Battery cell stack structure and battery pack

Abstract

The utility model discloses a kind of electric core stacking structure and battery pack, comprising: a plurality of electric core, parallel and interval setting along preset direction;A plurality of buffer, each buffer is clamped between two adjacent electric cores, and common formation electric core stack;Fastening ring, the end portion outer periphery of electric core stack is sleeved, for when electric core stack is in pre-tightening state, it is constrained to its exertion force.The application realizes the effective pre-tightening force control of electric core stacking direction, ensures that the connecting piece welding procedure can be reliably completed before module into box.Elastic constraint structure replaces traditional rigid limiting piece, reduces module assembly complexity.Dynamic pressure compensation mechanism adapts to the volume change in the process of electric core charging and discharging, prolongs battery cycle life.Compound constraint system improves module overall stiffness, enhances battery package anti-vibration impact performance.

Description

Technical Field

[0001] This utility model relates to the field of power battery technology for new energy vehicles, and in particular to a cell stacking structure and battery pack. Background Technology

[0002] With the rapid development of the new energy industry, blade batteries occupy an important position in the battery cell market. In applications where space is limited along the length of the battery pack, traditional technologies typically employ steel strip module solutions or cell stacking techniques. In existing technologies, cells are bonded together with aerogel to form modules, and the modules are connected to the battery housing using thermally conductive structural adhesive. While this structure can ensure the basic functions of the battery pack, it has significant technical drawbacks.

[0003] First, existing solutions cannot achieve pre-tightening force during battery pack placement, resulting in lower battery pack energy density and higher costs. Due to the compact Y-axis dimensions of the battery pack, the cell welding connection operations cannot be completed inside the pack; they must be performed after the modules are stacked externally before placement into the pack. This process limitation prevents the application of pre-tightening force to the modules, directly impacting battery lifespan and energy density performance.

[0004] Secondly, in existing technologies, the buffer material between battery cells undergoes almost no compression, resulting in a lack of pre-tightening force in the stacking direction. The module's fixation relies entirely on adhesive bonding, leading to a low overall modality of the battery pack and insufficient structural strength and stiffness. This design makes it difficult to guarantee long-term stable structural performance during vehicle operation.

[0005] Furthermore, traditional solutions require pressure strips on the top of the module and adhesive-limiting strips on the bottom, increasing material costs and structural complexity. Achieving a high-energy-density, high-structural-strength blade battery CTP structure within a limited space has become a pressing technical challenge for the industry. Summary of the Invention

[0006] In view of this, the present invention provides a cell stacking structure, which has the advantages of improving the energy density of the battery pack, enhancing the structural strength and simplifying the assembly process.

[0007] To achieve the above objectives, this utility model provides the following technical solution: A battery cell stacking structure includes: a plurality of battery cells arranged parallel to each other and spaced apart along a preset direction; a plurality of buffer members, each buffer member being sandwiched between two adjacent battery cells to form a battery cell stack; and a fastening ring, fitted around the outer periphery of the end of the battery cell stack, for applying a constraint force to the battery cell stack when it is in a pre-tightened state.

[0008] Preferably, the cell stack structure further includes a plurality of connecting pieces, which are disposed at the ends of the cell stack and fixedly connected to the electrodes of the plurality of cells to enable electrical connection between the plurality of cells.

[0009] Preferably, the width of the fastening ring is 1-2 cm; the thickness of the fastening ring is 0.5-3 mm.

[0010] Preferably, the fastening ring can be a plastic ring or a steel ring.

[0011] Preferably, the buffer can be silicone foam, synthetic rubber foam, polyurethane foam, or composite partition.

[0012] Preferably, the thickness of the buffer is 0.5-3mm.

[0013] Preferably, the cell stacking structure further includes vacuum foam, with two pieces of vacuum foam respectively installed at both ends of the length direction of the cell stack.

[0014] Preferably, the vacuum foam is attached to the battery cell stack by adhesive bonding.

[0015] This utility model also proposes a battery pack, including the cell stacking structure and the battery pack housing as described in any of the above embodiments, wherein the cell stacking structure is installed inside the battery pack housing.

[0016] Preferably, the terminals of the battery cell are located at both ends along its length, and the upper end of the terminal of the battery cell is located below the top of the top wall of the battery pack housing.

[0017] The beneficial effects of this utility model are as follows: Compared with the prior art, this application achieves effective pre-tightening force control in the cell stacking direction, ensuring that the welding process of the connecting pieces is reliably completed before the module is placed into the box. An elastic constraint structure replaces traditional rigid limiting components, reducing the complexity of module assembly. A dynamic pressure compensation mechanism adapts to volume changes during cell charging and discharging, extending the battery cycle life. The composite constraint system improves the overall rigidity of the module and enhances the battery pack's resistance to vibration and shock.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the cell stacking structure of this utility model; Figure 2 This is a schematic diagram of the cell stacking structure (without the battery box) of this utility model; Figure 3 This is a top view of the cell stacking structure of this utility model; Figure 4 yes Figure 3 Sectional view of line AA in the middle; Figure 5 yes Figure 4 A magnified view of region B in the middle.

[0020] Figure label: 1. Battery pack housing; 2. Cell stack; 201. Cell; 202. Buffer component; 3. Fastening rings; 4. Vacuum-sealed foam. Detailed Implementation

[0021] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0022] Furthermore, 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] The following is for reference. Figures 1 to 5 The cell stacking structure in the embodiments of this utility model is described.

[0024] This application discloses a battery cell stacking structure, comprising: a plurality of battery cells 201 arranged parallel to each other and spaced apart along a preset direction; a plurality of buffer members 202, each buffer member 202 sandwiched between two adjacent battery cells 201, together forming a battery cell stack body 2; and a fastening ring 3 sleeved on the outer periphery of the end of the battery cell stack body 2, used to apply a restraining force to the battery cell stack body 2 when it is in a pre-tightened state. Further, the battery cell stacking structure also includes a plurality of connecting pieces, which are disposed at the ends of the battery cell stack body 2 and fixedly connected to the electrodes of the plurality of battery cells 201, so that the plurality of battery cells 201 are electrically connected.

[0025] Among them, the buffer 202 refers to a layer of elastic material with compressible properties, with a thickness of 0.5-3mm, specifically such as silicone foam, synthetic rubber foam, polyurethane foam, composite separator, etc., which allows for overpressure deformation during the stacking of battery cells 201. The fastening ring 3 refers to an annular elastic constraint component, specifically such as a plastic ring or a steel ring, whose inner diameter is smaller than the total thickness in the width direction of the battery cell stack 2, and generates radial clamping force through elastic deformation.

[0026] Specifically, the battery cells 201 and buffer components 202 are alternately stacked to form a compressible layered structure, completing the initial assembly under overpressure applied by the external tooling. Before the tooling is removed, the fastening rings 3 are fitted onto both ends of the module, utilizing the material's springback properties to generate a continuous radial constraint force. This constraint force counteracts the springback tendency of the battery cell stack gaps, maintaining the minimum electrode spacing required for welding the battery cell 201 electrode connection pieces. The annular closed structure of the fastening rings 3 creates a uniform circumferential pressure distribution, preventing deformation of the battery cell 201 shell caused by localized stress concentration. The buffer components 202 store elastic potential energy under compressed conditions, compensating for dimensional changes caused by the expansion differences of the battery cells 201.

[0027] Compared to existing technologies, traditional solutions rely on adhesive bonding and cannot achieve active clamping, while this solution achieves dynamic pressure maintenance through an elastic constraint structure. Existing technologies require separate pressure strips and adhesive limiting strips, while this solution integrates limiting and isolation functions using the fastening ring 3, reducing the number of assembly parts. Traditional methods cannot apply additional pre-tightening force after the module is placed in the box; this solution uses a compressible buffer layer in conjunction with the elastic constraint ring to form an adaptive clamping and holding mechanism.

[0028] Through the above technical solutions, this application achieves effective pre-tightening force control in the stacking direction of the battery cells 201, ensuring that the welding process of the connecting pieces is reliably completed before the module is placed into the casing. An elastic constraint structure replaces traditional rigid limiting components, reducing the complexity of module assembly. A dynamic pressure compensation mechanism adapts to the volume changes of the battery cells 201 during charging and discharging, extending the battery's cycle life. The composite constraint system improves the overall rigidity of the module and enhances the battery pack's resistance to vibration and shock.

[0029] In some embodiments, the width of the fastening ring 3 is 1-2 cm. The width of the fastening ring 3 refers to the lateral dimension of the annular structure extending along the length of the cell stack 2.

[0030] Specifically, the fastening ring 3 applies radial constraint force to the cell stack 2 through its annular wrapping structure in the width direction, and its contact area forms a continuous fit with the side of the cell stack 2. This width range allows the fastening ring 3 to compensate for the gaps caused by the expansion of the cell 201 through its own elastic deformation when replacing traditional pressure strips and adhesive strips, while also preventing the effective space inside the battery pack from being compressed due to excessive size.

[0031] Through the above technical solution, this application achieves stable transmission of module preload within a limited space, solving the space waste problem caused by the stacking of multiple components in traditional solutions. At the same time, structural integration reduces material consumption and assembly process complexity, thereby simultaneously optimizing the compactness of the battery pack's internal layout and manufacturing cost control.

[0032] In some embodiments, the thickness of the fastening ring 3 is 0.5-3mm. Specifically, when fastening rings 3 with a thickness of 0.5-3mm are fitted at both ends of the module in the width direction, this thickness range allows the fastening ring 3 to form an effective constraint interface within the limited installation space. After the preload applied by the tooling is removed, the fastening ring 3 continues to press the stack of battery cells 201 with elastic restoring force, preventing the spacing caused by the expansion of battery cells 201 from increasing. At the same time, this thickness design gives the fastening ring 3 both bending stiffness and flexible fitting characteristics. It can replace the metal pressure strip set separately in the traditional module to resist top deformation, and it can also replace the bottom limiting strip to control the thickness of thermally conductive adhesive, realizing the integration of multiple functions in a single component.

[0033] Through the above technical solution, this application can establish a stable pre-tightening constraint system before the module is placed into the box, ensuring the reliability of the welding structure of the battery cell 201. At the same time, the use of independent limiting components is reduced through structural integration, thereby reducing material costs and assembly complexity. The elastic constraint characteristics of the fastening ring 3 effectively suppress the deformation and displacement of the battery cell 201 under working conditions, improve the overall structural rigidity of the module, and avoid the risk of connection failure due to vibration.

[0034] In some embodiments, for example Figure 2 and Figure 5 As shown, the cell stacking structure also includes vacuum-sealed foam 4, with two pieces of vacuum-sealed foam 4 respectively installed at both ends of the cell stack 2 along its length. The vacuum-sealed foam 4 refers to an elastic material that has undergone vacuum compression and is sealed in a package. After the vacuum is released, it expands by absorbing air, forming a hardened support structure. During installation, the vacuum-sealed foam 4 is in a compressed state, coated with a pressure-sensitive adhesive layer on one side, and fixed to the ends of the cell stack 2 by adhesive bonding. This feature, through the reaction force generated by expansion, continuously constrains the longitudinal deformation of the cell stack 2, thereby maintaining the stability of the spacing between the cells 201. The vacuum-sealed foam 4 is installed on the cell stack 2 by adhesive bonding.

[0035] Specifically, before the module is placed into the housing, two pieces of vacuum-sealed foam 4 are respectively bonded to both ends of the cell stack 2 along its length. After placement into the housing, the sealed packaging of the foam is punctured to expose it to air. At this time, the foam absorbs air, expands, and hardens, generating an expansion force perpendicular to the stacking direction of the cell 201. This expansion force replaces the clamping force of traditional tooling and continuously acts on both ends of the cell stack 2, counteracting the displacement tendency of the cell 201 caused by temperature changes or mechanical vibration, and avoiding the risk of breakage at the welded joint of the cell 201 terminal connecting piece due to changes in the spacing of the cell 201. At the same time, the bonding installation method of the vacuum-sealed foam 4 simplifies the connection process between the module and the housing, eliminating the need for additional pressure strips or adhesive limiting strips.

[0036] Compared to existing technologies, traditional solutions rely on external tooling to clamp the module directly into the housing. However, once the tooling is removed, it cannot continuously provide constraint, causing the gap between the 201 cells to spring back. This solution, however, utilizes the self-expanding properties of the vacuum-sealed foam 4 to continuously apply pre-tightening force after the module is placed in the housing, without requiring the retention of tooling structures. Furthermore, traditional modules require separate pressure strips and adhesive-limiting strips to maintain structural stability; this solution integrates directly into the module end through the dual action of foam expansion and adhesive fixation, reducing the number of components.

[0037] Through the above technical solution, this application effectively solves the problem of the pre-tightening force not being able to be maintained continuously after the module is placed in the box, ensuring the stability of the spacing between the 201 cells and avoiding the risk of welding failure. At the same time, by simplifying the module fixing structure, production costs are reduced and assembly efficiency is improved. The expansion hardening characteristics of the vacuum foam 4 further enhance the module's vibration resistance within the box, improving the overall structural reliability.

[0038] In some embodiments, the thickness of the vacuum-sealed foam 4 is greater than or equal to 6.4 mm. Specifically, during the module insertion process, the vacuum-sealed foam 4 is designed to expand to a preset thickness after the vacuum is released and generate a continuous force through compression deformation. When the initial thickness of the foam is set to 6.4 mm, it expands to this thickness after absorbing air, and then compresses to the target deformation under the theoretical gap constraint between the module and the housing. This compression process results in a uniform stress distribution inside the foam, thereby forming a stable constraint force on both sides of the module. This thickness is selected based on the compressive stress characteristic curve of the foam material to ensure that sufficient pressure is provided when the target compression ratio is reached to counteract the deformation trend of the battery cells 201 inside the module, thereby maintaining the stability of the spacing between the battery cells 201.

[0039] Through the above technical solution, this application achieves automatic maintenance of pre-tightening force through the compression deformation of foam after the module is placed in the box, effectively replacing the clamping function of tooling and ensuring the long-term stability of the 201 cell stacking structure. At the same time, this thickness design avoids stress relaxation or local deformation caused by excessive compression of foam material, so that the module can still maintain a uniform stress state under dynamic working conditions, thereby improving the overall structural strength and service life of the battery pack.

[0040] This utility model also proposes a battery pack, including the cell stacking structure described in any of the above embodiments and the battery pack housing 1. The cell stacking structure is installed inside the battery pack housing 1. By setting the above-mentioned cell stacking structure, the problems of low energy density and insufficient structural strength caused by the lack of pre-tightening force in the cell stacking 201 are effectively solved. The cell stacking structure is installed in the housing with pre-tightening force in a limited space, which extends the service life of the cell 201, improves the overall modal and mechanical stability of the battery pack, and reduces the manufacturing cost through component functional integration.

[0041] In some embodiments, for example Figure 1 The terminals of the battery cell 201 are located at both ends along its length, and the upper end of the terminal of the battery cell 201 is located on the lower side of the top of the battery pack housing 1.

[0042] The cell stacking structure and other components and operations of the battery pack according to the embodiments of this utility model are known to those skilled in the art and will not be described in detail here.

[0043] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0044] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A cell stacking structure, characterized in that, include: Several battery cells are arranged parallel and spaced apart along a preset direction; Several buffer components, each of which is sandwiched between two adjacent battery cells, together forming a battery cell stack; A fastening ring is fitted around the outer periphery of the end of the battery cell stack and is used to apply a restraining force to the battery cell stack when it is in a pre-tightened state.

2. The cell stacking structure according to claim 1, characterized in that, The cell stack structure also includes multiple connecting pieces, which are disposed at the ends of the cell stack and fixedly connected to the electrodes of the multiple cells to enable electrical connection between the multiple cells.

3. The cell stacking structure according to claim 1, characterized in that, The width of the fastening ring is 1-2 cm; the thickness of the fastening ring is 0.5-3 mm.

4. The cell stacking structure according to claim 1, characterized in that, The fastening ring can be a plastic ring or a steel ring.

5. The cell stacking structure according to claim 1, characterized in that, The buffer is a layer of elastic material with compressible properties.

6. The cell stacking structure according to claim 1, characterized in that, The thickness of the buffer is 0.5-3mm.

7. The cell stacking structure according to claim 1, characterized in that, It also includes vacuum foam, with two pieces of vacuum foam respectively installed at both ends of the length direction of the battery cell stack.

8. The cell stacking structure according to claim 7, characterized in that, The vacuum-sealed foam is attached to the battery cell stack by adhesive bonding.

9. A battery pack, characterized in that, The battery pack includes the cell stacking structure and battery pack housing as described in any one of claims 1-8, wherein the cell stacking structure is installed in the battery pack housing.

10. The battery pack according to claim 9, characterized in that, The terminals of the battery cell are located at both ends along its length, and the upper end of the battery cell terminals is located below the top of the battery pack housing.

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