Battery cell, battery device and electric device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device. The battery cell includes a housing, an electrode assembly, and an electrode terminal. A containing cavity is formed in the shell. The shell comprises a first wall, a second wall and a third wall. In the first direction, the first wall and the third wall are oppositely arranged, the second wall is located between the first wall and the third wall, and the second wall is connected with the first wall and the third wall. The electrode assembly is arranged in the containing cavity. The electrode terminals are arranged on the shell and electrically connected with the electrode assembly, and the electrode terminals are located on other wall portions except the first wall, the second wall and the third wall of the shell. Wherein the face, facing the interior of the containing cavity, of the first wall is a first face, the face, facing the interior of the containing cavity, of the second wall is a second face, the first face and the second face are directly connected, a first preset included angle is formed between the first face and the second face, and the first preset included angle is not smaller than 85 degrees and not larger than 95 degrees. According to the technical scheme provided by the invention, the reliability of the battery device can be effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and more specifically, to a battery cell, a battery device, and an electrical device. Background Art

[0002] Energy conservation and emission reduction are the keys to the sustainable development of the automotive industry. Electric vehicles have become an important part of the sustainable development of the automotive industry due to their advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor related to their development.

[0003] In the development of battery technology, how to improve the reliability of battery devices is a technical problem that urgently needs to be solved in battery technology. Summary of the Utility Model

[0004] The present application provides a battery cell, a battery device, and an electrical device. The technical solution provided by the present application can effectively improve the reliability of the battery device.

[0005] In a first aspect, some embodiments of the present application provide a battery cell. The battery cell includes a housing, an electrode assembly, and electrode terminals. An accommodation cavity is formed inside the housing. The housing includes a first wall, a second wall, and a third wall. Along a first direction, the first wall and the third wall are oppositely arranged. The second wall is located between the first wall and the third wall, and the second wall connects the first wall and the third wall. The electrode assembly is disposed in the accommodation cavity. The electrode assembly is a laminated structure, and the first direction is the lamination direction of the electrode assembly; or, the electrode assembly is a wound structure. The electrode assembly includes a planar region in the middle and corner regions on both sides, and the first direction is the lamination direction of the electrode assembly in the planar region. The electrode terminals are disposed on the housing and are electrically connected to the electrode assembly. The electrode terminals are located on other wall portions outside the first wall, the second wall, and the third wall of the housing. Wherein, the surface of the first wall facing the inside of the accommodation cavity is the first surface, the surface of the second wall facing the inside of the accommodation cavity is the second surface, the first surface and the second surface are directly connected, and the connection region forms a first preset angle. The first preset angle is not less than 85° and not greater than 95°.

[0006] In the related art, as the number of charge and discharge cycles of the battery cell increases, the battery cell expands internally, and the expansion force of the battery cell in the first direction is relatively large. That is, the electrode assembly is more likely to expand in the direction of the first wall and the third wall. In the above solution, by setting the first surface of the first wall to be directly connected to the second surface of the second wall, and making the first preset angle between the first surface and the second surface a right angle or an angle approaching a right angle, it is possible to improve the interference of the internal fillet between the first wall and the second wall on the electrode assembly, resulting in damage to the structure of the electrode assembly and reducing the risk of the reliability of the battery cell. Therefore, the reliability of the battery device can be effectively improved.

[0007] According to some embodiments of the present application, the electrode assembly includes a main body and an insulating film. The insulating film covers at least a part of the main body, and the insulating film is in direct contact with the second wall.

[0008] In the above solution, by setting the first surface of the first wall to be directly connected to the second surface of the second wall, and making the first preset angle between the first surface and the second surface be a right angle or an angle approaching a right angle, there is no internal fillet between the first surface and the second surface. Thus, the risk of interference between the electrode assembly and the junction part of the first surface and the second surface can be effectively reduced. Furthermore, the bottom support plate in the related art can be eliminated, and the insulating film can be directly in contact with the second surface, thereby improving the space utilization rate of the electrode assembly to achieve the effect of increasing the volume energy density of the battery cell, and further facilitating the improvement of the volume energy density of the battery device.

[0009] According to some embodiments of the present application, the first wall and the second wall are formed by welding.

[0010] In the above solution, two independent structures of the first wall and the second wall are welded into one body, so that there is no internal fillet between the first wall and the second wall. On the one hand, it can improve the problem of interference of the junction part between the first wall and the second wall with the electrode assembly, and reduce the problem that the structure of the electrode assembly is damaged and affects the reliability of the battery. On the other hand, the bottom support plate in the related art can be eliminated, thereby improving the space utilization rate of the electrode assembly to achieve the effect of increasing the volume energy density of the battery cell, and further facilitating the improvement of the volume energy density of the battery device. On the other hand, the welding process is simple, the connection is reliable, and the manufacturing efficiency is high, which is conducive to the improvement of the manufacturing efficiency of the battery device.

[0011] According to some embodiments of the present application, the surface of the third wall facing the accommodation cavity is the third surface. The third surface and the second surface are directly connected and the connection area forms a second preset angle. The second preset angle is not less than 85° and not more than 95°.

[0012] In the above solution, by setting the third surface of the third wall to be directly connected to the second surface of the second wall, and making the second preset angle between the third surface and the second surface be a right angle or an angle approaching a right angle, the interference of the internal fillet between the third wall and the second wall with the electrode assembly, which may cause damage to the structure of the electrode assembly and reduce the reliability of the battery cell, can be improved. Thus, the reliability of the battery device can be effectively improved.

[0013] According to some embodiments of the present application, the third wall and the second wall are formed by welding.

[0014] In the above solution, the third wall and the second wall, which are two independent structures, are welded into one body, so that there is no internal fillet between the third wall and the second wall. On the one hand, it can improve the problem of interference of the junction part between the third wall and the second wall with the electrode assembly, and reduce the problem that the structure of the electrode assembly is damaged and the reliability of the battery is affected. On the other hand, it can cancel the bottom plate in the related technology, thereby improving the space utilization rate of the electrode assembly to achieve the effect of increasing the volume energy density of the battery cell, and further facilitating the improvement of the volume energy density of the battery device. On the other hand, the welding process is simple, the connection is reliable and the manufacturing efficiency is high, which is conducive to the improvement of the manufacturing efficiency of the battery device.

[0015] According to some embodiments of the present application, the housing further includes a fourth wall and a fifth wall. Along the second direction, the fourth wall and the fifth wall are opposite to each other, and the first direction and the second direction are perpendicular to each other. The surface of the fourth wall facing the accommodation cavity is the fourth surface, the fourth surface and the second surface are directly connected and the connection area forms a third preset angle, the third preset angle is not less than 85° and not more than 95°; and / or the surface of the fifth wall facing the accommodation cavity is the fifth surface, the fifth surface and the second surface are directly connected and the connection area forms a fourth preset angle, the fourth preset angle is not less than 85° and not more than 95°.

[0016] In the above solution, by setting the fourth surface of the fourth wall to be directly connected to the second surface of the second wall, and making the third preset angle between the fourth surface and the second surface a right angle or an angle approaching a right angle, it can improve the interference of the internal fillet between the fourth wall and the second wall with the electrode assembly, resulting in damage to the structure of the electrode assembly and reducing the reliability of the battery cell. Therefore, the reliability of the battery device can be effectively improved; at the same time, by setting the fifth surface of the fifth wall to be directly connected to the second surface of the second wall, and making the fourth preset angle between the fifth surface and the second surface a right angle or an angle approaching a right angle, it can improve the interference of the internal fillet between the fifth wall and the second wall with the electrode assembly, resulting in damage to the structure of the electrode assembly and reducing the reliability of the battery cell. Therefore, the reliability of the battery device can be effectively improved.

[0017] According to some embodiments of the present application, the fourth wall and the second wall are welded and formed; and / or the fifth wall and the second wall are welded and formed.

[0018] In the above solution, the fourth wall and the second wall, which are two independent structures, are welded into one body, and the fifth wall and the second wall, which are two independent structures, are welded together by wire, so that there is no internal fillet between the fourth wall and the second wall and between the fifth wall and the second wall. On the one hand, it can improve the interference problem of the electrode assembly at the junction of the fourth wall and the second wall and at the junction of the fifth wall and the second wall, and reduce the problem that the structure of the electrode assembly is damaged, affecting the reliability of the battery; on the other hand, it can cancel the bottom support plate in the related technology, thereby improving the space utilization rate of the electrode assembly, achieving the effect of improving the volume energy density of the battery cell, and further facilitating the improvement of the volume energy density of the battery device; on the third hand, the welding process is simple, the connection is reliable and the manufacturing efficiency is high, which is conducive to the improvement of the manufacturing efficiency of the battery device.

[0019] According to some embodiments of the present application, the outer shell includes a housing, the housing is an integral structure, the housing includes a first wall, a third wall, a fourth wall and a fifth wall, and along the thickness direction of the second wall, one end of the housing has a first opening, and the second wall closes the first opening.

[0020] In the above solution, the integral housing includes a first wall, a third wall, a fourth wall and a fifth wall. By connecting the second wall to the first wall, the third wall, the fourth wall and the fifth wall respectively, on the one hand, it can close the first opening of the housing to support the electrode assembly or provide a closed space for the electrode assembly. On the other hand, it can make there be no internal fillet at the junction of the housing and the second wall, so as to reduce the interference of the housing on the electrode assembly, thereby canceling the bottom support plate in the related technology to balance the reliability and energy density improvement of the battery cell; on the third hand, during the manufacturing process, the assembly difficulty of the integral housing and the first wall is small, so the manufacturing efficiency of the battery cell is high, and further the manufacturing efficiency of the battery device is high.

[0021] According to some embodiments of the present application, the outer shell further includes a sixth wall. Along the thickness direction of the second wall, the other end of the housing has a second opening, and the sixth wall closes the second opening.

[0022] In the above solution, the outer shell includes a housing, a sixth wall and a second wall which are separate structures, and the three are connected to each other respectively. On the one hand, it improves the problem that the interference of the junction of the housing and the second wall on the electrode assembly causes damage to the structure of the electrode assembly and affects the reliability of the battery cell. On the other hand, during the manufacturing and assembly process of the battery cell, it can reduce the forming difficulty of the outer shell and reduce the manufacturing cost of the battery cell.

[0023] According to some embodiments of the present application, along the circumferential direction of the outer shell, the opposite ends of the fourth wall are bent to the first wall and the third wall respectively. Along the circumferential direction of the outer shell, the fifth wall includes a first part and a second part. The first part is bent to the first wall, and the second part is bent to the third wall, and the first part and the second part are welded and formed.

[0024] In the above solution, a shell-like structural member can be formed by bending a plate-like structure, and the first part and the second part can be connected to each other by welding to form a housing. That is, the manufacturing of the housing can be completed through a bending process and a welding process, so that the manufacturing process of the housing is simple, the process cycle is fast, which is beneficial to improving the manufacturing efficiency of battery cells, and further beneficial to improving the manufacturing efficiency of battery devices.

[0025] According to some embodiments of the present application, the housing further includes a sixth wall. Along the circumferential direction of the outer shell, the first wall, the third wall, the fourth wall, and the fifth wall surround the edge of the sixth wall. Along the thickness direction of the second wall, the sixth wall and the second wall are opposite to each other.

[0026] In the above solution, the housing of an integral structure includes a sixth wall and the first wall, the third wall, the fourth wall, and the fifth wall surrounding the edge of the sixth wall, making the housing a cylindrical structure with one end closed and the other end open. On the one hand, it is beneficial to the assembly of the electrode assembly, reducing the assembly process of battery cells and being beneficial to improving the manufacturing efficiency of battery devices; on the other hand, it reduces the connection interfaces on the surface of the outer shell, which is beneficial to improving the airtightness of battery cells, the reliability of battery cells, and further beneficial to the reliability of battery devices.

[0027] According to some embodiments of the present application, the electrode terminal is disposed on the sixth wall.

[0028] In the above solution, by disposing the electrode terminal on the sixth end to connect with the tab lead-out end of the electrode assembly, the second wall can contact the other end of the electrode terminal without being interfered by the intersection of the second wall and the housing, so that the bottom support plate in the related art can be eliminated, which is beneficial to improving the volume energy density of battery cells and further beneficial to improving the volume energy density of battery devices.

[0029] According to some embodiments of the present application, the first wall, the third wall, the fourth wall, and the fifth wall are of a split structure. The opposite ends of the fourth wall in the second direction are respectively welded to the first wall and the third wall, and the opposite ends of the fifth wall in the second direction are respectively welded to the first wall and the third wall.

[0030] In the above solution, the outer shell is formed by welding multiple split structures, which can effectively reduce the interference of the connection interfaces between the inner walls of the outer shell on the electrode assembly, beneficial to improving the space utilization rate of the battery assembly, thus beneficial to improving the volume energy density of battery cells and further beneficial to improving the volume energy density of battery devices.

[0031] According to some embodiments of the present application, along the thickness direction of the second wall, the electrode terminal is disposed on the wall of the outer shell opposite to the second wall.

[0032] In the above scheme, the electrode terminal is arranged on the side of the shell away from the second wall, that is, the electrode assembly is a single-sided electrode ear, which can reduce the space occupied by the electrode terminal and the electrode assembly in the thickness direction of the second wall, which is beneficial to the improvement of the volume energy density of the battery cell and the volume energy density of the battery device.

[0033] According to some embodiments of the present application, the electrode terminal is disposed on a wall portion of the housing along the second direction, and the first direction, the second direction, and the thickness direction of the second wall are perpendicular to each other.

[0034] In the above scheme, by arranging the electrode terminal on the wall portion of the shell along the second direction, the space occupied by the electrode terminal and the electrode assembly in the thickness direction of the second wall and the first direction can be reduced, which is beneficial to the improvement of the volume energy density of the battery cell and the volume energy density of the battery device. In the related technology, especially in the blade battery, the surface of the shell along the second direction is the side surface (small surface). By arranging the electrode terminal on the side surface, the high volume energy density of the blade battery can be fully utilized to further improve the volume energy density of the battery device.

[0035] According to some embodiments of the present application, the electrode terminal includes a first electrode terminal and a second electrode terminal with opposite polarities, the first electrode terminal is arranged on a wall portion of the shell along the second direction, and the second electrode terminal is arranged on another wall portion of the shell along the second direction.

[0036] In the above scheme, by respectively arranging the first electrode terminal and the second electrode terminal with opposite polarities on two wall portions of the outer shell opposite to each other along the second direction, the negative electrode charge state can be distributed more evenly, thereby reducing the risk of lithium plating, effectively reducing the risk of internal short circuit and heat generation of the battery cell, improving the reliability of the battery cell, and facilitating the improvement of the reliability of the battery device.

[0037] According to some embodiments of the present application, the shell is made of steel, and the thickness of the shell is not less than 0.075 mm and not more than 0.3 mm.

[0038] In the above scheme, the material of the shell is steel with high structural strength, so that the wall thickness of the shell can be greatly reduced on the basis of the overall structural strength of the battery cell. For example, the thickness of the shell is limited to not less than 0.075mm and not more than 0.3mm, thereby reducing the proportion of the shell in the battery cell, thereby making the battery cell have a higher volume energy density, which is beneficial to the improvement of the volume energy density of the battery device.

[0039] According to some embodiments of the present application, the first wall and the second wall are connected by a first connecting portion, the first surface is in contact with the outer peripheral surface of the second wall, and along the first direction, the first connecting portion is located between the first surface and the outer peripheral surface of the second wall, and a portion of the first connecting portion is located on the side of the second wall that is away from the accommodating cavity.

[0040] In the above scheme, the first surface is connected to the second wall through the first connecting portion and the first surface is in contact with the outer peripheral surface of the second wall. The portion that cooperates with the first connecting portion is located on the side of the second wall that is away from the accommodating cavity. This can reduce the difficulty of connecting the first wall and the second wall. For example, welding the junction of the first wall and the second wall from the side of the first wall that is away from the accommodating cavity can effectively improve the connection efficiency of the first wall and the second wall, thereby improving the manufacturing efficiency of the battery cell.

[0041] According to some embodiments of the present application, the first connection portion includes a weld mark formed between the first wall and the second wall.

[0042] According to some embodiments of the present application, the first wall and the second wall are connected by a first connecting portion, and a convex portion is formed on the side of the second wall facing the accommodating cavity along the thickness direction of the second wall, and the outer peripheral surface of the convex portion contacts the first surface, and the first connecting portion is located between the end surface of the first wall and the second wall along the thickness direction of the second wall.

[0043] In the above scheme, by providing a protrusion on the side of the second wall facing the accommodating cavity, the second wall and the first wall can be positioned relative to each other, which can reduce the risk of misalignment between the second wall and the first wall, thereby improving the connection reliability between the first wall and the second wall, which is beneficial to improving the reliability of the battery cell structure.

[0044] According to some embodiments of the present application, the first connection portion includes a weld mark formed between the first wall and the second wall.

[0045] In a second aspect, some embodiments of the present application further provide a battery device, comprising the battery cell provided in the first aspect.

[0046] In a third aspect, some embodiments of the present application further provide an electrical device, comprising the battery cell provided in the first aspect and / or the battery device provided in the second aspect, wherein the battery cell is used to provide electrical energy.

[0047] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0049] Figure 1 Schematic structural diagram of a vehicle in some embodiments of the present application;

[0050] Figure 2 Exploded perspective view of a battery device in some embodiments of the present application;

[0051] Figure 3 Exploded perspective view of a battery cell in some embodiments of the present application;

[0052] Figure 4 Schematic internal structure diagram of a first wall, a second wall, and an electrode assembly in some embodiments of the present application;

[0053] Figure 5 Schematic structural diagram of a fourth wall, a fifth wall, and a second wall in some embodiments of the present application;

[0054] Figure 6 Exploded perspective view of a housing in some embodiments of the present application;

[0055] Figure 7 Exploded perspective view of a housing in some other embodiments of the present application;

[0056] Figure 8 Schematic diagram of a battery cell in some other embodiments of the present application;

[0057] Figure 9 is Figure 4 an enlarged view of part A in

[0058] Figure 10 Schematic structural diagram of a first wall, a second wall, and a third wall in some other embodiments of the present application;

[0059] Figure 11 is Figure 10 an enlarged view of part B in

[0060] Icons: 1000 - vehicle; 100 - battery device; 200 - controller; 300 - motor; 10 - battery cell; 20 - housing; 21 - first housing part; 22 - second housing part; 30 - outer shell; 30a - housing body; 30b - first opening; 30c - second opening; 31 - first wall; 310 - first surface; 32 - second wall; 320 - second surface; 321 - convex part; 322 - body; 33 - third wall; 330 - third surface; 34 - fourth wall; 340 - fourth surface; 35 - fifth wall; 350 - fifth surface; 351 - first part; 352 - second part; 36 - sixth wall; 11 - electrode assembly; 110 - main body; 111 - insulating film; 12 - electrode terminal; 12a - first electrode terminal; 12b - second electrode terminal; 12c - adapter; 13 - first connection part; x - first direction; y - second direction; z - thickness direction of the second wall. Detailed implementation manners

[0061] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0062] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "comprising" and "having" and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of the present application or the above drawings are used to distinguish different objects and not to describe a specific order or primary-secondary relationship.

[0063] Referring to "embodiments" in the present application means that specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0064] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "joined", and "attached" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0065] The term "and / or" in the present application is merely an association relationship describing the associated objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and back associated objects.

[0066] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width, etc. of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width, etc. of the integrated device, are only illustrative and should not constitute any limitation to the present application.

[0067] The term "a plurality of" as used in the present application refers to two or more (including two).

[0068] In the embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging to continue using.

[0069] The battery cell can be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc., and the embodiments of the present application do not limit this.

[0070] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can prevent the short circuit between the positive and negative electrodes and at the same time allow the active ions to pass through.

[0071] In some embodiments, the positive electrode can be a positive electrode sheet, and the positive electrode sheet can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0072] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative electrode current collector.

[0073] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0074] In some embodiments, the separator is a separator membrane. The types of separator membranes can be various, and any well-known porous structure separator membrane with good chemical stability and mechanical stability can be selected.

[0075] In some embodiments, the battery cell further includes an electrolyte that functions to conduct ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Among them, the liquid electrolyte includes electrolyte salts and solvents.

[0076] In some embodiments, the electrode assembly is in a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0077] In some embodiments, the electrode assembly is in a stacked structure.

[0078] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be respectively provided, and the multiple positive electrode sheets and the multiple negative electrode sheets are alternately stacked.

[0079] As an example, multiple positive electrode sheets can be provided, and the negative electrode sheet is folded to form multiple stacked folding segments, and a positive electrode sheet is clamped between adjacent folding segments.

[0080] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form multiple stacked folding segments.

[0081] As an example, multiple separators can be provided and are respectively disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0082] As an example, the separator can be continuously provided and is disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0083] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or multi-prismatic, etc.

[0084] In some embodiments, the electrode assembly is provided with tabs, and the tabs can conduct current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0085] In some embodiments, the battery cell can include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc.

[0086] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell or a battery cell of other shapes. The prismatic battery cell includes, but is not limited to, a square shell battery cell, a blade-shaped battery cell, a multi-prismatic battery, and the multi-prismatic battery is, for example, a hexagonal prism battery, etc.

[0087] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include a plurality of battery cells, and the plurality of battery cells are connected in series, parallel or in a hybrid connection through a busbar component.

[0088] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly can be a battery module, and the battery module is formed by arranging and fixing a plurality of battery cells into an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with cable ties.

[0089] In some embodiments, the battery device can be a battery pack, and the battery pack includes a box body and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the box body.

[0090] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be accommodated in the box body by fixing the battery module in the box body.

[0091] As an example, the battery cell assembly can also be accommodated in the box body by directly fixing a plurality of battery cells to the box body.

[0092] As an example, the box body may include a first box body and a second box body. The first box body and the second box body are snapped together so that a closed space is formed inside the box body to accommodate the battery cell assembly. The "closed" here means covering or closing, which can be sealed or non-sealed. The first box body can be a top cover or a bottom plate.

[0093] As an example, the box body 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 a closed space is formed inside the box body to accommodate the battery cell assembly.

[0094] As an example, the box body can be a part of the chassis structure of a vehicle. For example, the top cover of the box body can become at least a part of the floor of the vehicle, or the frame of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0095] In some embodiments, the battery device may refer to an energy storage device, which includes a box body, and at least one side of the box body is provided with a door. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0096] Exemplarily, the battery device includes a beam assembly and a battery cell assembly. The beam assembly may include a mounting beam and an installation beam arranged mutually. The installation beam is used for installing and fixing the battery cell assembly, and the mounting beam is used for mounting the battery on the main body of the electrical device, so that the battery supplies power to the main body of the electrical device. Among them, in some embodiments, the beam assembly may be a partial structural member of the box body.

[0097] The battery device has outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and small self-discharge coefficient, and is an important part of the development of new energy today. The development of battery technology needs to consider various design factors at the same time, such as performance parameters such as cycle life, discharge capacity, charge and discharge rate, etc. In addition, the energy density and reliability of the battery device also need to be considered.

[0098] In battery technology, a battery cell includes a housing, an electrode assembly, and electrode terminals. The electrode assembly is disposed inside the housing, and the electrode terminals are disposed on the wall of the housing and electrically connected to the electrode assembly. In the related art, the housing generally includes a shell and an end cap. The shell has an opening, the electrode assembly is placed into the shell through the opening, and the end cap closes the opening and is connected to the shell so that the electrode assembly is located in a closed space. The electrode terminals are disposed on the end cap and electrically connected to the electrode assembly. Generally, the shell is an integral structure and is usually formed by a stamping process. There is an inner fillet at the intersection of two adjacent walls of the shell, and the inner fillet will interfere with the electrode assembly, resulting in damage to the structure of the electrode assembly. Particularly, as the number of charge and discharge cycles of the battery cell increases, the inside of the battery cell expands, and the large surface of the housing is greatly affected by the expansion force. The influence of the inner fillet between this large surface and its adjacent wall on the electrode assembly is even greater, easily causing damage to the structure of the electrode assembly, affecting the reliability of the battery cell, and further affecting the reliability of the battery device.

[0099] In view of this, in order to reduce the interference risk of the junction between the wall parts of the outer shell to the electrode assembly and improve the reliability of the battery device, some embodiments of the present application provide a battery cell, which includes an outer shell, an electrode assembly, and an electrode terminal. An accommodation cavity is formed inside the outer shell, and the outer shell includes a first wall, a second wall, and a third wall. Along the first direction x, the first wall and the third wall are oppositely arranged, the second wall is located between the first wall and the third wall, and the second wall connects the first wall and the third wall. The electrode assembly is arranged in the accommodation cavity. The electrode assembly is a laminated structure, and the first direction x is the lamination direction of the electrode assembly; or, the electrode assembly is a wound structure, the electrode assembly includes a planar region in the middle and corner regions on both sides, and the first direction x is the lamination direction of the electrode assembly in the planar region. The electrode terminal is arranged on the outer shell and is electrically connected to the electrode assembly, and the electrode terminal is located on other wall parts outside the first wall, the second wall, and the third wall of the outer shell. Wherein, the surface of the first wall facing the inside of the accommodation cavity is the first surface, the surface of the second wall facing the inside of the accommodation cavity is the second surface, the first surface and the second surface are directly connected, and the connection area forms a first preset angle, the first preset angle is not less than 85° and not greater than 95°.

[0100] In the related art, with the increase in the number of charge and discharge cycles of the battery cell, the battery cell expands internally, and the expansion force of the battery cell in the first direction x is relatively large, that is, the electrode assembly is more likely to expand in the direction of the first wall and the third wall. In the above solution, by setting the first surface of the first wall to be directly connected to the second surface of the second wall, and making the first preset angle between the first surface and the second surface be a right angle or an angle approaching a right angle, it is possible to improve the interference of the internal fillet between the first wall and the second wall to the electrode assembly, resulting in damage to the structure of the electrode assembly and reducing the reliability of the battery cell. Therefore, the reliability of the battery device can be effectively improved.

[0101] The battery device disclosed in the embodiments of the present application can be used, but is not limited to, power-consuming devices such as vehicles, ships, or aircraft. A power supply system of the power-consuming device can be composed of the battery device disclosed in the present application. In this way, it is beneficial to alleviate the problem of short circuit occurring during the use of the battery device, improve the use reliability of the battery device, and is also beneficial to increase the volume energy density of the battery device and extend the working time of the power-consuming device.

[0102] The embodiments of the present application provide a power-consuming device using the battery device as a power source. The power-consuming device can be, but is not limited to, mobile phones, tablets, laptop computers, electric toys, electric tools, battery cars, electric vehicles, ships, spacecraft, etc. Among them, the electric toys can include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric aircraft toys, etc. The spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc.

[0103] For the convenience of description, the following embodiments will take an electrical device in an embodiment of the present application as a vehicle as an example for illustration.

[0104] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of a vehicle 1000 in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, an extended-range vehicle, etc. A battery device 100 is provided inside the vehicle 1000. The battery device 100 can be provided at the bottom of the vehicle 1000, or at the head of the vehicle 1000, or at the tail of the vehicle 1000. The battery device 100 can be used to supply power to the vehicle 1000. For example, the battery device 100 can be used as the operating power source or the power source for use of the vehicle 1000. The vehicle 1000 can also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300. For example, it is used for the working power requirements during the start, navigation, and driving of the vehicle 1000.

[0105] In some embodiments of the present application, the battery device 100 can not only be used as the operating power source or the power source for use of the vehicle 1000, but also be used as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0106] Please refer to Figure 2 , Figure 2 which is an exploded perspective view of the battery device 100 in some embodiments of the present application.

[0107] The battery device 100 includes battery cells 10 and a box body 20. The battery cells 10 are accommodated in the box body 20. Among them, the box body 20 is used to provide an accommodation space for the battery cells 10, and the box body 20 can adopt various structures. In some embodiments, the box body 20 can include a first box body part 21 and a second box body part 22. The first box body part 21 and the second box body part 22 cover each other, and the first box body part 21 and the second box body part 22 jointly define an accommodation space for accommodating the battery cells 10. The second box body part 22 can be a hollow structure with one end open, and the first box body part 21 can be a plate-like structure. The first box body part 21 covers the open side of the second box body part 22 so that the first box body part 21 and the second box body part 22 jointly define an accommodation space; the first box body part 21 and the second box body part 22 can also both be hollow structures with one side open, and the open side of the first box body part 21 covers the open side of the second box body part 22. Of course, the box body 20 formed by the first box body part 21 and the second box body part 22 can be of various shapes, such as a cylinder, a cuboid, etc.

[0108] In a battery, the battery cells 10 can be one or more, and each battery cell 10 can be fixed to the box body 20 through a connecting member (such as a bolt), or each battery cell 10 can be fixed to the box body 20 by bonding.

[0109] In some embodiments, the battery cells 10 in the box body 20 can be electrically connected through a busbar component, so that the battery cells 10 in the box body 20 are connected in series, parallel or in a mixed connection. Exemplarily, a plurality of battery cell assemblies are provided in the box body 20, and each battery cell assembly includes a plurality of stacked battery cells 10, and the plurality of battery cells 10 are connected in series through a busbar component. In some embodiments, the plurality of battery cell assemblies can be connected in series through a busbar component.

[0110] According to some embodiments of the present application, a battery cell 10 is provided. Please refer to Figure 3 and Figure 4 , Figure 3 is a three-dimensional exploded view of the battery cell 10 in some embodiments of the present application, Figure 4 is a schematic diagram of the internal structures of the first wall 31, the second wall 32 and the electrode assembly 11 in some embodiments of the present application.

[0111] The battery cell 10 includes a housing 30, an electrode assembly 11 and electrode terminals 12. An accommodation cavity is formed inside the housing 30. The housing 30 includes a first wall 31, a second wall 32 and a third wall 33. Along the first direction x, the first wall 31 and the third wall 33 are disposed opposite to each other, the second wall 32 is located between the first wall 31 and the third wall 33, and the second wall 32 connects the first wall 31 and the third wall 33. The electrode assembly 11 is disposed in the accommodation cavity. The electrode assembly 11 is a stacked structure, and the first direction x is the stacking direction of the electrode assembly 11; or, the electrode assembly 11 is a wound structure, the electrode assembly 11 includes a planar region in the middle and corner regions on both sides, and the first direction x is the stacking direction of the electrode assembly 11 in the planar region. The electrode terminals 12 are disposed on the housing 30 and are electrically connected to the electrode assembly 11, and the electrode terminals 12 are located on other wall portions outside the first wall 31, the second wall 32 and the third wall 33 of the housing 30. Wherein, the surface of the first wall 31 facing the accommodation cavity is the first surface 310, the surface of the second wall 32 facing the accommodation cavity is the second surface 320, the first surface 310 and the second surface 320 are directly connected and the connection region forms a first preset angle, the first preset angle is not less than 85° and not more than 95°.

[0112] In some embodiments, the battery cell 10 includes a housing 30 and an electrode assembly 11, and the electrode assembly 11 and the electrolyte can be encapsulated in a closed space of the housing 30. The housing 30 can be a square housing 30, and the housing 30 includes a plurality of wall portions, and the plurality of wall portions are connected to each other and enclose an accommodation cavity for accommodating the electrode assembly 11.

[0113] In some embodiments, the outer shell 30 may include six wall portions, namely a first wall 31, a second wall 32, a third wall 33, a fourth wall 34, a fifth wall 35, and a sixth wall 36. Among them, along the circumferential direction of the outer shell 30, the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 may be connected end to end to form the circumferential wall of the outer shell 30, and the second wall 32 and the sixth wall 36 are disposed opposite to each other.

[0114] In some embodiments, the housing 30a may be made of a metal material, such as aluminum, steel, composite metal, etc. Or in some other embodiments, the housing 30a may be made of a non-metal material, such as plastic.

[0115] In some embodiments, the materials of the respective wall portions of the housing 30a may be the same or different. Exemplarily, the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 may be made of steel respectively, and the second wall 32 and the sixth wall 36 may be made of steel respectively; or the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 may be made of aluminum respectively, and the second wall 32 and the sixth wall 36 may be made of steel respectively; or, the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 may be made of steel respectively, and the second wall 32 and the sixth wall 36 may be made of aluminum respectively.

[0116] In some embodiments, the number of the electrode assemblies 11 may be one or more. Optionally, please refer to Figure 3 , the battery cell 10 includes two electrode assemblies 11, and the two electrode assemblies 11 are stacked in the outer shell 30.

[0117] The structural forms of the electrode assemblies 11 are diverse and may be a wound structure or a stacked structure. In some embodiments, the wound structure can be understood as an electrode assembly 11 formed by stacking a positive electrode plate, a separator, and a negative electrode plate and then winding them. Optionally, please refer to Figure 3 , Figure 3 The electrode assembly 11 in may be a wound structure, which includes a planar region in the middle and corner regions on both sides, that is, the electrode assembly 11 includes a plurality of straight segments and corner segments, and the plurality of straight segments are stacked along the first direction x, and adjacent two straight segments are connected by corner segments.

[0118] In some embodiments, the stacked structure can be understood as an electrode assembly 11 formed by stacking a plurality of groups of positive electrode plates, separators, and negative electrode plates along the first direction x, and the positive electrode plate and the negative electrode plate in each group are separated by a separator.

[0119] Generally, for the first direction x in the above description, when the battery cell 10 expands, it is the direction with a greater degree of expansion. When the housing 30 is a square housing 30, the wall surface of the housing 30 in the first direction x is the large surface. In some embodiments of the present application, the first wall 31 and the third wall 33 are the large surfaces of the housing 30, that is, the first wall 31 and the third wall 33 correspond to the wall portions that are more affected when the battery cell 10 expands.

[0120] In some embodiments, the first wall 31 and the third wall 33 can be the wall portions with a larger area of the housing 30, that is, the large surfaces. The second wall 32 can be the wall portion connecting the first wall 31 and the third wall 33, and the second wall 32 can be the bottom wall or the top wall of the housing 30. Exemplarily, in some usage scenarios of the battery cell 10, the second wall 32 is the bottom wall of the housing 30, and the second wall 32 can play a role in supporting the electrode assembly 11. In some other usage scenarios of the battery cell 10, when the battery cell 10 is used upside down, the second wall 32 can be the top wall of the housing 30.

[0121] The electrode terminal 12 is a component provided on the housing 30. The electrode terminal 12 is used to connect the tab of the electrode assembly 11 and an external busbar component to achieve the input and output of electrical energy of the battery cell 10. Exemplarily, one end of the electrode terminal 12 inside the battery cell 10 can be connected to the tab of the electrode assembly 11 through an adapter, and the end of the electrode terminal 12 outside the battery cell 10 can be connected to an external busbar component, which is used to allow current to flow into or out of the tab and the external busbar component through the electrode terminal 12. In some embodiments, the electrode terminal 12 can be a cylindrical structure, or a polygonal prism structure, or a composite structure of a cylindrical shape and a polygonal prism shape. In some embodiments, the electrode terminal 12 is made of a metal material, such as made of aluminum, copper, iron, steel, alloy or composite metal.

[0122] In some embodiments of the present application, the electrode terminal 12 is provided on other wall portions outside the first wall 31, the second wall 32 and the third wall 33, that is, the electrode terminal 12 is not provided on the first wall 31, the second wall 32 and the third wall 33. The electrode terminal 12 can be provided on the fourth wall 34, the fifth wall 35 or the sixth wall 36. The electrode terminal 12 can be electrically connected to the electrode assembly 11 through an adapter 12c.

[0123] In some embodiments, the battery cell 10 may include a first electrode terminal 12a and a second electrode terminal 12b. The polarities of the first electrode terminal 12a and the second electrode terminal 12b are opposite. For example, the first electrode terminal 12a is the positive electrode for connecting the positive electrode tab, and the second electrode terminal 12b is the negative electrode for connecting the negative electrode tab. The first electrode terminal 12a and the second electrode terminal 12b may be disposed on the same wall portion or different wall portions of the housing 30. Exemplarily, the sixth wall 36 may be provided on both the first electrode terminal 12a and the second electrode terminal 12b; alternatively, the first electrode terminal 12a is disposed on the fourth wall 34, and the second electrode terminal 12b is disposed on the fifth wall 35.

[0124] In some embodiments, the first surface 310 is the surface of the first wall 31 facing the accommodation cavity. Optionally, the first surface 310 may be the inner surface of the first wall 31, that is, along the thickness direction of the first wall 31, the first surface 310 is the surface of the first wall 31 closest to the electrode assembly 11. The second surface 320 is the surface of the second wall 32 facing the accommodation cavity. Optionally, the second surface 320 may be the inner surface of the second wall 32, that is, along the thickness direction z of the second wall 32, the second surface 320 is the surface of the second wall 32 closest to the electrode assembly 11.

[0125] "The first surface 310 and the second surface 320 are directly connected and the connection region forms a first preset angle" can be understood as that the first surface 310 and the second surface 320 may be flat surfaces, and there is no transition through other parts between them. For example, there is no transition through an inner fillet between the first surface 310 and the second surface 320, and the angle between the first surface 310 and the second surface 320 is the first preset angle. Optionally, please refer to Figure 4 , the flat first surface 310 and the flat second surface 320 are directly connected, and the first preset angle between the first surface 310 and the second surface 320 is 90° or approaches 90°. Exemplarily, please refer to Figure 4 , the first preset angle between the first surface 310 and the second surface 320 is R1. The value of R1 may be a value not less than 85° and not greater than 95°, such as 85°, 86°, 87°, 88°, 89°, 90°, 91°, 92°, 93°, 94°, 95° or any value between two adjacent values.

[0126] In some embodiments, the first wall 31 and the second wall 32 may be separate structures from each other, and the two are spliced together to form an integral body, so that the first surface 310 and the second surface 320 are directly connected and the connection area forms a first preset angle. Optionally, when manufacturing the housing 30, the second wall 32 is a plate-like structure, and the first wall 31 is positioned at the edge of the second wall 32, and the first wall 31 and the second wall 32 are combined into an integral body through a connection process, such as welding, bonding and other processes, so that there is no internal fillet between the first wall 31 and the second wall 32.

[0127] Optionally, the third wall 33 and the second wall 32 may be separate structures from each other, and the two are spliced together and combined into an integral body through processes such as welding and bonding. Optionally, the third wall 33 and the second wall 32 may be an integral structure, and the two may be formed by casting, die-casting or bending processes. Exemplarily, the second wall 32 may be bent on the third wall 33.

[0128] In the related art, as the number of charge and discharge cycles of the battery cell 10 increases, the battery cell 10 expands internally, and the expansion force of the battery cell 10 in the first direction x is relatively large, that is, the electrode assembly 11 is more likely to expand in the direction of the first wall 31 and the third wall 33. In the above solution, by setting the first surface 310 of the first wall 31 to be directly connected to the second surface 320 of the second wall 32, and making the first preset angle between the first surface 310 and the second surface 320 be a right angle or an angle approaching a right angle, it is possible to improve the interference of the internal fillet between the first wall 31 and the second wall 32 on the electrode assembly 11, resulting in damage to the structure of the electrode assembly 11 and reducing the reliability of the battery cell 10, thereby effectively improving the reliability of the battery device 100.

[0129] According to some embodiments of the present application, please refer to Figure 3 and Figure 4 , the electrode assembly 11 includes a main body 110 and an insulating film 111. The insulating film 111 covers at least a part of the main body 110, and the insulating film 111 is in direct contact with the second wall 32.

[0130] In some embodiments, the electrode assembly 11 includes a main body 110 and an insulating film 111. The main body 110 can be understood as the main structure of the electrode assembly 11 composed of a positive electrode plate, a negative electrode plate and a separator. The insulating film 111 is a film-like insulating structure covering at least a part of the main body 110. In some embodiments, the insulating film 111 may be a mylar film.

[0131] In some embodiments, the main body 110 has a lead-out end, and the tab is led out from the lead-out end. The insulating film 111 may cover other parts of the lead-out end of the main body 110; or the insulating film 111 covers the whole of the main body 110, and the tab is led out from the lead-out end and passes through the insulating film 111. Optionally, please refer toFigure 3 The main body 110 is roughly flat, and its upper end is a lead end. The insulating film 111 covers the peripheral wall and the lower end of the main body 110.

[0132] “The insulating film 111 is in direct contact with the second wall 32” can be understood as no other structural parts are arranged between the insulating film 111 and the second wall 32, and the insulating film 111 can be in direct contact with the second wall 32. In some embodiments, the second wall 32 is a wall portion without an electrode terminal 12, the second wall 32 can be a wall portion supporting the electrode assembly 11, and the second wall 32 can be in direct contact with the electrode assembly 11, and no structural parts such as a bottom support plate are arranged between the two.

[0133] In the above scheme, by setting the first surface 310 of the first wall 31 to be directly connected to the second surface 320 of the second wall 32, and making the first preset angle between the first surface 310 and the second surface 320 a right angle or an angle close to a right angle, there is no inner fillet between the first surface 310 and the second surface 320, thereby effectively reducing the risk of mutual interference between the electrode assembly 11 and the first surface 310 and the second surface 320, and then the bottom support plate in the related technology can be eliminated, and the insulating film 111 can be directly in contact with the second surface 320, so that the space utilization rate of the electrode assembly 11 can be improved, so as to achieve the effect of improving the volume energy density of the battery cell 10, and then facilitate the improvement of the volume energy density of the battery device 100.

[0134] According to some embodiments of the present application, the first wall 31 and the second wall 32 are formed by welding.

[0135] In some embodiments, the first wall 31 and the second wall 32 can be connected as one by a welding process. For example, in the process of welding the two, the first wall 31 and the second wall 32 can be positioned first, and the welding head can weld the first wall 31 and the second wall 32 along the thickness direction z of the second wall or along the thickness direction of the first wall 31, so as to melt the first wall 31 and the second wall 32 into one at the intersection of the first wall 31 and the second wall 32 and form a weld mark. Optionally, when welding along the thickness direction z of the second wall, the weld mark can be formed on the side of the second wall 32 away from the electrode assembly 11. When welding along the thickness direction of the first wall 31, the weld mark can be formed on the side of the first wall 31 away from the electrode assembly 11.

[0136] In the above solution, the two independent structures of the first wall 31 and the second wall 32 are welded together, so that there is no internal fillet between the first wall 31 and the second wall 32. On the one hand, it can improve the problem of interference of the joint part of the first wall 31 and the second wall 32 with the electrode assembly 11, and reduce the problem that the structure of the electrode assembly 11 is damaged and affects the reliability of the battery. On the other hand, the bottom plate in the related technology can be cancelled, so that the space utilization rate of the electrode assembly 11 can be improved to achieve the effect of improving the volume energy density of the battery cell 10, and further facilitate the improvement of the volume energy density of the battery device 100. On the other hand, the welding process is simple, the connection is reliable and the manufacturing efficiency is high, which is beneficial to the improvement of the manufacturing efficiency of the battery device 100.

[0137] In some other embodiments of the present application, the first wall 31 and the second wall 32 may be bonded together.

[0138] According to some embodiments of the present application, please refer to Figure 4 , the surface of the third wall 33 facing the accommodation cavity is the third surface 330. The third surface 330 and the second surface 320 are directly connected and the connection region forms a second preset angle. The second preset angle is not less than 85° and not greater than 95°.

[0139] Along the first direction x, the third wall 33 and the first wall 31 are opposite to each other. The third surface 330 is the surface of the third wall 33 facing the accommodation cavity. Optionally, the third surface 330 may be the inner surface of the third wall 33, that is, along the thickness direction of the third wall 33, the third surface 330 is the surface of the third wall 33 closest to the electrode assembly 11.

[0140] "The third surface 330 and the second surface 320 are directly connected and the connection region forms a second preset angle" can be understood as that the first surface 310 and the third surface 330 may be flat surfaces and there is no transition through other parts between them. For example, there is no transition through an internal fillet between the first surface 310 and the third surface 330, and the angle between the first surface 310 and the third surface 330 is the second preset angle. Optionally, please refer to Figure 4 , the flat first surface 310 and the flat third surface 330 are directly connected, and the second preset angle between the first surface 310 and the third surface 330 is 90° or approaches 90°. Exemplarily, please refer to Figure 4 , the second preset angle between the first surface 310 and the third surface 330 is R2. The value of R2 can be a value not less than 85° and not greater than 95°, such as 85°, 86°, 87°, 88°, 89°, 90°, 91°, 92°, 93°, 94°, 95° or any value between two adjacent values.

[0141] In some embodiments, the third wall 33 and the second wall 32 may be separate structures, and the splicing position of the two is integrated so that the first surface 310 and the third surface 330 are directly connected and the connection region forms a second preset angle. Optionally, when manufacturing the housing 30, the second wall 32 is a plate-like structure, and the third wall 33 is positioned at the edge of the second wall 32. The first wall 31 and the third wall 33 are combined into one body through a connection process. For example, the second wall 32 and the third wall 33 are combined into one body by using processes such as welding and bonding, so that there is no internal fillet between the third wall 33 and the second wall 32.

[0142] In the above solution, by setting the third surface 330 of the third wall 33 to be directly connected to the second surface 320 of the second wall 32 and making the second preset angle between the third surface 330 and the second surface 320 be a right angle or an angle approaching a right angle, it is possible to improve the interference of the internal fillet between the third wall 33 and the second wall 32 on the electrode assembly 11, resulting in damage to the structure of the electrode assembly 11 and reducing the reliability of the battery cell 10. Therefore, the reliability of the battery device 100 can be effectively improved.

[0143] In other embodiments of the present application, the third wall 33 and the second wall 32 may be an integral structure. Optionally, the third wall 33 is bent from the second wall 32. Optionally, the third wall 33 and the second wall 32 are formed by die-casting.

[0144] According to some embodiments of the present application, the third wall 33 and the second wall 32 are formed by welding.

[0145] In some embodiments, the third wall 33 and the second wall 32 may be connected into one body through a welding process. Exemplarily, during the process of welding the two into one body, the third wall 33 and the second wall 32 can be positioned first, and the welding head can weld the second wall 32 and the third wall 33 along the thickness direction z of the second wall or along the thickness direction of the third wall 33, so as to melt and integrate at the intersection of the second wall 32 and the third wall 33 and form a weld mark. Optionally, when welding along the thickness direction z of the second wall, the weld mark can be formed on the side of the second wall 32 facing away from the electrode assembly 11. When welding along the thickness direction of the third wall 33, the weld mark can be formed on the side of the third wall 33 facing away from the electrode assembly 11.

[0146] In the above solution, the two independent structures, i.e., the third wall 33 and the second wall 32, are welded into one body, so that there is no internal fillet between the third wall 33 and the second wall 32. On the one hand, it can improve the problem of interference of the intersection part of the third wall 33 and the second wall 32 with the electrode assembly 11, and reduce the problem that the structure of the electrode assembly 11 is damaged and affects the battery reliability; on the other hand, it can cancel the bottom plate in the related technology, thereby improving the space utilization rate of the electrode assembly 11 to achieve the effect of improving the volume energy density of the battery cell 10, and further facilitating the improvement of the volume energy density of the battery device 100; on the other hand, the welding process is simple, the connection is reliable and the manufacturing efficiency is high, which is conducive to the improvement of the manufacturing efficiency of the battery device 100.

[0147] In some other embodiments of the present application, the third wall 33 is bonded to the second wall 32.

[0148] According to some embodiments of the present application, please refer to Figure 3 and Figure 5 , Figure 5 which is a schematic structural view of the fourth wall 34, the fifth wall 35 and the second wall 32 in some embodiments of the present application.

[0149] The housing 30 further includes a fourth wall 34 and a fifth wall 35. Along the second direction y, the fourth wall 34 and the fifth wall 35 are opposite to each other, and the first direction x and the second direction y are perpendicular to each other. The surface of the fourth wall 34 facing the accommodation cavity is the fourth surface 340, and the fourth surface 340 is directly connected to the second surface 320 and the connection area forms a third preset angle, and the third preset angle is not less than 85° and not more than 95°; and / or the surface of the fifth wall 35 facing the accommodation cavity is the fifth surface 350, and the fifth surface 350 is directly connected to the second surface 320 and the connection area forms a fourth preset angle, and the fourth preset angle is not less than 85° and not more than 95°.

[0150] The fourth wall 34 and the fifth wall 35 are two wall parts of the housing 30 that are opposite to each other along the second direction y. In some embodiments, the first direction x may be the thickness direction of the battery cell 10, the second direction y may be the width direction of the battery cell 10, the first wall 31 and the third wall 33 may be the large surfaces of the housing 30, and the fourth wall 34 and the fifth wall 35 may be two side walls located between the first wall 31 and the third wall 33.

[0151] In some embodiments, the second wall 32 may be square, the first wall 31 and the third wall 33 are respectively arranged on two long sides of the second wall 32, and the fourth wall 34 and the fifth wall 35 are respectively arranged on two short sides of the second wall 32.

[0152] In some embodiments, the fourth surface 340 is the surface of the fourth wall 34 facing the accommodation cavity. Optionally, the fourth surface 340 may be the inner surface of the fourth wall 34, that is, along the thickness direction of the fourth wall 34, the fourth surface 340 is the surface of the fourth wall 34 closest to the electrode assembly 11.

[0153] In one embodiment, the fifth surface 350 is the surface of the fifth wall 35 facing the accommodation cavity. Optionally, the fifth surface 350 may be the inner surface of the fifth wall 35, that is, along the thickness direction of the fifth wall 35, the fifth surface 350 is the surface of the fifth wall 35 closest to the electrode assembly 11.

[0154] "The fourth surface 340 and the second surface 320 are directly connected and the connection area forms a third preset angle," which can be understood as that the fourth surface 340 and the second surface 320 can be flat surfaces, and there is no transition through other parts between them. For example, there is no transition through an inner fillet between the fourth surface 340 and the second surface 320, and the angle between the fourth surface 340 and the second surface 320 is the third preset angle. Optionally, please refer to Figure 5 , the flat fourth surface 340 and the flat second surface 320 are directly connected, and the third preset angle between the fourth surface 340 and the second surface 320 is 90° or approaches 90°. Exemplarily, please refer to Figure 5 , the third preset angle between the fourth surface 340 and the second surface 320 is R3. The value of R3 can be a value not less than 85° and not greater than 95°, such as 85°, 86°, 87°, 88°, 89°, 90°, 91°, 92°, 93°, 94°, 95° or any value between two adjacent values.

[0155] "The fifth surface 350 and the second surface 320 are directly connected and the connection area forms a fourth preset angle," which can be understood as that the fifth surface 350 and the second surface 320 can be flat surfaces, and there is no transition through other parts between them. For example, there is no transition through an inner fillet between the fifth surface 350 and the second surface 320, and the angle between the fifth surface 350 and the second surface 320 is the fourth preset angle. Optionally, please refer to Figure 5 , the flat fifth surface 350 and the flat second surface 320 are directly connected, and the fourth preset angle between the fifth surface 350 and the second surface 320 is 90° or approaches 90°. Exemplarily, please refer to Figure 5 , the fourth preset angle between the fourth surface 340 and the second surface 320 is R3. The value of R3 can be a value not less than 85° and not greater than 95°, such as 85°, 86°, 87°, 88°, 89°, 90°, 91°, 92°, 93°, 94°, 95° or any value between two adjacent values.

[0156] In some embodiments, the first wall 31 and the fourth wall 34 may be separate structures from each other, and the splicing position of the two is integrated, so that the first surface 310 and the fourth surface 340 are directly connected and the connection area forms a third preset angle. Optionally, when manufacturing the housing 30, the second wall 32 is a plate-like structure, the fourth wall 34 is positioned at the edge of the second wall 32, and the first wall 31 and the fourth wall 34 are combined into one body through a connection process, such as welding, bonding and other processes, so that there is no internal fillet between the first wall 31 and the fourth wall 34.

[0157] In some embodiments, the first wall 31 and the fifth wall 35 may be separate structures from each other, and the splicing position of the two is integrated, so that the first surface 310 and the fifth surface 350 are directly connected and the connection area forms a fourth preset angle. Optionally, when manufacturing the housing 30, the second wall 32 is a plate-like structure, the fifth wall 35 is positioned at the edge of the second wall 32, and the first wall 31 and the fifth wall 35 are combined into one body through a connection process, such as welding, bonding and other processes, so that there is no internal fillet between the first wall 31 and the fifth wall 35.

[0158] In some embodiments, the second wall 32, the fourth wall 34 and the fifth wall 35 may be separate structures from each other; in other embodiments of the present application, the second wall 32 and the fourth wall 34 may be an integral structure, and the two are integrally formed through processes such as casting, die-casting or bending. In other embodiments of the present application, the second wall 32 and the fifth wall 35 may be an integral structure, and the two are integrally formed through processes such as casting, die-casting or bending. In other embodiments of the present application, the second wall 32, the fourth wall 34 and the fifth wall 35 may be an integral structure, and the three may be integrally formed through processes such as casting, die-casting and the like. In other embodiments of the present application, the second wall 32, the third wall 33, the fourth wall 34 and the fifth wall 35 may be an integral structure, and the three may be integrally formed through processes such as casting, die-casting and the like.

[0159] In the above solution, by setting the fourth surface 340 of the fourth wall 34 to be directly connected to the second surface 320 of the second wall 32, and making the third preset angle between the fourth surface 340 and the second surface 320 a right angle or an angle approaching a right angle, the interference of the internal fillet between the fourth wall 34 and the second wall 32 on the electrode assembly 11 can be improved, so as to avoid the risk that the structure of the electrode assembly 11 is damaged and the reliability of the battery cell 10 is reduced. Thus, the reliability of the battery device 100 can be effectively improved. At the same time, by setting the fifth surface 350 of the fifth wall 35 to be directly connected to the second surface 320 of the second wall 32, and making the fourth preset angle between the fifth surface 350 and the second surface 320 a right angle or an angle approaching a right angle, the interference of the internal fillet between the fifth wall 35 and the second wall 32 on the electrode assembly 11 can be improved, so as to avoid the risk that the structure of the electrode assembly 11 is damaged and the reliability of the battery cell 10 is reduced. Thus, the reliability of the battery device 100 can be effectively improved.

[0160] According to some embodiments of the present application, the fourth wall 34 and the second wall 32 are formed by welding; and / or the fifth wall 35 and the second wall 32 are formed by welding.

[0161] In some embodiments, the fourth wall 34 and the second wall 32 can be connected into one body by a welding process. Exemplarily, during the process of welding them into shape, the fourth wall 34 and the second wall 32 can be positioned first, and the welding head can weld the fourth wall 34 and the second wall 32 along the thickness direction z of the second wall or along the thickness direction of the fourth wall 34, so as to melt and integrate into one body at the intersection of the fourth wall 34 and the second wall 32 and form a weld mark. Optionally, when welding along the thickness direction z of the second wall, the weld mark can be formed on the side of the second wall 32 away from the electrode assembly 11. When welding along the thickness direction of the fourth wall 34, the weld mark can be formed on the side of the fourth wall 34 away from the electrode assembly 11.

[0162] In some embodiments, the fifth wall 35 and the second wall 32 can be connected into one body by a welding process. Exemplarily, during the process of welding them into shape, the fifth wall 35 and the second wall 32 can be positioned first, and the welding head can weld the fifth wall 35 and the second wall 32 along the thickness direction z of the second wall or along the thickness direction of the fifth wall 35, so as to melt and integrate into one body at the intersection of the fifth wall 35 and the second wall 32 and form a weld mark. Optionally, when welding along the thickness direction z of the second wall, the weld mark can be formed on the side of the second wall 32 away from the electrode assembly 11. When welding along the thickness direction of the fifth wall 35, the weld mark can be formed on the side of the fifth wall 35 away from the electrode assembly 11.

[0163] In the above solution, two independent structures, namely the fourth wall 34 and the second wall 32, are welded into one body, and two independent structures, namely the fifth wall 35 and the second wall 32, are welded together by wire, so that there is no internal fillet between the fourth wall 34 and the second wall 32 and between the fifth wall 35 and the second wall 32. On the one hand, it can improve the interference problem of the intersection of the fourth wall 34 and the second wall 32 and the intersection of the fifth wall 35 and the second wall 32 with the electrode assembly 11, and reduce the problem that the structure of the electrode assembly 11 is damaged and affects the battery reliability; on the other hand, it can cancel the bottom support plate in the related technology, thereby improving the space utilization rate of the electrode assembly 11 to achieve the effect of improving the volume energy density of the battery cell 10, and further facilitating the improvement of the volume energy density of the battery device 100; on the third hand, the welding process is simple, the connection is reliable and the manufacturing efficiency is high, which is conducive to the improvement of the manufacturing efficiency of the battery device 100.

[0164] According to some embodiments of the present application, the outer shell 30 includes a housing 30a, the housing 30a is an integral structure, the housing 30a includes a first wall 31, a third wall 33, a fourth wall 34 and a fifth wall 35. Along the thickness direction z of the second wall, one end of the housing 30a has a first opening 30b, and the second wall 32 closes the first opening 30b.

[0165] In some embodiments, the outer shell 30 includes a housing 30a and a second wall 32. The housing 30a is an integral structure with a first opening 30b. The second wall 32 and the housing 30a are separate structures, and the two are combined into one body through a connection process. For example, the housing 30a is connected to the edge of the second wall 32 by welding, and the second wall 32 can close the first opening 30b.

[0166] Exemplarily, when assembling the battery cell 10, the electrode assembly 11 can be placed into the interior of the housing 30a through the first opening 30b, and then the second wall 32 is connected to the housing 30a to cover the first opening 30b, so that the electrode assembly 11 is in a closed space. Finally, the electrolyte is injected into the closed space through the liquid injection hole on the outer shell 30 and the liquid injection hole is closed.

[0167] Or, when assembling the battery cell 10, the electrode assembly 11 and the electrolyte can be arranged inside the housing 30a through the first opening 30b, and then the second wall 32 is connected to the housing 30a to cover the first opening 30b, so that the electrode terminal 12 and the electrolyte are in a closed space.

[0168] Optionally, please refer to Figure 6 , Figure 6This is an exploded perspective view of the outer casing 30 in some embodiments of the present application. The housing 30a is an integral structure and can be formed by processes such as casting, bending and welding processes. During the assembly process of the battery cell 10, the housing 30a comes in as a whole to be connected to the second wall 32. The housing 30a includes a first wall 31, a third wall 33, a fourth wall 34 and a fifth wall 35. Along the circumferential direction of the outer casing 30, the first wall 31, the third wall 33, the fourth wall 34 and the fifth wall 35 are connected end to end to jointly form a cylindrical structure. One end of the housing 30a forms a first opening 30b, and the other end forms a second opening 30c. The second wall 32 closes the first opening 30b, and the second opening 30c is closed by a sixth wall 36.

[0169] Optionally, please refer to Figure 7 , Figure 7 This is an exploded perspective view of the outer casing 30 in some other embodiments of the present application. The housing 30a is an integral structure and can be integrally formed by casting, die-casting or stamping processes. The housing 30a includes a first wall 31, a third wall 33, a fourth wall 34, a fifth wall 35 and a sixth wall 36. Along the circumferential direction of the outer casing 30, the first wall 31, the third wall 33, the fourth wall 34 and the fifth wall 35 are connected end to end and are disposed around the edge of the sixth wall 36. One end of the housing 30a facing away from the sixth wall 36 forms a first opening 30b, and the second wall 32 closes the first opening 30b.

[0170] In the above solution, the integral housing 30a includes a first wall 31, a third wall 33, a fourth wall 34 and a fifth wall 35. By connecting the second wall 32 to the first wall 31, the third wall 33, the fourth wall 34 and the fifth wall 35 respectively, on the one hand, it can close the first opening 30b of the housing 30a to be able to support the electrode assembly 11 or provide a closed space for the electrode assembly 11. On the other hand, it can make the intersection part between the housing 30a and the second wall 32 have no internal fillet to reduce the interference of the housing 30a on the electrode assembly 11, so that the bottom support plate in the related art can be cancelled to balance the reliability of the battery cell 10 and the improvement of the energy density; on the other hand, during the manufacturing process, the assembly difficulty of the integral housing 30a and the first wall 31 is small, so the manufacturing efficiency of the battery cell 10 is high, and thus the manufacturing efficiency of the battery device 100 is high.

[0171] According to some embodiments of the present application, please refer to Figure 6 , the outer casing 30 further includes a sixth wall 36. Along the thickness direction z of the second wall, the other end of the housing 30a has a second opening 30c, and the sixth wall 36 closes the second opening 30c.

[0172] The housing 30 includes a housing body 30a, a sixth wall 36, and a second wall 32. The housing body 30a is an integral structure. Along the thickness direction z of the second wall, one end of the housing body 30a has a first opening 30b, and the other end has a second opening 30c. The second wall 32 is connected to one end of the housing body 30a to close the first opening 30b, and the sixth wall 36 is connected to the other end of the housing body 30a to close the second opening 30c.

[0173] Optionally, the second wall 32 can be welded to one ends of the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35. Optionally, the sixth wall 36 can be welded to the other ends of the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35.

[0174] In the above solution, the housing 30 includes a housing body 30a, a sixth wall 36, and a second wall 32 which are separate structures from each other and are respectively connected to each other. On the one hand, it improves the problem that the interference of the electrode assembly 11 at the junction of the housing body 30a and the second wall 32 causes damage to the structure of the electrode assembly 11 and affects the reliability of the battery cell 10. On the other hand, during the manufacturing and assembly processes of the battery cell 10, it can reduce the forming difficulty of the housing 30 and the manufacturing cost of the battery cell 10.

[0175] According to some embodiments of the present application, please refer to Figure 6 , along the circumferential direction of the housing 30, the opposite ends of the fourth wall 34 are respectively bent on the first wall 31 and the third wall 33. Along the circumferential direction of the housing 30, the fifth wall 35 includes a first part 351 and a second part 352. The first part 351 is bent on the first wall 31, and the second part 352 is bent on the third wall 33. The first part 351 and the second part 352 are welded and formed.

[0176] In some embodiments, the housing 30 can be formed by bending and welding a plate-like structural member. For example, the housing 30 is bent from a steel sheet, and the first part 351, the first wall 31, the fourth wall 34, the third wall 33, and the second part 352 are bent through the bending process. The first part 351 and the second part 352 are combined into one body through the welding process to form the fifth wall 35. Please refer to Figure 6 , Figure 6 shows a weld mark C formed by welding the first part 351 and the second part 352.

[0177] In the above solution, a shell-like structural member can be formed by bending a plate-like structure, and the first part 351 and the second part 352 are connected to each other by cooperating with the welding process to form the housing body 30a. That is, the manufacturing of the housing body 30a can be completed through the bending process and one welding process, so that the manufacturing process of the housing body 30a is simple, the process cycle is fast, which is beneficial to the improvement of the manufacturing efficiency of the battery cell 10, and further beneficial to the improvement of the manufacturing efficiency of the battery device 100.

[0178] In some other embodiments, the housing 30a can also be made by a casting process.

[0179] In some other embodiments according to the present application, please refer to Figure 7 , the housing 30a further includes a sixth wall 36. Along the circumferential direction of the outer shell 30, the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 surround the edge of the sixth wall 36. Along the thickness direction of the second wall 32, the sixth wall 36 and the second wall 32 are opposite to each other.

[0180] The outer shell 30 includes a housing 30a and a second wall 32 which are of a split structure. The housing 30a is an integral structure, which includes a first wall 31, a third wall 33, a fourth wall 34, a fifth wall 35, and a sixth wall 36. The first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 surround the edge of the sixth wall 36 to form a first opening 30b at one end of the housing 30a, and the second wall 32 closes the first opening 30b.

[0181] In some embodiments, the housing 30a can be formed by a casting, die-casting, or stamping process.

[0182] In the above solution, the housing 30a which is an integral structure includes a sixth wall 36 and the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 surrounding the edge of the sixth wall 36, so that the housing 30a has a cylindrical structure with one end closed and the other end open. On the one hand, it is beneficial to the assembly of the electrode assembly 11, reducing the assembly process of the battery cell 10 and improving the manufacturing efficiency of the battery device 100. On the other hand, it reduces the connection interfaces on the surface of the outer shell 30, which is beneficial to improving the airtightness of the battery cell 10 and the reliability of the battery cell 10, and further beneficial to improving the reliability of the battery device 100.

[0183] In some other embodiments according to the present application, please refer to Figure 7 , the electrode terminal 12 is arranged on the sixth wall 36.

[0184] In some embodiments, the battery cell 10 is placed vertically. The second wall 32 can be the bottom wall of the outer shell 30, which has the function of supporting the electrode assembly 11. The sixth wall 36 can be the top wall of the outer shell 30, which can play the role of installing the electrode terminal 12.

[0185] In some embodiments, the first electrode terminal 12a and the second electrode terminal 12b are respectively arranged on the sixth wall 36.

[0186] In some embodiments, when assembling the battery cell 10, the electrode terminal 12 is mounted on the sixth wall 36, the electrode assembly 11 can be disposed inside the housing 30a through the first opening 30b, the electrode terminal 12 is connected to the tab of the electrode assembly 11, and then the second wall 32 is connected to the housing 30a to cover the first opening 30b.

[0187] In the above solution, by disposing the electrode terminal 12 at the sixth end to connect with the tab lead-out end of the electrode assembly 11, the second wall 32 can contact the other end of the electrode terminal 12 without being interfered by the joint portion between the second wall 32 and the housing 30a, so that the bottom plate in the related art can be cancelled, which is beneficial to the improvement of the volumetric energy density of the battery cell 10 and the volumetric energy density of the battery device 100.

[0188] According to other embodiments of the present application, the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 are separate structures from each other. The opposite ends of the fourth wall 34 along the second direction y are respectively welded to the first wall 31 and the third wall 33, and the opposite ends of the fifth wall 35 along the second direction y are respectively welded to the first wall 31 and the third wall 33.

[0189] In some embodiments, the outer shell 30 can be formed by splicing multiple separate structures. For example, the outer shell 30 can be formed by welding multiple steel plates.

[0190] Optionally, the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 are respectively independent plate-like structures. The opposite ends of the fourth wall 34 along the second direction y are respectively welded to the first wall 31 and the third wall 33, and the opposite ends of the fifth wall 35 along the second direction y are respectively welded to the first wall 31 and the third wall 33. Along the thickness direction z of the second wall, one ends of the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 are respectively welded to the second wall 32, and the other ends of the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 are respectively welded to the sixth wall 36.

[0191] In the above solution, the outer shell 30 is formed by welding multiple separate structures, which can effectively reduce the interference of the connection interfaces between the inner walls of the outer shell 30 on the electrode assembly 11, is beneficial to the improvement of the space utilization rate of the battery assembly, thus beneficial to the improvement of the volumetric energy density of the battery cell 10, and further beneficial to the improvement of the volumetric energy density of the battery device 100.

[0192] According to some embodiments of the present application, along the thickness direction z of the second wall, the electrode terminal 12 is disposed on the wall of the outer shell 30 opposite to the second wall 32.

[0193] In some embodiments, along the thickness direction z of the second wall, the second wall 32 is disposed on one side of the electrode assembly 11 , and the first electrode terminal 12 a and the second electrode terminal 12 b are disposed on the other side of the electrode assembly 11 .

[0194] Optionally, along the thickness direction z of the second wall, the housing 30 includes a second wall 32 and a sixth wall 36 opposite to each other, and the electrode terminal 12 is disposed on the sixth wall 36. In some embodiments, the sixth wall 36 may be an independent structure, for example, the sixth wall 36 is in the shape of a plate, and the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 are disposed around the edge of the sixth wall 36. Alternatively, the sixth wall 36 is a partial structure of the housing 30a, and the housing 30a is an integral structure, including the first wall 31, the third wall 33, the fourth wall 34, the fifth wall 35, and the sixth wall 36.

[0195] In the above scheme, the electrode terminal 12 is arranged on the side of the shell 30 away from the second wall 32, that is, the electrode assembly 11 is a single-sided electrode ear, which can reduce the space occupied by the electrode terminal 12 and the electrode assembly 11 in the thickness direction z of the second wall, which is beneficial to the improvement of the volume energy density of the battery cell 10 and the volume energy density of the battery device 100.

[0196] According to other embodiments of the present application, see Figure 8 , Figure 8 Schematic diagram of battery cells 10 in other embodiments of the present application. The electrode terminal 12 is disposed on the wall of the housing 30 along the second direction y, and the first direction x, the second direction y, and the thickness direction z of the second wall are perpendicular to each other.

[0197] In some embodiments, the electrode terminal 12 is disposed on the wall portion of the outer shell 30 along the second direction y, for example, the first electrode terminal 12a and the second electrode terminal 12b are respectively disposed on the fourth wall 34 and the fifth wall 35 of the outer shell 30 opposite to each other along the second direction y; or the first electrode terminal 12a and the second terminal are respectively disposed on the fourth wall 34.

[0198] Optionally, the shell 30 is blade-shaped, the first direction x is the thickness direction of the shell 30, the second direction y is the length direction of the shell 30, the size of the shell 30 in the second direction y is larger than the size in the first direction x, and the size of the shell 30 in the second direction y is larger than the size in the thickness direction z of the second wall.

[0199] In the above solution, by disposing the electrode terminal 12 on the wall portion of the housing 30 along the second direction y, the occupation of the space in the thickness direction z and the first direction x of the second wall by the electrode terminal 12 and the electrode assembly 11 can be reduced, which is beneficial to improving the volume energy density of the battery cell 10 and the volume energy density of the battery device 100. In the related art, especially in the blade battery, the surface of the housing 30 along the second direction y is a side surface (small surface). By disposing the electrode terminal 12 on the side surface, the characteristics of high volume energy density of the blade battery can be fully utilized to further improve the volume energy density of the battery device 100.

[0200] According to some other embodiments of the present application, the electrode terminal 12 includes a first electrode terminal 12a and a second electrode terminal 12b with opposite polarities. The first electrode terminal 12a is disposed on one wall portion of the housing 30 along the second direction y, and the second electrode terminal 12b is disposed on another wall portion of the housing 30 along the second direction y.

[0201] In some embodiments, along the second direction y, the housing 30 includes a fourth wall 34 and a fifth wall 35 that are opposite to each other. The first electrode terminal 12a can be disposed on the fourth wall 34, and the second electrode terminal 12b can be disposed on the fifth wall 35.

[0202] In the above solution, by respectively disposing the first electrode terminal 12a and the second electrode terminal 12b with opposite polarities on two wall portions of the housing 30 that are opposite to each other along the second direction y, the negative charge state distribution can be made more uniform, thereby reducing the risk of lithium plating, effectively reducing the risk of internal short circuit and heat generation inside the battery cell 10, improving the reliability of the battery cell 10, and being beneficial to improving the reliability of the battery device 100.

[0203] According to some embodiments of the present application, the material of the housing 30 is steel, and the thickness of the housing 30 is not less than 0.075 mm and not more than 0.3 mm.

[0204] In some embodiments, the material of the housing 30 is steel. For example, the materials of the first wall 31, the second wall 32, the third wall 33, the fourth wall 34, the fifth wall 35, and the sixth wall 36 are all steel.

[0205] In some embodiments, the thickness of the housing 30 is not less than 0.075 mm and not more than 0.3 mm. For example, the thickness value of the housing 30 can be 0.075 mm, 0.080 mm, 0.085 mm, 0.090 mm, 0.095 mm, 0.1 mm, 0.105 mm... 0.295, 0.3 mm, or any value between two adjacent values.

[0206] In some embodiments, the thickness of the outer shell 30 can be measured by a dimension measurer, a laser rangefinder or other means or devices.

[0207] In the above solution, the material of the outer shell 30 is selected as steel with relatively high structural strength, so that on the basis that the whole battery cell 10 has relatively high structural strength, the wall thickness of the housing 30a can be greatly reduced. For example, the thickness of the outer shell 30 is limited to be not less than 0.075 mm and not more than 0.3 mm, so that the proportion of the housing 30a in the battery cell 10 can be reduced, and further the battery cell 10 has a relatively high volume energy density, which is beneficial to the improvement of the volume energy density of the battery device 100.

[0208] According to some embodiments of the present application, please refer to Figure 9 , Figure 9 is Figure 4 the enlarged view of part A in

[0209] The first wall 31 and the second wall 32 are connected by a first connecting portion 13. The first surface 310 is in contact with the outer peripheral surface of the second wall 32. Along the first direction x, the first connecting portion 13 is located between the first surface 310 and the outer peripheral surface of the second wall 32, and a part of the first connecting portion 13 is located on the side of the second wall 32 away from the accommodation cavity.

[0210] In some embodiments, the first wall 31 and the second wall 32 are formed by welding, and the first connecting portion 13 can be a welding mark formed by welding the first wall 31 and the second wall 32 to each other. Please refer to Figure 9 , the outer peripheral surface of the second wall 32 can be adjacent to the first surface 310 of the first wall 31. The first connecting portion 13 can be located between the first surface 310 and the outer peripheral surface of the second wall 32, and part of it is exposed on the side of the second wall 32 away from the electrode assembly 11.

[0211] Optionally, the second wall 32 is integrally in a flat plate shape. The second wall 32 is located between the first wall 31 and the third wall 33. One side of the second wall 32 in the first direction x abuts against the first surface 310, and the other side in the first direction x abuts against the third surface 330. The welding head welds the joint part of the first wall 31 and the second wall 32 along the direction of the second wall 32 pointing to the sixth wall 36 to form the first connecting portion 13.

[0212] In the above solution, the first surface 310 is connected to the second wall 32 through the first connecting portion 13 and the first surface 310 is in contact with the outer peripheral surface of the second wall 32. With part of the first connecting portion 13 located on the side of the second wall 32 away from the accommodation cavity, the connection difficulty between the first wall 31 and the second wall 32 can be low. For example, welding the joint part of the first wall 31 and the second wall 32 from the side of the first wall 31 away from the accommodation cavity can effectively improve the connection efficiency between the first wall 31 and the second wall 32, and further improve the manufacturing efficiency of the battery cell 10.

[0213] In some embodiments of the present application, the first connecting portion 13 includes a welding mark formed between the first wall 31 and the second wall 32.

[0214] In some embodiments, the first wall 31 and the second wall 32 are formed by welding, and the first connecting portion 13 may be a welding mark formed by welding the first wall 31 and the second wall 32 to each other.

[0215] In the above solution, the first wall 31 and the second wall 32 are combined into one body through a welding process, and a welding mark is formed between the two, which can effectively improve the connection reliability between the first wall 31 and the second wall 32, reduce the risk of the two separating from each other, make the battery cell 10 have high reliability, and is conducive to improving the reliability of the battery device 100.

[0216] In other embodiments of the present application, the first wall 31 and the second wall 32 may also be combined into one body by bonding, and the first connecting portion 13 may include a bonding structure formed between the first wall 31 and the second wall 32.

[0217] In other embodiments of the present application, please refer to Figure 10 and Figure 11 , Figure 10 is a schematic structural diagram of the first wall 31, the second wall 32 and the third wall 33 in other embodiments of the present application, Figure 11 is Figure 10 The enlarged view of B in

[0218] The first wall 31 and the second wall 32 are connected through the first connecting portion 13. Along the thickness direction z of the second wall, a convex portion 321 is formed on the side of the second wall 32 facing the accommodation cavity. The outer peripheral surface of the convex portion 321 contacts the first surface 310. Along the thickness direction z of the second wall, the first connecting portion 13 is located between the end surface of the first wall 31 and the second wall 32.

[0219] In some embodiments, the first wall 31 and the second wall 32 are formed by welding, and the first connecting portion 13 may be a welding mark formed by welding the first wall 31 and the second wall 32 to each other.

[0220] Please refer to Figure 11 , the second wall 32 may include a main body 322 and a convex portion 321 arranged along its thickness direction. The convex portion 321 protrudes from the surface of the main body 322 facing the electrode assembly 11. The first surface 310 of the first wall 31 abuts against the outer peripheral surface of the convex portion 321, and the end of the first wall 31 abuts against the surface of the main body 322 facing the electrode assembly 11. The first connecting portion 13 is formed between the end of the first wall 31 and the main body.

[0221] Optionally, the second wall 32 is formed with a body 322 and a convex portion 321 by stamping. The convex portion 321 is located between the first wall 31 and the third wall 33. One side of the convex portion 321 in the first direction x abuts against the first surface 310, and the other side in the first direction x abuts against the third surface 330. The end portions of the first wall 31 and the third wall 33 respectively abut against the surface of the body 322. The welding head welds the portion where the first wall 31 and the second wall 32 meet along the direction from the first wall 31 to the third wall 33 to form the first connection portion 13.

[0222] In the above solution, by providing the convex portion on the side of the second wall 32 facing the accommodation cavity, the second wall 32 and the first wall 31 can be positioned relative to each other, the risk of misalignment between the second wall 32 and the first wall 31 can be reduced, thereby improving the connection reliability between the first wall 31 and the second wall 32, which is beneficial to enhancing the structural reliability of the battery cell 10.

[0223] In some embodiments of the present application, the first connection portion 13 includes a welding mark formed between the first wall 31 and the second wall 32.

[0224] In some embodiments, the first wall 31 and the second wall 32 are welded and formed, and the first connection portion 13 can be a welding mark formed by welding the first wall 31 and the second wall 32 to each other.

[0225] In the above solution, the first wall 31 and the second wall 32 are combined into one body through a welding process, and a welding mark is formed between the two, which can effectively improve the connection reliability between the first wall 31 and the second wall 32, reduce the risk of their separation from each other, make the battery cell 10 have high reliability, and is beneficial to enhancing the reliability of the battery device 100.

[0226] In some other embodiments of the present application, the first wall 31 and the second wall 32 can also be combined into one body by bonding, and the first connection portion 13 can include a bonding structure formed between the first wall 31 and the second wall 32.

[0227] According to some embodiments of the present application, there is also provided a battery device 100, which includes the battery cell 10 described above.

[0228] Please refer to Figure 2 , the battery device 100 includes the battery cell 10 and a box body 20, and the battery cell 10 is accommodated in the box body 20.

[0229] Optionally, a plurality of battery cell assemblies are provided in the box body 20. Each battery cell assembly includes a plurality of battery cells 10 stacked on top of each other, and the plurality of battery cells 10 are connected in series with each other through a bus bar component. In some embodiments, the plurality of battery cell assemblies can be connected in series with each other through a bus bar component.

[0230] According to some embodiments of the present application, an electrical device is further provided. The electrical device includes the battery cell 10 provided above, and / or the battery device 100 provided above. The battery cell 10 provided above and / or the battery device 100 provided above are used to provide electrical energy.

[0231] Optionally, the electrical device is a vehicle 1000, and the battery cell 10 can be used as the driving power source and / or the control power source of the vehicle 1000.

[0232] According to some embodiments of the present application, a battery cell 10 is provided. Please refer to Figures 3 - 11 , the battery cell 10 includes a housing 30, an electrode assembly 11, and electrode terminals 12. The housing 30 is a steel shell with a thickness not less than 0.15 mm and not greater than 0.25 mm. The electrode assembly 11 is disposed in the accommodation cavity of the housing 30, and the electrode terminals 12 are disposed on the wall of the housing 30 and electrically connected to the electrode assembly 11. The electrode terminals 12 may include a first electrode terminal 12a and a second electrode terminal 12b with opposite polarities.

[0233] The housing 30 is a square housing 30, including a first wall 31, a second wall 32, a third wall 33, a fourth wall 34, a fifth wall 35, and a sixth wall 36. The first wall 31 and the third wall 33 are opposite to each other along a first direction x, the fourth wall 34 and the fifth wall 35 are opposite to each other along a second direction y, and the second wall 32 and the sixth wall 36 are opposite to each other along the thickness direction z of the second wall. Among them, the first wall 31 and the third wall 33 are the large faces of the housing 30, that is, the outer surface areas of the outside of the first wall 31 and the third wall 33 are the wall parts with the largest surface areas. In the battery cell 10 provided in some embodiments of the present application, no bottom plate is provided between the electrode assembly 11 and the second wall 32, and the insulating film 111 covering the outer periphery of the main body 110 of the electrode assembly 11 can be in direct contact with the second wall 32.

[0234] In some embodiments of the present application, the second wall 32 is at least an independent structure from the first wall 31. For example, the second wall 32 is an independent structural member, the first wall 31 is an independent structural member, and the two are welded together with other wall parts of the housing 30. For example, the second wall 32 is an independent structural member, the first wall 31 and some other wall parts of the housing 30 are an integral structure, and the first wall 31 and the second wall 32 are connected by welding, so that there is no inner fillet at the intersection of the second wall 32 and a large face of the housing 30.

[0235] In some embodiments of the present application, the second wall 32 is an independent structure from the first wall 31, and the second wall 32 is also an independent structure from the third wall 33. The second wall 32 is connected to the first wall 31 and the third wall 33 respectively by welding, so that there is no inner fillet at the intersection of the second wall 32 and the large face of the housing 30.

[0236] In some embodiments of the present application, the second wall 32 and the first wall 31 are independent structures from each other, the second wall 32 and the third wall 33 are independent structures from each other, the second wall 32 and the fourth wall 34 are independent structures from each other, the second wall 32 and the fifth wall 35 are independent structures from each other. The second wall 32 is respectively connected to the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 by welding, so that there are no internal rounded corners at the junction parts of the second wall 32 and other wall parts of the housing 30.

[0237] Optionally, please refer to Figure 3 and Figure 6 , the housing 30 includes a housing body 30a, a second wall 32, and a sixth wall 36. The housing body 30a is an integral structure, which includes a first wall 31, a third wall 33, a fourth wall 34, and a fifth wall 35 integrated into one body. The housing body 30a can be formed by processes such as casting and bending. Exemplarily, the housing body 30a can be formed by bending a plate-shaped steel to form the first wall 31, the third wall 33, the fourth wall 34, and a first part 351 and a second part 352. The first part 351 and the second part 352 are welded to each other to form the fifth wall 35, and the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 are connected into one body to form the housing body 30a. One end of the housing body 30a forms a first opening 30b, and the other end forms a second opening 30c. The second wall 32 is connected to the housing body 30a and closes the first opening 30b, and the sixth wall 36 closes the second opening 30c. The first electrode terminal 12a and the second electrode terminal 12b can be respectively arranged on the sixth wall 36. In some embodiments, creases can be pre-set on the surface of the plate-shaped steel so that it can be bent along the creases, thereby improving the bending efficiency.

[0238] The edges of the sixth wall 36 can be respectively welded to the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35.

[0239] Please refer to Figure 4 and Figure 5 , two long sides of the second wall 32 opposite to each other along the first direction x are respectively welded to the first wall 31 and the third wall 33. Two short sides of the second wall 32 opposite to each other along the second direction y are respectively welded to the fourth wall 34 and the fifth wall 35.

[0240] The second surface 320 of the second wall 32 is directly connected to the first surface 310 of the first wall 31, there is no internal fillet between them, and the first preset angle between them is not less than 85° and not more than 95°, for example, the first preset angle is 90°. The third surface 330 of the third wall 33 is directly connected to the first surface 310 of the first wall 31, there is no internal fillet between them, and the second preset angle between them is not less than 85° and not more than 95°, for example, the second preset angle is 90°. The fourth surface 340 of the fourth wall 34 is directly connected to the first surface 310 of the first wall 31, there is no internal fillet between them, and the third preset angle between them is not less than 85° and not more than 95°, for example, the third preset angle is 90°. The fifth surface 350 of the fifth wall 35 is directly connected to the first surface 310 of the first wall 31, there is no internal fillet between them, and the fourth preset angle between them is not less than 85° and not more than 95°, for example, the fourth preset angle is 90°.

[0241] Optionally, please refer to Figure 7 , the housing 30 includes a housing body 30a and a second wall 32. The housing body 30a is an integral structure, including a first wall 31, a third wall 33, a fourth wall 34, a fifth wall 35 and a sixth wall 36 that are connected to each other. The housing body 30a can be integrally formed by a casting process, a die-casting process, a stamping process or other processes. One end of the housing body 30a forms a first opening 30b, and the second wall 32 closes the first opening 30b and the second wall 32 and the sixth wall 36 are opposite to each other. In some embodiments, the first electrode terminal 12a and the second electrode terminal 12b can be respectively disposed on the sixth wall 36. In some embodiments, the two long sides of the second wall 32 opposite to each other along the first direction x are respectively welded to the first wall 31 and the third wall 33. The two short sides of the second wall 32 opposite to each other along the second direction y are respectively welded to the fourth wall 34 and the fifth wall 35.

[0242] Optionally, please refer to Figure 8 , the battery cell 10 can be in a blade shape, its length direction is greater than the thickness direction and greater than the height direction. In some embodiments, along the length direction of the battery cell 10, the fourth wall 34 and the fifth wall 35 can be opposite to each other, along the height direction of the battery cell 10, the second wall 32 and the sixth wall 36 are opposite to each other, and along the thickness direction of the battery cell 10, the first wall 31 and the third wall 33 are opposite to each other. The first electrode terminal 12a can be disposed on the fourth wall 34, and the second electrode terminal 12b can be disposed on the fifth wall 35. Among them, the first wall 31, the third wall 33, the fourth wall 34 and the fifth wall 35 can surround the second wall 32 and are respectively welded to the second wall 32, so that there is no internal fillet at the junction of the housing body 30a and the second wall 32, so that no bottom support plate is provided between the electrode assembly 11 and the second wall 32.

[0243] Optionally, in some embodiments, refer toFigure 9 The second wall 32 may be in a flat plate shape. The outer peripheral surfaces of the second wall 32 may be in contact with the first surface 310, the third surface 330, the fourth surface 340, and the fifth surface 350 respectively. The part where the second wall 32 contacts the housing 30a may be welded from the outside of the second wall 32 (the side away from the electrode assembly 11), that is, the second wall 32 and the housing 30a are integrated by means of bottom welding. In this welding method, taking the second wall 32 as the bottom wall, the welding mark between the second wall 32 and the housing 30a is located at the bottom of the outer shell 30.

[0244] Optionally, in some embodiments, refer to Figure 11 The second wall 32 may include a body 322 and a convex portion 321 arranged along its thickness direction. The convex portion 321 protrudes from the surface of the body 322 facing the electrode assembly 11. The outer peripheral surfaces of the convex portion 321 may be in contact with the first surface 310, the third surface 330, the fourth surface 340, and the fifth surface 350 respectively. The ends of the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 may be respectively abutted against the surface of the body 322. The part where the second wall 32 contacts the housing 30a may be welded from the outside of the housing 30a (the side away from the electrode assembly 11), that is, the second wall 32 and the housing 30a are integrated by means of side welding. In this welding method, taking the second wall 32 as the bottom wall, the welding mark between the second wall 32 and the housing 30a is located on the side of the outer shell 30.

[0245] In the above solution, there is no inner fillet at the junction of the second wall 32 and the housing 30a. Therefore, during the assembly process or the internal expansion process of the battery cell 10, the risk of interference of the electrode assembly 11 at the junction of the second wall 32 and the housing 30a is small. In this regard, the reliability of the battery cell 10 is high; at the same time, due to the absence of an inner fillet, a bottom support plate may not be provided, thereby increasing the volume energy density of the battery cell 10, and further increasing the volume energy density of the battery device 100.

[0246] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that, Comprising: A housing, with an accommodation cavity formed inside. The housing includes a first wall, a second wall, and a third wall. Along a first direction, the first wall and the third wall are oppositely arranged, the second wall is located between the first wall and the third wall, and the second wall connects the first wall and the third wall; An electrode assembly, disposed in the accommodation cavity; the electrode assembly is a laminated structure, and the first direction is the lamination direction of the electrode assembly; Or, the electrode assembly is a wound structure, the electrode assembly includes a planar region in the middle and corner regions on both sides, and the first direction is the lamination direction of the electrode assembly in the planar region; Electrode terminals, disposed on the housing and electrically connected to the electrode assembly, and the electrode terminals are located on other wall portions of the housing outside the first wall, the second wall, and the third wall; Wherein, the surface of the first wall facing the inside of the accommodation cavity is a first surface, the surface of the second wall facing the inside of the accommodation cavity is a second surface, the first surface and the second surface are directly connected and the connection region forms a first preset angle, the first preset angle is not less than 85° and not greater than 95°.

2. The battery cell according to claim 1, wherein The electrode assembly includes a main body and an insulating film, the insulating film covers at least part of the main body, and the insulating film is in direct contact with the second wall.

3. The battery cell according to claim 1, wherein The first wall and the second wall are formed by welding.

4. The battery cell according to claim 1, wherein The surface of the third wall facing the inside of the accommodation cavity is a third surface, the third surface and the second surface are directly connected and the connection region forms a second preset angle, the second preset angle is not less than 85° and not greater than 95°.

5. The battery cell according to claim 4, wherein The third wall and the second wall are formed by welding.

6. The battery cell according to claim 1, wherein The housing further includes a fourth wall and a fifth wall. Along a second direction, the fourth wall and the fifth wall are opposite to each other, and the first direction and the second direction are perpendicular to each other; The surface of the fourth wall facing the inside of the accommodation cavity is a fourth surface, the fourth surface and the second surface are directly connected and the connection region forms a third preset angle, the third preset angle is not less than 85° and not greater than 95°; and / or, the surface of the fifth wall facing the inside of the accommodation cavity is a fifth surface, the fifth surface and the second surface are directly connected and the connection region forms a fourth preset angle, the fourth preset angle is not less than 85° and not greater than 95°.

7. The battery cell according to claim 6, wherein The fourth wall and the second wall are formed by welding; and / or, the fifth wall and the second wall are formed by welding.

8. The battery cell according to claim 6, wherein The outer shell includes a housing, the housing is an integral structure, the housing includes the first wall, the third wall, the fourth wall, and the fifth wall. Along the thickness direction of the second wall, one end of the housing has a first opening, and the second wall closes the first opening.

9. The battery cell according to claim 8, wherein The outer shell further includes a sixth wall. Along the thickness direction of the second wall, the other end of the housing has a second opening, and the sixth wall closes the second opening.

10. The battery cell according to claim 9, wherein Along the circumferential direction of the outer shell, the opposite ends of the fourth wall are respectively bent on the first wall and the third wall; Along the circumferential direction of the outer shell, the fifth wall includes a first part and a second part. The first part is bent on the first wall, the second part is bent on the third wall, and the first part and the second part are welded and formed.

11. The battery cell according to claim 8, wherein The housing further includes a sixth wall. Along the circumferential direction of the outer shell, the first wall, the third wall, the fourth wall, and the fifth wall surround the edge of the sixth wall. Along the thickness direction of the second wall, the sixth wall and the second wall are opposite to each other.

12. The battery cell according to claim 11, wherein The electrode terminal is disposed on the sixth wall.

13. The battery cell according to claim 6, wherein The first wall, the third wall, the fourth wall, and the fifth wall are separate structures from each other. The opposite ends of the fourth wall along the second direction are respectively welded to the first wall and the third wall, and the opposite ends of the fifth wall along the second direction are respectively welded to the first wall and the third wall.

14. The battery cell according to claim 1, wherein Along the thickness direction of the second wall, the electrode terminal is disposed on the wall of the outer shell that is opposite to the second wall.

15. The battery cell according to claim 1, wherein The electrode terminal is disposed on the wall of the outer shell along the second direction, and the first direction, the second direction, and the thickness direction of the second wall are perpendicular to each other.

16. The battery cell according to claim 15, wherein The electrode terminal includes a first electrode terminal and a second electrode terminal with opposite polarities. The first electrode terminal is disposed on one wall of the outer shell along the second direction, and the second electrode terminal is disposed on the other wall of the outer shell along the second direction.

17. The battery cell according to claim 1, wherein The material of the outer shell is steel, the thickness of the outer shell is not less than 0.075 mm and not more than 0.3 mm.

18. The battery cell according to claim 17, wherein The thickness of the outer shell is not less than 0.15 mm and not more than 0.25 mm.

19. The battery cell according to claim 1, wherein The first wall and the second wall are connected by a first connecting portion, the first surface is in contact with the outer peripheral surface of the second wall, and along the first direction, the first connecting portion is located between the first surface and the outer peripheral surface of the second wall, and a portion of the first connecting portion is located on a side of the second wall away from the accommodating cavity.

20. The battery cell according to claim 19, characterized in that: The first connection portion includes a weld mark formed between the first wall and the second wall.

21. The battery cell according to claim 1, characterized in that: The first wall and the second wall are connected by a first connecting portion. Along the thickness direction of the second wall, a convex portion is formed on the side of the second wall facing the accommodating cavity. The outer peripheral surface of the convex portion contacts the first surface. Along the thickness direction of the second wall, the first connecting portion is located between the end surface of the first wall and the second wall.

22. The battery cell according to claim 21, characterized in that: The first connection portion includes a weld mark formed between the first wall and the second wall.

23. A battery device, characterized in that, A battery cell comprising the battery cell according to any one of claims 1 to 22.

24. An electrical device, characterized in that, The invention comprises the battery cell according to any one of claims 1 to 22 and / or the battery device according to claim 23, wherein the battery cell is used to provide electrical energy.

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