Battery cell structure, battery module, battery pack and vehicle

Abstract

The utility model discloses a battery cell structure, a battery module, a battery pack and a vehicle, and relates to the technical field of new energy batteries. The battery cell structure comprises a battery cell body, an insulating film and a top cover assembly, the outer surface of the battery cell body is coated with the insulating film, the top cover assembly is provided with a positioning part, the insulating film is provided with a through hole corresponding to the positioning part, the top cover assembly is fixedly installed at the top of the battery cell body, and the top cover assembly is provided with a through hole corresponding to the positioning part. And the positioning part is positioned and accommodated in the through hole. According to the battery cell structure, the battery module, the battery pack and the vehicle, the problems of various procedures, complex process, low yield and poor safety of surface film coating of the existing battery cell through a hot melting process can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy batteries, and in particular to a battery core structure, a battery module, a battery pack and a vehicle. Background Art

[0002] During the production of lithium-ion batteries, the Mylar film needs to be wrapped around the battery core. Mylar film is an insulating film. The Mylar film is in the form of a whole sheet, which needs to be bent and pressed to fit the contour of the core to make it fit the contour of the core. The formed Mylar film is then heat-fused to the lower plastic of the battery cell and finally fixed with glue.

[0003] The existing technology has the following disadvantages: First, after the bare battery cell insulating sheet is hot-melted, there are residues such as residues, wiredrawing or bulges on the welded surface, which can easily cause laser welding explosion points, welding failure and other defects in the battery cell manufacturing process, resulting in product scrapping; Second, the Mylar hot-melt process requires the addition of a hot-melt welding step, which is complicated and lengthens the entire battery cell manufacturing process, and requires the coordination of equipment and site, and the equipment occupies a large area; Third, if the hot-melt temperature is too high or the time is too long, wiredrawing is easily formed, and the wiredrawing clamped into the position of the top cover laser welding is also prone to cause welding explosion points. Utility Model Content

[0004] The purpose of the utility model is to provide a battery cell structure, a battery module, a battery pack and a vehicle, which can solve the problems of numerous procedures, complex process, low yield rate and poor safety in existing battery cells that have their surface coated by hot-melt process.

[0005] The embodiment of the utility model is achieved as follows:

[0006] In a first aspect of the embodiment of the utility model, a battery cell structure is provided, comprising a battery cell body, an insulating film and a top cover assembly, wherein the insulating film is coated on the outer surface of the battery cell body, a positioning portion is provided on the top cover assembly, a through hole is provided on the insulating film corresponding to the positioning portion, the top cover assembly is fixedly mounted on the top of the battery cell body, and the positioning portion is positioned and accommodated in the through hole. The battery cell structure can solve the problems of numerous processes, complex processes, low yield rate and poor safety in the existing battery cell surface coating by hot melt process.

[0007] As an implementable method, the battery cell body includes a side surface and a top surface and a bottom surface located at opposite ends of the side surface, the insulating film includes a first film layer and a second film layer connected to the first film layer, the first film layer is bonded to the side surface, and the second film layer can be folded relative to the first film layer toward the side close to the top surface.

[0008] As an implementable manner, the projection shapes of the side surface and the first film layer are both rectangular, the number of the second film layers is four, and the four second film layers are respectively connected to four sides of the opening of the first film layer close to the top surface.

[0009] As an implementable manner, the through hole is located on the second film layer, and a buckle seam communicating with the through hole is provided on a side of the second film layer away from the first film layer, and the positioning portion is accommodated in the through hole through the buckle seam.

[0010] As an practicable manner, along the direction in which the second film layer is away from the first film layer, the width of the buckle seam first gradually decreases and then gradually increases.

[0011] As an practicable manner, the top cover assembly includes a lower plastic and a cover plate connected to each other, the positioning portion is a positioning column arranged on the lower plastic, and the folded second film layer is clamped between the lower plastic and the cover plate.

[0012] As an practicable manner, the projection shape of the second film layer is a trapezoid, and the sides of two adjacent second film layers that are close to each other are in contact.

[0013] The second aspect of the present invention provides a battery module, including the above-mentioned battery cell structure. The battery cell structure can solve the problems of numerous procedures, complex process, low yield and poor safety in the existing battery cell surface coating by hot melting process.

[0014] The third aspect of the present invention provides a battery pack, including the above-mentioned battery module. The battery cell structure can solve the problems of numerous procedures, complex process, low yield and poor safety in the existing battery cells that are coated on the surface by hot melting process.

[0015] In a fourth aspect of the embodiment of the utility model, a vehicle is provided, comprising the above-mentioned battery pack. The battery cell structure can solve the problems of numerous procedures, complex process, low yield and poor safety in the existing battery cells that are coated on the surface by hot melting process.

[0016] The beneficial effects of the embodiments of the utility model include:

[0017] The cell structure provided by the present application includes a cell body, an insulating film and a top cover assembly. In the actual production process, the insulating film is first coated on the outer surface of the cell body. Since a positioning portion is provided on the top cover assembly and a through hole is provided on the insulating film corresponding to the positioning portion, it is only necessary to fix the top cover assembly on the top of the cell body, and the positioning portion is positioned and accommodated in the through hole, so that the top cover assembly can provide a pressing force to press and fix the insulating film and the cell body. Compared with the prior art, the cell structure omits the hot melt process, so it can solve the problems of the existing cell surface coating by hot melt process, which has many processes, complex processes, low yield rate and poor safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of the structure of an insulating film provided by an embodiment of the utility model;

[0020] Figure 2 One of the structural schematic diagrams of the battery cell structure provided by the embodiment of the utility model;

[0021] Figure 3 The second structural schematic diagram of the battery cell structure provided by the embodiment of the utility model;

[0022] Figure 4 The third structural schematic diagram of the battery cell structure provided by the embodiment of the utility model;

[0023] Figure 5 A schematic diagram of the structure of the lower plastic provided by an embodiment of the utility model;

[0024] Figure 6 A schematic diagram of the structure of the cover plate provided in the embodiment of the utility model;

[0025] Figure 7 This is a fourth structural schematic diagram of the battery cell structure provided in an embodiment of the utility model.

[0026] Icons: 100 - battery cell structure; 10 - battery cell body; 20 - insulating film; 21 - first film layer; 22 - second film layer; 221 - through hole; 222 - buckle seam; 30 - top cover assembly; 31 - lower plastic; 311 - positioning column; 32 - cover plate; 321 - positioning hole. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0030] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the utility model product is usually placed when in use, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0031] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0032] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 it can be indirectly connected through an intermediate medium, or it can be a connection between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] Please refer to Figures 1 to 7 The embodiment of the present application provides a battery pack, including a battery box and a plurality of battery modules arranged in parallel in the battery box, so as to provide electric energy to an electric device (such as a vehicle) through the battery pack, thereby meeting the use requirements of the electric device. Each battery module includes a plurality of battery cell structures 100 arranged in sequence, and the plurality of battery cell structures 100 can achieve a larger output current or output voltage by electrical connection in series, parallel or series-parallel connection.

[0034] In the manufacturing process of the battery pack, the cell structure 100 is used as the smallest component unit of the battery pack. First, multiple cell structures 100 are electrically connected using the above-mentioned electrical connection method, and then packaged to form a battery module. Then, multiple battery modules are combined and controlled by a battery management system (BMS) to finally form a battery pack.

[0035] In order to avoid short circuits and other phenomena during the use of the battery pack, it is necessary to improve the safety and reliability of the battery cell structure 100. In the prior art, Mylar film is usually coated on the surface of the battery core to provide insulation and protection. Since the raw material of the Mylar film is a sheet structure, before coating, the Mylar film needs to be bent according to the contour of the battery core. When coating, the Mylar film is first pressed and fitted to the surface of the battery core, and then the formed Mylar film is hot-melted to the lower plastic 31 of the battery cell, and finally fixed with glue.

[0036] In the prior art, the design scheme of coating the surface of the battery roll with Mylar film through a hot melt process requires an additional hot melt process, which will lengthen the entire battery cell manufacturing process and increase the manufacturing cost. Moreover, the hot melt process itself has the disadvantage of being complicated. Not only is it easy to produce residues such as wiredrawing during hot melting, but it is also easy to produce various residues, wiredrawing or bulges on the surface of the battery cell after hot melting. Moreover, in the subsequent laser welding process, these residues are very likely to produce welding explosion points, resulting in a low product yield and poor safety.

[0037] In order to solve the above problems, Figures 1 to 7As shown, the present application provides a battery cell structure 100, which includes a battery cell body 10, an insulating film 20 and a top cover assembly 30. The insulating film 20 is coated on the outer surface of the battery cell body 10, and a positioning portion is provided on the top cover assembly 30. A through hole 221 is provided on the insulating film 20 corresponding to the positioning portion. The top cover assembly 30 is fixedly installed on the top of the battery cell body 10, and the positioning portion is positioned and accommodated in the through hole 221. The battery cell structure 100 can solve the problems of the existing battery cell having a surface coating by a hot melt process, which has many processes, complex processes, low yield rate and poor safety.

[0038] It should be noted that if Figure 2 As shown, the battery cell structure 100 includes a battery cell body 10, an insulating film 20 and a top cover assembly 30, wherein the above-mentioned battery cell body 10 can be understood as a battery roll core in the prior art, the insulating film 20 can be selected from the Mylar film in the prior art, and the top cover assembly 30 at least includes a lower plastic 31 and a cover plate 32, which are fixedly installed on the top of the battery cell body 10 through the top cover assembly 30, thereby forming the battery cell structure 100.

[0039] Similar to the prior art, the insulating film 20 is coated on the outer surface of the battery cell body 10 to insulate and protect the battery cell body 10; different from the prior art, the insulating film 20 no longer needs to be fixed to the lower plastic 31 through a hot melt process, but a positioning portion is provided on the top cover assembly 30, and a through hole 221 is provided on the insulating film 20 corresponding to the positioning portion, the top cover assembly 30 is fixedly installed on the top of the battery cell body 10, and the positioning portion is positioned and accommodated in the through hole 221, thereby forming a battery cell structure 100.

[0040] In the actual production process, since a positioning portion is provided on the top cover assembly 30 and a through hole 221 is provided on the insulating film 20 corresponding to the positioning portion, after the insulating film 20 is pressed and fitted to the outer surface of the battery cell body 10, it is only necessary to align the positioning portion with the through hole 221, and then fix the top cover assembly 30 on the top of the battery cell body 10. At this time, the positioning portion is positioned and accommodated in the through hole 221, and the clamping force can be provided by the top cover assembly 30, thereby pressing and fixing the insulating film 20.

[0041] For example, in some embodiments, the insulating film 20 is clamped between the battery cell body 10 and the top cover assembly 30, or, in other embodiments, the insulating film 20 is clamped between two adjacent parts of the top cover assembly 30. It is only necessary to satisfy the above-mentioned requirements that the insulating film 20 is coated on the outer surface of the battery cell body 10, the top cover assembly 30 is fixedly installed on the top of the battery cell body 10, and the positioning portion is positioned and accommodated in the through hole 221.

[0042] In summary, the battery cell structure 100 provided in the present application includes a battery cell body 10, an insulating film 20 and a top cover assembly 30. In the actual production process, the insulating film 20 is first coated on the outer surface of the battery cell body 10. Since a positioning portion is provided on the top cover assembly 30, and a through hole 221 is provided on the insulating film 20 corresponding to the positioning portion, it is only necessary to fix the top cover assembly 30 on the top of the battery cell body 10, and the positioning portion is positioned and accommodated in the through hole 221, so that the top cover assembly 30 can provide a clamping force, thereby achieving compression and fixing of the insulating film 20 and the battery cell body 10. Compared with the prior art, the battery cell structure 100 omits the hot melt process, and therefore can solve the problems of the existing battery cells having many processes, complex processes, low yield rate and poor safety in coating the surface of the battery cells through the hot melt process.

[0043] As an implementable approach, Figure 2 As shown, the battery cell body 10 includes a side surface and a top surface and a bottom surface at opposite ends of the side surface, and the insulating film 20 includes a first film layer 21 and a second film layer 22 connected to the first film layer 21. The first film layer 21 is attached to the side surface, and the second film layer 22 can be folded toward a side close to the top surface relative to the first film layer 21. Figure 4 As shown, the insulating film 20 may also include a third film layer connected to the first film layer 21 and opposite to the second film layer 22, and the third film layer is bonded to the bottom surface. Those skilled in the art should be able to make reasonable selections and designs based on actual conditions, and no specific restrictions are made here.

[0044] In the actual production process, Figures 1 to 3 As shown, the second film layer 22 can be folded outward first so that the battery cell body 10 can enter the covering range formed by the first film layer 21, thereby avoiding interference with the movement process of the battery cell body 10, or causing the second film layer 22 to be pressed into the covering range formed by the first film layer 21 by the battery cell body 10 and unable to be exposed; then after the battery cell body 10 and the first film layer 21 are installed in place, the second film layer 22 is folded inward so that it can fit with the top of the battery cell body 10 through the second film layer 22.

[0045] For example, Figure 1 As shown, in the present embodiment, the battery cell body 10 is a square battery cell, and correspondingly, the above-mentioned side surface refers to the whole formed by the four side walls of the square battery cell. At this time, the projection shapes of the side surface and the first film layer 21 are both rectangular, and correspondingly, the number of the second film layers 22 is four, and the four second film layers 22 are respectively connected to the four sides of the opening of the first film layer 21 close to the top surface.

[0046] Of course, in other embodiments, the battery body 10 can also be a cylindrical battery, and correspondingly, the above-mentioned side refers to the entire circumferential wall of the cylindrical battery. At this time, the projection shapes of the side and the first film layer 21 are both circular. As for the second film layer 22, the number of the second film layers 22 can be at least two, and at least two second film layers 22 are respectively connected to the edges of the openings of the first film layer 21 close to the top surface. Regarding the specific selection of the battery body 10 and the corresponding structural design of the first film layer 21 and the second film layer 22, those skilled in the art should be able to make reasonable selections and designs according to actual conditions, and no specific restrictions are made here.

[0047] Considering that the top cover assembly 30 is fixedly installed on the top of the battery cell body 10, the through hole 221 is set on the second film layer 22. It is originally necessary to fix multiple components of the top cover assembly 30 on the battery cell body 10 in the order of being close to the battery cell body 10 and being far away from the battery cell body 10 to ensure that the positioning part is positioned and accommodated in the through hole 221. There is a problem that the assembly operation of the top cover assembly 30 is complicated. In order to solve this problem, Figure 1 As shown, a buckle seam 222 connected to the through hole 221 is provided on the side of the second film layer 22 away from the first film layer 21, so that the positioning part can be accommodated in the through hole 221 through the buckle seam 222, so that the top cover assembly 30 can be directly assembled together, and then the entire top cover assembly 30 is assembled on the battery cell body 10 without affecting the subsequent positioning of the positioning part in the through hole 221.

[0048] For example, Figures 4 to 7 As shown, in this embodiment, the top cover assembly 30 at least includes a lower plastic 31 and a cover plate 32 connected to each other, a positioning column 311 (i.e., the positioning portion mentioned above) is provided on the lower plastic 31, and a positioning hole 321 is provided on the cover plate 32, and the free end of the positioning column 311 is positioned and accommodated in the positioning hole 321, so that the lower plastic 31 and the cover plate 32 are fixedly connected to form the top cover assembly 30. In actual use, the lower plastic 31 is fixedly connected to the battery body 10, and the folded second film layer 22 is clamped between the lower plastic 31 and the cover plate 32, so that the top cover assembly 30 can provide a pressing force to the insulating film 20 close to the battery body 10.

[0049] In this way, if Figure 7As shown, the entire top cover assembly 30 can be first installed and fixed on the top of the battery cell body 10 through the lower plastic 31, and then the second film layer 22 can be folded inwards and inserted into the gap between the lower plastic 31 and the cover plate 32, and then the opposite sides of the buckle seam 222 pass through the opposite sides of the positioning part and converge again, so as to finally form an assembly state in which the positioning part is accommodated in the through hole 221. The advantage of this is that in addition to being able to compress the second film layer 22 through the cooperation between the top cover assembly 30 and the battery cell body 10, the second film layer 22 can also be limited through the cooperation between the lower plastic 31 and the cover plate 32, which can not only simplify the assembly difficulty of the top cover assembly 30, but also further clamp and fix the second film layer 22.

[0050] As an implementable approach, Figure 7 As shown, along the direction in which the second film layer 22 is away from the first film layer 21, the width of the buckle seam 22 first gradually decreases and then gradually increases. In this way, on the one hand, it is convenient for the positioning part to pass through the buckle seam 222, or the opposite sides of the buckle seam 222 are convenient to pass through the opposite sides of the positioning part and converge again; on the other hand, after the installation is completed, the opposite sides of the buckle seam 222 can be as close to each other as possible to maintain the assembly state in which the positioning part is accommodated in the through hole 221.

[0051] As an implementable approach, Figure 7 As shown, the projection shape of the second film layer 22 is a trapezoid, and the sides of two adjacent second film layers 22 that are close to each other are in contact. In addition, the sides of two adjacent second film layers 22 that are close to each other can also overlap or have a large gap. Compared with the state with a large gap, the contact state can ensure that the second film layer 22 can play an insulating and protective role; compared with the overlapping state, the contact state can avoid the impact on the assembly of the top cover assembly 30 and the battery body 10 caused by the overlap of the second film layer 22 at the junction.

[0052] As an practicable manner, the first film layer 21 and the second film layer 22 are an integrated structure to improve the integrity and sealing of the insulating film 20. In the actual production process, the Mylar film can be cut and bent according to the contour shape of the battery body 10.

[0053] The embodiment of the present application further provides a vehicle, comprising the above-mentioned battery pack. Since the structure and beneficial effects of the battery pack have been described in detail in the above-mentioned embodiment, they will not be repeated here.

[0054] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

[0055] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present utility model will not further describe various possible combinations.

Claims

1. A battery cell structure, characterized in that: It includes a battery cell body, an insulating film and a top cover assembly, wherein the insulating film is coated on the outer surface of the battery cell body, the top cover assembly is provided with a positioning portion, the insulating film is provided with a through hole corresponding to the positioning portion, the top cover assembly is fixedly installed on the top of the battery cell body, and the positioning portion is positioned and accommodated in the through hole.

2. The battery cell structure according to claim 1, characterized in that: The battery cell body includes a side surface and a top surface and a bottom surface located at opposite ends of the side surface. The insulating film includes a first film layer and a second film layer connected to the first film layer. The first film layer is attached to the side surface, and the second film layer can be folded relative to the first film layer toward the side close to the top surface.

3. The battery cell structure according to claim 2, characterized in that: The projection shapes of the side surface and the first film layer are both rectangular. The number of the second film layers is four, and the four second film layers are respectively connected to four sides of the opening of the first film layer close to the top surface.

4. The battery cell structure according to claim 3, characterized in that: The through hole is located on the second film layer, and a buckle seam communicating with the through hole is provided on the side of the second film layer away from the first film layer, and the positioning portion is accommodated in the through hole through the buckle seam.

5. The battery cell structure according to claim 4, characterized in that: Along the direction in which the second film layer moves away from the first film layer, the width of the buckle seam first gradually decreases and then gradually increases.

6. The battery cell structure according to claim 2, characterized in that: The top cover assembly includes a lower plastic and a cover plate that are connected to each other, the positioning portion is a positioning column arranged on the lower plastic, and the folded second film layer is clamped between the lower plastic and the cover plate.

7. The battery cell structure according to claim 2, characterized in that: The projection shape of the second film layer is a trapezoid, and the sides of two adjacent second film layers that are close to each other are in contact.

8. A battery module, characterized in that: The invention comprises the battery core structure as described in any one of claims 1 to 7.

9. A battery pack, characterized in that: Comprising the battery module as claimed in claim 8.

10. A vehicle, characterized in that: A battery pack comprising the battery pack of claim 9.

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