Battery monomer and electric equipment

Abstract

The utility model relates to a battery monomer and electric equipment. The battery cell includes: a case; the battery cell is positioned in the shell; the insulating film comprises a side wall coating sheet and a first connecting component; the side wall coating sheet covers the peripheral wall of the battery cell so as to separate the battery cell from the shell; the side wall coating sheet comprises a first end and a second end which are oppositely arranged in the circumferential direction; the first connecting assembly comprises a first connecting piece and a second connecting piece; the first connecting piece comprises a first hard part, and the second connecting piece comprises a second hard part and a first elastic part; the first elastic part is connected with the first end of the side wall wrapping piece and the second hard part, the first hard part is connected with the second end of the side wall wrapping piece, and the first hard part and the second hard part are connected in a clamped mode. According to the technical scheme, the process cost is reduced.

Description

Technical Field

[0001] This application relates to the field of batteries, and in particular to a battery cell and an electrical device. Background Technology

[0002] Lithium-ion batteries are a type of battery that uses lithium metal or lithium alloys as positive / negative electrode materials and a non-aqueous electrolyte solution. Lithium-ion batteries have advantages such as high energy density, high operating voltage, long cycle life, fast charging capability, low self-discharge rate, no memory effect, and strong adaptability to high and low temperatures. However, under abnormal conditions, lithium-ion batteries may experience short circuits or explosions due to overheating, posing certain safety risks.

[0003] Therefore, the safety of lithium batteries has always been one of the top priorities for manufacturers. Installing an insulating or protective film between the cell and the casing is one measure to improve the safety of lithium batteries.

[0004] However, current insulating films generally require a hot-melt process to wrap the battery cell, which results in relatively high processing costs. Utility Model Content

[0005] In view of this, this application provides a battery cell and an electrical device to solve at least one problem existing in the prior art.

[0006] To achieve the above objectives, the technical solution of this application is implemented as follows:

[0007] In a first aspect, embodiments of this application provide a single battery cell, comprising:

[0008] case;

[0009] The battery cell is located inside the housing;

[0010] An insulating film, including a sidewall covering sheet and a first connecting assembly;

[0011] The sidewall covering sheet covers the outer peripheral wall of the battery cell to separate the battery cell from the housing; the sidewall covering sheet includes a first end and a second end disposed opposite to each other along its circumference;

[0012] The first connecting component includes a first connector and a second connector; the first connector includes a first rigid portion, and the second connector includes a second rigid portion and a first elastic portion; the first elastic portion connects a first end of the sidewall covering sheet and the second rigid portion, the first rigid portion connects a second end of the sidewall covering sheet, and the first rigid portion and the second rigid portion are engaged.

[0013] In conjunction with a first aspect of the embodiments of this application, in an optional embodiment, one of the first rigid portion and the second rigid portion has a snap fastener, and the other has a slot that engages with the snap fastener.

[0014] In conjunction with a first aspect of the embodiments of this application, in an optional embodiment, the insulating film further includes:

[0015] A bottom support plate covers the bottom of the battery cell; the bottom support plate is in contact with the sidewall covering plate.

[0016] In conjunction with a first aspect of the embodiments of this application, in an optional embodiment, the sidewall covering sheet is made of a single sheet of insulating material, and the sidewall covering sheet and the first elastic portion are integrally formed.

[0017] In an optional embodiment, in conjunction with a first aspect of the embodiments of this application, the sidewall covering sheet includes a first covering portion, a second covering portion, and a second connecting assembly. The first covering portion and the second covering portion are respectively located on both sides of the thickness direction of the battery cell. The first covering portion has a first end and a third end disposed opposite to each other along the length direction of the battery cell, and the second covering portion has a second end and a fourth end disposed opposite to each other along the length direction of the battery cell. A second connecting assembly is disposed between the third end of the first covering portion and the fourth end of the second covering portion. The second connecting assembly includes a third connector and a fourth connector. The third connector includes a third rigid portion, and the fourth connector includes a fourth rigid portion and a second elastic portion. One end of the third end and the fourth end are connected to the third rigid portion, and the other end is connected to the fourth rigid portion through the second elastic portion. The fourth rigid portion and the third rigid portion are engaged.

[0018] In conjunction with a first aspect of the embodiments of this application, in an optional embodiment, the first end of the first covering portion and the first rigid portion are integrally formed, the third end of the first covering portion and the second elastic portion are thermally fused together, and the fourth end of the second covering portion and the third rigid portion are integrally formed, and the second end of the second covering portion and the first elastic portion are thermally fused together.

[0019] In conjunction with a first aspect of the embodiments of this application, in an optional embodiment, the first end of the first covering portion and the first rigid portion are integrally formed, the third end of the first covering portion and the third rigid portion are integrally formed, and the fourth end of the second covering portion and the second elastic portion are thermally fused together, and the second end of the second covering portion and the first elastic portion are thermally fused together.

[0020] In conjunction with a first aspect of the embodiments of this application, in an optional embodiment, the insulating film further includes flexible sheets, and flexible sheets are provided on both sides of the base plate along the thickness direction of the battery cell; of the two flexible sheets, one connects the base plate and the first covering portion, and the other connects the base plate and the second covering portion.

[0021] In conjunction with a first aspect of the embodiments of this application, in an optional embodiment, the battery cell further includes a top cover that covers the housing, and the insulating film further includes:

[0022] A top diaphragm is located between the battery cell and the top cover, and the top diaphragm is connected to the sidewall covering sheet. The top diaphragm has a hollow area for the tabs of the battery cell to pass through.

[0023] Secondly, embodiments of this application provide an electrical device, including any of the battery cells described above.

[0024] The battery cell and electrical device provided in this application include: a housing; a battery cell located inside the housing; an insulating film including a sidewall covering sheet and a first connecting assembly; the sidewall covering sheet is configured to cover the outer peripheral wall of the battery cell to separate the battery cell from the housing; the sidewall covering sheet includes a first end and a second end disposed opposite to each other along its circumference; the first connecting assembly includes a first connector and a second connector; the first connector includes a first rigid portion, and the second connector includes a second rigid portion and a first elastic portion; the first elastic portion connects the first end of the sidewall covering sheet and the second rigid portion, the first rigid portion connects the second end of the sidewall covering sheet, and the first rigid portion and the second rigid portion are engaged. As can be seen, the battery cell and electrical device of this application embodiment are connected by the first rigid part and the second rigid part, which is quick to connect and easy to disassemble. It does not require the use of hot melting process, which reduces the process cost and is also conducive to full utilization. Furthermore, through the first elastic part, while the side wall covering sheet binds the cell, the elastic action of the first elastic part effectively buffers the expansion force generated by the cell during charging and discharging, thereby effectively reducing the expansion range of the cell.

[0025] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0027] Figure 1A schematic diagram of the first type of insulating film in a battery cell provided in an embodiment of this application;

[0028] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle;

[0029] Figure 3 for Figure 1 A schematic diagram of the planar unfolded view of the insulating film in the diagram;

[0030] Figure 4 A schematic diagram of the second type of insulating film in a battery cell provided in an embodiment of this application;

[0031] Figure 5 for Figure 4 A magnified view of a portion of point B in the middle;

[0032] Figure 6 for Figure 4 A schematic diagram of the planar unfolded view of the insulating film.

[0033] Explanation of reference numerals in the attached figures:

[0034] 10. Base plate; 20. Side wall covering plate; 212. First covering part; 214. Second covering part; 221. First elastic part; 222. First rigid part; 231. Second rigid part; 241. Buckle; 242. Slot; 251. Third rigid part; 261. Fourth rigid part; 262. Second elastic part; 30. Top membrane; 40. Flexible sheet. Detailed Implementation

[0035] To make the technical solution and beneficial effects of this application more apparent and understandable, a detailed description is provided below by listing specific embodiments. The accompanying drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application pertains.

[0036] In the description of this application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used for the purpose of simplifying the description of this application and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. In other words, they should not be construed as limitations on this application.

[0037] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating the relative importance of the indicated features or the number of indicated technical features. Therefore, a feature specified as "first" or "second" may explicitly include at least one of those features. In the description of this application, "multiple" means at least two, such as two, three, etc.; "several" means at least one, such as one, two, three, etc., unless otherwise explicitly specified.

[0038] In this application, unless otherwise expressly defined, the terms "installation," "connection," "linking," "fixing," "setting," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can also refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0039] In this application, unless otherwise expressly defined, the terms "above," "on top of," "over," "above," "below," "below," "below," or "below" for "first feature over second feature" can refer to the first and second features being in direct contact, or to the first and second features being in indirect contact through an intermediate medium. Furthermore, "above," "over," and "below" for "first feature over second feature" can mean the first feature is directly above or diagonally above the second feature, or simply indicates that the horizontal height of the first feature is higher than the horizontal height of the second feature. Similarly, "below," "below," and "below" for "first feature over second feature" can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0040] To fully understand this application, detailed steps and structures will be presented in the following description to illustrate the technical solution of this application. Preferred embodiments of this application are described in detail below; however, in addition to these detailed descriptions, this application may have other implementation methods.

[0041] Example 1

[0042] To address the technical problems in related technologies, embodiments of this application provide a single battery cell. (See reference...) Figure 1 and Figure 2 The battery cell includes:

[0043] case;

[0044] The battery cell is located inside the casing;

[0045] An insulating film, including a sidewall covering sheet 20 and a first connecting assembly;

[0046] The sidewall covering sheet 20 covers the outer peripheral wall of the battery cell to separate the battery cell from the housing; the sidewall covering sheet 20 includes a first end and a second end disposed opposite to each other along its circumference;

[0047] The first connecting component includes a first connector 22 and a second connector 23; the first connector 22 includes a first rigid portion 222, and the second connector 23 includes a second rigid portion 231 and a first elastic portion 221; the first elastic portion 221 connects to the first end of the sidewall covering sheet 20 and the second rigid portion 231, the first rigid portion 222 connects to the second end of the sidewall covering sheet 20, and the first rigid portion 222 and the second rigid portion 231 are engaged.

[0048] Understandably, the shape of a battery cell includes square, cylindrical, and pouch cells, etc. This application mainly uses a square battery cell, i.e., a battery cell with a square casing, as an example for description. It is understood that the technical solution of this embodiment can also be used for battery cells of other shapes.

[0049] Understandably, the installation process of the insulating film can involve wrapping the folded insulating film around the battery cell and then folding it to fully cover the battery cell.

[0050] Understandably, the first rigid part 222 and the second rigid part 231, as well as the third rigid part 251 and the fourth rigid part 261 (hereinafter referred to as the third rigid part 251 and the fourth rigid part 261), are all made of rigid materials, while the first elastic part 221 and the second elastic part 262 (hereinafter referred to as the second elastic part 262) are all made of elastic materials. The difference between rigid materials and elastic materials is that rigid materials retain their dimensions or remain essentially unchanged when subjected to force, while elastic materials exhibit large dimensional deformation when subjected to force and can recover their shape after the force is removed. Specifically, the rigid material can be a plastic material such as PC (Polycarbonate) or PP (Polypropylene); the elastic material can be PET (Polyethylene terephthalate) or rubber.

[0051] Understandably, since the first rigid part 222, the second rigid part 231, and the third rigid part 251 and the fourth rigid part 261 (hereinafter referred to as the third and fourth rigid parts) are all relatively thin, they can all be bent and deformed. Thus, even if the first connector 22 and the second connector 23, as well as the third and fourth connectors (hereinafter referred to as the fourth connectors) are connected at the bent part of the battery cell, the first rigid part 222, the second rigid part 231, the third rigid part 251, and the fourth rigid part 261 can fit well into the bent part of the battery cell.

[0052] In this embodiment, the sidewall covering sheet 20 of the insulating film covers the periphery of the battery cell. A first elastic portion 221 connects the first end of the sidewall covering sheet 20 and the second rigid portion 231, and the second rigid portion 231 connects the second end of the sidewall covering sheet 20. The first rigid portion 222 and the second rigid portion 231 are engaged. Since the force-bearing dimension of the first elastic portion 221 can be increased, the distance between the first end and the second end of the sidewall covering sheet 20 can be increased. Thus, while the sidewall covering sheet 20 covers the outer periphery of the battery cell to bind the battery cell, the... At the same time, under the elastic action of the first elastic part 221, the expansion force generated by the cell during charging and discharging is effectively buffered, thereby effectively reducing the expansion range of the cell and effectively improving the situation of battery cell expansion deformation caused by the cell extruding and squeezing against the casing after expansion, thus effectively improving the safety of the battery cell in use; and since the first rigid part 222 and the second rigid part 231 are snapped together, disassembly and assembly are convenient, the connection is stable, no heat fusion process is required, reducing process cost, and the insulating film can be reused after disassembling unqualified battery cells.

[0053] It should be noted that the hardness and strength of the first hard portion 222, the second hard portion 231, and the third hard portion 251 and the fourth hard portion 261 can be increased by increasing their thickness. Specifically, the thickness of the first hard portion 222, the second hard portion 231, the third hard portion 251 and the fourth hard portion 261 can be between 0.1 mm and 1 mm, and the thickness value can be 0.3 mm, 0.5 mm or 0.8 mm. The deformation capacity of the first elastic portion 221 and the second elastic portion 262 can also be increased by decreasing their thickness. Specifically, the thickness of the first elastic portion 221 and the second elastic portion 262 can be between 6 μm and 300 μm, and the thickness value can be 10 μm, 20 μm, 30 μm, 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm, 200 μm, 250 μm or 280 μm.

[0054] See Figures 1 to 3 As shown, in this specific embodiment, the sidewall covering sheet 20 is made of a single sheet of insulating material, and the sidewall covering sheet 20 and the first elastic part are integrally formed.

[0055] Understandably, the sidewall covering sheet 20 and the second rigid part 231 are joined together by heat fusion, and the first elastic part 221 and the first rigid part 222 are also joined together by heat fusion, so that the connection is tight and convenient.

[0056] When the sidewall covering sheet 20 covers the battery cell, the sidewall covering sheet 20 is first wound around the periphery of the battery cell, and then the first rigid part 222 and the second rigid part 231 are snapped together. The structure is simple and the covering is convenient. Since the sidewall covering sheet 20 itself can also increase in size when subjected to force, it can further buffer the expansion force generated by the battery cell during charging and discharging, thereby effectively reducing the expansion range of the battery cell.

[0057] Continued Figures 1 to 3 In order to allow the second rigid part 231 to engage with the second rigid part 231, one of the first rigid part 222 and the second rigid part 231 has a buckle 241 and the other has a slot 242 that engages with the buckle 241.

[0058] That is, the first rigid part 222 is provided with a buckle 241 and the second rigid part 231 is provided with a slot 242; or the first rigid part 222 is provided with a slot and the second rigid part 231 is provided with a buckle.

[0059] It is understandable that the latch 241 and the first rigid part 222 are integrally formed, that is, the latch 241 is formed by extending from the first rigid part 222.

[0060] The first rigid part 222 and the second rigid part 231 are connected by the snap-fit ​​of the snap-fit ​​241 and the snap-fit ​​of the slot 242, which makes it easy to assemble and disassemble.

[0061] Specifically, see Figure 2 and Figure 3 As shown, a slot 242 is disposed in the second rigid part 231, and a latch 241 is disposed in the first rigid part 222. The slot 242 can be a slit or an opening in the second rigid part 231. The latch 241 includes a neck connected to the first rigid part 222 and a head connected to the neck. The dimension of the head along the height of the battery cell is greater than the dimension of the slot 242 along the height of the battery cell, and the dimension of the neck along the height of the battery cell is less than or equal to the dimension of the slot 242 along the height of the battery cell. When the slot 242 and the latch 241 are connected, the head of the latch 241 is first bent and deformed to pass through the slot 242, and then the head of the latch 241 is restored to its original shape so that the head of the latch 241 and the slot 242 are engaged.

[0062] It should be noted that there are various structures for the buckle 241 and the slot 242, as long as the buckle 241 and the slot 242 can achieve a snap-fit ​​connection.

[0063] Continued Figures 1 to 3 The insulating film also includes a bottom support sheet 10, which covers the bottom of the battery cell; the bottom support sheet 10 is in contact with the side wall covering sheet 20.

[0064] It is understandable that the material used to make the base plate 10 is the same as that used to make the first rigid part 222, meaning that the size of the base plate 10 remains unchanged or essentially unchanged when subjected to force.

[0065] Understandably, when the insulating film is in the unfolded state, see [reference needed]. Figure 3 As shown, the base plate 10 and the first rigid portion 222 are integrally formed, that is, the base plate 10 is formed by extending the first rigid portion 222; when the insulating film is in the wrapped state, see Figure 1 As shown, the bottom support plate 10 is connected to both ends of its width by tape and side wall covering plate 20.

[0066] By setting a base plate 10 to support the battery cell, the battery cell can be lifted up, thus avoiding interference between the bottom edge of the battery cell and the inner R-angle of the bottom of the casing.

[0067] This application also provides an electrical device, including the battery cell described above.

[0068] Example 2

[0069] The basic structure of a single battery cell in this embodiment is the same as in Embodiment 1, except that: (Refer to...) Figures 4-6 The sidewall covering sheet 20 includes a first covering portion 212, a second covering portion 214, and a second connecting assembly. The first covering portion 212 and the second covering portion 214 are located on both sides of the thickness direction of the battery cell. The first covering portion 212 has a first end and a third end that are arranged opposite to each other along the length direction of the battery cell. The second covering portion 214 has a second end and a fourth end that are arranged opposite to each other along the length direction of the battery cell. The third end of the first covering portion 212 and the fourth end of the second covering portion 214 are connected by the second connecting assembly. The second connecting assembly includes a third connector and a fourth connector. The third connector includes a third rigid portion 251, and the fourth connector includes a fourth rigid portion 261 and a second elastic portion 262. One end of the third end and the fourth end are connected to the third rigid portion 251, and the other end is connected to the fourth rigid portion 261 through the second elastic portion 262. The fourth rigid portion 261 and the third rigid portion 251 are engaged.

[0070] Understandably, the materials used to make the first covering part 212 and the second covering part 214 are the same as those used to make the first hard part, and their dimensions remain unchanged or substantially unchanged when subjected to force.

[0071] In this embodiment, when the sidewall covering sheet 20 covers the battery cell, the first covering part 212 and the second covering part 214 are first placed on both sides of the thickness direction of the battery cell, and then the fourth rigid part 261 and the third rigid part 251 are snapped together, and the first rigid part 222 and the second rigid part 231 are snapped together. The structure is simple and the covering is convenient. Moreover, due to the presence of the second elastic part 262, the distance between the third end of the first covering part 212 and the fourth end of the second covering part 214 becomes larger, which can further buffer the expansion force generated by the battery cell during charging and discharging, thereby effectively reducing the expansion range of the battery cell.

[0072] It should be noted that, in order to allow the fourth rigid part 261 and the third rigid part 251 to engage, it is possible to design that one of the fourth rigid part 261 and the third rigid part 251 has a buckle 241 and the other has a slot 242 that engages with the buckle 241.

[0073] See Figure 6 As shown, in some embodiments, the first end of the first covering portion 212 and the first hard portion 222 are integrally formed, the third end of the first covering portion 212 and the third hard portion 251 are integrally formed, and the fourth end of the second covering portion 214 and the second elastic portion 262 are thermally fused together, and the second end of the second covering portion 214 and the first elastic portion 221 are thermally fused together.

[0074] In some other embodiments, the first end of the first covering portion 212 and the first rigid portion 222 are integrally formed, the third end of the first covering portion 212 and the second elastic portion 262 are thermally fused together, and the fourth end of the second covering portion 214 and the third rigid portion 251 are integrally formed, and the second end of the second covering portion 214 and the first elastic portion 221 are thermally fused together.

[0075] Accordingly, in this embodiment, the second elastic part 262 and the fourth hard part 261 can also be heat-fused together; the first elastic part 221 and the second hard part 231 can also be heat-fused together.

[0076] Continued Figure 6 As shown, in some embodiments, the insulating film further includes a flexible sheet 40, and the base plate 10 is provided with flexible sheets 40 on both sides along the thickness direction of the battery cell; of the two flexible sheets 40, one connects the base plate 10 and the first covering part 212, and the other connects the base plate 10 and the second covering part 214.

[0077] Understandably, the flexible sheet 40 is made of the same material as the first elastic part, meaning that its size can increase when subjected to force and can recover when the force is removed.

[0078] The presence of the flexible sheet 40 allows the same insulating film to cover multiple battery cells of different thicknesses, resulting in better applicability.

[0079] It should be noted that one flexible sheet 40 is connected to the base plate 10 and the first covering part 212 by heat fusion, and another flexible sheet 40 is connected to the base plate 10 and the second covering part 214 by heat fusion.

[0080] Continued Figure 4 and Figure 6 In some embodiments, the insulating film further includes a top film 30, and the battery cell further includes a top cover that covers the housing. The top film 30 is located between the cell and the top cover, and the top film 30 is connected to the side wall covering 20. The top film 30 has a hollow area through which the tabs of the cell pass. The top film 30 is provided to prevent the cell from moving around in the housing.

[0081] It should be noted that the top membrane 30 can be a single membrane with the cutout area set on the single membrane; or the top membrane 30 can be composed of multiple segments with the cutout area formed between two adjacent segments.

[0082] It should also be noted that the material used to make the top diaphragm 30 is the same as that used to make the first rigid part, meaning that its dimensions remain unchanged or essentially unchanged when subjected to force.

[0083] Specifically, in this embodiment, the top membrane 30 includes two sections, with a hollow area formed between the two adjacent sections; one of the two sections is integrally formed with the first rigid part 222, and the other is integrally formed with the third rigid part 251.

[0084] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations of the technical solutions contained in this application. Various modifications and changes can be made to the above embodiments without departing from the scope of this application. Similarly, the various technical features of the above embodiments can be arbitrarily combined to form other embodiments of this application that may not be explicitly described. Therefore, the above embodiments merely illustrate several implementations of this application and do not limit the scope of protection of this patent application.

Claims

1. A battery cell, characterized in that, include: case; The battery cell is located inside the housing; An insulating film, including a sidewall covering sheet (20) and a first connecting assembly; The sidewall covering sheet (20) covers the outer peripheral wall of the battery cell to separate the battery cell from the housing; the sidewall covering sheet (20) includes a first end and a second end disposed opposite to each other along its circumference; The first connecting component includes a first connector and a second connector; the first connector includes a first rigid part (222), and the second connector includes a second rigid part (231) and a first elastic part (221); the first elastic part (221) connects the first end of the sidewall covering sheet (20) and the second rigid part (231), the first rigid part (222) connects the second end of the sidewall covering sheet (20), and the first rigid part (222) and the second rigid part (231) are engaged.

2. The battery cell according to claim 1, characterized in that, In the first rigid part (222) and the second rigid part (231), one has a snap fastener (241) and the other has a slot (242) that engages with the snap fastener (241).

3. The battery cell according to claim 1, characterized in that, The insulating film further includes: A bottom support plate (10) covers the bottom of the battery cell; the bottom support plate (10) is in contact with the side wall covering plate (20).

4. The battery cell according to any one of claims 1 to 3, characterized in that, The sidewall covering sheet (20) is made of a single sheet of insulating material, and the sidewall covering sheet (20) and the first elastic part (221) are integrally formed.

5. The battery cell according to claim 3, characterized in that, The sidewall covering sheet (20) includes a first covering portion (212), a second covering portion (214), and a second connecting assembly. The first covering portion (212) and the second covering portion (214) are located on opposite sides of the thickness direction of the battery cell. The first covering portion (212) has a first end and a third end that are disposed opposite to each other along the length direction of the battery cell. The second covering portion (214) has a second end and a fourth end that are disposed opposite to each other along the length direction of the battery cell. The third end of the first covering portion (212) and the second covering portion (214) are connected together. A second connecting component is provided between the fourth end of 14); the second connecting component includes a third connecting member and a fourth connecting member, the third connecting member includes a third rigid part (251), the fourth connecting member includes a fourth rigid part (261) and a second elastic part (262), one end of the third end and the fourth end are connected to the third rigid part (251), and the other end is connected to the fourth rigid part (261) through the second elastic part (262); the fourth rigid part (261) and the third rigid part (251) are engaged.

6. The battery cell according to claim 5, characterized in that, The first end of the first covering part (212) is integrally formed with the first hard part (222), the third end of the first covering part (212) is thermally fused with the second elastic part (262), and the fourth end of the second covering part (214) is integrally formed with the third hard part (251), and the second end of the second covering part (214) is thermally fused with the first elastic part (221).

7. The battery cell according to claim 5, characterized in that, The first end of the first covering part (212) is integrally formed with the first hard part (222), the third end of the first covering part (212) is integrally formed with the third hard part (251), and the fourth end of the second covering part (214) is thermally fused to the second elastic part (262), and the second end of the second covering part (214) is thermally fused to the first elastic part (221).

8. The battery cell according to claim 5, characterized in that, The insulating film also includes flexible sheets (40), and the base plate (10) is provided with flexible sheets (40) on both sides along the thickness direction of the battery cell; of the two flexible sheets (40), one connects the base plate (10) and the first covering part (212), and the other connects the base plate (10) and the second covering part (214).

9. The battery cell according to claim 1, characterized in that, The battery cell also includes a top cover that covers the housing, and the insulating film also includes: A top diaphragm (30) is located between the battery cell and the top cover, and the top diaphragm (30) is connected to the sidewall covering sheet (20). The top diaphragm (30) has a hollow area for the tabs of the battery cell to pass through.

10. An electrical appliance, characterized in that, Includes the battery cell described in any one of claims 1-9.

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