Battery cell and secondary battery

Abstract

The utility model provides a battery cell and a secondary battery. The battery cell comprises a cover plate assembly, a first electrode and a second electrode, the shell is matched with the cover plate assembly to form an accommodating space; the electrode assembly is arranged in the accommodating space; the insulation film is located in the containing space and wraps the electrode assembly, the insulation film comprises bottom insulation layers and side insulation layers, the bottom insulation layers are arranged at the bottom of the electrode assembly in a stacked mode, each side face of the electrode assembly is provided with at least one side insulation layer, and the side insulation layers are arranged on the side faces of the electrode assembly. And each bottom insulating layer and the corresponding side insulating layer are integrally formed and connected. The battery cell and the secondary battery provided by the utility model are simple in structure, convenient to manufacture and high in stability, and short circuit or mechanical damage of the battery cell can be avoided.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell and a secondary battery. Background Technology

[0002] With the continuous development of the new energy industry, higher requirements are being placed on battery cells. Battery cells are mainly classified into prismatic, cylindrical, and pouch cells based on their outer casing structure. For prismatic cells, the internal electrode assembly is usually wrapped with an insulating film to isolate it from the casing. This insulating film is relatively thin. To further prevent the bottom of the electrode assembly from contacting the casing, a bottom support plate is placed between the bottom insulating film and the casing. The bottom support plate is usually fixed to the insulating film using a heat-fusion method. However, this connection method is not very secure. Under harsh operating conditions, the bottom support plate is easily detached due to external forces, exposing the bottom of the electrode assembly and making it prone to short circuits or mechanical damage. Therefore, there is an urgent need for a battery cell with better stability. Utility Model Content

[0003] In view of this, the purpose of this application is to provide a battery cell and a secondary battery to solve the related problems mentioned in the background art.

[0004] In a first aspect, this application provides a battery cell, comprising: a cover plate assembly; a housing that cooperates with the cover plate assembly to form a receiving space; an electrode assembly disposed within the receiving space; and an insulating film located within the receiving space and covering the electrode assembly, the insulating film comprising a bottom insulating layer and side insulating layers, the bottom of the electrode assembly having multiple layers of the bottom insulating layer stacked thereon, each side of the electrode assembly having at least one side insulating layer, and each bottom insulating layer being integrally formed and connected with the side insulating layer.

[0005] Furthermore, the side insulating layer includes a first side insulating layer and a second side insulating layer integrally formed and connected, the first side insulating layer abutting against the sidewall of the electrode assembly opposite to it along its thickness direction, and the second side insulating layer abutting against the sidewall of the electrode assembly opposite to it along its length direction; the bottom insulating layer includes a first bottom insulating layer and a second bottom insulating layer, the first bottom insulating layer being integrally formed and connected to the first side insulating layer, and the second bottom insulating layer being integrally formed and connected to the second side insulating layer.

[0006] Furthermore, the bottom insulating layer comprises two first bottom insulating layers and one second bottom insulating layer, with the two first bottom insulating layers located between the second bottom insulating layer and the electrode assembly.

[0007] Furthermore, the length of the first bottom insulating layer is equal to the length of the electrode assembly, and the width is greater than or equal to 1 / 2 of the thickness of the electrode assembly.

[0008] Furthermore, the width of the first bottom insulating layer is equal to the thickness of the electrode assembly.

[0009] Furthermore, the length of the second bottom insulating layer is equal to the length of the electrode assembly, and the width is equal to the thickness of the electrode assembly.

[0010] Furthermore, the side insulating layer also includes a third side insulating layer, which is integrally formed and connected with the second bottom insulating layer and abuts against the second side insulating layer.

[0011] Furthermore, the height of the third side insulating layer is less than or equal to the height of the electrode assembly.

[0012] Furthermore, each of the bottom insulating layers is provided with impregnation holes, and the impregnation holes on two adjacent bottom insulating layers do not overlap in their orthographic projection on the bottom of the housing.

[0013] A second aspect of this application provides a secondary battery, including the cell described in the first aspect above.

[0014] As can be seen from the above description, the battery cell and secondary battery provided in this application include a cover plate assembly; a shell that cooperates with the cover plate assembly to form a receiving space; an electrode assembly disposed within the receiving space; and an insulating film located within the receiving space, covering the electrode assembly. The insulating film includes a bottom insulating layer and side insulating layers. Multiple bottom insulating layers are stacked on the bottom of the electrode assembly, and each side of the electrode assembly has at least one side insulating layer. Each bottom insulating layer is integrally formed and connected to the side insulating layer. By stacking multiple bottom insulating layers on the bottom of the electrode assembly, the overall thickness of the bottom insulating structure is increased, thereby improving the protection effect on the bottom of the electrode assembly and preventing short circuits or mechanical damage to the battery cell. Furthermore, by integrally forming and connecting each bottom insulating layer with the side insulating layer, the stability is stronger than that of a heat-fused bottom plate, making it less prone to detachment under external forces, providing good protection for the electrode assembly, and reducing manufacturing difficulty and production costs. This battery cell and secondary battery have a simple structure, are easy to manufacture, and have strong stability, effectively preventing short circuits or mechanical damage to the battery cell. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1This is a schematic diagram of the cross-sectional structure of a battery cell according to an embodiment of this application;

[0017] Figure 2 This is a schematic diagram of the unfolded structure of an insulating film according to an embodiment of this application;

[0018] Figure 3 for Figure 2 A schematic diagram of the structure of the electrode assembly wrapped with an insulating film.

[0019] Reference numerals: 1. Cover plate assembly; 2. Housing; 3. Electrode assembly; 4. Insulating film; 4-1. Bottom insulating layer; 4-11. First bottom insulating layer; 4-12. Second bottom insulating layer; 4-2. Side insulating layer; 4-21. First side insulating layer; 4-22. Second side insulating layer; 4-23. Third side insulating layer; 4-3. Impregnation hole. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0021] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] With the continuous development of the new energy industry, higher requirements are being placed on battery cells. Battery cells are mainly classified into prismatic, cylindrical, and pouch cells based on their outer casing structure. For prismatic cells, the internal electrode assembly is usually wrapped with an insulating film to isolate it from the casing. This insulating film is relatively thin. To further prevent the bottom of the electrode assembly from contacting the casing, a bottom support plate is placed between the bottom insulating film and the casing. The bottom support plate is usually fixed to the insulating film using a heat-fusion method. However, this connection method is not very secure. Under harsh operating conditions, the bottom support plate is easily detached due to external forces, exposing the bottom of the electrode assembly and making it prone to short circuits or mechanical damage. Therefore, there is an urgent need for a battery cell with better stability.

[0023] The following describes specific embodiments in conjunction with the appendix. Figures 1 to 3 The technical solution of this application will be described in further detail.

[0024] In some embodiments of this application, a battery cell is provided, including: a cover plate assembly 1; a housing 2, which cooperates with the cover plate assembly 1 to form a receiving space; an electrode assembly 3, disposed within the receiving space; and an insulating film 4, located within the receiving space and covering the electrode assembly 3. The insulating film 4 includes a bottom insulating layer 4-1 and a side insulating layer 4-2. Multiple bottom insulating layers 4-1 are stacked on the bottom of the electrode assembly 3, and at least one side insulating layer 4-2 is provided on each side of the electrode assembly 3. Each bottom insulating layer 4-1 and the side insulating layer 4-2 are integrally formed and connected.

[0025] like Figure 1 The figure shows a cross-sectional schematic diagram of a battery cell along the height direction. The battery cell includes a connected cover plate assembly 1 and a housing 2, forming an internal receiving space. An electrode assembly 3 is disposed in the receiving space. In the figure, the L direction is the length direction of the electrode assembly 3, and the H direction is the height direction of the electrode assembly 3.

[0026] The surface of electrode assembly 3 is covered with an insulating film 4, which serves to bind and insulate the electrode. For example... Figure 1 As shown, the insulating film 4 includes a bottom insulating layer 4-1 and a side insulating layer 4-2. The bottom of the electrode assembly 3 is provided with three layers of bottom insulating layer 4-1, and each side of the electrode assembly 3 is provided with a side insulating layer 4-2. In this way, the overall thickness of the bottom insulating layer of the electrode assembly 3 is greater than the overall thickness of the side insulating layer. The extra bottom insulating layer 4-1 can act as a bottom support plate, thereby improving the protection effect on the bottom of the electrode assembly 3 and preventing the cell from short-circuiting or being mechanically damaged.

[0027] Each bottom insulating layer 4-1 and side insulating layer 4-2 are integrally formed and connected, which is more stable than the bottom support plate with heat fusion connection, and is not easy to fall off under the influence of external force, thus providing good protection for the electrode assembly 3. The integrally formed bottom insulating layer 4-1 and side insulating layer 4-2 can be obtained by cutting the same insulating film 4, which reduces the manufacturing difficulty compared to the heat fusion process. Using the bottom insulating layer 4-1 instead of the bottom support plate structure can also reduce production costs.

[0028] The battery cell has a simple structure, is easy to manufacture, and has strong stability, which can prevent the battery cell from short-circuiting or being mechanically damaged.

[0029] In some embodiments, the side insulating layer 4-2 includes a first side insulating layer 4-21 and a second side insulating layer 4-22 integrally formed and connected. The first side insulating layer 4-21 abuts against the sidewalls of the electrode assembly 3 opposite to each other along its thickness direction, and the second side insulating layer 4-22 abuts against the sidewalls of the electrode assembly 3 opposite to each other along its length direction. The bottom insulating layer 4-1 includes a first bottom insulating layer 4-11 and a second bottom insulating layer 4-12 integrally formed and connected to the first side insulating layer 4-21, and the second bottom insulating layer 4-12 is integrally formed and connected to the second side insulating layer 4-22.

[0030] like Figure 2 The diagram shown is a schematic representation of the unfolded state of an insulating film 4. Figure 3 The diagram shows a schematic of the structure of the insulating film 4 enclosing the electrode assembly 3, where the T direction is the thickness direction of the electrode assembly 3.

[0031] The side insulating layer 4-2 includes an integrally formed first side insulating layer 4-21 and a second side insulating layer 4-22. The first side insulating layer 4-21 abuts against the sidewall of the electrode assembly 3 along its thickness direction and is used to wrap the large side of the electrode assembly 3. The second side insulating layer 4-22 abuts against the sidewall of the electrode assembly 3 along its length direction and is used to wrap the small side of the electrode assembly 3.

[0032] like Figure 2 As shown, the first side insulating layer 4-21 and the second side insulating layer 4-22 are alternately connected, and the whole can completely wrap the side of the electrode assembly 3. The side insulating layer 4-2 includes two first side insulating layers 4-21 and at least two second side insulating layers 4-22. One small side of the electrode assembly 3 is wrapped by one second side insulating layer 4-22, and the other small side can be wrapped by one or two second side insulating layers 4-22, which is not limited in specific terms.

[0033] The bottom insulating layer 4-1 includes a first bottom insulating layer 4-11 and a second bottom insulating layer 4-12. Both the first bottom insulating layer 4-11 and the second bottom insulating layer 4-12 are used to wrap the bottom of the electrode assembly 3. The difference is that the first bottom insulating layer 4-11 is integrally formed and connected to the first side insulating layer 4-21, and the second bottom insulating layer 4-12 is integrally formed and connected to the second side insulating layer 4-22, which facilitates cutting them together. The long side of the first bottom insulating layer 4-11 is connected to the bottom long side of the first side insulating layer 4-21, and the short side of the second bottom insulating layer 4-12 is connected to the bottom short side of the first side insulating layer 4-21.

[0034] In some embodiments, the bottom insulating layer 4-1 includes two first bottom insulating layers 4-11 and one second bottom insulating layer 4-12, with the two first bottom insulating layers 4-11 located between the second bottom insulating layer 4-12 and the electrode assembly 3.

[0035] like Figure 2 As shown, the bottom insulating layer 4-1 includes two first bottom insulating layers 4-11 and one second bottom insulating layer 4-12. When the bottom insulating layer 4-1 wraps the electrode assembly 3, as... Figure 3 As shown, two layers of first bottom insulating layer 4-11 can be placed between the second bottom insulating layer 4-12 and the electrode assembly 3. In this way, the second bottom insulating layer 4-12 can directly wrap the first bottom insulating layer 4-11. Only the second bottom insulating layer 4-12 needs to be fixed, and the first bottom insulating layer 4-11 does not need to be fixed separately, which can reduce manufacturing costs. The second bottom insulating layer 4-12 can be fixed to the bottom of the electrode assembly 3 by adhesive or heat fusion, and there is no specific limitation.

[0036] In some embodiments, the length of the first bottom insulating layer 4-11 is equal to the length of the electrode assembly 3, and the width is greater than or equal to 1 / 2 of the thickness of the electrode assembly 3.

[0037] like Figure 2 and Figure 3 As shown, the length of the first bottom insulating layer 4-11 is equal to the length of the electrode assembly 3, so that the long side of the first bottom insulating layer 4-11 can wrap around the bottom long side of the electrode assembly 3 to ensure the isolation effect; the width of the first bottom insulating layer 4-11 is greater than or equal to 1 / 2 of the thickness of the electrode assembly 3. For example, the width of the first bottom insulating layer 4-11 is 1 / 2, 2 / 3, 4 / 5 or 1 times the thickness of the electrode assembly 3, etc., and there is no specific limitation, because the insulating film 4 includes two first bottom insulating layers 4-11 arranged opposite to each other. This can ensure that the two first bottom insulating layers 4-11 completely wrap around the bottom of the electrode assembly 3 to ensure the isolation effect.

[0038] In some embodiments, the width of the first bottom insulating layer 4-11 is equal to the thickness of the electrode assembly 3.

[0039] like Figure 2 As shown, the width of the first bottom insulating layer 4-11 is equal to the thickness of the electrode assembly 3. In this way, one first bottom insulating layer 4-11 can completely cover the bottom of the electrode assembly 3. The stacking of two first bottom insulating layers 4-11 is equivalent to increasing the overall thickness of the insulating structure at the bottom of the electrode assembly 3, thereby further improving the insulation effect.

[0040] In some embodiments, the length of the second bottom insulating layer 4-12 is equal to the length of the electrode assembly 3, and the width is equal to the thickness of the electrode assembly 3.

[0041] like Figure 2 and Figure 3 As shown, the length of the second bottom insulating layer 4-12 is equal to the length of the electrode assembly 3, and the width is equal to the thickness of the electrode assembly 3. In this way, the second bottom insulating layer 4-12 can completely wrap the bottom of the electrode assembly 3, and can also wrap the two first bottom insulating layers 4-11 to ensure the isolation effect.

[0042] In some embodiments, the side insulating layer 4-2 further includes a third side insulating layer 4-23, which is integrally formed and connected to the second bottom insulating layer 4-12 and abuts against the second side insulating layer 4-22.

[0043] like Figure 2 As shown, the end of the second bottom insulating layer 4-12 away from the second side insulating layer 4-22 is connected to a third side insulating layer 4-23. Thus, after the second bottom insulating layer 4-12 wraps around the first bottom insulating layer 4-11, as... Figure 3 As shown, the third side insulating layer 4-23 can be bonded to the corresponding second side insulating layer 4-22 and then fixed. The fixing method is, for example, hot melting, bonding, etc., or adhesive can be applied to the outer side of the second side insulating layer 4-22 and the third side insulating layer 4-23. The specific method is not limited. This makes the fixing position of the insulating film 4 concentrated on the small side of the electrode assembly 3, while the bottom insulating layer 4-1 does not need to be fixed, making the bottom of the electrode assembly 3 more stable.

[0044] In some embodiments, the height of the third side insulating layer 4-23 is less than or equal to the height of the electrode assembly 3.

[0045] like Figure 3 As shown, the height of the third side insulating layer 4-23 is less than or equal to the height of the electrode assembly 3. For example, the height of the third side insulating layer 4-23 is 1 / 4, 1 / 3, 1 / 2, 2 / 3 or 1 times the height of the electrode assembly 3, etc., without being limited to any specific value, to ensure the wrapping and fixing effect of the insulating film 4, while saving materials.

[0046] In some embodiments, each bottom insulating layer 4-1 is provided with an impregnation hole 4-3, and the impregnation holes 4-3 on two adjacent bottom insulating layers 4-1 do not overlap in the orthographic projection of the bottom of the housing 2.

[0047] like Figure 1As shown, each bottom insulating layer 4-1 is provided with wetting holes 4-3, which can improve the wetting effect of the bottom electrolyte on the electrode assembly 3. The wetting holes 4-3 on adjacent bottom insulating layers 4-1 are arranged so that their orthographic projections on the bottom of the housing 2 do not overlap. For example, the wetting holes 4-3 on different bottom insulating layers 4-1 are staggered. This provides a wetting channel for the electrolyte while ensuring insulation and preventing the electrode assembly 3 from contacting the housing 2.

[0048] In some embodiments of this application, a secondary battery is provided, including the battery cell as described in any of the above embodiments. The secondary battery can be applied to electrical devices, such as vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles. Spacecraft include airplanes, rockets, space shuttles, and spacecraft. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers.

[0049] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in the details for the sake of brevity.

[0050] Furthermore, given that details have been set forth to describe exemplary embodiments of this application, it will be apparent to those skilled in the art that embodiments of this application may be practiced without these details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0051] Although this application has been described in conjunction with embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0052] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. An electric cell, characterized by, The application relates to a battery cell, comprising: a cover plate assembly; a shell cooperating with the cover plate assembly to form a containing space; an electrode assembly arranged in the containing space; an insulation film arranged in the containing space and covering the electrode assembly, the insulation film comprising a bottom insulation layer and a side insulation layer, the bottom layer of the electrode assembly being arranged with a plurality of layers of the bottom insulation layer, each side of the electrode assembly being provided with at least one side insulation layer, and each layer of the bottom insulation layer being integrally connected with the side insulation layer.

2. The electric cell of claim 1, wherein, The side insulation layer comprises a first side insulation layer and a second side insulation layer which are integrally connected, the first side insulation layer abutting against the side wall of the electrode assembly in the thickness direction, and the second side insulation layer abutting against the side wall of the electrode assembly in the length direction. The bottom insulation layer comprises a first bottom insulation layer and a second bottom insulation layer, the first bottom insulation layer being integrally connected with the first side insulation layer, and the second bottom insulation layer being integrally connected with the second side insulation layer.

3. The electric cell of claim 2, wherein, The bottom insulation layer comprises two layers of the first bottom insulation layer and one layer of the second bottom insulation layer, and the two layers of the first bottom insulation layer are arranged between the second bottom insulation layer and the electrode assembly.

4. The electric cell of claim 2, wherein, The length of the first bottom insulation layer is equal to the length of the electrode assembly, and the width of the first bottom insulation layer is greater than or equal to 1 / 2 of the thickness of the electrode assembly.

5. The electric cell of claim 4, wherein, The width of the first bottom insulation layer is equal to the thickness of the electrode assembly.

6. The electric cell of claim 2, wherein, The length of the second bottom insulation layer is equal to the length of the electrode assembly, and the width of the second bottom insulation layer is equal to the thickness of the electrode assembly.

7. The electric cell of claim 2, wherein, The side insulation layer further comprises a third side insulation layer which is integrally connected with the second bottom insulation layer and abuts against the second side insulation layer.

8. The electric cell of claim 7, wherein, The height of the third side insulation layer is less than or equal to the height of the electrode assembly.

9. The electric cell of claim 1, wherein, Each layer of the bottom insulation layer is provided with an infiltration hole, and the infiltration holes on two adjacent layers of the bottom insulation layer do not overlap in the bottom orthographic projection of the shell.

10. A secondary battery characterized by comprising: The application further relates to a battery cell comprising the battery cell as claimed in any one of claims 1 to 9.

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