Single battery

Abstract

The utility model provides a single battery. The single battery comprises a shell; the electrode assembly is positioned in the shell; an insulating film between the case and the electrode assembly to insulate the case and the electrode assembly; the insulating film comprises a first insulating part wrapping the side surface of the electrode assembly and a second insulating part covering the bottom surface of the electrode assembly, and the second insulating part is provided with at least two positioning holes; the bottom supporting plate is located between the shell and the bottom of the second insulating part; at least two positioning protrusions are arranged on the top of the bottom supporting plate in a protruding mode, and each positioning protrusion is correspondingly embedded in one positioning hole. The positioning protrusions are arranged at the top of the bottom supporting plate and embedded in the positioning holes, so that the blocking effect and the insulating performance of the bottom supporting plate and the insulating film between the shell and the electrode assembly can be improved, and the packaging effect of the single battery is guaranteed.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more particularly to a single-cell battery. Background Technology

[0002] In a single cell, the Mylar film (polyester insulating film) is usually wrapped around the surface of the electrode assembly to isolate the electrode assembly from the housing, prevent them from coming into contact and causing a short circuit, and reduce the risk of scratches during assembly.

[0003] In related technologies, the Mylar membrane is typically used in conjunction with a base plate, and the Mylar membrane and the base plate are connected and positioned through positioning holes. However, the presence of positioning holes reduces the barrier effect of the Mylar membrane and the base plate on the electrode components and the housing, which can easily lead to micro-short circuits between them. This not only accelerates the corrosion of the housing but may also cause problems such as battery cell encapsulation failure. Utility Model Content

[0004] In view of this, the purpose of this application is to propose a single-cell battery to solve some or all of the aforementioned technical problems.

[0005] For the purposes described above, this application provides a single-cell battery, comprising:

[0006] case;

[0007] The electrode assembly is located within the housing;

[0008] An insulating film is located between the housing and the electrode assembly to insulate the housing and the electrode assembly; the insulating film includes a first insulating portion wrapped around the side of the electrode assembly and a second insulating portion covering the bottom surface of the electrode assembly, the second insulating portion having at least two positioning holes;

[0009] A base plate is located between the housing and the bottom of the second insulating part; the top of the base plate is provided with at least two positioning protrusions, and each positioning protrusion is correspondingly embedded in a positioning hole.

[0010] As can be seen from the above, this application provides a single-cell battery. By providing a positioning protrusion on the top of the base plate and embedding the protrusion into the positioning hole during the single-cell battery assembly process, the barrier effect and insulation performance between the base plate and the insulating film on the casing and electrode components can be improved, reducing the corrosion of the casing by the electrolyte and ensuring the encapsulation performance of the single-cell battery. Furthermore, using positioning holes and positioning protrusions for positioning connection can also reduce the assembly difficulty between the insulating film and the base plate, improve the positioning accuracy between them, and increase the assembly efficiency of the single-cell battery while ensuring product quality. Attached Figure Description

[0011] 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.

[0012] Figure 1 This is a schematic diagram of a single battery cell in an embodiment of this application;

[0013] Figure 2 This is a schematic diagram showing the connection between the electrode assembly and the insulating film in an embodiment of this application;

[0014] Figure 3 This is a schematic diagram showing the connection between the first type of positioning hole and the positioning protrusion in an embodiment of this application;

[0015] Figure 4 This is a schematic diagram showing the connection between the second type of positioning hole and the positioning protrusion in an embodiment of this application;

[0016] Figure 5 This is a top view of the first type of base plate in the embodiments of this application;

[0017] Figure 6 This is a top view of the second type of base plate in the embodiments of this application;

[0018] Figure 7 This is a schematic diagram showing the unfolded insulating film in an embodiment of this application.

[0019] Explanation of reference numerals in the attached figures

[0020] 1. Housing; 101. Cover assembly; 102. Electrode terminals;

[0021] 2. Electrode assembly;

[0022] 3. Insulating film; 301. First insulating part; 3011. Covering part; 3012. Connecting part; 302. Second insulating part; 3021. Positioning hole; 310. First crease; 320. Second crease;

[0023] 4. Base plate; 401. Positioning protrusion. Detailed Implementation

[0024] 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.

[0025] 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.

[0026] The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0027] Mylar membranes are an important component of single-cell batteries, such as prismatic cells. Due to their excellent insulation and barrier properties, mylar membranes can be used as insulating films to wrap the surface of electrode components, achieving both protection and insulation. During the assembly of single-cell batteries, the mylar membrane wrapped around the electrode components not only protects them from scratches by the edges of the casing but also isolates the casing from the electrode components after they are installed inside, preventing short circuits caused by electrical conductivity between the electrode components and the casing.

[0028] In addition, a base plate is provided at the bottom of the Mylar membrane to support and protect the bottom surface of the electrode assembly. To achieve the positioning connection between the Mylar membrane and the base plate, corresponding positioning holes are provided on the bottom of both the Mylar membrane and the base plate. The positioning holes are used to position the assembly and then use a hot-melt process to fix the two together. However, the presence of positioning holes will affect the barrier performance between the Mylar membrane and the base plate, and may easily form a channel structure between the electrode assembly and the housing. This will weaken the electrical isolation effect of the electrode assembly at the positioning holes. If there are conductive foreign objects in the housing, it may cause the two to conduct to each other and cause micro-short circuit problems. This will not only increase the corrosion rate of the housing by the electrolyte, but may also cause problems such as the failure of the battery cell encapsulation.

[0029] In view of this, this application provides a single-cell battery, combined with Figures 1-7 The content shown provides a detailed description of this single battery cell.

[0030] A single-cell battery includes a housing 1, an electrode assembly 2, an insulating film 3, and a base plate 4. The electrode assembly 2 is located inside the housing 1. The insulating film 3 is located between the housing 1 and the electrode assembly 2 to insulate the housing 1 and the electrode assembly 2. The insulating film 3 includes a first insulating portion 301 wrapped around the side of the electrode assembly 2 and a second insulating portion 302 covering the bottom surface of the electrode assembly 2. The second insulating portion 302 has at least two positioning holes 3021. The base plate 4 is located between the housing 1 and the bottom of the second insulating portion 302. The top of the base plate 4 has at least two positioning protrusions 401, each positioning protrusion 401 being correspondingly embedded in a positioning hole 3021.

[0031] Specifically, Figure 1 This is a schematic diagram of a single battery cell in an embodiment of this application. Figure 2 This is a schematic diagram showing the connection between the electrode assembly 2 and the insulating film 3 in an embodiment of this application.

[0032] Specifically, the housing 1 has a cavity, through which the housing 1 can accommodate the electrolyte, as well as components such as the electrode assembly 2, the insulating film 3, and the base plate 4.

[0033] For example, the housing 1 may be formed of aluminum and related alloys, which are strong and lightweight.

[0034] For example, the inner surface of the housing 1 may be coated with a chemically stable, corrosion-resistant and insulating coating such as polyurethane or ceramic coating, which can extend the service life of the housing 1.

[0035] Furthermore, such as Figure 1 and Figure 2 As shown, the top of the housing 1 can be connected to a cover plate assembly 101 for sealing the cavity, so as to seal the cavity and form a stable electrochemical environment inside it; the cover plate assembly 101 is provided with an electrode terminal 102, which can be electrically connected to the electrode assembly 2 inside the cavity, and is also used to establish an electrical connection with external electrical equipment.

[0036] Furthermore, the cover assembly 101 may be provided with an explosion-proof component for releasing high-temperature and high-pressure gases and ejected materials during thermal runaway of a single cell, as well as an injection hole for injecting electrolyte into the single cell.

[0037] Specifically, such as Figure 2As shown, since the housing 1 has a cavity, the electrode assembly 2 can be housed within the housing 1 so that the electrode assembly 2 is immersed in the electrolyte and stores and releases energy through a chemical reaction. More specifically, the electrode assembly 2 may include alternately stacked positive and negative electrode plates, and a diaphragm for isolating the positive and negative electrode plates. The positive electrode plates, negative electrode plates, and diaphragm are wound to form a core structure, and the positive and negative electrode plates extend tabs of different polarities, which are electrically connected to different electrode terminals 102 respectively. The diaphragm allows ions in the electrolyte to migrate freely during the electro-circulation process to prevent the positive and negative electrode plates from contacting each other and causing a short circuit.

[0038] Specifically, Figure 3 This is a schematic diagram showing the connection between the first type of positioning hole 3021 and the positioning protrusion 401 in an embodiment of this application. Figure 4 This is a schematic diagram showing the connection between the second type of positioning hole 3021 and the positioning protrusion 401 in an embodiment of this application. Figure 5 This is a top view of the first type of base plate 4 in the embodiments of this application. Figure 6 This is a top view of the second type of base plate 4 in this embodiment of the application. Figure 7 This is a schematic diagram showing the unfolded state of the insulating film 3 in an embodiment of this application.

[0039] Specifically, such as Figures 2-7 As shown, the insulating film 3 of the single cell is located between the housing 1 and the electrode assembly 2, and can be used to block the housing 1 and the electrode assembly 2 to achieve electrical insulation. The insulating film 3 includes a first insulating part 301 wrapped around the side of the electrode assembly 2 to wrap the circumferential side of the electrode assembly 2, thereby forming effective protection for the side of the electrode assembly 2. The insulating film 3 also includes a second insulating part 302 covering the bottom surface of the electrode assembly 2, which can effectively protect the bottom surface of the electrode assembly 2 to prevent short circuit caused by conduction between the electrode assembly 2 and the housing 1.

[0040] Specifically, such as Figures 3-7 As shown, a base plate 4 for supporting the electrode assembly 2 is provided between the bottom of the insulating film 3 and the housing 1. At this time, by providing a positioning hole 3021 in the second insulating part 302 and a positioning protrusion 401 on the top of the base plate 4, the positioning protrusion 401 of the base plate 4 can be embedded in the positioning hole 3021 of the second insulating part 302 during the assembly of the single cell, thereby accurately installing the base plate 4 on the bottom surface of the second insulating part 302 of the insulating film 3 and realizing rapid assembly between the two. By using the positioning hole 3021 and the positioning protrusion 401 to position and connect the insulating film 3 and the base plate 4, the positioning connection accuracy and assembly speed between the two can be improved, while also reducing the difficulty of positioning connection. This helps to improve the assembly efficiency of the single cell while ensuring product quality.

[0041] In addition, after the bottom plate 4 and the second insulating part 302 are assembled through the positioning protrusion 401 and the positioning hole 3021, the bottom plate 4 can block the positioning hole 3021 of the second insulating part 302. This reduces the probability of foreign objects inside the housing 1 entering the positioning hole 3021, thereby avoiding micro-short circuit problems caused by foreign objects between the electrode assembly 2 and the housing 1, ensuring the working performance of the single cell, slowing down the corrosion rate of the electrolyte on the housing 1, and ensuring the encapsulation performance of the single cell.

[0042] In some embodiments, in the thickness direction of the base plate 4, the height of the positioning protrusion 401 is less than the thickness of the second insulating portion 302.

[0043] Specifically, such as Figure 3 and Figure 4 As shown, by utilizing the positioning protrusion 401 provided on the base plate 4 and the positioning hole 3021 opened in the second insulating part 302, the assembly efficiency of the base plate 4 and the insulating film 3 can be accelerated and the positioning accuracy between them can be improved. In particular, by making the height of the positioning protrusion 401 less than the thickness of the second insulating part 302 in the thickness direction of the base plate 4, it can be avoided that the positioning protrusion 401 will not form a protruding structure on the top surface of the second insulating part 302 after being embedded in the positioning hole 3021, so as to ensure that the second insulating part 302 can fully cover the bottom surface of the electrode assembly 2, and ensure the coverage effect of the second insulating part 302 on the bottom surface of the electrode assembly 2.

[0044] For example, in the thickness direction of the base plate 4, the height of the positioning protrusion 401 can be set within the range of 0.2-0.5mm, ensuring that the positioning protrusion 401 and the positioning hole 3021 have a good positioning effect, while not causing a large change in the thickness of the second insulating part 302.

[0045] For example, the positioning hole 3021 can be a through hole, which can reduce the difficulty of opening the positioning hole 3021 on the second insulating part 302, thereby reducing the cost of the single cell.

[0046] For example, the positioning hole 3021 can be a blind hole, and the blind hole can be opened on the side of the second insulating part 302 near the bottom plate 4, which can improve the barrier effect of the second insulating part 302 on the electrode assembly 2 and the housing 1. It should be noted that in order to ensure the strength of the area where the positioning hole 3021 is located, the thickness of the second insulating part 302 can be appropriately increased to ensure the barrier effect of the second insulating part 302.

[0047] In some embodiments, the positioning protrusion 401 has a circular cross-section perpendicular to the thickness direction of the base plate 4, and is adapted to the corresponding positioning hole 3021.

[0048] Specifically, such as Figure 5 and Figure 6As shown, for the positioning protrusion 401, by setting the cross-section of the positioning protrusion 401 perpendicular to the thickness direction of the base plate 4 to be circular, the positioning protrusion 401 has a columnar structure and is adapted to the corresponding positioning hole 3021. This reduces the difficulty of forming the positioning protrusion 401 on the top of the base plate 4 and ensures the reliability of the connection between the first insulating part 301 and the base plate 4 after assembly.

[0049] Furthermore, the positioning protrusion 401 and the base plate 4 can be formed using an integral molding process.

[0050] Furthermore, the diameter difference between the cross-sections of the positioning hole 3021 and the positioning protrusion 401 is within the range of 0.1mm-1mm. Specifically, by controlling the diameter difference between the cross-sections of the positioning hole 3021 and the positioning protrusion 401 within the range of 0.1mm-1mm, on the one hand, setting the diameter difference between the two to be above 0.1mm can improve the fit between the positioning protrusion 401 and the positioning hole 3021, making it easier for the positioning protrusion 401 to be embedded inside the positioning hole 3021; ​​on the other hand, setting the diameter difference between the two to be below 1mm can avoid reducing the firmness after assembly due to excessive size difference, so as to prevent the base plate 4 and the second insulating part 302 from shifting or misaligning and affecting the positioning accuracy.

[0051] In some embodiments, the cross-section of the positioning protrusion 401 perpendicular to the thickness direction of the base plate 4 is any one of polygon, strip, fan shape and ellipse, and is adapted to the corresponding positioning hole 3021.

[0052] Specifically, the shape of the positioning protrusion 401 can be flexibly selected according to actual process requirements. For the positioning protrusion 401, the cross-section of the positioning protrusion 401 perpendicular to the thickness direction of the base plate 4 can be set to any shape among polygons, strips, fan shapes and ellipses, so that the positioning protrusion 401 forms a columnar structure such as a prism or elliptical cylinder, which can also ensure the reliability of the connection between the first insulating part 301 and the base plate 4 after assembly.

[0053] In some embodiments, there is a gap between the edge of the positioning hole 3021 and the edge of the second insulating portion 302. For example... Figure 7 As shown, for the positioning hole 3021, by setting a corresponding gap between the edge of the positioning hole 3021 and the edge of the second insulating portion 302, the integrity of the positioning hole 3021 on the second insulating film 3 can be ensured, so that the positioning protrusion 401 and the positioning hole 3021 can be fully fitted. More specifically, since the thickness of the second insulating portion 302 is relatively thin, by leaving a gap between the edge of the positioning hole 3021 and the edge of the second insulating portion 302, problems such as tearing or damage to the edge of the positioning hole 3021 can be avoided.

[0054] In some embodiments, the orthographic projection of the positioning protrusion 401 onto the base plate 4 is located within the base plate 4.

[0055] Specifically, such as Figure 5 and Figure 6 As shown, when the orthographic projection of the positioning protrusion 401 on the base plate 4 is located inside the base plate 4, the positioning protrusion 401 on the top of the base plate 4 can be embedded into the positioning hole 3021 of the second insulating part 302. The edge of the base plate 4 can block the edge of the positioning hole 3021, thereby improving the barrier effect of the base plate 4 and the insulating film 3 on the housing 1 and the electrode assembly 2.

[0056] In some embodiments, two positioning protrusions 401 are provided, and the two positioning protrusions 401 are symmetrically distributed with respect to the central region of the base plate 4 in the length direction of the base plate 4.

[0057] Specifically, such as Figure 5 As shown, regarding the positioning protrusions 401, when two positioning protrusions 401 are provided on the top of the base plate 4, the number of positioning protrusions 401 can be controlled to reduce the complexity of the base plate 4, provided that the second insulating part 302 and the base plate 4 are accurately positioned. This allows the base plate 4 to be suitable for single cells of different specifications. More specifically, along the length direction of the base plate 4, by symmetrically distributing the two positioning protrusions 401 relative to the central area of ​​the base plate 4, the opposite ends of the base plate 4 can be positioned respectively, ensuring that the assembled base plate 4 has good stability.

[0058] Furthermore, such as Figure 6 As shown, the top of the base plate 4 can also be provided with three or more positioning protrusions 401. Correspondingly, the second insulating part 302 is provided with positioning holes 3021 that are compatible with the positioning holes 3021. This can further increase the positioning accuracy between the base plate 4 and the insulating film 3 and the reliability after assembly.

[0059] In some embodiments, the first insulating portion 301 includes two covering portions 3011; wherein, in the width direction of the base plate 4, the two covering portions 3011 are respectively connected to the opposite sides of the second insulating portion 302.

[0060] Specifically, such as Figure 2 and Figure 7As shown, in the width direction of the base plate 4, by providing foldable covering portions 3011 on opposite sides of the second insulating portion 302, the assembly difficulty between the electrode assembly 2 and the insulating film 3 can be reduced; more specifically, when the two covering portions 3011 are folded and cover opposite sides of the electrode assembly 2, the two covering portions 3011 can fully cover both sides of the electrode assembly 2 to protect the opposite sides of the electrode assembly 2.

[0061] In some embodiments, in the length direction of the base plate 4, connecting portions 3012 extend from opposite sides of each covering portion 3011, and the two covering portions 3011 are connected by corresponding connecting portions 3012.

[0062] Specifically, such as Figure 2 and Figure 7 As shown, the two covering portions 3011 in the first insulating portion 301 can protect the two opposite sides of the electrode assembly 2. Therefore, by extending connecting portions 3012 from the opposite sides of each covering portion 3011, the multiple connecting portions 3012 can shield and insulate the other two opposite sides of the electrode assembly 2 during the assembly of the electrode assembly 2 and the insulating film 3. At the same time, since the two covering portions 3011 are connected by corresponding connecting portions 3012, the insulating film 3 can fully cover the surface of the electrode assembly 2 to ensure the insulation and protection performance of the insulating film 3 for the electrode assembly 2.

[0063] For example, when the electrode assembly 2 is wrapped with the insulating film 3, the covering part 3011 and the connecting part 3012 can be folded toward the direction close to the electrode assembly 2, so that the first covering layer and the second insulating part 302, and the covering part 3011 and the connecting part 3012 form 90° angles respectively. After the corresponding connecting parts 3012 are connected with adhesive, the first insulating part 301 and the second insulating part 302 can be enclosed to form a shell structure with an opening. When the electrode assembly 2 is located inside the shell structure, the shell structure can cover the bottom and sides of the electrode assembly 2, thereby achieving the purpose of electrical insulation and protection of the electrode assembly 2.

[0064] In some embodiments, a first crease 310 is provided between the second insulating portion 302 and the covering portion 3011, the first crease 310 extending in the length direction of the base plate 4; and / or a second crease 320 is provided between the covering portion 3011 and the connecting portion 3012, the second crease 320 extending in a direction perpendicular to the extending direction of the first crease 310.

[0065] Specifically, such as Figure 2 and Figure 7As shown, by providing a first crease 310 between the second insulating part 302 and the covering part 3011, and extending the first crease 310 in the length direction of the base plate 4, the difficulty and constraint of folding between the second insulating part 302 and the covering part 3011 can be reduced, so that the second insulating part 302 and the covering part 3011 can better cover the surface of the electrode assembly 2.

[0066] Similarly, by providing a second crease 320 between the covering portion 3011 and the connecting portion 3012, and making the extension direction of the second crease 320 perpendicular to the extension direction of the second crease 320, the folding difficulty and constraint between the covering portion 3011 and the connecting portion 3012 can be reduced, thereby enabling the covering portion 3011 and the connecting portion 3012 to better cover the side of the electrode assembly 2. At the same time, it can also improve the wrapping strength of the insulating film 3 on the surface of the electrode assembly 2, ensuring the protective effect and insulation performance of the insulating film 3 on the electrode assembly 2.

[0067] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0068] The various embodiments in this application are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0069] The description in this application is given for illustrative purposes and is not intended to be exhaustive or to limit the application to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of this application and to enable those skilled in the art to understand this application and design various embodiments with various modifications suitable for a particular purpose.

[0070] 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.

[0071] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0072] 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. A single cell, characterized by, include: case; The electrode assembly is located within the housing; An insulating film is located between the housing and the electrode assembly to insulate the housing and the electrode assembly; the insulating film includes a first insulating portion wrapped around the side of the electrode assembly and a second insulating portion covering the bottom surface of the electrode assembly, the second insulating portion having at least two positioning holes; A base plate is located between the housing and the bottom of the second insulating part; the top of the base plate is provided with at least two positioning protrusions, and each positioning protrusion is correspondingly embedded in a positioning hole.

2. The cell according to claim 1, wherein In the thickness direction of the base plate, the height of the positioning protrusion is less than the thickness of the second insulating part.

3. The cell according to claim 1, wherein The positioning protrusion has a circular cross-section perpendicular to the thickness direction of the base plate and is adapted to the corresponding positioning hole. The diameter difference between the cross-section of the positioning hole and the positioning protrusion is within the range of 0.1mm-1mm.

4. The cell according to claim 1, wherein The cross-section of the positioning protrusion perpendicular to the thickness direction of the base plate is any one of polygon, strip, fan shape, and ellipse, and is adapted to the corresponding positioning hole.

5. The cell according to claim 1, wherein There is a gap between the edge of the positioning hole and the edge of the second insulating part.

6. The cell according to claim 1, wherein The positioning protrusion is projected onto the base plate and lies within the base plate.

7. The cell according to claim 1, wherein Two positioning protrusions are provided, and the two positioning protrusions are symmetrically distributed with respect to the central area of ​​the base plate along the length direction of the base plate.

8. The cell according to claim 1, wherein The first insulating part includes: Two covering portions are respectively connected to opposite sides of the second insulating portion in the width direction of the base plate.

9. The cell according to claim 8, wherein Along the length of the base plate, connecting portions extend from opposite sides of each of the covering portions, and two covering portions are connected by corresponding connecting portions.

10. The cell according to claim 9, wherein A first crease is provided between the second insulating portion and the covering portion, the first crease extending along the length of the base plate; and / or, A second crease is provided between the covering part and the connecting part, and the extension direction of the second crease is perpendicular to the extension direction of the first crease.

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