Battery cell cover plate insulating structure and battery cell

Abstract

The present application relates to the technical field of batteries, in particular to a battery cell cover plate insulating structure and a battery cell. The battery cell cover plate insulating structure comprises an insulating film, creases being formed on the insulating film so as to divide the insulating film into a first bonding portion, second bonding portions and third bonding portions; the second bonding portions and the third bonding portions are alternately arranged around the periphery of the first bonding portion; the first bonding portion is adhered to a cover plate; each second bonding portion is folded along a crease such that part of the second bonding portion is adhered to a first surface of a casing; each third bonding portion is folded along a crease such that the third bonding portion is adhered to a second surface of the casing. The present application can realize insulation protection for a cover plate, and allow part of the insulating film to be adhered to a casing of a battery cell, such that connection portions between the cover plate and the casing can be effectively covered, and the insulation effect satisfies battery pack-level requirements, thus achieving the purpose of reducing costs and improving efficiency. In addition, the bonding area is also increased and the bonding strength is improved, thus avoiding problems such as lifting and falling off, and ensuring the insulation effect of battery cells and the efficiency of battery cell production.

Description

Cell cover insulation structure and cell

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. CN202411442259.1, filed on October 16, 2024, entitled "Cell cover insulation structure and cell", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of battery technology, and in particular relates to a cell cover insulation structure and a cell. Background Technology

[0004] Lithium-ion batteries are widely used in various fields such as transportation power supplies, power storage, new energy storage power supplies, and aerospace and military industries due to their advantages such as large capacity, high operating voltage, strong charge retention, and long cycle life. The structure of a lithium-ion battery includes a cover plate, casing, electrode assembly, and electrolyte. External insulation of the casing is typically achieved through methods such as spraying insulating materials or wrapping with insulating tape, while insulation of the cover plate is usually achieved by attaching an insulating top cover patch.

[0005] Currently, in order to improve the overall energy density of battery packs, the thickness of individual cells is getting thinner and thinner, which makes the size of the cover plate smaller and smaller. In addition, the cover plate also integrates terminals, explosion-proof valves, cell temperature sensing areas, etc., which need to be avoided. This results in the effective bonding area between the insulating top cover patch and the cover plate becoming smaller and smaller. As a result, the problem of the insulating top cover patch lifting and falling off frequently occurs in the cell manufacturing process and subsequent assembly processes, which seriously affects the insulation effect of the cell and production efficiency.

[0006] Application content

[0007] In view of this, the purpose of this application is to provide a cell cover plate insulation structure and a cell to solve the problem that the cover plate insulation method of pasting insulating top cover patch is prone to the problem of patch lifting and falling off, which affects the insulation effect and production efficiency of the cell.

[0008] In a first aspect, this application provides an insulating structure for a battery cell cover, comprising an insulating film having creases formed on it to divide the insulating film into a first adhesive portion, a second adhesive portion, and a third adhesive portion;

[0009] The second adhesive portion and the third adhesive portion are alternately arranged around the circumference of the first adhesive portion; the first adhesive portion is attached to the cover plate, the second adhesive portion is bent along the crease so that a portion of the second adhesive portion is attached to the first surface of the housing, and the third adhesive portion is bent along the crease so that it is attached to the second surface of the housing.

[0010] Beneficial effects: It can achieve insulation protection for the cover plate and allow part of the insulating film to be attached to the battery cell casing, so that the connection between the cover plate and the casing can be effectively covered. The insulation effect meets the requirements of the whole package, achieving the purpose of cost reduction and efficiency improvement. In addition, it increases the bonding area and improves the bonding strength, avoiding problems such as lifting and falling off, and ensuring the insulation effect and production efficiency of the battery cell.

[0011] In one optional embodiment, the second adhesive part has a edging portion formed at its end in the first direction. After the second adhesive part is attached to the first surface, the second adhesive part is bent so that the edging portion is attached to the second surface.

[0012] In one alternative embodiment, the third adhesive portion is attached to the upper layer of the edge binding portion.

[0013] In one optional embodiment, a notch is provided between the edge binding portion and the third adhesive portion; before the second adhesive portion is bent, the length dimension of the notch in the first direction is H, 3mm≤H≤6mm, and the width dimension of the notch in the second direction is G, 0.2mm≤G≤0.3mm.

[0014] In one alternative embodiment, before bending along the crease, the second adhesive part has a dimension of E in the second direction, 2.5mm≤E≤10mm, and the third adhesive part has a dimension of F in the first direction, 2.5mm≤F≤10mm.

[0015] In one alternative implementation, E = F.

[0016] In one alternative embodiment, two second adhesive portions are symmetrically arranged on both sides of the first adhesive portion in the second direction; and two third adhesive portions are symmetrically arranged on both sides of the first adhesive portion in the first direction.

[0017] In one alternative embodiment, the first adhesive portion is provided with a clearance hole.

[0018] In one optional embodiment, the cell cover insulation structure is a wound cylindrical structure, which includes a plurality of the insulating films.

[0019] Secondly, this application provides a battery cell, including the battery cell cover insulation structure described in any of the above technical solutions. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 is a schematic diagram of the insulation film in the unfolded state in the insulation structure of the battery cell cover plate provided in the embodiment of this application;

[0022] Figure 2 is an enlarged structural diagram of point Q in Figure 1;

[0023] Figure 3 is a schematic diagram showing the dimensions and positions of some structures on the insulating film in the battery cell cover insulation structure provided in the embodiment of this application.

[0024] Figure 4 is a schematic diagram of the structure in which the insulating film covers the cover plate and the shell of the battery cell in the battery cell cover plate insulation structure provided in the embodiment of this application;

[0025] Figure 5 is a schematic diagram of the battery cell cover insulation structure provided in the embodiment of this application, which is wound into a cylindrical shape.

[0026] Reference numerals: 1-Insulating film; 10-Fold; 11-First adhesive part; 12-Second adhesive part; 121-Edge binding part; 13-Third adhesive part; 14-Notch; 15-Allowing hole; 2-Cut film; 20-Groove; 21-Sharp corner; 30-Cover plate; 40-Shell; 41-First surface; 42-Second surface; D1-First direction; D2-Second direction. Detailed Implementation

[0027] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0028] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0029] According to a first aspect of this application, a cell cover insulation structure is provided, which includes an insulating film 1.

[0030] The specific structure of the insulation structure of the cell cover 30 according to this embodiment will be described below.

[0031] In this embodiment, the insulating film 1 can be a flexible insulating tape. The insulating film 1 includes an insulating substrate layer and an insulating adhesive layer in its thickness direction, so that the insulating film 1 can be directly pasted on the surface of the cell cover plate 30 and the cell housing 40.

[0032] Specifically, as shown in Figures 1 and 4, creases 10 are formed on the insulating film 1 to divide the insulating film 1 into multiple regions, namely the first adhesive portion 11, the second adhesive portion 12, and the third adhesive portion 13. The dashed line in Figure 1 indicates the position of the crease 10. When the cell cover plate 30 is a rectangular structure, the crease 10 is a rectangular frame structure corresponding to the outer edge of the cell cover plate 30.

[0033] More specifically, the second adhesive portion 12 and the third adhesive portion 13 are alternately arranged around the circumference of the first adhesive portion 11. That is, the first adhesive portion 11 is located in the middle of the insulating film 1, and the second adhesive portion 12 and the third adhesive portion 13 are arranged around the circumference of the first adhesive portion 11. Multiple second adhesive portions 12 and third adhesive portions 13 are provided, arranged in the order of second adhesive portion 12, third adhesive portion 13, second adhesive portion 12, third adhesive portion 13 around the circumference of the first adhesive portion 11. The first adhesive portion 11 is attached to the surface of the cover plate 30 facing the outside of the battery cell, and the second adhesive portion 13 is bent along the crease 10. The second adhesive part 12 is partially attached to the first surface 41 of the housing 40, and the third adhesive part 13 is bent along the crease 10 and attached to the second surface 42 of the housing 40. This achieves insulation protection for the cover plate 30 and allows part of the insulating film 1 to be attached to the housing 40 of the battery cell. The connection between the cover plate 30 and the housing 40 can be effectively covered by the insulating film 1, and the insulation effect meets the requirements of the whole package, achieving the purpose of cost reduction and efficiency improvement. In addition, it increases the adhesive area and improves the adhesive strength, avoiding problems such as lifting and falling off, and ensuring the insulation effect and production efficiency of the battery cell.

[0034] The battery cell housing 40 is a rectangular housing 40, which gives the housing 40 four sides, two of which are two first surfaces 41 facing each other, and the other two are two second surfaces 42 facing each other. The second surfaces 42 are arranged adjacent to the first surfaces 41, and the area of ​​the first surfaces 41 is larger than the area of ​​the second surfaces 42.

[0035] Further, as shown in Figures 1 and 4, the second adhesive portion 12 has an edge-wrapping portion 121 formed at its end in the first direction D1. After the second adhesive portion 12 is attached to the first surface 41, it is bent so that the edge-wrapping portion 121 is attached to the second surface 42. In this way, the edge-wrapping portion 121 and the third adhesive portion 13 are jointly attached to the second surface 42, thereby achieving full circumferential coverage of the side of the housing 40, improving the adhesion strength of the insulating film 1, improving the insulation effect, and also improving the situation of wrinkles or lifting of the second adhesive portion 12 to a certain extent. Preferably, the edge-wrapping portion 121 is formed into a right-angled trapezoidal structure, so that the edge-wrapping portion 121 has a pointed end in the length direction of the second adhesive portion 12, so that the second adhesive portion 12 can be separated from the third adhesive portion 13, and also avoids defects such as skewed adhesion or wrinkles in the edge-wrapping portion 121.

[0036] In a preferred embodiment, as shown in FIG4, the third adhesive part 13 is attached to the upper layer of the edge wrapping part 121, thereby wrapping the edge wrapping part 121 inside the third adhesive part 13, preventing the edge wrapping part 121 from lifting up, and thus effectively preventing the insulating film 1 from falling off the battery cell.

[0037] Furthermore, in this embodiment, as shown in Figures 1 and 2, a notch 14 is provided between the edge-wrapping portion 121 and the third adhesive portion 13. This facilitates the application of the edge-wrapping portion 121 to the second surface 42 and improves the adaptability of the insulating film 1 to a certain extent, allowing the insulating film 1 to be applied to the relatively longer battery cell cover plate 30. Specifically, as shown in Figure 2, before the second adhesive portion 12 is bent, the length dimension of the notch 14 in the first direction D1 is H, 3mm≤H≤6mm. This avoids wrinkles in the second adhesive portion 12 and also ensures the insulation performance of the insulating film 1. The width dimension of the notch 14 in the second direction D2 is G, 0.2mm≤G≤0.3mm. This avoids wrinkles in the edge-wrapping portion 121 and also ensures the insulation performance of the insulating film 1. Importantly, it ensures the insulation effect at the corner position where the cover plate 30 and the shell 40 overlap after the insulating film 1 is applied.

[0038] It should be noted that the first direction D1 is perpendicular to the second direction D2. The first direction D1 is the length direction of the cover plate 30, and the second direction D2 is the width direction of the cover plate 30.

[0039] Preferably, as shown in Figures 1 and 2, before the insulating film 1 is bent along the crease 10, the dimension of the second adhesive part 12 in the second direction D2 is E, 2.5mm≤E≤10mm, thus ensuring the adhesive strength of the insulating film 1 and reducing costs; before the insulating film 1 is bent along the crease 10, the dimension of the third adhesive part 13 in the first direction D1 is F, 2.5mm≤F≤10mm, thus ensuring the adhesive strength of the insulating film 1 and avoiding material waste.

[0040] In a preferred embodiment, as shown in FIG4, E=F, so that after the insulating film 1 is pasted, the ends of the second adhesive part 12 and the third adhesive part 13 attached to the housing 40 away from the cover plate 30 are flush, thus reducing the risk of lifting to a certain extent and ensuring the insulation effect.

[0041] Further, in this embodiment, as shown in FIG3, two second adhesive portions 12 are symmetrically arranged on both sides of the first adhesive portion 11 in the second direction D2. The two second adhesive portions 12 have the same size in the second direction D2, which is E. The width of the cover plate 30 is B (i.e., the width of the first adhesive portion 11 in the second direction D2), in mm. The width of the insulating film 1 in the second direction D2 is D, in mm. E = (DB) / 2, so that the first adhesive portion 11 is located in the middle position of the insulating film 1 in the second direction D2. Two third adhesive portions 13 are symmetrically arranged on both sides of the first adhesive portion 11 in the first direction D1. The two third adhesive portions 13 have the same size in the first direction D1, which is F. The length of the cover plate 30 is A (i.e., the length of the first adhesive portion 11 in the first direction D1), in mm. The length of the insulating film 1 in the first direction D1 is C, in mm. F = (CA) / 2, so that the first adhesive portion 11 is located in the middle position of the insulating film 1 in the first direction D1, ensuring the adhesive reliability of the insulating film 1.

[0042] In this embodiment, as shown in Figures 1 to 4, the first adhesive part 11 is provided with a clearance hole 15. The clearance hole 15 is a through-hole structure that penetrates the insulating film 1, thus avoiding the pole, explosion-proof valve and / or liquid injection hole on the cover plate 30, allowing the pole, explosion-proof valve and / or liquid injection hole on the cover plate 30 to be exposed, meeting the usage requirements of the cover plate 30. The shape, number and position of the clearance hole 15 are set according to the structure of the cover plate 30.

[0043] In a preferred embodiment, as shown in FIG5, the insulation structure of the battery cell cover plate 30 is a cylindrical structure formed by rolling a whole sheet of cut film 2. The cylindrical structure includes multiple insulating films 1. When in use, the cut film 2 is unfolded from the cylindrical structure and cut to obtain the insulating film 1 attached to each cover plate 30.

[0044] Specifically, the third adhesive part 13 is disposed on both sides of the cut film 2 in the width direction. M-shaped grooves 20 are provided on both sides of the cut film 2 in the width direction, so that the cut film 2 has sharp corners 21 at both ends in the width direction. The line connecting the two sharp corners 21 in the width direction of the cut film 2 is the position for cutting the insulating film 1. It should be noted that the structure in the dashed box in Figure 5 is the insulating film 1 for attaching the battery cell.

[0045] The adhesion quality of insulating films 1 with different sizes of H, G, E and F after attaching to the battery cell was tested below. The specific results are shown in Table 1.

[0046] Table 1 Note: " / " in the table indicates that the insulation test and appearance inspection are qualified after the insulation film 1 is pasted.

[0047] As can be seen from the parameters in the table, in Examples 3, 4, 8, and 9, no peeling or wrinkling of the insulating film 1 was observed in the pasted battery cells, and the insulation test passed, meeting the usage requirements of the battery cells. The yield rate was improved, which to some extent proves that the parameter limits of 2.5mm≤E≤10mm, 2.5mm≤F≤10mm, 3mm≤H≤6mm, and 0.2mm≤G≤0.3mm can guarantee the insulation effect of the battery cells. However, in Examples 1 and 2, because the parameters E and F are too small, wrinkles easily appear on the edge 121, resulting in an increased proportion of peeling problems. In Examples 5 to 7, because the size of H is too small, the insulation performance of the insulating film 1 is reduced, and the failure rate of the insulation test is increased.

[0048] According to the battery cell cover insulation structure provided in this application, creases are formed on the insulating film to divide the insulating film into a first adhesive portion, a second adhesive portion, and a third adhesive portion. The first adhesive portion is attached to the cover plate, and the second adhesive portion is bent along the creases so that a portion of the second adhesive portion is attached to the first surface of the housing. The third adhesive portion is bent along the creases so that it is attached to the second surface of the housing. This achieves insulation protection for the cover plate and allows a portion of the insulating film to adhere to the battery cell housing, ensuring that the connection between the cover plate and the housing is effectively covered. The insulation effect meets the overall packaging requirements, achieving the goal of cost reduction and efficiency improvement. In addition, the adhesive area is increased, the adhesive strength is improved, and problems such as lifting and falling off are avoided, ensuring the insulation effect of the battery cell and production efficiency.

[0049] According to this application, a battery cell includes the battery cell cover insulation structure as described above. The insulation film has a large coverage area and high bonding strength, and the insulation effect meets the requirements of the entire package, reducing costs and ensuring the insulation effect and production efficiency of the battery cell.

[0050] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents. Industrial applicability

[0051] The cell cover insulation structure of this application has creases formed on the insulating film to divide it into a first adhesive portion, a second adhesive portion, and a third adhesive portion. The first adhesive portion is attached to the cover plate. The second adhesive portion is bent along the creases so that a portion of the second adhesive portion is attached to the first surface of the housing. The third adhesive portion is bent along the creases so that it is attached to the second surface of the housing. This achieves insulation protection for the cover plate and allows a portion of the insulating film to adhere to the cell housing. The connection between the cover plate and the housing can be effectively covered, and the insulation effect meets the overall packaging requirements, achieving the goal of cost reduction and efficiency improvement. In addition, it increases the adhesive area and improves the adhesive strength, avoiding problems such as lifting and falling off, and ensuring the insulation effect of the cell and production efficiency.

Claims

1. An electrical cell cover plate insulation structure, characterized by, Includes an insulating film, on which creases are formed to divide the insulating film into a first adhesive portion, a second adhesive portion and a third adhesive portion; The second adhesive portion and the third adhesive portion are alternately arranged around the circumference of the first adhesive portion; the first adhesive portion is attached to the cover plate, the second adhesive portion is bent along the crease so that a portion of the second adhesive portion is attached to the first surface of the housing, and the third adhesive portion is bent along the crease so that it is attached to the second surface of the housing.

2. The cell cover plate insulation structure of claim 1, wherein, The second adhesive part has a edging portion at its end in the first direction. After the second adhesive part is attached to the first surface, the second adhesive part is bent so that the edging portion is attached to the second surface.

3. The cell cover plate insulation structure of claim 2, wherein, The third adhesive part is attached to the upper layer of the edge banding part.

4. The cell cover plate insulation structure of claim 2, wherein, A notch is provided between the edge binding part and the third adhesive part; before the second adhesive part is bent, the length dimension of the notch in the first direction is H, 3mm≤H≤6mm, and the width dimension of the notch in the second direction is G, 0.2mm≤G≤0.3mm.

5. The cell cover plate insulation structure of claim 1, wherein, Before bending along the crease, the second adhesive part has a dimension of E in the second direction, 2.5mm≤E≤10mm, and the third adhesive part has a dimension of F in the first direction, 2.5mm≤F≤10mm.

6. The cell cover plate insulation structure of claim 5, wherein, E = F.

7. The cell cover plate insulation structure of claim 1, wherein, Two second adhesive portions are symmetrically arranged on both sides of the first adhesive portion in the second direction; two third adhesive portions are symmetrically arranged on both sides of the first adhesive portion in the first direction.

8. The cell cover plate insulation structure of claim 1, wherein, The first adhesive part has a clearance hole.

9. The cell cover plate insulation structure of claim 1, wherein, The cell cover plate insulation structure is a wound cylindrical structure, which includes multiple insulating films.

10. An electric cell characterized by Including the cell cover insulation structure as described in any one of claims 1 to 9.

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