Battery shell mold and aluminum-plastic film shell

Abstract

The utility model provides a kind of battery shell punching mould and aluminium plastic film shell, relate to battery technical field.A kind of battery shell punching mould, for the shell punching of aluminium plastic film in battery, it include: first template;Second template, second template is set on first template;Outer mould core, outer mould core is set in first template, outer mould core can slide in first template along vertical direction;Inner mould core, inner mould core is set in outer mould core, inner mould core can slide in outer mould core along vertical direction;When battery shell punching mould uses, aluminium plastic film is set between first template and second template, outer mould core and inner mould core are sequentially pressed to aluminium plastic film shell punching. By resolving total shell punching depth into outer mould core and inner mould core twice step-by-step stamping, each stamping depth is controlled in material safe tensile range, effectively alleviate the stress concentration phenomenon of corner region.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, specifically relating to a battery stamping mold and an aluminum-plastic film shell. Background Technology

[0002] Soft-pack lithium-ion batteries are widely used in new energy vehicles, energy storage systems, and consumer electronics due to their advantages such as high energy density, light weight, and customizable shape. In the manufacturing process of soft-pack batteries, aluminum-plastic film, as a key packaging material, needs to be formed into a cavity structure to house the battery cells through a stamping process. With the continuous increase in the capacity and volume of individual battery cells, the requirements for the stamping depth of the aluminum-plastic film are also increasing, especially for high-capacity soft-pack power batteries, whose stamping depth generally exceeds 6.5mm, and some products even reach over 8.5mm.

[0003] However, traditional single-stage stamping dies face significant technical bottlenecks when stamping deep cavity structures with a depth greater than 6.5mm. Due to the high stress concentration at the four corners of the aluminum-plastic film during stamping, the material undergoes severe tensile deformation, easily leading to excessive thinning or even cracking of the aluminum layer at the corners. Once the aluminum layer thickness falls below 60% of its original thickness, it cannot effectively isolate moisture and oxygen, severely weakening the protection of the internal chemical system of the battery cell, thus triggering safety risks such as battery swelling, leakage, internal short circuits, and even thermal runaway.

[0004] In existing technologies, to alleviate the above problems, methods such as increasing the stamping fillet radius, optimizing lubrication conditions, or selecting aluminum-plastic film materials with better ductility are commonly used. However, these methods have limited effectiveness when the stamping depth is further increased, and cannot fundamentally solve the problem of excessive thinning of the aluminum layer at the corners. In addition, some attempts have been made to achieve deep-stamped shells through multi-pass stamping processes, but these processes involve complex mold structures, poor positioning accuracy, low production efficiency, and difficulty in ensuring coordination between stamping passes, resulting in poor product consistency.

[0005] Therefore, there is an urgent need for a new type of stamping mold with a reasonable structure and controllable process, which can effectively control the deformation of the corner area of ​​the aluminum-plastic film while ensuring a high stamping depth, and ensure that the thickness of the aluminum layer at the corner after stamping is not less than 60% of the original thickness, thereby meeting the manufacturing requirements of high-safety soft-pack power batteries. Utility Model Content

[0006] The purpose of this invention is to address the aforementioned problems in the existing technology by proposing a battery casing die.

[0007] The objective of this utility model can be achieved through the following technical solution: a battery stamping mold for stamping aluminum-plastic film in batteries, comprising:

[0008] First template;

[0009] The second template is set on the first template;

[0010] An outer mold core is disposed in the first template and can slide vertically within the first template.

[0011] An inner mold core is disposed within the outer mold core, and the inner mold core can slide vertically within the outer mold core.

[0012] When the battery casing die is used, the aluminum-plastic film is placed between the first template and the second template, and the outer mold core and the inner mold core press down in sequence to punch the aluminum-plastic film.

[0013] As a further improvement of this utility model, the first template is provided with a stepped hole, the stepped hole including a first through hole and a second through hole connected together, the inner wall of the first through hole extends horizontally to the inner wall of the second through hole to form a stepped surface, when the outer mold core moves, the outer mold core is pressed into the first through hole until it abuts against the stepped surface, when the inner mold core moves, the inner mold core is pressed into the second through hole.

[0014] As a further improvement of this utility model, both the first through hole and the second through hole are set as rounded rectangles.

[0015] As a further improvement of this utility model, the length and width of the first through hole are both greater than those of the second through hole.

[0016] As a further improvement of this utility model, the length of the first through hole is greater than that of the second through hole, and the width of the first through hole is the same as that of the second through hole.

[0017] As a further improvement of this utility model, the inner mold core includes a mold core body and a stamping head that are detachably connected. The bottom of the mold core body is provided with a mounting groove, and the stamping head is at least partially disposed in the mounting groove.

[0018] As a further improvement of this utility model, the bottom surface of the inner mold core is set as a plane.

[0019] As a further improvement of this utility model, the punching depth of the inner mold core is greater than the punching depth of the outer mold core.

[0020] As a further improvement of this utility model, the sum of the punching depth of the inner mold core and the punching depth of the outer mold core is greater than 8.5mm.

[0021] This utility model also provides an aluminum-plastic film shell, which is punched using the above-mentioned battery punching mold. After the punching is completed, the thickness at the corner is greater than 60% of the initial thickness of the aluminum-plastic film.

[0022] Based on the above technical solution, this utility model can produce at least the following technical effects:

[0023] 1. By decomposing the total stamping depth into two step-by-step stamping processes, namely the outer die core and the inner die core, and controlling the stamping depth within the safe tensile range of the material each time, the stress concentration phenomenon in the corner area is effectively alleviated.

[0024] 2. The mold structure of this utility model is reasonably designed. The outer mold core and the inner mold core move sequentially in the stepped hole of the first template. With the step surface limiting, the positioning is accurate and the coordination is stable during the two stamping processes.

[0025] 3. By setting a detachable stamping head on the inner mold core, it is easy to quickly replace according to different product requirements or to maintain the stamping head after it wears out. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific 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.

[0027] Figure 1 This is a schematic diagram of the battery casing mold.

[0028] Figure 2 This is a cross-sectional view of a battery casing mold.

[0029] Figure 3 This is a top view of the first template in the battery casing mold.

[0030] Figure 4 This is a cross-sectional view of the first template in the battery casing mold.

[0031] Figure 5 This is a schematic diagram showing the completed aluminum-plastic film casing when the width of the second through hole in the battery casing mold is smaller than that of the first through hole.

[0032] Figure 6 This is a schematic diagram showing the completed aluminum-plastic film casing when the width of the second through hole in the battery casing mold is the same as that of the first through hole.

[0033] In the figure, 100 is the first template; 110 is the stepped hole; 111 is the first through hole; 112 is the second through hole; 113 is the stepped surface; 200 is the second template; 300 is the outer mold core; 400 is the inner mold core; 410 is the mold core body; 411 is the mounting groove; 420 is the stamping head; 500 is the aluminum-plastic film; and 510 is the corner position. Detailed Implementation

[0034] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this utility model are only used to explain the relative positional relationship and movement of the components in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indication will also change accordingly. Furthermore, in this utility model, descriptions involving "first," "second," "a," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly defined. In this utility model, unless otherwise explicitly specified and defined, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to the specific circumstances. Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope claimed by this utility model.

[0035] The following are specific embodiments of this utility model, in conjunction with the accompanying drawings. Figure 1-6 The technical solution of this utility model will be further described below, but this utility model is not limited to the following embodiments.

[0036] This utility model provides a battery stamping mold, mainly used for deep-drawing the aluminum-plastic film 500 in soft-pack lithium-ion batteries, especially suitable for high-capacity cell packaging scenarios with stamping depths greater than 6.5mm, or even exceeding 8.5mm. The mold consists of four main parts: a first template 100, a second template 200, an outer mold core 300, and an inner mold core 400. The first template 100 serves as the lower mold base, supporting and positioning the entire stamping structure; the second template 200 acts as the upper mold pressure plate, working in conjunction with the first template 100 to press the aluminum-plastic film 500; the outer mold core 300 is embedded inside the second template 200 and can slide vertically to complete the first stage of stamping; the inner mold core 400 is located inside the outer mold core 300 and also has vertical sliding capability, used for the second stage of stamping based on the first stage. This step-by-step stamping mechanism effectively disperses the deformation stress of the aluminum-plastic film 500 during deep drawing, particularly significantly alleviating the tensile concentration problem in the corner areas.

[0037] In terms of specific structure, the first template 100 has a stepped hole 110, which is composed of a first through hole 111 and a second through hole 112 that are connected vertically, and the two are connected by an annular stepped surface 113. The inner wall of the first through hole 111 extends horizontally to the inner wall of the second through hole 112 to form the stepped surface 113. The cross-sectional dimension of the first through hole 111 is larger than that of the second through hole 112. Both are preferably rounded rectangular structures to match the actual contour requirements of the soft-pack battery casing. The rounded corner design not only facilitates the material flow of the aluminum-plastic film 500 during the stamping process, but also effectively avoids the cracking of the aluminum layer caused by stress concentration at sharp corners. In a preferred embodiment, the length of the first through hole 111 is greater than that of the second through hole 112, while the width remains the same. In another preferred embodiment, both the length and width of the first through hole 111 are greater than those of the second through hole 112.

[0038] When the mold is working, the aluminum-plastic film 500 to be stamped is first placed flat on the upper surface of the first template 100, and then pressed down by the second template 200, so that the aluminum-plastic film 500 is stably clamped between the first template 100 and the second template 200, preventing it from slipping or wrinkling during subsequent stamping. Then, the outer mold core 300 moves downward under the action of a drive mechanism (such as a hydraulic cylinder or servo motor), passes through the corresponding opening of the second template 200, and enters the area of ​​the first through hole 111 to perform the first stage stamping of the aluminum-plastic film 500. At this time, the lower end face of the outer mold core 300 abuts against the stepped surface 113 in the stepped hole 110, forming a limit, ensuring that the first stage stamping depth is precisely controllable and within the safe stretching range of the material. During this process, the aluminum-plastic film 500 is initially stretched into a shallow cavity structure; although there is deformation in the corner area, it does not reach the critical rupture point.

[0039] Next, the inner mold core 400 begins to move. The inner mold core 400 continues to move downwards from inside the outer mold core 300, passes through the through-hole in the center of the outer mold core 300, and is further pressed into the second through-hole 112, completing the second stage of stamping. It is worth noting that while the inner mold core 400 is pressing down, the outer mold core 300 remains in contact with the stepped surface 113. This means that in the second stage of stamping, the outer mold core 300 and the stepped surface 113 of the first template 100 together form a new pre-tightening structure, continuously applying constraint force to the edge area of ​​the aluminum-plastic film 500, preventing excessive material flow towards the center during deep drawing and causing corner thinning. This "dynamic edge pressing" mechanism simulates the function of the edge pressing ring in a traditional multi-station stamping device, but is achieved through a structure integrated within the same mold, eliminating the need for additional equipment and significantly improving process integration and efficiency.

[0040] The structural design of the inner mold core 400 also fully considers practicality and maintainability. In a preferred embodiment, the inner mold core 400 is detachably connected from two parts: a mold core body 410 and a punch head 420. The bottom of the mold core body 410 has a mounting groove 411, into which the punch head 420 is at least partially embedded and fixed by screws, clips, or interference fits. This modular design allows the punch head 420 to be quickly replaced according to different product models, such as replacing punches with different depths, corner radii, or profiles, greatly improving the versatility and maintainability of the mold. The bottom surface of the inner mold core 400 is designed as a flat surface, which helps to flatten and compact the bottom of the shell during the stamping stage, avoiding bottom bulges or uneven thickness, further improving the integrity of the shell structure.

[0041] In this embodiment, the punching depth of the inner mold core 400 is greater than that of the outer mold core 300, and the sum of the punching depths of the inner mold core 400 and the outer mold core 300 is greater than 8.5mm, significantly exceeding the industry standard upper limit of 6.5mm. This utility model also provides an aluminum-plastic film shell. Using the aforementioned battery punching mold, after punching, the thickness at the corners 510 is greater than 60% of the initial thickness of the aluminum-plastic film 500. Actual testing shows that the aluminum-plastic film 500 punched using this utility model's battery punching mold has an aluminum layer thickness at all four corners 510 that fully meets the technical requirement of not less than 60%, and there are no visible cracks or pinhole defects. It should be noted that "corner 510" in this patent specifically refers to the four inner corner areas of the aluminum-plastic shell cavity after punching, which are the key areas where the aluminum layer is most prone to thinning or breakage.

[0042] This utility model mold also has significant advantages in manufacturing and assembly. All sliding mating surfaces (such as the outer mold core 300 and the first through hole 111, and the inner mold core 400 and the inner hole of the outer mold core 300) are precision machined and surface treated (such as chrome plating or nitriding) to reduce frictional resistance, improve wear resistance, and ensure smooth operation during long-term use. The first template 100 and the second template 200 can be made of high-strength alloy steel, possessing good rigidity and thermal stability, suitable for high-speed continuous stamping production lines. The entire mold has a compact and highly integrated structure, which can be directly installed on standard punch presses or hydraulic presses without requiring large-scale modifications to existing equipment, facilitating rapid promotion and application in battery manufacturing enterprises.

[0043] In summary, this invention, through its ingenious multi-layer core structure design, breaks down the highly complex deep-drawing shell process into multiple safe and controllable sub-steps. This not only effectively solves the technical challenge of excessive thinning of the aluminum layer at the 500mm corner of the aluminum-plastic film, but also takes into account production efficiency, product consistency, and equipment compatibility, providing key process support for the large-scale, high-reliability manufacturing of high-energy-density soft-pack lithium-ion batteries.

[0044] This utility model can also adjust the number of mold cores (such as expanding to three or more layers), stamping sequence, limiting structure or material parameters according to actual needs. These modifications should all be considered to fall within the protection scope of this utility model.

[0045] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A battery casing die for stamping aluminum-plastic film (500) in a battery, characterized in that, include: First template (100); The second template (200) is disposed on the first template (100); An outer mold core (300) is disposed in the second template (200) and the outer mold core (300) can slide vertically in the second template (200); An inner mold core (400) is disposed in the outer mold core (300), and the inner mold core (400) can slide vertically within the outer mold core (300); When the battery casing die is used, the aluminum-plastic film (500) is placed between the first template (100) and the second template (200), and the outer mold core (300) and the inner mold core (400) press down in sequence to punch the aluminum-plastic film (500).

2. The battery casing die according to claim 1, characterized in that, The first template (100) is provided with a stepped hole (110), the stepped hole (110) includes a first through hole (111) and a second through hole (112) connected together. The inner wall of the first through hole (111) extends horizontally to the inner wall of the second through hole (112) to form a stepped surface (113). When the outer mold core (300) moves, the outer mold core (300) is pressed into the first through hole (111) until it abuts against the stepped surface (113). When the inner mold core (400) moves, the inner mold core (400) is pressed into the second through hole (112).

3. A battery casing die according to claim 2, characterized in that, Both the first through hole (111) and the second through hole (112) are set as rounded rectangles.

4. A battery casing die according to claim 3, characterized in that, The length and width of the first through hole (111) are both greater than those of the second through hole (112).

5. A battery casing die according to claim 3, characterized in that, The length of the first through hole (111) is greater than the length of the second through hole (112), and the width of the first through hole (111) is the same as the width of the second through hole (112).

6. A battery casing die according to claim 2, characterized in that, The inner mold core (400) includes a mold core body (410) and a stamping head (420) that are detachably connected. The bottom of the mold core body (410) is provided with a mounting groove (411), and the stamping head (420) is at least partially disposed in the mounting groove (411).

7. A battery casing die according to claim 2, characterized in that, The bottom surface of the inner mold core (400) is set as a plane.

8. A battery casing die according to claim 1, characterized in that, The punching depth of the inner mold core (400) is greater than the punching depth of the outer mold core (300).

9. A battery casing die according to claim 1, characterized in that, The sum of the punching depth of the inner mold core (400) and the punching depth of the outer mold core (300) is greater than 8.5 mm.

10. An aluminum-plastic film casing, stamped using a battery stamping die as described in any one of claims 1-9, characterized in that, After the shell is punched, the thickness at the corner (510) is greater than 60% of the initial thickness of the aluminum-plastic film (500).

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