Battery cell insulating film

Abstract

A battery cell insulating film, comprising an insulating film body formed by a bottom surface covering region, end surface covering regions, first side surface covering regions, and second side surface covering regions, wherein both sides of the bottom surface covering region are connected to the first side surface covering regions, both sides of each end surface covering region are connected to the second side surface covering regions, and the end surface covering regions are connected to both sides of the bottom surface covering region. The total area covered by the first side surface covering regions and the second side surface covering regions after folding is S1, and the overlapping area between the first side surface covering regions and the second side surface covering regions after folding is S, satisfying: 5 mm2≤S≤(0.6×S1) mm2. This ensures that the insulating film body provides sufficient overlapping area on the side surfaces of an electrode assembly, such that the side surfaces of the electrode assembly after being covered with the insulating film body have relatively good cushioning performance, thereby reducing particle shedding caused by vibration and lowering the risks of corroding a battery cell casing and causing damage to the internal insulating environment, improving the protective performance.

Description

Battery cell insulation film

[0001] Cross-reference to related applications

[0002] This application claims priority to the Chinese patent application No. CN202411259885.7, filed on September 10, 2024, entitled "Battery cell insulation film", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application belongs to the technical field of batteries, and in particular relates to a battery cell insulation film. BACKGROUND

[0004] In the production process of lithium batteries, a layer of insulation film with soft texture and flexibility is usually coated on the pole group before it is put into the shell. On the one hand, the pole group is coated to ensure that it is in an insulated state, which plays an insulating role and avoids internal short circuit failure caused by contact with the aluminum shell. On the other hand, it prevents the hard aluminum shell from causing damage to the pole group, thereby protecting the pole group.

[0005] However, in the process of using the battery, vibration caused by external factors is a common situation. During the vibration process of the battery, vibration waves are transmitted to the inside of the battery. The insulation film itself has a certain degree of buffering capacity and can reduce a part of the vibration waves transmitted to the pole group. However, on the side of the pole group, the insulation film is spliced through different areas to achieve coverage, and there are splicing gaps between them, which have weak buffering performance, resulting in the situation that the powder particles fall off due to vibration on the side of the pole group, thereby causing the fallen powder particles to corrode the shell and destroy the internal insulation environment, leading to the battery cannot be used normally and reducing the service life of the battery.

[0006] SUMMARY

[0007] Therefore, the purpose of the present application is to provide a battery cell insulation film with good buffering performance and excellent protection.

[0008] The present application provides a battery cell insulation film, which is coated on the outside of the pole group and accommodated in the battery cell shell, characterized in that the battery cell insulation film comprises an insulation film body, the insulation film body comprises a bottom surface coating area, an end surface coating area, a first side surface coating area and a second side surface coating area, the bottom surface coating area is connected with the first side surface coating area on both sides along a first direction, the end surface coating area is connected with the second side surface coating area on both sides along the first direction, and the end surface coating area is connected to both sides of the bottom surface coating area along a second direction.

[0009] The total area covered by the first side surface coating area and the second side surface coating area after folding is S1, the overlapping area of the first side surface coating area and the second side surface coating area after folding is S, and S satisfies 5mm2 ≤S≤(0.6×S1)mm 2 .

[0010] Beneficial effects: the insulating film of the battery cell is limited by S and S1, which ensures that the side surface of the pole group has enough area of the insulating film body, so that the pole group after being wrapped with the insulating film body has good buffering performance, reduces the situation of powder particles falling off due to vibration, reduces the risk of corrosion of the battery shell and damage to the internal insulation environment, improves the protection of the side surface of the pole group, and prolongs the service life of the battery.

[0011] In an optional embodiment, a first crease and a second crease are arranged between each of the second side surface wrapping areas and the end surface wrapping area, and the two second creases on both sides of the end surface wrapping area along the first direction are located inside the two first creases on both sides of the end surface wrapping area along the first direction.

[0012] In an optional embodiment, the battery shell includes a shell body, the shell body includes a shell side plate, the length of the shell body is A, the first thickness of the shell side plate is B1, the first crease is arranged between the end surface wrapping area and the second side surface wrapping area connected to both sides of the end surface wrapping area along the first direction, the first distance between the two first creases is L1, and satisfies (A-B1×2-5)mm≤L1≤(A-B1×2-0.1)mm.

[0013] In an optional embodiment, the battery shell further includes a shell bottom plate, a cover plate body, and a lower insulating piece connected to the inside of the cover plate body, the second thickness of the lower insulating piece is B2, the third thickness of the cover plate body is B3, the height of the shell body is C, and the fourth thickness of the shell bottom plate is B4.

[0014] A third crease is arranged between each of the end surface wrapping area and the bottom surface wrapping area, the second distance between the third crease and the boundary on the side of the end surface wrapping area away from the bottom surface wrapping area is L2, and satisfies (C-B4-B3-B2+3)mm≤L2≤(C-B4-B3-1)mm.

[0015] In an optional embodiment, each of the third creases is provided with a bending groove between the end surface wrapping area and the bottom surface wrapping area on both sides of the first direction, and the bending groove extends along the first direction.

[0016] The groove width of the bending groove is W, and satisfies 0.1mm≤W≤2mm.

[0017] And / or, a size of the bending groove extending along a direction close to the third crease is H, and satisfies 1mm≤H≤5mm.

[0018] In an optional embodiment, a third distance between an end of the first crease away from the bottom surface cladding region and an edge of the end surface cladding region away from the bottom surface cladding region along the second direction is L3, and satisfies 0.5mm≤L3≤5mm, and a fourth distance between an end of the first crease close to the bottom surface cladding region and an edge of the end surface cladding region close to the bottom surface cladding region along the second direction is L4, and satisfies 0.5mm≤L4≤5mm.

[0019] And / or, a fifth distance between an end of the second crease away from the bottom surface cladding region and an edge of the end surface cladding region away from the bottom surface cladding region along the second direction is L5, and satisfies 0.5mm≤L5≤5mm, and a sixth distance between an end of the second crease close to the bottom surface cladding region and an edge of the end surface cladding region close to the bottom surface cladding region along the second direction is L6, and satisfies 0.5mm≤L6≤5mm.

[0020] In an optional embodiment, a seventh distance between the first crease and the second crease on the same side of the end surface cladding region along the first direction is L7, and satisfies 0mm≤L7≤8mm.

[0021] In an optional embodiment, a thickness of the insulating film body is T, a depth of the first crease is T1, and satisfies 1 / 3×T≤T1≤1 / 2×T.

[0022] And / or, a depth of the second crease is T2, and satisfies 1 / 3×T≤T2≤1 / 2×T.

[0023] In an optional embodiment, an included angle between an edge of the second side surface cladding region close to the first side surface cladding region and the first crease is θ1, and satisfies 15°≤θ1≤90°.

[0024] And / or, a fourth crease is arranged between each of the first side surface cladding region and the bottom surface cladding region, and an included angle between an edge of the first side surface cladding region close to the second side surface cladding region and the fourth crease is θ2, and satisfies 15°≤θ2≤90°.

[0025] In an optional embodiment, a plurality of spaced-through structures are further arranged on the bottom surface cladding region, and a spacing between each of two adjacent spaced-through structures along the first direction is N, and satisfies 5mm≤N≤30mm. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the drawings required to be used in the description of the specific embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0027] Fig. 1 is a front view of the electric core insulation film in an unfolded state according to the present application;

[0028] Fig. 2 is an enlarged view of part I in Fig. 1;

[0029] Fig. 3 is a display diagram of the overlapping area of the first side covering area and the second side covering area in the electric core insulation film according to the present application;

[0030] Fig. 4 is a display diagram of the covering area of the first side covering area and the second side covering area after folding in the electric core insulation film according to the present application;

[0031] Fig. 5 is a top view of the electric core insulation film in an unfolded state according to the present application;

[0032] Fig. 6 is a structural sectional view of the shell of the battery shell for accommodating the pole group in the electric core insulation film according to the present application;

[0033] Fig. 7 is a partial structural enlarged view of the combination of the cover plate body and the lower insulation piece of the battery shell for accommodating the pole group in the electric core insulation film according to the present application.

[0034] Reference numerals: 10 - insulation film body; 101 - bottom covering area; 102 - end surface covering area; 103 - first side covering area; 104 - second side covering area; 105 - first crease; 106 - second crease; 107 - third crease; 108 - fourth crease; 109 - bending groove; 110 - through structure; 20 - shell; 30 - shell side plate; 40 - shell bottom plate; 50 - cover plate body; 60 - lower insulation piece. DETAILED DESCRIPTION

[0035] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0036] The disclosure below provides many different embodiments or examples for implementing different structures of the application. For the purpose of simplification of the present disclosure, certain examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, reference numerals can be repeated in different examples in the present application. Such repetition is for the purpose of simplification and clarity and does not indicate a relationship between the various embodiments and / or arrangements discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art can realize the applicability of other processes and / or the use of other materials.

[0037] In the production process of lithium battery, a layer of soft and flexible insulating film is usually coated on the pole group before entering the shell. On the one hand, the pole group is coated to ensure that the pole group is in an insulating state, plays an insulating role, avoids internal short circuit failure caused by contact with aluminum shell, and on the other hand, prevents hard aluminum shell from causing damage to the pole group, and plays a protective role for the pole group.

[0038] However, in the process of use, the vibration caused by external factors is a common situation. In the process of vibration, the vibration wave will be transmitted to the inside of the battery. The insulating film itself has a certain degree of buffering capacity, which can reduce a part of the vibration wave transmitted to the pole group. However, on the side of the pole group, the insulating film is spliced through different areas to achieve coverage, and there are splicing gaps between each other, which has weak buffering performance, resulting in the situation that the powder particles fall off due to vibration on the side of the pole group, thereby causing the fallen powder particles to corrode the shell, destroy the internal insulation environment, cause the battery to be unable to be used normally, reduce the service life of the battery.

[0039] Therefore, in order to make the side of the pole group coated with the insulating film body have good buffering performance, reduce the situation that the powder particles fall off due to vibration, reduce the risk of corrosion to the battery shell and damage to the internal insulation environment, improve the protection, and prolong the service life of the battery, the present embodiment provides a battery core insulating film. The battery core insulating film is coated on the outside of the pole group and accommodated in the battery core shell.

[0040] Embodiment one

[0041] As shown in FIGS. 1-7, the cell insulation film includes an insulation film body 10, which includes a bottom surface covering area 101, an end surface covering area 102, a first side surface covering area 103, and a second side surface covering area 104. The first side surface covering area 103 is connected to both sides of the bottom surface covering area 101 along a first direction. The second side surface covering area 104 is connected to both sides of the end surface covering area 102 along the first direction. The end surface covering area 102 is connected to both sides of the bottom surface covering area 101 along a second direction. The total area covered by the first side surface covering area 103 and the second side surface covering area 104 after folding is S1. The overlapping area of the first side surface covering area 103 and the second side surface covering area 104 after folding is S, and satisfies 5mm 2 ≤S≤(0.6×S1)mm 2 .

[0042] By the insulation film body 10 composed of the bottom surface covering area 101, the end surface covering area 102, the first side surface covering area 103, and the second side surface covering area 104, wherein the first side surface covering area 103 is connected to both sides of the bottom surface covering area 101 along a first direction. The second side surface covering area 104 is connected to both sides of the end surface covering area 102 along the first direction. The end surface covering area 102 is connected to both sides of the bottom surface covering area 101 along a second direction. Thus, the bottom surface of the pole group is covered by the bottom surface covering area 101, the end surface of the pole group is covered by the end surface covering area 102, and the side surface of the pole group is covered by the first side surface covering area 103 and the second side surface covering area 104 together. The total area covered by the first side surface covering area 103 and the second side surface covering area 104 after folding is S1. The overlapping area of the first side surface covering area 103 and the second side surface covering area 104 after folding is S. Both are limited to satisfy 5mm 2 ≤S≤(0.6×S1)mm 2 , which ensures that the overlapping area of the first side surface covering area 103 and the second side surface covering area 104 after folding is moderate on the side surface of the pole group, so that the side surface of the pole group after being covered by the insulation film body 10 has good cushioning, reduces the situation of powder particles falling off due to vibration, reduces the risk of corrosion of the cell shell and damage to the internal insulation environment, improves the protection of the side surface of the pole group, and prolongs the service life of the battery.

[0043] In order to verify the rationality of the overlapping area S of the first side surface covering area 103 and the second side surface covering area 104 after folding, as shown in Table 1, thirteen groups of examples and three groups of comparative examples are provided to illustrate. Through the oscillation test of the cell, the working condition environment under the vibration condition is simulated. After standing for a period of time, whether the corrosion of the cell shell and the damage to the internal insulation environment leading to the conduction of the battery shell are observed.

[0044] Table 1

[0045] In Example 1, the total area S1 covered by the first side covering area 103 and the second side covering area 104 after folding is set to 8400 mm. 2 The overlap area S after folding the first side covering area 103 and the second side covering area 104 is set to be 5mm. 2 To make it meet the 5mm requirement 2 ≤S≤(0.6×S1)mm 2 Within the set range, after a vibration test and three days of storage, no corrosion was found on the battery casing, nor was there any electrical conductivity caused by damage to the internal insulation environment.

[0046] In Example 2, the total area S1 covered by the first side covering area 103 and the second side covering area 104 after folding is set to 8400 mm. 2 The overlap area S after folding the first side covering area 103 and the second side covering area 104 is set to be 500 mm. 2 To make it meet the 5mm requirement 2 ≤S≤(0.6×S1)mm 2 Within the set range, after a vibration test and three days of storage, no corrosion was found on the battery casing, nor was there any electrical conductivity caused by damage to the internal insulation environment.

[0047] In embodiment 3, the total area S1 covered by the first side covering area 103 and the second side covering area 104 after folding is set to 8400 mm. 2 The overlap area S after folding the first side covering area 103 and the second side covering area 104 is set to be 1000 mm. 2 To make it meet the 5mm requirement 2 ≤S≤(0.6×S1)mm 2 Within the set range, after a vibration test and three days of storage, no corrosion was found on the battery casing, nor was there any electrical conductivity caused by damage to the internal insulation environment.

[0048] In Example 4, the total area S1 covered by the first side covering area 103 and the second side covering area 104 after folding is set to 8400 mm. 2 The overlap area S after folding the first side covering area 103 and the second side covering area 104 is set to be 2000 mm. 2 To make it meet the 5mm requirement 2 ≤S≤(0.6×S1)mm 2 Within the set range, after a vibration test and three days of storage, no corrosion was found on the battery casing, nor was there any electrical conductivity caused by damage to the internal insulation environment.

[0049] In Example 5, the total area S1 = 8400 mm covered after folding of the first side covering area 103 and the second side covering area 104 was set 2 , the overlapping area S = 3000 mm after folding of the first side covering area 103 and the second side covering area 104 was set 2 so as to satisfy 5 mm 2 ≤ S ≤ (0.6 x S1) mm 2 After the shock test, no corrosion of the battery case and the case of the battery case being conductive due to the internal insulation environment being destroyed were found after being left for three days.

[0050] In Example 6, the total area S1 = 8400 mm covered after folding of the first side covering area 103 and the second side covering area 104 was set 2 , the overlapping area S = 4000 mm after folding of the first side covering area 103 and the second side covering area 104 was set 2 so as to satisfy 5 mm 2 ≤ S ≤ (0.6 x S1) mm 2 After the shock test, no corrosion of the battery case and the case of the battery case being conductive due to the internal insulation environment being destroyed were found after being left for three days.

[0051] In Example 7, the total area S1 = 8400 mm covered after folding of the first side covering area 103 and the second side covering area 104 was set 2 , the overlapping area S = 5040 mm after folding of the first side covering area 103 and the second side covering area 104 was set 2 so as to satisfy 5 mm 2 ≤ S ≤ (0.6 x S1) mm 2 After the shock test, no corrosion of the battery case and the case of the battery case being conductive due to the internal insulation environment being destroyed were found after being left for three days.

[0052] In Example 8, the total area S1 = 800 mm covered after folding of the first side covering area 103 and the second side covering area 104 was set 2 , the overlapping area S = 30 mm after folding of the first side covering area 103 and the second side covering area 104 was set 2 so as to satisfy 5 mm 2 ≤ S ≤ (0.6 x S1) mm 2 After the shock test, no corrosion of the battery case and the case of the battery case being conductive due to the internal insulation environment being destroyed were found after being left for three days.

[0053] In Example 9, the total area S1 of the first side covering area 103 and the second side covering area 104 after folding is set to 3000 mm 2 The overlapping area S of the first side covering area 103 and the second side covering area 104 after folding is set to 40 mm 2 to satisfy 5 mm 2 ≤ S ≤ (0.6 x S1) mm 2 After the shock test, no corrosion of the battery case and the case of the battery case being conductive due to the internal insulation environment being destroyed were found after being placed for three days.

[0054] In Example 10, the total area S1 of the first side covering area 103 and the second side covering area 104 after folding is set to 5000 mm 2 The overlapping area S of the first side covering area 103 and the second side covering area 104 after folding is set to 60 mm 2 to satisfy 5 mm 2 ≤ S ≤ (0.6 x S1) mm 2 After the shock test, no corrosion of the battery case and the case of the battery case being conductive due to the internal insulation environment being destroyed were found after being placed for three days.

[0055] In Example 11, the total area S1 of the first side covering area 103 and the second side covering area 104 after folding is set to 12000 mm 2 The overlapping area S of the first side covering area 103 and the second side covering area 104 after folding is set to 80 mm 2 to satisfy 5 mm 2 ≤ S ≤ (0.6 x S1) mm 2 After the shock test, no corrosion of the battery case and the case of the battery case being conductive due to the internal insulation environment being destroyed were found after being placed for three days.

[0056] In Example 12, the total area S1 of the first side covering area 103 and the second side covering area 104 after folding is set to 2000 mm 2 The overlapping area S of the first side covering area 103 and the second side covering area 104 after folding is set to 120 mm 2 to satisfy 5 mm 2 ≤ S ≤ (0.6 x S1) mm 2 After the shock test, no corrosion of the battery case and the case of the battery case being conductive due to the internal insulation environment being destroyed were found after being placed for three days.

[0057] In Example 13, the total area S1 covered by the first side covering area 103 and the second side covering area 104 after folding is set to 30000 mm 2 The overlapping area S of the first side covering area 103 and the second side covering area 104 after folding is set to 150 mm 2 to satisfy 5 mm 2 ≤ S ≤ (0.6 × S1) mm 2 After the shock test, no corrosion of the battery shell and no conduction of the battery shell due to damage to the internal insulation environment were found after three days.

[0058] As can be seen from Examples 1 to 13, when the size of the total area S1 covered by the first side covering area 103 and the second side covering area 104 after folding is set, and the overlapping area S of the first side covering area 103 and the second side covering area 104 after folding satisfies the set range of 5 mm 2 ≤ S ≤ (0.6 × S1) mm 2 , the shock test can be successfully passed, and the risk of corrosion of the battery shell and damage to the internal insulation environment due to vibration is reduced, the protection is improved, and the service life of the battery is prolonged.

[0059] In Comparative Example 1, the total area S1 covered by the first side covering area 103 and the second side covering area 104 after folding is set to 8400 mm 2 The overlapping area S of the first side covering area 103 and the second side covering area 104 after folding is set to -10 mm 2 , which does not satisfy the set range of 5 mm 2 ≤ S ≤ (0.6 × S1) mm 2 At this time, the first side covering area 103 does not have an overlapping area with the second side covering area 104, so that a part of the side of the pole group is exposed. After the shock test, it was found that the battery shell was corroded and the battery shell was conductive due to damage to the internal insulation environment after three days.

[0060] In Comparative Example 2, the total area S1 covered by the first side covering area 103 and the second side covering area 104 after folding is set to 8400 mm 2 The overlapping area S of the first side covering area 103 and the second side covering area 104 after folding is set to 3 mm 2 , which does not satisfy the set range of 5 mm 2 ≤ S ≤ (0.6 × S1) mm 2When the overlapping area S of the first side covering area 103 and the second side covering area 104 is less than the minimum value of the set range, after the vibration test, it is found that the battery shell is corroded and the internal insulation environment is destroyed, and the battery shell is conductive.

[0061] In the comparative example 3, the total area S1 of the first side covering area 103 and the second side covering area 104 covered after folding is set to 8400mm 2 The overlapping area S of the first side covering area 103 and the second side covering area 104 after folding is set to 5880mm 2 , which does not meet the set range of 5mm 2 ≤S≤(0.6×S1)mm 2 , at this time the overlapping area of the first side covering area 103 and the second side covering area 104 is greater than the maximum value of the set range, after the vibration test, it is found that the battery shell is not corroded and the internal insulation environment is destroyed, and the battery shell is not conductive, but the covering area is larger, which leads to more use of the insulating film of the battery cell and higher cost.

[0062] As can be seen from the comparative examples 1 to 3, when the total area S1 of the first side covering area 103 and the second side covering area 104 covered after folding is set, when the overlapping area S of the first side covering area 103 and the second side covering area 104 after folding is less than the minimum value of the set range, after the vibration test, it is found that the battery shell is corroded and the internal insulation environment is destroyed, and the battery shell is conductive; when the overlapping area S of the first side covering area 103 and the second side covering area 104 after folding is greater than the maximum value of the set range, after the vibration test, although the battery shell is not corroded and the internal insulation environment is not destroyed, and the battery shell is not conductive, but the covering area is larger, which leads to more use of the insulating film of the battery cell and higher cost.

[0063] Optionally, as shown in FIG. 1, the first crease 105 and the second crease 106 are arranged between each second side covering area 104 and the end face covering area 102, and the two second creases 106 on both sides of the end face covering area 102 along the first direction are located inside the two first creases 105 on both sides of the end face covering area 102 along the first direction. Since the shell 20 of the battery shell is provided with a rounded corner, by arranging the first crease 105 and the second crease 106 between each second side covering area 104 and the end face covering area 102, a bevel structure can be formed between the second side covering area 104 and the end face covering area 102 after the second side covering area 104 is bent, avoiding the rounded corner in the shell 20, thereby facilitating the smooth entry of the polar group after covering the insulating film of the battery cell into the shell.

[0064] Optionally, as shown in FIG. 1, FIG. 6, the battery cell shell comprises a shell 20, the shell 20 comprises a shell side plate, the length dimension of the shell 20 is A, the first thickness dimension of the shell side plate 30 is B1, the first crease 105 is arranged between the end face covering area 102 and the second side covering area 104 connected to the two sides of the end face covering area 102 along the first direction, the first spacing dimension between the two first creases 105 is L1, and satisfies (A-B1*2-5)mm≤L1≤(A-B1*2-0.1)mm. By limiting the first spacing dimension L1 between the two first creases 105 to satisfy the range of (A-B1*2-5)mm≤L1≤(A-B1*2-0.1)mm, the length of the end face covering area 102 is ensured to be less than the length dimension of the internal space of the shell 20, so that the pole group after covering the battery cell insulating film can be smoothly put into the shell.

[0065] Optionally, as shown in FIG. 1, FIG. 6, FIG. 7, the battery cell shell further comprises a shell bottom plate, a cover plate body 50 and a lower insulating piece 60 connected to the inner side of the cover plate body 50, the second thickness dimension of the lower insulating piece 60 is B2, the third thickness dimension of the cover plate body 50 is B3, the height dimension of the shell 20 is C, and the fourth thickness dimension of the shell bottom plate 40 is B4; the third crease 107 is arranged between each end face covering area 102 and the bottom surface covering area 101, the second spacing dimension between the third crease 107 and the boundary of the side of the end face covering area 102 away from the bottom surface covering area 101 is L2, and satisfies (C-B4-B3-B2+3)mm≤L2≤(C-B4-B3-1)mm.

[0066] By limiting the second spacing dimension L2 between the third crease 107 and the boundary of the side of the end face covering area 102 away from the bottom surface covering area 101 to satisfy the range of (C-B4-B3-B2+3)mm≤L2≤(C-B4-B3-1)mm, the height dimension of the end face covering area 102 is ensured to be less than the height dimension of the internal space of the shell 20, so that the pole group after covering the battery cell insulating film is put into the shell 20, and installation space is reserved for the cover plate body 50 and the lower insulating piece 60, so that interference does not occur during assembly.

[0067] Optionally, as shown in FIG. 1, FIG. 2, the third crease 107 is provided with a bending groove 109 between the end face covering area 102 and the bottom surface covering area 101 on both sides along the first direction, the bending groove 109 extends along the first direction, the groove width dimension of the bending groove 109 is W, and satisfies 0.1mm≤W≤2mm.

[0068] By setting the bending groove 109 between the end face covering area 102 and the bottom surface covering area 101 on both sides of each third crease 107 along the first direction, and limiting the groove width size W of the bending groove 109 to satisfy 0.1mm≤W≤2mm, the end face covering area 102 is conveniently bent.

[0069] In the embodiment, the groove width size W of the bending groove 109 can be any value between 0.1mm and 2mm, or a range between any two values, such as 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, etc.

[0070] Further, as shown in FIG. 2, the size H of the bending groove 109 extending along the direction close to the third crease 107 satisfies 1mm≤H≤5mm. By limiting the size H of the bending groove 109 extending along the direction close to the third crease 107 to satisfy 1mm≤H≤5mm, on the one hand, it ensures that the bending groove 109 has sufficient depth, which can reduce the resistance to the end face covering area 102 during bending, and on the other hand, it avoids the bending groove 109 being too deep, which causes the pole piece to be exposed and affects the insulation performance.

[0071] In the embodiment, the size H of the bending groove 109 extending along the direction close to the third crease 107 can be any value between 1mm and 5mm, or a range between any two values, such as 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0072] Alternatively, as shown in FIG. 1, the third distance size L3 between the end of the first crease 105 away from the bottom surface covering area 101 and the edge of the end face covering area 102 away from the bottom surface covering area 101 along the second direction satisfies 0.5mm≤L3≤5mm, and the fourth distance size L4 between the end of the first crease 105 close to the bottom surface covering area 101 and the edge of the end face covering area 102 close to the bottom surface covering area 101 along the second direction satisfies 0.5mm≤L4≤5mm. By limiting the third distance size L3 between the end of the first crease 105 away from the bottom surface covering area 101 and the edge of the end face covering area 102 away from the bottom surface covering area 101 along the second direction, and the fourth distance size L4 between the end of the first crease 105 close to the bottom surface covering area 101 and the edge of the end face covering area 102 close to the bottom surface covering area 101 along the second direction to satisfy 0.5mm≤L3≤5mm and 0.5mm≤L4≤5mm respectively, the two ends of the first crease 105 are spaced apart from the edges on both sides of the end face covering area 102 along the second direction, avoiding the first crease 105 being too long, so that the edges on both sides of the end face covering area 102 along the second direction have sufficient thickness, ensuring the structural strength of the end face covering area 102.

[0073] In the embodiment, the third distance L3 between the end of the first crease 105 away from the bottom surface covering area 101 and the edge of the end surface covering area 102 away from the bottom surface covering area 101 can be any value between 0.5mm and 5mm, or a range between any two values, such as 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0074] In the embodiment, the fourth distance L4 between the end of the first crease 105 close to the bottom surface covering area 101 and the edge of the end surface covering area 102 close to the bottom surface covering area 101 can be any value between 0.5mm and 5mm, or a range between any two values, such as 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0075] In addition, the third distance L3 between the end of the first crease 105 away from the bottom surface covering area 101 and the edge of the end surface covering area 102 away from the bottom surface covering area 101 can be the same as the fourth distance L4 between the end of the first crease 105 close to the bottom surface covering area 101 and the edge of the end surface covering area 102 close to the bottom surface covering area 101, or can be different. In the embodiment, L3=L4.

[0076] Alternatively, as shown in FIG. 1, the fifth distance L5 between the end of the second crease 106 away from the bottom surface covering area 101 and the edge of the end surface covering area 102 away from the bottom surface covering area 101 along the second direction is 0.5mm≤L5≤5mm, and the sixth distance L6 between the end of the second crease 106 close to the bottom surface covering area 101 and the edge of the end surface covering area 102 close to the bottom surface covering area 101 along the second direction is 0.5mm≤L6≤5mm. By limiting the fifth distance L5 between the end of the second crease 106 away from the bottom surface covering area 101 and the edge of the end surface covering area 102 away from the bottom surface covering area 101 and the sixth distance L6 between the end of the second crease 106 close to the bottom surface covering area 101 and the edge of the end surface covering area 102 close to the bottom surface covering area 101, both of which satisfy the range of 0.5mm≤L5≤5mm and 0.5mm≤L6≤5mm, respectively, so that the two ends of the second crease 106 are spaced apart from the edges of the end surface covering area 102 along the second direction, avoiding the second crease 106 being too long, so that the edges of the end surface covering area 102 along the second direction have sufficient thickness, ensuring the structural strength of the end surface covering area 102.

[0077] In the embodiment, the fifth distance dimension L5 between the end of the second crease 106 away from the bottom surface covering area 101 and the edge of the end surface covering area 102 away from the bottom surface covering area 101 can be any value between 0.5mm and 5mm or a range between any two values, for example, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0078] In the embodiment, the fifth distance dimension L5 between the end of the second crease 106 away from the bottom surface covering area 101 and the edge of the end surface covering area 102 away from the bottom surface covering area 101 can be any value between 0.5mm and 5mm or a range between any two values, for example, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0079] In addition, the fifth distance dimension L5 between the end of the second crease 106 away from the bottom surface covering area 101 and the edge of the end surface covering area 102 away from the bottom surface covering area 101 and the sixth distance dimension L6 between the end of the second crease 106 close to the bottom surface covering area 101 and the edge of the end surface covering area 102 close to the bottom surface covering area 101 can be the same value or different values. In the embodiment, L5=L6.

[0080] Optionally, as shown in FIG. 1, the seventh distance dimension between the first crease 105 and the second crease 106 on the same side of the end surface covering area 102 in the first direction is L7, and satisfies 0mm≤L7≤8mm. By limiting the seventh distance dimension L7 between the first crease 105 and the second crease 106 to satisfy 0mm≤L7≤8mm, it is ensured that the cross-sectional structure formed between the second side surface covering area 104 and the end surface covering area 102 after folding can avoid the round corner inside the shell 20, thereby facilitating the smooth entry of the pole group after covering the insulating film of the battery cell into the shell.

[0081] In the embodiment, the seventh distance dimension L7 between the first crease 105 and the second crease 106 on one side of the end surface covering area 102 in the first direction can be any value between 0mm and 8mm or a range between any two values, for example, 0mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, etc.

[0082] Optionally, as shown in FIG. 1 and FIG. 5, the thickness dimension of the insulating film body 10 is T, the depth dimension of the first crease 105 is T1, and 1 / 3×T≤T1≤1 / 2×T is satisfied. By limiting the depth dimension T1 of the first crease 105 to satisfy 1 / 3×T≤T1≤1 / 2×T, it is ensured that there is sufficient thickness after the first crease 105 is formed on the insulating film body 10, thereby ensuring the insulation performance of the pole group.

[0083] Optionally, as shown in FIG. 1 and FIG. 5, the depth dimension of the second crease 106 is T2, and 1 / 3×T≤T2≤1 / 2×T is satisfied. By limiting the depth dimension T2 of the second crease 106 to satisfy 1 / 3×T≤T2≤1 / 2×T, it is ensured that there is sufficient thickness after the second crease 106 is formed on the insulating film body 10, thereby ensuring the insulation performance of the pole group.

[0084] In the embodiment, T1=T2.

[0085] Optionally, as shown in FIG. 1, the included angle between the edge of the second side covering area 104 close to the first side covering area 103 and the first crease 105 is θ1, and 15°≤θ1≤90° is satisfied. By making the edge of the first side covering area 103 close to the second side covering area 104 and the first crease 105 exist an included angle θ1, and making the included angle θ1 satisfy 15°≤θ1≤90°, thereby facilitating the bending of the first side covering area 103.

[0086] In the embodiment, the included angle θ1 between the edge of the first side covering area 103 close to the second side covering area 104 and the first crease 105 can be any value between 15° and 90° or a range between any two values, for example, 15°, 30°, 45°, 90°, etc.

[0087] Optionally, as shown in FIG. 1, the fourth crease 108 is arranged between each first side covering area 103 and the bottom covering area 101, and the included angle between the edge of the second side covering area 104 close to the first side covering area 103 and the fourth crease 108 is θ2, and 15°≤θ2≤90° is satisfied. By making the edge of the second side covering area 104 close to the first side covering area 103 and the fourth crease 108 exist an included angle θ2, and making the included angle θ2 satisfy 15°≤θ2≤90°, thereby facilitating the bending of the second side covering area 104.

[0088] In the embodiment, the included angle θ2 between the edge of the second side covering area 104 close to the first side covering area 103 and the fourth crease 108 can be any value between 15° and 90° or a range between any two values, for example, 15°, 30°, 45°, 90°, etc.

[0089] Optionally, as shown in FIG. 1, the bottom covering area 101 is further provided with a plurality of spaced-through structures 110, and the spacing dimension between each adjacent two spaced-through structures 110 in the first direction is N, and satisfies 5mm≤N≤30mm. By providing a plurality of spaced-through structures 110 on the bottom covering area 101, and making the spacing dimension N between each adjacent two spaced-through structures 110 satisfy 5mm≤N≤30mm, so that when the electrolyte is injected into the shell 20, the electrolyte can be infiltrated into the pole group through the spaced-through structures 110.

[0090] In the embodiment, the spacing dimension N between each adjacent two spaced-through structures 110 can be any value between 5mm and 30mm or a range between any two values, for example, 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, etc.

[0091] As shown in FIG. 1, the shape of the spaced-through structure 110 can be freely set according to requirements, which can be a through-hole or a through-slot. In the embodiment, the spaced-through structure 110 is a through-slot, the length dimension of the spaced-through structure 110 is X, which satisfies 10mm≤X≤50mm, and the width dimension of the spaced-through structure 110 is Y, which satisfies 0.001mm≤Y≤2mm. By limiting the length dimension X and the width dimension Y of the spaced-through structure 110, the flow area of the spaced-through structure 110 is ensured, the speed of the electrolyte infiltrating into the pole group is improved, and meanwhile the insulation of the bottom covering area 101 is not affected by the spaced-through structure 110.

[0092] In the embodiment, the length dimension X of the spaced-through structure 110 can be any value between 10mm and 50mm or a range between any two values, for example, 10mm, 20mm, 30mm, 40mm, 50mm, etc., and the width dimension Y of the spaced-through structure 110 can be any value between 0.001mm and 2mm or a range between any two values, for example, 0.001mm, 0.01mm, 0.1mm, 1mm, 2mm, etc. In other embodiments, the spaced-through structure 110 can also be a whole through-slot.

[0093] Embodiment Two

[0094] Embodiment Two

[0095] The difference is that, in addition to the area limitation between the area covered after folding the first side covering area 103 and the second side covering area 104 and the overlapping area, the height ratio between the area covered after folding the first side covering area 103 and the second side covering area 104 and the overlapping area can also be limited, which can have the same effect as the area limitation.

[0096] The height dimension of the area covered after folding the first side covering area 103 and the second side covering area 104 is V, and the height dimension of the overlapping area after folding the first side covering area 103 and the second side covering area 104 is V1, and 3mm≤V1≤(0.6×V)mm is satisfied.

[0097] In order to verify the rationality of the height dimension V1 range of the overlapping area after folding the first side covering area 103 and the second side covering area 104, thirteen groups of examples and three groups of comparative examples are provided as shown in Table 2. Through the oscillation test of the battery cell, the working condition environment of the battery cell under vibration condition is simulated, and after standing for a period of time, whether the corrosion of the battery shell and the conduction of the battery shell caused by the destruction of the internal insulation environment occur is observed.

[0098] Table 2

[0099] In example 1, the height dimension V of the area covered after folding the first side covering area 103 and the second side covering area 104 is set to 84mm, and the height dimension V1 of the overlapping area after folding the first side covering area 103 and the second side covering area 104 is set to 3mm, so that it satisfies the set range of 3mm≤V1≤(0.6×V)mm. After the oscillation test, no corrosion of the battery shell and conduction of the battery shell caused by the destruction of the internal insulation environment were found after standing for three days.

[0100] In example 2, the height dimension V of the area covered after folding the first side covering area 103 and the second side covering area 104 is set to 84mm, and the height dimension V1 of the overlapping area after folding the first side covering area 103 and the second side covering area 104 is set to 8mm, so that it satisfies the set range of 3mm≤V1≤(0.6×V)mm. After the oscillation test, no corrosion of the battery shell and conduction of the battery shell caused by the destruction of the internal insulation environment were found after standing for three days.

[0101] In Example 3, the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 was set to 84 mm, and the height dimension VI of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 was set to 20 mm, so as to satisfy the set range of 3 mm ≤ VI ≤ (0.6 x V) mm. After the shock test, no corrosion of the battery case and no conduction of the battery case due to the destruction of the internal insulation environment were found after three days.

[0102] In Example 4, the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 was set to 84 mm, and the height dimension VI of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 was set to 30 mm, so as to satisfy the set range of 3 mm ≤ VI ≤ (0.6 x V) mm. After the shock test, no corrosion of the battery case and no conduction of the battery case due to the destruction of the internal insulation environment were found after three days.

[0103] In Example 5, the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 was set to 84 mm, and the height dimension VI of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 was set to 40 mm, so as to satisfy the set range of 3 mm ≤ VI ≤ (0.6 x V) mm. After the shock test, no corrosion of the battery case and no conduction of the battery case due to the destruction of the internal insulation environment were found after three days.

[0104] In Example 6, the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 was set to 84 mm, and the height dimension VI of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 was set to 48 mm, so as to satisfy the set range of 3 mm ≤ VI ≤ (0.6 x V) mm. After the shock test, no corrosion of the battery case and no conduction of the battery case due to the destruction of the internal insulation environment were found after three days.

[0105] In Example 7, the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 was set to 84 mm, and the height dimension VI of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 was set to 50.4 mm, so as to satisfy the set range of 3 mm ≤ VI ≤ (0.6 x V) mm. After the shock test, no corrosion of the battery case and no conduction of the battery case due to the destruction of the internal insulation environment were found after three days.

[0106] In Example 8, the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 was set to 50 mm, and the height dimension VI of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 was set to 30 mm, so as to satisfy the set range of 3 mm ≤ VI ≤ (0.6 x V) mm. After the shock test, no corrosion of the battery case and no conduction of the battery case due to the destruction of the internal insulation environment were found after three days.

[0107] In Example 9, the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 was set to 70 mm, and the height dimension VI of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 was set to 40 mm, so as to satisfy the set range of 3 mm ≤ VI ≤ (0.6 x V) mm. After the shock test, no corrosion of the battery case and no conduction of the battery case due to the destruction of the internal insulation environment were found after three days.

[0108] In Example 10, the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 was set to 100 mm, and the height dimension VI of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 was set to 60 mm, so as to satisfy the set range of 3 mm ≤ VI ≤ (0.6 x V) mm. After the shock test, no corrosion of the battery case and no conduction of the battery case due to the destruction of the internal insulation environment were found after three days.

[0109] In Example 11, the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 was set to 150 mm, and the height dimension VI of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 was set to 80 mm, so as to satisfy the set range of 3 mm ≤ VI ≤ (0.6 x V) mm. After the shock test, no corrosion of the battery case and no conduction of the battery case due to the destruction of the internal insulation environment were found after three days.

[0110] In Example 12, the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 was set to 200 mm, and the height dimension VI of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 was set to 120 mm, so as to satisfy the set range of 3 mm ≤ VI ≤ (0.6 x V) mm. After the shock test, no corrosion of the battery case and no conduction of the battery case due to the destruction of the internal insulation environment were found after three days.

[0111] In Example 13, the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 is set to 250 mm, and the height dimension V1 of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 is set to 150 mm, so as to satisfy the set range of 3 mm≤V1≤(0.6×V) mm. After the shock test, it is found that no corrosion occurs on the battery shell, and no conduction occurs on the battery shell due to the destruction of the internal insulation environment after being placed for three days.

[0112] From Examples 1 to 13, it can be seen that when the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 is set, and the height dimension V1 of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 satisfies the set range of 3 mm≤V1≤(0.6×V) mm, the shock test can be successfully passed, and no powder particles are detached due to vibration, the risk of corrosion of the battery shell and destruction of the internal insulation environment is reduced, the protection property is improved, and the service life of the battery is prolonged.

[0113] In Comparative Example 1, the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 is set to 84 mm, and the height dimension V1 of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 is set to -1 mm, so as to not satisfy the set range of 3 mm≤V1≤(0.6×V) mm. At this time, the first side covering area 103 does not have an overlapping area with the second side covering area 104, and a part of the side of the pole group is exposed. After the shock test, it is found that corrosion occurs on the battery shell, and conduction occurs on the battery shell due to the destruction of the internal insulation environment after being placed for three days.

[0114] In Comparative Example 2, the height dimension V of the area covered after folding of the first side covering area 103 and the second side covering area 104 is set to 84 mm, and the height dimension V1 of the overlapping area after folding of the first side covering area 103 and the second side covering area 104 is set to 1 mm, so as to not satisfy the set range of 3 mm≤V1≤(0.6×V) mm. At this time, the height dimension of the overlapping area of the first side covering area 103 and the second side covering area 104 is less than the set minimum value. After the shock test, it is found that corrosion occurs on the battery shell, and conduction occurs on the battery shell due to the destruction of the internal insulation environment after being placed for three days.

[0115] In the comparative example 3, the height dimension V of the area covered after the first side covering area 103 and the second side covering area 104 are folded is set to 84 mm, and the height dimension V1 of the overlapping area after the first side covering area 103 and the second side covering area 104 are folded is set to 55 mm, which does not satisfy the set range of 3 mm≤V1≤(0.6×V) mm. In this case, the height dimension of the overlapping area of the first side covering area 103 and the second side covering area 104 is greater than the set maximum value. After the shock test, it is found that the battery shell is corroded and the internal insulation environment is destroyed after being placed for three days, which leads to the conduction of the battery shell. However, the covering area is large, which leads to more use of the insulating film of the battery cell and higher cost.

[0116] As can be seen from the comparative examples 1 to 3, when the height dimension V of the area covered after the first side covering area 103 and the second side covering area 104 are folded is set, and the height dimension V1 of the overlapping area after the first side covering area 103 and the second side covering area 104 are folded is less than the minimum value of the set range, it is found that the battery shell is corroded and the internal insulation environment is destroyed after the shock test and being placed for three days, which leads to the conduction of the battery shell. When the height dimension V1 of the overlapping area after the first side covering area 103 and the second side covering area 104 are folded is greater than the maximum value of the set range, although it is found that the battery shell is not corroded and the internal insulation environment is not destroyed after the shock test and being placed for three days, which leads to the conduction of the battery shell, the covering area is large, which leads to more use of the insulating film of the battery cell and higher cost.

[0117] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents. Industrial applicability

[0118] The insulating film of the battery cell provided by the present application ensures that the side of the pole group overlaps with the insulating film body with sufficient area through the limitation of S and S1, so that the side of the pole group after being covered with the insulating film body has good buffering property, reduces the situation of powder particles falling off due to vibration, reduces the risk of corrosion of the battery cell shell and destruction of the internal insulation environment, improves the protection of the side of the pole group, and prolongs the service life of the battery.

Claims

1. An electric cell insulating film which is wrapped around the outside of a pole group and accommodated in an electric cell case, characterized by, The electric core insulation film comprises an insulation film body, the insulation film body comprises a bottom surface cladding area, an end surface cladding area, a first side surface cladding area and a second side surface cladding area, the bottom surface cladding area is connected with the first side surface cladding area on both sides along a first direction, the end surface cladding area is connected with the second side surface cladding area on both sides along the first direction, and the end surface cladding area is connected with the bottom surface cladding area on both sides along a second direction; The total area covered by the first side covering area and the second side covering area after folding is S1, the overlapping area of the first side covering area and the second side covering area after folding is S, and 5mm 2 ≤ S ≤ (0.6 x S1) mm 2 .

2. The cell insulation film according to claim 1, characterized by, A first crease and a second crease are arranged between each of the second side surface cladding areas and the end surface cladding area, and the two second creases on both sides of the end surface cladding area along the first direction are located inside the two first creases on both sides of the end surface cladding area along the first direction.

3. The cell insulation film according to claim 2, characterized by, The electric core shell comprises a shell, the shell comprises a shell side plate, a length size of the shell is A, a first thickness size of the shell side plate is B1, the first crease is arranged between the end surface cladding area and the second side surface cladding area connected on both sides of the end surface cladding area along the first direction, a first spacing size between the two first creases is L1, and (A-B1*2-5)mm≤L1≤(A-B1*2-0.1)mm is satisfied.

4. The cell insulation film according to claim 3, characterized by, The electric core shell further comprises a shell bottom plate, a cover plate body and a lower insulation piece connected to the inside of the cover plate body, a second thickness size of the lower insulation piece is B2, a third thickness size of the cover plate body is B3, a height size of the shell is C, and a fourth thickness size of the shell bottom plate is B4; A third crease is arranged between each of the end surface cladding area and the bottom surface cladding area, a second spacing size between the third crease and the boundary of the side of the end surface cladding area away from the bottom surface cladding area is L2, and (C-B4-B3-B2+3)mm≤L2≤(C-B4-B3-1)mm is satisfied.

5. The cell insulation film according to claim 4, characterized by A bending groove located between the end surface cladding area and the bottom surface cladding area is arranged on both sides of each of the third creases along the first direction; A groove width size of the bending groove is W, and 0.1mm≤W≤2mm is satisfied; And / or, a size of the bending groove extending in the direction close to the third crease is H, and 1mm≤H≤5mm is satisfied.

6. The cell insulation film according to claim 2, characterized by A third spacing size between one end of the first crease away from the bottom surface cladding area and the edge of the end surface cladding area away from the bottom surface cladding area along the second direction is L3, and 0.5mm≤L3≤5mm is satisfied, and a fourth spacing size between one end of the first crease close to the bottom surface cladding area and the edge of the end surface cladding area close to the bottom surface cladding area along the second direction is L4, and 0.5mm≤L4≤5mm is satisfied. And / or, a fifth interval dimension L5 between an end of the second crease away from the bottom surface cladding region and an edge of the end surface cladding region away from the bottom surface cladding region along the second direction is 0.5mm≤L5≤5mm, and a sixth interval dimension L6 between an end of the second crease close to the bottom surface cladding region and an edge of the end surface cladding region close to the bottom surface cladding region along the second direction is 0.5mm≤L6≤5mm.

7. The cell insulation film according to claim 2, characterized by, A seventh interval dimension L7 between the first crease and the second crease on the same side of the end surface cladding region along the first direction is 0mm≤L7≤8mm.

8. The cell insulation film according to claim 2, characterized by, A thickness dimension T of the insulating film body, a depth dimension T1 of the first crease is 1 / 3×T≤T1≤1 / 2×T; And / or, a depth dimension T2 of the second crease is 1 / 3×T≤T2≤1 / 2×T.

9. The cell insulation film according to claim 2, characterized by, An included angle θ1 between an edge of the first side surface cladding region close to one side of the second side surface cladding region and the first crease is 15°≤θ1≤90°; And / or, a fourth crease is arranged between each first side surface cladding region and the bottom surface cladding region, and an included angle θ2 between an edge of the first side surface cladding region close to one side of the second side surface cladding region and the fourth crease is 15°≤θ2≤90°.

10. The cell insulation film according to claim 1, characterized by, A plurality of spaced-through structures are further arranged on the bottom surface cladding region, and an interval dimension N between each adjacent two spaced-through structures along the first direction is 5mm≤N≤30mm.

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