Explosion-proof valve patch and cell housing

Abstract

The utility model relates to power battery technical field relates to explosion -proof valve patch and electric core casing, aiming at explosion -proof valve patch of prior art, in the electric core process because of the insufficient sticking strength easy to fall off or deformation, and lack pressure regulation mechanism, lead to explosion -proof valve protection failure, cause electric core safety technical problem, the utility model provides explosion -proof valve patch, including base body and the glue layer that applies to the peripheral annular area of base body, the gas -permeable groove that is penetrated along its thickness direction is set up in base body, the periphery of base body still is equipped with the cladding area, the periphery of base body is around setting up, and the periphery of base body adopts the way of partial cladding or overall cladding to cladding with cladding area, the back of cladding area can be optionally applied or not applied the same glue layer with the peripheral annular area of base body, reduced because of the risk of differential pressure and other factors and lead to explosion -proof valve patch fall off, deformation protection function failure, further, the utility model still provides a kind of electric core casing.

Description

Technical Field

[0001] This utility model relates to the field of power battery technology, specifically to an explosion-proof valve patch and a cell housing. Background Technology

[0002] With the rapid development of new energy technologies, power batteries have been widely used in electric vehicles, energy storage systems, and other fields. The safety of power batteries has always been a key focus of the industry. Among these, the explosion-proof valve, a crucial safety component of lithium batteries, is typically located on the cover or casing. When the internal pressure of the battery exceeds the safe pressure, the explosion-proof valve opens promptly to release the high-pressure gas, effectively preventing further pressure increases, preventing battery runaway, and reducing the risk level.

[0003] However, in practical applications, there are some problems with the protection of explosion-proof valves. To protect explosion-proof valves from damage and contamination, a protective film is usually attached to the outside of the valve. A sealed space is formed between the explosion-proof valve, the substrate, and the explosion-proof valve patch. During the cell manufacturing process, alternating positive and negative pressure environments often occur. If the sealed space cannot effectively and promptly regulate the pressure difference, abnormalities such as dents, warping, and detachment of the explosion-proof valve patch may occur. Once the explosion-proof valve patch fails, the explosion-proof valve will lose its protection, which may subsequently lead to corrosion and damage to the valve surface, resulting in a series of safety and appearance problems in the cell.

[0004] Existing explosion-proof valve patch designs have several shortcomings. Traditional explosion-proof valve patches have a relatively simple structure, consisting only of an adhesive layer attached to the outside of the explosion-proof valve. For example, Chinese Utility Model Authorization Announcement No. CN220456585U, filed on July 31, 2023, entitled "Explosion-proof Valve Protective Film and its Cell Housing and Battery," discloses an explosion-proof valve protective film comprising a substrate and an adhesive layer around the substrate; a slit extending through the substrate along its thickness direction on one side of the substrate; an adhesive layer extending from the periphery of the substrate to the slit and covering the slit; and a venting structure on the adhesive layer, connected to the slit. This protective film has limited adhesive strength and is unable to effectively cope with the complex pressure changes during cell manufacturing. Under alternating positive and negative pressure, the patch is prone to detachment or deformation due to pressure differences, leading to protection failure. Furthermore, traditional patch designs lack an effective mechanism for pressure regulation within confined spaces, failing to simultaneously address the protection of the explosion-proof valve and the regulation of internal ventilation.

[0005] Therefore, in the battery cell manufacturing process, how to improve the bonding strength of the explosion-proof valve patch and effectively regulate the pressure difference in the confined space to prevent the patch from falling off or deforming and to ensure the reliable protection of the explosion-proof valve is an urgent problem to be solved. Summary of the Invention

[0006] 1. The problem to be solved

[0007] In view of the existing explosion-proof valve patch, it is easy to fall off and deform during the battery cell manufacturing process due to insufficient bonding strength, and the lack of pressure regulation mechanism leads to the failure of explosion-proof valve protection, causing technical problems of battery cell safety and appearance. This utility model provides an explosion-proof valve patch, which reduces the risk of explosion-proof valve patch falling off or deforming and failing protection function due to pressure difference or other factors. Furthermore, this utility model also provides a battery cell housing.

[0008] 2. Technical Solution

[0009] To solve the above problems, the technical solution provided by this utility model is as follows:

[0010] The first aspect of this utility model provides an explosion-proof valve patch, including a substrate and an adhesive layer applied to an annular area around the substrate; the substrate has a permeable groove extending through its thickness direction, and a covering area is also provided around the periphery of the substrate, the covering area is arranged around the periphery of the substrate, and the covering area partially or fully covers the periphery of the substrate; the back of the covering area may be selectively coated with or not coated with the same adhesive layer as the annular area around the substrate.

[0011] According to any embodiment of the first aspect of this utility model, the thickness of the covered area of ​​the explosion-proof valve patch is equal to the thickness of the substrate.

[0012] By setting the thickness of the covering area to be equal to the thickness of the substrate, the uniformity and stability of the overall structure of the patch can be ensured, and stress concentration problems caused by thickness differences can be avoided, thereby further improving the bonding strength and reliability of the patch.

[0013] According to any embodiment of the first aspect of this utility model, the height of the covered area of ​​the explosion-proof valve patch is 0.2mm to 2mm. Preferably, the height of the covered area is 0.7mm.

[0014] The height of the covering area is limited to 0.2mm to 2mm, preferably 0.7mm. This ensures sufficient covering strength while avoiding the impact on the overall assembly and space utilization efficiency of the cell housing due to excessively high covering area, thus ensuring the compatibility between the patch and the cell housing.

[0015] According to any embodiment of the first aspect of this utility model, the thickness of the covered area of ​​the explosion-proof valve patch is 0.05 to 5.0 mm.

[0016] Setting the thickness of the coating area within the range of 0.05 to 5.0 mm provides more flexible design options, which can be adjusted according to different application scenarios and patch sizes, thereby better meeting the design requirements of various cell housings and improving the versatility and adaptability of the patch.

[0017] According to any embodiment of the first aspect of this utility model, the thickness of the substrate of the explosion-proof valve patch is 0.15mm to 0.25mm; the thickness of the adhesive layer is 0.05mm to 0.2mm. Preferably, the thickness of the substrate is 0.2mm; the thickness of the adhesive layer is 0.1mm.

[0018] By limiting the substrate thickness to 0.15mm to 0.25mm and the adhesive layer thickness to 0.05mm to 0.2mm, with a preferred substrate thickness of 0.2mm and an adhesive layer thickness of 0.1mm, the material usage can be optimized and production costs reduced while ensuring patch strength and breathability, and the reliability and durability of the patch under complex working conditions can be guaranteed.

[0019] According to any embodiment of the first aspect of this utility model, the explosion-proof valve patch can be provided with 1 to 9 venting grooves according to the venting level requirements, and the grooves can be designed to be independent or connected to each other; the positional relationship of the venting grooves is centrally symmetrical; the size of the venting grooves is 0.1mm to 5mm.

[0020] The design allows for 1 to 9 ventilation slots, depending on the required ventilation level. These slots can be independent or interconnected, with their positions being centrally symmetrical and their dimensions ranging from 0.1mm to 5mm. This design enables flexible adjustment of ventilation performance based on the internal pressure regulation needs of the battery cell, ensuring effective balance of pressure differences within the confined space under different operating conditions and further enhancing the protective effect of the explosion-proof valve.

[0021] According to any embodiment of the first aspect of this utility model, the explosion-proof valve patch has a mesh-like adhesive layer.

[0022] Designing the adhesive layer as a grid effectively improves its breathability and bonding strength, while reducing the risk of clogging the air channels. This ensures that the patch maintains good breathability and bonding stability during long-term use, further enhancing the functionality and reliability of the explosion-proof valve protective film.

[0023] According to any embodiment of the first aspect of this utility model, the explosion-proof valve patch has a substrate and / or covering area made of PET, PP, PE or PI; and an adhesive layer made of 3M467 or DSTT-10M.

[0024] PET, PP, PE or PI are selected as the matrix and / or coating material, and 3M467 or DSTT-10M are selected as the adhesive layer material. These materials have good mechanical properties, chemical resistance and adhesion, which can ensure the long-term stability of the patch under complex working conditions, while meeting the material performance requirements of different application scenarios, and further improving the practicality and reliability of the patch.

[0025] According to any embodiment of the first aspect of the present invention, the explosion-proof valve patch has a release paper on the side of the adhesive layer away from the substrate.

[0026] Placing release paper on the side of the adhesive layer away from the substrate effectively prevents the adhesive layer from sticking or becoming contaminated during production, transportation, and storage. This ensures that the patch can be quickly and accurately attached to the explosion-proof valve during use, improving production efficiency and product quality, while also extending the shelf life of the patch.

[0027] The second aspect of this utility model provides a battery cell housing, including the aforementioned explosion-proof valve patch.

[0028] 3. Beneficial effects

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] (1) The explosion-proof valve patch of this utility model significantly enhances the adhesive strength of the patch by setting a covering area around the substrate, effectively reducing problems such as patch detachment and deformation caused by pressure difference or other factors, thereby ensuring reliable protection of the explosion-proof valve. At the same time, the design of the venting groove can adjust the pressure difference in the sealed space, taking into account both the protection of the explosion-proof valve and the adjustment function of the internal space's ventilation capacity. Moreover, the covering area can be flexibly adjusted according to the size of the patch, further improving the adaptability and practicality of the design.

[0031] (2) The cell housing of this utility model can effectively improve the protection performance of the explosion-proof valve and avoid corrosion or damage to the explosion-proof valve due to patch failure, thereby ensuring the safety and stability of the cell under complex working conditions. In addition, the flexible design of the patch can also adapt to cell housings of different specifications, further improving the versatility and reliability of the cell housing and providing a strong guarantee for the safe operation of the power battery. Attached Figure Description

[0032] Figure 1 This is a three-dimensional structural diagram of the first embodiment of the explosion-proof valve patch in Example 1, taken from a first angle.

[0033] Figure 2 This is a two-dimensional structural diagram of the explosion-proof valve patch in the first embodiment of Example 1, where the X direction refers to the length direction of the substrate (along the maximum extension dimension of the substrate), the Y direction refers to the width direction of the substrate (perpendicular to the length direction and located in the plane of the substrate), and the Z direction refers to the thickness direction of the substrate (perpendicular to the plane of the substrate, representing the thickness of the substrate).

[0034] Figure 3 This is a top view of the first embodiment of the explosion-proof valve patch in Example 1;

[0035] Figure 4This is a three-dimensional structural diagram of the first angle of the second embodiment of the explosion-proof valve patch in Example 2, where the X direction refers to the length direction of the covering area (extending along the periphery of the substrate), the Y direction refers to the thickness direction of the covering area (radial dimension in the plane of the substrate), and the Z direction refers to the height direction of the covering area (extending dimension perpendicular to the plane of the substrate).

[0036] Figure 5 This is a two-dimensional structural diagram of the second embodiment of the explosion-proof valve patch in Example 2, taken from a second angle.

[0037] Figure 6 This is a top view schematic diagram of the second embodiment of the explosion-proof valve patch in Example 2.

[0038] In the picture:

[0039] 1. Matrix; 2. Adhesive layer; 3. Ventilation groove; 4. Covering area. Detailed Implementation

[0040] The present invention will be further described below with reference to specific embodiments.

[0041] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0042] Example 1

[0043] The explosion-proof valve patch in this embodiment, such as Figure 1-3 As shown, it includes a substrate 1 and an adhesive layer 2 applied to the annular region surrounding the substrate 1.

[0044] The substrate 1 can be made of PET (polyethylene terephthalate), PP (polypropylene), PE (polyethylene), or PI (polyimide). In this embodiment, the substrate 1 is made of PET, which appears as a blue transparent film with a thickness of 0.2 mm. In other embodiments, thicknesses of 0.15 mm to 0.25 mm achieve good technical results. The substrate 1 must be flat, smooth, free of burrs, material shortages, and deformation to ensure that the resulting explosion-proof valve patch does not leak. Simultaneously, the outer surface of the explosion-proof valve patch must be kept clean and free of dirt.

[0045] In this embodiment, the thickness of adhesive layer 2 is 0.1 mm. In practice, thicknesses of 0.05 mm to 0.2 mm can achieve good technical results. In this embodiment, the material of adhesive layer 2 is 3M 467. 3M 467 is a substrate-free double-sided adhesive from 3M, made by direct coating of acrylic adhesive. The tape is transparent and belongs to the 3M 200MP series. This adhesive layer is relatively thin, but still has excellent adhesion, prevents peeling, has excellent waterproof performance, good processability, good temperature resistance, and good holding power. In other embodiments, the material of adhesive layer 2 can also be DSTT-10M.

[0046] A permeable groove 3 is formed on the substrate 1, extending through its thickness. In this embodiment, there are four permeable grooves 3, each 0.3mm × 0.3mm in size, located at the center of the substrate 1, with their positions being centrally symmetrical and interconnected. In other embodiments, the number of permeable grooves 3 can be set from 1 to 9, with dimensions from 0.1mm to 5mm, depending on the permeability requirements, and they can also be designed independently.

[0047] A covering area 4 is provided around the periphery of the substrate 1, completely covering the periphery of the substrate 1. The thickness of the covering area 4 is equal to the thickness of the substrate 1, both being 0.2 mm, and the height is 0.7 mm. The back side of the covering area 4 is coated with the same adhesive layer 2 as the annular area around the substrate to enhance adhesion strength. In this embodiment, the back side of the covering area 4 is the side facing the substrate 1 in the semi-open space structure formed by the covering area 4 and the substrate 1. In other embodiments, the back side of the covering area 4 may optionally not be coated with the adhesive layer 2, depending on the actual installation requirements and application scenario.

[0048] A release paper is also provided on the side of the adhesive layer 2 away from the substrate 1. In this embodiment, the release paper is a polymer-coated waterproof kraft paper that will not wrinkle in a high-humidity environment; it has good temperature resistance, can withstand high temperatures for a long time, and can withstand high temperatures for a short time.

[0049] The explosion-proof valve patch prepared in this embodiment can effectively prevent sharp objects from damaging the explosion-proof valve or foreign objects, dust, etc. from falling into the explosion-proof valve and affecting the appearance of the battery, and it is waterproof and breathable. A sealed space with air is formed between the explosion-proof valve, the explosion-proof valve patch, and the top cover. During the vacuum baking test of the battery, the air between the three can be removed by the vacuum machine through the vent groove 3, which will not cause the internal air pressure to be greater than the external air pressure. Thermal expansion and contraction will not cause the protective film to wrinkle or deform, the explosion-proof valve patch will not fail, and there will be no residual adhesive at the explosion-proof valve.

[0050] The explosion-proof valve patch prepared in this embodiment exhibits excellent adhesion at high temperatures and resistance to electrolyte corrosion without delamination. This explosion-proof valve patch can be applied to battery cell housings. In this embodiment, the substrate 1 is generally elliptical in shape.

[0051] Example 2

[0052] The explosion-proof valve patch in this embodiment is basically the same as in embodiment 1, except that: a covering area 4 is provided around the periphery of the substrate 1, and the covering area 4 only partially covers the two long sides of the substrate 1, such as... Figure 4-6 As shown. Specifically, the covering area 4 is arranged around the two long sides of the substrate 1, forming a semi-open spatial structure. The substrate 1 has a ventilation groove 3 that runs through its thickness direction. In this embodiment, there are 4 ventilation grooves 3, each with a size of 0.3mm × 0.3mm, located at the center of the substrate 1. Their positions are symmetrical and they are designed independently of each other.

[0053] This invention provides an explosion-proof valve patch and its application. Through innovative structural design, it effectively solves the problems existing in the prior art and significantly improves the protective performance and reliability of the explosion-proof valve.

[0054] In Example 1, the full-coverage design, with the covered area surrounding the entire perimeter of the substrate, comprehensively enhances the adhesive strength and stability of the patch. This design is particularly suitable for scenarios with high protection requirements for explosion-proof valves, effectively preventing damage to the valves due to external impacts or contamination. Simultaneously, the venting groove design regulates the pressure difference within the confined space, ensuring the reliability of the patch and the normal operation of the explosion-proof valve under complex working conditions.

[0055] In Example 2, a partial encapsulation design is used, with encapsulation areas only provided on the two long sides of the elliptical substrate. This design reduces material usage while still providing sufficient adhesive strength and protection, making it particularly suitable for applications with high space requirements. The partial encapsulation design not only optimizes the overall structure of the battery cell housing but also reduces production costs while ensuring the protection performance of the explosion-proof valve.

[0056] Both embodiments employ an optimized venting groove design, allowing for flexible adjustment of the number, size, and layout of the venting grooves according to ventilability requirements, ensuring effective balance of internal pressure under various operating conditions. Furthermore, the material selection and structural design of the patch have undergone rigorous consideration to ensure its durability and reliability in complex environments such as high temperature and high humidity.

[0057] Through the above design, the anti-detachment patch of this utility model can effectively prevent sharp objects from damaging the explosion-proof valve or foreign objects, dust, etc. from falling into the explosion-proof valve, ensuring the safety and reliability of the battery. At the same time, the patch's waterproof and breathable properties, as well as its good high-temperature resistance and corrosion resistance, make it suitable for various application scenarios, providing a strong guarantee for the safe operation of the power battery.

[0058] In summary, the anti-detachment patch of this utility model has a reasonable design, strong functionality, and wide adaptability. It has significant innovation and practicality, can effectively improve the protection performance of explosion-proof valves, reduce battery safety risks, and has broad application prospects.

Claims

1. An explosion-proof valve patch, comprising a substrate (1) and an adhesive layer (2) applied to an annular region surrounding the substrate (1); wherein the substrate (1) has a permeable groove (3) extending through its thickness direction, characterized in that: The substrate (1) is further provided with a covering area (4) around its periphery. The covering area (4) is arranged around the periphery of the substrate (1), and the covering area (4) covers the periphery of the substrate (1) in a way that partially or completely covers it. The back of the covering area (4) may be selectively coated with or not coated with the same adhesive layer (2) as the annular area around the substrate (1).

2. The explosion-proof valve patch according to claim 1, characterized in that: The thickness of the covering region (4) is equal to the thickness of the substrate (1).

3. The explosion-proof valve patch according to claim 1, characterized in that: The height of the covered area (4) is 0.2 mm to 2 mm.

4. The explosion-proof valve patch according to claim 1, characterized in that: The thickness of the covering area (4) is 0.05 to 5.0 mm.

5. The explosion-proof valve patch according to any one of claims 1-4, characterized in that: The thickness of the substrate (1) is 0.15 mm to 0.25 mm; the thickness of the adhesive layer (2) is 0.05 mm to 0.2 mm.

6. The explosion-proof valve patch according to claim 5, characterized in that: The ventilation grooves (3) can be set in 1 to 9 according to the ventilation level requirements, and they can be designed to be independent or connected to each other; the positions of the ventilation grooves (3) are symmetrical to each other; the size of the ventilation grooves (3) is 0.1mm to 5mm.

7. The explosion-proof valve patch according to claim 5, characterized in that: The adhesive layer (2) is in the form of a grid.

8. The explosion-proof valve patch according to claim 5, characterized in that: The substrate (1) and / or the coating area (4) are made of PET, PP, PE or PI; the adhesive layer (2) is made of 3M467 or DSTT-10M.

9. The explosion-proof valve patch according to claim 5, characterized in that: The adhesive layer (2) is further provided with release paper on the side away from the substrate (1).

10. A battery cell casing, characterized in that: Includes the explosion-proof valve patch as described in any one of claims 1-9.

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