Battery top cover sealing structure and preparation process thereof

Abstract

The invention discloses a battery top cover sealing structure and a preparation process thereof, the sealing structure comprises a top cover plate body, a sealing ring and a pole, the top cover plate body is provided with a stepped pole hole, the periphery of the pole hole is provided with a crimping ring integrated with the top cover plate body, and the crimping ring is perpendicular to the top cover plate body and is not close to the edge of the pole hole. A supporting platform is formed between the crimping ring and the pole hole, the pole is arranged in the pole hole, one side, far away from the top cover plate body, of the pole is provided with an annular step, the sealing ring is arranged in a gap between the top cover plate body and the pole, one side, close to the pole, of the crimping ring is provided with an L-shaped crimping part, and the crimping part and the sealing ring are lower than the pole. The whole structure of the battery sealing cover is integrated, the crimping ring is directly adopted to fix the pole, the structural integrity is high, the sealing ring has sealing and insulating dual functions, the material consumption is low, laser electric welding and injection molding processes are omitted in the production process, the production takt is improved, the equipment investment is reduced, and the cost is effectively saved.

Description

Technical Field

[0001] The invention relates to a battery top cover sealing structure and a preparation process thereof, and relates to the field of lithium batteries. Background Art

[0002] Lithium batteries are widely used in consumer electronics, electric vehicles, energy storage systems and other fields due to their high battery density, long cycle life and fast charging capabilities. The poles of lithium batteries are generally fixed on their top covers, and then an insulating ring is injected on the outside of the poles to prevent short circuits at the poles. The following three schemes are generally used in the process of fixing the poles: Scheme 1, laser welding technology is used to weld the pole crimping ring to the aluminum plate of the top cover; Scheme 2, the inner pole is passed through the pole hole on the top cover, and then the outer pole is fixed by injecting plastic glue; Scheme 3, the inner pole is passed through the pole hole on the top cover, and then the pole crimping ring is welded to the aluminum plate of the top cover by laser welding technology. Among the above three methods, the laser welding method often results in poor pole sealing due to poor welding; the injection molding method often causes deformation or even falling off due to plastic aging and heat, which ultimately leads to a decrease in sealing effect. In the process of fixing the pole using these two solutions, two steps are involved: pole fixing and outer ring glue injection. Each link needs to be equipped with corresponding equipment and a lot of time. This situation leads to increased battery costs and reduced production efficiency. Therefore, it is necessary to design a more efficient and simple battery top cover sealing structure and its preparation process to reduce battery production costs and speed up battery production rhythm. Summary of the invention

[0003] The purpose of the present invention is to provide a battery top cover sealing structure and a preparation process thereof.

[0004] The technical solution for achieving the purpose of the present invention is: a battery top cover sealing structure, specifically including a top cover sheet body, a sealing ring, and a pole, the top cover sheet body is provided with a stepped pole hole, a crimping ring integral with the top cover sheet body is provided around the pole hole, the crimping ring is perpendicular to the top cover sheet body and is not close to the edge of the pole hole, a supporting platform is formed between the crimping ring and the pole hole, the pole is arranged in the pole hole, a side of the pole away from the top cover sheet body has an annular step, the sealing ring is arranged in the gap between the top cover sheet body and the pole, the side of the crimping ring close to the pole has an L-shaped crimping portion, and the crimping portion and the sealing ring are lower than the height of the pole.

[0005] The crimping ring and the top cover sheet body of the above-mentioned battery top cover sealing structure are an integrated structure. In the process of fixing the pole, it is only necessary to bend the crimping ring. After bending, the sealing ring can be embedded in the annular step to form an effective insulation area between the pole and the top cover sheet body. In the subsequent process of welding the bus and the pole, there is no need to use the plastic rubber ring on the outside of the top cover sheet to avoid short circuit problems.

[0006] The top cover sealing structure can effectively shorten the pole fixing process. No laser welding machine is required during the fixing process. On the one hand, it can save the cost of laser welding machine. On the other hand, since no welding is required, the production cycle is effectively improved, thereby effectively improving corporate profits.

[0007] On the other hand, the sealing ring in the above structure passes through the pole hole. Since the crimping ring and the top cover plate body adopt an integrated structure, there will be no laser welding or plastic sealing ring falling off. Compared with the original pole fixing structure, the sealing effect is better, there will be no battery leakage, and the battery safety is better.

[0008] Further or optionally, in order to optimize the insulation effect, a sealing ring is filled between the outer edge of the annular step of the pole and the crimping ring, and the sealing ring forms an annular insulation area outside the annular step of the pole, and the width of the annular insulation area is ≥1mm. With this solution, there is no need to subsequently coat the outer side of the pole with insulating glue, and the glue injection process can be further omitted, thereby improving the production cycle and saving the investment in glue injection equipment.

[0009] Further or optionally, in order to improve the weather resistance of the sealing ring in the working environment, the sealing ring material is fluororubber.

[0010] Further or optionally, in order to distinguish the positive and negative poles, improve the aesthetics of the battery, and further improve the insulation performance between the pole and the top cover sheet body, the outer layer of the crimping ring is also coated with PPS injection glue. In order to further facilitate the distinction between the positive and negative poles, the PPS injection glue can be in different colors. If different colors of PPS glue are not used to distinguish the positive and negative poles, the corresponding positions on the battery top cover can be marked to facilitate the distinction in subsequent production processes.

[0011] The present application also relates to a lithium battery top cover, which specifically includes a top cover sheet, an explosion-proof valve, a lower plastic and a liquid injection hole. The top cover sheet is provided with two poles, which adopt the above-mentioned sealing structure and are respectively connected to the positive and negative poles of the battery; the explosion-proof valve and the liquid injection hole are arranged between the two poles, and the lower plastic is installed under the top cover sheet.

[0012] The pole of a lithium battery top cover adopting the above structure is an integrated structure, and there is no risk of the crimping ring falling off, so it has better stability, lower probability of liquid leakage, and better overall battery safety. Compared with the traditional pole fixing method, it has lower production cost and more market competitive advantages.

[0013] Further or optionally, in order to facilitate quick disassembly and assembly of the lower plastic, the lower plastic is fixed to the top cover sheet by snapping or welding, and the specific fixing method is selected according to the structure of the lower plastic and the compatibility of the materials.

[0014] Further or optionally, the present application also relates to a forming process of a lithium battery top cover, which is used to prepare the above-mentioned top cover structure, and specifically adopts the following preparation steps:

[0015] S1: Take a metal sheet and perform a stamping process on the metal sheet according to specification requirements to obtain a prefabricated top cover sheet with punched holes;

[0016] S2: crimping the prefabricated top cover sheet and the crimping ring to form a top cover sheet body;

[0017] S3: Assemble the sealing ring and the pole to form a pre-installed top cover structure;

[0018] S4: pre-bending the crimping ring to make it tilt toward one side of the pole, thereby obtaining a pre-bent top cover structure;

[0019] S5: Cut the sealing ring so that its surface is flush with the crimping ring to obtain a pre-cut structure;

[0020] S6: further performing a bending process on the pre-cut structure to obtain the lithium battery top cover.

[0021] The above production process is simple and can save time and cost to a great extent compared with the traditional pole fixing method, and can greatly increase the production cycle and improve production efficiency.

[0022] Further or optionally, the above lithium battery top cover molding process also includes step S8: injecting glue into the crimping ring.

[0023] Further or optionally, the method for preparing the top cover sheet body in steps S1 and S2 is an integrated die-casting process or a powder metallurgy process.

[0024] By adopting the above technical solution, the present invention has the following beneficial effects:

[0025] (1) The battery sealing cover structure designed by the present invention is an integrated structure, and the pole is directly fixed by a crimping ring. The structure has a strong integrity, and the sealing ring has the dual functions of sealing and insulation. It uses less material, and eliminates laser welding and injection molding processes in the production process, thereby improving production rhythm, reducing equipment investment, and effectively saving costs.

[0026] (2) The present invention also limits the thickness of the insulating ring and the width of the pole insulation area, achieving a balance between process and cannibalization.

[0027] (3) The sealing ring of the present invention is made of fluororubber material, which has strong corrosion resistance in acid and alkali environments and a longer service life.

[0028] (4) The present invention also covers the battery cover pole area with PPS plastic, making the battery appearance more beautiful and easier to distinguish.

[0029] (5) The present invention also provides a lithium battery top cover, which adopts an integrated crimping ring. The strength of the pole part is greater than that of the traditional pole structure. The crimping ring is not easy to fall off. Compared with the traditional structure, it is less likely to have leakage problems and has a lower risk of use.

[0030] (6) The present invention also provides a lithium battery top cover molding process, which has simple steps and is easy to operate. It can effectively improve the production rhythm, save equipment investment, reduce production costs, and is conducive to improving the company's competitiveness.

[0031] (7) The bending process of the crimping ring of the present invention adopts a step-by-step reduction method, and the bending transition zone is provided with an arc chamfer, which can avoid the uneven thickness and breakage of the internal sealing ring caused by excessive impact, and further improve the overall safety of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments and in conjunction with the accompanying drawings, wherein

[0033] Figure 1 It is a structural schematic diagram of the present invention.

[0034] Figure 2 It is a schematic diagram of the present invention when the pole is not installed.

[0035] Figure 3 It is a schematic diagram of the lithium battery top cover structure of the present invention.

[0036] The reference numerals in the accompanying drawings are: top cover sheet body 1, pole hole 11, crimping ring 12, crimping portion (121), sealing ring 2, pole 3, top cover sheet 4, explosion-proof valve 5, lower plastic 6, injection hole 7. DETAILED DESCRIPTION

[0037] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0038] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0039] All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without creative work shall fall within the protection scope of the present invention.

[0040] (Example 1)

[0041] like Figure 1and Figure 2 A battery top cover sealing structure specifically includes a top cover sheet body 1, a sealing ring 2, and a pole 3. The top cover sheet body 1 is provided with a stepped pole hole 11, and a crimping ring 12 which is integral with the top cover sheet body 1 is provided around the pole hole. The crimping ring 12 is perpendicular to the top cover sheet body 1 and is not close to the edge of the pole hole 11. A supporting platform is formed between the crimping ring 12 and the pole hole 11. The pole 3 is arranged in the pole hole 11, and the side of the pole 3 away from the top cover sheet body 1 has an annular step. The sealing ring 2 is arranged in the gap between the top cover sheet body 1 and the pole 3, and the side of the crimping ring 12 close to the pole 3 has an L-shaped crimping portion 121, and the crimping portion 121 and the sealing ring 2 are lower than the pole height.

[0042] In the above structure, the top cover sheet body 1 and the crimping ring 12 are an integrated structure, which is prepared by an integral stamping or casting process.

[0043] The sealing ring 2 is filled between the outer edge of the annular step of the pole 3 and the crimping ring 12.

[0044] The sealing ring 2 forms an annular insulating area outside the annular step of the pole. In order to ensure the insulating effect of the sealing ring, its thickness needs to be strictly calculated to prevent it from short-circuiting and breaking down. The width of the annular insulating area is ≥1mm.

[0045] When the crimping ring 12 fixes the pole 3, a step-by-step closing method is adopted to prevent the sealing ring from being unevenly thick or broken due to excessive compression. The sealing ring 2 can also be provided with a margin near the annular step. The pressing head is heated during the pressing process to soften and deform the upper part of the sealing ring to fill the annular step.

[0046] In order to ensure insulation, the sealing ring 2 is made of fluororubber.

[0047] In order to further ensure the insulation effect and effectively distinguish the positive and negative poles, and make the battery look more beautiful, the outer layer of the crimping ring 12 is also coated with PPS injection molding glue.

[0048] like Figure 3 The present application also relates to a lithium battery top cover, including a top cover sheet 4, an explosion-proof valve 5, a lower plastic 6 and a liquid injection hole 7. The top cover sheet 4 is provided with two poles, and the poles adopt the sealing structure of claims 1 to 4 and are respectively connected to the positive and negative poles of the battery; the explosion-proof valve 5 and the liquid injection hole 7 are arranged between the two poles, and the lower plastic 6 is installed under the top cover sheet 4.

[0049] The lower plastic 6 is fixed to the top cover sheet 4 by means of snap-fit ​​or welding.

[0050] The present application also relates to a forming process for a lithium battery top cover, which adopts the following preparation steps:

[0051] S1: Take a metal sheet and perform a stamping process on the metal sheet according to specification requirements to obtain a prefabricated top cover sheet with punched holes;

[0052] S2: crimping the prefabricated top cover sheet and the crimping ring 12 to form a top cover sheet body;

[0053] S3: Assemble the sealing ring 2 and the pole 3 to form a pre-installed top cover structure;

[0054] S4: pre-bending the crimping ring 12 to make it tilt toward the pole 3 to obtain a pre-bent top cover structure;

[0055] S5: cutting the sealing ring so that its surface is flush with the crimping ring 12 to obtain a pre-cut structure;

[0056] S6: further performing a bending process on the pre-cut structure to obtain the lithium battery top cover.

[0057] The method further comprises step S8: injecting glue into the crimping ring 12 .

[0058] The preparation method of the top cover sheet body in steps S1 and S2 is an integrated die-casting process or a powder metallurgy process.

[0059] It should be understood that the present invention is described by some embodiments, and those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope of protection of the present invention.

Claims

1. A battery top cover sealing structure, characterized in that: The invention specifically comprises a top cover sheet body (1), a sealing ring (2), and a pole (3); the top cover sheet body (1) is provided with a stepped pole hole (11); a crimping ring (12) which is integral with the top cover sheet body (1) is provided around the pole hole; the crimping ring (12) is perpendicular to the top cover sheet body (1) and is not close to the edge of the pole hole (11); a supporting platform is formed between the crimping ring (12) and the pole hole (11); the pole (3) is arranged in the pole hole (11); a side of the pole (3) away from the top cover sheet body (1) has an annular step; the sealing ring (2) is arranged in the gap between the top cover sheet body (1) and the pole (3); a side of the crimping ring (12) close to the pole (3) has an L-shaped crimping portion (121); the crimping portion (121) and the sealing ring (2) are lower than the height of the pole.

2. A battery top cover sealing structure according to claim 1, characterized in that: A sealing ring (2) is filled between the outer edge of the annular step of the pole (3) and the crimping ring (12), and the sealing ring (2) forms an annular insulation area outside the annular step of the pole, and the width of the annular insulation area is ≥1 mm.

3. A battery top cover sealing structure according to claim 1 or 2, characterized in that: The sealing ring (2) is made of fluororubber.

4. A battery top cover sealing structure according to claim 1, characterized in that: The outer layer of the crimping ring (12) is also coated with PPS injection molding glue.

5. A lithium battery top cover, characterized in that: The invention comprises a top cover sheet (4), an explosion-proof valve (5), a lower plastic (6) and a liquid injection hole (7); the top cover sheet (4) is provided with two poles, the poles adopt the sealing structure in claims 1 to 4 and are respectively connected to the positive and negative poles of the battery; the explosion-proof valve (5) and the liquid injection hole (7) are arranged between the two poles, and the lower plastic (6) is installed below the top cover sheet (4).

6. A lithium battery top cover according to claim 5, characterized in that: The lower plastic (6) is fixed to the top cover sheet (4) by means of snap fastening or welding.

7. A forming process for a lithium battery top cover according to any one of claims 5 or 6, characterized in that The top cover sealing structure is prepared by the following steps: S1: Take a metal sheet and perform a stamping process on the metal sheet according to specification requirements to obtain a prefabricated top cover sheet with punched holes; S2: crimping the prefabricated top cover sheet and the crimping ring (12) to form a top cover sheet body; S3: Assemble the sealing ring (2) and the pole (3) to form a pre-installed top cover structure; S4: pre-bending the crimping ring (12) so that it is inclined toward one side of the pole (3) to obtain a pre-bent top cover structure; S5: cutting the sealing ring so that its surface is flush with the crimping ring (12) to obtain a pre-cut structure; S6: further performing a bending process on the pre-cut structure to obtain the lithium battery top cover.

8. The forming process of a lithium battery top cover according to claim 7, characterized in that: The method further comprises step S8: injecting glue into the crimping ring (12).

9. The forming process of a lithium battery top cover according to claim 7, characterized in that: The preparation method of the top cover sheet body in steps S1 and S2 is an integrated die-casting process or a powder metallurgy process.

Images