Edge sealing tape for soft package battery cell and soft package battery cell

Abstract

The utility model provides a kind of edge sealing tape for soft package battery and soft package battery;The edge sealing tape includes: tape base body and adhesive layer;Adhesive layer is arranged on the surface of tape base body, and is used to paste cover the edge of soft package battery and the surface area of soft package battery connected with edge;Edge sealing tape includes at least one first subzone covering edge and at least one second subzone covering surface area arranged alternately;The gray value of first subzone is higher than the gray value of second subzone, and the gray value of first subzone is 30 and above higher than the gray value of the soft package battery area covered by it;The gray value of second subzone is 15 and above higher than the gray value of the soft package battery area covered by it, which can improve the technical problem of low accuracy rate of edge defect detection.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a sealing tape for soft-pack battery cells and a soft-pack battery cell. Background Technology

[0002] With the rapid development of electronic devices, pouch cells are widely used in various electronic products due to their advantages such as thinness, lightness, and high energy density. Pouch cells typically use aluminum-plastic film as packaging material, and their structure includes the cell body and side folded edges. During the manufacturing process of pouch cells, the side folded edges need to be secured to ensure the cell's safety.

[0003] Currently, the edges of soft-pack battery cells are fixed by applying multiple layers of adhesive along their length. This method cannot completely restrain the aluminum-plastic film at the edges. When the film lifts, the edge extends beyond the height of the battery cell itself, hindering module assembly. Furthermore, the sharp edges of the aluminum-plastic film at the edges pose a risk of puncturing other battery cells. To address these issues, another solution is to cover the entire edge with tape. However, this method, covering the entire edge area, results in low accuracy in detecting side defects. Utility Model Content

[0004] This invention provides an edge-sealing tape for soft-pack battery cells and a soft-pack battery cell, in order to improve the technical problem of low accuracy in detecting edge folding defects.

[0005] This utility model provides an edge-sealing tape for pouch cells. The edge-sealing tape includes: a tape substrate and an adhesive layer; the adhesive layer is disposed on the surface of the tape substrate and is used to adhere and cover the folded edge of the pouch cell and the surface area of ​​the pouch cell connected to the folded edge; the edge-sealing tape includes at least one first section covering the folded edge and at least one second section covering the surface area, which are alternately arranged; the gray value of the first section is higher than the gray value of the second section, and the gray value of the first section is 30 or more higher than the gray value of the pouch cell area it covers; the gray value of the second section is 15 or more higher than the gray value of the pouch cell area it covers.

[0006] In one embodiment of the present invention, the sealing tape has a first direction extending in the same direction as the extension direction of the folded edge and a second direction perpendicular to the first direction; a first partition and a second partition are arranged along the second direction, both the first partition and the second partition extending along the first direction, the first partition corresponding to cover at least a portion of the folded edge, and the second partition located on one or both sides of the first partition along the second direction.

[0007] In one embodiment of the present invention, the minimum peel strength of the sealing tape is greater than or equal to 1.5 N / cm, and the initial circumferential tack of the sealing tape is 0.5 to 5 N / cm.

[0008] In one embodiment of this utility model, the material of the tape substrate is one of polyethylene terephthalate, polypropylene, and polyimide; the material of the adhesive layer is one of polyacrylate pressure-sensitive adhesive, rubber pressure-sensitive adhesive, and silicone pressure-sensitive adhesive.

[0009] In one embodiment of the present invention, at least the tape substrate and / or adhesive layer located in the second partition contains a colorant, which is an organic pigment or an inorganic pigment.

[0010] In one embodiment of this utility model, the maximum thickness of the sealing tape is less than or equal to 60 μm.

[0011] This utility model also provides a soft-pack battery cell, which includes the sealing tape of any of the above, and the folded edge of the soft-pack battery cell and the surface area of ​​the soft-pack battery cell connected to the folded edge are covered with the sealing tape.

[0012] In one embodiment of the present invention, along the extension direction of the folded edge, both ends of the sealing tape extend beyond the two ends of the folded edge, and the portions of the sealing tape extending beyond the folded edge are self-adhesive to seal the edge. The length of the sealing tape is L, and the length of the folded edge is L1, where 5mm ≤ L - L1 ≤ 10mm.

[0013] In one embodiment of the present invention, the soft-pack battery cell includes two oppositely arranged folded edges, which are respectively located on a first side and a second side arranged oppositely. The first side and the second side are connected by a first surface and a second surface arranged oppositely. Two sealing tapes respectively cover the first side and the second side and extend to the first surface and the second surface. The area covered by the sealing tapes is the surface area. At least a portion of the first section of the sealing tape is bonded to the folded edge, and the second section of the sealing tape is bonded to the first surface and / or the second surface.

[0014] In one embodiment of the present invention, the sealing tape includes two second sections, which are respectively connected to both sides of the first section along a direction perpendicular to the folded edge. Both the first section and the second section extend along the extension direction of the folded edge, and the width of the second section along the extension direction perpendicular to the folded edge is greater than or equal to 4 mm.

[0015] The beneficial effects of this utility model are as follows: This utility model proposes an edge-sealing tape that can wrap the folded edge and the connected surface area, providing an insulating protective layer for the folded edge of the soft-pack battery cell. This design eliminates the risk of the folded edge scratching other battery cells, suppresses edge springback and warping, and is beneficial for subsequent module and battery pack assembly.

[0016] The sealing tape comprises alternating first and second sections. The first section covers the folded edge and has a grayscale value 30 or higher than the grayscale value of the covered pouch cell area to form a light-transmitting observation window, facilitating the identification of defects or foreign objects inside the folded edge. The second section covers the surface area connected to the folded edge, with a grayscale value lower than the first section but 15 or higher than the grayscale value of the covered pouch cell area, providing positioning marks for the visual inspection system. This structure allows the sealing tape to provide both physical protection and defect observation and visual positioning functions, improving the accuracy and efficiency of folded edge defect detection. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] In the attached diagram:

[0019] Figure 1 This is a schematic diagram of the structure of the sealing tape provided in one embodiment of the present utility model;

[0020] Figure 2 This is a top view of the sealing tape provided in one embodiment of the present utility model.

[0021] Figure 3 This is a schematic diagram of the structure of a pouch cell provided in one embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the structure of a pouch cell provided in one embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the structure of a pouch cell provided in one embodiment of the present invention;

[0024] Figure 6 This is a schematic diagram of the structure of a pouch cell provided in a pair of proportions of this utility model.

[0025] The attached figures are labeled as follows:

[0026] 100. Edge sealing tape; 110. Tape substrate; 120. Adhesive layer; 130. First section; 140. Second section; 200. Soft-pack battery cell; 210. Surface area; 211. First side; 212. Second side; 220. First surface; 230. Second surface; 240. Folded edge; 250. Tab; 300. Whole pack of tape. Detailed Implementation

[0027] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0028] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0029] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0030] Please see Figure 1 and Figure 2 This utility model provides an edge-sealing tape 100 for a soft-pack battery cell 200 and a soft-pack battery cell 200. The edge-sealing tape 100 includes at least one first section 130 covering the folded edge 240 and at least one second section 140 covering the surface area 210. The edge-sealing tape 100 can completely wrap the folded edge 240 while improving the positioning accuracy and the accuracy of detecting defects in the folded edge 240.

[0031] The sealing tape 100 includes a tape substrate 110 and an adhesive layer 120. The adhesive layer 120 is disposed on the surface of the tape substrate 110 and is used to adhere to the surface area 210 of the flexible battery cell 200 connected to the folded edge 240. In one embodiment, the flexible battery cell 200 includes two opposing folded edges 240, which are located on opposing first side 211 and second side 212, respectively. The first side 211 and second side 212 are connected by opposing first surface 220 and second surface 230. The surface area 210 includes either the first side 211 or the second side 212, but is not limited to the first side 211 and the second side 212. It may also include a portion of the first surface 220 and the second surface 230 adjacent to the first side 211 and the second side 212.

[0032] The shape of the tape substrate 110 is not limited, as long as it can completely cover the folded edge 240 of the soft-pack battery cell 200. The shape of the adhesive layer 120 is also not limited; it can be coated entirely on the tape substrate 110, or partially or in a patterned manner. In one embodiment, the tape substrate 110 is rectangular, and the adhesive layer 120 is coated entirely on the tape substrate 110. This configuration can completely cover the folded edge 240, solving the problems of edge curling and sharp edges.

[0033] In one embodiment of this utility model, please refer to Figure 2 The sealing tape 100 includes at least one first section 130 covering the folded edge 240 and at least one second section 140 covering the surface area 210, which are alternately arranged. It should be noted that the first section 130 covering the folded edge 240 means that the first section 130 is located above the folded edge 240; however, the first section 130 may cover the entire folded edge 240, or it may only cover part of the folded edge 240, which is not limited. Similarly, the second section 140 covering the surface area 210 means that the second section 140 is located above the surface area 210; however, the first section 130 may cover the entire surface area 210, or it may only cover part of the surface area 210, which is not limited. The number of first sections 130 and second sections 140 is not limited; for example, there may be one or more of both. The first section 130 and the second section 140 can be partitioned by setting differences in optical properties, different physical structures, or patterns. The above differences can be achieved by setting differences on the tape substrate 110, on the adhesive layer 120, or on a composite structure of the two.

[0034] In some embodiments, the position information of the second section 140 of the sealing tape 100 is acquired through a machine vision inspection device. Based on the position information, automatic optical inspection is performed on the folded edge 240 of the battery cell. For example, a CCD camera (Charge-Coupled Device Camera) is used for inspection. This inspection first determines the coordinates of the entire sealing tape 100 and the battery folded edge 240 by identifying the precise position of the second section 140. After successful positioning, the camera is triggered to take a high-resolution picture to acquire a clear image of the folded edge 240. The software performs noise reduction, contrast enhancement, and edge sharpening on the acquired image to improve the recognizability of the features. Finally, the processed image is analyzed by an algorithm to measure the size of the sealing tape 100 and detect defects in the folded edge 240.

[0035] Based on this, in this embodiment, the grayscale value of the first partition 130 is set to be higher than that of the second partition 140. This setting allows the first partition 130 to have higher transparency than the second partition 140, and also provides contrast between the first partition 130 and the second partition 140. Further, the grayscale value of the first partition 130 is set to be 30 or more higher than the grayscale value of the area of ​​the pouch cell 200 it covers. This difference of more than 30 grayscale values ​​creates a high-transmittance observation window in the first partition 130, allowing the imaging light from the CCD camera to penetrate the first partition 130 and capture the microscopic features inside the folded edge 240 covering it, thereby improving detection accuracy. The grayscale value of the second partition 140 is 15 or more higher than the grayscale value of the area of ​​the pouch cell 200 it covers. This setting allows the second partition 140 to form a stable and sufficient contrast with the surface area 210 of the pouch cell 200 it covers, ensuring that the CCD camera can quickly, stably, and accurately identify and capture data on a high-speed production line. The grayscale contrast between the first partition 130 and the second partition 140 forms a clear functional boundary in the image. This design enables the image processing algorithm to distinguish between the detection area and the localization area, thereby improving the accuracy of localization and increasing the accuracy of detecting defects at the folded edge 240.

[0036] Please see Figure 2 In one embodiment of this utility model, the sealing tape 100 has a first direction extending in the same direction as the extension direction of the folded edge 240 (as shown by X in the figure) and a second direction perpendicular to the first direction (as shown by Y in the figure); the first partition 130 and the second partition 140 are arranged along the second direction, and both the first partition 130 and the second partition 140 extend along the first direction. This arrangement facilitates the first partition 130 to cover the folded edge 240, so that the folded edge 240 can have a larger area to be detected, thereby improving the detection accuracy. The second partition 140 is located on one or both sides of the first partition 130 along the second direction. In one embodiment, a second partition 140 is provided, and the second partition 140 is located on either side of the first partition 130. In another embodiment, as shown in the figure... Figure 2 As shown, there are two second partitions 140, which are located on both sides of the first partition 130. This setting adds the option of positioning reference and can realize positioning recognition on both sides of the first partition 130, further improving the accuracy and adaptability of positioning.

[0037] Please see Figure 2In one embodiment of this utility model, the minimum peel strength of the sealing tape 100 is greater than or equal to 1.5 N / cm. This limitation ensures that even the location with the lowest peel strength in the sealing tape 100 can be above 1.5 N / cm, thus ensuring sufficient and lasting adhesion of the tape to the folded edge 240 of the battery cell, forming a stable bond to the folded edge 240 area. The annular initial tack of the sealing tape 100 is limited to 0.5–5 N / cm. The annular initial tack measures the adhesion ability of the adhesive layer 120 at the moment of contact. An annular initial tack greater than or equal to 0.5 N / cm allows the sealing tape 100 to be quickly positioned, and then the adhesive force increases over time, eventually reaching a higher peel strength for permanent fixation. It should be noted that on automated production lines, the sealing tape 100 is typically picked up from the roll of material by a vacuum suction cup or gripper, pulled out, and transferred to the bonding station. If the initial tack of the tape exceeds 5 N / cm, its excessive instantaneous tack will cause the tape to accidentally stick to the sidewalls of the grippers or suction cups during transfer, instead of remaining stably in the intended position. This invention, by setting the initial tack to be less than or equal to 5 N / cm, can improve the abnormal adhesion of the tape to the tooling fixtures, ensuring the continuity and stability of the automated production process. Furthermore, the unwinding strength of the roll tape ranges from 0.1 to 5 N / cm. An unwinding strength greater than or equal to 0.1 N / cm can prevent the tape from unwinding. An unwinding strength less than or equal to 5 N / cm facilitates the operation of the grippers pulling the tape apart, and meeting this range ensures high stability of the roll during unwinding.

[0038] Please see Figure 2 In one embodiment of this utility model, the material of the tape substrate 110 can be selected from various options and is not limited thereto, such as polyethylene terephthalate (PET), polypropylene (PP), and polyimide (PI). The material of the adhesive layer 120 can be selected from various options and is not limited thereto, such as polyacrylate pressure-sensitive adhesive, rubber pressure-sensitive adhesive, and silicone pressure-sensitive adhesive.

[0039] Please see Figure 2To achieve different grayscale values ​​for the second partition 140 and the first partition 130, in one embodiment of this invention, at least the tape substrate 110 and / or adhesive layer 120 located in the second partition 140 contain a colorant. This can be achieved by mixing the colorant only into the tape substrate 110, only into the adhesive layer 120, or by mixing the colorant into both the tape substrate 110 and the adhesive layer 120. It should be noted that the first partition 130 and the second partition 140 can be differentiated by mixing different colored colorants, or by mixing the colorant only into one of the second partitions 140. Many materials can be selected for the colorant, including organic pigments and inorganic pigments. Organic materials include, but are not limited to, phthalocyanine blue, phthalocyanine green, and benzimidazolone pigments, while inorganic materials include, but are not limited to, cobalt blue and cobalt green.

[0040] Please see Figure 2 In one embodiment of this utility model, the maximum thickness of the sealing tape 100 is less than or equal to 60 μm. This design achieves an ultra-thin and lightweight overall design for the sealing tape 100. This design allows the sealing tape 100 to perform the functions of edge folding 240 fixing and detection while minimizing its occupation of the internal space of the battery module, thereby improving the overall energy density of the battery system.

[0041] Please see Figure 2 In one embodiment of this utility model, the minimum thickness of the tape substrate 110 is greater than or equal to the maximum thickness of the adhesive layer 120. This arrangement ensures that the tape substrate 110, as a supporting skeleton, has sufficient mechanical strength, and also reduces the overflow of the adhesive layer 120 during the bonding process, thereby improving the bonding quality of the sealing tape 100.

[0042] Please see Figure 2In one embodiment of this utility model, the thickness of the adhesive tape substrate 110 ranges from 15 to 35 μm, which provides ideal basic stiffness and mechanical strength for the sealing tape 100. The thickness of the adhesive layer 120 located in the second partition 140 is defined as 5 to 30 μm. The second partition 140 is both a positioning area and an adhesive area. By configuring the adhesive layer 120 with a thickness of 5 to 30 μm, sufficient and uniform adhesive strength is ensured between the sealing tape 100 and the soft-pack battery folded edge 240, achieving a firm fixing effect. Furthermore, the physical difference in thickness between the adhesive layer 120 and the first partition 130 provides additional identification features for CCD detection positioning. The thickness of the adhesive layer 120 located in the first partition 130 ranges from 0 to 30 μm. The first zone 130 is the detection zone. By using an extremely thin adhesive layer 120, or even no adhesive layer, combined with a thin adhesive tape substrate 110, the blocking and scattering effect of the adhesive layer 120 on light is minimized, ensuring that the CCD camera or human vision can clearly observe the microscopic defects inside the folded edge 240, thus improving the accuracy and reliability of internal detection.

[0043] Please see Figures 3 to 6 This utility model also provides a soft-pack battery cell 200, which includes a battery cell and an aluminum-plastic film. The battery cell has two tabs 250 at both ends. The aluminum-plastic film is configured to have a sealed receiving space, the battery cell is located within the receiving space and tightly adhered to the aluminum-plastic film, and the two tabs 250 are located outside the aluminum-plastic film. The soft-pack battery cell 200 also includes the aforementioned sealing tape 100, with the sealing tape 100 covering the folded edge 240 of the soft-pack battery cell 200 and the surface area 210 of the soft-pack battery cell 200 connected to the folded edge 240. This not only completely covers the folded edge 240, but also improves the positioning accuracy and the accuracy of detecting defects in the folded edge 240.

[0044] Please see Figure 4 and Figure 5 In one embodiment of this utility model, along the extending direction of the folded edge 240, both ends of the sealing tape 100 extend beyond the folded edge 240. The portions of the sealing tape 100 extending beyond the folded edge 240 are self-adhesive to seal the edge. This arrangement achieves a better sealing effect, blocking the path of electrolyte capillary seepage from the ends of the folded edge 240. The length of the sealing tape 100 is L, and the length of the folded edge 240 is L1, where 5mm ≤ L - L1 ≤ 10mm. Limiting the length to this range achieves both enhanced mechanical fixing of the sealing tape 100, preventing the folded edge 240 from springing back and loosening, and avoids excessive length that increases space occupation.

[0045] Please see Figure 4 and Figure 5In one embodiment of this utility model, the soft-pack battery cell 200 includes two opposing folded edges 240, which are located on a first side 211 and a second side 212 respectively. Neither the first side 211 nor the second side 212 has tabs 250. The first side 211 and the second side 212 are connected by opposing first surfaces 220 and second surfaces 230. Two sealing tapes 100 respectively cover the first side 211 and the second side 212 and extend onto the first surface 220 and the second surface 230. The area covered by the sealing tapes 100 is the surface area 210. This bonding method forms a clamping structure, improving the bonding strength of the sealing tapes 100. At least a portion of the first section 130 of the sealing tapes 100 is bonded to the folded edge 240. This arrangement ensures that the observation window for internal defect detection is precisely positioned directly above the folded edge 240 that needs to be monitored most. The second section 140 of the sealing tape 100 is adhered to the first surface 220 and / or the second surface 230. This arrangement places the second section 140 for CCD positioning on the flat, open first surface 220 and / or second surface 230 of the pouch cell 200. This provides the vision inspection system with a stable, unobstructed, and easily identifiable gripping plane, improving the speed, accuracy, and stability of positioning.

[0046] Please see Figure 4 and Figure 5 In one embodiment of the present invention, the sealing tape 100 includes two second sections 140. The two second sections 140 are respectively connected to both sides of the first section 130 along the wrapping direction of the sealing tape 100. Both the first section 130 and the second section 140 extend along the extension direction of the folded edge 240. The width of the second section 140 along the extension direction perpendicular to the extension direction of the folded edge 240 is greater than or equal to 4mm.

[0047] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention. The technical solution was tested through comparative examples and several preferred embodiments. One hundred battery cells with foreign objects / defects at the folded edge 240 position and normal tape dimensions were selected. Then, sealing tape 100 was wrapped around the folded edge 240 position. After wrapping, the battery cells were placed under a CCD for photographic recognition, and the results of corresponding size detection and foreign object / defect detection were recorded, as shown in Table 1.

[0048] Table 1 shows the results of dimensional inspection and foreign object / defect inspection for Comparative Examples 1-3 and Examples 1-3.

[0049]

[0050] The present technical solution will be described in detail below with reference to Table 1, through three comparative examples and three preferred embodiments.

[0051] Comparative Example 1:

[0052] For the use of undivided, full-pack 300 g tape, please refer to [link / reference]. Figure 6 The tape substrate 110 is made of PET, and the adhesive layer 120 is made of polyacrylic acid. The thickness of the tape substrate 110 is 25μm, and the thickness of the adhesive layer 120 is 10μm. The total width of the entire package of tape 300 is 70mm. The peel strength is 2.5N / cm, the initial tack is 2.7N / cm, and the unwinding strength is 3.0N / cm. The grayscale difference between the entire package of tape 300 and the aluminum-plastic film is 10. The accuracy rate for identifying the dimensions of the entire package of tape 300 in Comparative Example 1 is 9%, and the accuracy rate for detecting foreign objects / defects is 3%.

[0053] Comparative Example 2:

[0054] For the use of undivided, whole-pack tape 300, please refer to [link / reference]. Figure 6 The tape substrate 110 is PET, and the adhesive layer 120 is polyacrylic acid-based. The thickness of the tape substrate 110 is 25μm, and the thickness of the adhesive layer 120 is 10μm. The total width of the sealing tape 100 is 70mm. The peel strength is 4.0N / cm, the initial tack is 3.8N / cm, and the unwinding strength is 3.0N / cm. The grayscale value difference between the entire package of tape 300 and the aluminum-plastic film is 20. In this comparative example 2, the grayscale value difference between the entire package of tape 300 and the aluminum-plastic film exceeds 15. The accuracy rate of identifying the size of the entire package of tape 300 reaches 100%. However, the accuracy rate of foreign object / defect detection is still low, at 11%.

[0055] Comparative Example 3:

[0056] Please refer to sectioned edge sealing tape 100. Figure 2 The tape substrate 110 is PET, and the adhesive layer 120 is polyacrylic acid-based. The tape substrate 110 is 25μm thick, and the adhesive layer 120 is 10μm thick. The total width of the sealing tape 100 is 26mm, the width W2 of the two second sections 140 is 3mm, and the width W1 of the first section 130 is 20mm. The peel strength is 2.8N / cm, the initial tack is 2.6N / cm, and the unwinding strength is 2.3N / cm. The grayscale difference between the second section 140 and the aluminum-plastic film is 20, and the grayscale difference between the first section 130 and the aluminum-plastic film is also 20. In this comparative example 3, the grayscale difference between the entire package of tape 300 and the aluminum-plastic film exceeds 15, and the accuracy of identifying the size of the sealing tape 100 reaches 100%. However, the grayscale difference between the first section 130 and the aluminum-plastic film is less than 30, and the accuracy of foreign object / defect detection is still low, at 8%.

[0057] Example 1:

[0058] Please refer to sectioned edge sealing tape 100. Figure 2The tape substrate 110 is PET, and the adhesive layer 120 is polyacrylic acid-based. The tape substrate 110 is 25μm thick, and the adhesive layer 120 is 10μm thick. The total width of the sealing tape 100 is 26mm, the width W2 of the second section 140 is 3mm, and the width W1 of the first section 130 is 20mm. The peel strength is 3.2N / cm, the initial tack is 4.5N / cm, and the unwinding strength is 0.7N / cm. The grayscale difference between the second section 140 and the aluminum-plastic film is 20, and the grayscale difference between the first section 130 and the aluminum-plastic film is 40. In this embodiment 1, the grayscale difference between the second section 140 and the aluminum-plastic film exceeds 15, and the accuracy of identifying the size of the sealing tape 100 reaches 100%. Moreover, the grayscale difference between the first section 130 and the aluminum-plastic film is higher than 30, and the accuracy of foreign object / defect detection is 100%.

[0059] Example 2:

[0060] Please refer to sectioned edge sealing tape 100. Figure 2 The tape substrate 110 is made of polyimide (PI), and the adhesive layer 120 is made of silicone. The thickness of the tape substrate 110 is 20 μm, and the thickness of the adhesive layer 120 is 13 μm. The total width of the sealing tape 100 is 28 mm, the width W2 of the second section 140 is 4 mm, and the width W1 of the first section 130 is 20 mm. The peel strength is 3.0 N / cm, the initial tack is 3.6 N / cm, and the unwinding strength is 3.4 N / cm. The grayscale difference between the second section 140 and the aluminum-plastic film is 15, and the grayscale difference between the first section 130 and the aluminum-plastic film is 30. In this embodiment 2, the grayscale difference between the second section 140 and the aluminum-plastic film reaches 15, and the accuracy of identifying the size of the sealing tape 100 reaches 100%. Moreover, the grayscale difference between the first section 130 and the aluminum-plastic film reaches 30, and the accuracy of foreign object / defect detection reaches 100%.

[0061] Example 3:

[0062] Please refer to sectioned edge sealing tape 100. Figure 2The tape substrate 110 is PP, and the adhesive layer 120 is rubber. The thickness of the tape substrate 110 is 15μm, and the thickness of the adhesive layer 120 is 0μm, meaning there is no adhesive layer 120. The total width W of the sealing tape 100 is 30mm, the width W2 of the second section 140 is 5mm, and the width W1 of the first section 130 is 10mm. The peel strength is 1.8N / cm, the initial tack is 0.8N / cm, and the unwinding strength is 1.4N / cm. The grayscale difference between the second section 140 and the aluminum-plastic film is 20, and the grayscale difference between the first section 130 and the aluminum-plastic film is 50. In this embodiment 3, the grayscale difference between the second section 140 and the aluminum-plastic film exceeds 15, and the accuracy of identifying the size of the sealing tape 100 reaches 100%. Moreover, the grayscale difference between the first section 130 and the aluminum-plastic film exceeds 30, and the accuracy of foreign object / defect detection reaches 100%.

[0063] Examples 1-3 adopted the preferred scheme of this application, and all of them achieved the result of detecting all foreign objects / defects. Compared with comparative examples 1-3, this application improved the detection accuracy and improved the problem of missed detection.

[0064] This invention proposes a sealing tape that, through its design comprising a first section and a second section, completely covers the folded edge, solving the problems of edge curling and sharp edges. The second section enables positioning and identification, improving positioning accuracy. The first section enables side edge detection, facilitating the identification of defects in the side edges and folded edges, thereby improving the accuracy of defect detection.

[0065] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A sealing tape for soft-pack battery cells, characterized in that, include: Tape substrate; An adhesive layer is disposed on the surface of the tape substrate and is used to adhere and cover the folded edge of the soft-pack battery cell and the surface area of ​​the soft-pack battery cell connected to the folded edge; The edge sealing tape includes at least one first section that covers the folded edge and at least one second section that covers the surface area, which are alternately arranged. The grayscale value of the first partition is higher than that of the second partition. The grayscale value of the first partition is 30 or more higher than the grayscale value of the pouch cell area it covers. The grayscale value of the second partition is 15 or more higher than the grayscale value of the pouch cell area it covers.

2. The sealing tape according to claim 1, characterized in that, The sealing tape has a first direction extending in the same direction as the extension direction of the folded edge and a second direction perpendicular to the first direction; The first partition and the second partition are arranged along the second direction, and both the first partition and the second partition extend along the first direction. The second partition is located on one or both sides of the first partition along the second direction.

3. The sealing tape according to claim 1, characterized in that, The minimum peel strength of the sealing tape is greater than or equal to 1.5 N / cm, and the initial circumferential tack of the sealing tape is 0.5 to 5 N / cm.

4. The sealing tape according to claim 1, characterized in that, The tape substrate is made of one of polyethylene terephthalate, polypropylene, and polyimide. The adhesive layer is made of one of the following materials: polyacrylate pressure-sensitive adhesive, rubber pressure-sensitive adhesive, and silicone pressure-sensitive adhesive.

5. The sealing tape according to claim 1, characterized in that, At least the tape substrate and / or adhesive layer located in the second partition contain a colorant, which is an organic pigment or an inorganic pigment.

6. The sealing tape according to claim 1, characterized in that, The maximum thickness of the sealing tape is less than or equal to 60 μm.

7. A pouch cell, characterized in that, The sealing tape, as described in any one of claims 1 to 6, is used to cover the folded edge of the soft-pack battery cell and the surface area of ​​the soft-pack battery cell connected to the folded edge.

8. The soft-pack battery cell according to claim 7, characterized in that, Along the extension direction of the folded edge, both ends of the sealing tape extend beyond the two ends of the folded edge. The portions of the sealing tape extending beyond the folded edge are self-adhesive to seal the edge. The length of the sealing tape is L, and the length of the folded edge is L1, wherein 5mm ≤ L - L1 ≤ 10mm.

9. The soft-pack battery cell according to claim 8, characterized in that, The soft-pack battery cell includes two oppositely arranged folded edges, which are located on a first side and a second side respectively. The first side and the second side are connected by a first surface and a second surface respectively. Two sealing tapes cover the first side and the second side respectively and extend to the first surface and the second surface. The area covered by the sealing tapes is the surface area. Wherein, at least a portion of the first section of the sealing tape is adhered to the folded edge, and the second section of the sealing tape is adhered to the first surface and / or the second surface.

10. The soft-pack battery cell according to claim 9, characterized in that, The sealing tape includes two second sections, which are respectively connected to both sides of the first section along a direction perpendicular to the folded edge. Both the first section and the second section extend along the extension direction of the folded edge, and the width of the second section along the extension direction perpendicular to the folded edge is greater than or equal to 4 mm.

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