Battery cover plate and battery

Abstract

The utility model relates to battery technical field provides a kind of battery cover plate and battery, comprising: light aluminum plate and lower plastic, first counterbore is opened to the side of light aluminum plate towards battery pole group, the opening end area of first counterbore is less than its bottom end area, it can be inverted conical structure;Lower plastic is provided with connecting column, connecting column is compatible with the opening end of first counterbore, and connecting column is connected with first counterbore by ultrasonic hot melting;The utility model connects light aluminum plate and lower plastic by ultrasonic hot melting, when connecting column is connected with first counterbore by ultrasonic hot melting, the connecting column material of fusion will be filled into the larger space of counterbore bottom end, after cooling solidification, this structure can form mechanical locking effect, compared with traditional only rely on riveting compression mode, effectively solve the problem that lower plastic is easily deformed warping and gap is generated with light aluminum plate at far away riveting position, significantly enhance the connection firmness of light aluminum plate and lower plastic.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery cover and a battery. Background Technology

[0002] As the performance requirements of lithium-ion batteries continue to increase in various application fields, battery safety, reliability and structural stability have become key issues. As an important part of the battery packaging structure, the performance of the battery cover directly affects the overall performance of the battery.

[0003] In the structure of lithium-ion batteries, the battery cover needs to seal and protect the internal electrode assembly while ensuring insulation between the electrode assembly and the casing. Currently, traditional battery cover panels primarily rely on the riveting and clamping of the electrode posts and riveting blocks to achieve connection. However, this connection method has significant technical drawbacks. In areas far from the riveting location, the lower plastic layer, lacking effective support and fixation, is prone to deformation and warping, leading to gaps between it and the aluminum plate and affecting the reliability of the connection between the aluminum plate and the lower plastic layer.

[0004] From the perspective of battery insulation performance, the edge of the lower plastic layer is usually connected to Mylar (polyester film) via heat fusion. This is to wrap the battery electrode assembly and insulate it from the casing. However, when the lower plastic layer warps, the Mylar wrapping the electrode assembly loosens, thereby compromising the insulation barrier between the electrode assembly and the casing, increasing the risk of short circuits, and seriously affecting product reliability and safety. Furthermore, during battery charging and discharging, the cell electrode assembly expands and exerts pressure on the cover plate. Traditional riveting and clamping joints cannot evenly distribute this pressure, making the lower plastic layer more prone to warping and deformation. Utility Model Content

[0005] This utility model provides a battery cover and a battery to solve the problem of poor connection reliability between the aluminum plate and the lower plastic in the battery cover in the prior art.

[0006] In a first aspect, this utility model provides a battery cover, comprising: A light aluminum plate, wherein a first countersunk hole is formed on the side of the light aluminum plate facing the battery cell electrode assembly, and the area of ​​the opening end of the first countersunk hole is smaller than the area of ​​its bottom end. The lower plastic part is provided with a connecting post, which is adapted to the opening end of the first countersunk hole, and the connecting post and the first countersunk hole are connected by ultrasonic heat fusion.

[0007] According to the battery cover provided by this utility model, it further includes: The second countersunk hole is located at the opening of the first countersunk hole and communicates with the first countersunk hole. The cross-sectional area of ​​the second countersunk hole along the first direction is greater than the opening end area of ​​the first countersunk hole. The first direction is the thickness direction of the aluminum plate. The second countersunk hole is used to receive the liquid material formed by the melting of the connecting column.

[0008] According to the present invention, the cross-sectional shape of the first countersunk hole is circular, and the cross-sectional shape of the second countersunk hole is circular.

[0009] According to the present invention, a battery cover plate is provided in which the first countersunk hole and the second countersunk hole are coaxially arranged.

[0010] According to the present invention, a battery cover plate is provided with a plurality of first countersunk holes, which are evenly distributed on the aluminum plate. The center distance L between two adjacent first countersunk holes along the second direction and along the third direction is between 10-120mm. The second direction is the length direction of the aluminum plate, and the third direction is the width direction of the aluminum plate.

[0011] According to the present invention, in a battery cover plate, the height h of the connecting post along the first direction is not greater than 6.3 mm.

[0012] According to the present invention, the bottom diameter D of the first countersunk hole is 0.3 mm larger than its opening diameter d, and the opening diameter d of the first countersunk hole is between 0.5 and 6 mm.

[0013] According to the present invention, the thickness t of the aluminum plate from the side facing away from the lower plastic to the bottom of the first countersunk hole is between 0.2 and 1.5 mm.

[0014] According to the present invention, in a battery cover plate, the depth G of the second countersunk hole is between 0.05-0.2 mm along the first direction, and the height h of the connecting post is at least 0.25 mm greater than the depth H of the first countersunk hole.

[0015] Secondly, this utility model also provides a battery, including a battery cover as described in the first aspect.

[0016] This utility model provides a battery cover plate, comprising an aluminum plate and a lower plastic layer. The aluminum plate has a first countersunk hole on the side facing the battery cell assembly. The opening area of ​​the first countersunk hole is smaller than its bottom area, and it can be an inverted conical structure. The lower plastic layer is provided with a connecting post, which is adapted to the opening end of the first countersunk hole, and the connecting post and the first countersunk hole are connected by ultrasonic heat fusion. This utility model connects the aluminum plate and the lower plastic layer by ultrasonic heat fusion. By setting the opening area of ​​the first countersunk hole in the aluminum plate to be smaller than its bottom area, a structure similar to an "inverted" connection is formed. When the connecting post and the first countersunk hole are connected by ultrasonic heat fusion, the molten connecting post material fills the bottom of the countersunk hole. Within a relatively large space, after cooling and solidification, this structure can form a mechanical locking effect. Compared with the traditional method of relying solely on riveting and pressing, it effectively solves the problem of easy deformation and warping of the lower plastic and gaps between it and the aluminum plate at locations far from the riveting position, significantly enhancing the connection between the aluminum plate and the lower plastic. The reliable connection between the lower plastic and the aluminum plate can prevent the Mylar film covering the electrode assembly from loosening due to warping of the lower plastic. Because the heat fusion connection between the connecting post and the first countersunk hole is tight and stable, the heat fusion wrapping state of the lower plastic edge and the Mylar film is maintained, thereby effectively ensuring the insulation effect between the electrode assembly and the shell, reducing the risk of battery short circuit, and improving product safety. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a cross-sectional view of the aluminum plate provided in this embodiment of the present invention.

[0019] Figure 2 This is an isometric view of the lower plastic provided in an embodiment of this utility model.

[0020] Figure 3 for Figure 1 A magnified view of a portion of the image.

[0021] Figure 4 This is an assembly diagram of the connecting column, the first countersunk hole, and the second countersunk hole provided in an embodiment of the present utility model.

[0022] Figure 5 This is a bottom view of the aluminum plate provided in this embodiment of the utility model.

[0023] Figure 6 This is a schematic diagram of the structure of the battery cover provided in an embodiment of the present invention.

[0024] Figure label: 1. Plain aluminum plate; 2. Lower plastic; 3. First countersunk hole; 4. Second countersunk hole; 5. Connecting post. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] The following is combined with Figures 1-6 This invention describes a battery cover and a battery.

[0027] like Figure 1 , Figure 2 and Figure 5 As shown, this utility model embodiment provides a battery cover plate, including: a light aluminum plate 1 and a lower plastic 2. The light aluminum plate 1 has a first countersunk hole 3 on the side facing the battery cell electrode assembly. The opening area of ​​the first countersunk hole 3 is smaller than its bottom area, and it can be an inverted conical structure. The lower plastic 2 is provided with a connecting post 5. The connecting post 5 is adapted to the opening end of the first countersunk hole 3, and the connecting post 5 and the first countersunk hole 3 are connected by ultrasonic heat fusion.

[0028] As can be seen from the above scheme, this utility model uses ultrasonic heat fusion to connect the aluminum plate 1 and the lower plastic 2. By setting the opening area of ​​the first countersunk hole 3 of the aluminum plate 1 to be smaller than the bottom area, a structure similar to an "inverted" structure is formed. When the connecting post 5 is connected to the first countersunk hole 3 by ultrasonic heat fusion, the molten material of the connecting post 5 will fill the larger space at the bottom of the countersunk hole. After cooling and solidification, this structure can form a mechanical locking effect. Compared with the traditional method of relying solely on riveting and pressing, this effectively solves the problem that the lower plastic 2 is prone to deformation and warping at locations far from the riveting position, resulting in gaps with the aluminum plate 1. This significantly enhances the connection strength between the aluminum plate 1 and the lower plastic 2. The reliable connection between the lower plastic 2 and the aluminum plate 1 can prevent the Mylar film covering the electrode assembly from loosening due to the warping of the lower plastic 2. Because the heat fusion connection between the connecting post 5 and the first countersunk hole 3 is tight and stable, the heat fusion wrapping state of the edge of the lower plastic 2 and the Mylar film is maintained, thereby effectively ensuring the insulation effect between the electrode assembly and the shell, reducing the risk of battery short circuit, and improving product safety.

[0029] It should be noted that during ultrasonic heat fusion connection, the ultrasonic welding equipment acts on the lower plastic 2 from the side close to the electrode group of the battery cell, causing the connecting post 5 to melt first on the side close to the aluminum plate 1. The melt forms an inverted structure and fills the first countersunk hole 3 of the aluminum plate 1.

[0030] Mylar film is a polyester film, scientifically known as polyethylene terephthalate (PET) film, which is widely used in insulation, packaging and electronic devices. In lithium-ion batteries, Mylar film is mainly used to wrap the negative electrode connector of the electrode assembly, which can prevent the negative electrode connector from directly contacting the battery casing, thereby preventing casing corrosion and leakage caused by overlapping and forming electronic pathways.

[0031] Reference Figure 3 Furthermore, it also includes a second countersunk hole 4, which is located at the opening of the first countersunk hole 3 and communicates with the first countersunk hole 3. The cross-sectional area of ​​the second countersunk hole 4 along the first direction is larger than the opening end area of ​​the first countersunk hole 3. The first direction is the thickness direction of the aluminum plate 1. The second countersunk hole 4 is used to receive the liquid material formed by the melting of the connecting column 5.

[0032] With this configuration, the second countersunk hole 4 is located at the opening of the first countersunk hole 3 and communicates with it. Its cross-sectional area is larger than that of the opening end of the first countersunk hole 3, which can form a buffer space when the connecting post 5 melts. When the ultrasonic heat melting melts the material of the connecting post 5, the excess liquid material will be guided into the second countersunk hole 4, preventing the molten material from overflowing to the outside of the connection surface between the aluminum plate 1 and the lower plastic 2, ensuring the flatness of the cover surface, and preventing assembly interference or Mylar film deformation caused by material accumulation. Furthermore, the mechanical locking is achieved through the inverted structure of the first countersunk hole 3, and the material receiving function of the second countersunk hole 4 prevents the material overflow during heat melting from interfering with the connection interface. The combination of the two can reduce local stress concentration caused by uneven material flow during heat melting, prevent the lower plastic 2 from warping due to uneven stress, and ensure that the cover maintains a zero-gap fit between the aluminum plate 1 and the lower plastic 2 during long-term use, improving the reliability of the battery packaging structure. This structure can reduce the manual cleaning of overflowing material after heat melting, improve industrial production efficiency, and reduce production costs.

[0033] In this embodiment, the first countersunk hole 3 has a circular cross-sectional shape and is an inverted conical structure. The second countersunk hole 4 has a circular cross-sectional shape and is a cylindrical structure. Preferably, the first countersunk hole 3 and the second countersunk hole 4 are coaxially arranged. Thus, the first countersunk hole 3 and the second countersunk hole 4 both have circular cross-sections and are coaxially arranged, allowing the countersunk hole structure to be efficiently realized during processing through rotary cutting or stamping. Compared to irregularly shaped holes, this significantly reduces processing difficulty. The fit tolerance between the circular countersunk hole and the cylindrical connecting post 5 is easier to control, ensuring the uniformity of material filling during hot melting and improving the consistency of mass production. The coaxial circular double countersunk hole structure can form a straight material flow channel. When the connecting post 5 melts, the liquid material can smoothly fill the inverted structure along the axial direction of the first countersunk hole 3, while excess material is guided into the second countersunk hole 4 along the axial direction. This avoids turbulence or bubbles caused by abrupt changes in cross-section during material flow, ensuring the density of the hot-melt connection interface and further enhancing the mechanical locking effect.

[0034] like Figure 5 As shown, the aluminum plate 1 has a rectangular structure and multiple first countersunk holes 3 are provided. The multiple first countersunk holes 3 are evenly distributed on the aluminum plate 1. The center distance L between two adjacent first countersunk holes 3 along the second direction and along the third direction is between 10-120mm. The second direction is the length direction of the aluminum plate 1, and the third direction is the width direction of the aluminum plate 1.

[0035] With this configuration, multiple first countersunk holes 3 are evenly distributed on the aluminum plate 1, which allows the connection force between the lower plastic 2 and the aluminum plate 1 to be evenly distributed across the entire cover plate surface. Compared to single-point or non-uniformly distributed connections, this configuration provides a more robust connection between the lower plastic 2 and the aluminum plate 1. The spacing L between adjacent first countersunk holes 3 is controlled between 10-120mm, which can be adjusted to accommodate different models of ultrasonic welding equipment. This avoids localized stress concentration due to excessively small spacing or weak connection areas due to excessively large spacing, ensuring that the force at each connection point is balanced when the cover plate is subjected to external pressure, vibration, or other conditions. This effectively suppresses the warping deformation of the lower plastic 2 and improves the overall connection reliability.

[0036] In some embodiments, the shape of the connecting post 5 is one of circular, square, elliptical, or polygonal, and the height h of the connecting post 5 along the first direction is not greater than 6.3 mm. When h > 6.3 mm, the top of the connecting post 5 is too far from the ultrasonic welding head, which may result in insufficient melting at the bottom and failure to fill the undercut structure of the first countersunk hole 3; when h ≤ 6.3 mm, the ultrasonic energy can be effectively transmitted to the bottom of the connecting post 5, ensuring that the molten material completely fills the countersunk hole.

[0037] like Figure 4 As shown, in this embodiment, the bottom diameter D of the first countersunk hole 3 is 0.3 mm larger than its opening diameter d, and the opening diameter d of the first countersunk hole 3 is between 0.5 and 6 mm.

[0038] With this configuration, the bottom diameter D of the first countersunk hole 3 is 0.3mm larger than the opening diameter d, forming an inverted cone-shaped interlocking structure that is smaller at the top and larger at the bottom. When the connecting column 5 is molten, the material fills the enlarged area at the bottom of the first countersunk hole 3. After cooling and solidification, it forms a mechanical locking structure. The inverted cone-shaped structure can guide the flow of the molten material of the connecting column 5, avoiding insufficient filling due to material accumulation.

[0039] like Figure 4As shown, in this embodiment, the thickness t of the aluminum plate 1 from the side facing away from the lower plastic 2 to the bottom of the first countersunk hole 3 is between 0.2 and 1.5 mm. This setting, controlling the thickness t of the aluminum plate 1 from the side facing away from the lower plastic 2 to the bottom of the first countersunk hole 3 within 0.2-1.5 mm, ensures that the remaining thickness of the aluminum plate 1 at the bottom of the first countersunk hole 3 has sufficient tear resistance and ensures the stability of the undercut structure of the first countersunk hole 3. When t < 0.2 mm, the aluminum plate 1 at the bottom of the countersunk hole is prone to cracking due to thermal stress; when t > 1.5 mm, ultrasonic energy is difficult to transmit to the bottom of the countersunk hole, resulting in insufficient melting of the connecting post 5.

[0040] like Figure 4 As shown, in some embodiments, along the first direction, the depth G of the second countersunk hole 4 is between 0.05 and 0.2 mm, and the height h of the connecting post 5 is at least 0.25 mm greater than the depth H of the first countersunk hole 3.

[0041] This design allows for the collection of excess liquid material from the melting of the connecting column 5. During ultrasonic heat melting, the depth of the second countersunk hole 4 can be adapted to different energy parameters. When the energy is too high and the material melts excessively, the second countersunk hole 4 can absorb the excess material without affecting the connection strength. It can also prevent material from overflowing to the outside of the connection interface between the aluminum plate 1 and the lower plastic 2, ensuring the flatness of the cover plate surface. When the energy is too low, the shallow groove structure will not form a depression due to insufficient material filling, ensuring the consistency of the cover plate surface. The difference between the height h of the connecting column 5 and the depth H of the first countersunk hole 3 ensures that there is enough material to fill the inverted structure of the first countersunk hole 3 after the connecting column 5 melts.

[0042] This utility model embodiment provides a battery, including the battery cover plate described above.

[0043] By using ultrasonic welding equipment to apply force to the lower plastic 2 from the side near the battery cell electrode assembly, the side of the connecting post 5 close to the aluminum plate 1 is melted. The molten liquid material of the connecting post 5 fills the inverted structure of the first countersunk hole 3 of the aluminum plate 1. After the material of the connecting post 5 cools and solidifies, it forms a mechanical lock with the inverted structure of the aluminum plate 1, thereby achieving a firm connection between the aluminum plate 1 and the lower plastic 2. The second countersunk hole 4 is used to accommodate excess material during the hot-melt process, preventing material overflow from affecting the connection effect and the flatness of the cover plate. Through the precise design of the structural parameters of each component, such as the center distance between adjacent double countersunk holes, the height of the connecting post 5, and the depth of the two countersunk holes, the flow and filling effect of the material during the hot-melt connection are ensured, guaranteeing the strength and tightness of the hot-melt connection, thereby achieving a reliable connection between the aluminum plate 1 and the lower plastic 2.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A battery cover, characterized in that, include: A light aluminum plate (1) has a first countersunk hole (3) on the side facing the battery cell electrode assembly. The area of ​​the opening end of the first countersunk hole (3) is smaller than the area of ​​its bottom end. The lower plastic (2) is provided with a connecting post (5), which is adapted to the opening end of the first countersunk hole (3) and the connecting post (5) is heat-fused to the first countersunk hole (3).

2. The battery cover according to claim 1, characterized in that, Also includes: The second countersunk hole (4) is located at the opening of the first countersunk hole (3) and communicates with the first countersunk hole (3). The cross-sectional area of ​​the second countersunk hole (4) along the first direction is greater than the opening end area of ​​the first countersunk hole (3). The first direction is the thickness direction of the light aluminum plate (1). The second countersunk hole (4) is used to receive the liquid material formed by the melting of the connecting column (5).

3. A battery cover according to claim 2, characterized in that, The first countersunk hole (3) has a circular cross-sectional shape, and the second countersunk hole (4) has a circular cross-sectional shape.

4. A battery cover according to claim 2, characterized in that, The first countersunk hole (3) and the second countersunk hole (4) are coaxially arranged.

5. A battery cover according to claim 4, characterized in that, Multiple first countersunk holes (3) are provided, and the multiple first countersunk holes (3) are evenly distributed on the aluminum plate (1). The center distance L between two adjacent first countersunk holes (3) along the second direction and along the third direction is between 10-120mm. The second direction is the length direction of the aluminum plate (1), and the third direction is the width direction of the aluminum plate (1).

6. A battery cover according to any one of claims 2-5, characterized in that, The height h of the connecting column (5) along the first direction is not greater than 6.3 mm.

7. A battery cover according to any one of claims 1-5, characterized in that, The bottom diameter D of the first countersunk hole (3) is 0.3 mm larger than its opening diameter d, and the opening diameter d of the first countersunk hole (3) is between 0.5 and 6 mm.

8. A battery cover according to any one of claims 1-5, characterized in that, The thickness t of the aluminum plate (1) from the side facing away from the lower plastic (2) to the bottom of the first countersunk hole (3) is between 0.2 and 1.5 mm.

9. A battery cover according to claim 6, characterized in that, Along the first direction, the depth G of the second countersunk hole (4) is between 0.05 and 0.2 mm, and the height h of the connecting post (5) is at least 0.25 mm greater than the depth H of the first countersunk hole (3).

10. A battery, characterized in that, Includes the battery cover as described in any one of claims 1-9.

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