Battery cell, battery device, and electric device

Abstract

The embodiment of the utility model provides a battery monomer, a battery device and a power utilization device, the battery monomer comprises an electrode assembly and a shell, the shell accommodates the electrode assembly, the shell comprises a top wall, a bottom wall and a plurality of side walls, the top wall and the bottom wall are oppositely arranged along a first direction, two opposite ends of each side wall along the first direction are respectively connected to the top wall and the bottom wall, and the top wall, the bottom wall and the plurality of side walls are formed by bending a plate and are welded and connected at abutted seams. The production efficiency of the battery monomer can be improved.

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 device. 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] In the development of battery technology, improving the production efficiency of individual battery cells is a research direction. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical device that can improve the production efficiency of battery cells.

[0005] This application provides a battery cell, which includes an electrode assembly and a housing. The housing accommodates the electrode assembly and includes a top wall, a bottom wall, and multiple side walls. The top wall and the bottom wall are arranged opposite each other along a first direction. The two ends of each side wall that are opposite to each other along the first direction are respectively connected to the top wall and the bottom wall. The top wall, the bottom wall, and the multiple side walls are formed by bending a single sheet of material and welded together at the joint.

[0006] In the above technical solution, the battery cell casing of this application embodiment is formed by bending a single sheet of material to create the top wall, bottom wall, and multiple side walls. This reduces the total weld path at the seams compared to welding the top and bottom sheets separately to the central frame, thus improving the welding efficiency of the casing and consequently increasing the production efficiency of the battery cell. Furthermore, since it is formed from a single sheet of material, it offers better dimensional compatibility compared to multiple components, improving the welding yield.

[0007] In some embodiments, the welds formed at the joints are all located at the edges of the outer casing.

[0008] In the above technical solution, setting the weld seam at the edge of the shell not only facilitates the cutting of the sheet metal, but also reduces the number of weld seams formed.

[0009] In some embodiments, a portion of the weld formed at the joint is located on the sidewall or the bottom wall.

[0010] In the above technical solution, placing some welds on the side wall or bottom wall can reduce weld cracking caused by the expansion fatigue of the electrode assembly.

[0011] In some embodiments, the plurality of sidewalls include a first sidewall and a second sidewall disposed opposite to each other along a second direction, and a third sidewall and a fourth sidewall disposed opposite to each other along a third direction. The first direction, the second direction and the third direction intersect each other, and the area of ​​the first sidewall or the second sidewall is smaller than the area of ​​the third sidewall or the fourth sidewall.

[0012] In the above technical solution, multiple sidewalls are configured to include a first sidewall, a second sidewall, a third sidewall, and a fourth sidewall. The outer shell shape of this type of battery cell is relatively regular, which is convenient for cutting sheet metal and welding, and the welding path is relatively short.

[0013] In some embodiments, the battery cell further includes a first electrode terminal and a second electrode terminal; both the first electrode terminal and the second electrode terminal are disposed on the top wall or the bottom wall, or the first electrode terminal is disposed on the first side wall and the second electrode terminal is disposed on the second side wall.

[0014] In the above technical solution, the first electrode terminal and the second electrode terminal are located in other positions besides the third and fourth sidewalls, which facilitates connection with the internal electrode assembly.

[0015] In some embodiments, the third sidewall, top wall, fourth sidewall, and bottom wall are bent and connected in sequence, or the third sidewall, bottom wall, fourth sidewall, and top wall are bent and connected in sequence; the first sidewall and the second sidewall are bent and connected to the two ends of the third sidewall that are opposite to each other along the second direction, or the first sidewall and the second sidewall are bent and connected to the two ends of the fourth sidewall that are opposite to each other along the second direction.

[0016] In the above technical solution, the weld seam of the outer shell is located at the edge, which not only facilitates the cutting of the sheet metal, but also results in fewer weld seams.

[0017] In some embodiments, the third sidewall, top wall, fourth sidewall, and bottom wall are bent and connected in sequence, or the third sidewall, bottom wall, fourth sidewall, and top wall are bent and connected in sequence; the first sidewall is bent and connected to one of the third sidewall and the fourth sidewall, and the second sidewall is bent and connected to the other of the third sidewall and the fourth sidewall.

[0018] In the above technical solution, the weld seam of the outer shell is located at the edge, which is convenient for cutting, and the number of weld seams is small.

[0019] In some embodiments, a portion of the third sidewall, top wall, fourth sidewall, bottom wall, and another portion of the third sidewall are sequentially bent and connected, and the first sidewall and the second sidewall are respectively bent and connected to opposite ends of the fourth sidewall along the second direction.

[0020] In the above technical solution, placing the weld on the third sidewall can alleviate the problem of weld cracking caused by the expansion fatigue of the electrode assembly.

[0021] In some embodiments, the third sidewall, top wall, fourth sidewall, and bottom wall are bent and connected in sequence, or the third sidewall, bottom wall, fourth sidewall, and top wall are bent and connected in sequence; a portion of the first sidewall is bent and connected to the third sidewall, another portion of the first sidewall is bent and connected to the fourth sidewall, a portion of the second sidewall is bent and connected to the third sidewall, and another portion of the second sidewall is bent and connected to the fourth sidewall.

[0022] In the above technical solution, setting the weld on the first sidewall and the second sidewall can alleviate the problem of weld cracking caused by the expansion fatigue of the electrode assembly.

[0023] In some embodiments, the battery cell is a prismatic battery cell.

[0024] In the above technical solution, the outer shell shape of the square battery cell is relatively regular, which makes it easy to cut the sheet metal and also easy to weld, and the welding path is relatively short.

[0025] In some embodiments, the wall thickness of the outer shell is h, where h satisfies: 0.2mm≤h≤0.9mm.

[0026] In the above technical solution, limiting the wall thickness of the outer casing to greater than or equal to 0.2 mm can ensure that the structural strength of the outer casing meets the usage requirements; limiting the wall thickness of the outer casing to less than or equal to 0.9 mm can improve the volumetric energy density and gravimetric energy density of the battery cell under the same external dimensions.

[0027] In some embodiments, h satisfies: 0.3mm ≤ h ≤ 0.5mm.

[0028] In the above technical solution, limiting the wall thickness of the outer casing to greater than or equal to 0.3 mm can further improve the structural strength of the outer casing; limiting the wall thickness of the outer casing to less than or equal to 0.5 mm can further improve the volumetric energy density and gravimetric energy density of the battery cell under the same external dimensions.

[0029] Secondly, embodiments of this application also provide a battery device, including the aforementioned battery cell.

[0030] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery device, which is used to provide electrical energy. Attached Figure Description

[0031] 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.

[0032] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0033] Figure 2 This is a schematic diagram of the structure of a battery device provided in some embodiments of this application;

[0034] 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;

[0035] Figure 4 This is a schematic diagram of the structure of the outer casing of a battery cell provided in some embodiments of this application;

[0036] Figure 5 This is a schematic diagram of the casing of a battery cell provided in some embodiments of this application in an unbent state;

[0037] Figure 6 This is a schematic diagram of another structure of the casing of a battery cell provided in some embodiments of this application in an unbent state;

[0038] Figure 7 This is a schematic diagram of another structure of the casing of a battery cell provided in some embodiments of this application in an unbent state;

[0039] Figure 8 This is another structural schematic diagram of the casing of a battery cell in an unbent state, provided in some embodiments of this application;

[0040] Figure 9 This is another structural schematic diagram of the casing of a battery cell in an unbent state, provided in some embodiments of this application;

[0041] Figure 10 This is another structural schematic diagram of the casing of a battery cell provided in some embodiments of this application in an unbent state.

[0042] The reference numerals in the accompanying drawings for the specific embodiments are as follows:

[0043] 1. Vehicle; 2. Battery unit; 3. Controller; 4. Motor; 5. Battery cell; 6. Housing; 7. Battery cell assembly; 71. Busbar component;

[0044] 51. Outer shell; 511. Top wall; 512. Bottom wall; 513. Side wall; 514. First side wall; 515. Second side wall; 516. Third side wall; 517. Fourth side wall; 518. Clearance hole;

[0045] 61. First electrode terminal; 62. Second electrode terminal;

[0046] X, first direction; Y, second direction; Z, third direction. Detailed Implementation

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] In this application, "multiple" means two or more (including two).

[0054] 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.

[0055] 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.

[0056] A battery cell utilizes its casing to form a sealed space to house electrode components and electrolyte. During the manufacturing process, the casing typically includes a top cover, a middle steel plate, and a bottom steel plate. For prismatic battery cells, the middle steel plate is divided into two aligned U-shaped sections, resulting in a total of four parts in the casing. Welding these four parts requires first butting the two U-shaped sections together and then welding them. Next, the top cover and bottom steel plate are welded onto the middle steel plate. This process involves a relatively long welding path for the casing, leading to lower production efficiency.

[0057] In view of this, this application provides a battery cell in which the top wall, bottom wall and multiple side walls of the casing are formed by bending a single sheet of material and then welding them together. In this way, the bent and connected parts do not need to be welded during welding, thus shortening the welding path and improving welding efficiency, which in turn improves the production efficiency of the battery cell.

[0058] 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.

[0059] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0060] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0061] like Figure 1 As shown, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0062] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0063] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0064] Figure 2 This is a schematic diagram of the structure of a battery device 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.

[0065] like Figure 2 and Figure 3 As shown, the battery device 2 may include one or more battery cell assemblies 7 for providing voltage and capacity. The battery cell assembly 7 may include multiple battery cells 5, which are connected in series, parallel, or mixed connection via a busbar 71.

[0066] In some embodiments, the battery cell assembly 7 is typically formed by arranging multiple battery cells 5; as an example, the battery cell assembly 7 can be a battery module, which is formed by arranging and fixing multiple battery cells 5 into an independent module. As an example, a battery module can be formed by bundling multiple battery cells 5 together with cable ties.

[0067] In some embodiments, the battery device 2 may be a battery pack, which includes a housing 6 and one or more battery cell assemblies 7, the battery cell assemblies 7 being housed in the housing 6.

[0068] As an example, the battery cell assembly 7 can be a battery module, and the battery cell assembly 7 can be housed in the housing 6 by fixing the battery module in the housing 6.

[0069] As an example, the battery cell assembly 7 can also be housed in the housing 6 by directly fixing multiple battery cells 5 to the housing 6.

[0070] As an example, the housing 6 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 6 to house the battery cell assembly 7. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing 6 may be a top cover or a bottom plate.

[0071] As an example, the housing 6 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 6 forms an enclosed space to accommodate the battery cell assembly 7.

[0072] As an example, the box body 6 can be part of the chassis structure of the vehicle 1. For example, the top cover of the box body 6 can be at least part of the floor of the vehicle 1, or the frame of the box body 6 can be at least part of the crossbeams and longitudinal beams of the vehicle 1.

[0073] In some embodiments, battery device 2 refers to energy storage device, which includes a housing 6, with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0074] 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. Figure 4 This is a schematic diagram of the casing of a battery cell provided in some embodiments of this application.

[0075] like Figure 3 and Figure 4As shown, this application also provides a battery cell 5, including an electrode assembly and a housing 51. The housing 51 houses the electrode assembly. The housing 51 includes a top wall 511, a bottom wall 512, and a plurality of side walls 513. The top wall 511 and the bottom wall 512 are arranged opposite to each other along a first direction X. The two ends of each side wall 513 along the first direction X are respectively connected to the top wall 511 and the bottom wall 512. The top wall 511, the bottom wall 512, and the plurality of side walls 513 are formed by bending a piece of sheet metal and welded together at the joint.

[0076] In this embodiment of the application, when the battery cell 5 is in use, the top wall 511 is located above the bottom wall 512, and the side wall 513 is located between the top wall 511 and the bottom wall 512.

[0077] The number of sidewalls 513 in this embodiment can be four, five, or six. The shape of the outer shell 51 can be a cuboid, a pentagonal prism, or a hexagonal prism, etc.

[0078] The top wall 511, bottom wall 512, and multiple side walls 513 in this embodiment are formed by bending a single sheet of material. For example, the top wall 511, bottom wall 512, and multiple side walls 513 are formed by punching a single sheet of material, followed by bending. After bending, adjacent and separate wall sections are joined together to form a seam and then welded. The sheet material can be steel or other materials, such as aluminum.

[0079] In this embodiment, the outer casing 51 of the battery cell 5 is formed by bending a single sheet of material to create a top wall 511, a bottom wall 512, and multiple side walls 513. This reduces the total weld path and improves welding efficiency compared to welding the top and bottom sheets separately to the central frame, due to the presence of the bend. Furthermore, since it is formed from a single sheet of material, there is less variation in incoming materials compared to multiple components, resulting in better dimensional compatibility and improved welding yield.

[0080] In some embodiments, the welds formed at the joints are all located at the edges of the housing 51.

[0081] In this embodiment of the application, the edge of the outer shell 51 refers to the part where two adjacent walls of the outer shell 51 intersect.

[0082] Setting the weld seam at the edge of the outer shell 51 not only facilitates the cutting of the sheet metal, but also reduces the number of weld seams. A single weld seam may include part of the edge, one edge, or multiple edges, and is formed by continuous welding during the welding process.

[0083] In some embodiments, a portion of the weld formed at the joint is located on the side wall 513 or the bottom wall 512.

[0084] In this embodiment of the application, "the weld is located on the side wall 513 or the bottom wall 512" means that the weld is located at a non-edge location of the side wall 513 or the bottom wall 512.

[0085] By placing some welds on the side wall 513 or the bottom wall 512, weld cracking caused by electrode assembly expansion fatigue can be reduced.

[0086] Please continue reading. Figure 4 In some embodiments, the plurality of sidewalls 513 include a first sidewall 514 and a second sidewall 515 disposed opposite to each other along the second direction Y, and a third sidewall 516 and a fourth sidewall 517 disposed opposite to each other along the third direction Z. The first direction X, the second direction Y and the third direction Z intersect each other, and the area of ​​the first sidewall 514 or the second sidewall 515 is smaller than the area of ​​the third sidewall 516 or the fourth sidewall 517.

[0087] In this embodiment of the application, the area of ​​the first sidewall 514 or the second sidewall 515 is smaller than the area of ​​the third sidewall 516 or the fourth sidewall 517, that is, the area of ​​either the first sidewall 514 or the second sidewall 515 is smaller than the area of ​​either the third sidewall 516 or the fourth sidewall 517.

[0088] Optionally, the first direction X, the second direction Y, and the third direction Z are all perpendicular to each other.

[0089] The multiple sidewalls 513 are configured to include a first sidewall 514, a second sidewall 515, a third sidewall 516, and a fourth sidewall 517. The outer shell 51 of this type of battery cell 5 has a relatively regular shape, which is convenient for cutting sheet metal, as well as for welding, and the welding path is relatively short.

[0090] In some embodiments, the battery cell 5 further includes a first electrode terminal 61 and a second electrode terminal 62; both the first electrode terminal 61 and the second electrode terminal 62 are disposed on the top wall 511 or the bottom wall 512, or the first electrode terminal 61 is disposed on the first side wall 514 and the second electrode terminal 62 is disposed on the second side wall 515.

[0091] In this embodiment of the application, the first electrode terminal 61 is a positive electrode terminal and the second electrode terminal 62 is a negative electrode terminal; or, the first electrode terminal 61 is a negative electrode terminal and the second electrode terminal 62 is a positive electrode terminal.

[0092] By placing the first electrode terminal 61 and the second electrode terminal 62 at locations other than the third sidewall 516 and the fourth sidewall 517, it is easier to connect them to the internal electrode assembly.

[0093] Figure 5 This is a schematic diagram of the casing of a battery cell provided in some embodiments of this application in an unbent state. Figure 6This is a schematic diagram illustrating another structural configuration of the battery cell casing in an unbent state, as provided in some embodiments of this application. Figure 7 This is a schematic diagram of another structure of the casing of a battery cell provided in some embodiments of this application in an unbent state.

[0094] Please see Figure 5 , Figure 6 and Figure 7 In some embodiments, the third sidewall 516, the top wall 511, the fourth sidewall 517, and the bottom wall 512 are bent and connected in sequence, or the third sidewall 516, the bottom wall 512, the fourth sidewall 517, and the top wall 511 are bent and connected in sequence; the first sidewall 514 and the second sidewall 515 are respectively bent and connected to the two ends of the third sidewall 516 opposite to each other along the second direction Y, or the first sidewall 514 and the second sidewall 515 are respectively bent and connected to the two ends of the fourth sidewall 517 opposite to each other along the second direction Y.

[0095] In this embodiment of the application, the first electrode terminal 61 and the second electrode terminal 62 can be simultaneously disposed on the top wall 511, such as... Figure 5 and Figure 7 As shown; or, the first electrode terminal 61 is disposed on the first sidewall 514, and the second electrode terminal 62 is disposed on the second sidewall 515, as shown. Figure 6 As shown; or other circumstances.

[0096] For example, during assembly, the first electrode terminal 61 and the second electrode terminal 62 are first riveted to the two clearance holes 518 by riveting with components such as insulating pads; after the electrode assembly is welded to the two adapter pieces, the two adapter pieces are then welded to the first electrode terminal 61 and the second electrode terminal 62 respectively; after welding is completed, the outer shell 51 is bent 90° according to the dotted line in the figure; the welding at the joint is completed by laser welding.

[0097] In this way, the weld of the outer shell 51 is located at the edge, which not only facilitates the cutting of the sheet metal, but also reduces the number of welds formed.

[0098] In other embodiments, the third sidewall 516, the first sidewall 514, the fourth sidewall 517, and the second sidewall 515 are bent and connected in sequence; the top wall 511 and the bottom wall 512 are respectively bent and connected to the two ends of the third sidewall 516 opposite to each other along the first direction X, or the top wall 511 and the bottom wall 512 are respectively bent and connected to the two ends of the fourth sidewall 517 opposite to each other along the first direction X, or the top wall 511 is bent and connected to one of the third sidewall 516 and the fourth sidewall 517, and the bottom wall 512 is bent and connected to the other of the third sidewall 516 and the fourth sidewall 517.

[0099] Figure 8This is another structural schematic diagram of the casing of a battery cell provided in some embodiments of this application in an unbent state.

[0100] Please see Figure 8 In some embodiments, the third sidewall 516, the top wall 511, the fourth sidewall 517, and the bottom wall 512 are bent and connected in sequence, or the third sidewall 516, the bottom wall 512, the fourth sidewall 517, and the top wall 511 are bent and connected in sequence; the first sidewall 514 is bent and connected to one of the third sidewall 516 and the fourth sidewall 517, and the second sidewall 515 is bent and connected to the other of the third sidewall 516 and the fourth sidewall 517.

[0101] In this embodiment of the application, the first electrode terminal 61 and the second electrode terminal 62 may be simultaneously disposed on the top wall 511; or, the first electrode terminal 61 may be disposed on the first side wall 514 and the second electrode terminal 62 may be disposed on the second side wall 515; or other situations may exist.

[0102] In this way, the weld of the outer shell 51 is located at the edge, which makes it easy to cut and reduces the number of welds.

[0103] Figure 9 This is another structural schematic diagram of the casing of a battery cell provided in some embodiments of this application in an unbent state.

[0104] Please see Figure 9 In some embodiments, a portion of the third sidewall 516, top wall 511, fourth sidewall 517, bottom wall 512 and another portion of the third sidewall 516 are bent and connected in sequence, and the first sidewall 514 and the second sidewall 515 are bent and connected to the opposite ends of the fourth sidewall 517 along the second direction Y.

[0105] In this embodiment of the application, the first electrode terminal 61 and the second electrode terminal 62 may be simultaneously disposed on the top wall 511; or, the first electrode terminal 61 may be disposed on the first side wall 514 and the second electrode terminal 62 may be disposed on the second side wall 515; or other situations may exist.

[0106] The areas of the two third sidewalls 516 in this embodiment can be equal or unequal.

[0107] Optionally, the area of ​​the third side wall 516 that is bent and connected to the top wall 511 is larger than the area of ​​the third side wall 516 that is bent and connected to the bottom wall 512, that is, the weld is located at the lower part of the third side wall 516.

[0108] Placing the weld on the third sidewall 516 can mitigate the problem of weld cracking caused by the expansion fatigue of the electrode assembly.

[0109] In other embodiments, a portion of the third sidewall 516, the first sidewall 514, the fourth sidewall 517, the second sidewall 515, and another portion of the third sidewall 516 are bent and connected in sequence, and the top wall 511 and the bottom wall 512 are bent and connected to the two ends of the fourth sidewall 517 opposite to each other along the first direction X.

[0110] Figure 10 This is another structural schematic diagram of the casing of a battery cell provided in some embodiments of this application in an unbent state.

[0111] Please see Figure 10 In some embodiments, the third sidewall 516, the top wall 511, the fourth sidewall 517, and the bottom wall 512 are bent and connected in sequence, or the third sidewall 516, the bottom wall 512, the fourth sidewall 517, and the top wall 511 are bent and connected in sequence; a portion of the first sidewall 514 is bent and connected to the third sidewall 516, another portion of the first sidewall 514 is bent and connected to the fourth sidewall 517, a portion of the second sidewall 515 is bent and connected to the third sidewall 516, and another portion of the second sidewall 515 is bent and connected to the fourth sidewall 517.

[0112] The first electrode terminal 61 and the second electrode terminal 62 in this embodiment can be simultaneously disposed on the top wall 511; or other situations may apply.

[0113] The areas of the first sidewalls 514 of the two parts in this embodiment can be equal or unequal; the areas of the second sidewalls 515 of the two parts can be equal or unequal.

[0114] By placing the weld on the first sidewall 514 and the second sidewall 515, the problem of weld cracking caused by the expansion fatigue of the electrode assembly can be mitigated.

[0115] In some embodiments, the battery cell 5 is a prismatic battery cell.

[0116] The outer shell 51 of the square battery cell has a relatively regular shape, which makes it easy to cut the sheet metal and also easy to weld, and the welding path is shorter.

[0117] In some embodiments, the wall thickness of the outer shell 51 is h, where h satisfies: 0.2mm≤h≤0.9mm.

[0118] Optionally, the value of h can be 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm or 0.9mm.

[0119] Limiting the wall thickness of the outer casing 51 to greater than or equal to 0.2 mm ensures that the structural strength of the outer casing 51 meets the usage requirements; limiting the wall thickness of the outer casing 51 to less than or equal to 0.9 mm can improve the volumetric energy density and gravimetric energy density of the battery cell under the same external dimensions.

[0120] In some embodiments, h satisfies: 0.3mm ≤ h ≤ 0.5mm.

[0121] Optionally, the value of h can be 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.5mm.

[0122] Limiting the wall thickness of the outer casing 51 to greater than or equal to 0.3 mm can further improve the structural strength of the outer casing 51; limiting the wall thickness of the outer casing 51 to less than or equal to 0.5 mm can further improve the volumetric energy density and gravimetric energy density of the battery cell 5 under the same external dimensions.

[0123] This application also provides a battery device 2, which includes the battery cell 5 described above.

[0124] This application embodiment also provides an electrical device, including the battery device 2 described above, which is used to provide electrical energy.

[0125] Please see Figure 3 and Figure 4 This application provides a battery cell 5, including an electrode assembly and a housing 51. The housing 51 houses the electrode assembly and includes a top wall 511, a bottom wall 512, and multiple side walls 513. The top wall 511 and the bottom wall 512 are arranged opposite each other along a first direction X. The two opposite ends of each side wall 513 along the first direction X are respectively connected to the top wall 511 and the bottom wall 512. The top wall 511, the bottom wall 512, and the multiple side walls 513 are formed by bending a single sheet of material and welded together at the joints. The multiple side walls 513 include a first side wall 514 and a second side wall 515 arranged opposite each other along a second direction Y, and a third side wall 516 and a fourth side wall 517 arranged opposite each other along a third direction Z. The first direction X, the second direction Y, and the third direction Z intersect each other in pairs. The area of ​​the first side wall 514 or the second side wall 515 is smaller than the area of ​​the third side wall 516 or the fourth side wall 517. The battery cell 5 also includes a first electrode terminal 61 and a second electrode terminal 62; the first electrode terminal 61 and the second electrode terminal 62 are both disposed on the top wall 511 or the bottom wall 512, or the first electrode terminal 61 is disposed on the first side wall 514 and the second electrode terminal 62 is disposed on the second side wall 515.

[0126] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0127] 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 that accommodates the electrode assembly includes a top wall, a bottom wall, and multiple side walls. The top wall and the bottom wall are disposed opposite each other along a first direction, and the two ends of each side wall that are opposite to each other along the first direction are respectively connected to the top wall and the bottom wall. The top wall, the bottom wall, and the multiple side walls are formed by bending a single sheet of material and welded together at the joints.

2. The battery cell according to claim 1, characterized in that, The welds formed at the joints are all located at the edges of the outer shell.

3. The battery cell according to claim 1, characterized in that, The portion of the weld formed at the joint is located on the side wall or the bottom wall.

4. The battery cell according to claim 1, characterized in that, The multiple sidewalls include a first sidewall and a second sidewall disposed opposite to each other along a second direction, and a third sidewall and a fourth sidewall disposed opposite to each other along a third direction. The first direction, the second direction and the third direction intersect each other, and the area of ​​the first sidewall or the second sidewall is smaller than the area of ​​the third sidewall or the fourth sidewall.

5. The battery cell according to claim 4, characterized in that, The battery cell also includes a first electrode terminal and a second electrode terminal; Both the first electrode terminal and the second electrode terminal are disposed on the top wall or the bottom wall, or the first electrode terminal is disposed on the first side wall and the second electrode terminal is disposed on the second side wall.

6. The battery cell according to claim 4, characterized in that, The third sidewall, the top wall, the fourth sidewall, and the bottom wall are bent and connected in sequence, or the third sidewall, the bottom wall, the fourth sidewall, and the top wall are bent and connected in sequence. The first sidewall and the second sidewall are respectively bent and connected to the two ends of the third sidewall that are opposite to each other along the second direction, or the first sidewall and the second sidewall are respectively bent and connected to the two ends of the fourth sidewall that are opposite to each other along the second direction.

7. The battery cell according to claim 4, characterized in that, The third sidewall, the top wall, the fourth sidewall, and the bottom wall are bent and connected in sequence, or the third sidewall, the bottom wall, the fourth sidewall, and the top wall are bent and connected in sequence. The first sidewall is bent and connected to one of the third sidewall and the fourth sidewall, and the second sidewall is bent and connected to the other of the third sidewall and the fourth sidewall.

8. The battery cell according to claim 4, characterized in that, A portion of the third sidewall, the top wall, the fourth sidewall, the bottom wall, and another portion of the third sidewall are sequentially bent and connected, and the first sidewall and the second sidewall are respectively bent and connected to opposite ends of the fourth sidewall along the second direction.

9. The battery cell according to claim 4, characterized in that, The third sidewall, the top wall, the fourth sidewall, and the bottom wall are bent and connected in sequence, or the third sidewall, the bottom wall, the fourth sidewall, and the top wall are bent and connected in sequence. A portion of the first sidewall is bent and connected to the third sidewall, another portion of the first sidewall is bent and connected to the fourth sidewall, a portion of the second sidewall is bent and connected to the third sidewall, and another portion of the second sidewall is bent and connected to the fourth sidewall.

10. The battery cell according to claim 1, characterized in that, The battery cell is a prismatic battery cell.

11. The battery cell according to any one of claims 1-10, characterized in that, The wall thickness of the outer shell is h, and h satisfies: 0.2mm≤h≤0.9mm.

12. The battery cell according to claim 11, characterized in that, The h satisfies: 0.3mm≤h≤0.5mm.

13. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-12.

14. An electrical appliance, characterized in that, Includes the battery device as described in claim 13, the battery device being used to provide electrical energy.

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