Lithium battery functional cover plate structure integrated with safety assembly

Abstract

The invention discloses a lithium battery functional cover plate structure integrated with a safety assembly, which comprises an integrally formed cover plate body, and the cover plate body is provided with a pressure response thinning area and a reinforcing rib area. The structure thickness of the pressure response thinning area is reduced relative to other areas of the cover plate body, and the pressure response thinning area deforms preferentially when the internal pressure of the lithium battery box body is abnormally increased, so that the internal pressure is converted into local displacement response of the cover plate; the reinforcing rib area is arranged around the pressure response thinning area and used for limiting the overall deformation path of the cover plate. By implementing a local thinning forming process on the pressure response thinning area, the pressure response thinning area and the cover plate body form a continuous transition structure, so that predictable and controllable structural response of the cover plate under the abnormal working condition is realized, the random failure risk is reduced, and the safety and reliability of a lithium battery system are improved.

Description

Technical Field

[0001] This invention relates to the field of lithium battery cover technology, and more specifically, to a functionalized lithium battery cover structure with integrated safety components. Background Technology

[0002] Lithium-ion batteries are widely used in new energy vehicles and energy storage systems due to their advantages such as high energy density and long cycle life. However, with the continuous increase in the capacity of power lithium-ion battery systems and the increasing integration of battery housings, the problems of heat and gas accumulation under abnormal operating conditions are becoming increasingly prominent. The structural safety of the battery housing has become one of the important factors restricting the safety of the entire vehicle.

[0003] In existing power lithium battery systems, the battery casing typically uses a metal shell and is sealed with a cover to protect the cells, modules, and internal electrical components. These covers are designed primarily for overall strength, sealing performance, and vibration and impact resistance, and their structures are often uniform thickness plates or simple reinforcing ribs. When the battery experiences abnormal conditions such as overcharging, internal short circuits, or thermal runaway, a large amount of gas is rapidly generated inside the casing, leading to a significant increase in internal pressure.

[0004] In existing technologies, to address abnormal internal pressure within the enclosure, pressure relief is typically achieved by installing explosion-proof valves, explosion-proof membranes, or grooved weak points on the enclosure or cover. However, these solutions often rely on passive structural breakage or opening. The timing and location of pressure relief are easily affected by manufacturing errors, material inhomogeneity, and installation conditions, leading to unpredictable pressure relief locations and unstable opening processes. In some cases, the cover may experience large-scale warping or unexpected breakage, potentially threatening surrounding structures or personnel safety.

[0005] Furthermore, existing explosion-proof structures often focus on a single weak point, lacking a systematic guidance for the overall stress and deformation path of the cover plate. During the process of internal pressure increase, the cover plate is often subjected to overall pressure, making local stress concentration difficult to control and prone to random failure. At the same time, some pressure relief structures require additional independent components or complex mechanisms in their design, which not only increases manufacturing and assembly costs but also hinders their integration into existing power battery box production lines.

[0006] Therefore, how to enable the cover plate of the power lithium battery box to generate a controllable response in a preset area under abnormal operating conditions without significantly increasing structural complexity and manufacturing costs, and guide the overall deformation behavior of the cover plate to reduce the risk of random damage and improve the safety and reliability of the battery system has become a technical problem that urgently needs to be solved in this field.

[0007] Based on these shortcomings, there is an urgent need for a functional cover structure for lithium batteries that integrates safety components to solve these problems. Summary of the Invention

[0008] The purpose of this invention is to solve the technical problems mentioned in the background art above, and to provide a functional cover structure for lithium batteries with integrated safety components. The cover structure is characterized by including an integrally formed cover body, which is used to close the opening of the lithium battery box, and has at least one pressure response thinning area thereon, which has a reduced structural thickness relative to other areas of the cover body. The cover plate body is also provided with several reinforcing rib areas, which are arranged around the pressure response thinning area (2) to limit the overall deformation path of the cover plate body when the internal pressure of the lithium battery is abnormal.

[0009] As a preferred embodiment of the present invention, the pressure-response thinning region is configured to preferentially deform when the internal pressure of the lithium battery housing increases, thereby converting the internal pressure into a local displacement response of the cover plate body. As a preferred technical solution of the present invention, the pressure response thinning region is a thin-walled structure with local depressions or local protrusions, and its outline shape is circular, elliptical or polygonal.

[0010] As a preferred technical solution of the present invention, the reinforcing rib area has a strip-shaped, grid-shaped, or frame-shaped structure, and is arranged alternately along the length and width directions of the cover plate body.

[0011] As a preferred technical solution of the present invention, a stiffness difference is formed between the reinforcing rib area and the pressure response thinning area, so that the pressure response thinning area deforms before the reinforcing rib area under the action of internal pressure.

[0012] As a preferred technical solution of the present invention, the edge area of ​​the cover plate body is provided with a plurality of mounting holes for fixing and sealing the cover plate body and the lithium battery box.

[0013] As a preferred technical solution of the present invention, the cover plate body is made of aluminum alloy or steel alloy material.

[0014] As a preferred technical solution of the present invention, the pressure response thinning zone is formed by a local thinning forming process on a preset area of ​​the cover plate body.

[0015] This invention also proposes a process for treating the pressure-response thinning region on a lithium battery cover, comprising the following steps: S1: Area Determination Steps: Based on the structural dimensions and stress characteristics of the cover plate body, determine the location and contour range of the pressure response thinning zone on the cover plate body; S2: Local thinning forming step: Local thinning forming process is performed on the preset area corresponding to the pressure response thinning area so that the structural thickness of the area is less than that of the rest of the cover plate body; S3: Transition shaping step: Perform transition shaping on the adjacent area between the pressure response thinning zone and the cover plate body to form a continuous transition structure at the edge of the thinning zone; S4: Inspection and Confirmation Steps: The thickness and morphology of the formed pressure response thinning zone are inspected to confirm that it meets the preset pressure response requirements.

[0016] As a preferred technical solution of the present invention, the local thinning forming process adopts at least one of local rolling, local embossing, deep drawing, laser removal or chemical etching.

[0017] Compared with the prior art, the present invention has the following beneficial effects: Compared with the prior art, the present invention has at least the following beneficial effects: Compared with the prior art, the lithium battery cover plate with integrated safety response structure provided by the present invention has at least the following beneficial effects: First, this invention creates a pressure-response thinning zone on the cover plate body, forming a clear stiffness difference with the reinforcing rib zone. This allows the cover plate to preferentially generate a structural response at a preset location when the internal pressure of the lithium battery abnormally increases, thereby avoiding random deformation or unexpected breakage of the cover plate as a whole. This structural guidance method enables predictable control over the deformation location and path of the cover plate, improving the safety and reliability of the battery housing under abnormal operating conditions.

[0018] Secondly, the pressure-response thinning zone in this invention is not a simple weak point, but a controllable deformation structure formed through a local thinning process. It can undergo elastic or plastic deformation in the early stages of internal pressure increase, thereby converting the internal pressure of the housing into a local displacement response of the cover plate. This "deformation-first" design eliminates the reliance on sudden rupture for safety response, providing early triggering conditions for subsequent safety linkages or pressure relief structures, and reducing the risks associated with rapid pressure release during thermal runaway.

[0019] Furthermore, by arranging reinforcing ribs on the cover plate body and coordinating its forming process with the thinning zone forming process, the cover plate maintains overall structural strength and installation rigidity while possessing locally sensitive and overall controlled and stable mechanical characteristics. This structure can meet the vibration, impact, and sealing requirements of the power battery box under normal driving conditions, and effectively suppress large-area warping or structural failure under abnormal conditions, thereby improving the overall service reliability of the cover plate.

[0020] Furthermore, this invention directly integrates the pressure response function into the cover plate structure, eliminating the need for additional independent pressure-sensing elements or complex mechanical mechanisms. This results in a simple structure with fewer parts, reducing manufacturing costs and assembly complexity. Simultaneously, the pressure response thinning zone can be achieved through various mature local thinning forming processes, offering flexible and adaptable options. This allows for direct implementation on existing power battery box cover plate production lines, demonstrating good engineering feasibility and industrial application value.

[0021] Finally, by systematically designing and controlling the processing technology of the pressure response thinning zone, a continuous transition structure is formed between the thinning zone and the cover plate body. This effectively reduces the risk of stress concentration and fatigue damage, improves the structural stability of the cover plate under long-term pressure fluctuations and vibration environments, thereby extending the overall service life of the lithium battery box and improving the safety level of the vehicle's power battery system. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a process flow diagram of the pressure response thinning zone of the present invention.

[0023] The components include: 1. Cover plate body; 2. Pressure response thinning zone; 3. Reinforcing rib zone; 4. Mounting holes. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the following description is provided in conjunction with embodiments and appendices. Figure 1 and Figure 2 The present invention will be further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0025] The following detailed description, in conjunction with specific embodiments of the present invention, illustrates a functionalized cover structure for a lithium battery integrating safety components. It should be understood that the following embodiments are merely illustrative of the technical concept of the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0026] Example 1: As shown in the accompanying drawings, the present invention provides a functional cover structure for lithium batteries with integrated safety components, including a cover body 1. The cover body 1 is an integrally formed plate structure used to seal the opening of the lithium battery housing, preferably applied to the power battery housing of new energy vehicles. While meeting the requirements of housing sealing, structural strength, and installation reliability, the cover body 1 achieves passive response and safety protection against abnormal internal pressure of the battery through local structural design.

[0027] In this embodiment, the cover plate body 1 is made of aluminum alloy or steel alloy, and its overall thickness is designed according to the box size and strength requirements. To achieve the pressure response function, at least one pressure response thinning zone 2 is provided at a preset position on the cover plate body 1. The pressure response thinning zone 2 has a reduced structural thickness relative to other areas of the cover plate body 1, thereby having lower bending stiffness and higher deformation sensitivity under the same stress conditions. The thinning zone 2 can be set as a thin-walled structure with local concavity or local convexity, and its outline shape can be circular, elliptical, or polygonal. The specific shape is designed to match the gas distribution characteristics and pressure concentration areas inside the box.

[0028] To ensure the overall structural stability of the cover plate under normal operating conditions and limit the deformation range under abnormal operating conditions, several reinforcing rib zones 3 are also provided on the cover plate body 1. These reinforcing rib zones 3 can be strip-shaped, grid-shaped, or frame-shaped, and are arranged alternately along the length and width directions of the cover plate body 1 to form a structural support network covering the entire cover plate area. Through the rational layout between the reinforcing rib zones 3 and the pressure response thinning zone 2, a significant difference in structural stiffness is created between the two. Therefore, when the internal pressure of the lithium battery box increases, the pressure response thinning zone 2 can deform preferentially, while the reinforcing rib zones 3 remain relatively stable, thus limiting the overall warping and unintended deformation paths of the cover plate body 1.

[0029] Under normal operating conditions, the internal pressure of the lithium battery casing remains within a safe range, the cover plate body 1 remains flat, and the pressure response thinning zone 2 does not undergo significant deformation, thus not affecting the sealing and structural performance of the casing. When the internal pressure of the casing gradually increases due to abnormal conditions such as overcharging, internal short circuit, or thermal runaway, the internal pressure acts on the inner surface of the cover plate body 1. Due to the low local stiffness of the pressure response thinning zone 2, this area first undergoes elastic or plastic deformation, thereby converting the internal gas pressure into a local displacement response of the cover plate body 1. In this way, an early response to abnormal internal pressure can be achieved before the entire cover plate is damaged, providing reliable triggering conditions for subsequent safety linkage or pressure relief structures.

[0030] Several mounting holes 4 are provided on the edge area of ​​the cover plate body 1. The mounting holes 4 are used to achieve a fixed connection between the cover plate body 1 and the lithium battery box. The mounting holes 4 can be used with bolts, riveting or welding, and combined with sealing gaskets or sealing adhesive layers to achieve an airtight connection between the cover plate and the box, preventing external environmental media from entering the box, and ensuring that the cover plate will not fall off completely during pressure response.

[0031] In this embodiment, the pressure response thinning zone 2 is formed through a local thinning forming process. Specifically, after the cover plate body 1 is formed, the setting position and contour range of the pressure response thinning zone 2 are determined according to the design requirements, and the edge of the cover plate body 1 or the mounting hole 4 is used as the positioning reference for clamping. Subsequently, a local thinning forming process is performed on the preset area so that the structural thickness of this area is less than that of the rest of the cover plate body 1, thereby forming the expected stiffness difference.

[0032] The localized thinning forming process can employ at least one of the following methods: localized rolling, localized embossing, deep drawing, laser removal, or chemical etching. Specifically, localized rolling or embossing processes apply controlled pressure to a localized area of ​​the cover plate, causing the material to flow plastically and form a thin-walled structure; deep drawing processes can achieve the desired thinned profile in one or more steps under the action of a die; and laser removal or chemical etching processes achieve finer thickness control through material removal, making them suitable for applications with high response threshold requirements.

[0033] After completing the local thinning process, the adjacent areas of the pressure response thinning zone 2 and the cover plate body 1 can be subjected to transition shaping to create a continuous and smooth transition structure at the edge of the thinning zone, thereby reducing the risk of stress concentration and fatigue cracking. Finally, the quality of the formed pressure response thinning zone 2 is verified through thickness and morphology inspection to ensure that it meets the design requirements for pressure response characteristics.

[0034] Through the above structural design and process, the lithium battery cover in this embodiment maintains the overall structural strength and sealing performance while generating a predictable and controllable structural response under abnormal operating conditions of the lithium battery, thereby reducing the overall failure risk of the cover and improving the safety and reliability of the lithium battery system. Example

[0035] In another embodiment, the formation of the pressure response thinning zone 2 adopts a pre-forming combined with secondary finishing process to improve the deformation consistency and fatigue reliability of the thinning zone, which is suitable for lithium battery case cover plates with high requirements for pressure response stability.

[0036] Specifically, the cover plate body 1 is first integrally stamped or molded to obtain the basic shape and structural form of the reinforcing rib area 3 required by the design. In this stage, the position corresponding to the pressure response thinning area 2 is reserved as a transition area with uniform thickness, instead of directly forming the final thinning thickness, so as to avoid uneven material flow or local stress concentration during the one-time forming process.

[0037] Subsequently, in the secondary forming process, the pressure-responsive thinning zone 2 undergoes a finishing thinning process. This finishing thinning process applies localized controlled pressure to the corresponding position of the thinning zone using a special mold, causing directional plastic deformation of the material in that area, thereby forming a predetermined thin-walled structure in the thinning zone 2. By controlling the stroke, contact area, and force distribution of the finishing mold, the thickness of the pressure-responsive thinning zone 2 is gradually reduced to the design requirements, while ensuring the continuity of the thinning zone's contour boundary.

[0038] After the finishing and thinning are completed, a transition trimming process is performed on the area adjacent to the pressure response thinning zone 2 and the cover plate body 1 to form a smooth transition structure at the edge of the thinning zone, thereby reducing the risk of fatigue cracks caused by repeated pressure fluctuations during subsequent use. The transition trimming process can be completed by mold shaping, rolling trimming, or local polishing.

[0039] Finally, the formed pressure-response thinning zone 2 undergoes quality inspection, including testing the thickness distribution, contour dimensions, and surface condition of the thinning zone, to confirm that the thinning zone 2 has consistent structural characteristics at different locations. The cover plate body 1, after passing the inspection, can proceed to subsequent assembly or surface treatment processes.

[0040] The pressure-response thinning zone 2 formed by the above processing technology, compared with the single-stage thinning method, can improve its structural stability under long-term vibration and periodic pressure while ensuring the response sensitivity of the thinning zone. This allows the cover plate to exhibit more predictable and repeatable pressure response behavior under abnormal lithium battery operating conditions.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A functionalized cover structure for a lithium battery with integrated safety components, characterized in that, Includes an integrally formed cover body (1), the cover body (1) is used to close the opening of the lithium battery box, and has at least one pressure response thinning area (2) thereon, the pressure response thinning area (2) having a reduced structural thickness relative to other areas of the cover body (1); The cover plate body (1) is also provided with several reinforcing rib areas (3), which are arranged around the pressure response thinning area (2) to limit the overall deformation path of the cover plate body (1) when the internal pressure of the lithium battery is abnormal.

2. The lithium battery functionalized cover structure with integrated safety components according to claim 1, characterized in that, The pressure-response thinning region (2) is configured to preferentially deform when the internal pressure of the lithium battery housing increases, thereby converting the internal pressure into a local displacement response of the cover plate body (1). According to claim 1 or 2, the lithium battery functionalized cover structure with integrated safety components is characterized in that the pressure response thinning area (2) is a thin-walled structure with local depressions or local protrusions, and its outline shape is circular, elliptical or polygonal.

3. The lithium battery functionalized cover structure with integrated safety components according to claim 1, characterized in that, The reinforcing rib area (3) has a strip-shaped, grid-shaped or frame-shaped structure, and is arranged alternately along the length and width directions of the cover plate body (1).

4. The lithium battery functionalized cover structure with integrated safety components according to claim 4, characterized in that, A stiffness difference is formed between the reinforcing rib area (3) and the pressure response thinning area (2), causing the pressure response thinning area (2) to deform before the reinforcing rib area (3) under internal pressure.

5. The lithium battery functionalized cover structure with integrated safety components according to claim 1, characterized in that, The edge area of ​​the cover plate body (1) is provided with several mounting holes (4) for fixing and sealing the cover plate body (1) and the lithium battery box.

6. A functionalized cover structure for a lithium battery with integrated safety components according to any one of claims 1-6, characterized in that, The cover plate body (1) is made of aluminum alloy or steel alloy material.

7. A lithium battery functionalized cover structure with integrated safety components according to any one of claims 1-7, characterized in that, The pressure response thinning zone (2) is formed by a local thinning forming process on a preset area of ​​the cover plate body (1).

8. A processing method for forming a pressure-responsive thinning region on a lithium battery cover plate according to any one of claims 1-8, characterized in that, Includes the following steps: S1: Area determination steps: Based on the structural dimensions and stress characteristics of the cover plate body (1), determine the setting position and contour range of the pressure response thinning zone (2) on the cover plate body (1); S2: Local thinning forming step: Local thinning forming process is performed on the preset area corresponding to the pressure response thinning area (2) so that the structural thickness of the area is less than the rest of the cover plate body (1); S3: Transition shaping step: Transition shaping treatment is performed on the adjacent areas of the pressure response thinning zone (2) and the cover plate body (1) to form a continuous transition structure at the edge of the thinning zone; S4: Inspection and confirmation steps: The thickness and morphology of the formed pressure response thinning zone (2) are inspected to confirm that it meets the preset pressure response requirements.

9. The processing method for the pressure-response thinning zone according to claim 9, characterized in that, The local thinning forming process employs at least one of the following: local rolling, local embossing, deep drawing, laser removal, or chemical etching.

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