Insulation structure for lithium battery

Abstract

The utility model provides an insulation structure for a lithium battery, which comprises a back film and a release film, the release film comprises a film body and a tearing lug, the film body is connected with the back film in a sticking manner, and the tearing lug is connected with one end of the film body in the length direction; the end, close to the tearing lug, of the film body is provided with a notch, and the edge of the back film covers at least part of the notch. According to the utility model, the problems in the prior art that the release film of the top insulation sheet and the gum PC sheet are unreasonably combined, so that the initial stripping force generated during stripping of the release film is large, and the phenomenon that the release film cannot be normally stripped easily occurs are solved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and more specifically, to an insulating structure for lithium batteries. Background Technology

[0002] In the prior art, the top insulating sheet of a lithium battery typically includes an adhesive PC sheet and a release film. The size of the release film is equal to or slightly larger than that of the adhesive PC sheet. To facilitate the effective peeling of the release film from the adhesive PC sheet, tear tabs are usually provided at the edges of the release film. However, the existing bonding method between the release film and the adhesive PC sheet of the top insulating sheet is unreasonable, resulting in a large initial peeling force generated during peeling, which easily leads to the release film failing to peel off properly. Utility Model Content

[0003] The main purpose of this utility model is to provide an insulating structure for lithium batteries, so as to solve the problem that the bonding method between the release film of the top insulating sheet and the adhesive PC sheet in the prior art is unreasonable, which leads to a large initial peeling force when the release film is peeled off, and the release film is prone to failure to peel off properly.

[0004] To achieve the above objectives, this utility model provides an insulating structure for lithium batteries, including an adhesive backing sheet and a release film. The release film includes a film body and a tear tab. The film body is bonded to the adhesive backing sheet, and the tear tab is connected to one end of the film body along its length. The film body has a cut at the end near the tear tab, and the edge of the adhesive backing sheet covers at least part of the cut.

[0005] In an exemplary embodiment, the cut is a closed through hole formed on the membrane body and extending through both sides of the membrane body in the thickness direction.

[0006] In one exemplary embodiment, the extension direction of the cut is parallel to the tearing direction of the tear ear; or, the extension direction of the cut is set at an angle to the tearing direction of the tear ear.

[0007] In one exemplary embodiment, the cuts are a plurality of spaced-apart cuts, at least two of which extend in different directions; or, the cut is a single cut that extends continuously in the same direction; or, the cut is a single cut that extends continuously in different directions.

[0008] In one exemplary embodiment, there are two cuts, which are shaped like the number eight and extend outwards in a direction away from the tear tab. At least a portion of the cuts are covered by the adhesive backing sheet, and the included angle A between the extension directions of the two cuts satisfies: A≤60°; or, there are two cuts, which are spaced apart in the width direction of the film body and both cuts extend along the tear direction of the tear tab, and at least a portion of the cuts are covered by the adhesive backing sheet.

[0009] In an exemplary embodiment, there are two cuts, which are shaped like the number eight and extend outwards in a direction away from the tear. The distance L2 between each cut and the end edge of the membrane body on one side of the length direction satisfies: L2≤4mm.

[0010] In an exemplary embodiment, the cut is a strip that extends continuously along the width direction of the film body and is completely covered by the backing sheet; the extension length W3 of the cut in the width direction of the film body satisfies: 0.5W1≤W3≤0.7W1, where W1 is the width of the backing sheet.

[0011] In an exemplary embodiment, the cut is U-shaped and extends continuously along the length direction of the membrane body, the width direction of the membrane body, and the length direction of the membrane body, and at least the portion of the cut extending along the length direction of the membrane body is covered by the backing sheet; the extension length W3 of the cut in the width direction of the membrane body satisfies: 0.5W1≤W3≤0.7W1, where W1 is the width of the backing sheet.

[0012] In an exemplary embodiment, the distance L2 between the cut and the end edge of the membrane body on one side of the length direction satisfies: L2 = (L - L1) / 2mm, where L is the length of the membrane body and L1 is the length of the backing sheet.

[0013] In an exemplary embodiment, the thickness of the release film ranges from 0.05 to 0.15 mm; and / or, the width W2 of the tear tab satisfies: 10 mm ≤ W2 < W1, where W1 is the width of the adhesive backing sheet.

[0014] The present invention provides an insulating structure for lithium batteries, comprising an adhesive backing sheet and a release film. The release film comprises a film body and a tear tab. The film body is bonded to the adhesive backing sheet, and the tear tab is connected to one end of the film body along its length. The film body has a cut at one end near the tear tab, and the edge of the adhesive backing sheet covers at least part of the cut.

[0015] By setting a slit at one end of the film body near the tear tab, and having the edge of the backing sheet cover at least part of the slit, the initial peel force of the release film is reduced during the tearing process along the tearing direction, thereby improving the yield of the production line. The slit not only simplifies the peeling process and avoids abnormalities in the release film due to excessive peeling force, but also ensures the stability and reliability of the insulation structure during use. In addition, the limited location of the slit ensures the reliability and convenience of the release film peeling, greatly reducing the difficulty of peeling the release film. Furthermore, by having the edge of the backing sheet cover at least part of the slit, the connection between the backing sheet and the film body is made easier to peel off during the release film peeling process due to the presence of the slit. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0017] Figure 1 A schematic diagram of the insulation structure according to Embodiment 1 of the present invention is shown from a first side view, in which the adhesive backing sheet is located above the release film.

[0018] Figure 2 It shows Figure 1 A magnified structural diagram at point B in the diagram;

[0019] Figure 3 It shows Figure 1 A schematic diagram of the insulation structure from a second side view, in which the release film is located above the backing film;

[0020] Figure 4 It shows Figure 3 A magnified structural diagram at point C;

[0021] Figure 5 A schematic diagram of the insulation structure according to Embodiment 2 of the present invention is shown from a first side view, in which the adhesive backing sheet is located above the release film;

[0022] Figure 6 It shows Figure 5 A schematic diagram of the insulation structure from a second side view, in which the release film is located above the backing film;

[0023] Figure 7 It shows Figure 6 A magnified structural diagram at point D in the diagram;

[0024] Figure 8A schematic diagram of the insulation structure according to Embodiment 3 of the present invention is shown from a first side view, in which the adhesive backing sheet is located above the release film;

[0025] Figure 9 It shows Figure 8 A magnified structural diagram at point E in the diagram;

[0026] Figure 10 It shows Figure 8 A schematic diagram of the insulation structure from a second side view, in which the release film is located above the backing film;

[0027] Figure 11 It shows Figure 10 A magnified structural diagram at point F in the diagram.

[0028] The above figures include the following reference numerals:

[0029] 10. Adhesive backing film;

[0030] 20. Release membrane; 21. Membrane body; 211. Cut; 22. Ear tear. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0032] To address the problem in existing technologies where the bonding method between the release film and the adhesive PC sheet on the top insulating sheet is unreasonable, resulting in a large initial peeling force during the peeling process and making it difficult to peel off the release film properly, this invention provides an insulating structure for lithium batteries.

[0033] Example 1

[0034] like Figures 1 to 4 As shown, the insulating structure for lithium batteries includes an adhesive backing sheet 10 and a release film 20. The release film 20 includes a film body 21 and a tear tab 22. The film body 21 is bonded to the adhesive backing sheet 10, and the tear tab 22 is connected to one end of the film body 21 along its length. The film body 21 has a cut 211 at the end near the tear tab 22, and the edge of the adhesive backing sheet 10 covers at least part of the cut 211.

[0035] By providing a slit 211 at one end of the film body 21 near the tear tab 22, and having the edge of the backing sheet 10 cover at least part of the slit 211, the initial peeling force of the release film 20 is reduced during the tearing process of the tear tab 22 along the tearing direction, thereby improving the yield of the production line. The slit 211 not only simplifies the peeling process and avoids abnormalities in the release film 20 due to excessive peeling force, but also ensures the stability and reliability of the insulation structure during use. In addition, the limited location of the slit 211 ensures the reliability and convenience of peeling the release film 20, greatly reducing the difficulty of peeling the release film 20. Furthermore, by having the edge of the backing sheet 10 cover at least part of the slit 211, the connection between the backing sheet 10 and the film body 21 is made easier to peel off during the peeling process of the release film 20 due to the presence of the slit 211.

[0036] It should be noted that in this application, the cut 211 is a closed through hole formed on the membrane body 21 and extending through both sides of the membrane body 21 in the thickness direction. This ensures that the cut 211 does not extend to the outer periphery of the membrane body 21, thus preventing the release film 20 from being torn or becoming difficult to peel off during the peeling process. When peeling is performed using the tear tab 22, the design at the cut 211 greatly reduces the difficulty of peeling off the release film 20.

[0037] like Figures 1 to 4 As shown, the extension direction of the cut 211 is set at an angle to the tearing direction of the tear tab 22. In this way, by setting the extension direction of the cut 211 at an angle to the tearing direction of the tear tab 22, convenience is ensured during the process of peeling off the release film 20.

[0038] It should be noted that in this embodiment, there are multiple cuts 211 spaced apart, and at least two of the multiple cuts 211 have different extension directions.

[0039] Specifically, such as Figures 1 to 4As shown, there are two cuts 211, which are in the shape of an octagon. The two cuts 211 extend outward in the direction away from the tear tab 22. At least part of the cuts 211 are covered by the adhesive backing sheet 10. The included angle A between the extension directions of the two cuts 211 satisfies: A≤60°. By arranging the two cuts 211 in a figure-eight shape, the peeling force of the tear tab 22 is further reduced, while ensuring the stability of the tear tab 22 during the peeling process. This prevents the tear tab 22 from being torn or damaged due to improper design of the cuts 211. On high-speed automated production lines, this design also ensures the smooth peeling of the release film 20, improving production yield. This is especially important in automated production lines for lithium battery manufacturing, where rapid and continuous peeling of the release film 20 is required. This design can significantly improve production efficiency and reliability. In addition, by limiting the range of the included angle A between the two cuts 211, the stress distribution of the cuts 211 on the film body 21 can be optimized, avoiding unnecessary stress concentration during the peeling process, thereby reducing the peeling force and minimizing damage to the material near the cuts 211. During the peeling operation, not only is the peeling force reduced, but the integrity of the release film 20 and the backing sheet 10 is also guaranteed, further improving the reliability and consistency of the product. In the production of various types of lithium batteries, especially for high-precision and high-requirement battery manufacturing, this control of the cut angle is particularly important.

[0040] like Figure 4 As shown, there are two cuts 211, which are V-shaped and extend outwards away from the tear tab 22. The distance L2 between each cut 211 and the end edge of the membrane body 21 along its length satisfies: L2 ≤ 4 mm. By optimizing the range of L2 between each cut 211 and the end edge of the membrane body 21 along its length, the peeling force can be reduced while avoiding excessively deep cuts 211 that could affect the backing film 10 and thus the performance of the entire insulation structure. This makes the peeling operation easier, while ensuring that the electrical insulation performance and mechanical strength of the product are not affected, thus ensuring the safety and durability of the lithium battery. From consumer electronics to electric vehicles and other lithium battery applications, this optimized design of the cut depth 211 can adapt to the needs of different scenarios and improve the overall quality of the battery product.

[0041] Example 2

[0042] It should be noted that, in this embodiment, the difference from Embodiment 1 is that the cut 211 is a single cut that extends continuously in the same direction.

[0043] like Figures 5 to 7As shown, the cut 211 extends continuously along the width direction of the membrane body 21 and is strip-shaped, and the cut 211 is completely covered by the backing sheet 10; the extension length W3 of the cut 211 in the width direction of the membrane body 21 satisfies: 0.5W1≤W3≤0.7W1, where W1 is the width of the backing sheet 10. This provides a clear starting point for the peeling operation, improving its accuracy and controllability, making the peeling operation easier, reducing the possibility of operational errors, and improving production efficiency and product qualification rate. Especially in the lithium battery assembly process, particularly in the stage where precise peeling of the release film 20 is required, this design can significantly improve the convenience and success rate of the operation. In addition, by reasonably optimizing the range of the extension length W3 of the cut 211 in the width direction of the film body 21, a certain proportional relationship is maintained between the cut 211 and the width of the backing sheet 10. This can effectively adjust the peeling force, while ensuring that the cut 211 is not too close to the center area of ​​the backing sheet 10, avoiding affecting the adhesion performance of the backing layer of the backing sheet 10. This makes the peeling process smoother and avoids problems such as peeling difficulties or poor adhesion of the backing layer caused by improper placement of the cut 211. Especially in the automated assembly line of lithium battery production, this precise length control of the cut 211 can meet the requirements of high-speed and high-precision production, improving overall production efficiency and product quality.

[0044] Example 3

[0045] It should be noted that, in this embodiment, the difference from Embodiment 1 is that the cut 211 is a single cut that extends continuously in different directions.

[0046] like Figures 8 to 11 As shown, the cut 211 extends continuously in a U-shape along the length direction, width direction, and length direction of the membrane body 21, and at least the portion of the cut 211 extending along the length direction of the membrane body 21 is covered by the backing sheet 10. The extension length W3 of the cut 211 in the width direction of the membrane body 21 satisfies: 0.5W1≤W3≤0.7W1, where W1 is the width of the backing sheet 10. This ensures that during the peeling of the release film 20, the transverse portion of the cut 211 can serve as a guide line for peeling, reducing peeling force. Furthermore, since the depth of the cut 211 is variable, it can be flexibly adjusted according to different production needs and equipment conditions to achieve the best peeling effect, making the peeling operation easier and the product more adaptable, meeting the requirements of different production environments. Especially in the production, assembly, and maintenance of lithium batteries, this U-shaped cut 211 design significantly improves the convenience and flexibility of operation, increasing production efficiency and product qualification rate.

[0047] It should be noted that in this embodiment, the U-shaped opening of the U-shaped cut 211 faces away from the tear ear 22, that is, the actual shape of the cut 211 in this embodiment is "[".

[0048] like Figure 11 As shown, the distance L2 between the cut 211 and the end edge of the membrane body 21 along its length satisfies: L2 = (L - L1) / 2mm, where L is the length of the membrane body 21 and L1 is the length of the backing sheet 10. By optimizing the range of the distance L2 between the cut 211 and the end edge of the membrane body 21 along its length, the peeling force can be reduced while preventing the cut 211 from being too deep and affecting the backing sheet 10, thus impacting the performance of the entire insulation structure. This makes the peeling operation easier, while ensuring that the electrical insulation performance and mechanical strength of the product are not affected, thus ensuring the safety and durability of the lithium battery. From consumer electronics to electric vehicles and other lithium battery applications, this optimized design of the cut 211 depth can adapt to the needs of different scenarios and improve the overall quality of battery products.

[0049] Example 4

[0050] It should be noted that in an embodiment not shown in this application, the difference from Embodiment 1 is that there are two cuts 211, which are spaced apart in the width direction of the film body 21, and both cuts 211 extend along the tearing direction of the tear tab 22, with at least a portion of the cuts 211 covered by the backing sheet 10. By extending both cuts 211 along the tearing direction of the tear tab 22, the peeling force of the tear tab 22 is further reduced, while ensuring the stability of the tear tab 22 during the peeling process. This avoids tearing or damage to the tear tab 22 due to improper design of the cuts 211. On high-speed automated production lines, this also ensures the smooth peeling of the release film 20, improving production yield. Especially in automated production lines during lithium battery manufacturing, where rapid and continuous peeling of the release film 20 is required, this design can significantly improve production efficiency and reliability. Furthermore, by covering at least a portion of the cuts 211 with the backing sheet 10, the peeling force of the release film 20 is reduced.

[0051] Furthermore, in this embodiment, the extending direction of the cut 211 is parallel to the tearing direction of the tear ear 22.

[0052] It should be noted that in all embodiments of this application, the cut 211 is only made on the release film 20.

[0053] It should be noted that in all embodiments of this application, the thickness of the release film 20 ranges from 0.05 to 0.15 mm; and / or, the width W2 of the tear tab 22 satisfies: 10 mm ≤ W2 < W1, where W1 is the width of the adhesive backing sheet 10.

[0054] It should be noted that in all embodiments of this application, the outer contour line of the backing sheet 10 coincides with the outer contour line of the film body 21 in the thickness direction of the release film 20; or, in the thickness direction of the release film 20, the outer contour line of the backing sheet 10 is located within the outer contour line of the film body 21.

[0055] It should be noted that in all embodiments of this application, the adhesive backing sheet 10 is an adhesive-backed PC sheet.

[0056] The present invention provides an insulating structure for lithium batteries, comprising an adhesive backing sheet 10 and a release film 20. The release film 20 comprises a film body 21 and a tear tab 22. The film body 21 is bonded to the adhesive backing sheet 10, and the tear tab 22 is connected to one end of the film body 21 along its length. The end of the film body 21 near the tear tab 22 has a cut 211, and the edge of the adhesive backing sheet 10 covers at least part of the cut 211.

[0057] By providing a slit 211 at one end of the film body 21 near the tear tab 22, and having the edge of the backing sheet 10 cover at least part of the slit 211, the initial peeling force of the release film 20 is reduced during the tearing process of the tear tab 22 along the tearing direction, thereby improving the yield of the production line. The slit 211 not only simplifies the peeling process and avoids abnormalities in the release film 20 due to excessive peeling force, but also ensures the stability and reliability of the insulation structure during use. In addition, the limited location of the slit 211 ensures the reliability and convenience of peeling the release film 20, greatly reducing the difficulty of peeling the release film 20. Furthermore, by having the edge of the backing sheet 10 cover at least part of the slit 211, the connection between the backing sheet 10 and the film body 21 is made easier to peel off during the peeling process of the release film 20 due to the presence of the slit 211.

[0058] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0059] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0060] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0061] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0062] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0063] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An insulating structure for lithium batteries, characterized in that, include: Adhesive backing sheet (10); Release film (20), the release film (20) includes a film body (21) and a tear tab (22), the film body (21) is bonded to the adhesive backing sheet (10), and the tear tab (22) is connected to one end of the film body (21) in the length direction; The membrane body (21) has a cut (211) at one end near the tear tab (22), and the edge of the backing sheet (10) covers at least part of the cut (211).

2. The insulation structure according to claim 1, characterized in that, The cut (211) is a closed through hole formed on the membrane body (21) and extending through both sides of the membrane body (21) in the thickness direction.

3. The insulation structure according to claim 1, characterized in that, The extension direction of the cut (211) is parallel to the tearing direction of the tear (22); or, The extension direction of the cut (211) is set at an angle to the tearing direction of the tear ear (22).

4. The insulation structure according to claim 1, characterized in that, The cuts (211) are multiple and spaced apart, and at least two of the cuts (211) extend in different directions; or, The cut (211) is a single cut that extends continuously in the same direction; or, The cut (211) is a continuous one extending in different directions.

5. The insulation structure according to claim 1, characterized in that, There are two cuts (211), which are shaped like the number eight. Each cut (211) extends outwards in a direction away from the tear tab (22). At least a portion of each cut (211) is covered by the adhesive backing sheet (10). The included angle A between the extending directions of the two cuts (211) satisfies: A ≤ 60°; or... There are two cuts (211), which are spaced apart in the width direction of the membrane body (21) and both cuts (211) extend along the tearing direction of the tear tab (22). At least part of the cuts (211) are covered by the adhesive backing sheet (10).

6. The insulation structure according to claim 1, characterized in that, There are two cuts (211), which are shaped like the number eight. The two cuts (211) extend outward in a direction away from the tear (22). The distance L2 between each cut (211) and the end edge of the membrane body (21) on one side of the length direction satisfies: L2≤4mm.

7. The insulation structure according to claim 1, characterized in that, The cut (211) extends continuously along the width direction of the membrane body (21) and is strip-shaped, and the cut (211) is completely covered by the adhesive backing sheet (10); The extension length W3 of the cut (211) in the width direction of the membrane body (21) satisfies: 0.5W1≤W3≤0.7W1, where W1 is the width of the backing sheet (10).

8. The insulation structure according to claim 1, characterized in that, The cut (211) extends continuously along the length direction of the membrane body (21), the width direction of the membrane body (21), and the length direction of the membrane body (21) in a U-shape, and at least the portion of the cut (211) extending along the length direction of the membrane body (21) is covered by the backing film (10). The extension length W3 of the cut (211) in the width direction of the membrane body (21) satisfies: 0.5W1≤W3≤0.7W1, where W1 is the width of the backing sheet (10).

9. The insulation structure according to claim 7 or 8, characterized in that, The distance L2 between the cut (211) and the end edge of the membrane body (21) on one side of the length direction satisfies: L2=(L-L1) / 2mm, where L is the length of the membrane body (21) and L1 is the length of the backing sheet (10).

10. The insulating structure according to any one of claims 1 to 8, characterized in that, The thickness of the release film (20) ranges from 0.05 to 0.15 mm; and / or, The width W2 of the tear tab (22) satisfies: 10mm≤W2<W1, where W1 is the width of the adhesive backing sheet (10).

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