Battery cell, battery pack, and vehicle

Abstract

The utility model discloses related to the technical field of power battery, and discloses a kind of electric core, battery pack and vehicle, the electric core includes electric core monomer and isolation layer, the isolation layer is covered in the electric core monomer top surface, the isolation layer is equipped with through-hole in the area corresponding with electric core monomer top surface shoulder, and the through-hole is filled with structure glue for being connected with the pressing strip;The electric core top surface shoulder is equipped with a protrusion in one of the pressing strip, and the other is equipped with the recess that is matched with the protrusion, and the protrusion passes through the through-hole and extends into the recess. The technical scheme of the utility model can improve the connection strength of electric core monomer and pressing strip.

Description

Technical Field

[0001] This utility model relates to the field of power battery technology, specifically to a battery cell, a battery pack, and a vehicle. Background Technology

[0002] During the assembly and fixing of battery cells, to ensure a stable connection between the cell and the external structure and to guarantee electrical safety, the top surface of the cell is usually covered with an insulating layer for electrical isolation and protection. When it is necessary to connect the shoulder of the individual cell to the pressure strip, the industry standard solution is to create a large through-hole in the insulating layer. Structural adhesive is then applied inside the through-hole to bond and fix the pressure strip to the cell. In other words, the through-hole exposes the individual cell, allowing the structural adhesive to directly act on it to form a connection.

[0003] The above-mentioned conventional solutions have significant technical limitations: on the one hand, the through-hole area is limited by the structure of the battery cell itself, and the electrode layout and tab lead-out structure on the top of the battery cell will compress the effective area where through-holes can be opened; on the other hand, the insulating isolation layer needs to maintain its own structural strength to ensure insulation performance, and large-area openings will lead to a decrease in the mechanical stability of the isolation layer, so the through-hole area cannot be expanded indefinitely.

[0004] This limitation directly results in insufficient effective contact area between the structural adhesive and the individual battery cells, making it difficult to meet the bonding strength requirements of actual use. Under conditions such as vibration and impact during battery factory testing and actual applications, the weak bonding structure is prone to loosening, which not only reduces the stability of the battery cell fixation but may also exacerbate stress concentration at the connection points of the battery cell busbar components, and even cause safety hazards such as damage to the insulation layer. At the same time, it limits the optimization space of the battery pack in terms of lightweighting and high energy density. Utility Model Content

[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide a battery cell, battery pack and vehicle that can improve the connection strength between the battery cell and the pressure strip.

[0006] In a first aspect, embodiments of this application provide a battery cell, including a battery cell unit and an insulating layer. The insulating layer is disposed on the top surface of the battery cell unit. The insulating layer has a through hole in a region corresponding to the shoulder of the top surface of the battery cell unit. The through hole is filled with structural adhesive for connection with a pressure strip. One of the shoulder of the top surface of the battery cell unit and the pressure strip has a protrusion, and the other has a groove adapted to the protrusion. The protrusion extends through the through hole into the groove.

[0007] In this embodiment, after the protrusion extends into the groove through the through hole, it increases the contact area between the structural adhesive and the battery cell and pressure strip, forming an adhesive surface on both the side of the protrusion and the inner wall of the groove. Furthermore, the protrusion's positioning guides the structural adhesive to fill the through hole and groove evenly, preventing localized thinness or air bubbles, significantly improving the adhesive's load-bearing capacity. This effectively solves the problem of insufficient bonding strength in traditional solutions due to limited through hole area, maintaining a stable connection even under vibration and impact conditions. Moreover, since the protrusion and groove structure helps improve bonding strength, there is no need to increase the contact area of ​​the structural adhesive by enlarging the through hole area. Therefore, the through hole size can be controlled to the minimum necessary range for the protrusion to pass through and the structural adhesive to fill, maximizing the preservation of the complete coverage area of ​​the insulation layer. Simultaneously, small through holes reduce the mechanical weaknesses of the insulation layer, avoiding the deformation and breakage risks caused by large openings in traditional solutions. This ensures the continuous electrical isolation function, reducing the risk of short circuits between the battery cell tabs, electrodes, and external pressure strips, while maintaining the protective performance of the insulation layer on the top surface of the battery cell.

[0008] In one embodiment, the sidewall of the groove or the side of the protrusion is provided with glue storage grooves distributed in a grid pattern.

[0009] In one embodiment, the sidewall of the groove or the side of the protrusion is provided with raised strips distributed in a grid pattern.

[0010] In one embodiment, the orthographic projection of the through hole on the top surface of the battery cell overlaps the orthographic projection of the groove on the top surface of the battery cell.

[0011] In one embodiment, the top surface of the battery cell has a groove, and the bottom surface of the pressure strip has a protrusion that fits into the groove.

[0012] In one embodiment, the roughness of the groove wall is greater than a preset roughness threshold.

[0013] In one embodiment, the cross-sectional shape of the through hole is rectangular, circular, triangular, or oblong.

[0014] In one embodiment, the projected area of ​​the through hole on the top surface of the battery cell is greater than or equal to a preset area threshold.

[0015] Secondly, embodiments of this application provide a battery pack including the aforementioned battery cells.

[0016] Thirdly, embodiments of this application provide a vehicle including the aforementioned battery pack.

[0017] This utility model has the following beneficial effects: The protrusion of this invention, extending through the through-hole into the groove, increases the contact area between the structural adhesive and the battery cell and pressure strip, forming an adhesive surface on both the side of the protrusion and the inner wall of the groove. Furthermore, the protrusion's positioning guides the structural adhesive to fill the through-hole and groove evenly, preventing localized thinness or air bubbles, significantly improving the adhesive's load-bearing capacity. This effectively solves the problem of insufficient bonding strength in traditional solutions due to limited through-hole area, maintaining a stable connection even under vibration and impact conditions. Moreover, since the protrusion and groove structure helps improve bonding strength, there's no need to increase the contact area of ​​the structural adhesive by enlarging the through-hole area. Therefore, the through-hole size can be controlled to the minimum necessary range for the protrusion to pass through and the structural adhesive to fill, maximizing the preservation of the complete coverage area of ​​the insulation layer. Simultaneously, the small through-hole area reduces the mechanical weaknesses of the insulation layer, avoiding the deformation and breakage risks caused by large openings in traditional solutions. This ensures the continuous electrical isolation function, reducing the risk of short circuits between the battery cell tabs, electrodes, and external pressure strips, while maintaining the protective performance of the insulation layer on the top surface of the battery cell. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application will be described below.

[0019] Figure 1 This is a top view of the battery cell disclosed in the embodiments of this application; Figure 2 This is a cross-sectional schematic diagram of one embodiment of the battery cell disclosed in this application.

[0020] Figure 3 This is a cross-sectional schematic diagram of another embodiment of the battery cell disclosed in this application.

[0021] Figure 4 This is a cross-sectional schematic diagram of another embodiment of the battery cell disclosed in this application.

[0022] Explanation of reference numerals in the attached figures: 1-Battery cell, 2-Insulating layer, 21-Through hole, 3-Pressure strip, 4-Structural adhesive, 5-Groove; 6-Protrusion, 7-Adhesive storage tank, 8-Protrusion strip. Detailed Implementation

[0023] The embodiments of this application are described below with reference to the accompanying drawings.

[0024] See Figure 1 and Figure 2As shown in the figure, this application provides a battery cell, including a battery cell 1 and an insulating layer 2. The insulating layer 2 is disposed on the top surface of the battery cell 1. The insulating layer 2 has a through hole 21 in a region corresponding to the shoulder of the top surface of the battery cell 1. The through hole 21 is filled with structural adhesive 4 for connection with a pressure strip 3. One of the shoulder of the top surface of the battery cell 1 and the pressure strip 3 has a protrusion 6, and the other has a groove 5 adapted to the protrusion 6. The protrusion 6 extends through the through hole 21 into the groove 5.

[0025] In this invention, after the protrusion 6 extends into the groove 5 through the through hole 21, it increases the contact area between the structural adhesive 4 and the battery cell 1 and the pressure strip 3, forming an adhesive surface on both the side of the protrusion 6 and the inner wall of the groove 5. Furthermore, the positioning and guidance of the protrusion 6 ensures that the structural adhesive 4 is evenly filled within the through hole 21 and the groove 5, preventing localized thinness of the adhesive layer or residual air bubbles. This significantly improves the bonding load-bearing capacity and effectively solves the problem of insufficient bonding strength in traditional solutions due to the limited area of ​​the through hole 21. Even under vibration and impact conditions, a stable connection can be maintained. Moreover, since the structure of the protrusion 6 and the groove 5 helps to improve the bonding strength, there is no need to increase the contact area of ​​the structural adhesive 4 by expanding the area of ​​the through hole 21. Therefore, the size of the through hole 21 can be controlled within the minimum necessary range to allow the protrusion 6 to pass through and the structural adhesive 4 to fill, maximizing the preservation of the complete coverage area of ​​the insulating layer 2. Meanwhile, the small-area through-hole 21 can reduce the mechanical weak points of the isolation layer 2, avoid the risk of deformation and breakage of the isolation layer 2 caused by large-area openings in traditional solutions, ensure that it continues to play an electrical isolation role, reduce the short circuit risk between the battery cell tab, electrode and external pressure strip 3, and maintain the protective performance of the isolation layer 2 on the top surface of the battery cell 1.

[0026] As a preferred embodiment of this utility model, see [link to relevant documentation]. Figure 3 As shown, the sidewall of the groove 5 or the side of the protrusion 6 is provided with glue storage grooves 7 distributed in a grid pattern.

[0027] In this embodiment, the mesh-shaped adhesive reservoir 7 further enhances the bonding effect between the protrusions 6 and the grooves 5 by optimizing the adhesive interface morphology. Specifically, the walls and bottom of the reservoir 7 form additional adhesive surfaces. Compared to the smooth sides of the protrusions 6 and grooves 5, the mesh structure increases the actual contact area between the structural adhesive 4 and the protrusions 6 and grooves 5. Furthermore, the interlocking morphology of the reservoir 7 (where the adhesive can be embedded in the groove) creates an interface anchoring effect, significantly reducing the risk of the adhesive layer peeling off from the sides of the protrusions 6 or grooves 5. Compared to a smooth interface, it is more resistant to lateral tensile forces. Moreover, after the structural adhesive 4 cures, the adhesive within the mesh reservoir 7 forms a mesh-shaped support skeleton. This skeleton can disperse the shear and tensile forces borne by the interface, preventing stress concentration on the adhesive surface. This allows the adhesive load to be transferred to a larger area through the mesh skeleton, significantly improving the overall adhesive load-bearing capacity, especially suitable for the dynamic load transfer requirements under long-term vibration conditions of battery packs.

[0028] As a preferred embodiment of this utility model, see [link to relevant documentation]. Figure 4 As shown, the sidewall of the groove 5 or the side of the protrusion 6 is provided with protrusions 8 distributed in a grid pattern.

[0029] In this embodiment, the top and side surfaces of the protrusion 8 can be tightly bonded to the structural adhesive 4, increasing the bonding contact area. At the same time, after the protrusion 8 is embedded in the adhesive layer, it will form an interlaced shape with the cured structural adhesive 4, with the adhesive layer wrapping the protrusion 8, similar to micro anchor points. This can effectively resist lateral peeling force and longitudinal shear force, preventing the adhesive layer from falling off the interface as a whole, which is especially suitable for dynamic load scenarios when the battery pack is subjected to vibration.

[0030] Furthermore, the grid-like protrusions 8 divide the originally continuous single adhesive layer into a composite structure that combines multiple independent adhesive segments with the support of the protrusions 8. The cured adhesive layer is no longer a simple planar adhesive, but rather a synergistic load-bearing system formed by the rigid protrusions and flexible adhesive segments relying on the protrusions 8. When the interface is subjected to external forces, the protrusions 8 can directly bear part of the load, reducing the stress on the adhesive layer alone and preventing the adhesive layer from cracking due to excessive local stress. The overall bonding load-bearing capacity is significantly improved compared to a smooth interface.

[0031] It should be noted that the height of the protrusion 8 can be preset according to design requirements. When the protrusion 6 is fully inserted into the groove 5, a small gap is maintained between the top surface of the protrusion 8 and the side wall of the groove 5 or the side of the protrusion 6.

[0032] As a preferred embodiment of this utility model, see [link to relevant documentation]. Figure 2 As shown, the orthographic projection of the through hole 21 on the top surface of the battery cell 1 covers the orthographic projection of the groove 5 on the top surface of the battery cell 1.

[0033] In this embodiment, the design of the through-hole projection covering the groove 5 essentially sets an upper limit constraint on the size of the groove 5. The maximum size of the groove 5 cannot exceed the size of the through-hole 21; otherwise, it cannot be completely covered by the projection of the through-hole 21. The size of the through-hole 21 itself is designed based on the minimum reasonable range that satisfies the passage of the protrusion 6, the filling of the adhesive, and necessary redundancy, and will not be blindly expanded. This avoids the problem in conventional designs where the groove 5 is blindly enlarged to increase the bonding area, resulting in the edge of the groove 5 being too close to the boundary of the isolation layer 2 and insufficient support area. It ensures that the isolation layer 2 always has a sufficient solid area around the groove 5 as mechanical support, and prevents the isolation layer 2 from being suspended due to the groove 5 being too large.

[0034] In a preferred embodiment of the present invention, the top surface of the battery cell 1 is provided with a groove 5, and the bottom surface of the pressure strip 3 is provided with a protrusion 6 that fits with the groove 5.

[0035] The shoulder of the top surface of the battery cell 1 is an extension area of ​​the battery cell shell, which has high mechanical strength. There is no need to worry about weakening the core structure strength of the battery cell when the groove 5 is opened here. Moreover, the battery cell 1 around the groove 5 can form a stable support, avoiding the problem of the pressure strip 3's strength decreasing due to the conventional deep groove 5 on the pressure strip. This ensures that the groove 5 is not easily deformed or cracked during long-term use.

[0036] As an external connector, the bottom space of the pressure strip 3 is not limited by the internal structure of the battery cell, and the size, height and shape of the protrusion 6 can be flexibly designed according to the requirements. At the same time, the pressure strip 3 is mostly made of plastic or thin metal, and the protrusion 6 can be formed in one step through mature processes such as injection molding (plastic pressure strip) and stamping (metal pressure strip). The processing difficulty is much lower than processing the protrusion 6 on the battery cell 1. Moreover, the protrusion 6 is located on the bottom surface of the pressure strip 3, and can be directly aligned with the shoulder groove 5 of the battery cell 1 during assembly without adjusting the direction of the pressure strip 3, thus improving the ease of assembly.

[0037] In a preferred embodiment of the present invention, the roughness of the groove wall of the groove 5 or the roughness of the side wall of the protrusion 6 is greater than a preset roughness threshold.

[0038] Compared to the smooth groove 5 or the raised sidewall 6, the surface with a roughness greater than the preset threshold has a large number of micro protrusions and depressions. The structural adhesive 4 can penetrate into these micro gaps to form an interlocking structure in which the adhesive layer wraps around the micro protrusions. Compared to the smooth surface, this increases the actual adhesive contact area and directly improves the load-bearing capacity of the adhesive base.

[0039] Furthermore, the cured structural adhesive 4 forms micro-anchors with the microscopic depressions on the rough surface. When the interface is subjected to lateral peeling force or longitudinal shear force, these micro-anchors can prevent the adhesive layer from sliding relative to the substrate, thus preventing the adhesive layer from detaching from the surface as a whole. It is particularly suitable for dynamic loads under battery pack vibration conditions, effectively resisting adhesive layer fatigue peeling and significantly improving bonding reliability.

[0040] In a preferred embodiment of this utility model, the cross-sectional shape of the through hole 21 is rectangular, circular, triangular or oblong.

[0041] Different cross-sectional shapes of through holes 21 can be matched with mature processing methods for the cell separator 2, without the need for additional specialized equipment, balancing efficiency and cost. Circular through holes 21 can be achieved through drilling and punching processes, leaving no sharp corner residue and minimizing cutting damage to the separator 2 material. This is particularly suitable for thinner separators 2, and drilling or punching equipment is industry-standard, offering high processing efficiency and suitability for mass production. Rectangular through holes 21 can be processed through milling and die-cutting processes, precisely matching square protrusions 6, such as the rectangular protrusions 6 on the bottom of the pressure strip 3, maximizing the mating area between the protrusions 6 and the through hole 21, and improving bonding stability. Oval (elongated oval) through holes 21 can be processed through stamping combined with trimming processes. Their long axis extension can accommodate protrusions 6 that require positional adjustments along a specific direction, meeting assembly requirements without increasing the overall area of ​​the through hole 21. Triangular through holes 21 are suitable for scenarios with extremely limited space, using sharp angles to reduce the area occupied by the through hole 21 on the effective area of ​​the separator 2.

[0042] In a preferred embodiment of the present invention, the projected area of ​​the through hole 21 on the top surface of the battery cell 1 is greater than or equal to a preset area threshold.

[0043] If the projected area of ​​the through hole 21 is too small (smaller than the cross-sectional projection of the protrusion), it will cause rigid friction between the protrusion 6 and the edge of the through hole 21 when the protrusion 6 is inserted. This can result in minor scratches on the protrusion 6 and the edge of the through hole 21, affecting the adhesive seal, or even cause the protrusion 6 to break or the isolation layer 2 to tear, directly leading to connection failure. However, an area design greater than or equal to the preset threshold can ensure that the protrusion 6 can be smoothly inserted along the axis of the through hole 21 without forced compression, thus protecting the structural integrity of the protrusion 6 and the isolation layer 2.

[0044] It should be noted that the preset area threshold needs to be set reasonably in conjunction with the amount of adhesive required to ensure that the through hole can hold enough adhesive so that the adhesive can completely cover the raised side and fill the transition area between the through hole and the groove, thus avoiding insufficient bonding strength due to insufficient adhesive.

[0045] In one embodiment, this application also provides a battery pack including the battery cells described in any of the above embodiments.

[0046] In one embodiment, this application also provides a vehicle including the battery pack described in the above embodiments.

[0047] The vehicles mentioned can be, but are not limited to, pure electric vehicles (PEV / BEV), hybrid electric vehicles (HEV), range-extended electric vehicles (REEV), plug-in hybrid electric vehicles (PHEV), and new energy vehicles.

[0048] The above embodiments are merely preferred embodiments provided to fully illustrate the present utility model, and the protection scope of the present utility model is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present utility model are all within the protection scope of the present utility model.

Claims

1. A battery cell, comprising a battery cell unit (1) and an insulating layer (2), wherein the insulating layer (2) is disposed on the top surface of the battery cell unit (1), characterized in that: The isolation layer (2) has a through hole (21) in the area corresponding to the shoulder of the top surface of the battery cell (1), and the through hole (21) is filled with structural adhesive (4) for connection with the pressure strip (3); The top shoulder of the battery cell (1) and the pressure strip (3) are provided with a protrusion (6) and the other is provided with a groove (5) that matches the protrusion (6). The protrusion (6) extends into the groove (5) through the through hole (21).

2. The battery cell according to claim 1, characterized in that: The sidewall of the groove (5) or the side of the protrusion (6) is provided with a grid-like distribution of glue storage tanks (7).

3. The battery cell according to claim 1, characterized in that: The sidewall of the groove (5) or the side of the protrusion (6) is provided with protrusions (8) arranged in a grid pattern.

4. The battery cell according to claim 1, characterized in that: The orthographic projection of the through hole (21) on the top surface of the cell (1) covers the orthographic projection of the groove (5) on the top surface of the cell (1).

5. The battery cell according to claim 1, characterized in that: The top surface of the battery cell (1) is provided with a groove (5), and the bottom surface of the pressure strip (3) is provided with a protrusion (6) that fits the groove (5) with a gap.

6. The battery cell according to claim 1, characterized in that: The roughness of the groove wall of the groove (5) is greater than the preset roughness threshold.

7. The battery cell according to claim 1, characterized in that: The cross-sectional shape of the through hole (21) is rectangular, circular, triangular or waist-shaped.

8. The battery cell according to claim 1, characterized in that: The projected area of ​​the through hole (21) on the top surface of the battery cell (1) is greater than or equal to a preset area threshold.

9. A battery pack, characterized in that: Including the battery cell as described in any one of claims 1 to 8.

10. A vehicle, characterized in that: Includes the battery pack as described in claim 9.

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