Insulating film for battery cell and battery cell

Abstract

The utility model discloses an insulating film for a battery monomer and the battery monomer, and relates to the technical field of batteries, the insulating film for the battery monomer comprises an insulating film main body, the insulating film main body is annular so as to define an installation space for installing an electrode assembly of the battery monomer, the insulating film main body is provided with a first insulating film wall part, the first insulating film wall part is used for corresponding to a welding area of a shell of a battery monomer, and the protective layer is arranged on the outer surface of the first insulating film wall part. Therefore, the protective layer is arranged on the outer surface of the first insulating film wall part, so that the risk that the insulating film is scratched by a welding seam of a welding area of the shell can be reduced, the short-circuit risk of the battery monomer can be reduced, the safety and reliability of the battery monomer can be further improved, and the protective layer is small in occupied space, simple in arrangement method and convenient to popularize. And the assembly difficulty and the manufacturing cost of the battery monomer can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially is related to a kind of insulating film and battery monomer for battery monomer. BACKGROUND

[0002] In the related art, the insulation between the electrode assembly and the shell of the battery monomer is ensured by the insulating film inside the battery monomer. However, the insulating film is easily scratched by the weld seam of the shell, causing internal short circuit of the battery monomer. In the prior art, to prevent the insulating film from being scratched by the weld seam of the shell, a side plate is arranged between the weld seam and the insulating film to separate the weld seam and the insulating film, so as to avoid the insulating film being scratched by the weld seam of the shell, causing internal short circuit of the battery monomer. However, the side plate is a separate component, which increases the assembly difficulty and manufacturing cost of the battery monomer, and also reduces the space utilization inside the battery cell. SUMMARY

[0003] The utility model aims at at least one of the technical problems existing in the prior art. Therefore, one object of the utility model is to provide an insulating film for a battery monomer, which can ensure the insulation between the electrode assembly and the shell of the battery monomer, and protect the insulating film by the protective layer to reduce the risk of the insulating film being scratched by the weld seam of the welding area of the shell, thereby improving the safety and reliability of the battery monomer. In addition, the protective layer occupies a small space and is simple to set, which can reduce the assembly difficulty and manufacturing cost of the battery monomer.

[0004] The utility model further provides a battery monomer with the above insulating film.

[0005] The insulating film for a battery monomer according to the utility model embodiment comprises: an insulating film body, which is annular to define an installation space for installing an electrode assembly of a battery monomer, and has a first insulating film wall part corresponding to a welding area of a shell of the battery monomer; and a protective layer arranged on an outer surface of the first insulating film wall part.

[0006] The insulating film for a battery monomer according to the utility model embodiment is annular to define an installation space for installing an electrode assembly of a battery monomer, which can ensure the insulation between the electrode assembly and the shell of the battery monomer to prevent short circuit of the electrode assembly. The insulating film body has a first insulating film wall part corresponding to a welding area of a shell of the battery monomer, and a protective layer is arranged on an outer surface of the first insulating film wall part. The protective layer can protect the insulating film to reduce the risk of the insulating film being scratched by the weld seam of the welding area of the shell, thereby reducing the risk of short circuit of the battery monomer, improving the safety and reliability of the battery monomer, and reducing the assembly difficulty and manufacturing cost of the battery monomer due to the small space occupied by the protective layer and the simple setting method.

[0007] According to some embodiments of the present application, the thickness of the protective layer is greater than or equal to 0.2mm.

[0008] According to some embodiments of the present application, the insulation film body further has a plurality of second insulation film wall portions, the first insulation film wall portion and the plurality of second insulation film wall portions are sequentially connected at the head and tail to form the mounting space, one of the plurality of second insulation film wall portions is formed with a first through hole, and the first through hole is used for corresponding to the explosion-proof valve opening of the shell.

[0009] According to some embodiments of the present application, the first through hole is a plurality of.

[0010] According to some embodiments of the present application, at least one of the plurality of second insulation film wall portions is formed with a second through hole, and the second through hole is used for electrolyte infiltration.

[0011] According to some embodiments of the present application, the second insulation film wall portion formed with the first through hole is formed with the second through hole.

[0012] According to some embodiments of the present application, one of the plurality of second insulation film wall portions is opposite and spaced apart from the first insulation film wall portion, and the second insulation film wall portion opposite and spaced apart from the first insulation film wall portion is formed with the first through hole and the second through hole.

[0013] According to some embodiments of the present application, the second through hole is a plurality of, and the plurality of second through holes are arranged along the length direction of the insulation film.

[0014] According to some embodiments of the present application, two of the plurality of second insulation film wall portions are adjacent to the first insulation film wall portion, and the outer surface of at least one of the two second insulation film wall portions adjacent to the first insulation film wall portion is provided with a protective layer.

[0015] The battery cell according to the embodiments of the present application comprises: a shell, a side wall of the shell is formed with a welding area, an electrode assembly and an insulation film, the insulation film is the insulation film of the above-mentioned embodiments, the electrode assembly is installed in the mounting space, and the electrode assembly and the insulation film are both installed in the shell, and the first insulation film wall portion corresponds to the welding area.

[0016] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0018] Figure 1is a schematic diagram of an insulating film structure of an embodiment of the present application;

[0019] Figure 2 is a sectional view of a first insulating film wall part of an embodiment of the present application;

[0020] Figure 3 is a sectional view of an assembly of an insulating film and a shell of an embodiment of the present application.

[0021] Reference signs:

[0022] insulating film 100;

[0023] insulating film main body 10; first insulating film wall part 11; second insulating film wall part 12; first through hole 13; second through hole 14; mounting space 15;

[0024] protective layer 20; shell 21. DETAILED DESCRIPTION

[0025] Embodiments of the present application will be described in detail below, examples of which are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are only used to explain the present application and cannot be understood as a limitation of the present application.

[0026] Reference will be made below to Figures 1-3 describing an insulating film 100 for a battery monomer and a battery monomer according to an embodiment of the present application.

[0027] As shown in Figures 1-3 , the insulating film 100 for a battery monomer according to an embodiment of the present application comprises: an insulating film main body 10, the insulating film main body 10 is annular to define a mounting space 15 for mounting an electrode assembly of a battery monomer, the insulating film main body 10 has a first insulating film wall part 11, the first insulating film wall part 11 is used to correspond to a welding area of a shell 21 of the battery monomer, a protective layer 20, the protective layer 20 is arranged on an outer surface of the first insulating film wall part 11.

[0028] Among them, the insulating film 100 can be made of a polymer material, for example: the insulating film 100 can be made of polypropylene (PP), polyethylene (PE), polyimide (PI) and other insulating materials, the polymer material has excellent insulating performance, high temperature resistance and chemical corrosion resistance, which can adapt to the complex environment of the battery monomer during work, and further ensure the safety and reliability of the battery monomer.

[0029] The insulating film body 10 is annular to define a mounting space 15 for mounting an electrode assembly of a battery monomer, so that the insulating film body 10 can wrap the electrode assembly in all directions, provide reliable insulation isolation effect, ensure the insulation between the electrode assembly and the shell 21 of the battery monomer, prevent the electrode assembly from short circuit, and further ensure the safety and stability of the battery monomer. Further, the opposite ends of the mounting space 15 can be open.

[0030] The insulating film body 10 has a first insulating film wall part 11 corresponding to a welding area of the shell 21 of the battery monomer. Specifically, the shell 21 of the battery monomer can be formed by bending welding, and the welding area of the shell 21 is extremely prone to burrs or welding protrusions on the surface inside the shell 21, which can easily scratch the insulating film body 10 and cause short circuit of the electrode assembly. Therefore, the first insulating film wall part 11 needs to be spaced apart from the welding area to protect the insulating film 100 from being scratched by the burrs or welding protrusions of the welding area of the shell 21 of the battery monomer. By providing the protective layer 20 on the outer surface of the first insulating film wall part 11, the first insulating film wall part 11 can be spaced apart from the welding area of the shell 21, and the protective layer 20 is located between the first insulating film wall part 11 and the welding area of the shell 21, which can reduce the risk of the insulating film 100 being scratched by the burrs or welding protrusions of the welding area of the shell 21 of the battery monomer, reduce the risk of short circuit of the electrode assembly, and further improve the safety and reliability of the battery monomer.

[0031] The protective layer 20 can be a composite wear-resistant coating, which can be silicon carbide, ceramic particles, high molecular wear-resistant material, etc. By brushing or spraying the wear-resistant coating on the outer surface of the first insulating film wall part 11, not only can the welding area be effectively isolated from the first insulating film wall part 11 to reduce the risk of the first insulating film wall part 11 being scratched by the burrs or protrusions of the welding area, but also the wear-resistant performance of the first insulating film wall part 11 can be enhanced, thereby improving the safety, reliability and service life of the battery monomer. Moreover, the protective layer 20 occupies a small space, and the brushing and spraying operation of the protective layer 20 is simple, thereby reducing the assembly difficulty and manufacturing cost of the battery monomer.

[0032] According to the insulating film 100 for the battery monomer, the insulating film main body 10 is arranged in a ring shape to define the mounting space 15 for mounting the electrode assembly of the battery monomer, the insulating film main body 10 can realize insulation between the electrode assembly and the shell 21 of the battery monomer, so as to reduce the risk of short circuit of the battery monomer, the insulating film main body 10 has the first insulating film wall part 11, the first insulating film wall part 11 is used for corresponding to the welding area of the shell 21 of the battery monomer, and the protective layer 20 is arranged on the outer surface of the first insulating film wall part 11, the insulating film 100 can be protected by the protective layer 20, the risk of the insulating film 100 being scratched by the welding seam of the welding area of the shell 21 of the battery monomer is reduced, so as to reduce the risk of short circuit of the battery monomer, and the safety and reliability of the battery monomer can be further improved, and the protective layer 20 has small occupied space and simple setting method, so as to reduce the assembly difficulty and manufacturing cost of the battery monomer.

[0033] According to some embodiments of the utility model, as shown in Figure 2 The thickness of the protective layer 20 is greater than or equal to 0.2mm, for example, the thickness of the protective layer 20 can be 0.2mm, 0.25mm, 0.3mm, 0.4mm and other values, but the utility model is not limited to this, the thickness of the protective layer 20 can also be other values, as long as the thickness of the protective layer 20 is greater than or equal to 0.2mm. The thickness of the protective layer 20 is greater than or equal to 0.2mm, which can significantly improve the wear resistance of the protective layer 20, so that the protective layer 20 can effectively resist the scratching of burrs or protrusions of the welding area, thereby improving the protection effect of the protective layer 20, which helps to reduce the damage of the first insulating film wall part 11 caused by burrs or protrusions, so as to maintain the insulation performance of the insulating film 100. And the thicker protective layer 20 can also play a certain buffering role, when the battery monomer is impacted or vibrated, the protective layer 20 can absorb part of the energy, reduce the impact and damage to the electrode assembly inside the battery monomer, protect the overall structure of the battery monomer from being damaged, thereby further improving the safety and reliability of the battery monomer. It should be noted that the upper limit value of the thickness of the protective layer 20 can be reasonably selected according to actual conditions.

[0034] According to some embodiments of the utility model, as shown in Figure 1 The insulating film main body 10 also has a plurality of second insulating film wall parts 12, the first insulating film wall part 11 and the plurality of second insulating film wall parts 12 are sequentially connected in a head-to-tail manner to form the mounting space 15, one of the plurality of second insulating film wall parts 12 forms the first through hole 13, and the first through hole 13 is used for corresponding to the explosion-proof valve opening of the shell 21.

[0035] The insulating film body 10 can further have a plurality of second insulating film wall portions 12, for example, the insulating film body 10 can have three, four, five or the like number of second insulating film wall portions 12, but the utility model is not limited to this, the insulating film body 10 can also have other numbers of second insulating film wall portions 12, as long as the insulating film body 10 has a plurality of second insulating film wall portions 12. The application is described by taking the insulating film body 10 having three second insulating film wall portions 12 as an example. But the number of second insulating film wall portions 12 can also be reasonably set according to the actual situation. The first insulating film wall portion 11 and the plurality of second insulating film wall portions 12 are sequentially connected at the head and tail to form the mounting space 15, and the size and shape of the mounting space 15 can be flexibly controlled by adjusting the number of second insulating film wall portions 12, so that the insulating film body 10 can adapt to the mounting requirements of electrode assemblies of different sizes and shapes.

[0036] One of the plurality of second insulating film wall portions 12 can be formed with a first through hole 13, the first through hole 13 is used for corresponding to the explosion-proof valve opening of the shell 21, can provide a ventilation space for the explosion of the explosion-proof valve, ensure that the explosion-proof valve can work normally, so that the explosion-proof valve can release the pressure inside the battery monomer in time, prevent the battery monomer from exploding, and further ensure the safety and reliability of the battery monomer.

[0037] According to some embodiments of the utility model, as shown in Figure 1 The first through hole 13 can be multiple, for example, there can be two, three, four or the like number of first through holes 13, but the utility model is not limited to this, there can also be other numbers of first through holes 13, as long as the first through hole 13 is multiple. The plurality of first through holes 13 are used for corresponding to the explosion-proof valve opening of the shell 21, can provide a larger gas release channel, when the internal pressure of the battery monomer increases to a certain value, thereby reducing the internal pressure of the battery monomer more quickly, prevent explosion or damage caused by too high pressure, so that the response of the explosion-proof valve is more rapid and effective. And the design of the plurality of first through holes 13 provides additional safety redundancy, even if one of the first through holes 13 is blocked, the other first through holes 13 can still work normally, ensure that the internal pressure of the battery monomer is effectively released, and further can significantly improve the safety and reliability of the battery monomer.

[0038] According to some embodiments of the utility model, as shown in Figure 1 At least one of the plurality of second insulating film wall portions 12 is formed with a second through hole 14, and the second through hole 14 is used for electrolyte infiltration.

[0039] At least one of the plurality of second insulating film wall portions 12 is formed with a second through hole 14, for example, one, two, three or other number of second insulating film wall portions 12 among the plurality of second insulating film wall portions 12 can be formed with the second through hole 14, but the utility model is not limited to this, and other number of second insulating film wall portions 12 among the plurality of second insulating film wall portions 12 can also be formed with the second through hole 14, as long as at least one of the plurality of second insulating film wall portions 12 is formed with the second through hole 14. The second through hole 14 is used for electrolyte infiltration, and the electrolyte penetrates into the inside of the electrode assembly through the second through hole 14, so that the electrolyte can infiltrate into the electrode assembly and other components inside the battery monomer. After the electrolyte infiltrates into the surface of the electrode assembly, a uniform interface that is beneficial to electrochemical reaction can be formed between the electrode assembly and the electrolyte, which helps the ions in the electrolyte to quickly contact the reactants on the surface of the electrode assembly and carry out electrochemical reaction, thereby greatly improving the reaction rate of the electrode assembly, and further improving the performance and service life of the battery monomer.

[0040] According to some embodiments of the utility model, as shown in Figure 1 The second insulating film wall portion 12 formed with the first through hole 13 can be formed with the second through hole 14, so as to integrate the first through hole 13 and the second through hole 14 on the same second insulating film wall portion 12, which can simplify the structural design of the battery monomer, thereby reducing the manufacturing cost of the battery monomer, and the integration of the first through hole 13 and the second through hole 14 on the same second insulating film wall portion 12 is also convenient for maintenance and repair.

[0041] According to some embodiments of the utility model, as shown in Figure 1 One of the plurality of second insulating film wall portions 12 is opposite and spaced apart from the first insulating film wall portion 11, and the second insulating film wall portion 12 opposite and spaced apart from the first insulating film wall portion 11 is formed with the first through hole 13 and the second through hole 14.

[0042] One of the plurality of second insulating film wall portions 12 is opposite and spaced apart from the first insulating film wall portion 11, which can provide support for the electrode assembly and help maintain the stability of the battery monomer. Reasonable spacing design can also reduce deformation caused by material thermal expansion or internal reaction of the battery monomer, thereby prolonging the service life of the battery monomer. The second insulating film wall portion 12 opposite and spaced apart from the first insulating film wall portion 11 is formed with the first through hole 13 and the second through hole 14, which can integrate the first through hole 13 and the second through hole 14 on the same second insulating film wall portion 12, further reducing the manufacturing cost and complexity of the battery monomer.

[0043] According to some embodiments of the utility model, as shown in Figure 1 The second through hole 14 is a plurality of second through holes 14 arranged along the length direction of the insulating film 100.

[0044] The second through holes 14 are multiple, for example, there can be two, three, four or the like, but the utility model is not limited thereto, and there can be other numbers of second through holes 14, as long as the second through holes 14 are multiple. The multiple second through holes 14 are arranged along the length direction of the insulating film 100, which can ensure that the electrolyte flows along a definite direction during the infiltration process, reduces the disorder and randomness in the infiltration process, thereby improving the uniformity of the infiltration, helps the electrolyte to be uniformly distributed to the inside of the battery monomer, and the uniform electrolyte infiltration helps to form a more stable ion transmission channel, improves the transmission rate of ions in the electrolyte, thereby accelerating the electrochemical reaction process inside the battery monomer and improving the discharge efficiency and power density of the battery monomer. The uniform electrolyte infiltration also helps to form a stable and uniform solid electrolyte interface film (SEI film), which can protect the electrode assembly from the corrosion of the electrolyte and improve the cycle stability and safety of the battery monomer.

[0045] According to some embodiments of the utility model, as shown in Figure 1 The outer surface of at least one of the two second insulating film wall portions 12 adjacent to the first insulating film wall portion 11 is provided with a protective layer 20.

[0046] The two second insulating film wall portions 12 adjacent to the first insulating film wall portion 11 are connected with other second insulating film wall portions 12 to form a mounting space 15 for mounting the electrode assembly of the battery monomer.

[0047] The outer surface of at least one of the two second insulating film wall portions 12 adjacent to the first insulating film wall portion 11 is provided with a protective layer 20, for example, the outer surface of one of the two second insulating film wall portions 12 adjacent to the first insulating film wall portion 11 is provided with a protective layer 20, or the outer surfaces of the two second insulating film wall portions 12 adjacent to the first insulating film wall portion 11 are both provided with protective layers 20, as long as the outer surface of at least one of the two second insulating film wall portions 12 adjacent to the first insulating film wall portion 11 is provided with a protective layer 20.

[0048] Specifically, when the welding area of the shell 21 of the battery cell is located at the corner between two adjacent wall surfaces of the shell 21, the burr or welding protrusion of the welding area has the risk of scratching the first insulating film wall part 11 and the second insulating film wall part 12 adjacent to the welding area, the outer surface of the corresponding second insulating film wall part 12 among the two second insulating film wall parts 12 adjacent to the first insulating film wall part 11 is provided with the protective layer 20, which can increase the protective area of the insulating film 100, reduce the risk of the corresponding second insulating film wall part 12 being scratched and damaged by the burr or welding protrusion, further reduce the risk of the insulating film 100 being scratched by the burr or welding protrusion of the welding area of the shell 21 of the battery cell, so as to prevent the electrode assembly from short circuiting, and further improve the safety and reliability of the battery cell.

[0049] The battery cell according to the embodiment of the present application comprises: a shell 21, a side wall of the shell 21 is formed with a welding area, an electrode assembly and an insulating film 100, the insulating film 100 is the insulating film 100 of the above embodiment, the electrode assembly is installed in the installation space 15, the electrode assembly and the insulating film 100 are both installed in the shell 21, and the first insulating film wall part 11 corresponds to the welding area, the protective layer 20 is arranged on the outer surface of the first insulating film wall part 11, which can separate the first insulating film wall part 11 from the welding area of the shell 21, reduce the risk of the insulating film 100 being scratched by the burr or welding protrusion of the welding area of the shell 21 of the battery cell, reduce the risk of the battery cell short circuiting, and further improve the safety and reliability of the battery cell. Moreover, the protective layer 20 occupies a small space, and the brushing and spraying operations of the protective layer 20 are simple, which can further reduce the assembly difficulty and manufacturing cost of the battery cell.

[0050] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0051] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. An insulating film for a battery cell, characterized by, The insulating film body is annular to define an installation space for installing an electrode assembly of the battery cell, and has a first insulating film wall part corresponding to a welding area of a shell of the battery cell. The protective layer is arranged on an outer surface of the first insulating film wall part. The thickness of the protective layer is greater than or equal to 0.2 mm.

2. The insulating film according to claim 1, characterized by The insulating film body further has a plurality of second insulating film wall parts, the first insulating film wall part and the plurality of second insulating film wall parts are sequentially connected in a head-to-tail manner to form the installation space, one of the plurality of second insulating film wall parts is formed with a first through hole corresponding to an explosion-proof valve opening of the shell.

3. The insulating film according to claim 1, characterized by The first through hole is a plurality of first through holes.

4. The insulating film according to claim 3, characterized by At least one of the plurality of second insulating film wall parts is formed with a second through hole for electrolyte infiltration.

5. The insulating film according to claim 3, characterized by The second insulating film wall part formed with the first through hole is formed with the second through hole.

6. The insulating film according to claim 5, characterized by One of the plurality of second insulating film wall parts is opposite and spaced apart from the first insulating film wall part, and the second insulating film wall part opposite and spaced apart from the first insulating film wall part is formed with the first through hole and the second through hole.

7. The insulating film according to claim 5, wherein The second through hole is a plurality of second through holes, and the plurality of second through holes are arranged along a length direction of the insulating film.

8. The insulating film according to claim 7, characterized by Two of the plurality of second insulating film wall parts are adjacent to the first insulating film wall part, and an outer surface of at least one of the two second insulating film wall parts adjacent to the first insulating film wall part is provided with the protective layer.

9. The insulating film according to any one of claims 3 to 8, wherein The shell has a side wall formed with a welding area; 10. A battery cell characterized by, The electrode assembly and the insulating film according to any one of claims 1-9 are installed in the shell, and the first insulating film wall part corresponds to the welding area. ​ ​

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