Battery monomer, battery device and electric equipment

Abstract

The embodiment of the utility model provides a battery monomer, a battery device and electric equipment. The battery monomer comprises an electrode assembly, a shell and an insulating film, the outer surface of the shell comprises a third surface, two first surfaces and two second surfaces; the insulating film wraps the outer surface of the shell, the insulating film comprises a main body area and two ending areas, the two ending areas respectively cover the two second surfaces, each ending area comprises a first folding lug, a second folding lug and a third folding lug which are respectively in angled connection with the main body area, and the third folding lug is provided with a first edge and a second edge which are opposite in the first direction; the ending area is configured to form at least parts of the first folding lug, the second folding lug and the third folding lug through separation of the first edge and the second edge, the first edge extends in the direction away from the second edge, and the second edge extends in the third direction or extends in the direction away from the first edge. The risk of warping of the insulating film can be reduced.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery cell, a battery device, and an electrical appliance. Background Technology

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0003] The outer casing of a battery cell is usually wrapped with an insulating film. How to reduce the risk of the insulating film peeling off is a research direction in battery technology. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical appliance that can reduce the risk of insulation film peeling.

[0005] This application provides a battery cell including an electrode assembly, a housing, and an insulating film. The housing has a receiving cavity and an opening communicating with the receiving cavity. The electrode assembly is located in the receiving cavity. The outer surface of the housing includes a third surface, two first surfaces, and two second surfaces. The two first surfaces are arranged opposite to each other along a first direction, the two second surfaces are arranged opposite to each other along a second direction, and the third surface is arranged opposite to the opening along a third direction. The first direction, the second direction, and the third direction intersect each other. The insulating film wraps around the outer surface of the housing. The insulating film includes a main region and two terminal regions connected to the main region. The main region covers the two first surfaces and the third surface, and the two terminal regions respectively cover the two second surfaces. At least one terminal region includes components respectively connected to the main surface and the second surface. The body region comprises a first folded ear, a second folded ear, and a third folded ear connected at an angle. The first folded ear and the second folded ear are each stacked on the second surface at one end away from the opening. The third folded ear is located on the side of the first folded ear and the second folded ear that is at least partially away from the second surface. The third folded ear has a first edge and a second edge that are opposite to each other along a first direction. The tailing region is configured to separate the first edge and the second edge to form at least a portion of the first folded ear, the second folded ear, and the third folded ear. Along the direction from the opening to the third surface, the first edge extends in a direction away from the second edge, and the second edge extends in a third direction or in a direction away from the first edge.

[0006] In the above technical solution, in the battery cell of this embodiment, the first and second edges of the insulating film are configured to extend in a direction from the opening toward the third surface. The first edge extends away from the second edge. Thus, compared to the two cut edges extending in the third direction, the area of ​​the folded region of the first and second flaps away from the opening is smaller relative to the area of ​​the third flap. This smaller folded region reduces stress concentration and lowers the risk of the third flap lifting. Furthermore, with a smaller folded region, the effective bonding area of ​​the third flap is larger, further reducing the risk of the third flap lifting.

[0007] In some embodiments, along the direction from the opening to the third surface, both the first edge and the second edge gradually move away from each other and are arranged in a straight line.

[0008] In the above technical solution, not only is the area of ​​the folded area smaller, further reducing the risk of the third fold lifting, but the first and second edges, which are set in oblique straight lines, are easy to cut, improving processing efficiency.

[0009] In some embodiments, the area of ​​the first surface is greater than the area of ​​the second surface.

[0010] In the above technical solution, the finishing area wrapped by the insulating film is set on the second surface with a smaller area. The smaller area not only facilitates the folding of the first fold, the second fold, and the third fold, but also reduces the amount of insulating film used.

[0011] In some embodiments, the first surface and the third surface are connected to the second surface by curved transition sections, and the endpoints of the first edge and the second edge facing the third surface are both located on the second surface.

[0012] In the above technical solution, the endpoints of both the first edge and the second edge are set on the second surface. In the process of wrapping the insulating film, the rounded corner area formed by the intersection of the first surface, the second surface and the third surface is basically wrapped, reducing the possibility of the rounded corner area being exposed and improving the reliability of the insulating film wrapping.

[0013] In some embodiments, the second surface has four vertices, namely a first vertex, a second vertex, a third vertex, and a fourth vertex. The first vertex and the second vertex are located at one end where the opening is located, and the third vertex and the fourth vertex are located at one end where the third surface is located. The first vertex and the third vertex are arranged along a third direction, and the second vertex and the fourth vertex are arranged along a third direction. The endpoint adjacent to the third vertex is located on the side of the third vertex facing the second vertex, and / or the endpoint adjacent to the fourth vertex is located on the side of the fourth vertex facing the first vertex.

[0014] The above technical solution aims to further reduce the possibility of exposed rounded corner areas and improve the reliability of insulating film wrapping.

[0015] In some embodiments, the first surface and the third surface are connected by curved transition segments. Among the multiple curved transition segments between the first surface and the second surface, between the second surface and the third surface, and between the first surface and the third surface, the maximum radius of the curved transition segment is r, and the distance between the third vertex and the adjacent endpoint along the first direction is H1, where H1 and r satisfy: 2r / 3≤H1≤3r / 2; and / or, the distance between the third vertex and the adjacent endpoint along the third direction is H2, where H2 and H1 satisfy: H1≤H2≤2H1.

[0016] In the above technical solution, the value of H1 is limited to greater than or equal to 2r / 3 to further reduce the possibility of exposed rounded corner areas and improve the reliability of insulating film wrapping; the value of H1 is limited to less than or equal to 3r / 2 to make the size of the third fold at the cut endpoint along the first direction larger, and the folding area of ​​the first and second folds smaller, thereby increasing the effective bonding area. The value of H2 is limited to greater than or equal to H1 to further reduce the possibility of exposed rounded corner areas and improve the reliability of insulating film wrapping; the value of H2 is limited to less than or equal to 2H1 to make the portion of the third fold with the first and second edges larger along the third direction, thereby facilitating folding and reducing the possibility of the third fold being wrapped inside during folding.

[0017] In some embodiments, H1 and r satisfy: 2r / 3≤H1≤r.

[0018] In the above technical solution, the value of H1 is limited to be less than or equal to r, so that the size of the third fold ear at the end point along the first direction is larger, and the folding area of ​​the first fold ear and the second fold ear is smaller, thereby increasing the effective bonding area.

[0019] In some embodiments, H2 and H1 satisfy: H1≤H2≤1.5H1.

[0020] In the above technical solution, the value of H2 is limited to less than or equal to 1.5H1, so that the portion of the third folded ear with the first edge and the second edge has a larger dimension along the third direction, further reducing the possibility of being enclosed.

[0021] In some embodiments, the maximum dimension of the third folding lug along the first direction is H3, and the minimum dimension of the third folding lug along the first direction is H4, wherein H3 and H4 satisfy: H3 / 3≤H4≤2H3 / 3.

[0022] In the above technical solution, the value of H4 is set between H3 / 3 and 2H3 / 3, which reduces the phenomenon of inner wrapping of the third fold and also makes the insulating film have a larger bonding area.

[0023] In some embodiments, H3 and H4 satisfy: H3 / 3≤H4≤H3 / 2.

[0024] In the above technical solution, the value of H4 is limited to less than or equal to H3 / 2, which further reduces the phenomenon of inner wrapping of the third fold.

[0025] In some embodiments, the dimension of the first folding ear along the first direction is L1, the dimension of the second surface along the first direction is H0, and L1 and H0 satisfy: H0 / 2 < L1 < H0; and / or, the dimension of the second folding ear along the first direction is L2, the dimension of the second surface along the first direction is H0, and L2 and H0 satisfy: H0 / 2 < L2 < H0.

[0026] In the above technical solution, the values ​​of L1 and L2 are both limited to be greater than H0 / 2 so that the second surface has a better wrapping effect; the values ​​of L1 and L2 are both limited to be less than H0 so as to reduce the extension of the first and second folds to other surfaces, and also reduce the occurrence of folds that affect the bonding area and bulges.

[0027] In some embodiments, L1 and H0 satisfy: H0 / 2<L1≤2H0 / 3, and L2 and H0 satisfy: H0 / 2<L2≤2H0 / 3.

[0028] The above technical solution aims to reduce the amount of material used in the insulating film.

[0029] In some embodiments, the housing is rectangular.

[0030] The above technical solution further facilitates the wrapping of the insulating film.

[0031] Secondly, embodiments of this application also provide a battery device, including the aforementioned battery cell.

[0032] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery device, which is used to store electrical energy or provide electrical energy. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0034] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0035] Figure 2 This is a schematic diagram of the structure of a battery device provided in some embodiments of this application;

[0036] Figure 3 This is a schematic diagram of the structure of a battery cell assembly in a battery device provided in some embodiments of this application;

[0037] Figure 4 This is an exploded structural diagram of a battery cell provided in some embodiments of this application;

[0038] Figure 5 This is a schematic diagram of the structure of the casing of a battery cell provided in some embodiments of this application;

[0039] Figure 6 A schematic diagram of an insulating film forming a cutting line provided for some embodiments of this application (also showing a battery cell);

[0040] Figure 7 This is a schematic diagram of another structure for forming a cutting line in the insulating film according to some embodiments of this application (also showing a partial structure of a battery cell).

[0041] Figure 8 A schematic diagram of the structure of the insulating film and battery cell during the wrapping process provided in some embodiments of this application;

[0042] Figure 9 A schematic diagram of the structure of the insulating film and battery cell after encapsulation, provided in some embodiments of this application;

[0043] Figure 10 This is a schematic diagram illustrating another structure of the insulating film and battery cell after encapsulation, as provided in some embodiments of this application.

[0044] Figure 11 for Figure 10 Enlarged view of point A in the middle.

[0045] The reference numerals in the accompanying drawings for the specific embodiments are as follows:

[0046] 100. Vehicle; 200. Battery unit; 300. Controller; 400. Motor; 500. Battery cell; 600. Housing; 700. Battery cell assembly;

[0047] 1. Electrode assembly;

[0048] 21. Shell; 211. Receiving cavity; 212. Opening; 213. First surface; 214. Second surface; 2141. First vertex; 2142. Second vertex; 2143. Third vertex; 2144. Fourth vertex; 215. Third surface; 216. Curved transition section;

[0049] 22. End cap;

[0050] 3. Insulating film;

[0051] 31. Main area;

[0052] 32. Finishing area; 321. First fold; 322. Second fold; 323. Third fold; 326. First edge; 327. Second edge;

[0053] 4. Electrode terminals;

[0054] 5. Pressure relief mechanism;

[0055] X, first direction; Y, second direction; Z, third direction. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, 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.

[0057] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0058] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0059] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" 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 direct connection or an indirect connection through an intermediate medium; and 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 according to the specific circumstances.

[0060] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0061] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0062] In this application, "multiple" means two or more (including two).

[0063] In this application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc., and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto.

[0064] A single battery cell includes electrode components and an electrolyte. The electrode components include a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer, which is coated on the surface of the positive current collector. The positive current collector includes a positive electrode coating area and a positive electrode tab connected to the coating area. The coating area is coated with the positive active material layer, while the tab is not. Taking a lithium-ion battery cell as an example, the positive current collector can be made of aluminum, and the positive active material layer includes the positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer being coated on the surface of the negative electrode current collector. The negative electrode current collector includes a negative electrode coating area and a negative electrode tab connected to the negative electrode coating area. The negative electrode coating area is coated with the negative electrode active material layer, while the negative electrode tab is not coated with the negative electrode active material layer. The material of the negative electrode current collector can be copper, and the negative electrode active material layer includes negative electrode active material, which can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0065] As the outermost component of a battery cell, the blue film plays a crucial role in resisting impacts, reducing scratches, and providing dust and water protection. The blue film is typically wrapped in a U-shape, meaning that all surfaces except the end cap area are covered.

[0066] In some cases, the ends of the blue film are cut horizontally. Two parallel slits with a certain depth and a certain distance are cut into the bottom end of the U-shaped blue film, so that the cut area is divided into three parts: the upper part, the side part, and the lower part. The upper part is bonded to the outer shell during the downward pressing of the upper pressure plate. The lower part is bonded to the outer shell and the upper part that has already been bonded to the outer shell during the upward pressing of the lower pressure plate. Then, the side roller rolls to the right to press the side part to bond it to the upper and lower parts that have already been bonded, so that the blue film wraps the battery cell.

[0067] However, the horizontal cutting method will cause a large overlap area on the side of the upper and lower parts of the blue film near the side when wrapping the battery cell. After the overlap area is bonded to the side part, a large stress concentration will occur, which will increase the risk of lifting. Since the overlap area is bonded to the side part, it will also reduce the bonding area between the side part and the upper and lower parts to be bonded, resulting in the effective bonding area of ​​the side part being reduced to a small rectangular area. This will further aggravate the lifting of the side part.

[0068] In view of this, this application provides a battery cell in which the cutting edge of the terminal region is configured such that, instead of extending along a third direction, the first edge extends away from the second edge in the direction pointing from the opening to the third surface. In this way, compared to the two cutting edges extending along the third direction, the area of ​​the folded regions of the first and second folded edges, which are gradually increasing in distance, is smaller relative to the area of ​​the third folded edge. This smaller folded area reduces stress concentration and lowers the risk of the third folded edge lifting. Furthermore, with the reduced area of ​​the folded region, the effective bonding area of ​​the third folded edge is larger, further reducing the risk of the third folded edge lifting.

[0069] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0070] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0071] Figure 1 This is a structural schematic diagram of a vehicle 100 provided in some embodiments of this application.

[0072] like Figure 1 As shown, a battery device 200 is provided inside the vehicle 100. The battery device 200 can be located at the bottom, front, or rear of the vehicle 100. The battery device 200 can be used to power the vehicle 100; for example, the battery device 200 can serve as the operating power source for the vehicle 100.

[0073] The vehicle 100 may also include a controller 300 and a motor 400. The controller 300 is used to control the battery device 200 to supply power to the motor 400, for example, for the power needs of the vehicle 100 during startup, navigation and driving.

[0074] In some embodiments of this application, the battery device 200 can not only serve as the operating power source for the vehicle 100, but also as the driving power source for the vehicle 100, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 100.

[0075] Figure 2 This is a schematic diagram of the structure of the battery device 200 provided in some embodiments of this application; Figure 3 This is a schematic diagram of the structure of a battery cell assembly in a battery device provided in some embodiments of this application.

[0076] like Figure 2 and Figure 3 As shown, the battery device 200 includes one or more battery cell assemblies 700 for providing voltage and capacity. The battery cell assembly 700 may include multiple battery cells 500, which are connected in series, parallel, or mixed connections via a busbar.

[0077] In some embodiments, the battery cell assembly 700 is typically formed by arranging a plurality of battery cells 500; as an example, the battery cell assembly 700 can be a battery module, which is formed by arranging and fixing a plurality of battery cells 500 into a single module. As an example, a battery module can be formed by bundling a plurality of battery cells 500 together with cable ties.

[0078] In some embodiments, the battery device 200 may be a battery pack, which includes a housing 600 and one or more battery cell assemblies 700, the battery cell assemblies 700 being housed in the housing 600.

[0079] As an example, the battery cell assembly 700 can be a battery module, and the battery cell assembly 700 can be housed in the housing 600 by fixing the battery module in the housing 600.

[0080] As an example, the battery cell assembly 700 can also be housed in the housing 600 by directly fixing multiple battery cells 500 to the housing 600.

[0081] As an example, the housing 600 may include a first housing and a second housing. The first housing and the second housing are fastened together to form a closed space inside the housing 600 to house the battery cell assembly 700. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing may be a top cover or a bottom plate.

[0082] As an example, the housing 600 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 600 forms an enclosed space to house the battery cell assembly 700.

[0083] As an example, the housing 600 can be part of the chassis structure of the vehicle 100. For example, the top cover of the housing 600 can be at least part of the floor of the vehicle 100, or the frame of the housing 600 can be at least part of the crossbeams and longitudinal beams of the vehicle 100.

[0084] In some embodiments, battery device 200 refers to an energy storage device, which includes a housing 600, and at least one side of the housing 600 has a door. The energy storage device includes energy storage containers, energy storage cabinets, etc.

[0085] Figure 4 This is an exploded structural diagram of a battery cell provided in some embodiments of this application; Figure 5 This is a schematic diagram of the structure of the casing of a battery cell provided in some embodiments of this application; Figure 6 A schematic diagram of an insulating film forming a cutting line provided in some embodiments of this application; Figure 7 This is a schematic diagram of another structure for forming a cutting line in an insulating film, provided in some embodiments of this application. Figure 8 A schematic diagram of the structure of the insulating film and battery cell during the wrapping process provided in some embodiments of this application; Figure 9 This is a schematic diagram of the structure of the insulating film and battery cell after encapsulation, as provided in some embodiments of this application.

[0086] like Figures 4-9As shown, this application also provides a battery cell 500, including an electrode assembly 1, a housing 21, and an insulating film 3. The housing 21 has a receiving cavity 211 and an opening 212 communicating with the receiving cavity 211. The electrode assembly 1 is located in the receiving cavity 211. The outer surface of the housing 21 includes a third surface 215, two first surfaces 213, and two second surfaces 214. The two first surfaces 213 are arranged opposite to each other along a first direction X, and the two second surfaces 214 are arranged opposite to each other along a second direction Y. The third surface 215 and the opening 212 are arranged opposite to each other along a third direction Z. The first direction X, the second direction Y, and the third direction Z intersect each other. The insulating film 3 is wrapped around the outer surface of the housing 21. The insulating film 3 includes a main body region 31 and two terminal regions 32 connected to the main body region 31. The main body region 31 covers two first surfaces 213 and a third surface 215. The two terminal regions 32 cover two second surfaces 214 respectively. At least one terminal region 32 includes a first fold 321, a second fold 322, and a third fold 323 that are respectively connected to the main body region 31 at an angle. The first fold 321 and the second fold 322 are each stacked on the second surface 214 at one end away from the opening 212. The third fold 323 is located on the first fold 321. The third fold 323 has at least a portion of each of the second and second folds 322 facing away from the second surface 214, and has a first edge 326 and a second edge 327 facing away from each other along the first direction X. The tailing region 32 is configured to separate the first fold 321, the second fold 322 and the third fold 323 by the first edge 326 and the second edge 327, and the first edge 326 extends away from the second edge 327 in the direction pointing from the opening 212 toward the third surface 215. The second edge 327 extends along the third direction Z or in the direction away from the first edge 326.

[0087] In this embodiment, the end cap 22 refers to a component that covers the opening 212 of the housing 21 to isolate the internal environment of the battery cell 500 from the external environment. The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. Optionally, the end cap 22 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 22 is not easily deformed under pressure and impact, allowing the battery cell 500 to have higher structural strength. Functional components such as electrode terminals 4 can be provided on the end cap 22. The electrode terminals 4 can be used to electrically connect with the electrode assembly 1 for outputting or inputting electrical energy into the battery cell 500. In some embodiments, the end cap 22 can also be provided with a pressure relief mechanism 5 for releasing internal pressure when the internal pressure or temperature of the battery cell 500 reaches a threshold. The material of the end cap 22 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment does not impose any special limitations on this. In some embodiments, an insulating element may be provided on the inner side of the end cap 22. The insulating element can be used to isolate the electrical connection components within the housing 21 from the end cap 22 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0088] The housing 21 is a component used to cooperate with the end cap 22 to form the internal environment of the battery cell 500. This internal environment can accommodate the electrode assembly 1, electrolyte, and other components. The housing 21 and end cap 22 can be independent components, or they can be integrated. Specifically, the end cap 22 and housing 21 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 21, the end cap 22 closes the opening 212 of the housing 21. The housing 21 can be cuboid in shape. The housing 21 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, or plastic.

[0089] Electrode assembly 1 is the component in the battery cell 500 where the electrochemical reaction occurs. The casing 21 may contain one or more electrode assemblies 1. Electrode assembly 1 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of electrode assembly 1, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery device 200, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals to form a current loop.

[0090] For example, the first surface 213, the second surface 214, and the third surface 215 are all planar. In this embodiment, the first surface 213 can be the largest side surface of the housing 21, and the third surface 215 can be regarded as the bottom surface of the housing 21.

[0091] Optionally, the first direction X, the second direction Y, and the third direction Z are all perpendicular to each other.

[0092] In this embodiment, the insulating film 3 can be a blue film. The insulating film 3 includes a main body region 31 and a termination region 32 connected to the main body region 31. The main body region 31 and the termination region 32 can be integrally formed or connected by heat fusion. The two termination regions 32 are disposed at both ends of the main body region 31 along the second direction Y.

[0093] For example, when the insulating film 3 wraps the housing 21, it is a single sheet of film structure. First, the insulating film 3 is bent to form a U-shaped structure that matches the shapes of the two first surfaces 213 and the third surface 215, such as... Figure 6 As shown, the bottom wall of the U-shaped structure covers the third surface 215, and the two side walls of the U-shaped structure cover the two first surfaces 213 respectively. The part of the U-shaped structure covering the first surface 213 and the third surface 215 is the main body area 31. The U-shaped structure protrudes from both ends of the shell 21 along the second direction Y, and the two parts of the U-shaped structure protruding from both ends of the shell 21 are two tailing areas 32.

[0094] The finishing area 32 is cut, and the portion of the finishing area 32 that protrudes from the third surface 215 is cut, forming two slits, as shown. Figure 7 As shown, the two slits are spaced a certain distance apart along the first direction X, and the distance between the two slits gradually increases from the direction away from the second surface 214 to the direction closer to the second surface 214.

[0095] Then during the folding process, such as Figure 8 As shown, firstly, the portion of the finishing area 32 protruding from one of the first surfaces 213 is folded towards the second surface 214 to form a first folded ear 321. Then, the portion of the finishing area 32 protruding from the other first surface 213 is folded towards the second surface 214 to form a second folded ear 322. The second folded ear 322 is attached to the second surface 214 and the first folded ear 321. Finally, the portion of the finishing area 32 protruding from the third surface 215 is folded towards the second surface 214 to form a third folded ear 323. The third folded ear 323 is attached to the first folded ear 321 and the second folded ear 322, thus completing the bonding of the second surface 214. Figure 9 As shown.

[0096] Since the first edge 326 and the second edge 327 are located in the portion of the finishing area 32 that protrudes from the third surface 215, and the distance from the opening 212 to the third surface 215 gradually increases, during the folding process, the ends of the first folding lug 321 and the second folding lug 322 near the third surface 215 respectively form folding areas, such as... Figure 9 As shown by the dashed line, the third fold 323 covers the folded area, and the area of ​​the third fold 323 that does not cover the folded area is the effective bonding area of ​​the third fold 323.

[0097] The first edge 326 in this embodiment can be either oblique or curved.

[0098] The separation endpoint of the first edge 326 in this embodiment can be located on the second surface 214, or on the curved transition section 216 between the third surface 215 and the second surface 214, or at the vertex region where the first surface 213, the second surface 214 and the third surface 215 intersect.

[0099] The finishing area 32 is configured to be divided by the first edge 326 and the second edge 327 to form at least a portion of each of the first fold 321, the second fold 322, and the third fold 323. This means that, depending on the endpoint position of the cut of the first edge 326 and the second edge 327, the first fold 321, the second fold 322, and the third fold 323 can be formed entirely by the division of the first edge 326 and the second edge 327, or only partially by the division of the first edge 326 and the second edge 327. For example, if the cut endpoint is at the vertex region where the first surface 213, the second surface 214, and the third surface 215 intersect, then the first fold 321, the second fold 322, and the third fold 323 can be formed entirely by the division of the first edge 326 and the second edge 327. When the cutting endpoint is within the second surface 214, the first edge 326 can only divide to form a portion of the first fold 321, a portion of the second fold 322, and a portion of the third fold 323, and a portion of the first fold 321 and a portion of the second fold 322 and the third fold 323 can be located on the same surface.

[0100] In the battery cell 500 of this embodiment, the first edge 326 and the second edge 327 of the insulating film 3 are configured to point from the opening 212 toward the third surface 215. The first edge 326 extends away from the second edge 327. As a result, compared to the two cut edges extending in the third direction Z, the area of ​​the folded region of the first flap 321 and the second flap 322 is smaller than the area of ​​the third flap 323. The smaller folded region can reduce stress concentration at this point and reduce the risk of the third flap 323 lifting. Furthermore, with the reduced area of ​​the folded region, the effective bonding area of ​​the third flap 323 is larger, further reducing the risk of the third flap 323 lifting.

[0101] In some embodiments, along the direction from the opening 212 toward the third surface 215, the first edge 326 and the second edge 327 are both gradually moving away from each other and arranged in an oblique straight line.

[0102] Optionally, the first edge 326 and the second edge 327 are symmetrically arranged.

[0103] By setting the first edge 326 and the second edge 327 to gradually move away from each other, not only is the area of ​​the folded region smaller, further reducing the risk of the third fold 323 lifting, but the first edge 326 and the second edge 327, which are set in oblique straight lines, are easy to cut and improve processing efficiency.

[0104] In some embodiments, the area of ​​the first surface 213 is greater than the area of ​​the second surface 214.

[0105] This configuration allows the finishing area 32 of the insulating film 3 to be located on the smaller second surface 214. The smaller area not only facilitates the folding of the first fold 321, the second fold 322, and the third fold 323, but also reduces the amount of insulating film 3 used.

[0106] Figure 10 This is another structural diagram of the insulating film and battery cell provided in some embodiments of this application after encapsulation.

[0107] Please see Figure 5 and Figure 10 In some embodiments, the first surface 213 and the third surface 215 are respectively connected to the second surface 214 through a curved transition section 216, and the endpoints of the first edge 326 and the second edge 327 facing the third surface 215 are both located on the second surface 214.

[0108] For example, the first surface 213, the second surface 214 and the third surface 215 are all planar.

[0109] By placing the endpoints of both the first edge 326 and the second edge 327 on the second surface 214, the rounded corner area formed by the intersection of the first surface 213, the second surface 214, and the third surface 215 is essentially covered during the wrapping of the insulating film 3. This reduces the possibility of the rounded corner area being exposed and improves the reliability of the insulating film 3 wrapping. Furthermore, since the rounded corner area is prone to poor adhesion, this arrangement ensures that the endpoints are adhered to the second surface 214 as much as possible, thereby improving the reliability of the adhesion.

[0110] In some embodiments, the second surface 214 has four vertices, namely a first vertex 2141, a second vertex 2142, a third vertex 2143, and a fourth vertex 2144. The first vertex 2141 and the second vertex 2142 are located at one end where the opening 212 is located, and the third vertex 2143 and the fourth vertex 2144 are located at one end where the third surface 215 is located. The first vertex 2141 and the third vertex 2143 are arranged along the third direction Z, and the second vertex 2142 and the fourth vertex 2144 are arranged along the third direction Z. The endpoint adjacent to the third vertex 2143 is located on the side of the third vertex 2143 facing the second vertex 2142, and / or the endpoint adjacent to the fourth vertex 2144 is located on the side of the fourth vertex 2144 facing the first vertex 2141.

[0111] The second surface 214 in this embodiment can be rectangular.

[0112] In this embodiment, the endpoint adjacent to the third vertex 2143 is located on the side of the third vertex 2143 facing the second vertex 2142, such as... Figure 10 As shown, if the first vertex 2141 and the third vertex 2143 are on top, and the second vertex 2142 and the fourth vertex 2144 are on the bottom, then the endpoint is located diagonally below the third vertex 2143.

[0113] In this embodiment, the endpoint adjacent to the fourth vertex 2144 is located on the side of the fourth vertex 2144 facing the first vertex 2141. If the first vertex 2141 and the third vertex 2143 are above, and the second vertex 2142 and the fourth vertex 2144 are below, then the endpoint is located diagonally above the fourth vertex 2144.

[0114] This design further reduces the possibility of exposed rounded corner areas and improves the reliability of the insulating film 3 wrapping.

[0115] In some embodiments, the first surface 213 and the third surface 215 are connected by curved transition segments. Among the multiple curved transition segments between the first surface 213 and the second surface 214, between the second surface 214 and the third surface 215, and between the first surface 213 and the third surface 215, the maximum radius of the curved transition segment is r, and the distance between the third vertex 2143 and the adjacent endpoint along the first direction X is H1, where H1 and r satisfy: 2r / 3≤H1≤3r / 2; and / or, the distance between the third vertex 2143 and the adjacent endpoint along the third direction Z is H2, where H2 and H1 satisfy: H1≤H2≤2H1.

[0116] In this embodiment, the value of H1 can be 4r / 6, 5r / 6, r, 7r / 6, 8r / 6, or 3r / 2.

[0117] In this embodiment, the value of H2 can be H1, 1.2 H1, 1.4 H1, 1.6 H1, 1.8 H1, or 2H1.

[0118] Furthermore, the value of H1 is 1 mm, and the value of H2 is 2 mm.

[0119] The value of H1 is limited to greater than or equal to 2r / 3 to further reduce the possibility of exposed rounded corner areas and improve the reliability of the insulation film 3 wrapping; the value of H1 is limited to less than or equal to 3r / 2 so that the size of the third fold 323 at the end point along the first direction X is larger, and the folding area of ​​the first fold 321 and the second fold 322 is smaller, thereby increasing the effective bonding area.

[0120] The value of H2 is restricted to be greater than or equal to H1 to further reduce the possibility of exposed rounded corner areas and improve the reliability of the insulation film 3 wrapping; the value of H2 is restricted to be less than or equal to 2H1 so that the portion of the third fold 323 with the first edge 326 and the second edge 327 has a larger dimension along the third direction Z, thereby facilitating folding and reducing the possibility of being wrapped inside during folding.

[0121] In some embodiments, H1 and r satisfy: 2r / 3≤H1≤r.

[0122] The value of H1 is restricted to be less than or equal to r so that the third fold 323 has a larger dimension at the end point along the first direction X, and the folded areas of the first fold 321 and the second fold 322 are smaller, thereby increasing the effective bonding area.

[0123] In some embodiments, H2 and H1 satisfy: H1≤H2≤1.5H1.

[0124] The value of H2 is restricted to be less than or equal to 1.5H1 so that the portion of the third fold 323 with the first edge 326 and the second edge 327 has a larger dimension along the third direction Z, further reducing the possibility of being enclosed.

[0125] Please see Figure 9 In some embodiments, the maximum dimension of the third folding lug 323 along the first direction X is H3, and the minimum dimension of the third folding lug 323 along the first direction X is H4. H3 and H4 satisfy: H3 / 3≤H4≤2H3 / 3.

[0126] Optionally, the value of H3 can be H3 / 3, H3 / 2, or 2H3 / 3.

[0127] In this embodiment, the minimum dimension of the third folding lug 323 along the first direction X is the dimension of the third folding lug 323 along the first direction X at the end (cutting start point) of the first edge 326 and the second edge 327 facing the opening 212.

[0128] The distance H4 between the cutting starting points of the first edge 326 and the second edge 327 of the insulating film 3 should not be too large. If the distance is too large, when the pressure plate presses down on the first fold 321 and the second fold 322 of the insulating film 3, the third fold 323 will also sag due to the excessively long cut height. The sag of the third fold 323 will stick together with the first fold 321 and the second fold 322, resulting in the third fold 323 being wrapped inside. In this case, the insulating film 3 will not achieve the desired wrapping effect when the third fold 323 is subsequently rolled by the roller. The size of H4 should also not be too small. The size of H4 will affect the effective bonding area of ​​the third fold 323. The smaller the value of H4, the larger the folded area of ​​the first fold 321 and the second fold 322 will be, and the smaller the effective bonding area of ​​the third fold 323 will be, thus increasing the risk of the insulating film lifting.

[0129] Therefore, the value of H4 is set between H3 / 3 and 2H3 / 3, which reduces the phenomenon of inner wrapping of the third fold 323 and also makes the insulating film have a larger bonding area.

[0130] In some embodiments, H3 and H4 satisfy: H3 / 3≤H4≤H3 / 2.

[0131] By restricting the value of H4 to less than or equal to H3 / 2, the phenomenon of inner wrapping of the third fold 323 is further reduced.

[0132] Please see Figure 5 and Figure 8In some embodiments, the first folding ear 321 has a dimension of L1 along the first direction X, and the second surface 214 has a dimension of H0 along the first direction X. L1 and H0 satisfy: H0 / 2 < L1 < H0; the second folding ear 322 has a dimension of L2 along the first direction X, and the second surface 214 has a dimension of H0 along the first direction X. L2 and H0 satisfy: H0 / 2 < L2 < H0.

[0133] Optionally, the value of L1 can be 6H0 / 10, 7H0 / 10, 8H0 / 10 or 9H0 / 10.

[0134] Optionally, the value of L2 can be 6H0 / 10, 7H0 / 10, 8H0 / 10 or 9H0 / 10.

[0135] The values ​​of L1 and L2 are both limited to be greater than H0 / 2 so that the second surface 214 has a better wrapping effect; the values ​​of L1 and L2 are both limited to be less than H0 so as to reduce the situation where the first fold 321 and the second fold 322 extend to other surfaces, and also reduce the situation where folding occurs and affects the bonding area and bulging.

[0136] In some embodiments, L1 and H0 satisfy: H0 / 2 < L1 ≤ 2H0 / 3, and L2 and H0 satisfy: H0 / 2 < L2 ≤ 2H0 / 3.

[0137] The values ​​of L1 and L2 are limited to less than or equal to 2H0 / 3 to reduce the amount of material used in the insulating film.

[0138] In some embodiments, the housing 21 is rectangular.

[0139] In this embodiment, the housing 21 is rectangular, meaning that the third surface 215, the two first surfaces 213, and the two second surfaces 214 are all planar. However, adjacent surfaces can be smoothly transitioned by a curved transition section 216 as described above, or they can be connected at right angles within the allowable range of machining errors.

[0140] This design further facilitates the wrapping of the insulating film 3.

[0141] This application also provides a battery device 200, which includes the aforementioned battery cell 500.

[0142] This application embodiment also provides an electrical device, including the battery device 200 described above, which is used to store electrical energy or provide electrical energy.

[0143] Please see Figures 4-11This application also provides a battery cell 500, including an electrode assembly 1, a housing 21, and an insulating film 3. The housing 21 has a receiving cavity 211 and an opening 212 communicating with the receiving cavity 211. The electrode assembly 1 is located in the receiving cavity 211. The outer surface of the housing 21 includes a third surface 215, two first surfaces 213, and two second surfaces 214. The two first surfaces 213 are arranged opposite to each other along a first direction X, and the two second surfaces 214 are arranged opposite to each other along a second direction Y. The third surface 215 and the opening 212 are arranged opposite to each other along a third direction Z. The first direction X, the second direction Y, and the third direction Z intersect each other. The insulating film 3 is wrapped around the outer surface of the housing 21. The insulating film 3 includes a main body region 31 and two terminal regions 32 connected to the main body region 31. The main body region 31 covers two first surfaces 213 and a third surface 215. The two terminal regions 32 cover two second surfaces 214 respectively. At least one terminal region 32 includes a first fold 321, a second fold 322, and a third fold 323 that are respectively connected to the main body region 31 at an angle. The first fold 321 and the second fold 322 are each stacked on the second surface 214 at one end away from the opening 212. The third fold 323 is located on the first fold 321. The first and second folded ears 322 each have at least a portion facing away from the second surface 214. The third folded ear 323 has a first edge 326 and a second edge 327 facing away from each other along a first direction X. The tailing region 32 is configured to separate at least a portion of the first folded ear 321, the second folded ear 322, and the third folded ear 323 through the first edge 326 and the second edge 327, pointing towards the third surface 215 along the opening 212. The first edge 326 extends away from the second edge 327, and the second edge 327 extends along a third direction Z or away from the first edge 326. The area of ​​the first surface 213 is larger than the area of ​​the second surface 214. The first surface 213 and the third surface 215 are respectively connected to the second surface 214 through curved transition sections 216. The endpoints of the first edge 326 and the second edge 327 facing the third surface 215 are both located on the second surface 214. The second surface 214 has four vertices: a first vertex 2141, a second vertex 2142, a third vertex 2143, and a fourth vertex 2144. The first vertex 2141 and the second vertex 2142 are located at the end where the opening 212 is located, and the third vertex 2143 and the fourth vertex 2144 are located at the end where the third surface 215 is located. The first vertex 2141 and the third vertex 2143 are arranged along the third direction Z, and the second vertex 2142 and the fourth vertex 2144 are arranged along the third direction Z. The endpoint adjacent to the third vertex 2143 is located on the side of the third vertex 2143 facing the second vertex 2142, and the endpoint adjacent to the fourth vertex 2144 is located on the side of the fourth vertex 2144 facing the first vertex 2141.

[0144] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, 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. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell, characterized in that, include: Electrode assembly; A housing having a receiving cavity and an opening communicating with the receiving cavity, the electrode assembly being located in the receiving cavity, the outer surface of the housing including a third surface, two first surfaces and two second surfaces, the two first surfaces being arranged opposite to each other along a first direction, the two second surfaces being arranged opposite to each other along a second direction, the third surface being arranged opposite to the opening along a third direction, and the first direction, the second direction and the third direction intersecting each other in pairs; An insulating film is wrapped around the outer surface of the housing. The insulating film includes a main area and two terminal areas connected to the main area. The main area covers the two first surfaces and the third surface. The two terminal areas cover the two second surfaces respectively. At least one terminal area includes a first fold, a second fold, and a third fold that are respectively connected to the main area at an angle. The ends of the first fold and the second fold that are away from the opening are stacked on the second surface. The third fold is located on the side of the first fold and the second fold that are at least partially away from the second surface. The third fold has a first edge and a second edge that are opposite to each other along the first direction. The terminal area is configured to separate the first edge and the second edge to form at least a portion of the first fold, the second fold, and the third fold. In the direction from the opening to the third surface, the first edge extends away from the second edge, and the second edge extends along the third direction or in a direction away from the first edge.

2. The battery cell according to claim 1, characterized in that, Along the direction from the opening toward the third surface, the first edge and the second edge gradually move away from each other and are arranged in an oblique straight line.

3. The battery cell according to claim 1, characterized in that, The area of ​​the first surface is greater than the area of ​​the second surface.

4. The battery cell according to claim 1, characterized in that, The first surface and the third surface are respectively connected to the second surface through curved transition sections, and the endpoints of the first edge and the second edge facing the third surface are both located on the second surface.

5. The battery cell according to claim 4, characterized in that, The second surface has four vertices, namely a first vertex, a second vertex, a third vertex, and a fourth vertex. The first vertex and the second vertex are located at one end where the opening is located, and the third vertex and the fourth vertex are located at one end where the third surface is located. The first vertex and the third vertex are arranged along the third direction, and the second vertex and the fourth vertex are arranged along the third direction. The endpoint adjacent to the third vertex is located on the side of the third vertex facing the second vertex, and / or the endpoint adjacent to the fourth vertex is located on the side of the fourth vertex facing the first vertex.

6. The battery cell according to claim 5, characterized in that, The first surface and the third surface are connected by the curved transition segment. Among the multiple curved transition segments between the first surface and the second surface, between the second surface and the third surface, and between the first surface and the third surface, the maximum radius of the curved transition segment is r. The distance between the third vertex and the adjacent endpoint along the first direction is H1. H1 and r satisfy: 2r / 3≤H1≤3r / 2; and / or, the distance between the third vertex and the adjacent endpoint along the third direction is H2. H2 and H1 satisfy: H1≤H2≤2H1.

7. The battery cell according to claim 6, characterized in that, H1 and r satisfy: 2r / 3≤H1≤r.

8. The battery cell according to claim 6, characterized in that, H2 and H1 satisfy: H1≤H2≤1.5H1.

9. The battery cell according to any one of claims 1-8, characterized in that, The maximum dimension of the third folded ear along the first direction is H3, and the minimum dimension of the third folded ear along the first direction is H4. H3 and H4 satisfy: H3 / 3≤H4≤2H3 / 3.

10. The battery cell according to claim 9, characterized in that, H3 and H4 satisfy the condition: H3 / 3≤H4≤H3 / 2.

11. The battery cell according to any one of claims 1-8, characterized in that, The dimension of the first folded ear along the first direction is L1, and the dimension of the second surface along the first direction is H0. The L1 and the H0 satisfy: H0 / 2 < L1 < H0; And / or, The second folded ear has a dimension of L2 along the first direction, and the second surface has a dimension of H0 along the first direction. L2 and H0 satisfy: H0 / 2 < L2 < H0.

12. The battery cell according to claim 11, characterized in that, The L1 and H0 satisfy: H0 / 2<L1≤2H0 / 3, and the L2 and H0 satisfy: H0 / 2<L2≤2H0 / 3.

13. The battery cell according to claim 11, characterized in that, The shell is rectangular in shape.

14. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-13.

15. An electrical appliance, characterized in that, Includes the battery device as described in claim 14, the battery device being used to store electrical energy or provide electrical energy.

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