acquisition board; 9. Insulating film; 100. Battery pack; 200. Individual battery cell. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0049] Among related technologies, the integration solutions for energy storage battery packs mainly include module integration solutions and cell-to-pack (CTP) solutions.

[0050] For module integration solutions, the core logic is "first assemble into clusters, then install in the battery box." Specifically, multiple individual battery cells are first stacked into battery clusters, with metal end plates at both ends. Steel strips are then wrapped around the metal end plates and the battery clusters to apply pre-tension, forming standardized battery modules. Multiple battery modules are then assembled into the battery box using fasteners, and finally, thermal management, high-voltage, and data acquisition structures are added to complete the integration of the energy storage battery pack.

[0051] However, the above module integration solution has the following drawbacks.

[0052] 1. Weak expansion force control and poor reliability throughout the entire life cycle. Because the battery module relies solely on the pre-tension force provided by the steel strip to constrain the expansion of individual cells, and the steel strip has a small cross-sectional area and limited tensile stiffness, when the expansion force surges at the end of the cell's lifespan, the steel strip is prone to plastic stretching and breakage, and the end plates are prone to warping and deformation. This can easily lead to uneven pressure distribution at the cell interface, accelerating cell capacity decay, and even triggering safety risks such as internal short circuits and thermal runaway within the cell. Furthermore, the steel strip pre-tension force cannot adapt to the dynamic changes in expansion and contraction throughout the cell's entire life cycle, resulting in extremely poor buffering capacity.

[0053] 2. Low assembly efficiency and poor weight reduction. Because battery modules require a large number of auxiliary structural components such as end plates, steel strips, and module fixing brackets, the proportion of ineffective structures is high, resulting in low volume assembly efficiency and significant loss of weight energy density at the battery pack level, which cannot meet the development trend of high integration and lightweighting of energy storage systems.

[0054] 3. Low thermal management efficiency. The end plates, steel strips, and other structures of the battery module itself isolate the individual cells from direct contact with the liquid cooling plate. Additional insulating pads, thermally conductive pads, and thermally conductive adhesives are required at the bottom of each individual cell, increasing the number of heat transfer interfaces and contact thermal resistance. This makes temperature difference control of individual cells difficult, severely impacting the temperature consistency and cycle life of the entire battery pack.

[0055] 4. Complex assembly process and high mass production cost. The battery pack requires multiple processes such as module prefabrication, module testing, and whole-pack assembly. It involves many types of materials, many production turnover links, and long production cycle, resulting in high manufacturing costs, material management costs, and production line investment costs.

[0056] For the CTP (Cell-to-Pack) solution, the core logic is "eliminating battery modules and directly inserting individual cells into the battery box." Specifically, it abandons the prefabricated battery module structure and directly stacks and assembles individual cells into the battery box. To control the expansion force of individual cells, expansion beams are typically installed inside the battery box, parallel to the stacking direction of the individual cells. These expansion beams are rigidly connected to the liquid cooling plate or the battery box wall through welding, relying on the structural rigidity of the expansion beams to constrain the expansion deformation of the individual cells.

[0057] However, the above-mentioned CTP (Cell-to-Pack) solution has the following drawbacks.

[0058] 1. An unreasonable expansion force transmission path leads to the easy failure of core components and high safety risks. The expansion force generated throughout the entire life cycle of a single battery cell acts directly on the expansion beam. Since the expansion beam is welded to the liquid cooling plate, the expansion stress will be directly transmitted to the liquid cooling plate without buffering. This can easily cause cracking, displacement, and structural failure at the weld between the expansion beam and the liquid cooling plate, as well as plastic deformation and weld tearing in the liquid cooling plate. Consequently, the airtightness of the liquid cooling circuit inside the liquid cooling plate may fail, leading to safety accidents such as cooling medium leakage and insulation breakdown.

[0059] 2. Lightweight design and structural strength cannot be balanced, resulting in high design redundancy. To ensure the stress requirements of the expansion beam, the liquid cooling plate and battery box need to be thickened and reinforced, which significantly increases the weight of the battery box. This completely negates the lightweight advantage of the CTP solution, resulting in high design redundancy and violating the original design intent of CTP technology.

[0060] 3. Assembly and maintenance are extremely difficult, resulting in high life-cycle costs and poor maintainability. The expansion beam and liquid cooling plate are connected using a welding process, forming a non-removable connection structure. This severely restricts the operational space for assembling individual cells and subsequent maintenance. When a single cell fails, it cannot be disassembled and replaced individually; the entire cell must be scrapped, leading to extremely high maintenance costs, poor economic efficiency, and an inability to meet the long-term service requirements of energy storage systems.

[0061] 4. Low integration and poor compatibility with high-voltage structures. The expansion beam is built into the battery box, occupying a large amount of internal space. This makes it impossible to achieve integrated design of the acquisition components and high-voltage connection structure, requiring additional brackets and fasteners, further reducing space utilization. Furthermore, the acquisition harness is easily damaged by expansion and compression, resulting in poor signal acquisition reliability.

[0062] Based on this, and in accordance with the first aspect of this application, referring to Figures 1 to 4This disclosure provides a battery pack 100. The battery pack 100 includes a housing 1, individual battery cells 200, and a flexible layer 5. An installation cavity 11 is formed inside the housing 1, and the installation cavity 11 extends through the housing 1 along a first direction. Reinforcing members 2 are provided on the end faces of opposite ends of the housing 1 in a second direction. The reinforcing members 2 extend along a third direction. The individual battery cells 200 are disposed in the installation cavity 11, and at least two individual battery cells 200 are provided. The at least two individual battery cells 200 are stacked in the installation cavity 11 along the second direction. The flexible layer 5 is disposed in the installation cavity 11 and is located between the individual battery cells 200 and the housing wall of the housing 1. The first direction, the second direction, and the third direction are all angularly positioned between each other.

[0063] Through the above technical solution, by setting a mounting cavity 11 that runs through the housing 1 along the first direction, the bottom of the individual battery cell 200 is exposed after being placed in the mounting cavity 11, without structural obstruction. This provides a basis for direct heat transfer between the individual battery cell 200 and the liquid cooling plate, shortening the heat transfer path and reducing contact thermal resistance. Reinforcing members 2 are set at the end faces of opposite ends of the housing 1 in the second direction. These reinforcing members 2 bear the full-cycle expansion force constraint of the individual battery cell 200 from its initial stage to the end of its lifespan, eliminating the need for additional expansion beams. The flexible layer 5 allows all the battery cells to form a unified whole, better overcoming the bending deformation of the individual battery cell 200. The reinforcing members 2 and the flexible layer 5 form a dual expansion force management system of rigid structural constraint + elastic material buffer, allowing the expansion force to be absorbed through the synergistic cooperation of the reinforcing members 2 and the flexible layer 5, thereby optimizing the expansion force transmission path and achieving reliable control of the expansion force of the individual battery cell 200 throughout its entire life cycle. Thus, the housing 1 meets the core requirements of lightweight design, reliable full-life-cycle expansion force control, and efficient thermal management.

[0064] In some embodiments, the flexible layer 5 is a foamed adhesive layer.

[0065] like Figure 1 As shown, after at least two individual battery cells 200 are stacked along the second direction within the mounting cavity 11, expanding foam is injected into the housing 1. The expanding foam fills the gaps between the sides of the individual battery cells 200 and the walls of the housing 1, as well as the gaps between the end faces of the individual battery cells 200 and the walls of the housing 1. After the expanding foam cures, it forms a flexible layer 5, which is a continuous elastic filling layer that can wrap all the individual battery cells 200, thereby forming an integral rigid structure with the housing 1.

[0066] Because the cured flexible layer 5 has excellent elastic strain capacity, it can absorb the expansion stress generated by the individual battery cell 200 during cycling through its own compression deformation. Therefore, the flexible layer 5 can significantly reduce the impact of the expansion force of the individual battery cell 200 on the side wall of the housing 1, preventing excessive deformation of the housing 1 structure; on the other hand, it can ensure a uniform distribution of interfacial pressure on the individual battery cell 200, preventing localized stress concentration that could lead to performance degradation of the individual battery cell 200, thus delaying the lifespan degradation of the individual battery cell 200 and improving its cycle life.

[0067] The flexible layer 5 also possesses excellent insulation and structural fixation properties, enabling the insulation isolation and positional fixation of individual battery cells 200, preventing displacement, vibration, and movement of the individual battery cells 200 during transportation and service. The expanding foam connects all the individual battery cells 200 into a single unit, improving the bending deformation of the individual battery cells 200 and confining their expansion within the area enclosed by the flexible layer 5. Furthermore, the flexible layer 5 itself absorbs the expansion deformation, ensuring that the expansion deformation of the individual battery cells 200 does not interfere with other structural components.

[0068] In other embodiments of this application, the flexible layer 5 may also be formed by a structure such as foam, or by a composite structure layer of foam and aerogel felt sandwiched together to form the flexible layer 5, as long as the flexible layer 5 can absorb the amount of expansion deformation through its own deformation. The specific material of the flexible layer 5 is not limited in the embodiments of this application.

[0069] In some embodiments, a reinforcing member 2 located at one end of the housing 1 is disposed on the outer end face of the housing 1, and a reinforcing member 2 located at the other end of the housing 1 is disposed on the inner end face of the housing 1.

[0070] In some embodiments, the reinforcing members 2 located at both ends of the housing 1 are located on the outer end face of the housing 1.

[0071] like Figure 1 As shown, by setting reinforcement 2 on the outside of the housing 1, so that there are no redundant structures such as built-in expansion beams and reinforcing ribs inside the housing 1, the internal installation space of the housing 1 can be maximized, and the individual battery cells 200 can be directly stacked and assembled in the mounting cavity 11 along the second direction. Since the mounting cavity 11 penetrates the housing 1 along the first direction, the bottom of the housing 1 forms a completely open bottomless structure, and the bottom of the individual battery cells 200 is exposed after stacking. At this time, only the entire surface of PET blue film can be attached to the bottom of the individual battery cells 200 for insulation protection, without any other structural obstruction, providing an unobstructed path for direct bonding and heat transfer between the individual battery cells 200 and the liquid cooling plate.

[0072] like Figure 2 and Figure 4As shown, in some embodiments, the reinforcing member 2 is welded to the outer surface of the housing 1. The weld between the reinforcing member 2 and the housing 1 forms a welded portion 3, and the outer surface of the welded portion 3 is configured as an arc surface or a bevel.

[0073] It is understandable that the casing 1 is an integral structural component formed by sheet metal stamping and bending process, and the reinforcing component 2 is fixed to the casing 1 by welding process, so as to realize the forming of battery box without complicated machining process, which has the advantages of simple process and strong mass production capability.

[0074] Grinding the outer surface of weld 3 into an arc surface can eliminate stress concentration, significantly improve fatigue life, reduce the risk of gravitational corrosion cracking, and also reduce the probability of crack initiation. At the same time, it can improve the appearance regularity and facilitate non-destructive testing.

[0075] Grinding the outer surface of weld 3 into a bevel can reduce the stiffness difference caused by abrupt interface changes, improve stress distribution, and extend fatigue life. It also improves appearance regularity and facilitates non-destructive testing.

[0076] In some embodiments, the reinforcing member 2 is fixed to the housing 1 by a fillet weld full welding process.

[0077] In some embodiments, at least two individual battery cells 200 are stacked along a second direction to form a battery cluster. At least two battery clusters may be disposed within the mounting cavity 11 of the housing 1, and the at least two battery clusters are spaced apart along a third direction.

[0078] In some embodiments, each pair of the first direction, the second direction, and the third direction is set at an acute angle; or, each pair of the first direction, the second direction, and the third direction is set at a right angle; or, each pair of the first direction, the second direction, and the third direction is set at an obtuse angle.

[0079] For example, the first direction is the height direction of the box 1, the second direction is the length direction of the box 1, and the third direction is the width direction of the box 1.

[0080] like Figure 3 As shown, in some embodiments, along a third direction, there is a first gap between the individual cell 200 and the wall surface of the housing 1. The first gap is configured to accommodate at least a portion of the flexible layer 5, wherein the width of the first gap is D1, which satisfies: 4 mm ≤ D1 ≤ 10 mm.

[0081] Understandably, the first gap serves two purposes: firstly, it acts as a channel for the expansion foam to solidify and form a flexible layer 5; secondly, it serves as a buffer space for the lateral expansion of the individual battery cell 200. Setting the width of the first gap to between 4 mm and 10 mm ensures that the expansion foam, after being injected into the first gap, can evenly fill the space between the individual battery cell 200 and the wall of the housing 1, forming a continuous buffer layer. This layer can accommodate the thickness expansion of the individual battery cell 200 throughout its entire lifecycle, preventing the expanded individual battery cell 200 from directly compressing the side wall of the housing 1. Simultaneously, it provides a process tolerance gap for the stacking and assembly of the individual battery cells 200, reducing the assembly difficulty of placing the individual battery cells 200 into the housing.

[0082] In some embodiments, the width of the first gap is set to 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, or any value between any two.

[0083] Please continue reading. Figure 3 In some embodiments, along the second direction, there is a second gap between the individual cell 200 and the wall surface of the housing 1. The second gap is configured to accommodate at least a portion of the flexible layer 5, wherein the width of the second gap is D2, which satisfies: 5 mm ≤ D2 ≤ 25 mm.

[0084] Understandably, the second gap can serve as a channel for the expansion foam, allowing it to cure and form a flexible layer 5. The width of the second gap is set to a range of 5 mm to 25 mm to accommodate the dimensional tolerances of the stacked individual battery cells 200, reducing the assembly difficulty of placing the individual battery cells 200 into the casing. Simultaneously, it serves as a space for the expansion foam, providing insulation protection and buffering for the individual battery cells 200, and providing installation space for the high-voltage connection structure at the ends.

[0085] In some embodiments, the width of the second gap is set to 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, or any value between the two.

[0086] Please continue reading. Figure 3 In some embodiments, along the second direction, there is a third gap between every two adjacent individual cells 200, the third gap being configured to accommodate a buffer pad, wherein the width of the third gap is D3, satisfying: 1 mm ≤ D3 ≤ 6 mm.

[0087] Understandably, the third gap serves two purposes: firstly, as a gap between each pair of adjacent individual cells 200, it provides thermal barrier between the two adjacent individual cells 200, preventing the thermal spread of the individual cell 200 after thermal runaway; secondly, it accommodates a buffer pad to further absorb the expansion force of the individual cell 200 during charge and discharge cycles.

[0088] In some embodiments, the width of the third gap is set to 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, or any value between any two.

[0089] In some embodiments, the battery pack 100 further includes a liquid cooling plate, which is detachably connected to the bottom of the housing 1 and closes one side of the mounting cavity 11.

[0090] Understandably, the liquid cooling plate is connected to the bottom of the housing 1 and seals one side of the mounting cavity 11. Since the mounting cavity 11 extends through the height of the housing 1, the individual battery cell 200, after being placed in the housing 1, can directly contact the liquid cooling plate, or contact the liquid cooling plate through the thermally conductive adhesive layer and the insulating film 9. This results in a shorter heat transfer path and lower contact thermal resistance between the individual battery cell 200 and the liquid cooling plate.

[0091] In some embodiments, the liquid cooling plate is provided with a medium flow channel for the flow of a heat-conducting medium. When the heat-conducting medium is at a low temperature, the liquid cooling plate can cool the individual battery cell 200; when the heat-conducting medium is at a high temperature, the liquid cooling plate can heat the individual battery cell 200.

[0092] In some embodiments, the medium flow channel is configured in a serpentine shape to facilitate the circulation and heat exchange of the heat-conducting medium for the individual battery cell 200.

[0093] In some embodiments, insulating powder is also sprayed onto the liquid cooling plate to form a surface insulating layer. The thickness of the surface insulating layer can be set to micrometers.

[0094] In some embodiments, the battery pack 100 further includes an insulating film 9 disposed between the liquid cooling plate and the individual battery cell 200.

[0095] Understandably, since the mounting cavity 11 extends through the housing 1 along the first direction, the bottom of the housing 1 forms a completely open, bottomless structure, exposing the bottom of the stacked individual battery cells 200. At this time, only the entire surface of the insulating film 9 can be attached to the bottom of the individual battery cell 200 for insulation protection, without any other structural obstruction, providing an unobstructed path for direct bonding and heat transfer between the individual battery cell 200 and the liquid cooling plate.

[0096] In some embodiments, the insulating film 9 is a PET blue film.

[0097] Please continue reading. Figure 3In some embodiments, along the second direction, the insulating film 9 includes a first fold portion protruding from the housing 1, the first fold portion being configured to adhere to the outer surface of the housing 1 after folding, the width of the first fold portion being D4, satisfying: 5 mm ≤ D4 ≤ 10 mm; and / or, along the third direction, the insulating film 9 includes a second fold portion protruding from the housing 1, the second fold portion being configured to adhere to the outer surface of the housing 1 after folding, the width of the second fold portion being D5, satisfying: 5 mm ≤ D5 ≤ 10 mm.

[0098] In the second direction, the insulating film 9 protrudes from the housing 1 to form a first fold. The width of the first fold is set to 5 mm to 10 mm. On the one hand, this ensures that after the bottom surface of the individual battery cell 200 is attached to the insulating film 9, it can achieve unobstructed and complete bonding with the liquid cooling plate, avoiding interference with the structure of the housing 1. On the other hand, it provides operating space for the installation of the insulating film 9, ensuring that the insulating film 9 is installed flat and without wrinkles, while avoiding damage to the housing of the individual battery cell 200 caused by the bottom of the individual battery cell 200 rubbing against the housing 1 during hoisting and assembly.

[0099] In some embodiments, the width of the first fold is set to 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, or any value between the two.

[0100] On the third side, the insulating film 9 protrudes from the housing 1 to form a second fold. The width of the second fold is set to 5 mm to 10 mm. On the one hand, this ensures that after the bottom surface of the individual battery cell 200 is attached to the insulating film 9, it can achieve unobstructed and complete bonding with the liquid cooling plate, avoiding interference with the structure of the housing 1. On the other hand, it provides operating space for the installation of the insulating film 9, ensuring that the insulating film 9 is installed flat and without wrinkles, while avoiding damage to the housing of the individual battery cell 200 by scraping against the housing 1 during hoisting and assembly.

[0101] In some embodiments, the width of the second fold is set to 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, or any value between the two.

[0102] It should be noted that the liquid cooling plate is installed after the insulating film 9 is attached to the bottom of the housing 1 and both the first and second folded portions are folded and stacked on the outer surface of the housing 1. The battery pack 100 may also include a shell; after the housing 1 and the liquid cooling plate are assembled, the entire assembly is placed inside the shell. Thus, the battery pack 100 is sealed through this shell, and the connection interface between the housing 1 and the liquid cooling plate does not require sealing. Therefore, the insulating film 9 between the housing 1 and the liquid cooling plate will not affect the sealing performance of the battery pack 100.

[0103] like Figure 1 and Figure 3As shown, in some embodiments, the battery pack 100 further includes a CCS assembly 8 (Cells Contact System), which is disposed inside the housing 1 and connected to the individual cell 200. Along a third direction, the distance between the side of the individual cell 200 and the side of the CCS assembly 8 is D6, satisfying: 30 mm ≤ D6 ≤ 80 mm.

[0104] Understandably, in the third direction, the CCS module 8 does not completely cover the individual cell 200, so that the CCS module 8 has a gap of 30 mm to 80 mm between the two ends of the individual cell 200. This reduces the material consumption of the CCS module 8 and achieves cost reduction.

[0105] In some embodiments, the distance between the side of the individual cell 200 and the side of the CCS assembly 8 is set to 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, or any value between the two.

[0106] In some embodiments, along the first direction, the distance between the top surface of the CCS component 8 and the top surface of the housing 1 is D7, satisfying: 5 mm ≤ D7 ≤ 30 mm.

[0107] Understandably, in the first direction, the distance between the top surface of the CCS component 8 and the top surface of the housing 1 is set in the range of 5 mm to 30 mm, thereby ensuring sufficient electrical clearance and creepage distance between the CCS component 8 and the housing cover, and ensuring absolute thermal safety.

[0108] In some embodiments, the distance between the top surface of the CCS component 8 and the top surface of the housing 1 is set to 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, or any value between the two.

[0109] The battery pack 100 in this embodiment of the application, based on the settings of the above parameters, forms a multi-dimensional fitting gap between the individual battery cell 200 and the housing 1, so as to take into account the assembly process, potting filling performance and expansion and impact requirements.

[0110] like Figure 2 As shown, in some embodiments, the CCS assembly 8 includes a bracket 81, an aluminum busbar 82, and an FPC acquisition board 83. The aluminum busbar 82 and the FPC acquisition board 83 are both connected to the bracket 81. The aluminum busbar 82 is electrically connected to the FPC acquisition board 83. The aluminum busbar 82 is configured to be welded to the pole of the individual battery cell 200.

[0111] Understandably, the CCS component 8 is composed of a bracket 81, an aluminum busbar 82, and an FPC acquisition board 83, forming a fully integrated FPC acquisition solution. The bracket 81 is a vacuum-formed bracket, an integrated insulating structure used to fix the aluminum busbar 82 and the PFC acquisition board, enabling precise positioning and insulation isolation of the aluminum busbar 82. The FPC acquisition board 83 integrates voltage and temperature acquisition circuits, thereby acquiring the voltage and temperature parameters of the individual battery cell 200, achieving real-time acquisition of all parameters of the individual battery cell 200, eliminating the problem of messy wiring.

[0112] During the assembly of the battery pack 100, the CCS module 8 is installed after the foam adhesive has cured inside the housing 1. Specifically, the CCS module 8 is hoisted and placed over the top of all individual battery cells 200. Precise alignment of the CCS module 8 is achieved through the positioning structure of the bracket 81 and the housing 1, ensuring that the aluminum busbar 82 is fully attached to the terminal post of the individual battery cell 200. Then, the aluminum busbar 82 is welded to the terminal post using laser welding, enabling series, parallel, or mixed connection (mixed connection refers to a group of individual battery cells 200 connected in series and then in parallel with another group of individual battery cells 200) of the individual battery cells 200. Simultaneously, the acquisition terminals of the FPC acquisition board 83 are reliably connected to the aluminum busbar 82 and the temperature measurement points of the individual battery cells 200, achieving stable acquisition of cell voltage and temperature signals.

[0113] An FPC-type CCS assembly 8 is applied within the enclosure 1, allowing it to be fully compatible with the enclosure 1, which lacks expansion beams. The absence of expansion beams within the enclosure 1 enables the integral installation of the CCS assembly 8, eliminating the need for segmented splicing and significantly improving assembly efficiency. Furthermore, the bracket 81 provides full-range insulation protection, preventing the risk of insulation breakdown between high-voltage components and the enclosure 1. The FPC acquisition solution can accommodate slight expansion and displacement of individual battery cells 200, avoiding the tearing problem caused by compression in wire harness solutions, thus greatly improving the reliability of signal acquisition.

[0114] In some embodiments, the reinforcing member 2 is hollow inside, and its longitudinal section is set to one of polygonal, circular, or elliptical shapes.

[0115] It is understandable that the stiffener 2 is designed to be hollow inside, so that it forms a closed cross section. The longitudinal section of the stiffener 2 is designed to be one of polygonal, circular, or elliptical shapes, so that the stiffener 2 has a large moment of inertia.

[0116] For example, the longitudinal section of the reinforcing member 2 is set to be rectangular, trapezoidal, circular or elliptical.

[0117] like Figure 4 As shown, in some embodiments, the longitudinal section of the reinforcing member 2 is set as rectangular.

[0118] Understandably, the reinforcing member 2 is an internally hollow rectangular structure, a one-piece rectangular reinforcing square tube. This rectangular reinforcing square tube can be integrally formed by bending sheet metal. The reinforcing member 2 extends along a third direction and has a closed rectangular cross-section, giving it a very large moment of inertia. Compared to traditional steel strip solutions, the rectangular reinforcing square tube can provide a much larger tensile cross-sectional area and bending stiffness in the expansion direction of the individual battery cell 200, independently bearing the full-cycle expansion force constraint of the individual battery cell 200 from its initial stage to the end of its lifespan, without the need for additional expansion beams.

[0119] Compared to circular or elliptical longitudinal sections, the longitudinal section of the reinforcing member 2 in this embodiment is set to a rectangle, which facilitates the fixing and welding of the reinforcing member 2 on the outer surface of the first end plate 12 or the second end plate 13, so that the reinforcing member 2 can be accurately set in a preset position.

[0120] Compared to trapezoidal or other polygonal longitudinal sections, the longitudinal section of the reinforcing member 2 in this embodiment is set to a rectangle, which can achieve the best strength, stiffness and bending performance with minimal material consumption, and is easy to manufacture.

[0121] It should be noted that, for the reinforcing member 2 with a rectangular cross-section, in order to meet the expansion force requirements of different individual battery cells 200, the dimensions of the reinforcing member 2 in the first and second directions can be reasonably set. Specifically, the dimension of the reinforcing member 2 in the first direction should not be too large to avoid reducing its bending resistance.

[0122] like Figure 4 As shown, in some embodiments, the reinforcing member 2 is provided as at least two, and the at least two reinforcing members 2 are spaced apart along the first direction.

[0123] It is understandable that by setting at least two reinforcing members 2, the expansion force of the individual battery cell 200 can be resisted by the joint efforts of the two reinforcing members 2, so as to ensure that the housing 1 can reliably control the expansion force of the individual battery cell 200 throughout its entire life cycle.

[0124] For example, two reinforcing members 2 are provided. Alternatively, three, four or more reinforcing members 2 can be provided. The number of reinforcing members 2 can be reasonably selected based on the expansion force requirements of the individual battery cell 200, the size of the reinforcing member 2, and the overall bending resistance requirements of the housing 1.

[0125] Please continue reading. Figure 4 In some embodiments, the single cell 200 has an axis 4 parallel to a third direction, and two reinforcing members 2 are provided, namely a first reinforcing member 21 and a second reinforcing member 22, wherein the first reinforcing member 21 and the second reinforcing member 22 are located on opposite sides of the axis 4.

[0126] It is understandable that the reinforcing member 2 is set as the first reinforcing member 21 and the second reinforcing member 22, and the first reinforcing member 21 and the second reinforcing member 22 are located on opposite sides of the axis 4, so that the first reinforcing member 21 and the second reinforcing member 22 can respectively bear the expansion force of the single cell 200 near the upper part and the expansion force near the lower part.

[0127] It should be noted that although neither the first reinforcing member 21 nor the second reinforcing member 22 is located on the axis 4 of the single cell 200, neither of them is too far from the axis 4, so as to ensure that both the first reinforcing member 21 and the second reinforcing member 22 can resist the expansion and deformation of the single cell 200 in a suitable position.

[0128] Please continue reading. Figure 4 In some embodiments, the first reinforcing member 21 is located above the second reinforcing member 22. Along the first direction, the distance between the first reinforcing member 21 and the axis 4 is D8, and the distance between the second reinforcing member 22 and the axis 4 is D9, satisfying: D8 > D9.

[0129] Understandably, after all the individual battery cells 200 are stacked inside the housing 1, foam is also placed between the individual battery cells 200 and the first end plate 12 or the second end plate 13. When the individual battery cell 200 expands, its deformation is mainly concentrated in the area along axis 4. The area along axis 4 and the upper part of axis 4 can jointly resist the expansion force under the action of the first reinforcing member 21 and the upper foam. The area along axis 4 and the lower part of axis 4 can jointly resist the expansion force under the action of the second reinforcing member 22 and the lower foam. Along the height direction of housing 1, the foam has the characteristic of being tighter at the top and looser at the bottom. Therefore, by making the first reinforcing member 21 at the top further away from axis 4 and the second reinforcing member 22 at the bottom closer to axis 4, the second reinforcing member 22 is closer to the area where the expansion is concentrated, which can better resist the expansion deformation of the individual battery cell 200.

[0130] For example, the distance between the first reinforcing member 21 and the axis 4 is 5 mm, and the distance between the second reinforcing member 22 and the axis 4 is 3 mm. It is sufficient to ensure that the second reinforcing member 22 is closer to the axis 4 than the first reinforcing member 21. This embodiment of the application does not limit the distance between the first reinforcing member 21 and the axis 4, nor the distance between the second reinforcing member 22 and the axis 4.

[0131] It should be noted that the distance between the first reinforcing member 21 and the axis 4 is the distance between the side of the first reinforcing member 21 closest to the axis 4 and the axis 4. The distance between the second reinforcing member 22 and the axis 4 is the distance between the side of the second reinforcing member 22 closest to the axis 4 and the axis 4.

[0132] Please continue reading. Figure 4In some embodiments, the thickness of the reinforcing member 2 is D10, satisfying: 1 mm ≤ D10 ≤ 2 mm.

[0133] Understandably, the thickness of the reinforcing member 2 is set in the range of 1 mm to 2 mm to ensure that the reinforcing member 2 has good strength to resist the expansion force of the single cell 200, while also ensuring that the overall weight is light.

[0134] When the thickness of the reinforcing member 2 is less than 1 mm, its own strength is insufficient, which may cause the reinforcing member 2 to be unable to resist the expansion force of the single cell 200, or the reinforcing member 2 to deform too much when resisting the expansion force, thus failing to meet the usage requirements. When the thickness of the reinforcing member 2 exceeds 2 mm, it will cause the weight of the reinforcing member 2 to increase too much, and the cost will increase excessively, while the difficulty of processing and forming will increase dramatically.

[0135] In some embodiments, the thickness of the reinforcing member 2 is set to 1 mm, 1.5 mm, 2 mm, or any value between the two.

[0136] In some embodiments, the housing 1 is an integral structural component.

[0137] Since the housing 1 is an integral structural component, the complex machining process required for housing 1 is greatly simplified, the mold investment cost is low, and the mass production adaptability is strong.

[0138] For example, such as Figure 2 As shown, the housing 1 includes a first end plate 12, a second end plate 13, a first side plate 14, and a second side plate 15. The first end plate 12 and the second end plate 13 are spaced apart along a second direction, and the first side plate 14 and the second side plate 15 are spaced apart along a third direction. The first end plate 12, the second end plate 13, the first side plate 14, and the second side plate 15 together form a rectangular housing 1.

[0139] The first side plate 14, the second side plate 15, the first end plate 12, and the second end plate 13 are integrally formed without any built-in expansion beams. Specifically, the housing 1 is integrally formed by sheet metal stamping and bending to form a channel-shaped structure, which serves as the mounting cavity 11. There are no redundant structures such as built-in expansion beams or reinforcing ribs in the mounting cavity 11, and the individual battery cells 200 can be directly stacked and assembled in the mounting cavity 11 along the length of the housing 1. The bottom of the formed mounting cavity 11 is open, so that the bottom of the housing 1 is a completely open bottomless structure, and the bottom of the individual battery cells 200 is exposed without structural obstruction, providing a basis for direct heat conduction between the individual battery cells 200 and the liquid cooling plate.

[0140] In some embodiments, the housing 1 is made of 6061-T6 high-strength aluminum alloy sheet. Therefore, the first side plate 14, the second side plate 15, the first end plate 12, and the second end plate 13 are all made of 6061-T6 high-strength aluminum alloy sheet. This gives the housing 1 excellent mechanical properties and corrosion resistance, while also providing low density and good bending and welding processability. It achieves extreme lightweighting while meeting the expansion force bearing strength requirements, thus balancing high strength, lightweighting, and excellent bending and welding performance, making it suitable for the service environment of energy storage systems.

[0141] Please continue reading. Figure 4 In some embodiments, the first end plate 12 and / or the second end plate 13 are provided with a connector 19, which is spaced apart from the reinforcing member 2 along a first direction, wherein the connector 19 is configured to be connected to the liquid cooling plate by fasteners.

[0142] It is understandable that fasteners are used to achieve a detachable rigid connection between the connector 19 and the liquid cooling plate. By replacing welding with a detachable fastener connection, when the expansion force is transmitted to the housing 1 or the reinforcing member 2, the expansion force of the individual cell 200 is almost entirely borne by the housing 1, and is largely not transmitted to the liquid cooling plate. This prevents the liquid cooling plate from undergoing plastic deformation due to the expansion force, avoiding safety accidents such as liquid cooling circuit airtightness failure, heat transfer medium leakage, and insulation breakdown. This essentially solves the core safety hazard of expansion force causing liquid cooling plate failure, achieving reliable control of the expansion force of the individual cell 200 throughout its entire life cycle, and improving the safety of the energy storage system during long-term service.

[0143] The detachable connection between the housing 1 and the liquid cooling plate via fasteners reduces the difficulty and cost of later maintenance. During later maintenance, the housing 1 can be disassembled as a whole to facilitate the replacement of faulty individual cells 200. Compared to the welded connection between the housing 1 and the liquid cooling plate, the detachable connection structure can reduce maintenance costs by more than 85%, significantly reducing the total lifecycle operating cost of the energy storage system.

[0144] In some embodiments, the fastener is a bolt. The bolt length is set to 3 mm to 5 mm so that the bolt does not substantially transmit expansion forces to the liquid cooling plate.

[0145] It should be noted that the connector 19 not only enables a detachable rigid connection between the housing 1 and the liquid cooling plate, but also strengthens the structure, further enhancing the overall structural rigidity and deformation resistance of the housing 1.

[0146] In some embodiments, the connector 19 is disposed near the bottom of the first end plate 12 and / or the second end plate 13, and is located on the outer surface of the first end plate 12 and / or the second end plate 13. The connector 19 extends in a third direction.

[0147] In some embodiments, a connector 19 is provided on both the first end plate 12 and the second end plate 13.

[0148] Please continue reading. Figure 4 In some embodiments, the connector 19 is provided with a connection hole 191, which is configured to be connected to the liquid cooling plate by a fastener and to pass through a positioning pin 74 to position and connect the membrane material 6 to the housing 1.

[0149] Understandably, the connector 19 can not only achieve a detachable rigid connection between the housing 1 and the liquid cooling plate in the final molding stage, but also pass through the positioning pin 74 during the molding process to achieve a positioning connection between the membrane material 6 and the housing 1, thereby ensuring that the membrane material 6 is flat, wrinkle-free and accurately connected to the housing 1.

[0150] In some embodiments, the connector 19 is provided with at least two connection holes 191, which are spaced apart along a third direction.

[0151] Please continue reading. Figure 4 In some embodiments, the connector 19 is a hollow structure integrally bent, one end of the connector 19 is integrally formed with the first end plate 12 or the second end plate 13, and the other end of the connector 19 is welded to the corresponding first end plate 12 or the second end plate 13.

[0152] It is understandable that the connector 19 is integrally formed on the first end plate 12 or the second end plate 13, and is welded to form a rectangular closed structure, so that the box body 1 is basically formed by sheet metal stamping and bending, and combined with full welding of fillet welds, to achieve forming without complex machining. As a result, the mold investment of the box body 1 is low, the production efficiency is high, and it is suitable for large-scale mass production.

[0153] like Figure 1 and Figure 2 As shown, in some embodiments, the housing 1 is also connected to mounting platforms 18 at opposite ends in the second direction, and the mounting platforms 18 are configured to connect to the output aluminum busbars of the individual battery cells 200.

[0154] It is understandable that the housing 1 is also connected to the mounting platform 18 at both ends in the second direction, which can be used to integrate the fixed mounting base of the output aluminum busbar of the single cell 200, realize the integrated design of the high voltage output structure, so that there is no need to set up an additional aluminum busbar fixing bracket, which can reduce the number of parts.

[0155] In some embodiments, the mounting platform 18 is provided with mounting holes for use with bolts and nuts to lock the aluminum busbar 82. The size of the mounting platform 18 can be reasonably selected based on the size of the individual battery cell 200.

[0156] In some embodiments, the mounting platform 18 is a hollow structure integrally bent, with one end of the mounting platform 18 integrally formed with the first end plate 12 or the second end plate 13, and the other end of the mounting platform 18 welded to the corresponding first end plate 12 or the second end plate 13.

[0157] Understandably, the mounting platform 18 is integrally formed on the first end plate 12 or the second end plate 13, and is welded to form a rectangular closed structure, so that the housing 1 is basically formed by sheet metal stamping and bending, combined with full welding of fillet welds, to achieve forming without complex machining. As a result, the mold investment for the housing 1 is low, the production efficiency is high, and it is suitable for large-scale mass production.

[0158] Based on the fact that mounting platforms 18 are integrally formed at both ends of the housing 1 to connect the output aluminum busbars 82 of the individual battery cells 200, there is no need to set up additional mounting brackets 81 for the aluminum busbars 82, which reduces the number of parts and realizes the integrated design of the high voltage structure.

[0159] Please continue reading. Figure 1 and Figure 2 In some embodiments, a lifting hole 16 is formed on the housing 1, and a flange 17 is formed on the outer surface of the housing 1 surrounding the lifting hole 16.

[0160] It is understandable that by providing lifting holes 16 on the housing 1, the housing 1 can be lifted, thus adapting to automated production line operations. The flanges 17 surrounding the lifting holes 16 can significantly improve the strength of the lifting structure and meet the stress requirements for the overall lifting of the housing 1 after the foam has cured.

[0161] The flange 17 is a structure that protrudes outward from the outer surface of the sheet metal. Compared to an inwardly protruding structure, the flange 17 can prevent the individual battery cells 200 from being bumped or scratched during stacking, and can also prevent the metal parts from affecting the insulation of the individual battery cells 200 after the inward protrusion. At the same time, since the lifting tools need to pass through the lifting hole 16 during the hoisting process, the outwardly protruding flange 17 structure can reduce the extent to which the lifting tools penetrate into the housing 1, thereby improving the safety of the hoisting process.

[0162] When at least one of the first side plate 14, the second side plate 15, the first end plate 12, and the second end plate 13 is provided with a lifting hole 16, an outwardly protruding flange 17 is formed at the position of each lifting hole 16. That is, one lifting hole 16 corresponds to one flange 17.

[0163] In some embodiments, at least two lifting holes 16 are provided on both the first side plate 14 and the second side plate 15, and the lifting holes 16 on the first side plate 14 and the lifting holes 16 on the second side plate 15 are symmetrically arranged.

[0164] In some embodiments, at least two lifting holes 16 are provided on both the first end plate 12 and the second end plate 13, and the lifting holes 16 on the first end plate 12 and the lifting holes 16 on the second end plate 13 are symmetrically arranged.

[0165] In some embodiments, the first side plate 14, the second side plate 15, the first end plate 12, and the second end plate 13 are all provided with lifting holes 16.

[0166] In some embodiments, the lifting hole 16 is a circular hole, and the flange 17 is set as an annular shape.

[0167] In the battery pack 100 of this application embodiment, the traditional module's end plate, steel strip, and other easily damaged structures, as well as the built-in expansion beam design of conventional CTP solutions, are completely eliminated. Instead, an integrated high-rigidity housing 1 independently bears the expansion force constraint function of a single cell 200 throughout its entire life cycle, and a flexible layer 5 filling system achieves expansion stress buffering. An open bottom structure optimizes the thermal management path, a multi-dimensional gap design balances assembly, potting, and expansion buffering requirements, and an FPC-type CCS component 8 achieves integrated design of the high-voltage and acquisition structures, ultimately forming a highly integrated, highly reliable, and minimally invasive energy storage module solution.

[0168] The battery pack 100 of this application utilizes a dual expansion force management system consisting of the reinforcing member 2 and the flexible layer 5, achieving a qualitative leap in the reliability of the individual battery cell 200 throughout its entire life cycle. The rectangular reinforcing square tube, with its continuous, integrated closed design, provides a tensile cross-sectional area and moment of inertia far exceeding traditional steel strip solutions, increasing bending stiffness by over 50%. This effectively constrains the expansion deformation of the individual battery cell 200 throughout its life cycle, preventing excessive deformation and failure of the housing 1. Combined with the elastic strain buffer of the flexible layer 5, a dual expansion force management system is formed, consisting of rigid housing 1 constraint and elastic colloidal buffer. Over 60% of the cell expansion stress is absorbed by the flexible layer 5, significantly reducing the stress load on the housing 1. Simultaneously, it ensures uniform pressure distribution at the interface of the individual battery cell 200, delaying capacity decay and increasing the cycle life of the individual battery cell 200 by over 25%.

[0169] The enclosure 1 and the liquid cooling plate are detachably connected. The expansion force of the individual battery cell 200 is almost entirely borne by the enclosure 1 independently, which avoids the transmission of expansion force to the liquid cooling plate and prevents safety hazards such as deformation of the liquid cooling plate, weld cracking, and airtight / liquid tightness failure caused by expansion force. This significantly improves the safety and stability of the energy storage system during long-term service. At the same time, the enclosure 1 and the liquid cooling plate are detachably locked, without welded fixing structure. The module can be disassembled as a whole for maintenance, and individual battery cells can be easily replaced in case of failure. Compared with the conventional welded CTP solution, maintenance costs are reduced by more than 85%, which greatly reduces the total life cycle operating cost of the energy storage system.

[0170] By eliminating the end plates, steel strips, and binding straps of traditional battery modules, as well as a large number of redundant auxiliary structural components such as the built-in expansion beams in conventional CTP solutions, the internal space utilization of the housing 1 is increased by more than 20%, and the overall weight is reduced by more than 15%. This significantly improves the volumetric assembly efficiency and gravimetric energy density, perfectly aligning with the development trend of high integration and lightweight energy storage systems. At the same time, the number of parts is reduced by more than 40%, significantly reducing material management costs and assembly complexity.

[0171] Thermal management efficiency is significantly improved, and cell consistency is significantly optimized. Based on the completely open structure of the bottom of the housing 1, the individual cell 200 is in direct contact with the liquid cooling plate through a layer of PET blue film, achieving large-area unobstructed bonding. The contact thermal resistance is reduced by more than 40%, which greatly improves the heat exchange efficiency. The operating temperature difference of the individual cell 200 can be controlled within ±2℃, significantly improving the consistency of the entire battery pack, further extending the cell cycle life, and reducing the system's thermal management energy consumption.

[0172] Through multi-dimensional gap design, full-dimensional adaptation of assembly, potting, and buffering is achieved. By limiting the range of each gap, on the one hand, the assembly difficulty of individual battery cells 200 is significantly reduced, and the assembly efficiency is improved by more than 30%. At the same time, it provides a uniform filling channel for the foam, ensuring that the foam is filled without dead corners or air bubbles, and the filling consistency is 100%. On the other hand, it provides sufficient buffer space for the expansion of individual battery cells 200 throughout their entire life cycle, avoiding structural failure caused by the expansion and compression of individual battery cells 200. At the same time, it adapts to the dimensional tolerances of individual battery cells 200, greatly improving the product yield.

[0173] The fully integrated FPC-type CCS module 8 is perfectly compatible with the expansion beam-free housing 1 structure, achieving integrated high-voltage connection and signal acquisition without the need for additional fixing brackets, improving assembly efficiency by over 50%. The FPC acquisition solution can accommodate the expansion displacement of individual battery cells 200, avoiding the problem of traditional wire harnesses breaking under pressure, significantly improving signal acquisition stability. At the same time, the bracket 81 provides full-range insulation protection, significantly improving high-voltage insulation reliability. Laser welding technology achieves low-impedance connection between the aluminum busbar 82 and the pole, with conductivity and connection reliability significantly superior to traditional bolt connection solutions.

[0174] The entire housing is manufactured using sheet metal stamping and bending processes, with full fillet welds at the joints. This eliminates complex machining steps, resulting in low mold investment, high production efficiency, and perfect suitability for large-scale mass production. The highly integrated assembly process reduces production cycle time by over 50%, significantly decreasing production turnover steps and lowering production line investment and manufacturing costs.

[0175] According to the second aspect of this disclosure, such as Figure 6As shown, a method for assembling a battery pack 100 is provided, applicable to the battery pack 100 as described in the foregoing embodiments. The assembly method includes: S610. A tooling 7 is provided, on which a membrane material 6 is laid, wherein the membrane material 6 includes an adhesive backing layer 61 and a release film layer 62, and the release film layer 62 is attached to the tooling 7. S620. Place box 1 on fixture 7; S630. At least two individual battery cells 200 are stacked in the housing 1 along the second direction, and at least two individual battery cells 200 are bonded to the adhesive layer 61. S640, Inject expanding foam into the housing 1; S650. After the foam has cured, the CCS module 8 is hoisted onto the top of the individual cell 200, and the aluminum busbar 82 of the CCS module 8 is welded to the terminal post of the individual cell 200 to form an intermediate component. S660. Hoist the intermediate component onto the liquid cooling plate and connect the housing 1 and the liquid cooling plate using fasteners.

[0176] Understandably, after placing the housing 1 on the fixture 7, the fixture 7 can seal the bottom of the housing 1, allowing the bottom of the individual battery cell 200 to directly contact the membrane material 6 when placed inside the housing 1. Foam is injected into the housing 1, and after curing, a flexible layer 5 is formed. The flexible layer 5 can absorb the expansion force of the individual battery cell 200 through its own elastic strain. Combined with the housing 1, it forms a dual expansion force management system of rigid housing 1 constraint + elastic colloid buffer, effectively constraining the full-cycle expansion deformation of the battery cell and preventing excessive structural deformation failure. After curing, the CCS module 8 is hoisted, and the aluminum busbar 82 of the CCS module 8 is welded to the terminal post of the individual battery cell 200, thus forming an intermediate component with the housing 1, individual battery cell 200, CCS module 8, flexible layer 5, and release film layer 62. The intermediate component is hoisted to separate the back adhesive layer 61 from the release film layer 62, and then assembled onto the liquid cooling plate to achieve the forming of the battery pack 100.

[0177] By using the above assembly method to form the battery pack 100, the three core processes of stacking, potting and curing, and insulation mounting of the individual cells 200 can be integrated into the same workstation, reducing the production cycle by more than 50%, significantly reducing the types of materials and turnover, and lowering production line investment and management costs.

[0178] After the foaming adhesive has cured, the housing 1 is lifted and the backing layer 61 (which can be used as the insulating film 9) is separated from the release film layer 62, thus forming an integrated curing and mounting design. At the same time as the lifting and separation, the blue film at the bottom of the individual battery cell 200 is mounted, which solves the problem of difficult and inconsistent bottom insulation assembly of the individual battery cell 200 in the open housing 1. The insulation protection can reach 100% of Gree's standards. At the same time, the blue film is flat and wrinkle-free, and does not affect the heat conduction between the individual battery cell 200 and the liquid cooling plate.

[0179] It should be noted that when the adhesive layer 61 itself is insulating, it directly serves as the insulating film 9. When the adhesive layer 61 is not insulating, there is an insulating film 9 between it and the release film layer 62. When the adhesive layer 61 separates from the release film layer 62, the insulating film 9 adheres to the adhesive layer 61 and separates from the release film layer 62 together with the adhesive layer 61.

[0180] like Figure 5 As shown, in some embodiments, the tooling 7 is configured as a flat plate, and the tooling 7 is made of 3003 aluminum alloy, which has the advantages of being lightweight and easy to form. The tooling 7 can be reused, further reducing mass production costs.

[0181] In some embodiments, the flatness of the tooling 7 is less than or equal to 0.2 mm, exhibiting extremely high flatness. This allows for the simultaneous flattening of the bottom of the individual battery cell 200 during assembly, ensuring that after the liquid cooling plate is assembled, the individual battery cell 200 can fully adhere to the liquid cooling plate through the backing adhesive layer 61 and the thermally conductive adhesive layer, further optimizing the thermal management effect.

[0182] In some embodiments, the tooling 7 is further provided with transfer grippers at both ends, so that operators can insert their hands or transfer mechanisms into the transfer grippers to move the tooling 7. This enables manual / automatic transfer, assembly, and disassembly of the tooling 7, adapting to the needs of the entire production line operation. The transfer grippers can be designed in a waist shape, ensuring that hands and transfer mechanisms can be inserted into them; the shape and size of the transfer grippers are not limited in this embodiment.

[0183] Please continue reading. Figure 5 In some embodiments, the tooling 7 is provided with a first positioning hole 71, and the release film layer 62 is provided with a second positioning hole 63. Laying the film material 6 on the tooling 7 includes: The membrane material 6 is laid on the tooling 7, and the first positioning hole 71 is aligned with the second positioning hole 63. Positioning plugs 73 are inserted through the first positioning hole 71 and the second positioning hole 63 to fix the release film layer 62 and the tooling 7.

[0184] Understandably, by using the positioning plug 73 inserted through the first positioning hole 71 and the second positioning hole 63, precise positioning between the film material 6 and the tooling 7 can be achieved, and the release film layer 62 can be fixed to the tooling 7. When the housing 1 is lifted after the potting compound has cured, the release film layer 62 will not be lifted along with the adhesive backing layer 61; the release film layer 62 will still adhere to the tooling 7, thereby achieving rapid separation of the adhesive backing layer 61 from the tooling 7. This avoids the problem of the release film layer 62 being lifted along with the adhesive backing layer 61 during lifting and prevents smooth detachment, ensuring that during lifting and separation, the release film layer 62 adheres to the tooling 7, and the adhesive backing layer 61 is completely adhered to the bottom of the individual battery cell 200, simultaneously completing insulation protection and rapid separation of the tooling 7. Since the adhesive backing layer 61 of the PET blue film can provide insulation protection for the bottom of the individual battery cell 200 after lifting and separation, there is no need to separately apply the blue film.

[0185] Based on the standardized positioning design of tooling 7 and membrane material 6, and the positioning of membrane material 6 with housing 1, tooling 7 can be adapted to housing 1 of different specifications, can be reused, further reduce production line adaptation costs, and can be promoted to energy storage battery products of different capacities and sizes.

[0186] Please continue reading. Figure 5 In some embodiments, the tooling 7 is provided with a locking hole 72. Before the step of placing the housing 1 on the tooling 7, the assembly method further includes: Fixture 7 to the lifting frame using the locking hole 72.

[0187] It is understandable that the tooling 7 is fixed to the stand using the locking hole 72, thereby ensuring the stability of the tooling 7 position during the assembly process, so that the position of the tooling 7 does not shift during the assembly and packaging of the single cell 200, and avoiding displacement deviation.

[0188] In some embodiments, the fixture 7 is provided with a plurality of locking holes 72, which are located near the edge of the fixture 7 and are spaced apart circumferentially along the fixture 7. The fixture 7 can be fixed to the lifting frame by passing bolts through the locking holes 72.

[0189] The fixture 7 is first fixed to the lifting frame, and then a lifting tool is used to lift and place the open box 1 onto the surface of the fixture 7 to close the bottom opening of the mounting cavity 11. Thus, the box 1 forms a mounting cavity 11 that is open at the top and sealed at the bottom.

[0190] In some embodiments, the housing 1 is connected to a connector 19, the connector 19 having a connection hole 191, and the membrane material 6 having a third positioning hole 64. Placing the housing 1 on the fixture 7 includes: Place the housing 1 on the fixture 7, and align the connecting hole 191 with the third positioning hole 64; Positioning pins 74 are inserted through the connecting hole 191 and the third positioning hole 64 to position and connect the membrane material 6 to the housing 1.

[0191] It is understandable that the positioning pin 74 passes through the connecting hole 191 of the connector 19 and the third positioning hole 64 of the membrane material 6 to achieve precise positioning of the membrane material 6. Since the membrane material 6 and the tooling 7 are also positioned and fixed by the positioning plug 73, the precise positioning and fixing of the membrane material 6, the tooling 7 and the box 1 can be achieved, ensuring that the membrane material 6 is wrinkle-free and has no offset.

[0192] In the assembly method of this application embodiment, the end plate, steel strip and other structures of the battery module are eliminated, and the internal expansion beam design in the conventional CTP solution is abandoned. The high bending strength integrated box 1 undertakes the function of constraining the expansion force of the single cell 200 throughout the entire life cycle, and is equipped with a special potting glue curing tool 7 to realize the integrated assembly of single cell 200 stacking, potting glue curing and bottom insulation protection of single cell 200, and realize the full-dimensional optimization of structure, thermal management, insulation and assembly.

[0193] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0194] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0195] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0196] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A battery pack (100), characterized in that, include: The housing (1) has an installation cavity (11) inside it, the installation cavity (11) extends through the housing (1) in a first direction, and the housing (1) has a reinforcing member (2) on the end face of each of the opposite ends in a second direction, the reinforcing member (2) extending in a third direction; A single battery cell (200) is disposed in the mounting cavity (11), and at least two single battery cells (200) are provided, and the at least two single battery cells (200) are stacked in the mounting cavity (11) along the second direction; A flexible layer (5) is disposed in the mounting cavity (11), and the flexible layer (5) is located between the single cell (200) and the box wall of the box (1); Wherein, each of the first direction, the second direction and the third direction is set at an angle.

2. The battery pack (100) according to claim 1, characterized in that, Along the third direction, there is a first gap between the single cell (200) and the wall of the housing (1), the first gap being configured to accommodate at least a portion of the flexible layer (5), wherein the width of the first gap is D1, satisfying: 4 mm ≤ D1 ≤ 10 mm.

3. The battery pack (100) according to claim 1, characterized in that, Along the second direction, there is a second gap between the single cell (200) and the wall of the housing (1), the second gap being configured to accommodate at least a portion of the flexible layer (5), wherein the width of the second gap is D2, satisfying: 5 mm ≤ D1 ≤ 25 mm.

4. The battery pack (100) according to claim 1, characterized in that, Along the second direction, there is a third gap between each two adjacent individual cells (200), the third gap being configured to accommodate a buffer pad, wherein the width of the third gap is D3, satisfying: 1 mm ≤ D3 ≤ 6 mm.

5. The battery pack (100) according to claim 1, characterized in that, The battery pack (100) also includes: A liquid cooling plate is detachably connected to the bottom of the housing (1) and closes one side of the mounting cavity (11).

6. The battery pack (100) according to claim 5, characterized in that, The battery pack (100) also includes: An insulating film (9) is disposed between the liquid cooling plate and the single battery cell (200).

7. The battery pack (100) according to claim 6, characterized in that, Along the second direction, the insulating film (9) includes a first fold portion protruding from the housing (1), the first fold portion being configured to adhere to the outer surface of the housing (1) after folding, the width of the first fold portion being D4, satisfying: 5 mm ≤ D4 ≤ 10 mm; and / or, along the third direction, the insulating film (9) includes a second fold portion protruding from the housing (1), the second fold portion being configured to adhere to the outer surface of the housing (1) after folding, the width of the second fold portion being D5, satisfying: 5 mm ≤ D5 ≤ 10 mm.

8. The battery pack (100) according to claim 1, characterized in that, The battery pack (100) also includes: The CCS component (8) is located inside the housing (1) and connected to the individual battery cell (200); Wherein, along the third direction, the distance between the side of the single cell (200) and the side of the CCS assembly (8) is D6, which satisfies: 30 mm ≤ D6 ≤ 80 mm.

9. The battery pack (100) according to claim 8, characterized in that, Along the first direction, the distance between the top surface of the CCS component (8) and the top surface of the housing (1) is D7, which satisfies: 5 mm ≤ D7 ≤ 30 mm.

10. The battery pack (100) according to claim 8, characterized in that, The CCS assembly (8) includes a bracket (81), an aluminum busbar (82), and an FPC acquisition board (83). The aluminum busbar (82) and the FPC acquisition board (83) are both connected to the bracket (81). The aluminum busbar (82) is electrically connected to the FPC acquisition board (83). The aluminum busbar (82) is configured to be welded to the terminal post of the single cell (200).

11. The battery pack (100) according to any one of claims 1 to 10, characterized in that, The reinforcing member (2) is hollow inside, and its longitudinal section is set as one of polygon, circle or ellipse.

12. The battery pack (100) according to any one of claims 1 to 10, characterized in that, The box (1) is an integral structural component.

13. The battery pack (100) according to any one of claims 1 to 10, characterized in that, The housing (1) is also connected to mounting platforms (18) at opposite ends in the second direction, the mounting platforms (18) being configured to connect to the output aluminum busbars of the individual battery cells (200).

14. The battery pack (100) according to any one of claims 1 to 10, characterized in that, The box (1) has a lifting hole (16) and the outer surface of the box (1) has a flange (17) circumferentially disposed in the lifting hole (16).

15. The battery pack (100) according to any one of claims 1 to 10, characterized in that, The reinforcing member (2) is provided in at least two parts, and the at least two reinforcing members (2) are spaced apart along the first direction.

16. The battery pack (100) according to claim 15, characterized in that, The single cell (200) has an axis (4) parallel to the third direction. The reinforcing member (2) is configured as two, namely a first reinforcing member (21) and a second reinforcing member (22), wherein the first reinforcing member (21) and the second reinforcing member (22) are located on opposite sides of the axis (4).

17. The battery pack (100) according to claim 16, characterized in that, The first reinforcing member (21) is located above the second reinforcing member (22). Along the first direction, the distance between the first reinforcing member (21) and the axis (4) is D8, and the distance between the second reinforcing member (22) and the axis (4) is D9, satisfying: D8 > D9.

18. The battery pack (100) according to any one of claims 1 to 10, characterized in that, The thickness of the reinforcing member (2) is D10, which satisfies the following condition: 1 mm ≤ D10 ≤ 2 mm.

19. A method for assembling a battery pack (100), characterized in that, The assembly method, applied to the battery pack (100) as described in any one of claims 1 to 18, comprises: A tooling (7) is provided, on which a membrane material (6) is laid, wherein the membrane material (6) includes an adhesive backing layer (61) and a release film layer (62), and the release film layer (62) is attached to the tooling (7). Place the box (1) on the tooling (7); At least two of the individual battery cells (200) are stacked in the housing (1) along the second direction, and at least two of the individual battery cells (200) are bonded to the adhesive layer (61); Inject expanding foam into the box (1); After the foaming adhesive has cured, the CCS assembly (8) is hoisted to the top of the single cell (200), and the aluminum busbar (82) of the CCS assembly (8) is welded to the electrode post of the single cell (200) to form an intermediate component; The intermediate component is hoisted onto the liquid cooling plate, and the housing (1) and the liquid cooling plate are connected using fasteners.

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