Insulating film, battery structure, and battery pack

Abstract

The utility model belongs to the technical field of batteries, and discloses an insulating film, a battery structure and a battery pack, the insulating film is used for wrapping a battery monomer and comprises a first diaphragm and a second diaphragm, the first diaphragm is provided with a first sealing area, the second diaphragm is attached to the first diaphragm, the second diaphragm is provided with a second sealing area, and the first sealing area and the second sealing area are arranged along the circumferential direction of the second sealing area. The edge of the second sealing area is in sealing connection with the edge of the first sealing area, so that an accommodating cavity is formed between the first sealing area and the second sealing area, the accommodating cavity is filled with a cooling flame-retardant medium, and the insulating film can realize cooling and flame-retardant effects on the battery monomers.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to an insulating film, battery structure and battery pack. BACKGROUND

[0002] The battery pack is a kind of battery system combined by several battery monomers, mainly used to store and supply electric energy, and is widely used in electric vehicles, unmanned aerial vehicles and other products.

[0003] In order to increase the insulation performance between adjacent battery monomers, generally, insulating film is coated outside battery monomer, and the commonly used insulating film only has insulation performance, if the cooling and flame-retardant effects of battery monomer are realized, cooling device and flame-retardant plate need to be additionally arranged in battery pack, and the structure design increases the volume of battery pack, which is not conducive to improving the energy density of battery pack.

[0004] Therefore, an insulating film, battery structure and battery pack are needed to solve the above technical problems. UTILITY MODEL CONTENTS

[0005] The first purpose of the utility model is to provide an insulating film, which can realize the cooling and flame-retardant effects of battery monomer.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] The insulating film is used for coating battery monomer, comprising:

[0008] The first film sheet is provided with a first sealing area;

[0009] The second film sheet is attached to the first film sheet, and the second film sheet is provided with a second sealing area, the edge of the second sealing area is sealingly connected with the edge of the first sealing area along the circumferential direction of the second sealing area, so as to form a containing cavity between the second sealing area and the first sealing area, and the containing cavity is filled with cooling and flame-retardant medium.

[0010] Optionally, the first film sheet is further provided with a plurality of first sealing parts, and the plurality of first sealing parts are located in the first sealing area, the second film sheet is further provided with a plurality of second sealing parts, and the plurality of second sealing parts are located in the second sealing area, each second sealing part is sealingly connected with a corresponding first sealing part, so as to form a plurality of sub-cavities in the containing cavity, and each sub-cavity is filled with cooling and flame-retardant medium.

[0011] Optionally, the plurality of first sealing parts are in grid shape in the first sealing area, and the plurality of second sealing parts are in grid shape in the second sealing area, so that the plurality of sub-cavities are in grid shape.

[0012] Optionally, the first sealing area and the second sealing area are both at least two in number and one-to-one corresponding to form at least two accommodating cavities.

[0013] The second purpose of the utility model lies in providing a battery structure, the insulating film of the battery structure can cool and flame retardant the battery monomer.

[0014] To achieve the purpose, the utility model adopts the following technical scheme:

[0015] The battery structure comprises a battery monomer and the insulating film, and the insulating film is wrapped on the outer wall of the battery monomer.

[0016] Optionally, the outer wall comprises two oppositely arranged first outer walls, two oppositely arranged second outer walls and two oppositely arranged third outer walls, the two second outer walls and the two third outer walls are cross arranged and sequentially connected in a head-to-tail mode, and the two second outer walls and the two third outer walls are connected with the two first outer walls;

[0017] The insulating film is provided with a first wrapping area, a second wrapping area, a third wrapping area, a fourth wrapping area and a fifth wrapping area, and the number of the second wrapping area is two.

[0018] The first wrapping area and the third wrapping area are wrapped on the corresponding first outer wall respectively, the two second wrapping areas are wrapped on the corresponding second outer wall respectively, and the fourth wrapping area and the fifth wrapping area are wrapped on the corresponding second outer wall respectively.

[0019] Optionally, the two sides of the third wrapping area opposite in the first direction are connected with the corresponding second wrapping area respectively, one side of at least one of the two second wrapping areas away from the third wrapping area is connected with the first wrapping area, one side of at least one of the two second wrapping areas in the second direction is connected with the fourth wrapping area, the other side of at least one of the two second wrapping areas in the second direction is connected with the fifth wrapping area, and the second direction is perpendicular to the first direction.

[0020] Optionally, at least one of the two first outer walls is provided with a conductive terminal, and the fourth wrapping area, the fifth wrapping area and at least one of the two second wrapping areas are provided with an accommodating cavity.

[0021] The third purpose of the utility model lies in providing a battery pack, and the battery pack has higher energy density.

[0022] To achieve the purpose, the utility model adopts the following technical scheme:

[0023] The battery pack comprises at least two battery structures.

[0024] Optionally, the at least two battery structures are sequentially arranged along the same direction, and the insulating film on one side of the two adjacent battery structures facing each other is provided with an accommodating cavity.

[0025] The utility model discloses a beneficial effect:

[0026] The utility model provides a kind of insulation film, which includes first membrane and second membrane, first sealing area on the first membrane is sealed with the second sealing area on the second membrane Connection, to form containing cavity between first sealing area and second sealing area, containing cavity is filled with cooling fire-retardant medium, to form cooling fire-retardant bag on insulation film, the insulation film is covered on the outer wall of battery monomer, cooling fire-retardant medium can absorb the heat of battery monomer, realize the heat dissipation effect to battery monomer, in addition, when battery monomer thermal runaway or life is close, battery monomer expands, multiple battery monomers are extruded each other, or, battery monomer and other objects (for example the inner wall of battery box) extrusion occurs, to make cooling fire-retardant bag rupture, cooling fire-retardant medium in cooling fire-retardant bag spills to reach fire-retardant effect. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is the partial enlarged sectional structure schematic diagram of cooling fire-retardant bag provided by the utility model embodiment;

[0028] Figure 2 It is the structure schematic diagram of insulation film provided by the utility model embodiment;

[0029] Figure 3 It is the main preparation flow chart of cooling fire-retardant bag provided by the utility model embodiment;

[0030] Figure 4 It is the structure schematic diagram of battery monomer provided by the utility model embodiment;

[0031] Figure 5 It is the structure schematic diagram of battery structure provided by the utility model embodiment;

[0032] Figure 6 It is the first structure schematic diagram when the insulation film of the utility model embodiment covers battery monomer;

[0033] Figure 7 It is the second structure schematic diagram when the insulation film of the utility model embodiment covers battery monomer;

[0034] Figure 8 It is the third structure schematic diagram when the insulation film of the utility model embodiment covers battery monomer;

[0035] Figure 9 It is the fourth structure schematic diagram when the insulation film of the utility model embodiment covers battery monomer;

[0036] Figure 10 It is the structure schematic diagram of battery structure provided by another embodiment of the utility model.

[0037] Figure 11 is a structural diagram of a battery structure provided by another embodiment of the utility model;

[0038] Figure 12 is an explosion structural diagram of a battery pack provided by an embodiment of the utility model.

[0039] In the figure,

[0040] 1, insulating film;11, first diaphragm;111, first sealing portion;12, second diaphragm;121, second sealing portion;13, containing cavity;131, sub-containing cavity;14, cooling fire -retardant medium;151, first cladding area;152, second cladding area;153, third cladding area;1531, avoid hole;154, fourth cladding area;155, fifth cladding area;156, first avoid area;157, second avoid area;16, cooling fire -retardant bag;

[0041] 2, battery monomer;21, first outer wall;22, second outer wall;23, third outer wall;24, conductive terminal;

[0042] 3, battery structure;

[0043] D1, first direction;D2, second direction. Specific implementation

[0044] The utility model will be further explained in detail in combination with the drawings and embodiments.It can be understood that the specific embodiments described here are only used to explain the utility model, and not limit the utility model.In addition, it needs to be explained that, for the convenience of description, only the part related to the utility model is shown in the drawings, not all structures.

[0045] In the description of the utility model, unless another explicit provision and limitation, the terms "connect", "connect", "fix" should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integral;Can be mechanical connection, can also be electrical connection;Can be directly connected, can also be indirectly connected through intermediate medium, can be the communication of two elements or the interaction of two elements.For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0048] This embodiment provides an insulating film for covering battery cells, which can achieve cooling and flame-retardant effects on the battery cells.

[0049] Specifically, such as Figure 1 As shown, the insulating film 1 includes a first film 11 and a second film 12. The first film 11 has a first sealing area (not shown in the figure), and the second film 12 is attached to the first film 11. The second film 12 has a second sealing area (not shown in the figure). Along the circumference of the second sealing area, the edge of the second sealing area is sealed to the edge of the first sealing area, so that a receiving cavity 13 is formed between the second sealing area and the first sealing area. The receiving cavity 13 is filled with a cooling flame retardant medium 14.

[0050] The insulating film 1 includes a first film 11 and a second film 12 that are bonded together. A first sealing area on the first film 11 and a second sealing area on the second film 12 are sealed together to form a receiving cavity 13 between the first sealing area and the second sealing area. The receiving cavity 13 is filled with a cooling flame-retardant medium 14 to form a cooling flame-retardant bag 16 on the insulating film 1 (e.g., Figure 2As shown, the inner space of the cooling and fire-retardant bag 16, i.e., the accommodating cavity 13, is used to wrap the insulating film 1 on the outer wall of the battery monomer 2. The cooling and fire-retardant medium 14 can absorb the heat of the battery monomer 2, thereby achieving the heat dissipation effect of the battery monomer 2. In addition, when the battery monomer 2 is in thermal runaway or is close to the end of its life, the battery monomer 2 expands and is pressed by other battery monomers 2 or other objects (e.g., the inner wall of the battery box), so that the cooling and fire-retardant bag 16 is broken, and the cooling and fire-retardant medium 14 in the cooling and fire-retardant bag 16 spills out to achieve the fire-retardant effect.

[0051] It should be noted that the cooling and fire-retardant medium 14 can be a liquid, a gel, a solid-liquid mixture, or a solid-gel mixture. In addition, the cooling and fire-retardant medium 14 can be water, dimethylsiloxane, and fluorinated liquid, which are common in the art and have both cooling and fire-retardant effects. Here, they are not listed one by one.

[0052] Optionally, after the insulating film 1 is wrapped on the outer wall of the battery monomer 2, the cooling and fire-retardant medium 14 will gather at the bottom of the accommodating cavity 13 under the action of gravity, thereby easily causing the problem of uneven cooling of the outer wall of the battery monomer 2. To solve this technical problem, as shown in Figure 1 and Figure 2 As shown, the first film 11 is further provided with a plurality of first sealing portions 111, and the plurality of first sealing portions 111 are located in the first sealing area. The second film 12 is further provided with a plurality of second sealing portions 121, and the plurality of second sealing portions 121 are located in the second sealing area. Each second sealing portion 121 is sealingly connected with a corresponding first sealing portion 111 to form a plurality of sub-accommodating cavities 131 in the accommodating cavity 13. Each sub-accommodating cavity 131 is filled with the cooling and fire-retardant medium 14. Since the plurality of sub-accommodating cavities 131 are not connected with each other, the cooling and fire-retardant medium 14 can only gather at the bottom of each sub-accommodating cavity 131 under the action of gravity, and cannot flow between adjacent sub-accommodating cavities 131. The uniformity of the distribution of the cooling and fire-retardant medium 14 in the accommodating cavity 13 is improved, thereby improving the uniformity of the cooling of the outer wall of the battery monomer 2.

[0053] It should be noted that the plurality of first sealing portions 111 and the plurality of second sealing portions 121 can be various shapes, for example, the plurality of first sealing portions 111 and the plurality of second sealing portions 121 are both circular, at this time the plurality of sub-cavities 131 are mutually independent circular structures. The plurality of first sealing portions 111 and the plurality of second sealing portions 121 can also be both wavy or parallel straight lines, and then the plurality of sub-cavities 131 are roughly strip-shaped structures, at this time, when the insulating film 1 is attached to the outer wall of the battery monomer 2, the placement direction of the battery monomer 2 needs to be considered to ensure that the plurality of first sealing portions 111 and the plurality of second sealing portions 121 are horizontally arranged, thereby making the plurality of sub-cavities 131 extend in the horizontal direction, thereby avoiding the accumulation of the cooling and flame-retardant medium 14 at the bottom of the cavity 13.

[0054] As shown in Figure 1 and Figure 2 In the embodiment, the plurality of first sealing portions 111 are in a grid shape in the first sealing area, and the plurality of second sealing portions 121 are in a grid shape in the second sealing area, thereby making the plurality of sub-cavities 131 have a grid structure. This structure design increases the limiting direction of the flow of the cooling and flame-retardant medium 14 in the sub-cavity 131. When the insulating film 1 is attached to the outer wall of the battery monomer 2, the placement direction of the battery monomer 2 does not need to be considered to avoid the problem of the accumulation of the cooling and flame-retardant medium 14 at the bottom of the cavity 13. Moreover, when the battery monomer 2 shakes or the like, the cooling and flame-retardant medium 14 in adjacent two sub-cavities 131 in the same horizontal direction will not flow into each other, which has the effect of further improving the uniformity of the distribution of the cooling and flame-retardant medium 14 in the cavity 13.

[0055] Further, the plurality of sub-cavities 131 have the same volume, and the cooling and flame-retardant medium 14 in the plurality of sub-cavities 131 has the same filling amount, which further improves the uniformity of the distribution of the cooling and flame-retardant medium 14 in the cavity 13, thereby further improving the uniformity of the cooling of the side wall of the battery monomer 2.

[0056] Optionally, the number of the first sealing area and the second sealing area is at least two and one-to-one corresponding, to form at least two cavities 13, that is, at least two cooling and flame-retardant bags 16 are formed on the insulating film 1. For example, the number of the first sealing area, the second sealing area and the cavity 13 can be two, three, five, etc. In the embodiment, the first sealing area, the second sealing area and the cavity 13 are all two, that is, two cooling and flame-retardant bags 16 are formed on the insulating film 1, and the two cooling and flame-retardant bags 16 correspond to two different outer walls of the battery monomer 2 respectively. It can be understood that in other embodiments, the at least two cooling and flame-retardant bags 16 can correspond to different outer walls of the battery monomer 2 respectively, or can all correspond to the same outer wall of the battery monomer 2, or part of the cooling and flame-retardant bags 16 can correspond to different outer walls of the battery monomer 2, and part of the cooling and flame-retardant bags 16 can correspond to the same outer wall of the battery monomer 2.

[0057] Optionally, one side of one of the first film sheet 11 and the second film sheet 12, which is away from the other, is provided with a glue layer (not shown in the figure), and the insulation film 1 is pasted on the outer wall of the battery monomer 2 through the glue layer.

[0058] Figure 3 When the insulation film 1 is provided with one cooling and flame-retardant bag 16 (i.e., the insulation film 1 is provided with one containing cavity 13), the main preparation process of the insulation film 1 is as follows: providing the first film sheet 11; ion-modifying the surface of the first sealing area of the first film sheet 11, so that the cooling and flame-retardant medium 14 can be more uniformly distributed in the first sealing area; filling the cooling and flame-retardant medium 14 into the surface of the first sealing area; attaching the second film sheet 12 on the first film sheet 11, and sealing and connecting the edges of the second sealing area and the edges of the first sealing area through heat pressing or the like, so as to form the containing cavity 13 between the second sealing area and the second sealing area, and the cooling and flame-retardant medium 14 is located in the containing cavity 13; heat pressing the second film sheet 12 by using a grid-shaped mold, so as to separate the containing cavity 13 into a plurality of mutually disconnected sub-containing cavities 131, the plurality of sub-containing cavities 131 are roughly grid-shaped, and each of the sub-containing cavities 131 is provided with the cooling and flame-retardant medium 14, thereby forming one piece of insulation film with one cooling and flame-retardant bag 16.

[0059] It should be noted that the specific way of ion-modifying the surface of the first sealing area is a prior art known in the art, which will not be described here.

[0060] It should be further noted that in another embodiment, the part of the edges of the second sealing area and the part of the edges of the first sealing area can be first sealed and connected, so as to form an open cavity between the first film sheet 11 and the second film sheet 12, then the cooling and flame-retardant medium 14 is filled into the open cavity, and after the filling is completed, the opening of the open cavity is heat-pressed and sealed, so as to form one sealed cooling and flame-retardant bag 16.

[0061] The embodiment also provides a battery structure 3, and the insulation film 1 of the battery structure 3 can cool and flame-retardant the battery monomer 2.

[0062] Specifically, the battery structure 3 comprises the battery monomer 2 and the above-mentioned insulation film 1, and the insulation film 1 is wrapped on the outer wall of the battery monomer 2, so that the cooling and flame-retardant medium 14 in the cooling and flame-retardant bag 16 can absorb the heat of the battery monomer 2, so as to achieve the heat dissipation effect of the battery monomer 2, and in addition, when the battery monomer 2 is out of control or is close to the end of life, the battery monomer 2 expands, the plurality of battery monomers 2 press each other, or the battery monomer 2 is pressed with other objects (such as the inner wall of the battery box) in the outside world, so that the cooling and flame-retardant bag 16 is broken, and the cooling and flame-retardant medium 14 in the cooling and flame-retardant bag 16 is overflowed to achieve the flame-retardant effect.

[0063] In the prior art, when the battery monomer is coated with an insulating film, the insulating film is usually first coated on the side wall and the bottom wall of the battery monomer, and finally an insulating sheet is attached to the top wall of the battery monomer. This two-time coating structure design makes the coating process very cumbersome, and the insulating film and the insulating sheet need to be produced separately, which reduces the production efficiency and increases the production cost. To solve this technical problem, as shown in Figure 2 、 Figure 4 and Figure 5 In the present embodiment, the outer wall of the battery monomer 2 includes two oppositely arranged first outer walls 21, two oppositely arranged second outer walls 22, and two oppositely arranged third outer walls 23. The two second outer walls 22 and the two third outer walls 23 are crosswise arranged and sequentially connected end to end. The two second outer walls 22 and the two third outer walls 23 are both connected to the two first outer walls 21. The insulating film 1 is provided with a first coating area 151, a second coating area 152, a third coating area 153, a fourth coating area 154, and a fifth coating area 155. The number of the second coating areas 152 is two. The first coating area 151 and the third coating area 153 are respectively coated on a corresponding one of the first outer walls 21. The two second coating areas 152 are respectively coated on a corresponding one of the second outer walls 22. The fourth coating area 154 and the fifth coating area 155 are respectively coated on a corresponding one of the second outer walls 22. Thus, the entire outer wall of the battery monomer 2 can be coated with one piece of insulating film 1, eliminating the insulating sheet structure and the process of separately preparing the insulating sheet. Furthermore, the battery monomer 2 is coated once with one piece of insulating film 1, eliminating the two-time coating structure design, greatly improving the production efficiency and reducing the production cost.

[0064] Further, as shown in Figure 2 The opposite sides of the third coating area 153 in the first direction D1 are respectively connected to a corresponding one of the second coating areas 152. The first coating area 151, the fourth coating area 154, and the fifth coating area 155 are all two. The side of each second coating area 152 away from the third coating area 153 is respectively connected to a corresponding one of the first coating areas 151. One side of each second coating area 152 in the second direction D2 is respectively connected to a corresponding one of the fourth coating areas 154. The other side of each second coating area 152 in the second direction D2 is respectively connected to a corresponding one of the fifth coating areas 155. The second direction D2 is perpendicular to the first direction D1. Thus, the two first coating areas 151 are coated on the same first outer wall 21, the third coating area 153 is coated on the other first outer wall 21, the two fourth coating areas 154 are coated on the same third outer wall 23, and the two fifth coating areas 155 are coated on the other third outer wall 23. This structure design makes the overall area of the insulating film 1 more evenly distributed, which is conducive to reducing the coating difficulty of the insulating film 1 on the battery monomer 2, and can ensure that the edges of the battery monomer 2 are coated inside the insulating film 1.

[0065] In other embodiments, the number of the first covering regions 151 is one, one of the two second covering regions 152 is connected to the first covering region 151 on one side of the third covering region 153, and the first covering region 151 covers one of the first outer walls 21 alone, and the other first outer wall 21 is covered by the third covering region 153.

[0066] In other embodiments, the number of the fourth covering regions 154 is one, the number of the fifth covering regions 155 is one, and one of the second outer walls 22 is covered by the fourth covering region 154 alone, and the other second outer wall 22 is covered by the fifth covering region 155 alone. It should be noted that when the number of the fourth covering regions 154 and the fifth covering regions 155 is one, the fourth covering region 154 and the fifth covering region 155 can be connected to the two opposite sides of the same second covering region 152 in the second direction D2, or the fourth covering region 154 can be connected to one side of one second covering region 152 in the second direction D2, and the fifth covering region 155 can be connected to the other side of the other second covering region 152 in the second direction D2.

[0067] In other embodiments, the number of the fourth covering regions 154 is two, and the number of the fifth covering regions 155 is one, and the two fourth covering regions 154 cover the same second outer wall 22, and the other second outer wall 22 is covered by the fifth covering region 155 alone.

[0068] In other embodiments, the number of the fourth covering regions 154 is one, and the number of the fifth covering regions 155 is two, and one second outer wall 22 is covered by the fourth covering region 154 alone, and the two fifth covering regions 155 cover the other second outer wall 22 together.

[0069] Optionally, at least one of the two first outer walls 21 is provided with a conductive terminal 24, and at least one of the fourth covering region 154, the fifth covering region 155, and the two second covering regions 152 is provided with a receiving cavity 13, that is, at least one of the fourth covering region 154, the fifth covering region 155, and the two second covering regions 152 is provided with a cooling and flame-retardant bag 16. When the insulating film 1 is prepared, a clearance hole 1531 needs to be formed on the third covering region 153 and / or the first covering region 151 to avoid the conductive terminal 24, and the receiving cavity 13 is arranged at at least one of the fourth covering region 154, the fifth covering region 155, and the two second covering regions 152. When the insulating film 1 is produced, no clearance needs to be considered between the receiving cavity 13 and the clearance hole 1531, which reduces the production difficulty and is also beneficial to expand the volume of the receiving cavity 13, thereby increasing the filling amount of the cooling and flame-retardant medium 14 in the receiving cavity 13.

[0070] In addition, when the conductive terminals 24 are protruded on only one first outer wall 21 (for example, in the embodiment, both of the conductive terminals 24 are protruded on the same first outer wall 21), generally, the cooling device such as the liquid cooling plate is attached to the other first outer wall 21 to cool the battery monomer 2, but generally, the area of the first outer wall 21 is smaller, and the areas of the second outer wall 22 and the third outer wall 23 are both larger than the area of the first outer wall 21, and the structure of attaching the cooling device such as the liquid cooling plate to the first outer wall 21 reduces the cooling efficiency of the battery monomer 2. In the technical scheme provided in the embodiment, at least one of the fourth covering area 154, the fifth covering area 155, and the two second covering areas 152 is provided with the cooling fire-retardant bag 16, which expands the cooling area of the battery monomer 2 and is beneficial to improve the cooling efficiency of the battery monomer 2.

[0071] In the embodiment, the number of the accommodating cavities 13 is two, and the two accommodating cavities 13 are respectively located in the corresponding one second covering area 152, so that the two cooling fire-retardant bags 16 are respectively corresponding to one second outer wall 22, to improve the cooling efficiency of the battery monomer 2.

[0072] Further, the area of the second outer wall 22 is larger than the area of the third outer wall 23, that is, the second outer wall 22 is the outer wall with the largest area, the volume of the accommodating cavity 13 is expanded as much as possible, and then the filling amount of the cooling fire-retardant medium 14 can be improved, which is beneficial to further improve the cooling efficiency of the battery monomer 2.

[0073] In other embodiments, the fourth covering area 154 and / or the fifth covering area 155 can be provided with the accommodating cavity 13, and one of the two second covering areas 152 can also be provided with the accommodating cavity 13, which can be determined according to actual needs, and here is not listed one by one.

[0074] When the outer wall of the battery monomer 2 is covered with the insulating film 1, as shown in Figure 2 and Figure 6 , the insulating film 1 is laid on a plane, and the upper surface of the insulating film 1 is glued (the glue layer is not shown), the first outer wall 21 protruded with the conductive terminal 24 is set upward, and the other first outer wall 21 is erected on one first covering area 151, so that the first covering area 151 is pasted on the lower first outer wall 21.

[0075] As shown in Figure 2 , Figure 4 and Figure 7 , the position of the battery monomer 2 is kept unchanged, and the part of the insulating film 1 not pressed by the battery monomer 2 is pulled upward, so that one second covering area 152 is pasted on one second outer wall 22.

[0076] As shown in Figure 2 and Figure 8As shown, the insulating film 1 is bent around the outer periphery of the battery monomer 2, the conductive terminal 24 is passed through the avoiding hole 1531 on the third covering area 153, and the third covering area 153 is adhered to the first outer wall 21 with the conductive terminal 24, and the other second covering area 152 is adhered to the other second outer wall 22.

[0077] As shown in Figure 2 and Figure 9 , the insulating film 1 is bent, and the other first covering area 151 is adhered to the lower first outer wall 21, at this time, the two second covering areas 152 are respectively covered on the corresponding second outer wall 22, the third covering area 153 is covered on the upper first outer wall 21, the two first covering areas 151 are covered on the lower first outer wall 21, and the two third outer walls 23 are not covered by the insulating film 1.

[0078] As shown in Figure 2 , in the second direction D2, the opposite sides of the third covering area 153 are respectively connected with a first avoiding area 156, and one of the first avoiding areas 156 is respectively connected with a corresponding fourth covering area 154 on the opposite sides in the first direction D1, and the other first avoiding area 156 is respectively connected with a corresponding fifth covering area 155 on the opposite sides in the first direction D1; each of the four corners of the insulating film 1 has a second avoiding area 157.

[0079] As shown in Figure 2 , Figure 5 and Figure 9As shown, after the two first outer walls 21 and the two second outer walls 22 are completely wrapped, one first avoiding area 156 is cut off (alternatively, the first avoiding area 156 is cut open at the joint with the two fifth wrapping areas 155, and the first avoiding area 156 is folded along the joint with the third wrapping area 153. Alternatively, the first avoiding area 156 is cut open at the joint with the first fifth wrapping area 155, the first avoiding area 156 is cut open at the joint with the third wrapping area 153, and the first avoiding area 156 is folded along the joint with the other fifth wrapping area 155). The other first avoiding area 156 is cut off (alternatively, the first avoiding area 156 is cut open at the joint with the two fourth wrapping areas 154, and the first avoiding area 156 is folded along the joint with the third wrapping area 153. Alternatively, the first avoiding area 156 is cut open at the joint with one fourth wrapping area 154, the first avoiding area 156 is cut open at the joint with the third wrapping area 153, and the first avoiding area 156 is folded along the joint with the other fourth wrapping area 154). Then, the four second avoiding areas 157 are cut off (alternatively, for the second avoiding area 157 connected between the fourth wrapping area 154 and the first wrapping area 151, one of the joints of the second avoiding area 157 with the fourth wrapping area 154 and the first wrapping area 151 is cut open, and the other is folded. For the second avoiding area 157 connected between the fifth wrapping area 155 and the first wrapping area 151, one of the joints of the second avoiding area 157 with the fifth wrapping area 155 and the first wrapping area 151 is cut open, and the other is folded. Alternatively, for the second avoiding area 157 connected between the fourth wrapping area 154 and the first wrapping area 151, the second avoiding area 157 is cut into two parts, one of which is folded along the joint with the first wrapping area 151, and the other is folded along the joint with the fourth wrapping area 154. For the second avoiding area 157 connected between the fifth wrapping area 155 and the first wrapping area 151, the second avoiding area 157 is cut into two parts, one of which is folded along the joint with the first wrapping area 151, and the other is folded along the joint with the fifth wrapping area 155). Then, the two fourth wrapping areas 154 are folded so that both of them are pasted on the same third outer wall 23, and in the embodiment, the two fourth wrapping areas 154 are arranged in overlap on the same third outer wall 23 to ensure that all surfaces of the third outer wall 23 are wrapped. The two fifth wrapping areas 155 are folded so that both of them are pasted on another third outer wall 23, and in the embodiment, the two fifth wrapping areas 155 are arranged in overlap on the third outer wall 23 to ensure that all surfaces of the third outer wall 23 are wrapped. It is particularly pointed out that the wrapping method of the insulating film in the present application is not limited to the above method, and the above wrapping method is only illustrative.

[0080] In another embodiment, after both fourth covering areas 154 are adhered to the same third outer wall 23, the two fourth covering areas 154 are spaced apart. At this time, a portion of the third outer wall 23 corresponding to the fourth covering area 154 is not covered with the insulating film 1. After both fifth covering areas 155 are adhered to another third outer wall 23, the two fifth covering areas 155 are spaced apart. At this time, a portion of the third outer wall 23 corresponding to the fifth covering area 155 is not covered with the insulating film 1. Figure 10 This is a schematic diagram of battery structure 3 in this embodiment.

[0081] In another embodiment, two fourth covering regions 154 are joined together and adhered to the same third outer wall 23. In this case, the entire third outer wall 23 corresponding to the fourth covering region 154 is covered with insulating film 1. Similarly, two fifth covering regions 155 are joined together and adhered to another third outer wall 23. In this case, the entire third outer wall 23 corresponding to the fifth covering region 155 is covered with insulating film 1. Figure 11 This is a schematic diagram of battery structure 3 in this embodiment.

[0082] This embodiment also provides a battery pack with a high energy density.

[0083] Specifically, the battery pack includes at least two of the aforementioned battery structures 3. In this battery pack, the battery cells 2 of the battery structures 3 are electrically connected. This battery pack eliminates the need for a flame-retardant plate sandwiched between adjacent battery cells 2, reducing the overall volume of the battery pack and thus increasing its energy density. Furthermore, the insulating film 1 covering the outer wall of the battery cell 2 has a receiving cavity 13 filled with a cooling flame-retardant medium 14, which cools the battery cell 2. This eliminates the need for a cooling device or reduces its size, further improving the energy density of the battery pack.

[0084] Optionally, such as Figure 12 As shown, at least two battery structures 3 are arranged sequentially in the same direction. The insulating film 1 of the two adjacent battery structures 3 facing each other is provided with a receiving cavity 13. That is, after the battery is assembled, two cooling flame retardant bags 16 are sandwiched between two adjacent battery cells 2. When the battery cell 2 expands to a certain thickness, the two adjacent battery cells 2 squeeze each other, causing the cooling flame retardant bag 16 to rupture. The cooling flame retardant medium 14 inside the cooling flame retardant bag 16 overflows to achieve a good flame retardant effect.

[0085] It should be noted that when assembling batteries, attention should be paid to the compressive force between two adjacent battery structures 3 to avoid the problem of the cooling flame retardant bag 16 breaking during assembly.

[0086] Optionally, the two adjacent battery structures 3 are bonded and fixed to improve the connecting strength between the two adjacent battery structures 3, and further improve the overall structural strength of the battery pack.

[0087] Obviously, the above embodiments of the present application are merely examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. For those skilled in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present application. Here, it is not necessary and impossible to enumerate all the embodiments. Any modification, equivalent substitution and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application claims.

Claims

1. An insulating film for covering a battery cell (2), characterized by, The application relates to an insulation film (1) for a battery cell (2). The insulation film (1) comprises a first film sheet (11) provided with a first sealing area, and a second film sheet (12) attached to the first film sheet (11) and provided with a second sealing area. The edge of the second sealing area is sealingly connected with the edge of the first sealing area along the circumferential direction of the second sealing area, so that a containing cavity (13) is formed between the second sealing area and the first sealing area, and the containing cavity (13) is filled with a cooling and flame-retardant medium (14).

2. The insulating film according to claim 1, characterized by The first film sheet (11) is further provided with a plurality of first sealing portions (111), and the second film sheet (12) is further provided with a plurality of second sealing portions (121).

3. The insulating film according to claim 2, characterized by Each of the second sealing portions (121) is sealingly connected with a corresponding one of the first sealing portions (111) to form a plurality of sub-containing cavities (131) in the containing cavity (13), and each of the sub-containing cavities (131) is filled with the cooling and flame-retardant medium (14).

4. The insulating film according to any one of claims 1 to 3, characterized by The plurality of first sealing portions (111) are arranged in a grid shape in the first sealing area, and the plurality of second sealing portions (121) are arranged in a grid shape in the second sealing area, so that the plurality of sub-containing cavities (131) are arranged in a grid shape.

5. A battery structure characterized by The number of the first sealing areas and the second sealing areas is at least two and one-to-one corresponding, so as to form at least two containing cavities (13).

6. The battery structure of claim 5, wherein, The application further relates to a battery cell (2) comprising the insulation film (1) according to any one of claims 1-4, and the insulation film (1) is wrapped on the outer wall of the battery cell (2). The outer wall comprises two oppositely arranged first outer walls (21), two oppositely arranged second outer walls (22) and two oppositely arranged third outer walls (23), the two second outer walls (22) and the two third outer walls (23) are cross arranged and sequentially connected end to end, and the two second outer walls (22) and the two third outer walls (23) are connected with the two first outer walls (21). The insulation film (1) is provided with a first wrapping area (151), a second wrapping area (152), a third wrapping area (153), a fourth wrapping area (154) and a fifth wrapping area (155), and the number of the second wrapping areas (152) is two. The first wrapping area (151) and the third wrapping area (153) are wrapped on a corresponding one of the first outer walls (21), the two second wrapping areas (152) are wrapped on a corresponding one of the second outer walls (22), and the fourth wrapping area (154) and the fifth wrapping area (155) are wrapped on a corresponding one of the second outer walls (22).

7. The battery structure of claim 6, wherein The third cladding area (153) is connected with a corresponding one of the second cladding areas (152) on opposite sides in the first direction (D1), at least one of the two second cladding areas (152) is connected with a first cladding area (151) on a side away from the third cladding area (153), at least one of the two second cladding areas (152) is connected with a fourth cladding area (154) on a side in the second direction (D2), at least one of the two second cladding areas (152) is connected with a fifth cladding area (155) on another side in the second direction (D2), and the second direction (D2) is perpendicular to the first direction (D1).

8. The battery structure of claim 6, wherein At least one of the two first outer walls (21) is provided with a conductive terminal (24), and the fourth cladding area (154), the fifth cladding area (155), and at least one of the two second cladding areas (152) are provided with the accommodation cavity (13).

9. A battery pack characterized by The battery structure (3) according to any one of claims 5-8.

10. The battery pack of claim 9, wherein, At least two battery structures (3) are arranged in sequence in the same direction, and the accommodation cavity (13) is arranged on the insulating film (1) on a side facing each other of adjacent two battery structures (3).

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