Battery cell

Abstract

The application discloses a battery monomer, and relates to the technical field of batteries. The battery monomer comprises a shell, an electrode assembly, an insulating film and a cover plate assembly. The shell has an opening; the electrode assembly is arranged in the shell; the insulating film is arranged in the shell and wraps the electrode assembly; the cover plate assembly is connected with the shell and used for closing the opening; and the cover plate assembly comprises a cover plate and a lower plastic, and the lower plastic is arranged between the electrode assembly and the cover plate in a second direction. Part of the structure of the insulating film forms a first clamping part arranged in a first direction, the lower plastic is provided with a second clamping part arranged in the first direction, and the first clamping part and the second clamping part are clamped and matched with each other to fix the electrode assembly and the insulating film. Therefore, the risk of internal short circuit of the electrode assembly when the insulating film is hot melted can be reduced, the space utilization rate of the battery monomer in the connecting direction of the electrode assembly and the cover plate assembly can be increased, and the energy density of the battery monomer is improved.

Description

Technical Field

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

[0002] A single battery cell includes a casing, an electrode assembly housed inside the casing, and a cover assembly located at the opening of the casing. Before the electrode assembly is installed into the casing, an insulating film must be wrapped around it to prevent scratches from the casing during installation and to prevent short circuits caused by the connection between the electrode assembly and the casing. The insulating film is attached to the plastic under the cover using thermoforming welding. However, during the thermoforming process, molten beads can easily fall into the electrode assembly, causing damage to the separator. This can lead to a short circuit between the positive and negative electrodes, increasing the safety risk of the battery cell. Summary of the Invention

[0003] The purpose of this invention is to provide a battery cell to solve the technical problem that the electrode assembly is prone to internal short circuits when the insulating film and the lower plastic are hot-melted.

[0004] To achieve the above objectives, the present invention provides a battery cell, comprising: a housing having an opening; an electrode assembly disposed within the housing; an insulating film disposed within the housing and enclosing the electrode assembly; and a cover assembly, the cover assembly comprising a cover plate and a lower plastic, the cover plate being connected to the housing and closing the opening, and the lower plastic being disposed between the electrode assembly and the cover plate in a second direction; wherein, a portion of the insulating film forms a first snap-fit ​​portion disposed in a first direction, and the lower plastic having a second snap-fit ​​portion disposed in the first direction, the first snap-fit ​​portion and the second snap-fit ​​portion engaging with each other to fix the electrode assembly and the insulating film.

[0005] In some embodiments, the electrode assembly includes a first surface, a second surface, and a connecting surface connected between the first surface and the second surface; the insulating film includes a first wrapping portion, a second wrapping portion, and a connecting portion connected between the first wrapping portion and the second wrapping portion; the first wrapping portion wraps around the first surface, the second wrapping portion wraps around the second surface, the connecting portion wraps around the connecting surface, and the side of the first wrapping portion and the second wrapping portion away from the connecting portion is provided with at least one first snap-fit ​​portion.

[0006] In some embodiments, the first engaging portion is a lug extending along a first direction, and the second engaging portion is a through hole extending along the first direction; or, the first engaging portion is a through hole extending along the first direction, and the second engaging portion is a lug extending along the first direction; wherein the lug and the through hole engage with each other.

[0007] In some embodiments, the lug includes a first part extending along a first direction, and the lug has corresponding fixing parts on both sides in a second direction, wherein the first part is disposed in a through hole, and the fixing parts abut against the wall surface of the lower plastic.

[0008] In some embodiments, the lug further includes a second portion extending in a second direction, and the second portion is connected between the first wrapping portion and the first portion and between the second wrapping portion and the first portion.

[0009] In some embodiments, the dimension of the first part in the third direction is smaller than the dimension of each fixing part in the third direction; the ratio of the dimension of the through hole in the third direction to the dimension of each fixing part in the third direction is 0.55-1.

[0010] In some embodiments, the ratio of the dimension of each fixing part in the third direction to the dimension of the second part in the second direction is 2-9; the ratio of the dimension of each fixing part in the third direction to the dimension of the second part in the third direction is 1-1.5.

[0011] In some embodiments, the lower plastic includes a main body and a first side portion, the main body having a first side portion on each side in a first direction, and the first side portion having at least one second snap-fit ​​portion.

[0012] In some embodiments, the material used for the first snap-fit ​​portion includes at least one of polypropylene, polyethylene, polyimide, and polyethylene terephthalate.

[0013] In some embodiments, the battery cell further includes: an electrode assembly including an electrode body portion and a tab portion, the tab portion being connected to the body portion along a second direction; and a cover plate assembly further including a terminal post, the terminal post being disposed on the cover plate and connected to the tab portion.

[0014] The technical advantage of this invention lies in providing a battery cell where a portion of the insulating film forms a first snap-fit ​​portion arranged along a first direction, and the lower plastic portion has a second snap-fit ​​portion arranged along the first direction. The first and second snap-fit ​​portions engage with each other to fix the electrode assembly and the cover assembly. Therefore, it can both prevent internal short circuits in the electrode assembly during heat fusion of the insulating film and increase the space utilization rate of the battery cell in the connection direction between the electrode assembly and the cover assembly, thereby improving the energy density of the battery cell. Attached Figure Description

[0015] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0016] Figure 1 This is a schematic diagram of the structure of a battery cell provided in the embodiments of this application, mainly showing the structure of the electrode assembly not being wrapped by the insulating film.

[0017] Figure 2 This is a schematic diagram of the structure of a battery cell provided in the embodiments of this application, mainly showing the structural schematic diagram of the electrode assembly to be wrapped.

[0018] Figure 3 This is a schematic diagram of the structure of the electrode assembly provided in an embodiment of this application.

[0019] Figure 4 This is a schematic diagram of the structure of the insulating film provided in an embodiment of this application.

[0020] Figure 5 for Figure 4 Enlarged view of point A in the middle.

[0021] Figure 6 This is a schematic diagram of the interlocking structure of the first and second snap-fit ​​parts provided in the embodiments of this application. Figure 1 .

[0022] Figure 7 for Figure 6 Enlarged view of point B in the middle.

[0023] Figure 8 This is a schematic diagram of the interlocking structure of the first and second snap-fit ​​parts provided in the embodiments of this application. Figure 2 .

[0024] Figure 9 for Figure 8 Enlarged view of point C in the middle.

[0025] The components in the attached diagram are labeled as follows:

[0026] 1-Shell; 10-Opening; 11-Cavity;

[0027] 2-Electrode assembly; 201-Body part; 202-Electrode tab part; 21-First surface; 22-Second surface; 23-Connecting surface;

[0028] 3-Insulating film; 31-First wrapping part; 32-Second wrapping part; 33-Connecting part; 301-First snap-fit ​​part; 311-First part; 312-Fixing part; 313-Second part; 321-First crease; 322-Second crease;

[0029] 4-Cover assembly; 41-Cover body; 42-Lower plastic; 421-Main body; 422-First side; 401-Second snap-fit ​​part; 43-Position post; 44-Upper plastic;

[0030] X - First direction; Z - Second direction; Y - Third direction. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] In the accompanying drawings, shapes and dimensions may be enlarged for clarity, and the same reference numerals will be used in all figures to indicate the same or similar parts.

[0033] In the description of this application, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In particular, "height" corresponds to the dimension from top to bottom, "width" corresponds to the dimension from left to right, and "depth" corresponds to the dimension from front to back; these are relative concepts and may therefore vary according to different positions and usage states. Therefore, these or other orientations should not be interpreted as restrictive terms.

[0034] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0035] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0036] In the embodiments of this application, the terms "multiple" and "various types" refer to two or more kinds. In the embodiments of this application, unless otherwise specified, the description "parallel" indicates approximate parallelism within a certain allowable error range, which can be a range where the angle of deviation from absolute parallelism is less than or equal to 5°. The description "perpendicular" indicates approximate perpendicularity within a certain allowable error range, which can be a range where the angle of deviation from absolute perpendicularity is less than or equal to 5°.

[0037] To address the technical problem of short circuits caused by separator damage during thermal melting of the insulating film, which leads to short circuits between the positive and negative electrodes, this application provides a battery cell including a housing, an electrode assembly, an insulating film, and a cover assembly. The housing has an opening; the electrode assembly is disposed within the housing; the insulating film is disposed within the housing and encloses the electrode assembly; the cover assembly is connected to the housing and seals the opening. The cover assembly includes a cover plate and a lower plastic layer, which is disposed between the electrode assembly and the cover plate in a second direction. A portion of the insulating film forms a first snap-fit ​​portion along a first direction, and the lower plastic layer has a second snap-fit ​​portion along the first direction. The first and second snap-fit ​​portions engage with each other to secure the electrode assembly and the cover assembly. Therefore, this design avoids internal short circuits in the electrode assembly during thermal melting of the insulating film and increases the space utilization of the battery cell in the connection direction between the electrode assembly and the cover assembly.

[0038] like Figure 1 As shown, each battery cell has two perpendicular directions: a first direction X, a second direction Z, and a third direction Y. When the battery cell is placed vertically, that is... Figure 1 In the structure, the first direction X is the thickness direction of the battery cell, the second direction Z is the height direction of the battery cell, and the third direction Y is the width direction of the battery cell. When the battery cell is placed on its side (not shown in the figure), the first direction X is the length direction of the battery cell (i.e.,...). Figure 1 The first direction (Z) is the height direction of the battery cell, the second direction (Z) is the width direction of the battery cell, and the third direction (Y) is the thickness direction of the battery cell. It should be noted that the vertical or side-standing position of the battery cell is equivalent to the cover plate. When the cover plate is located on the top of the housing 1, the battery cell is vertically placed. When the cover plate is located on the side of the housing 1, the battery cell is side-standing.

[0039] like Figure 1 As shown, the housing 1 has an opening 10 communicating with the cavity 11. The housing 1 is made of aluminum to ensure good heat dissipation of the battery. The housing 1 can also be made of copper, iron, aluminum alloy, or other materials.

[0040] like Figure 1As shown, the electrode assembly 2 is disposed within the housing 1, that is, the electrode assembly 2 is disposed within the cavity 11. The electrode assembly 2 includes an electrode body portion 201 and an electrode tab portion 202. The electrode tab portion 202 is connected to the body portion 201 along the second direction Z, and the electrode tab portion 202 includes a positive electrode tab and a negative electrode tab.

[0041] Specifically, the electrode assembly 2 includes a positive electrode plate, a negative electrode plate, and a separator. The positive and negative electrode plates are stacked, and the separator is disposed between the positive and negative electrode plates to achieve an insulating effect between them. It can be understood that the electrode assembly 2 is stacked in the order of positive electrode plate, separator, negative electrode plate, separator, etc., to form the body portion 201. The tabs leading from the positive electrode plate are positive tabs, and the tabs leading from the negative electrode plate are negative tabs. Multiple positive tabs are stacked to form a positive tab portion, and multiple negative tabs are stacked to form a negative tab portion. For example... Figure 1 As shown, two electrode assemblies 2 are stacked along the first direction X to form the core of a battery cell. Each electrode assembly 2 has two tabs extending from the same side.

[0042] like Figure 2 As shown, the cover plate assembly 4 includes a cover plate, a lower plastic 42, and an electrode post 43.

[0043] like Figure 1 and Figure 2 As shown, the cover plate is connected to the housing 1 and closes the opening 10. The cover plate is rectangular, and its shape and size are adapted to the shape of the opening 10 in the housing 1 to close the opening 10 and protect the electrode assembly 2 installed inside the housing 1. The cover plate can be made of a material with a certain degree of hardness to prevent deformation of the cover plate when subjected to external force impact, and to prevent the external force from being transmitted to the electrode assembly 2 through the cover plate, causing damage to the electrode assembly 2.

[0044] like Figure 2 As shown, the cover plate has electrode holes for accommodating the electrode post 43. Two tabs 202 with the same polarity can be connected to the electrode post 43 via connecting tabs (not shown). For example, the positive tab is connected to the positive electrode post 43 via a positive connecting tab, and the negative tab is connected to the negative electrode post 43 via a negative connecting tab.

[0045] like Figure 1 and Figure 2 As shown, the lower plastic 42 is disposed between the electrode assembly 2 and the cover plate in the second direction Z, which can achieve insulation between the cover plate and the electrode assembly 2 and avoid short circuit.

[0046] like Figure 2As shown, in one embodiment, the lower plastic 42 includes a main body 421 and a first side 422. The main body 421 is provided with a first side 422 on each side of the first direction X. The first side 422 is provided with at least one second snap-fit ​​portion 401. The main body 421 is provided with a second side 423 on each side of the third direction Y. The second side 423 is connected between the two first side portions 422.

[0047] like Figure 2 As shown, the insulating film 3 is disposed inside the housing 1 and wraps around the electrode assembly 2. The insulating film 3 can be a polypropylene film, a polyethylene film, etc.

[0048] like Figure 2 As shown, in one embodiment, a portion of the insulating film 3 forms a first snap-fit ​​portion 301 disposed along the first direction X, and the lower plastic 42 is provided with a second snap-fit ​​portion 401 disposed along the first direction X. The first snap-fit ​​portion 301 and the second snap-fit ​​portion 401 are snapped together to fix the electrode assembly 2 and the cover plate assembly 4.

[0049] It should be noted that the conventional lower plastic assembly includes a main body with protrusions on its lower surface, which are then heat-welded to the insulating film. During the heat-welding process, molten beads can easily fall into the electrode assembly, damaging the separator and causing a short circuit between the positive and negative electrodes, increasing the safety risk of the battery cell. During the assembly of the cover assembly and the casing, the protrusions in the lower plastic assembly can easily damage the negative electrode of the electrode assembly when it is inserted into the casing, causing material to detach from the negative electrode and resulting in abnormal self-discharge of the battery cell, reducing the overall yield of the production line.

[0050] Therefore, compared to the conventional lower plastic 42, the lower plastic 42 in this embodiment of the application eliminates the protrusion setting and provides a second snap-fit ​​part 401 on the body part 201. The first snap-fit ​​part 301 of the insulating film 3 cooperates with the second snap-fit ​​part 401 of the lower plastic 42 to better fix the lower plastic 42 and the insulating film 3, avoid the problem of molten beads falling into the electrode assembly 2 and causing internal short circuit, and ensure the yield of the assembly process and improve the yield of the entire production line.

[0051] like Figure 3 As shown, in one embodiment, the electrode assembly 2 includes a first surface 21, a second surface 22 disposed opposite to each other, and a connecting surface 23 connecting the first surface 21 and the second surface 22. The first surface 21 and the second surface 22 are both surfaces of the electrode assembly 2 with the largest area, and the connecting surface 23 is the surface of the electrode assembly 2 with the smallest area.

[0052] like Figure 4 As shown, the insulating film 3 includes a first wrapping portion 31, a second wrapping portion 32 disposed opposite to each other, and a connecting portion 33 connecting the first wrapping portion 31 and the second wrapping portion 32.

[0053] The first wrapping part 31, the second wrapping part 32, and the connecting part 33 are connected in one piece, which facilitates the production and processing of the insulating film 3.

[0054] like Figure 4 As shown, a first crease 321 is provided between the first wrapping portion 31 and the connecting portion 33, and a second crease 322 is provided between the second wrapping portion 32 and the connecting portion 33. When the insulating film 3 covers the electrode assembly 2, the first wrapping portion 31 and the connecting portion 33 are bent along the path of the first crease 321, and the second wrapping portion 32 and the connecting portion 33 are bent along the path of the second crease 322, so that the first wrapping portion 31 is wrapped around the first surface 21, the second wrapping portion 32 is wrapped around the second surface 22, and the connecting portion 33 is wrapped around the connecting surface 23.

[0055] like Figures 2 to 4 As shown, at least one first snap-fit ​​portion 301 is provided on the side of the first wrapping portion 31 and the second wrapping portion 32 away from the connecting portion 33. It can be understood that when the insulating film 3 is not bent, multiple first snap-fit ​​portions 301 are provided on two sides of the insulating film 3 in the second direction Z. After the insulating film 3 is bent, the two sides of the insulating film 3 with multiple first snap-fit ​​portions 301 are respectively provided on both sides of the cover plate in the first direction X.

[0056] The first connection method between the first latching part 301 and the second latching part 401 is as follows: the first latching part 301 is a lug extending along the first direction X, and the second latching part 401 is a through hole extending along the first direction X. It can be understood that the first latching part 301 on the insulating film 3 is a lug, and the second latching part 401 on the lower plastic 42 is a through hole.

[0057] The first connection method described above is designed to make the lug and the through hole engage with each other to better fix the lower plastic 42 and the insulating film 3, avoid the problem of molten beads falling into the electrode assembly 2 and causing internal short circuits, and ensure the yield of the assembly process and improve the yield of the entire production line.

[0058] During installation, the lug is inserted into the through hole and folded and deformed in the second direction Z, so that the lug covers the inner surface of the lower plastic 42. In this way, the space occupied by the lug in the second direction Z can be reduced, thereby improving the space utilization rate of the battery cell in the second direction Z and increasing the energy density of the battery cell. At the same time, the two sides of the lug passing through the through hole in the first direction X can be respectively engaged with the edge of the through hole, thereby improving the stability of the assembly of the lug and the through hole and preventing the lug of the insulating film 3 from falling out of the through hole when subjected to external force.

[0059] The second connection method between the first latching part 301 and the second latching part 401 is as follows: the first latching part 301 is a through hole extending along the first direction X, and the second latching part 401 is a lug extending along the first direction X. It can be understood that the first latching part 301 on the insulating film 3 is a through hole, and the second latching part 401 on the lower plastic 42 is a lug.

[0060] The second connection method mentioned above is also designed to make the lug and the through hole engage with each other to better fix the lower plastic 42 and the insulating film 3, avoid the problem of molten beads falling into the electrode assembly 2 and causing internal short circuits, and ensure the yield of the assembly process and improve the yield of the entire production line.

[0061] During installation, the lug of the lower plastic 42 is inserted into the through hole of the insulating film 3 and folded and deformed in the second direction Z, so that the lug of the lower plastic 42 is attached to the outer surface of the insulating film 3. In this way, the space occupied by the lug in the second direction Z can be reduced, thereby improving the space utilization rate of the battery cell in the second direction Z. At the same time, the two sides of the lug passing through the through hole in the first direction X can be engaged with the edge of the through hole respectively, thereby improving the stability of the assembly of the lug and the through hole and preventing the lug of the lower plastic 42 from falling out of the through hole when subjected to external force.

[0062] It should be noted that although no structural diagram is given for the second connection method between the first latching part 301 and the second latching part 401, it is based on... Figure 1 And considering the relationship between the two locking parts, it's easy to imagine the relationship between the lug and the through hole after they are swapped.

[0063] like Figures 5 to 9 As shown, in one embodiment, the lug includes a first portion 311 extending along a first direction X, and corresponding fixing portions 312 are provided on both sides of the lug in a second direction Z. The first portion 311 is disposed in a through hole, and the fixing portions 312 abut against the wall surface of the lower plastic 42. The lug is inserted into the through hole, and the first portion 311 and each lug are bent along the path of the connecting line, so that each fixing portion 312 is attached to the inner wall surface of the lower plastic 42.

[0064] like Figures 5 to 9As shown, in one embodiment, the lug further includes a second portion 313 extending along the second direction Z, and the second portion 313 connects the first wrapping portion 31 and the first portion 311, as well as the second wrapping portion 32 and the first portion 311. It is understood that on one side of the cover plate along the third direction Y, the second portion 313 connects the first wrapping portion 31 and the first portion 311; on the other side of the cover plate along the third direction Y, the second portion 313 connects the second wrapping portion 32 and the first portion 311. This allows for greater operating space when the lug is inserted into the through hole, while preventing damage to the first wrapping portion 31 or the second wrapping portion 32 when the lug is bent.

[0065] The aforementioned lug can be formed by stacking two protrusions together, that is, each protrusion includes a connected first part 311, a second part 313, and a fixing part 312. Of course, the aforementioned lug can also be a one-piece molded structure.

[0066] The size of the first part 311 in the third direction Y is smaller than the size of each fixing part 312 in the third direction Y. This allows the first part 311 to be located inside the through hole after the lug passes through the through hole, and the two fixing parts 312 to be engaged with the edge of the through hole respectively, thereby improving the stability of the lug and the through hole assembly and preventing the lug from falling out of the through hole when subjected to external force.

[0067] The ratio of the size of the through hole in the third direction Y to the size of each fixing part 312 in the third direction Y is 0.55-1. Within this range, while ensuring the assembly stability of the two snap-fit ​​parts, it also avoids the through hole diameter being too large, which would affect the structural strength of the lower plastic 42. If the size of the through hole in the third direction Y is too large, the size of the lower plastic 42 will also be too large, which will reduce the effective active area of ​​the electrode assembly 2 and reduce the energy density of the battery cell. The specific ratio of the size of the through hole in the third direction Y to the size of each fixing part 312 in the third direction Y can be any one of 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 1, or any value between any two of these values.

[0068] The ratio of the dimension of each fixing part (313) in the third direction (Y) to the dimension of the second part (312) in the second direction (Z) is 2-9. This avoids the fixing part 312 or the second part 313 having a large dimension in the second direction (Z), thus reducing the space utilization rate of the insulating film 3 in the battery cell in the second direction (Z). The specific ratio of the dimension of each fixing part (313) in the third direction (Y) to the dimension of the second part (312) in the second direction (Z) can be any one of 2, 3, 4, 5, 6, 7, 8, 9 or any value between any two values.

[0069] The ratio of the dimension of each fixing part (313) in the third direction (Y) to the dimension of the second part (312) in the third direction (Y) is 1-1.5. This allows for better interconnection between the first snap-fit ​​part 301 and the second snap-fit ​​part 401, improving assembly strength and reducing the risk of short circuits between the electrode assembly and the housing. The specific ratio of the dimension of each fixing part 313 in the third direction (Y) to the dimension of the second part 312 in the third direction (Y) can be any one of 1, 1.1, 1.2, 1.3, 1.4, or 1.5, or any value between any two of these ratios.

[0070] The dimension of the first part 311 in the third direction Y is 3-16mm. It can be understood that the dimension (unit: mm) of the first part 311 in the third direction Y can be any one of 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 or any value between any two of them.

[0071] Each fixing part 312 has a dimension of 3-5 mm in the second direction Z. It is understood that the dimension (in mm) of each fixing part 312 in the second direction Z can be any one of 3, 4, or 5, or any value between any two values. Each fixing part 312 has a dimension of 7-20 mm in the third direction Y. The dimension (in mm) of each fixing part 312 in the third direction Y can be any one of 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20, or any value between any two values.

[0072] The dimension of the second part 313 in the third direction Y is 10-25 mm. It can be understood that the dimension (in mm) of the second part 313 in the third direction Y can be any one of 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or any value between any two of these. The dimension of the second part 313 in the second direction Z is 3-5 mm. It can be understood that the dimension (in mm) of the second part 313 in the second direction Z can be any one of 3, 4, 5, or any value between any two of these.

[0073] The insulating film 3 is made of at least one of polypropylene, polyethylene, polyimide, and polyethylene terephthalate. Since the first snap-fit ​​portion 301 is part of the insulating film 3, the first snap-fit ​​portion 301 is also made of at least one of polypropylene, polyethylene, polyimide, and polyethylene terephthalate.

[0074] This application also provides an electrical device, including the aforementioned battery cell. The electrical device can be an automobile, mobile phone, portable device, laptop, ship, spacecraft, electric toy, and power tool, etc. Automobiles can be gasoline-powered vehicles, natural gas-powered vehicles, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; 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, etc. This application does not impose any special limitations on the aforementioned electrical device.

[0075] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0076] The above provides a detailed description of a battery cell provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell, characterized in that, include: A housing having an opening; Electrode assembly, disposed within the housing; An insulating film is disposed inside the housing and encloses the electrode assembly; as well as A cover plate assembly, the cover plate assembly including a cover plate and a lower plastic, the cover plate being connected to the housing and closing the opening, and the lower plastic being disposed in a second direction between the electrode assembly and the cover plate; The insulating film near the cover plate has a first snap-fit ​​portion arranged in a first direction, and the lower plastic has a second snap-fit ​​portion arranged in the first direction. The first snap-fit ​​portion and the second snap-fit ​​portion engage with each other to fix the electrode assembly and the insulating film.

2. The battery cell according to claim 1, characterized in that, The electrode assembly includes a first surface, a second surface, and a connecting surface connecting the first surface and the second surface, which are disposed opposite to each other. The insulating film includes a first wrapping portion, a second wrapping portion, and a connecting portion connecting the first wrapping portion and the second wrapping portion, which are disposed opposite to each other. The first wrapping portion wraps around the first surface, the second wrapping portion wraps around the second surface, the connecting portion wraps around the connecting surface, and the side of the first wrapping portion and the second wrapping portion away from the connecting portion is provided on at least one of the first snap-fit ​​portions.

3. The battery cell according to claim 2, characterized in that, The first engaging portion is a lug extending along the first direction, and the second engaging portion is a through hole extending along the first direction; or... The first latching part is a through hole extending along the first direction, and the second latching part is a lug extending along the first direction; The lug and the through hole are engaged with each other.

4. The battery cell according to claim 3, characterized in that, The lug includes a first part extending along the first direction, and the lug has corresponding fixing parts on both sides in the second direction. The first part is disposed in the through hole, and the fixing parts abut against the wall of the lower plastic.

5. The battery cell according to claim 4, characterized in that, The lug also includes a second portion extending along the second direction, and the second portion is connected between the first wrapping portion and the first portion, and between the second wrapping portion and the first portion.

6. The battery cell according to claim 4, characterized in that, The dimension of the first part in the third direction is smaller than the dimension of each of the fixing parts in the third direction; The ratio of the dimension of the through hole in the third direction to the dimension of each of the fixing parts in the third direction is 0.55-1.

7. The battery cell according to claim 5, characterized in that, The ratio of the dimension of each fixing part in the third direction to the dimension of the second part in the second direction is 2-9; The ratio of the dimension of each of the fixing parts in the third direction to the dimension of the second part in the third direction is 1-1.

5.

8. The battery cell according to claim 1, characterized in that, The lower plastic includes a main body and a first side portion. The main body has a first side portion on each side in the first direction, and the first side portion has at least one second snap-fit ​​portion.

9. The battery cell according to claim 1, characterized in that, The material used for the first snap-fit ​​part includes at least one of polypropylene, polyethylene, polyimide, and polyethylene terephthalate.

10. The battery cell according to claim 1, characterized in that, Also includes: The electrode assembly includes an electrode body and an electrode tab, wherein the electrode tab is connected to the body along the second direction; The cover plate assembly further includes an electrode post, which is disposed on the cover plate and connected to the electrode lug.

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