Insulating protective film and battery cell

Abstract

The invention relates to the technical field of batteries, in particular to an insulating protective film and a battery cell. The insulating protective film is provided with a first coating area, a second coating area, a third coating area, a fourth coating area and a fifth coating area which are sequentially arranged in the first direction. The second coating area and the fourth coating area are arranged on two shell end faces in the length direction of the shell, and the first coating area, the third coating area and the fifth coating area are arranged on the shell side faces connected with the two shell end faces; notches are formed in the two ends, in the first direction and the second direction, of the second coating area and the fourth coating area; the minimum size w of the notch in the first direction is greater than or equal to 1 mm and less than or equal to 2 mm; the minimum distance between the two notches in the second direction is C, the size of the end face of the shell in the second direction is B, and C-B is larger than or equal to 2mm and smaller than or equal to 3.5 mm. The surface of the shell of the battery cell is directly and completely coated with the insulating protective film, the production process is simplified, the production efficiency is improved, and the production cost of the battery cell is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to an insulating protective film and a battery cell. Background Art

[0002] Lithium-ion batteries are currently widely used in various fields such as transportation power supply, electric energy storage power supply, new energy energy storage power supply, aerospace and military industry due to their large capacity, high operating voltage, strong charge retention ability and long cycle life.

[0003] The structure of a lithium-ion battery generally includes: a cover, a shell, an electrode group, an electrolyte, a bare cell insulating sheet, an external insulating structure, a cover top cover patch, etc., wherein the cover and the shell are fixed by welding to form an enclosed space for protecting the electrode group; the electrode group is coated with a bare cell insulating sheet to protect the electrode group and prevent the electrode group from contacting the shell and causing an internal short circuit in the cell; the external insulating structure includes a blue insulating tape and a top cover patch, wherein the blue insulating tape is coated on the outside of the shell and folded to a certain width at the edge of the cover, and then a layer of insulating protective top cover patch is applied on the cover.

[0004] At present, in order to improve the energy density of the entire battery pack, the thickness of the battery cell is getting thinner and thinner, resulting in the width of the battery cell cover becoming smaller and smaller. At the same time, the cover also integrates functional areas such as poles, explosion-proof valves, and injection holes that need to be avoided. As a result, the width of the blue film folded to the cover and the width of the top cover patch are very narrow, and the bonding area is small. During the battery cell process and subsequent use, problems such as the top cover patch warping, falling off, or the blue film warping often occur, posing a great risk to the safety performance of the battery cell. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide an insulating protective film and a battery cell to solve the problem that the existing insulating protective structure arranged on the outside of the battery cell is prone to warping and falling off during the battery cell manufacturing process and subsequent use, thereby reducing the safety performance of the battery cell.

[0006] A first aspect of the present invention provides an insulating protective film, which is coated on the surface of the shell of a battery cell, wherein the insulating protective film is formed with a first coating area, a second coating area, a third coating area, a fourth coating area and a fifth coating area arranged in sequence along a first direction; the second coating area and the fourth coating area are arranged on two shell end surfaces in the length direction of the shell, and the first coating area, the third coating area and the fifth coating area are arranged on the side surfaces of the shell respectively connected to the two shell end surfaces; the second coating area and the fourth coating area are both provided with cutouts at both ends in the first direction and the second direction;

[0007] The minimum size of the incision in the first direction is w, 1mm≤w≤2mm;

[0008] And / or, the minimum distance between the two cutouts in the second direction is C, the dimension of the shell end surface in the second direction is B, and 2mm≤CB≤3.5mm.

[0009] Preferably, the housing side comprises two first side surfaces that are opposite to each other and arranged at intervals, and two second side surfaces that are opposite to each other and arranged at intervals, and the first side surface is arranged between the two second side surfaces;

[0010] A portion of the third cladding region is disposed on one of the two first side surfaces, and a portion of the first cladding region and a portion of the fifth cladding region are disposed on the other of the two first side surfaces.

[0011] Preferably, one end of the first encapsulating area away from the second encapsulating area and one end of the fifth encapsulating area away from the fourth encapsulating area overlap each other to form a first overlapping area; the size of the first overlapping area in the length direction of the shell is L1, 10mm≤L1≤25mm.

[0012] Preferably, flange portions arranged on the second side surface are formed at both ends of the first covering area, the second covering area, the third covering area, the fourth covering area and the fifth covering area in the second direction.

[0013] Preferably, the flanged portions on the first covering area and the fifth covering area can overlap with the flanged portion on the third covering area to form a second overlapping area, and the size of the second overlapping area in a direction perpendicular to the first side surface is L2, 5mm≤L2≤10mm.

[0014] Preferably, the area of ​​the first side surface is greater than the area of ​​the second side surface.

[0015] Preferably, a functional area is arranged on the end surface of the shell, and an opening for exposing the functional area is arranged on the second covering area and / or the fourth covering area.

[0016] Preferably, the cutouts of the ends of the second cladding region and the fourth cladding region in the second direction form an angle β, 95°≤β≤115°.

[0017] Preferably, the cutout is formed into a trapezoidal structure, and w is the size of the upper base of the trapezoidal structure;

[0018] And / or, the first direction is the length direction of the insulating protection film, and the second direction is the width direction of the insulating protection film.

[0019] A second aspect of the present invention provides a battery cell, comprising the insulating protective film described in any of the above technical solutions.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The insulating protective film of the present invention eliminates the top cover patch in the external insulation structure of the traditional battery cell. The second coating area and the fourth coating area are arranged on the two shell end faces in the length direction of the shell, and the first coating area, the third coating area and the fifth coating area are arranged on the side faces of the shell respectively connected to the two end faces, so that the insulating protective film can directly and completely cover the shell surface of the battery cell, increase the adhesion area of ​​the insulating protective film to the battery cell with a smaller thickness, simplify the production process, improve production efficiency, and reduce the production cost of the battery cell; the second coating area and the fourth coating area are provided with incisions at both ends in the first direction and the second direction; the minimum size of the incision in the first direction is w, 1mm≤w≤2mm; and / or, the minimum distance between the two incisions in the second direction is C, and the size of the shell end face in the second direction is B, 2mm≤CB≤3.5mm, so as to avoid the insulating protective film from warping, and the overall insulation performance of the battery cell after being coated with the insulating protective film is guaranteed, the insulation withstand voltage requirements of the battery cell are met, and the battery cell process yield is also guaranteed.

[0022] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A schematic diagram of the structure of an insulating protective film provided by an embodiment of the present invention;

[0025] Figure 2 A schematic diagram of a structure in which an insulating protective film provided in an embodiment of the present invention is arranged on an end of a housing;

[0026] Figure 3 for Figure 2 A schematic diagram of the enlarged structure at A in the middle;

[0027] Figure 4 A schematic diagram of a structure in which an insulating protective film provided in an embodiment of the present invention is arranged on an end portion of a housing and on a portion of a side surface of the housing;

[0028] Figure 5 A schematic diagram of a structure in which the insulating protective film provided in an embodiment of the present invention covers the entire surface of the housing;

[0029] Figure 6 A schematic structural diagram from another perspective of an insulating protective film provided by an embodiment of the present invention covering the entire housing surface.

[0030] Icons: 10-first coating area; 20-second coating area; 30-third coating area; 40-fourth coating area; 50-fifth coating area; 60-flanged portion; 70-incision; 80-opening; 91-first overlapping area; 92-second overlapping area; 100-shell end face; 200-shell side face; 201-first side face; 202-second side face; 300-pressure relief member; 400-pole; D1-first direction; D2-second direction. DETAILED DESCRIPTION

[0031] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be apparent. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but in addition to the operations that must occur in a particular order, changes that will be apparent after understanding the disclosure of the present application may be made. In addition, in order to improve clarity and brevity, descriptions of features known in the art may be omitted.

[0032] The features described herein may be implemented in different forms and should not be interpreted as being limited to the examples described herein. Rather, the examples described herein have been provided only to illustrate some of the many possible ways of implementing the methods, devices and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0033] Throughout the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, “bound to”, “over”, or “covering” another element, it may be directly “on”, “connected to”, “bound to”, “over”, or “covering” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on”, “directly connected to”, “directly bound to”, “directly over”, or “directly covering” another element, there may be no other elements present between them.

[0034] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0035] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, component, region, layer, or portion referred to may also be referred to as the second member, component, region, layer, or portion.

[0036] For ease of description, spatial relational terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatial relational terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element will subsequently be "below" or "lower" relative to the other element. Therefore, the term "above" includes both "above" and "below" orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relational terms used herein will be interpreted accordingly.

[0037] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprise" and "have" list the stated features, quantities, operations, components, elements and / or their combinations that exist, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0038] Variations in the shapes shown in the drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include variations in shapes that occur during manufacturing.

[0039] The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0040] According to a first aspect of the present invention, an insulating protective film is provided.

[0041] Hereinafter, a specific structure of the insulating protective film according to the present embodiment will be described.

[0042] In this embodiment, if Figures 4 to 6 As shown, the insulating protective film is coated on the outer shell surface of the battery core, and the insulating protective film can be a PET film (i.e., a blue film in the prior art). Specifically, Figure 1 As shown, in the unfolded state of the insulating protective film, a first coating area 10, a second coating area 20, a third coating area 30, a fourth coating area 40 and a fifth coating area 50 arranged in sequence along a first direction D1 are formed on the insulating protective film, and the first direction D1 is the length direction of the insulating protective film, wherein the second coating area 20 and the fourth coating area 40 are arranged on two shell end surfaces 100 in the length direction of the shell, for example, the second coating area 20 and the fourth coating area 40 can be arranged on the cover of the blade battery cell, and the second coating area 20 and the fourth coating area 40 can also be arranged on the cover of the square shell battery cell and on the bottom of the shell, and the first coating area The first coating zone 10, the third coating zone 30 and the fifth coating zone 50 are arranged on the side surfaces 200 of the shell respectively connected to the two end surfaces 100 of the shell, that is, the first coating zone 10, the third coating zone 30 and the fifth coating zone 50 can be arranged on the shell of the blade battery cell, and can also be arranged on the side of the shell of the square shell battery cell, so that the insulating protective film can completely cover the surface of the battery cell shell, thereby eliminating the top cover patch in the traditional battery cell structure, increasing the bonding area of ​​the insulating protective film to the battery cell with smaller thickness, avoiding the occurrence of warping of the top cover patch, and also simplifying the production process, improving production efficiency, and reducing the production cost of the battery cell.

[0043] In this embodiment, the insulating protective film is formed into a rectangular film-like structure in the unfolded state.

[0044] Specifically, if Figures 1 to 3 As shown, the second coating area 20 and the fourth coating area 40 are both provided with cutouts 70 at both ends in the first direction D1 and the second direction D2, that is, the cutouts 70 are provided at the four corners of the second coating area 20 and the fourth coating area 40, so that the two ends of the second coating area 20 in the second direction D2 are disconnected from the first coating area 10 and the third coating area 30 (that is, the middle part of the second coating area 20 is respectively connected to the first coating area 10 and the third coating area 30, and the cutouts 70 make the first coating area 10 and the third coating area 30 in the second direction D2 disconnected from the first coating area 10 and the third coating area 30. The ends of the fourth coating area 40 are separated from the second coating area 20), and the two ends of the fourth coating area 40 in the second direction D2 are disconnected from the third coating area 30 and the fifth coating area 50 (that is, the middle part of the fourth coating area 40 remains connected to the third coating area 30 and the fifth coating area 50 respectively, and the incision 70 separates the third coating area 30 and the fifth coating area 50 from the fourth coating area 40 at both ends D2 in the second direction), so as to achieve complete coating of the side surface 200 of the shell. In this embodiment, the second direction D2 is the width direction of the insulating protective film.

[0045] In this embodiment, if Figure 3 As shown, the minimum dimension of the incision 70 in the first direction D1 is w, 1mm≤w≤2mm; and / or, the minimum distance between the two incisions 70 in the second direction D2 is C, and the dimension of the shell end face 100 in the second direction D2 is B, 2mm≤CB≤3.5mm. This ensures that the insulating protective film completely covers the battery cell shell (i.e., including the shell and the cover plate), and the covering is smooth, avoiding the insulating protective film from warping or unevenness. After the insulating protective film is coated, the overall insulation performance of the battery cell is guaranteed, which meets the insulation withstand voltage requirements of the battery cell and also ensures the battery cell process yield.

[0046] Furthermore, in this embodiment, if Figures 4 to 6 As shown, the battery cell is a blade battery cell or a square shell battery cell, so that the outer shell of the battery cell is formed into a rectangular structure with a cavity inside, and the outer shell side 200 includes two first sides 201 opposite to each other and arranged at intervals and two second sides 202 opposite to each other and arranged at intervals, and the first side 201 is arranged between the two second sides 202. The first side 201 and the second side 202 can be rectangular plate structures and are perpendicular to each other.

[0047] In this embodiment, if Figures 4 to 6 As shown, part of the third coating region 30 is arranged on one of the two first side surfaces 201, and part of the first coating region 10 and part of the fifth coating region 50 are arranged on the other of the two first side surfaces 201, so that the third coating region 30 alone coats one first side surface 201, while the first coating region 10 and the fifth coating region 50 located at both ends in the length direction of the insulating protective film jointly coat the other first side surface 201.

[0048] Furthermore, in this embodiment, if Figure 5 and Figure 6 As shown, one end of the first encapsulation area 10 away from the second encapsulation area 20 and one end of the fifth encapsulation area 50 away from the fourth encapsulation area 40 overlap each other to form a first overlapping area 91, so that part of the first encapsulation area 10 and part of the fifth encapsulation area 50 overlap, thereby ensuring complete covering of the first side surface 201 to improve the insulation performance of the battery cell; preferably, the size of the first overlapping area 91 in the length direction of the shell is L1, 10mm≤L1≤25mm, so as to ensure reliable insulation and save costs.

[0049] In this embodiment, if Figures 1 to 6As shown, the first coating area 10, the second coating area 20, the third coating area 30, the fourth coating area 40 and the fifth coating area 50 are formed with flange portions 60 arranged on the second side surface 202 at both ends in the second direction D2, so that the flange portions 60 on the first coating area 10, the second coating area 20, the third coating area 30, the fourth coating area 40 and the fifth coating area 50 are bent along the edges of the battery cell casing, and the flange portions 60 are overlapped with each other to complete the coating of the two second side surfaces 202.

[0050] Furthermore, in this embodiment, if Figure 4 As shown, the flange portions 60 on the first coating area 10 and the fifth coating area 50 can overlap with the flange portions 60 on the third coating area 30 to form a second overlapping area 92, so as to ensure complete covering of the second side surface 202 to improve the insulation performance of the battery cell. Preferably, the size of the second overlapping area 92 in a direction perpendicular to the first side surface 201 (i.e., in the thickness direction of the battery cell) is L2, 5mm≤L2≤10mm, thereby ensuring reliable insulation and saving costs.

[0051] In a preferred embodiment, Figure 4 As shown, the flange portions 60 on the third coating area 30, the first coating area 10 and the fifth coating area 50 are first bent to overlap each other to ensure complete coverage of the second side surface 202, and then the flange portions 60 on the second coating area 20 and the fourth coating area 40 are bent to cover the two end portions of the second overlapping area 92 in the length direction thereof, thereby reducing the risk of warping of the insulating protective film and further improving the reliability of the insulating protection of the battery cell by the insulating protective film.

[0052] Preferably, if Figures 4 to 6 As shown, the area of ​​the first side surface 201 is larger than the area of ​​the second side surface 202, so that the shell side surface 200 with a relatively larger area can be pasted first and then the shell side surface 200 with a relatively smaller area can be pasted, which is convenient for positioning the first coating area 10, the third coating area 30 and the fifth coating area 50 on the shell side surface 200, thereby improving the flatness of the insulating protective film and avoiding skewing or wrinkles.

[0053] In a preferred embodiment, Figures 1 to 3 As shown, the cutout 70 is formed into a trapezoidal structure, w is the size of the upper base of the trapezoidal structure (the upper base and the lower base in the trapezoidal structure are parallel to each other, and the upper base refers to the side with the smaller size), so that the cutout 70 is formed into an expanding structure that gradually expands outward along the second direction D2, so that the part between the two cutouts 70 is bent onto the second side surface 202 without warping. The trapezoidal structure can be a right-angled trapezoid, so as not to affect the area of ​​the flange portion 60 on the first encapsulation area 10, the third encapsulation area 30 or the fifth encapsulation area 50, and ensure complete coverage of the second side surface 202.

[0054] In addition, in this embodiment, Figures 1 to 6 As shown, a functional area is provided on the end face 100 of the shell, and an opening 80 for exposing the functional area is provided on the second coating area 20 and / or the fourth coating area 40 to meet the detection and use requirements of the battery cell, and the opening 80 is a through-hole structure. Specifically, in the present embodiment, the functional area is provided with a pressure relief member 300 for reducing the risk of failure of the battery cell and a pole 400 for realizing the transmission of electric energy inside and outside the battery cell, wherein the pressure relief member 300 can be an explosion-proof valve, and the part of the pole 400 arranged outside the battery cell can pass through the opening 80 on the insulating protective film, however, the structural part arranged in the functional area is limited to, and structures such as injection holes can also be arranged. It should be noted that the setting position, shape and size of the opening 80 on the second coating area 20 and / or the fourth coating area 40 are set according to the design layout of the functional area.

[0055] like Figure 2 As shown, in a preferred embodiment, the second coating area 20 or the fourth coating area 40 is first pasted on a shell end face 100 to achieve the positioning of the insulating protective film, and then the third coating area 30 and the first coating area 10 or the third coating area 30 and the fifth coating area 50 are respectively pasted on the two first side surfaces 201, and then the flange portion 60 is bent so that the flange portion 60 is pasted on the second side surface 202, and finally the fourth coating area 40 and the fifth coating area 50 or the second coating area 20 and the first coating area 10 are pasted.

[0056] In a preferred embodiment, Figure 3 As shown, the cut angles of the ends of the second coating area 20 and the fourth coating area 40 in the second direction D2 are β, 95°≤β≤115°, which further avoids the warping of the insulating protective film, thereby further improving the overall insulation performance of the battery cell after being coated with the insulating protective film.

[0057] Next, the insulating protective films with different CB, w and β parameters are assembled with the battery cells, and the assembly quality of the insulating protective films is tested to verify whether the limiting conditions described above are reliable. In each embodiment, multiple groups of insulating protective films and battery cell cover plates of the same size are assembled to ensure the accuracy and reliability of the test results. The test results are shown in Tables 1, 2 and 3 below, where Table 1 is used to test the reliability of the limiting conditions of 2mm≤CB≤3.5mm, Table 2 is used to test the reliability of the limiting conditions of 1mm≤w≤2mm, and Table 3 is used to test the reliability of the limiting conditions of 95°≤β≤115°.

[0058] Table 1

[0059] CB w / mm β / ° Test results Example 1-1 1.0 1 100 The proportion of poor insulation of coated cells is relatively high, accounting for about 0.093% Example 1-2 1.5 1 100 The proportion of poor insulation of coated cells is relatively high, accounting for about 0.085% Examples 1-3 2.0 1 100 The problem of poor insulation of the battery cells after coating is rare, accounting for about 0.015% Examples 1-4 2.5 1 100 There are very few problems with poor insulation of the battery cells after coating, accounting for about 0.0081% Examples 1-5 3.0 1 100 There are few problems with poor insulation of the battery cells after coating, accounting for about 0.0068% Examples 1-6 3.5 1 100 There are few problems with poor insulation of the battery cells after coating, accounting for about 0.058% Examples 1-7 4.0 1 100 The surface is not smooth after coating, and the defective rate of battery appearance is high. Examples 1-8 4.5 1 100 The surface is not smooth after coating, and the defective rate of battery appearance is high.

[0060] As shown in Table 1, if the size of C is too small, the poor insulation rate of the battery cell is high. If the size of C is too large, the position of the cutout 70 is inappropriate, resulting in uneven coating after film coating, which affects the appearance of the battery cell.

[0061] Table 2

[0062]

[0063] As shown in Table 2, if the size of w is too large, the poor insulation rate of the battery cell is high; if the size of w is too small, the folded parts of different coating areas are likely to interfere with each other when bending, resulting in unevenness after coating, affecting the appearance of the battery cell.

[0064] Table 3

[0065]

[0066] As shown in Table 3, if the size of β is too large, the poor insulation rate of the battery cell is high; if the size of β is too small, the flanged portion 60 on the second coating area 20 and the fourth coating area 40 is located at the rounded corner of the shell after bending, which is easy to warp, affecting the appearance and safety performance of the battery cell.

[0067] According to an insulating protective film provided by the present invention, the top cover patch in the external insulation structure of a traditional battery cell is omitted, and the second coating area and the fourth coating area are arranged on the two end faces of the shell in the length direction of the shell, and the first coating area, the third coating area and the fifth coating area are arranged on the side faces of the shell respectively connected to the two end faces, so that the insulating protective film directly covers the shell surface of the battery cell completely, simplifies the production process and improves production efficiency; the second coating area and the fourth coating area are provided with incisions at both ends in the first direction and the second direction; the minimum size of the incision in the first direction is w, 1mm≤w≤2mm; and / or the minimum distance between the two incisions in the second direction is C, and the size of the shell end face in the second direction is B, 2mm≤CB≤3.5mm, so as to avoid the insulating protective film from warping, and the overall insulation performance of the battery cell after being coated with the insulating protective film is guaranteed.

[0068] According to a battery cell provided by the present invention, the insulating protective film as described above completely covers the outer shell surface of the battery cell, so that the overall insulation performance of the battery cell is guaranteed after the insulating protective film is coated, meeting the insulation withstand voltage requirements of the battery cell, and also ensuring the battery cell process yield on the battery cell cover plate of the battery cell, thereby improving the safety performance and insulation performance of the battery cell and the production yield of the battery cell, and also reducing the production cost of the battery cell.

[0069] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An insulating protective film, coated on the outer shell surface of a battery cell, characterized in that: The insulating protective film is formed with a first coating area, a second coating area, a third coating area, a fourth coating area and a fifth coating area arranged in sequence along the first direction; the second coating area and the fourth coating area are arranged on two shell end surfaces in the length direction of the shell, and the first coating area, the third coating area and the fifth coating area are arranged on the shell side surfaces respectively connected to the two shell end surfaces; the second coating area and the fourth coating area are both provided with cutouts at both ends in the first direction and the second direction; The minimum size of the incision in the first direction is w, 1mm≤w≤2mm; And / or, the minimum distance between the two cutouts in the second direction is C, the dimension of the shell end surface in the second direction is B, and 2mm≤CB≤3.5mm.

2. The insulating protective film according to claim 1, characterized in that: The housing side comprises two first side surfaces that are opposite to each other and arranged at intervals, and two second side surfaces that are opposite to each other and arranged at intervals, wherein the first side surface is arranged between the two second side surfaces; A portion of the third cladding region is disposed on one of the two first side surfaces, and a portion of the first cladding region and a portion of the fifth cladding region are disposed on the other of the two first side surfaces.

3. The insulating protective film according to claim 2, characterized in that: One end of the first encapsulating area away from the second encapsulating area and one end of the fifth encapsulating area away from the fourth encapsulating area overlap each other to form a first overlapping area; a dimension of the first overlapping area in the length direction of the shell is L1, 10mm≤L1≤25mm.

4. The insulating protective film according to claim 2, characterized in that: Both ends of the first covering area, the second covering area, the third covering area, the fourth covering area and the fifth covering area in the second direction are formed with flange portions arranged on the second side surface.

5. The insulating protective film according to claim 4, characterized in that: The flanged portions on the first covering area and the fifth covering area can overlap with the flanged portion on the third covering area to form a second overlapping area, and a dimension of the second overlapping area in a direction perpendicular to the first side surface is L2, 5mm≤L2≤10mm.

6. The insulating protective film according to claim 2, characterized in that: An area of ​​the first side surface is greater than an area of ​​the second side surface.

7. The insulating protective film according to claim 1, characterized in that: A functional area is arranged on the end surface of the shell, and an opening for exposing the functional area is arranged on the second covering area and / or the fourth covering area.

8. The insulating protective film according to claim 1, characterized in that: The cut angles of the ends of the second cladding region and the fourth cladding region in the second direction are β, and 95°≤β≤115°.

9. The insulating protective film according to claim 1, characterized in that: The cutout is formed into a trapezoidal structure, and w is the size of the upper base of the trapezoidal structure; And / or, the first direction is the length direction of the insulating protection film, and the second direction is the width direction of the insulating protection film.

10. A battery cell, characterized in that: The insulating protective film comprises the insulating protective film according to any one of claims 1 to 9.

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