Battery cell insulation wrapping film with limiting punching structure

Abstract

The utility model discloses a battery core insulation wrapping film with a limiting punching structure, which realizes accurate limiting and final locking of a film in the wrapping process through the design of limiting holes corresponding to convex parts such as a positive pole column and a negative pole column at the top of a battery core, avoids the traditional complex process depending on an adhesive or a fixing clamp, and improves the production efficiency. And the production process is simplified. And the convex part of the battery cell is naturally limited and matched with the coating film, so that the coating stability is improved, and the quality problems of membrane displacement, wrinkling and the like are also reduced. According to the design, the dependence on material characteristics is reduced, the design flexibility and adaptability of the diaphragm are enhanced, the problems of aging and degumming of a fixing device in a traditional process are avoided, the long-term use reliability and safety of the battery cell are improved, the defects in the prior art are overcome, and a more efficient and more reliable solution is provided for insulation coating of the battery cell.

Description

Technical Field

[0001] The utility model relates to the technical field of battery core insulation coating and packaging, in particular to a battery core insulation wrapping film with a limiting punching structure. Background Art

[0002] With the widespread adoption of electric vehicles and energy storage devices, lithium-ion batteries, as their core components, are facing increasingly stringent requirements for insulation, thermal insulation, and safety. To ensure good electrical performance and mechanical strength during operation, batteries are typically coated with an insulating film to prevent internal short circuits, intrusion from the external environment, and other physical damage.

[0003] In existing technology, the common coating method is to fix the insulating wrap film to the surface of the battery cell using adhesive or mechanical clamps. This method relies on the adhesive adhesion and the high elasticity of the film to ensure that the film adheres tightly to the battery cell. However, this method has the following major problems:

[0004] 1. The adhesive may age after long-term use, causing the diaphragm to separate from the battery surface, thereby affecting the insulation performance and mechanical strength of the battery.

[0005] 2. The adhesive coating and curing process is complex, increasing production costs and difficulty. In addition, the use of mechanical fixtures may increase the volume and weight of the battery cell, which is not suitable for lightweight design requirements.

[0006] To address adhesive aging and unstable fixation, some industry technologies have adopted more complex multi-layer coating designs or incorporated reinforcing materials into the film to improve its durability. However, these solutions not only increase material costs and complicate the process, but because the film relies on the inherent properties of the material for fixation, they still cannot effectively prevent problems such as film shifting and wrinkling during use.

[0007] To further improve the coating effect and simplify the process, the industry has also attempted to enhance the fixing effect by adjusting the coating film adhesion process and applying higher pressure or temperature. However, this approach can easily lead to uneven force on the diaphragm, causing localized warping or deformation of the diaphragm, affecting the heat dissipation performance and service life of the battery cell. In addition, over-reliance on the adhesion process also limits material selection and cannot flexibly adapt to the structure and requirements of different battery cells.

[0008] Therefore, how to simplify the battery core coating process and improve the fixing stability of the coating film and the battery core surface has become a technical problem to be solved by the present utility model. Utility Model Content

[0009] The technical problem solved by the present invention is to provide a battery cell insulation wrapping film with a limited punching structure in response to the defects existing in the above-mentioned prior art, so as to solve the problems of complex existing battery cell coating process, unstable film fixation and limited material selection raised in the above-mentioned background technology.

[0010] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0011] A battery cell insulation wrapping film with a limited punching structure, comprising a wrapping film body, a first battery cell top wrapping film sheet, and a second battery cell top wrapping film sheet;

[0012] The first battery cell top wrapping film, the second battery cell top wrapping film and the wrapping film body are an integrated structure;

[0013] The first battery cell top wrapping film and / or the second battery cell top wrapping film are respectively provided with limiting holes;

[0014] The first cell top wrapping film and the second cell top wrapping film are respectively fixedly connected to two sides of the wrapping film body;

[0015] When the wrapping film body is wrapped around the battery cell, the wrapping film sheet on the top of the first battery cell and / or the wrapping film sheet on the top of the second battery cell are connected to the raised portion on the top of the battery cell through the limiting hole;

[0016] The limiting fitting connection is that the first battery cell top wrapping film and / or the second battery cell top wrapping film are sleeved on the raised portion through the limiting hole.

[0017] As a further solution of the present invention, the raised portion at least includes a positive electrode column and a negative electrode column at the top of the battery cell.

[0018] As a further solution of the present invention, the wrapping film body, the first battery cell top wrapping film sheet and the second battery cell top wrapping film sheet are all made of a multi-layer composite material, and the multi-layer composite material includes a PET film, a pressure-sensitive adhesive layer and a release film layer.

[0019] As a further solution of the present invention, the first battery cell top wrapping film and the second battery cell top wrapping film are integrally formed by a die-cutting process, and reserved creases are set at the positions connected to the wrapping film body to facilitate accurate folding and positioning during the wrapping process.

[0020] As a further solution of the present invention, the surface of the film wrapping the top of the first battery cell and / or the film wrapping the top of the second battery cell has a micro-convex texture to enhance the contact stability between the film and the battery cell surface.

[0021] As a further solution of the present invention, the limiting holes are matched with the raised parts, that is, the first battery cell top wrapping film and / or the second battery cell top wrapping film are respectively provided with limiting holes corresponding to each raised part on the top of the battery cell and matched with each raised part.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. Utilizing raised portions for final locking and improved wrapping stability: By designing limiting holes on the wrapping film that correspond to the raised portions on the top of the cell, the wrapping film is precisely positioned and locked, tightly bonding the wrapping film to the raised portions on the top of the cell, creating a stable mechanical locking effect. This design does not rely on traditional additional fixing components or bonding processes, but instead securely locks the wrapping film through the cell's own structure, eliminating the risk of the film loosening or shifting, and significantly improving the overall wrapping stability and durability.

[0024] 2. No additional fixing devices or complex adhesives are required, simplifying the process: This utility model uses the natural limiting and locking effect of the coating film and the raised portion of the battery cell to eliminate the traditional complex steps that require additional adhesives and fixing fixtures, making the battery cell coating process simpler and more efficient. The elimination of additional fixing steps not only simplifies the process and reduces production difficulty, but also avoids subsequent problems that may occur due to adhesive aging or loosening of fixings, thereby improving production efficiency and product reliability.

[0025] 3. Reduced reliance on diaphragm material properties, enhancing design flexibility: Traditional technologies typically rely on the adhesion of specific materials and the high elasticity of the diaphragm to achieve coating stability. However, this utility model effectively reduces reliance on the physical properties of the diaphragm material through the limited locking design of the raised portion. This structural locking allows for greater flexibility in the choice of coating film, allowing for the use of a variety of material combinations to enhance the product's heat resistance, pressure resistance, and heat dissipation performance.

[0026] 4. Avoiding displacement and wrinkling during traditional coating processes, improving product consistency: By limiting the raised portion and locking the diaphragm, this utility model effectively avoids quality issues such as displacement and wrinkling caused by uneven force or loose adhesion in traditional coating methods. The limiting and locking makes the coating process more stable and controllable, ensuring the smoothness and consistency of contact between the diaphragm and the battery surface, improving the overall appearance quality and safety of the battery cell.

[0027] 5. Eliminate the need for subsequent maintenance associated with traditional fixing methods, improving long-term reliability: After the final locking connection is formed between the cell's own structure and the coating, no additional adhesive maintenance or inspection is required. This reduces quality risks associated with the cell during long-term use and significantly improves the product's long-term reliability. Problems such as debonding and aging that are common with traditional fixing methods are completely avoided with this new design, providing more durable and stable coating protection for the cell.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0030] Figure 1 It is a structural diagram of a battery cell in the prior art.

[0031] Figure 2 for Figure 1 A structural diagram of the wrapping film body of the present invention when the outer side of the battery cell is wrapped.

[0032] Figure 3 This is a schematic diagram of the structure of the wrapping film body of the utility model Figure 1 .

[0033] Figure 4 This is a schematic diagram of the structure of the wrapping film body of the utility model Figure 2 .

[0034] Figure 5 This is a schematic diagram of the structure of the wrapping film body of the utility model Figure 3 .

[0035] Figure 6 This is a structural schematic diagram of the insulating wrapping film of the present invention when it is a multi-layer composite structure.

[0036] Figure 7 This is a flow chart of a method for wrapping a battery cell insulation wrapping film with a limited punching structure according to the present invention.

[0037] The reference numerals and names in the figures are as follows:

[0038] Wrapping film body 1, first battery cell top wrapping film sheet 2, second battery cell top wrapping film sheet 3, limiting hole 4, battery cell 5, raised portion 6 and fold 7. DETAILED DESCRIPTION

[0039] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] See also Figure 1 —6. In an embodiment of the present invention, a battery cell insulating wrapping film with a limited perforated structure includes a wrapping film body 1, and also includes a first battery cell top wrapping film sheet 2 and a second battery cell top wrapping film sheet 3;

[0041] The first cell top wrapping film 2, the second cell top wrapping film 3 and the wrapping film body 1 are an integrated structure;

[0042] The first battery cell top wrapping film 2 and / or the second battery cell top wrapping film 3 are respectively provided with limiting holes 4;

[0043] The first cell top wrapping film 2 and the second cell top wrapping film 3 are fixedly connected to both sides of the wrapping film body 1 respectively;

[0044] When the wrapping film body 1 is wrapped around the battery cell 5, the wrapping film sheet 2 on the top of the first battery cell and / or the wrapping film sheet 3 on the top of the second battery cell are connected to the raised portion 6 on the top of the battery cell 5 through the limiting holes 4. That is, all the raised portions 6 on the top of the battery cell 5 have corresponding limiting holes 4. The limiting and fitting connection is that the wrapping film sheet 2 on the top of the first battery cell and / or the wrapping film sheet 3 on the top of the second battery cell are placed on the raised portion 6 through the limiting holes 4. The raised portion 6 includes at least the positive and negative electrode columns at the top of the battery cell.

[0045] The wrapping film body 1, the first battery cell top wrapping film sheet 2 and the second battery cell top wrapping film sheet 3 are all made of a multi-layer composite material, and the multi-layer composite material includes a PET film, a pressure-sensitive adhesive layer and a release film layer. As a further solution of the present invention, the first battery cell top wrapping film sheet 2 and the second battery cell top wrapping film sheet 3 are integrally formed by a die-cutting process, and a reserved fold 7 is set at the position connected to the wrapping film body 1 to facilitate accurate folding and positioning during the wrapping process. The surface of the first battery cell top wrapping film sheet 2 and / or the second battery cell top wrapping film sheet 3 has a slightly convex texture to enhance the contact stability between the film and the battery cell surface; wherein, the method of wrapping the battery cell 5 by the fold 7 can be understood as a prior art, and belongs to a method known to ordinary technicians in this field. The distinguishing feature of the present invention is that the locking fit is achieved through the limiting hole 4. The wrapping membrane 2 on the top of the first battery cell and / or the wrapping membrane 3 on the top of the second battery cell are designed according to the various raised parts 6 on the top of the battery cell, and corresponding limiting holes 4 are respectively set for the raised parts 6 including but not limited to the positive electrode column, the negative electrode column, the explosion-proof membrane, the injection hole and the QR code platform, so that the wrapping membrane 2 fits tightly with the top of the battery cell 5 on each raised part 6.

[0046] A method for wrapping a battery core insulating wrapping film with a limited punching structure comprises the following steps:

[0047] Step 1: According to the arrangement of the raised parts 6 at various parts of the top of the battery cell, the punching position and number of the coating film are designed to form the punching limit holes 4 that adapt to the shape of the battery cell to ensure accurate positioning during the coating process;

[0048] Step 2: unfold the insulating film and align it with the battery cell 5, so that each limiting hole 4 matches and limits the corresponding raised portion 6 on the top of the battery cell 5 to ensure that the film is accurately positioned on the surface of the battery cell;

[0049] Step 3: Apply pressure, heat treatment or bonding operation to the insulating coating film to make the membrane fit tightly to the surface of the battery cell and achieve limited fit between the membrane and the raised portion 6 on the top of the battery cell;

[0050] Step 4: Shape and fix the coated battery cell to prevent the coating film from shifting, loosening or wrinkling, so as to ensure the consistency and flatness of the battery cell coating.

[0051] During the design process of step 1, by detecting the specific size, position and shape of each raised part 6 on the top of the battery cell, the limiting holes on the coating film are precisely designed and adjusted to ensure that the limiting holes match the raised parts 6 on the top of the battery cell, so that battery cells of different types and specifications can achieve precise limiting and stable fitting effects during coating.

[0052] In step 3, the coating is applied by setting a specific temperature range and pressure value, with the temperature range being 60°C to 150°C and the pressure being 0.1 to 1.0 MPa, to ensure that the coating film is heated evenly and the pressure is moderate during the coating process, thereby achieving stable adhesion between the diaphragm and the surface of the battery cell and avoiding detachment, displacement or warping of the diaphragm.

[0053] The shaping and fixing treatment in step 4 is performed by gradually applying a uniform pressure of 0.05 to 0.5 MPa or using vacuum adsorption technology at an adsorption force of -0.1 to -0.8 MPa to ensure that the diaphragm is fully and stably attached to the surface of the battery cell, eliminating air or gaps between the diaphragm and the battery cell, avoiding warping, bulging and loosening in local areas, and ensuring the consistency and flatness of the coating.

[0054] It also includes step 5, adjusting the covering and folding method of the coating film in different areas of the battery cell to optimize the fitting effect of the diaphragm in key parts such as the top and sides, thereby improving the heat dissipation and durability of the battery cell; wherein, the adjustment and folding method in step 5 includes precise cutting of the edges and corners of the coating film to remove excess material, controlled stretching of the areas to be bent to relieve stress concentration, and overlapping the edges of the diaphragm on the side walls and top of the battery cell, and fixing them by local heating or pressing to ensure smooth connection of various parts of the diaphragm after coating, thereby avoiding cracking or deformation of the diaphragm due to stress concentration.

[0055] Example 1:

[0056] This embodiment provides a specific application of a battery cell insulation wrapping film with a limited perforation structure and a wrapping method thereof, which is particularly suitable for improving the insulation protection and structural stability of battery cells in electric vehicle battery wrapping scenarios.

[0057] In the current electric vehicle industry, to ensure the insulation, protection, and thermal management performance of battery cells, an insulating film is typically applied to the outer surface of the cell. However, existing coating methods often use adhesive bonding or mechanical clamping. These methods are subject to issues such as adhesive aging, film displacement, and complex production processes, which limit the safety and service life of the battery cells. To this end, this embodiment provides a specific implementation method for coating battery cells in electric vehicles.

[0058] In this example, a standard square lithium-ion battery cell is first selected. The top of the cell is provided with a raised portion 6, including a positive electrode column, a negative electrode column, an explosion-proof membrane, and a liquid injection port. Traditionally, the insulation protection of the battery cell is typically achieved by manually attaching an insulating film to the cell surface, which is then secured with an adhesive for curing or a mechanical clamp. However, this method often causes the film to separate from the cell due to aging and instability of the adhesive, compromising the safety of the cell and the stability of the overall structure.

[0059] To address this issue, this embodiment utilizes an insulating coating with a perforated structure. This coating is a composite of a PET film, a pressure-sensitive adhesive layer, and a release film layer, and exhibits excellent insulation, heat resistance, and mechanical protection. The diaphragm is designed as an integrated structure, comprising a wrapping film body 1, a wrapping film 2 for the top of the first battery cell, and a wrapping film 3 for the top of the second battery cell. The diaphragm is also pre-set with perforated holes corresponding to the raised portions 6 of the battery cells, specifically holes for the positive and negative electrode posts, the explosion-proof membrane, and the injection port.

[0060] In actual use, the film is first precisely cut using a die-cutting machine, ensuring that the position and size of the retaining holes perfectly match the raised portion 6 on the top of the cell. The cut film is then unfolded and aligned with the cell, ensuring that the retaining holes precisely fit over the raised portion 6 on the top of the cell. At this point, the film, naturally restrained by the cell, is quickly secured and positioned, eliminating the need for additional adhesive or clamps.

[0061] Next, the already positioned cover film is subjected to appropriate heat treatment and pressure to further secure it to the cell surface. Specifically, the film is uniformly pressed through a hot press at a temperature of 80°C to 120°C and a pressure of 0.2 to 0.6 MPa, ensuring close contact and final locking between the cover film and the cell. This process utilizes the raised portion 6 on the top of the cell to create a natural locking effect, effectively avoiding the problems of film displacement, warping, or wrinkling in traditional processes.

[0062] The innovation of this embodiment lies in the precise positioning and natural locking of the film through the cooperation of the protrusion 6 of the battery cell itself and the limiting holes of the film, forming a new fixing method that does not require additional fixing devices. This method not only simplifies the process flow and reduces the dependence on adhesives and clamps, but also significantly improves the stability and long-term reliability of the film.

[0063] Application results show that this coating method can maintain a stable connection between the membrane and the battery cell over multiple charge and discharge cycles, without membrane displacement or loosening. Furthermore, through an optimized limiter design, the fit between the coating film and the battery cell is significantly improved, and overall heat dissipation performance is also enhanced. Compared with traditional methods, this new coating method not only improves the coating effect, but also achieves increased production efficiency and provides more durable and reliable protection for the battery cell.

[0064] Example 2:

[0065] This embodiment describes the application of a cell insulation wrap film in lithium battery production. This film is particularly suitable for insulation protection and thermal management optimization of square-shell cells used in new energy electric vehicles. Traditional square-shell cells are typically insulated using a blue film coating. The blue film is primarily used to cover multiple surfaces of the cell, including the main wall, side walls, and top surface, and is top-sealed using a black PC top patch. However, this method presents significant problems in practical applications. For example, the top patch increases material costs, the bonding process is complex, and it is difficult to fully protect the cell top cover, impacting the overall performance and heat dissipation of the cell.

[0066] This embodiment uses a multi-layer composite insulating coating film to replace the traditional blue film and black PC top sheet, significantly optimizing the battery cell coating process. The specific application steps are as follows:

[0067] First, a typical prismatic battery cell for new energy vehicles was selected. This cell features raised features such as a positive and negative electrode column, an explosion-proof membrane, a liquid injection port, and a QR code. 6 Traditional encapsulation methods require coating the five sides of the cell with blue film and then encapsulating the top surface with a separate black PC top sheet. This process is cumbersome and prone to problems such as a loose fit between the top sheet and the cell cover, resulting in insufficient protection and compromising the cell's insulation and heat dissipation performance.

[0068] The insulating film of this utility model is a multi-layer composite structure, comprising an outer PET film layer, an interlayer pressure-sensitive adhesive layer, and an inner PET film layer. A die-cutting process precisely reserves holes at both ends of the film corresponding to the top structure of the battery cell. In actual use, the double-layer insulating film is unfolded and applied to the surface of the battery cell housing. The precise design of the hole positions ensures that the film sheets overlap and fit in the top cover area, eliminating the need for a traditional top sheet.

[0069] During the wrapping process, the film first covers all surfaces of the cell. The overlapping double-layer film at the top cover provides natural positioning and physical locking, forming a continuous protective layer that significantly enhances the voltage tolerance and physical protection of the top cover. Furthermore, the overlapping double-layer film design shifts the crease (7) that may occur during the wrapping process from the cell bottom to the sidewalls, streamlining the heat transfer path between the cell bottom and the liquid cooling plate and optimizing heat dissipation.

[0070] Compared to existing technologies, the coating method in this embodiment eliminates the black PC top sheet and directly utilizes the overlapping structure of the cell top cover and double-layer coating film, reducing overall material costs, simplifying the production process, and avoiding the risk of the top sheet not being firmly attached. Furthermore, the diaphragm's position-limiting design ensures that the coated cell maintains a tight fit between the diaphragm and the cell even under complex operating conditions such as high voltage and severe vibration, making it less likely to shift or fall off, thereby enhancing the overall safety and reliability of the cell.

[0071] In the present invention, unless otherwise clearly stipulated and limited, the terms "install", "set", "connect", "fix", "screw" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; 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 connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0072] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced within the present invention.

Claims

1. A battery core insulation wrapping film with a limited perforation structure, comprising a wrapping film body, characterized in that: Also included is a first battery cell top wrapping film and a second battery cell top wrapping film; The first battery cell top wrapping film, the second battery cell top wrapping film and the wrapping film body are an integrated structure; The first battery cell top wrapping film and / or the second battery cell top wrapping film are respectively provided with limiting holes; The first cell top wrapping film and the second cell top wrapping film are respectively fixedly connected to two sides of the wrapping film body; When the wrapping film body is wrapped around the battery cell, the wrapping film sheet on the top of the first battery cell and / or the wrapping film sheet on the top of the second battery cell are connected to the raised portion on the top of the battery cell through the limiting hole; The limiting fitting connection is that the first battery cell top wrapping film and / or the second battery cell top wrapping film are sleeved on the raised portion through the limiting hole.

2. The battery core insulating wrapping film with a limited perforation structure according to claim 1, characterized in that: The raised portion includes at least the positive electrode column and the negative electrode column at the top of the battery cell.

3. The battery core insulating wrapping film with a limited perforation structure according to claim 1, characterized in that: The wrapping film body, the first battery cell top wrapping film sheet and the second battery cell top wrapping film sheet are all made of a multi-layer composite material, and the multi-layer composite material includes a PET film, a pressure-sensitive adhesive layer and a release film layer.

4. The battery core insulating wrapping film with a limited perforation structure according to claim 1, characterized in that: The first cell top wrapping film and the second cell top wrapping film are integrally formed through a die-cutting process, and a reserved crease is set at the position where they are connected to the wrapping film body to facilitate accurate folding and positioning during the wrapping process.

5. The battery core insulation wrapping film with a limited perforation structure according to claim 1, characterized in that: The surface of the film wrapping the top of the first battery cell and / or the film wrapping the top of the second battery cell has a micro-convex texture to enhance the contact stability between the film and the surface of the battery cell.

6. The battery core insulation wrapping film with a limited perforation structure according to claim 1, characterized in that: The limiting holes match the raised portions, that is, the first battery cell top wrapping film and / or the second battery cell top wrapping film are respectively provided with limiting holes corresponding to the raised portions on the top of the battery cells and matching the raised portions.

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