Insulating film structure, battery and electric device

Abstract

The utility model relates to an insulating film structure, a battery and an electric device. An insulating film structure is used for coating a battery cell, the battery cell comprises a plurality of stacked roll cores, and the insulating film structure comprises an insulating film base body, a plurality of insulating layers and a plurality of insulating layers, flame retardant is arranged in the bag bodies, and the bag bodies are arranged on the side, used for being in contact with the battery cell, of the insulating film base body. The bag body is accommodated in the insulating film, when the battery cell is impacted, the bag body is broken, or when the battery cell is abnormally high in temperature, the bag body melts, and the flame retardant can be released into the battery cell, so that the conductivity of the battery is reduced, and short circuit and delay of the battery or thermal runaway of the battery are avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to an insulating film structure, a battery and an electrical device. Background Art

[0002] With the continuous development of battery technology, the application scope of secondary batteries represented by lithium-ion batteries is becoming more and more extensive, including power tools, mobile terminals, electric bicycles, electric motorcycles and electric vehicles. Secondary batteries may generate heat during the charging and discharging process, which poses a safety hazard. Including thermal runaway when hit, leading to serious accidents such as fire or explosion.

[0003] In conventional technology, secondary battery shells are designed to prevent explosions, but in practice, the thermal runaway protection effect of batteries is poor. Utility Model Content

[0004] Based on this, it is necessary to provide an insulating film structure, a battery and an electrical device to address the problem of thermal runaway and explosion of secondary batteries.

[0005] In a first aspect, the present application provides an insulating film structure for coating a battery cell, wherein the battery cell comprises a plurality of stacked winding cores, and the insulating film structure comprises:

[0006] Insulating film substrate;

[0007] More than one bag body, wherein a flame retardant is arranged inside the bag body, and the bag body is arranged on a side of the insulating film substrate for contacting the battery core.

[0008] In one of the embodiments, when the insulating film substrate covers the battery core, the bag body is located in a space formed by the insulating film substrate and the R angle of the winding core.

[0009] In one embodiment, the insulating film substrate comprises:

[0010] A first film body is used to cover the first side surface, at least a portion of the second side surface and at least a portion of the third side surface of the battery cell; the second side surface is opposite to the third side surface;

[0011] A second film body is used to cover a fourth side surface of the battery core, at least a portion of the second side surface, and at least a portion of the third side surface; the fourth side surface is opposite to the first side surface; and

[0012] The third film body is used to cover the bottom surface, at least a part of the second side surface and at least a part of the third side surface of the battery cell. One side of the third film body is connected to the first film body, and the other opposite side is connected to the second film body.

[0013] In one embodiment, the portion of the first film body used for covering the second side surface and the portion of the first film body used for covering the third side surface are provided with the bag body; and / or

[0014] The bag body is provided on a portion of the second film body used for covering the second side surface and a portion of the second film body used for covering the third side surface.

[0015] In one of the embodiments, the insulating film structure includes a plurality of bag bodies, and the plurality of bag bodies are arranged at intervals, wherein the interval distance between two bag bodies = (core thickness × n), where n is a positive integer.

[0016] In one embodiment, the bag body has a width less than 60 mm and a thickness less than 30 mm.

[0017] In one embodiment, the bag body is made of one of polyethylene, polypropylene, and polyethylene terephthalate.

[0018] In one embodiment, the flame retardant is a phosphorus-containing flame retardant and / or a halogen-based flame retardant.

[0019] In a second aspect, the present application further provides a battery, comprising:

[0020] A battery cell, comprising a plurality of stacked cores;

[0021] The insulating film structure;

[0022] A top cover structure, arranged on the top surface of the battery cell;

[0023] The battery shell is a top-open structure, and the accommodating cavity formed is used to accommodate the battery core wrapped with the insulating film structure.

[0024] In a third aspect, the present application further provides an electrical device, wherein the electrical device comprises the battery.

[0025] The above-mentioned insulating film structure, battery and electrical device include an insulating film substrate and one or more bags containing flame retardants, and the bags are arranged on the side of the insulating film substrate that contacts the battery cell. In this way, the bag is contained in the insulating film, and when the battery cell is hit, the bag breaks, or when the battery cell is abnormally hot, the bag melts, and the flame retardant is released into the battery cell, reducing the battery conductivity, avoiding the battery from short circuit, and reducing the interface side reaction, reducing the heat generation, and thus delaying or avoiding the battery from thermal runaway, such as combustion or explosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is a schematic structural diagram of an insulating film structure in one embodiment;

[0027] FIG2 is a schematic diagram of the structure of a battery cell without an insulating film;

[0028] Figure 3 It is a cross-sectional view of a battery cell covered with an insulating film when no bag body is provided;

[0029] Figure 4 It is a schematic diagram of the structure of the insulating film structure covering the battery core when a bag body is provided in one embodiment;

[0030] Figure 5 It is a stereoscopic view of the first film body and the second film body being wrapped in one embodiment.

[0031] Description of reference numerals:

[0032] 10. Insulating film structure; 11. Insulating film substrate; 111. First film body; 112. Second film body; 113. Third film body; 12. Bag body; 20. Battery cell; 21. Winding core; 22. R angle; 30. Top cover structure; 31. Positive electrode column; 32. Negative electrode column; S1. First side surface; S2. Second side surface. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0036] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0038] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0039] Secondary batteries represented by lithium-ion batteries are usually mainly composed of a battery cell made by winding a pole piece prepared by coating slurry, a polymer insulating film wrapped around the battery cell, an electrolyte, and a battery metal structure. Among them, the main structural devices for storing electrical energy are the battery cell and the electrolyte. Due to the chemical characteristics of lithium-ion batteries, once there is direct contact or short circuit between the positive and negative electrodes, it may cause a large amount of battery discharge, release a large amount of heat in a short period of time, and then cause a fire or explosion.

[0040] There are two types of insulating films for traditional lithium-ion batteries, including a blue film used on the outside of the battery shell and an insulating film used to wrap the battery cell inside the battery shell. Optionally, the insulating film can be a Mylar film (also called Mylar film). The insulating film is an insulating plastic film, usually made of polyester film (PET, Polyethylene terephthalate), which has high temperature, high strength and high insulation properties. It is used to wrap the battery cell to provide protection for the battery cell, prevent the impact of external substances and the environment on the battery, and prevent the positive and negative electrodes inside the battery from short-circuiting. However, the existing insulating film has a simple structure, and the safety protection effect is limited when the positive and negative electrodes of the lithium-ion battery are in contact and short-circuited.

[0041] In order to slow down the burning speed of secondary batteries such as lithium-ion batteries and prolong the fire-fighting time, the utility model provides an insulating film structure 10. Referring to FIG1 , FIG1 shows a schematic structural diagram of an insulating film structure 10 in an embodiment of the utility model. The insulating film structure 10 provided in an embodiment of the utility model is used to wrap a battery cell 20, and the battery cell 20 includes a plurality of stacked winding cores 21. The insulating film structure 10 includes: an insulating film substrate 11 and one or more bag bodies 12, and a flame retardant is arranged inside the bag body 12. The bag body 12 is arranged on the side of the insulating film substrate 11 for contacting the battery cell 20, so that when the insulating film wraps the battery cell 20, the bag body 12 is also wrapped inside. When the battery cell 20 is hit or at an abnormally high temperature, the bag body 12 ruptures to release the flame retardant, and the flame retardant penetrates into the winding core 21, reducing the battery conductivity, avoiding the battery from short circuiting, and reducing the interface side reaction, reducing the heat generation, and thus delaying or avoiding the battery from thermal runaway.

[0042] Specifically, the position of the bag body 12 in the insulating film substrate 11 satisfies: when the insulating film substrate 11 covers the battery cell 20, the bag body 12 is located in the space formed by the R angle of the insulating film substrate 11 and the winding core 21, so that the winding core 21 is adjacent to the bag body 12, and does not occupy more internal space of the battery. Optionally, only one bag body 12 may be provided, or multiple bag bodies 12 may be provided. When multiple bag bodies 12 are included, the multiple bag bodies 12 may be respectively located at the R angles of different winding cores 21 in the battery cell 20. Furthermore, when multiple bag bodies 12 are provided, they may be evenly distributed in the battery cell 20. In a feasible implementation, the bag body 12 may be provided on the insulating film substrate 11 by bonding, such as bonding by an adhesive.

[0043] Referring to FIG. 2 , FIG. 2 shows a schematic diagram of the structure of the battery cell 20 without the insulating film. The battery cell 20 includes a plurality of winding cores 21. In the preparation process of the lithium battery, the plurality of winding cores 21 are stacked and arranged. The positive electrodes of the plurality of winding cores 21 are electrically connected to form the positive electrode of the battery cell 20 and are led out through the positive electrode column 31 of the top cover structure 30. The negative electrodes of the plurality of winding cores 21 are electrically connected to form the negative electrode of the battery cell 20 and are led out through the negative electrode column 32 of the top cover structure 30.

[0044] As shown in FIG2 , the side of the winding core 21 is an arc-shaped structure. The arc-shaped structures of the side of adjacent winding cores 21 cannot directly contact each other but form a cone-shaped space. The outermost winding core 21 also forms a cone-shaped space. Figure 3 As shown, Figure 3 A cross-sectional view of an insulating film-wrapped battery cell 20 without the bag body 12 is shown. An accommodating space 22 is formed between the R corner of the winding core 21 and the insulating film substrate 11 , and the accommodating space 22 can accommodate the bag body 12 .

[0045] like Figure 4 As shown, Figure 4 The schematic diagram of the structure of the insulating film structure 10 enclosing the battery cell 20 in one embodiment is shown. The bag body 12 is indicated by a dotted line, indicating that the bag body 12 is located inside the insulating film substrate 11, that is, in the accommodation space 22 formed by the R corner area.

[0046] In particular, the R angles of two adjacent winding cores 21 are merged to form a larger cone-shaped space with the insulating film substrate 11. In a feasible implementation, the bag body 12 is contained in the cone-shaped containing space 22, so that the bag body 12 can have a larger volume, contain more flame retardant, release more flame retardant when melted by heat or ruptured by impact, and improve safety. It should be noted that the utility model does not limit the number of winding cores 21 in the battery cell 20. Figure 3 The structure of the battery cell 20 including two winding cores 21 is only schematically shown.

[0047] The above-mentioned insulating film structure 10 includes an insulating film substrate 11 and one or more bags 12 filled with flame retardants. The bags 12 are arranged on the side where the insulating film substrate 11 contacts the battery cell 20, and the position of the bags 12 is designed so that when the insulating film substrate 11 covers the battery cell 20, the bags 12 are located in the space formed by the R angle of the insulating film substrate 11 and the winding core 21. With this arrangement, on the one hand, the bags 12 will not occupy additional battery space, and on the other hand, the bags 12 are contained in the insulating film. When the battery cell 20 is hit, the bags 12 rupture, or when the battery cell 20 is abnormally hot, the bags 12 melt, and the flame retardants are released into the battery cell 20, which reduces the battery conductivity and avoids the battery from short circuiting. It can also reduce the interface side reactions and reduce the heat generation, thereby delaying or avoiding the battery from thermal runaway, such as combustion or explosion.

[0048] In some embodiments, the material of the bag body 12 includes at least one of polyethylene, polypropylene, and polyethylene terephthalate. It should be noted that the optional materials of the bag body 12 mentioned above are all existing known materials. In this way, the bag body 12 has good chemical stability and will not affect the normal charging and discharging efficiency of the battery. When the abnormal temperature of the battery rises to the melting point of the bag body 12, the bag body 12 melts, and the flame retardant inside the bag body 12 is released into the battery cell 20 to prevent the battery cell 20 from exploding. When the battery is hit to a greater extent, the internal pressure of the bag body 12 increases, and it can also rupture itself to release the flame retardant.

[0049] In order to improve the thermal runaway protection effect of the battery and prevent or slow down the spread of flames, in some embodiments, the flame retardant may include phosphorus-containing flame retardants, halogen flame retardants, nitrogen flame retardants, inorganic flame retardants, fluorine-containing flame retardants, etc. When the bag body 12 is broken, the flame retardant can enter the battery cell 20 to achieve a flame retardant effect.

[0050] In some embodiments, the flame retardant includes a phosphorus-containing flame retardant and / or a halogen-based flame retardant. The phosphorus-containing flame retardant contains phosphorus, which can react with free radicals released during combustion to form phosphorus compounds, thereby hindering the propagation of the combustion chain during the combustion process and achieving a flame retardant effect. Halogen-based flame retardants are compounds containing halogens (such as bromine, chlorine, etc.), which release compounds such as hydrogen halides during combustion. These compounds can react with free radicals to prevent the spread of flames. In this way, after the flame retardant is released into the battery cell 20, it can delay the combustion of the battery cell 20 and achieve a flame retardant effect.

[0051] Optionally, the phosphorus-containing flame retardant includes one or more of trimethyl phosphate, tripropyl phosphate, triphenyl phosphate, tributyl phosphate, tri(2-ethylhexyl) phosphate, tri(2-chloroethyl) phosphate, tri(2,3-dichloropropyl) phosphate, and tri(2,3-dibromopropyl) phosphate. Further, the phosphorus-containing flame retardant may also include one or more of ethoxy (pentafluoro) cyclotriphosphazene, hexachlorocyclotriphosphazene, hexaphenylcyclotriphosphazene, and hexaphenoxycyclotriphosphazene.

[0052] Optionally, the halogen flame retardant includes one or more of dibromomethane, bromotrichloromethane, bromodichloromethane, and pentabromoethylbenzene. Further, the halogen flame retardant may also include one or more of hexabromobiphenyl, polybrominated biphenyl, brominated polystyrene, chlorinated polyethylene, and chlorinated polypropylene.

[0053] It should be noted that the optional materials for the flame retardants mentioned above are all existing known materials.

[0054] In some embodiments, the insulating film structure 10 includes a plurality of bag bodies 12, and the plurality of bag bodies 12 are arranged at intervals, wherein the interval between two bag bodies 12 = (core thickness × n), where n is a positive integer. The interval between the bag bodies 12 refers to the distance between the centers of the two bag bodies 12. The core thickness refers to the thickness along the stacking direction. In this arrangement, the spacing between the two bag bodies 12 is an integer multiple of the thickness of the core 21, and the two bag bodies 12 are both arranged in the R angle area, so that one or more cores 21 can be spaced between the two bag bodies 12.

[0055] The flame retardant released after the bag body 12 melts or breaks has a certain diffusion area, and the volume of the bag body 12 is limited by the size of the R angle area, and cannot accommodate too much flame retardant, resulting in the flame retardant in one bag body 12 may not be able to diffuse to the entire battery cell 20. When multiple bag bodies 12 are provided, there is a certain interval between the multiple bag bodies 12, which can ensure that the released flame retardant diffuses with the positions of the multiple bag bodies 12 as the center, increase the overall efficiency of the flame retardant release, make the flame retardant have a higher content in the battery cell 20 in a short time, and improve the flame retardant effect.

[0056] Continuing to refer to FIG. 1 , in some embodiments, the insulating film substrate 11 includes: a first film body 111, used to cover the first side surface S1, at least part of the second side surface S2 and at least part of the third side surface of the battery cell 20; the second side surface S2 and the third side surface are opposite; a second film body 112, used to cover the fourth side surface, at least part of the second side surface S2 and at least part of the third side surface of the battery cell 20; the fourth side surface is opposite to the first side surface S1; and a third film body 113, used to cover the bottom surface, at least part of the second side surface S2 and at least part of the third side surface of the battery cell 20, one side of the third film body 113 is connected to the first film body 111, and the other opposite side is connected to the second film body 112. Figure 5 As shown, Figure 5 FIG. 1 shows a three-dimensional diagram of a first film body 111 and a second film body 112 being wrapped in one embodiment, wherein Figure 5 The battery cell 20 is hidden.

[0057] The battery cell 20 is stacked by multiple winding cores 21 to form a square structure, including four side surfaces, a top surface and a bottom surface. Among them, the positive pole tabs and negative pole tabs of the multiple winding cores 21 are all located on the top surface of the battery cell 20. The first side S1 is opposite to the fourth side, and the second side S2 is opposite to the third side. In this embodiment, the arc edge of the winding core 21 is located on the second side S2 and the third side, that is, the R angle is located on the second side S2 and the third side.

[0058] The first film body 111 and the second film body 112 can be bent in the area used to cover the second side surface S2 and the third side surface of the battery cell 20, so that the first film body 111 and the second film body 112 cover the four sides of the battery cell 20. The third film body 113 can be bent in the area used to cover the second side surface S2 and the third side surface of the battery cell 20, so as to cover the bottom surface of the battery cell 20, at least part of the second side surface S2 and at least part of the third side surface, and the third film body 113 connects the first film body 111 and the second film body 112. In this way, the first film body 111, the second film body 112 and the third film body 113 form a containing structure with closed sides and bottom surfaces, which can protect the battery cell 20. Further, the top cover structure 30 is arranged on the top surface of the battery cell 20, and a hot melt point is arranged on the side of the top cover structure 30. The first film body 111 and the second film body 112 are bonded to the top cover structure 30 by hot melt adhesive at the hot melt point, and the battery cell 20 is sealed and protected, thereby improving the safety performance of the battery cell 20.

[0059] In some embodiments, the first film body 111 is provided with a bag body 12 for covering the second side surface S2 and the third side surface. In some embodiments, the second film body 112 is provided with a bag body 12 for covering the second side surface S2 and the third side surface. In this way, when the first film body 111 and the second film body 112 cover the second side surface S2 and the third side surface, the bag body 12 is just embedded in the R corner area of ​​the winding core 21.

[0060] In some embodiments, the width of the bag body 12 is less than 60 mm, and the thickness is less than 30 mm. The width and thickness of the bag body 12 can be determined according to the area size of the R angle, and the area size of the R angle is related to the thickness of the winding core 21, so the width and thickness of the bag body 12 are determined according to the thickness of the winding core 21. Schematically, as shown in Figure 3 As shown, the side of the core 21 is regarded as a semicircle, the thickness of the core 21 is the diameter, and the width of the bag body 12 should be less than the thickness of the core 21. In actual production, the thickness of the core 21 = the thickness of the battery cell 20 / the number of cores. Usually, the thickness of the core 21 is 5~60mm, so the width of the bag body 12 is less than 60mm. The gap between the R corners of the two cores 21 is conical. According to the thickness of the core 21, the height of the conical space is approximately 3mm~30mm. Therefore, the thickness of the bag body 12 is less than 30mm. The width of the bag body 12 is set to be less than 60mm, and the thickness is set to be less than 30mm. The bag body 12 can be set in the gap area between the R corners of the two cores 21.

[0061] See also Figure 4The present application also provides a battery, which includes: a battery cell 20, the battery cell 20 includes a plurality of stacked winding cores 21; an insulating film structure 10; a top cover structure 30, the top cover structure 30 is arranged on the top surface of the battery cell 20; a battery case, the battery case is a top opening structure, and the accommodating cavity formed is used to accommodate the battery cell 20 wrapped with the insulating film structure 10.

[0062] Among them, the battery can be a secondary battery, and the secondary battery can be a lithium-ion secondary battery or a sodium-ion secondary battery, etc. Optionally, the secondary battery includes a positive electrode sheet, a negative electrode sheet, an electrolyte and a separator. Among them, the positive electrode sheet, the negative electrode sheet and the separator can be made into a battery cell 20 by a winding process or a lamination process, and the insulating film structure 10 is coated on the outside of the battery cell 20. During the battery charging and discharging process, the active ions are embedded and removed back and forth between the positive electrode sheet and the negative electrode sheet. The electrolyte plays the role of conducting ions between the positive electrode sheet and the negative electrode sheet. The separator is arranged between the positive electrode sheet and the negative electrode sheet, which plays the role of preventing the positive and negative electrodes from short-circuiting, and at the same time allows ions to pass through.

[0063] The present application also provides an electric device, the electric device includes the above-mentioned battery, the battery is used as a power source of the electric device to store energy. Optionally, the electric device can be a smart terminal or an electric car, the smart terminal includes a mobile phone, a laptop computer, a tablet computer, etc., and the electric car includes a pure electric car and a hybrid electric car, etc.

[0064] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. An insulating film structure, characterized in that: Used to wrap a battery core, the battery core includes a plurality of stacked winding cores, and the insulating film structure includes: Insulating film substrate; More than one bag body, wherein a flame retardant is arranged inside the bag body, and the bag body is arranged on a side of the insulating film substrate for contacting the battery core.

2. The insulating film structure according to claim 1, characterized in that: When the insulating film substrate covers the battery core, the bag body is located in a space formed by the insulating film substrate and the R angle of the winding core.

3. The insulating film structure according to claim 1, characterized in that: The insulating film substrate comprises: A first film body is used to cover the first side surface, at least a portion of the second side surface and at least a portion of the third side surface of the battery cell; the second side surface is opposite to the third side surface; A second film body is used to cover a fourth side surface of the battery core, at least a portion of the second side surface, and at least a portion of the third side surface; the fourth side surface is opposite to the first side surface; and The third film body is used to cover the bottom surface, at least a part of the second side surface and at least a part of the third side surface of the battery cell. One side of the third film body is connected to the first film body, and the other opposite side is connected to the second film body.

4. The insulating film structure according to claim 3, characterized in that: The bag body is provided on a portion of the first film body used for covering the second side surface and a portion of the first film body used for covering the third side surface; and / or The bag body is provided on a portion of the second film body used for covering the second side surface and a portion of the second film body used for covering the third side surface.

5. The insulating film structure according to claim 1, characterized in that: The insulating film structure includes a plurality of bag bodies, and the plurality of bag bodies are arranged at intervals, wherein the interval distance between two bag bodies = (core thickness × n), where n is a positive integer.

6. The insulating film structure according to claim 1, characterized in that: The bag body has a width of less than 60 mm and a thickness of less than 30 mm.

7. The insulating film structure according to claim 1, characterized in that: The material of the bag body is one of polyethylene, polypropylene and polyethylene terephthalate.

8. The insulating film structure according to claim 1, characterized in that: The flame retardant is a phosphorus-containing flame retardant and / or a halogen-based flame retardant.

9. A battery, characterized in that: The battery comprises: A battery cell, comprising a plurality of stacked cores; The insulating film structure according to any one of claims 1 to 8; A top cover structure, arranged on the top surface of the battery cell; The battery shell is a top-open structure, and the accommodating cavity formed is used to accommodate the battery core wrapped with the insulating film structure.

10. An electrical device, characterized in that: The electrical device comprises the battery according to claim 9.

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