Battery cell, battery device and electric device

Abstract

The invention discloses a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell and an electrode assembly, the shell comprises a shell body and a first wall, the shell body is provided with an opening, and the first wall is connected with the shell body and seals the opening. The electrode assembly is arranged in the shell. Wherein the first wall comprises a body and a connecting part, the connecting part is arranged on the periphery of the body and points to the direction of the first wall along the electrode assembly, and the connecting part protrudes out of the body and is connected with the shell. According to the technical scheme provided by the invention, the reliability of the battery device can be effectively improved.

Description

Technical Field

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

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in 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. Summary of the Invention

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

[0005] In a first aspect, some embodiments of this application provide a battery cell, which includes a housing and an electrode assembly. The housing includes a casing and a first wall, the casing having an opening, and the first wall being connected to the casing and closing the opening. The electrode assembly is disposed within the casing. The first wall includes a body and a connecting portion, the connecting portion being disposed on the outer periphery of the body, protruding from the body along the direction from the electrode assembly to the first wall, and connected to the casing.

[0006] The battery cell provided in the above embodiment has a connecting portion protruding from the outer periphery of the first wall body along the direction of the electrode assembly pointing to the first wall, and the connecting portion is connected to the shell. This increases the distance between the connecting portion between the first wall and the shell and the electrode assembly. Under the condition that the degree of expansion of the electrode assembly is constant, that is, the amount of deformation of the electrode assembly is constant, the deformation angle between the connecting portion between the first wall and the shell and the electrode assembly can be reduced, thereby reducing strain and stress concentration. This can improve the problem of fatigue cracking caused by stress concentration at the connecting portion between the first wall and the shell due to the excessive proximity of the connecting portion between the first wall and the shell and the electrode assembly as the number of charge and discharge cycles of the battery cell increases. This can effectively improve the structural stability of the battery cell shell, making the battery cell more reliable, and thus making the battery device more reliable.

[0007] According to some embodiments of this application, along the thickness direction of the first wall, the connecting portion has a first surface facing the electrode assembly, and the body has a second surface facing the electrode assembly. The first surface protrudes from the second surface by a dimension h, satisfying 0.1mm≤h≤10mm.

[0008] In the above scheme, along the direction of the electrode assembly pointing towards the first wall, on the one hand, by setting the dimension h of the first surface protruding from the second surface to not less than 0.1 mm, the distance between the connection part between the first wall and the shell and the electrode assembly can be effectively increased, thereby improving the problem of cracking at the connection part between the first wall and the shell caused by the expansion of the electrode assembly, resulting in high reliability of the battery cell and thus high reliability of the battery device; on the other hand, by setting the dimension h of the first surface protruding from the second surface to not more than 10 mm, the impact on the overall volume of the battery cell caused by the protruding connection part can be avoided to a certain extent, resulting in a higher volumetric energy density of the battery cell and thus a higher volumetric energy density of the battery device. Therefore, by setting the dimension h of the first surface protruding from the second surface to not less than 0.1 mm and not more than 10 mm, both the reliability of the battery cell and the volumetric energy density can be taken into account.

[0009] According to some embodiments of this application, the condition 0.5mm≤h≤5mm is satisfied.

[0010] In the above scheme, along the direction of the electrode assembly pointing towards the first wall, on the one hand, by setting the dimension h of the first surface protruding from the second surface to not less than 0.5 mm, the distance between the connection part between the first wall and the shell and the electrode assembly can be further increased, thereby effectively improving the problem of cracking at the connection part between the first wall and the shell caused by the expansion of the electrode assembly, resulting in high reliability of the battery cell and thus high reliability of the battery device; on the other hand, by setting the dimension h of the first surface protruding from the second surface to not more than 5 mm, the impact on the overall volume of the battery cell caused by the protruding connection part can be effectively reduced, resulting in a higher volumetric energy density of the battery cell and thus a higher volumetric energy density of the battery device. Therefore, by setting the dimension h of the first surface protruding from the second surface to not less than 0.5 mm and not more than 5 mm, the reliability of the battery cell and the volumetric energy density can be effectively balanced.

[0011] According to some embodiments of this application, the thickness of the connecting portion along the thickness direction of the first wall is t, which satisfies 0.5mm≤t≤10mm.

[0012] In the above scheme, on the one hand, by setting the thickness of the connecting part to not less than 0.5mm, the connecting part can have a certain structural strength, which can protect the internal structure of the battery cell and form a stable connection with the shell, reducing the risk of cracking at the connection between the first wall and the shell under stress. On the other hand, by setting the thickness of the connecting part to not more than 10mm, the impact of the protruding connecting part on the overall volume of the battery cell can be effectively reduced, as well as the risk of interference caused by the protruding connecting part of the battery cell to external structural components, thereby enabling the battery device to have high volumetric energy density and reliability. Therefore, by setting the thickness of the connecting part to not less than 0.5mm and not more than 10mm, the reliability and volumetric energy density of the battery device can be balanced.

[0013] According to some embodiments of this application, the thickness of the connecting portion along the thickness direction of the first wall is t, which satisfies 1mm≤t≤8mm.

[0014] In the above scheme, on the one hand, by setting the thickness of the connecting part to not less than 1mm, the connecting part can have a certain structural strength, which can protect the internal structure of the battery cell and form a stable connection with the shell, reducing the risk of cracking at the connection between the first wall and the shell under stress. On the other hand, by setting the thickness of the connecting part to not more than 8mm, the impact of the protruding connecting part on the overall volume of the battery cell can be effectively reduced, as well as the risk of interference caused by the protruding connecting part of the battery cell to external structural components, thereby enabling the battery device to have high volumetric energy density and reliability. Therefore, by setting the thickness of the connecting part to not less than 1mm and not more than 8mm, the reliability and volumetric energy density of the battery device can be balanced.

[0015] According to some embodiments of this application, the electrode assembly includes an electrode sheet having a flat region. The flat regions are stacked along a first direction, which is perpendicular to the thickness direction of the first wall. Along the first direction, the outermost flat region of the electrode assembly has a third surface facing the first wall in the thickness direction of the first wall. The connecting portion has a first surface facing the electrode assembly along the thickness direction of the first wall. The distance between the third surface and the first surface is H, which satisfies 2mm ≤ H ≤ 20mm.

[0016] In the above scheme, as the number of charge-discharge cycles of a single battery cell increases, the expansion of the flat area of ​​the electrode assembly has a relatively large impact on the connection between the first wall and the casing, especially the flat area of ​​the outermost electrode. To address this, by setting the distance between the third surface of the flat area of ​​the outermost electrode and the first surface of the connection portion to be no less than 2mm, the distance between the expanded portion of the electrode assembly and the connection portion between the first wall and the casing can be increased. This improves the problem of cracking at the connection portion between the first wall and the casing caused by electrode assembly expansion, resulting in high reliability of the single battery cell and consequently, high reliability of the battery device. Simultaneously, by setting the distance between the third surface and the first surface to be no more than 20mm, a certain degree of high volumetric energy density of the single battery cell can be ensured, resulting in a high volumetric energy density of the battery device.

[0017] According to some embodiments of this application, the following conditions are met: 3mm ≤ H ≤ 15mm.

[0018] In the above scheme, by setting the distance between the third surface of the flat area of ​​the outermost electrode and the first surface of the connection part to not less than 3mm, the distance between the part of the electrode assembly that expands and the connection part between the first wall and the shell can be further increased, thereby improving the problem of cracking at the connection part between the first wall and the shell caused by the expansion of the electrode assembly, resulting in high reliability of the battery cell and thus high reliability of the battery device; at the same time, by setting the distance between the third surface and the first surface to not more than 15mm, the space utilization rate inside the battery cell can be effectively improved, resulting in a higher volumetric energy density of the battery cell and a higher volumetric energy density of the battery device.

[0019] According to some embodiments of this application, along the thickness direction of the first wall, the connecting portion has a first surface facing the electrode assembly, the body has a second surface facing the electrode assembly, and along the radial direction of the first wall, the body has a fourth surface, the fourth surface connecting the first surface and the second surface, and the fourth surface being spaced apart from the inner wall surface of the housing.

[0020] In the above scheme, the fourth surface of the main body is spaced apart from the inner wall of the shell, that is, the fourth surface and the inner wall of the shell do not contact each other. On the one hand, this can provide additional space for the internal structure of the battery cell, which can accommodate more electrolyte or reduce the risk of mutual interference between the internal structures of the battery cell. On the other hand, it makes the overall size and mass of the first wall small, reducing the material cost of the battery cell and facilitating the improvement of the mass energy density of the battery cell.

[0021] According to some embodiments of this application, the distance J between the fourth surface and the inner wall surface of the housing along the radial direction of the first wall satisfies 0.1mm≤J≤20mm.

[0022] In the above scheme, by setting the distance between the fourth surface and the inner wall of the housing to not less than 0.1 mm along the radial direction of the first wall, the difficulty of forming the body and connecting parts of the first wall can be effectively reduced (for example, if the first wall is made of aluminum, the body and the connecting parts protruding from the body can be formed simply and efficiently through processes such as stamping or die casting), resulting in high manufacturing efficiency of the battery cell. On the other hand, by setting the distance between the fourth surface and the inner wall of the housing to not more than 20 mm, the risk of affecting the structural strength of the outer shell due to excessive distance between the body and the housing can be reduced, thereby facilitating the setting of other structures on the body of the first wall. For example, the electrode terminals can be stably set on the body, resulting in high reliability of the battery cell and thus high reliability of the battery device.

[0023] According to some embodiments of this application, the condition 0.5mm≤J≤10mm is satisfied.

[0024] In the above scheme, by setting the distance between the fourth surface and the inner wall of the housing to not less than 0.5 mm along the radial direction of the first wall, the difficulty of forming the body and connecting parts of the first wall can be further reduced (for example, if the first wall is made of aluminum, the body and the connecting parts protruding from the body can be formed simply and efficiently through processes such as stamping or die casting), resulting in high manufacturing efficiency of the battery cell; on the other hand, by setting the distance between the fourth surface and the inner wall of the housing to not more than 10 mm, the risk of affecting the structural strength of the outer shell due to excessive distance between the body and the housing can be effectively reduced, thereby facilitating the setting of other structures on the body of the first wall, such as enabling the electrode terminals to be stably set on the body, resulting in high reliability of the battery cell, and thus high reliability of the battery device.

[0025] According to some embodiments of this application, the connecting part is connected to the housing through a first connecting part, the outer peripheral surface of the connecting part is in contact with the inner wall surface of the housing, and the first connecting part is located between the outer peripheral surface of the connecting part and the inner wall surface of the housing.

[0026] In the above solution, the connecting part is connected to the housing through the first joint, and the first joint can be disposed between the outer peripheral surface of the connecting part and the inner wall surface of the housing from the side of the first wall away from the electrode assembly. This reduces the difficulty of connecting the connecting part and the housing, resulting in high manufacturing efficiency of the battery cell and improving the manufacturing efficiency of the battery device.

[0027] According to some embodiments of this application, the first joint includes a first solder mark formed between the joint and the housing.

[0028] In the above scheme, the connecting part and the housing are connected to each other by welding, and the welding direction can be the direction of the first wall pointing to the electrode assembly. Therefore, the connection between the connecting part and the housing is reliable, and the connection between the connecting part and the housing is easy and efficient.

[0029] According to some embodiments of this application, the connecting part is connected to the housing through a second connecting part. A flange is provided on the outer periphery of the connecting part. Along the thickness direction of the first wall, the side of the flange facing the electrode assembly contacts the end face of the housing. The second connecting part is located between the flange and the end face of the housing.

[0030] In the above solution, by setting a flange, the positioning between the connecting part and the end face of the housing can be facilitated, reducing the risk of misalignment during the assembly of the first wall and the housing, effectively improving the assembly efficiency between the first wall and the housing, and thus improving the manufacturing efficiency of the battery cell; at the same time, the second joint connecting the connecting part and the housing is located between the flange and the end face of the housing, so that the second joint can be set from the outside of the battery cell, thus making the formation of the second joint easier and improving the manufacturing efficiency of the battery cell.

[0031] According to some embodiments of this application, the second joint includes a second solder mark formed between the flange and the housing.

[0032] In the above scheme, the connecting part and the shell are connected to each other by welding, and the welding direction can be the side of the battery cell (perpendicular to the first wall). Therefore, the connection between the connecting part and the shell is reliable, and the connection between the connecting part and the shell is easy and efficient.

[0033] According to some embodiments of this application, the connecting part and the body are integrally formed.

[0034] In the above scheme, the first wall is formed into the connecting part and the body through an integral molding process, which makes the first wall structurally strong, thereby making the outer shell structurally stable and reliable, which is conducive to improving the reliability of the battery cell and the battery device.

[0035] According to some embodiments of this application, along the thickness direction of the first wall, the first wall is recessed on the side opposite to the electrode assembly and corresponding to the position of the body to form the body and the connecting portion.

[0036] In the above solution, by recessing the outer side of the first wall corresponding to the body, the inner side of the first wall protrudes, thereby forming the body and the connecting part, which can effectively improve the forming efficiency of the first wall and facilitate the improvement of the battery cell manufacturing efficiency.

[0037] According to some embodiments of this application, the battery cell further includes electrode terminals, which are disposed on the body and electrically connected to the electrode assembly.

[0038] In the above scheme, by setting electrode terminals on the main body, the space where the connection part is located can be utilized in the part where the electrode terminals are located on the outside of the main body, so that the battery cell structure is compact and the volumetric energy density is high.

[0039] According to some embodiments of this application, along the thickness direction of the first wall, the side of the electrode terminal facing away from the electrode assembly is flush with the side of the connection portion facing away from the electrode assembly.

[0040] In the above scheme, by setting the side of the electrode terminal away from the electrode assembly to be flush with the side of the connection part away from the electrode assembly, the electrode terminal can effectively utilize the space where the connection part is located, making the battery cell structure compact and the volumetric energy density high.

[0041] According to some embodiments of this application, along the direction from the first wall to the electrode assembly, the side of the electrode terminal away from the electrode assembly protrudes from the side of the connecting portion away from the electrode assembly; or, along the direction from the electrode assembly to the first wall, the side of the electrode terminal away from the electrode assembly protrudes from the side of the connecting portion away from the electrode assembly.

[0042] In some embodiments of the above scheme, by setting the side of the electrode terminal away from the electrode assembly to protrude from the side of the connecting portion away from the electrode assembly, it is easier to connect the electrode terminal to external structural components, reduce the difficulty of battery device assembly, and improve the manufacturing efficiency of battery device. In some embodiments, by setting the side of the connecting portion away from the electrode assembly to protrude from the side of the electrode terminal away from the electrode assembly, it is possible to reduce the impact of external impact on the electrode terminal structure, resulting in high reliability of the battery cell and thus high reliability of the battery device.

[0043] According to some embodiments of this application, the outer casing is an aluminum casing.

[0044] According to some embodiments of this application, the thickness of the shell is T, which satisfies 0.3mm≤T≤2mm.

[0045] Secondly, some embodiments of this application also provide a battery device, which includes the battery cell provided in the first aspect.

[0046] Thirdly, some embodiments of this application also provide an electrical device, which includes the battery cell provided in the first aspect and / or the battery device provided in the second aspect.

[0047] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a schematic diagram of the vehicle structure in some embodiments of this application;

[0050] Figure 2 This is an exploded perspective view of the battery device in some embodiments of this application;

[0051] Figure 3 These are perspective views of individual battery cells in some embodiments of this application;

[0052] Figure 4 This is an exploded perspective view of the outer casing in some embodiments of this application;

[0053] Figure 5 This is a top view of a battery cell in some embodiments of this application;

[0054] Figure 6 for Figure 5 A sectional view along the AA direction;

[0055] Figure 7 for Figure 6 Enlarged view of point B in the middle;

[0056] Figure 8 This is a schematic diagram of the flat area, shell, and first wall in some embodiments of this application;

[0057] Figure 9 This is a schematic diagram of the first wall and the shell in other embodiments of this application;

[0058] Figure 10 This is a schematic diagram of the first wall and electrode terminals in some embodiments of this application;

[0059] Figure 11 This is a schematic diagram of the first wall and electrode terminals in other embodiments of this application;

[0060] Figure 12 This is a schematic diagram of the first wall and electrode terminals in other embodiments of this application.

[0061] Icons: 1000 - Vehicle; 100 - Battery Unit; 200 - Controller; 300 - Motor; 20 - Housing; 21 - First Housing Body; 22 - Second Housing Body; 10 - Battery Cell; 11 - Housing; 110 - Shell; 111 - First Wall; 1110 - Body; 11100 - Second Surface; 11101 - Fourth Surface; 1111 - Connecting Part; 1112 - Flange; 11110 - First Surface; 1 113-Terminal hole; 1114-Injection hole; 12-Electrode assembly; 12a-Insulating film; 120-Electrode sheet; 1200-Straight area; 1201-Third surface; 121-Separating membrane; 122-Electrode tab; 13-Adapter; 14-Electrode terminal; 15-Pressure relief mechanism; 16-First joint; 17-Second joint; 18-Sealing member; x-First direction; y-Second direction; z-Thickness direction of the first wall. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0063] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0064] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0065] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0066] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0067] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0068] In this application, "multiple" means two or more (including two).

[0069] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0070] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0071] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0072] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0073] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0074] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0075] In some embodiments, the separator is a separator membrane. The separator membrane can be of various types, and any known porous separator membrane with good chemical and mechanical stability can be selected.

[0076] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0077] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0078] In some implementations, the electrode assembly is a stacked structure.

[0079] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0080] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0081] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0082] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0083] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0084] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0085] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0086] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), or composite metal (such as a copper-aluminum composite housing).

[0087] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include, but are not limited to, square battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0088] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.

[0089] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0090] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0091] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0092] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0093] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0094] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0095] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0096] In some embodiments, the battery device may refer to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0097] As an example, the battery device includes a beam assembly and a battery cell assembly. The beam assembly may include mounting beams and suspension beams arranged in a mutually arranged manner. The suspension beams are used to mount and fix the battery cell assembly, and the mounting beams are used to mount the battery to the power-consuming device body so that the battery supplies power to the power-consuming device body. In some embodiments, the beam assembly may be a partial structural component of the housing.

[0098] Battery devices possess outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide applicability, and low self-discharge coefficient, making them an important component of today's new energy development. The development of battery technology must simultaneously consider multiple design factors, such as performance parameters like energy density, cycle life, and discharge capacity. Furthermore, the reliability of the battery device must also be taken into account.

[0099] In related technologies, a battery cell includes a casing and an electrode assembly, with the electrode assembly disposed within the casing. The casing includes an end wall and a housing, with the end wall connected to the housing and sealing the opening of the housing, thus placing the electrode assembly in a closed space. As the number of charge-discharge cycles of the battery cell increases, the electrode assembly expands and acts on the casing. The connection between the housing and the end wall experiences stress concentration, leading to fatigue cracking, which affects the reliability of the battery cell and consequently the reliability of the battery device.

[0100] Based on the above considerations, to improve the problem of fatigue cracking affecting the reliability of the battery cell due to the expansion of the electrode assembly at the connection between the end wall and the housing, some embodiments of this application provide a battery cell including a housing and an electrode assembly. The housing includes a shell and a first wall, the shell having an opening, and the first wall connecting to the shell and closing the opening. The electrode assembly is disposed within the housing. The first wall includes a body and a connecting portion, the connecting portion being disposed on the outer periphery of the body, along the direction from the electrode assembly to the first wall, the connecting portion protruding from the body and connected to the housing.

[0101] The battery cell provided in the above embodiment has a connecting portion protruding from the outer periphery of the first wall body along the direction of the electrode assembly pointing to the first wall, and the connecting portion is connected to the shell. This increases the distance between the connecting portion between the first wall and the shell and the electrode assembly. Under the condition that the degree of expansion of the electrode assembly is constant, that is, the amount of deformation of the electrode assembly is constant, the deformation angle between the connecting portion between the first wall and the shell and the electrode assembly can be reduced, thereby reducing strain and stress concentration. This can improve the problem of fatigue cracking caused by stress concentration at the connecting portion between the first wall and the shell due to the excessive proximity of the connecting portion between the first wall and the shell and the electrode assembly as the number of charge and discharge cycles of the battery cell increases. This can effectively improve the structural stability of the battery cell shell, making the battery cell more reliable, and thus making the battery device more reliable.

[0102] The battery cells disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft.

[0103] This application provides an electrical device that uses a single battery cell or battery assembly as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0104] For ease of explanation, the following embodiments will be described using a vehicle as an example of an electrical device according to an embodiment of this application.

[0105] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle 1000. The battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, it can serve as the operating power source or general power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 controls the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0106] In some embodiments of this application, the battery device 100 can not only serve as the operating power or power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0107] Please refer to Figure 2 , Figure 2 This is an exploded perspective view of the battery device 100 in some embodiments of this application. The battery device 100 includes a housing 20 and battery cells 10, the battery cells 10 being housed within the housing 20.

[0108] The housing 20 provides assembly space for the battery cell 10, and can adopt various structures. In some embodiments, the housing 20 may include a first housing body 21 and a second housing body 22, which overlap each other, and together define an assembly space for accommodating the battery cell 10. The second housing body 22 may be a hollow structure open at one end, and the first housing body 21 may be a plate-like structure, with the first housing body 21 covering the open side of the second housing body 22 so that the first housing body 21 and the second housing body 22 together define the assembly space; alternatively, the first housing body 21 and the second housing body 22 may both be hollow structures open on one side, with the open side of the first housing body 21 covering the open side of the second housing body 22.

[0109] Of course, the box 20 formed by the first box body 21 and the second box body 22 can be of various shapes, such as a cylinder, a cuboid, or a cube. For example, in... Figure 2 In the middle, the shape of box 20 is a cuboid.

[0110] In the battery device 100, there can be one or more battery cells 10 disposed within the housing 20. When there are multiple battery cells 10 disposed within the housing 20, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 10 are connected in both series and parallel configurations. Multiple battery cells 10 can be directly connected in series, in parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 10 is housed within the housing 20. Alternatively, the battery device 100 can also be composed of multiple battery cells 10 first connected in series, in parallel, or in a mixed configuration to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 20.

[0111] In some embodiments, the battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar for connecting multiple battery cells 10 to achieve electrical connection between the multiple battery cells 10.

[0112] For example, the housing 20 is provided with a plurality of battery cell assemblies, each battery cell assembly including 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 busbar. In some embodiments, the plurality of battery cell assemblies can be connected in series with each other through a busbar.

[0113] Each battery cell 10 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 10 can be in the form of a cuboid, cylinder, prism, or other shapes. For example, in... Figure 3 In the middle, the battery cell 10 has a cuboid structure.

[0114] Some embodiments of this application provide a single battery cell 10; please refer to [link to relevant documentation]. Figures 3-7 , Figure 3 This is a perspective view of a battery cell 10 in some embodiments of this application. Figure 4 This is an exploded perspective view of the outer casing 11 in some embodiments of this application. Figure 5 This is a top view of a battery cell 10 in some embodiments of this application. Figure 6 for Figure 5 Sectional view in the middle AA direction. Figure 7 for Figure 6 Enlarged view of point B in the middle.

[0115] The battery cell 10 includes a housing 11 and an electrode assembly 12. The housing 11 includes a shell 110 and a first wall 111. The shell 110 has an opening, and the first wall 111 is connected to the shell 110 and closes the opening. The electrode assembly 12 is disposed inside the housing 11. The first wall 111 includes a body 1110 and a connecting portion 1111. The connecting portion 1111 is disposed on the outer periphery of the body 1110, along the direction from the electrode assembly 12 to the first wall 111, and protrudes from the body 1110 and is connected to the shell 110.

[0116] In some embodiments, the outer casing 11 can also be used to contain an electrolyte, such as an electrolyte solution. The outer casing 11 can have various structural forms, such as a square shell structure, a cylindrical shell structure, or a bag-like structure. The outer casing 11 can also be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0117] In some embodiments, see Figure 3 and Figure 4 The outer casing 11 includes a housing 110 and a first wall 111. The housing 110 has an internal cavity with an opening, meaning the housing 110 is a hollow structure with one open end. The first wall 111 covers the opening of the housing 110 and forms a sealed connection, creating a sealed space for accommodating the electrode assembly 12 and the electrolyte. In some embodiments, the connection between the first wall 111 and the housing 110 is varied, including but not limited to bonding, welding, riveting, or threaded connections. Optionally, the first wall 111 can be the top cover or the bottom wall of the outer casing 11.

[0118] Optionally, there are two first walls 111, and the two opposite ends of the shell 110 are open, that is, they have two opposite openings. One opening can be closed by one of the first walls 111, and the other opening can be closed by the other first wall 111.

[0119] Optionally, the thickness direction z of the first wall can be the height direction of the battery cell 10. In some other embodiments, the thickness direction z of the first wall can be the width direction or the thickness direction of the battery cell 10.

[0120] When assembling the battery cell 10, the electrode assembly 12 can be placed into the housing 110 first, and an electrolyte, such as electrolyte solution, can be filled into the housing 110. Then, the first wall 111 can be placed over the opening of the housing 110 to seal the opening of the housing 110.

[0121] The housing 110 can have various shapes, such as a cylinder or a cuboid. The shape of the housing 110 can be determined according to the specific shape of the electrode assembly 12. For example, if the electrode assembly 12 is a cylindrical structure, then the housing 110 can be a cylindrical structure; if the electrode assembly 12 is a cuboid structure, then the housing 110 can be a cuboid structure. Of course, the first wall 111 can also have various shapes, which can correspond to the shape of the housing 110. For example, in... Figure 3 and Figure 4 In the middle, the shell 110 has a cuboid structure, and correspondingly, the end cap has a rectangular structure.

[0122] The electrode assembly 12 is a component in the battery cell 10 where electrochemical reactions occur. The structure of the electrode assembly 12 can be various. For example, the electrode assembly 12 includes an electrode 120 and a separator. For example, the electrode assembly 12 can be a wound structure formed by winding a positive electrode, a separator and a negative electrode, or a stacked structure formed by arranging a positive electrode, a separator and a negative electrode in layers.

[0123] Optionally, the electrode assembly 12 includes an electrode 120, which has a flat region 1200. The flat regions 1200 of the positive electrode and the flat regions 1200 of the negative electrode are stacked along a first direction x, which is perpendicular to the thickness direction z of the first wall. For example, if the electrode assembly 12 has a stacked structure, all of the electrode 120 can be flat regions 1200, and the positive electrode, separator 121, and negative electrode are stacked along the first direction x. For example, if the electrode assembly 12 has a wound structure, the electrode 120 can include a flat region 1200 and corner regions disposed at both ends of the flat region 1200. The flat regions 1200 of the positive electrode, separator 121, and flat regions 1200 of the negative electrode are stacked along the first direction x, and the corner regions of the positive electrode, separator, and negative electrode are stacked on top of each other.

[0124] To indicate direction, y is used as the second direction in the figure. The second direction y, the first direction x, and the thickness direction z of the first wall are all perpendicular to each other. For example, the thickness direction z of the first wall can be the height direction of the battery cell 10, the first direction can be the thickness square of the battery cell 10, and the second direction y can be the width direction of the battery cell.

[0125] Optionally, the separator is a separator membrane 121, and the main material of the separator membrane 121 can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.

[0126] The electrode assembly 12 has tabs 122 for inputting or outputting the positive or negative electrode of the electrode assembly 12. The tabs 122 are connected to the electrode terminals 14 via adapters 13 to achieve an electrical connection between the electrode assembly 12 and the electrode terminals 14. Optionally, in some embodiments, the tabs 122 are led out from the flat region 1200 of the electrode plate 120. In some embodiments, the tabs 122 are located at one end of the electrode assembly 12 in the thickness direction z of the first wall near the first wall 111; or, the electrode assembly 12 has tabs 122 at two opposite ends in the thickness direction z of the first wall; or, the tabs 122 are located on the side of the electrode assembly 12 along the thickness direction z of the first wall.

[0127] It should be noted that the tabs 122 of the electrode assembly 12 are formed by stacking and connecting the regions of the positive electrode sheet that are not coated with a positive active material layer, or by stacking and connecting the regions of the negative electrode sheet that are not coated with a negative active material layer. If the tabs 122 are used for the positive electrode of the output electrode assembly 12, then the tabs 122 are formed by stacking and connecting the regions of the positive electrode sheet that are not coated with a positive active material layer; if the tabs 122 are used for the negative electrode of the output electrode assembly 12, then the tabs 122 are formed by stacking and connecting the regions of the negative electrode sheet that are not coated with a negative active material layer.

[0128] Optionally, the electrode assembly 12 housed within the housing 11 can be one or more. For example, in... Figure 3 In this embodiment, the outer casing 11 of the battery cell 10 is provided with two electrode assemblies 12, which are stacked along their thickness direction. That is, the two electrode assemblies 12 are stacked along the thickness direction of the battery cell 10. Of course, in other embodiments, the electrode assemblies 12 housed in the outer casing 11 can be one, three, four, five, six, seven or eight, etc.

[0129] In some embodiments, the outer periphery of the electrode assembly may be covered with an insulating film 12a, such as a blue film.

[0130] In some embodiments of this application, the first wall 111 includes a body 1110 and a connecting portion 1111. The body 1110 is the main structure of the first wall 111. Exemplarily, along the thickness direction z of the first wall, the orthographic projection of the body 1110 can at least partially overlap with the orthographic projection of the electrode assembly 12. The connecting portion 1111 is a part disposed on the outer periphery of the body 1110 for connecting with the housing 110 to close the opening of the housing 110.

[0131] The connecting part 1111 is disposed on the outer periphery of the body 1110. It can be understood that the connecting part is located on the outer periphery of the body 1110. The connecting part 1111 can be a ring structure that can surround the body 1110; or the connecting part 1111 can be an intermittent ring structure that is intermittently disposed on the outer periphery of the body 1110.

[0132] Optionally, along the thickness direction z of the first wall, the orthographic projection of the connecting portion 1111 does not overlap with the orthographic projection of the electrode assembly 12.

[0133] Optionally, along the thickness direction z of the first wall, the orthographic projection of the connecting portion 1111 overlaps with the orthographic projection of the electrode assembly 12. For example, the orthographic projection of the connecting portion 1111 can overlap with the edge of the orthographic projection of the electrode assembly 12.

[0134] In some embodiments, the body 1110 is provided with electrode terminals 14, which are electrically connected to the tabs 122 of the electrode assembly 12. In some embodiments, electrode terminals 14 with opposite polarities are respectively disposed on the first wall 111 and the wall portion of the housing 11 opposite to the first wall 111. In other embodiments, the electrode terminals 14 are disposed on the wall portion of the housing 11 opposite to the first wall 111. Some embodiments of this application are illustrated by taking the electrode terminals 14 disposed on the body 1110 of the first wall 111 as an example.

[0135] The electrode terminal 14 serves to output or input electrical energy of the battery cell 10. One end of the electrode terminal 14 is used to connect to the tab 122 of the electrode assembly 12, and the other end is used to connect to the busbar component to realize the input or output of electrical energy of the battery cell 10.

[0136] For example, the electrode terminal 14 can be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. Of course, in some embodiments, the electrode terminal 14 can also be a composite material, that is, the electrode terminal 14 is formed by connecting two different metal materials, such as by hot pressing or cold pressing.

[0137] The first wall 111 has a terminal hole 1113 on its body 1110. The terminal hole 1113 extends through both sides of the first wall 111 along the thickness direction z. The electrode terminal 14 is inserted into the terminal hole 1113 along the thickness direction z of the first wall, so that part of the electrode terminal 14 is located in the terminal hole 1113. This allows the electrode terminal 14 to be connected to the electrode assembly 12 located inside the housing 11, as well as to the busbar located outside the housing 11, so as to realize the input or output of electrical energy of the battery cell 10.

[0138] The assembly relationship between the electrode terminal 14 and the body 1110 of the first wall 111 is varied. For example, the electrode terminal 14 can be riveted to the body 1110. For instance, the electrode terminal 14 may consist of two riveted parts that clamp the body 1110. Alternatively, the electrode terminal 14 and the body 1110 can be connected by other structural components. For example, the electrode terminal 14 may pass through a terminal hole 1113, and a pressure ring may be welded to the body 1110. The pressure ring and the body 1110 together clamp a portion of the electrode terminal 14 in the thickness direction z of the first wall, thereby assembling the electrode terminal 14.

[0139] Optionally, the electrode terminal 14 can be directly connected to the tab 122 of the electrode assembly 12, such as by welding or abutting, or it can be indirectly connected to the tab 122 of the electrode assembly 12 through other components. Similarly, the connection structure between the electrode terminal 14 and the bus component can also be various, such as welding, abutting, or snap-fitting.

[0140] In some embodiments, see Figure 3 and Figure 6 As shown, the battery cell 10 may further include an adapter 13, which is disposed within the housing 11. The adapter 13 connects the electrode terminal 14 and the tab 122 of the electrode assembly 12 to achieve an electrical connection between the electrode assembly 12 and the electrode terminal 14. Optionally, along the thickness direction z of the first wall, the orthographic projection of the adapter 13 is covered by the orthographic projection of the body 1110. The adapter 13 can be made of various materials; for example, the electrode terminal 14 can be made of copper, iron, aluminum, steel, aluminum alloy, etc. Of course, in some embodiments, the adapter 13 can also be a composite material, that is, the adapter 13 is formed by connecting two different metal materials, such as by hot pressing or cold pressing.

[0141] In some embodiments, see Figures 3-5 As shown, the battery cell 10 may further include a pressure relief mechanism 15, which is disposed on the body 1110. The pressure relief mechanism 15 is used to release the internal pressure of the battery cell 10 when the internal pressure or temperature reaches a predetermined value. Optionally, the pressure relief mechanism 15 and the body 1110 can be integrally formed or separately disposed. If the pressure relief mechanism 15 and the body 1110 are separate structures, the pressure relief mechanism 15 can be connected to the body 1110 by welding or other means. For example, the body 1110 has a pressure relief hole, and the pressure relief mechanism 15 closes the pressure relief hole. Correspondingly, the pressure relief mechanism 15 can be a pressure relief component such as an explosion-proof valve, explosion-proof disc, air valve, pressure relief valve, or safety valve. If the pressure relief mechanism 15 and the body 1110 are integrally formed, the pressure relief mechanism 15 is a region on the body 1110 with a weak structure, such as a region on the body 1110 with a groove.

[0142] In some embodiments, see Figures 3-5 As shown, the body 1110 may also be provided with an injection hole 1114, which is used to inject electrolyte, such as electrolyte solution, into the battery cell 10. In some embodiments, after injection, the injection hole 1114 can be sealed by a sealing member 18, which may include a plastic nail, an aluminum nail, or other structural components.

[0143] In particular, along the direction of the electrode assembly 12 pointing to the first wall 111, the connecting part 1111 protrudes from the body 1110, that is, the connecting part 1111 is further away from the electrode assembly 12 relative to the body 1110.

[0144] In some embodiments, the inner side of the connecting portion 1111 may be parallel to the inner side of the body 1110, that is, the connecting portion 1111 and the body 1110 may be regarded as two parallel plate-shaped structural members. In some embodiments, the inner side of the connecting portion 1111 may be inclined to the inner side of the body 1110, that is, the connecting portion 1111 and the body 1110 may be regarded as two inclined plate-shaped structural members.

[0145] In some embodiments, the connecting portion 1111 may protrude entirely from the body 1110 or may protrude partially from the body 1110. Optionally, the connecting portion 1111 and the body 1110 may be directly connected or indirectly connected.

[0146] Exemplarily, a transition portion is provided between the connecting portion 1111 and the body 1110, and the connecting portion 1111 smoothly transitions to the outer periphery of the body 1110 through the transition portion. Exemplarily, the connecting portion 1111 is directly disposed on the outer side surface of the body 1110, and the connecting portion 1111 extends outward in the radial direction of the first wall 111.

[0147] In some embodiments, the connecting portion 1111 and the body 1110 can be an integrally formed structure. For example, along the thickness direction z of the first wall, the portion on the outer side of the first wall 111 and located in the middle of the first wall 111 is recessed toward the electrode assembly 12 to form a protrusion on the inner side of the first wall 111. The protrusion is the body 1110, and the edge of the first wall 111 and the portion that is not recessed forms the connecting portion 1111.

[0148] In other embodiments, the connecting portion 1111 and the body 1110 can be separate structures, connected by bonding, welding, riveting, threading, or other means. Exemplarily, the connecting portion 1111 is an annular structure welded to the edge of the body 1110. In some embodiments where the connecting portion 1111 and the body 1110 can be separate structures, the materials of the connecting portion 1111 and the body 1110 can be the same or different. Exemplarily, both the connecting portion 1111 and the body 1110 are made of aluminum; or the connecting portion 1111 is made of aluminum and the body 1110 is made of plastic.

[0149] The phrase “connecting part 1111 protrudes from the body 1110 and is connected to the housing 110” can be understood as the first wall 111 being connected to the housing 110 through the connecting part 1111. That is, the connecting part 1111 between the connecting part 1111 and the housing 110 is the connecting part 1111 between the first wall 111 and the housing 110. This connecting part 1111 is further away from the electrode assembly 12 relative to the body 1110.

[0150] In some embodiments, the connection relationship between the connecting part 1111 and the housing 110 is diverse, including but not limited to bonding, welding, riveting, threaded connection or other connection methods.

[0151] The battery cell 10 provided in the above embodiment has a connecting portion 1111 protruding from the outer periphery of the body 1110 of the first wall 111 along the direction of the electrode assembly 12 pointing towards the first wall 111. This connecting portion 1111 is connected to the housing 110, which increases the distance between the connecting portion 1111 between the first wall 111 and the housing 110 and the electrode assembly 12. Under the condition that the degree of expansion of the electrode assembly 12 is constant, i.e., the amount of deformation of the electrode assembly 12 is constant, the distance between the connecting portion 1111 between the first wall 111 and the housing 110 and the electrode assembly 12 is kept small. The reduced deformation angle leads to reduced strain and decreased stress concentration. This mitigates the problem of fatigue cracking caused by stress concentration at the connection between the first wall 111 and the shell 110 due to the close proximity of the connection 1111 between the battery cell 10 and the electrode assembly 12 as the number of charge-discharge cycles increases. This effectively improves the structural stability of the battery cell 10 shell 11, resulting in high reliability of the battery cell 10 and consequently, high reliability of the battery device 100.

[0152] According to some embodiments of this application, please refer to Figure 7Along the thickness direction z of the first wall, the connecting part 1111 has a first surface 11110 facing the electrode assembly 12, and the body 1110 has a second surface 11100 facing the electrode assembly 12. The first surface 11110 protrudes from the second surface 11100 by a dimension h, which satisfies 0.1mm≤h≤10mm.

[0153] In some embodiments, the first surface 11110 can be the inner side surface of the connecting portion 1111, and the second surface 11100 can be the inner side surface of the body 1110. Along the thickness direction z of the first wall, the dimension by which the first surface 11110 protrudes from the second surface 11100 can be understood as the dimension by which the connecting portion 1111 protrudes from the body 1110. See also... Figure 7 The first surface 11110 protrudes from the second surface 11100 by a dimension h, and the value of h can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm...9.7mm, 9.8mm, 9.9mm, 10mm or any value between two adjacent values.

[0154] In the above scheme, along the direction from the electrode assembly 12 to the first wall 111, on the one hand, by setting the dimension h of the first surface 11110 protruding from the second surface 11100 to not less than 0.1mm, the distance between the connection portion 1111 between the first wall 111 and the housing 110 and the electrode assembly 12 can be effectively increased, thereby improving the problem of cracking at the connection portion 1111 between the first wall 111 and the housing 110 caused by the expansion of the electrode assembly 12, resulting in high reliability of the battery cell 10, and thus high reliability of the battery device 100; on the other hand, through By setting the dimension h of the first surface 11110 protruding from the second surface 11100 to no more than 10 mm, the impact on the overall volume of the battery cell 10 caused by the protruding connecting part 1111 can be avoided to a certain extent, so that the battery cell 10 has a higher volumetric energy density, and thus the battery device 100 has a higher volumetric energy density. In this regard, by setting the dimension h of the first surface 11110 protruding from the second surface 11100 to no less than 0.1 mm and no more than 10 mm, the reliability and volumetric energy density of the battery cell 10 can be balanced.

[0155] In some other embodiments, the dimension h of the first surface 11110 protruding from the second surface 11100 can also be a value greater than 0 and less than 0.1 mm, which can improve the problem of cracking at the connection 1111 between the first wall 111 and the housing 110 caused by the expansion of the electrode assembly 12 to a certain extent. In some other embodiments, with the development of battery technology, the size of the battery cell 10 tends to be larger and larger. Under the condition of a larger battery cell 10, the dimension h of the first surface 11110 protruding from the second surface 11100 can also be greater than 10 mm.

[0156] According to some embodiments of this application, the condition 0.5mm≤h≤5mm is satisfied.

[0157] Please see Figure 7 The first surface 11110 protrudes from the second surface 11100 by a dimension h, and the value of h can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm...4.7mm, 4.8mm, 4.9mm, 5mm or any value between two adjacent values.

[0158] In the above scheme, along the direction from the electrode assembly 12 to the first wall 111, on the one hand, by setting the dimension h of the first surface 11110 protruding from the second surface 11100 to not less than 0.5mm, the distance between the connection portion 1111 between the first wall 111 and the housing 110 and the electrode assembly 12 can be further increased, thereby effectively improving the problem of cracking at the connection portion 1111 between the first wall 111 and the housing 110 caused by the expansion of the electrode assembly 12, resulting in high reliability of the battery cell 10, and thus high reliability of the battery device 100; on the other hand, through By setting the dimension h of the first surface 11110 protruding from the second surface 11100 to no more than 5 mm, the impact on the overall volume of the battery cell 10 caused by the protruding connecting part 1111 can be effectively reduced, so that the battery cell 10 has a higher volumetric energy density, and thus the battery device 100 has a higher volumetric energy density. In this regard, by setting the dimension h of the first surface 11110 protruding from the second surface 11100 to no less than 0.5 mm and no more than 5 mm, the reliability and volumetric energy density of the battery cell 10 can be effectively balanced.

[0159] According to some embodiments of this application, the thickness of the connecting portion 1111 is t along the thickness direction z of the first wall, satisfying 0.5mm≤t≤10mm.

[0160] like Figure 7 Along the thickness direction z of the first wall, the thickness of the connecting part 1111 is t, and the value of t can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm...9.7mm, 9.8mm, 9.9mm, 10mm or any value between two adjacent values.

[0161] Optionally, the thickness of the body 1110 along the thickness direction z of the first wall can be equal to the thickness of the connecting portion 1111. Optionally, the thickness of the body 1110 along the thickness direction z of the first wall can be different from the thickness of the connecting portion 1111.

[0162] In the above scheme, on the one hand, by setting the thickness of the connecting part 1111 to not less than 0.5mm, the connecting part 1111 can have a certain structural strength, which can protect the internal structure of the battery cell 10 and form a stable connection with the shell 110, reducing the risk of cracking of the connecting part 1111 between the first wall 111 and the shell 110 under stress; on the other hand, by setting the thickness of the connecting part 1111 to not more than 10mm, the impact of the protruding connecting part 1111 on the overall volume of the battery cell 10 can be effectively reduced, as well as the risk of interference caused by the protruding connecting part 1111 of the battery cell 10 to external structural components, thereby enabling the battery device 100 to have a high volumetric energy density and reliability. Therefore, by setting the thickness of the connecting part 1111 to not less than 0.5mm and not more than 10mm, the reliability and volumetric energy density of the battery device 100 can be balanced.

[0163] In some other embodiments, the thickness t of the connecting portion 1111 can also be a value greater than 0 and less than 0.5 mm. In some other embodiments, with the development of battery technology, the size of the battery cell 10 tends to be larger and larger. Under the condition of a larger battery cell 10, the thickness t of the connecting portion 1111 may also be greater than 10 mm.

[0164] According to some embodiments of this application, the thickness of the connecting portion 1111 is t along the thickness direction z of the first wall, satisfying 1mm≤t≤8mm.

[0165] like Figure 7 Along the thickness direction z of the first wall, the thickness of the connecting part 1111 is t, and the value of t can be 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm...7.7mm, 7.8mm, 7.9mm, 8mm or any value between two adjacent values.

[0166] In the above scheme, on the one hand, by setting the thickness of the connecting part 1111 to not less than 1mm, the connecting part 1111 can have a certain structural strength, which can protect the internal structure of the battery cell 10 and form a stable connection with the shell 110, reducing the risk of cracking of the connecting part 1111 between the first wall 111 and the shell 110 under stress; on the other hand, by setting the thickness of the connecting part 1111 to not more than 8mm, the impact of the protruding connecting part 1111 on the overall volume of the battery cell 10 can be effectively reduced, as well as the risk of interference caused by the protruding connecting part 1111 of the battery cell 10 to external structural components, thereby enabling the battery device 100 to have a high volumetric energy density and reliability. Therefore, by setting the thickness of the connecting part 1111 to not less than 1mm and not more than 8mm, the reliability and volumetric energy density of the battery device 100 can be balanced.

[0167] According to some embodiments of this application, please refer to Figure 3 and Figure 8 , Figure 8 This is a schematic diagram of the flat area 1200, the housing 110, and the first wall 111 in some embodiments of this application.

[0168] The electrode assembly 12 includes an electrode sheet 120, which has a flat region 1200. The flat regions 1200 are stacked along a first direction x, which is perpendicular to the thickness direction z of the first wall. Along the first direction x, the outermost flat region 1200 of the electrode assembly 12 has a third surface 1201 facing the first wall 111 in the thickness direction z of the first wall. The connecting portion 1111 has a first surface 11110 facing the electrode assembly 12 along the thickness direction z of the first wall. The distance between the third surface 1201 and the first surface 11110 is H, which satisfies 2mm ≤ H ≤ 20mm.

[0169] In some embodiments, the electrode assembly 12 includes an electrode sheet 120, which has a flat region 1200. The flat region 1200 can be understood as the electrode sheet 120 being flat in the flat region 1200. The electrode sheet 120 includes a positive electrode sheet and a negative electrode sheet. The flat regions 1200 of the positive electrode sheet and the flat regions 1200 of the negative electrode sheet are stacked along a first direction x, which is perpendicular to the thickness direction z of the first wall. A separator 121 is disposed between the positive electrode sheet and the negative electrode sheet. Please refer to [link to relevant documentation]. Figure 8 In some embodiments, the size of the separator 121 along the thickness direction z of the first wall can be larger than the size of the positive electrode or the size of the negative electrode.

[0170] Along the first direction x, the outermost flat region 1200 of the electrode assembly 12 can be the flat region 1200 of the negative electrode or the flat region 1200 of the positive electrode.

[0171] Optionally, along the thickness direction z of the first wall, the size of the outermost flat region 1200 of the electrode assembly 12 can be smaller than the size of the flat regions 1200 of other layers. For example, as shown in... Figure 8 As shown, the end of the outermost straight region 1200 is lower than the ends of the straight regions 1200 in other layers.

[0172] Optionally, along the thickness direction z of the first wall, the size of the outermost flat region 1200 of the electrode assembly 12 can be equal to or greater than the size of the flat regions 1200 of the other layers.

[0173] The third surface 1201 is the surface of the flat area 1200 of the outermost electrode 120 facing the first wall 111. Along the direction of the electrode assembly 12 pointing to the first wall 111, the first surface 11110 of the connecting part 1111 is located on the third surface 1201, and the distance between the two is H. The value of H can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm...18mm, 19mm, 20mm or any value between two adjacent values.

[0174] In the above scheme, as the number of charge and discharge cycles of the battery cell 10 increases, the expansion of the flat area 1200 of the electrode 120 of the electrode assembly 12 has a relatively large impact on the connection 1111 between the first wall 111 and the housing 110, especially the flat area 1200 of the outermost electrode 120. To address this, by setting the distance between the third surface 1201 of the flat region 1200 of the outermost electrode 120 and the first surface of the connecting portion 1111 to be no less than 2mm, the distance between the part of the electrode assembly 12 that expands and the connecting portion 1111 between the first wall 111 and the housing 110 can be increased. This improves the problem of cracking at the connecting portion 1111 between the first wall 111 and the housing 110 caused by the expansion of the electrode assembly 12, resulting in high reliability of the battery cell 10 and thus high reliability of the battery device 100. At the same time, by setting the distance between the third surface 1201 and the first surface 11110 to be no more than 20mm, the battery cell 10 can be guaranteed to have a high volumetric energy density to a certain extent, resulting in a high volumetric energy density of the battery device 100.

[0175] According to some embodiments of this application, the following conditions are met: 3mm ≤ H ≤ 15mm.

[0176] The distance H between the first surface 11110 and the third surface 1201 can be 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm or any value between two adjacent values.

[0177] In the above scheme, by setting the distance between the third surface 1201 of the flat area 1200 of the outermost electrode 120 and the first surface of the connecting portion 1111 to be not less than 3mm, the distance between the part of the electrode assembly 12 that expands and the connecting portion 1111 between the first wall 111 and the housing 110 can be further increased, thereby improving the problem of cracking at the connecting portion 1111 between the first wall 111 and the housing 110 caused by the expansion of the electrode assembly 12, making the battery cell 10 highly reliable, and thus making the battery device 100 highly reliable; at the same time, by setting the distance between the third surface 1201 and the first surface 11110 to be not greater than 15mm, the space utilization rate inside the battery cell 10 can be effectively improved, making the battery cell 10 have a higher volumetric energy density, and thus making the battery device 100 have a higher volumetric energy density.

[0178] According to some embodiments of this application, along the thickness direction z of the first wall, the connecting portion 1111 has a first surface 11110 facing the electrode assembly 12, the body 1110 has a second surface 11100 facing the electrode assembly 12, and along the radial direction of the first wall 111, the body 1110 has a fourth surface 11101, the fourth surface 11101 connects the first surface 11110 and the second surface 11100, and the fourth surface 11101 is spaced apart from the inner wall surface of the housing 110.

[0179] In some embodiments, the radial direction of the first wall 111 may be perpendicular to the axial direction of the first wall 111, and the axial direction of the first wall 111 may be parallel to the thickness direction z of the first wall.

[0180] The fourth surface 11101 can be the outer peripheral surface of the body 1110. The fourth surface 11101 can connect the second surface 11100 and the first surface 11110. Please refer to [link / reference]. Figure 7 or Figure 8 The fourth surface 11101 and the inner wall surface of the shell 110 are spaced apart from each other, and there is a distance between them.

[0181] In the above scheme, the fourth surface 11101 of the body 1110 is spaced apart from the inner wall surface of the shell 110, that is, the fourth surface 11101 and the inner wall surface of the shell 110 do not contact each other. On the one hand, it can provide additional space for the internal structure of the battery cell 10, which can accommodate more electrolyte or reduce the risk of mutual interference between the internal structures of the battery cell 10. On the other hand, it makes the overall size and weight of the first wall 111 small, reducing the material cost of the battery cell 10 and facilitating the improvement of the mass energy density of the battery cell 10.

[0182] According to some embodiments of this application, the distance between the fourth surface 11101 and the inner wall surface of the housing 110 along the radial direction of the first wall 111 is J, which satisfies 0.1mm≤J≤20mm.

[0183] In some embodiments, see Figure 7 Along the radial direction of the first wall 111, the distance J between the fourth surface 11101 and the inner wall surface of the shell 110 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm...19.7mm, 19.8mm, 19.9mm, 20mm or any value between two adjacent values.

[0184] In the above scheme, by setting the distance between the fourth surface 11101 and the inner wall of the housing 110 to not less than 0.1 mm along the radial direction of the first wall 111, the difficulty of forming the body 1110 and the connecting part 1111 of the first wall 111 can be effectively reduced (for example, if the first wall 111 is made of aluminum, the body 1110 and the connecting part 1111 protruding from the body 1110 can be formed simply and efficiently through processes such as stamping or die casting), resulting in high manufacturing efficiency of the battery cell 10. On the other hand, by setting the distance between the fourth surface 11101 and the inner wall of the housing 110 to not more than 20 mm, the risk of affecting the structural strength of the housing 11 due to excessive distance between the body 1110 and the housing 110 can be reduced, thereby facilitating the setting of other structures on the body 1110 of the first wall 111. For example, the electrode terminal 14 can be stably set on the body 1110, resulting in high reliability of the battery cell 10, and thus high reliability of the battery device 100.

[0185] In other embodiments, the value of the distance J between the fourth surface 11101 and the inner wall surface of the housing 110 is not limited. The value of J can be less than 0.1 mm or greater than 20 mm.

[0186] According to some embodiments of this application, the condition 0.5mm≤J≤10mm is satisfied.

[0187] In some embodiments, see Figure 7 Along the radial direction of the first wall 111, the distance J between the fourth surface 11101 and the inner wall surface of the shell 110 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm...9.7mm, 9.8mm, 9.9mm, 10mm or any value between two adjacent values.

[0188] In the above scheme, by setting the distance between the fourth surface 11101 and the inner wall of the housing 110 to not less than 0.5 mm along the radial direction of the first wall 111, the difficulty of forming the body 1110 and the connecting part 1111 of the first wall 111 can be further reduced (for example, if the first wall 111 is made of aluminum, the body 1110 and the connecting part 1111 protruding from the body 1110 can be formed simply and efficiently through processes such as stamping or die casting), resulting in high manufacturing efficiency of the battery cell 10. On the other hand, by setting the distance between the fourth surface 11101 and the inner wall of the housing 110 to not more than 10 mm, the risk of affecting the structural strength of the housing 11 due to excessive distance between the body 1110 and the housing 110 can be effectively reduced, thereby facilitating the setting of other structures on the body 1110 of the first wall 111. For example, the electrode terminal 14 can be stably set on the body 1110, resulting in high reliability of the battery cell 10, and thus high reliability of the battery device 100.

[0189] According to some embodiments of this application, please refer to Figure 7 The connecting part 1111 is connected to the housing 110 through the first connecting part 16. The outer peripheral surface of the connecting part 1111 is in contact with the inner wall surface of the housing 110. The first connecting part 16 is located between the outer peripheral surface of the connecting part 1111 and the inner wall surface of the housing 110.

[0190] The outer peripheral surface of the connecting part 1111 faces the inner wall surface of the housing 110, and the outer peripheral surface of the connecting part 1111 can contact the inner wall surface of the housing 110. "The outer peripheral surface of the connecting part 1111 contacts the inner wall surface of the housing 110" can be understood as the outer diameter of the first wall 111 being approximately the same as the size of the opening of the housing 110, so that the outer peripheral surface of the connecting part 1111 can contact the interior of the housing 110.

[0191] In some embodiments, along the height direction of the first wall 111, the side of the connection portion 1111 opposite to the electrode assembly 12 is substantially flush with or flush with the end face of the housing 110.

[0192] In some embodiments, the first joint 16 is a portion connecting the housing 110 and the connecting portion 1111. The first joint 16 can be a structure formed by welding, bonding, riveting, or threaded connection. Exemplarily, the first joint 16 is a weld mark located between the housing 110 and the connecting portion 1111, and the weld mark is annular along the circumference of the connecting portion 1111. Exemplarily, the first joint 16 is an adhesive structure located between the housing 110 and the connecting portion 1111, such as an adhesive layer formed after glue dries.

[0193] The function of the first joint 16 may include connecting and fastening the outer peripheral surface of the connecting part 1111 to the inner wall surface of the housing 110.

[0194] In the above scheme, the connecting part 1111 is connected to the housing 110 through the first connecting part 16, and the first connecting part 16 can be disposed between the outer peripheral surface of the connecting part 1111 and the inner wall surface of the housing 110 from the side of the first wall 111 away from the electrode assembly 12. This can reduce the difficulty of connecting the connecting part 1111 and the housing 110 to each other, making the manufacturing efficiency of the battery cell 10 high and improving the manufacturing efficiency of the battery device 100.

[0195] According to some embodiments of this application, the first joint 16 includes a first solder mark formed between the connecting portion 1111 and the housing 110.

[0196] In some embodiments, the first joint 16 may be a first weld mark formed by welding the connecting portion 1111 and the housing 110 together. See also Figure 7 The first joint 16 is formed on one side of the housing 11 along the thickness direction z of the first wall. Exemplarily, the welding equipment can weld the portion between the outer peripheral surface of the connection 1111 and the inner wall surface of the housing 110 along the direction of the first wall 111 pointing towards the electrode assembly 12, so as to form a first weld mark between the outer peripheral surface of the connection 1111 and the inner wall surface of the housing 110.

[0197] In the above scheme, the connecting part 1111 and the housing 110 are connected to each other by welding, and the welding direction can be the direction of the first wall 111 pointing to the electrode assembly 12. Therefore, the connection between the connecting part 1111 and the housing 110 is reliable, and the connection between the connecting part 1111 and the housing 110 is easy and efficient.

[0198] According to other embodiments of this application, please refer to Figure 9 , Figure 9 This is a schematic diagram of the first wall 111 and the housing 110 in other embodiments of this application.

[0199] The connecting part 1111 is connected to the housing 110 through the second connecting part 17. A flange 1112 is provided on the outer periphery of the connecting part 1111. Along the thickness direction z of the first wall, the side of the flange 1112 facing the electrode assembly 12 contacts the end face of the housing 110. The second connecting part 17 is located between the flange 1112 and the end face of the housing 110.

[0200] In some embodiments, a flange 1112 is provided on the outer periphery of the connecting portion 1111, and the flange 1112 extends radially outward along the first wall 111. Along the thickness direction z of the first wall, the side of the flange 1112 facing the electrode assembly 12 contacts the end face of the housing 110.

[0201] In some embodiments, the outer periphery of the connecting portion 1111 may contact the inner wall surface of the housing 110. In other embodiments, a gap may exist between the outer periphery of the connecting portion 1111 and the inner wall surface of the housing 110.

[0202] The second joint 17 is the portion connecting the housing 110 and the connecting portion 1111. The second joint 17 can be a welded structure, an adhesive structure, a riveted structure, or a threaded connection structure. Exemplarily, the second joint 17 is a weld mark located between the end face of the housing 110 and the flange 1112, and the weld mark is annular along the circumference of the connecting portion 1111. Exemplarily, the second joint 17 is an adhesive structure located between the housing 110 and the flange 1112, such as an adhesive layer formed after glue dries.

[0203] The function of the second joint 17 may include connecting and fastening the flange 1112 to the end face of the housing 110.

[0204] In the above solution, by setting the flange 1112, the positioning between the connecting part 1111 and the end face of the housing 110 can be facilitated, reducing the risk of misalignment during the assembly of the first wall 111 and the housing 110, effectively improving the assembly efficiency between the first wall 111 and the housing 110, and thus improving the manufacturing efficiency of the battery cell 10; at the same time, the second joint 17 connecting the connecting part 1111 and the housing 110 is located between the flange 1112 and the end face of the housing 110, so that the second joint 17 can be set from the outside of the battery cell 10, thereby reducing the difficulty of forming the second joint 17 and improving the manufacturing efficiency of the battery cell 10.

[0205] According to some embodiments of this application, please refer to Figure 9 The second joint 17 includes a second solder mark formed between the flange 1112 and the housing 110.

[0206] In some embodiments, the second joint 17 may be a second weld mark formed by welding the connecting portion 1111 and the housing 110 together. See also Figure 9 The second joint 17 is formed on the side of the housing 11. Exemplarily, the welding equipment can weld the portion between the end faces of the flange 1112 and the housing 110 along the first direction x to form a second weld mark between the end faces of the flange 1112 and the housing 110.

[0207] In the above scheme, the connecting part 1111 and the housing 110 are connected to each other by welding, and the welding direction can be the side of the battery cell 10 (perpendicular to the first wall 111). Therefore, the connection between the connecting part 1111 and the housing 110 is reliable, and the connection between the connecting part 1111 and the housing 110 is easy and efficient.

[0208] According to some embodiments of this application, the connecting part 1111 and the body 1110 are integrally formed.

[0209] In some embodiments, the first wall 111 is an integrally formed structure, and during the forming process, a connecting portion 1111 and a body 1110 with mutual concave and convex shapes are formed. For example, the first wall 111 is made of aluminum, and the connecting portion 1111 and the body 1110 with mutual concave and convex shapes are formed by extruding or stamping the aluminum plate.

[0210] In the above scheme, the first wall 111 is formed into the connecting part 1111 and the body 1110 through an integral molding process, which makes the first wall 111 structurally strong, thereby making the structure of the outer shell 11 stable and reliable, which is conducive to improving the reliability of the battery cell 10 and the battery device 100.

[0211] In some other embodiments, the connecting part 1111 and the body 1110 are separate structures, and the two are connected by welding, bonding, riveting or other connection methods.

[0212] According to some embodiments of this application, along the thickness direction z of the first wall, the first wall 111 is recessed on the side opposite to the electrode assembly 12 and corresponding to the position of the body 1110, so as to form the body 1110 and the connecting portion 1111.

[0213] In some embodiments, the outer side of the first wall 111 is recessed in the direction of the electrode assembly 12 corresponding to the portion of the body 1110, so that a protrusion from the body 1110 is formed on the side of the first wall 111 facing the electrode assembly 12, and a protruding connecting portion 1111 is formed on the side of the first wall 111 away from the electrode assembly 12. The connecting portion 1111 may be arranged around the body 1110.

[0214] In the above solution, by recessing the outer side of the first wall 111 corresponding to the body 1110, the inner side of the first wall 111 protrudes, thereby forming the body 1110 and the connecting part 1111, which can effectively improve the forming efficiency of the first wall 111 and facilitate the improvement of the manufacturing efficiency of the battery cell 10.

[0215] According to some embodiments of this application, the battery cell 10 further includes an electrode terminal 14, which is disposed on the body 1110 and electrically connected to the electrode assembly 12.

[0216] Electrode terminals 14 are disposed on the body 1110. A portion of the electrode terminals 14 is located on the outside of the body 1110 and a portion is located on the inside of the body 1110. The portion located on the inside of the body 1110 can be directly or indirectly connected to the tab 122, and the portion located on the outside of the body 1110 can be connected to external structural components, such as busbar components.

[0217] Optionally, the electrode terminal 14 can be connected to the tab 122 via an adapter, for example, one end of the adapter is soldered to the electrode terminal 14 and the other end is soldered to the tab 122.

[0218] In the above solution, by providing electrode terminals 14 on the body 1110, the portion of electrode terminals 14 located on the outside of the body 1110 can utilize the space where the connection portion 1111 is located, making the battery cell 10 compact and having a high volumetric energy density.

[0219] In some embodiments, the first wall 111 may not be provided with electrode terminals 14.

[0220] According to some embodiments of this application, please refer to Figure 10 , Figure 10 This is a schematic diagram of the first wall 111 and the electrode terminal 14 in some embodiments of this application.

[0221] Along the thickness direction z of the first wall, the side of the electrode terminal 14 facing away from the electrode assembly 12 is flush with the side of the connection portion 1111 facing away from the electrode assembly 12.

[0222] In some embodiments, the connecting portion 1111 and the body 1110 on the side opposite to the electrode assembly 12 together form a receiving groove. The side of the body 1110 opposite to the electrode assembly 12 is the bottom surface of the receiving groove, and the inner peripheral surface of the connecting portion 1111 is the peripheral surface of the receiving groove. The electrode terminal 14 is located in the receiving groove, and the side of the electrode terminal 14 opposite to the electrode assembly 12 is flush with the side of the connecting portion 1111 opposite to the electrode assembly 12.

[0223] The phrase "along the thickness direction z of the first wall, the side of the electrode terminal 14 facing away from the electrode assembly 12 is flush with the side of the connecting portion 1111 facing away from the electrode assembly 12" can be understood as follows: in related technologies, the electrode terminal 14 protrudes from the outer side of the first wall 111. In order to improve the problem of cracking of the housing 110, some embodiments of this application raise the periphery of the first wall 111 to form the connecting portion 1111 by utilizing the height of the electrode terminal 14 without increasing the height of the battery cell 10, and make the connecting portion 1111 connected to the housing 110.

[0224] In the above scheme, by setting the side of the electrode terminal 14 away from the electrode assembly 12 to be flush with the side of the connection portion 1111 away from the electrode assembly 12, the electrode terminal 14 can effectively utilize the space where the connection portion 1111 is located, making the battery cell 10 compact and having a high volumetric energy density.

[0225] According to other embodiments of this application, please refer to Figure 11 , Figure 11This is a schematic diagram of the first wall 111 and the electrode terminal 14 in other embodiments of this application. Along the direction of the first wall 111 towards the electrode assembly 12, the electrode terminal 14 protrudes from the side of the connection portion 1111 opposite to the side of the electrode assembly 12.

[0226] In some embodiments, the connecting portion 1111 and the body 1110 together form a receiving groove on the side opposite to the electrode assembly 12, the electrode terminal 14 is located in the receiving groove, and the electrode terminal 14 extends beyond the opening of the receiving groove so that it can be connected to an external structural component, such as being welded to a busbar component.

[0227] Alternatively, in some other embodiments, please refer to Figure 12 , Figure 12 This is a schematic diagram of the first wall 111 and the electrode terminal 14 in other embodiments of this application.

[0228] Along the direction of the electrode assembly 12 toward the first wall 111, the electrode terminal 14 protrudes from the side of the connection portion 1111 away from the electrode assembly 12.

[0229] In some embodiments, the connecting portion 1111 and the body 1110, on the side opposite to the electrode assembly 12, together form a receiving groove, and the electrode terminal 14 is located in the receiving groove, and the electrode terminal 14 is located below the opening of the receiving groove. Optionally, in order to connect the external structural member with the electrode terminal 14, the external structural member may be provided with a corresponding protrusion so that it can be inserted into the opening of the receiving groove to connect with the electrode terminal 14.

[0230] In some embodiments of the above scheme, by setting the side of the electrode terminal 14 away from the electrode assembly 12 to protrude from the side of the connecting portion 1111 away from the electrode assembly 12, it is easier to connect the electrode terminal 14 to external structural components, reducing the difficulty of assembling the battery device 100 and improving the manufacturing efficiency of the battery device 100. In some embodiments, by setting the side of the connecting portion 1111 away from the electrode assembly 12 to protrude from the side of the electrode terminal 14 away from the electrode assembly 12, it is possible to reduce the impact of external impact on the structure of the electrode terminal 14, making the battery cell 10 more reliable, and thus making the battery device 100 more reliable.

[0231] According to some embodiments of this application, the outer casing 11 is an aluminum casing.

[0232] In some embodiments, the outer shell 11 is made of aluminum or an aluminum alloy. That is, the first wall 111 is made of aluminum or an aluminum alloy. When the first wall 111 is made of aluminum, the connecting part 1111 and the body 1110 can be easily formed by the processing technology.

[0233] According to some embodiments of this application, the thickness of the housing 110 is T, which satisfies 0.3mm≤T≤2mm.

[0234] In some embodiments, the housing 110 is made of aluminum, and the thickness T of the housing 110 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm...1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm or any value between two adjacent values.

[0235] According to some embodiments of this application, some embodiments of this application also provide a battery device 100, which includes the battery cell 10 provided above.

[0236] Among them, see Figure 2 As shown, the battery device 100 may also include a housing 20, in which the battery cells 10 are housed.

[0237] In some embodiments, the housing 20 may include a first housing body 21 and a second housing body 22, the first housing body 21 and the second housing body 22 covering each other, the first housing body 21 and the second housing body 22 together defining an assembly space for accommodating the battery cell 10.

[0238] Optionally, the second box body 22 can be a hollow structure with one end open, and the first box body 21 can be a plate-like structure. The first box body 21 covers the open side of the second box body 22 so that the first box body 21 and the second box body 22 together define the assembly space; the first box body 21 and the second box body 22 can also be hollow structures with one side open, and the open side of the first box body 21 covers the open side of the second box body 22.

[0239] Of course, the box 20 formed by the first box body 21 and the second box body 22 can be of various shapes, such as a cylinder or a cuboid. For example, in... Figure 2 In the middle, box 20 has a rectangular structure.

[0240] Optionally, the battery cell 10 disposed within the housing 20 can be one or more. For example, in... Figure 2 In the battery device 100, multiple battery cells 10 are arranged inside the housing 20. The multiple battery cells 10 can be connected in series, parallel, or in a mixed manner. A mixed connection means that the multiple battery cells 10 are connected in both series and parallel. The multiple battery cells 10 can be directly connected in series, parallel, or in a mixed manner, and then the whole assembly of the multiple battery cells 10 is housed in the housing 20. Of course, the battery device 100 can also be formed by first connecting multiple battery cells 10 in series, parallel, or in a mixed manner to form a battery module, and then connecting multiple battery modules in series, parallel, or in a mixed manner to form a whole assembly, which is also housed in the housing 20.

[0241] The battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar component that connects multiple battery cells 10 to achieve electrical connection between the multiple battery cells 10.

[0242] It should be noted that in some embodiments, the battery device 100 may not have a housing 20. The battery device 100 includes multiple battery cells 10, and the battery device 100 composed of multiple battery cells 10 can be directly mounted onto the electrical device to provide power to the electrical device through the multiple battery cells 10. That is, the housing 20 can be part of the electrical device. Taking a vehicle 1000 as an example, the housing 20 can be part of the chassis structure of the vehicle 1000. For example, a portion of the housing 20 can be at least a part of the floor of the vehicle 1000, or a portion of the housing 20 can be at least a part of the crossbeams and longitudinal beams of the vehicle 1000.

[0243] Some embodiments of this application also provide an electrical device, which includes the battery cell 10 provided above and / or the battery device 100 provided above, wherein the battery cell 10 is used to provide electrical energy.

[0244] The electrical device can be any of the aforementioned devices or systems that utilize battery cells 10 and / or battery devices 100. For example, the electrical device can be a vehicle 1000, which can be a range-extended vehicle 1000, a pure electric vehicle 1000, or a gasoline-powered vehicle 1000. The electrical energy provided by the battery cells 10 can be used to meet the power needs of the vehicle 1000 during startup, navigation, and operation.

[0245] According to some embodiments of this application, a battery cell 10 is also provided; please refer to [link to relevant documentation]. Figures 3-12 .

[0246] The battery cell 10 can be an NCM ternary system battery cell 10. The battery cell 10 includes a housing 11, an electrode assembly 12, and electrode terminals 14. The housing 11 is an aluminum shell, and the housing 11 includes a shell 110 and a first wall 111. The shell 110 has an opening, and the first wall 111 is connected to the shell 110 and closes the opening. The electrode assembly 12 is disposed inside the housing 11.

[0247] The first wall 111 includes a main body 1110 and a connecting part 1111.

[0248] Please see Figure 5 and Figure 7A connecting portion 1111 is disposed on the outer periphery of the body 1110, along the direction from the electrode assembly 12 toward the first wall 111. The connecting portion 1111 protrudes from the body 1110 and is welded to the housing 110. In some embodiments, welding equipment or a welding worker can weld the connecting portion 1111 and the housing 110 from the direction from the first wall toward the electrode assembly. Exemplarily, the outer peripheral surface of the connecting portion 1111 contacts the inner wall surface of the housing 110, and a weld mark is formed between the outer peripheral surface of the connecting portion 1111 and the inner wall surface of the housing 110.

[0249] In other embodiments, welding equipment or welders can weld the connection portion 1111 and the housing 110 from the side of the battery cell. Exemplarily, a flange 1112 is provided on the outer periphery of the connection portion 1111. Along the thickness direction z of the first wall, the side of the flange 1112 facing the electrode assembly 12 contacts the end face of the housing 110, and a weld mark is formed between the flange 1112 and the end face of the housing 110.

[0250] Along the radial direction of the first wall 111, there is a distance J between the outer peripheral surface of the body 1110 and the inner wall surface of the shell 110. The value of J can be no less than 0.1 mm and no more than 20 mm. Optionally, the value of J can be no less than 0.5 mm and no more than 10 mm.

[0251] In some embodiments, the inner side of the connecting portion 1111 protrudes beyond the inner side of the body 1110, and the dimension between them is h, where h is not less than 0.1 mm and not more than 10 mm. Optionally, h is not less than 0.5 mm and not more than 5 mm.

[0252] Electrode terminals 14 are disposed on the body 1110 and are electrically connected to the electrode assembly 12 via adapter 13. The side of electrode terminals 14 opposite to the electrode assembly 12 is flush with the side of the connecting portion 1111 opposite to the electrode assembly 12.

[0253] The battery cell 10 provided in the above embodiment has a connecting portion 1111 protruding from the outer periphery of the body 1110 of the first wall 111 along the direction of the electrode assembly 12 pointing towards the first wall 111. This connecting portion 1111 is connected to the housing 110, which increases the distance between the connecting portion 1111 between the first wall 111 and the housing 110 and the electrode assembly 12. Under the condition that the degree of expansion of the electrode assembly 12 is constant, i.e., the amount of deformation of the electrode assembly 12 is constant, the distance between the connecting portion 1111 between the first wall 111 and the housing 110 and the electrode assembly 12 is kept small. The reduced deformation angle leads to reduced strain and decreased stress concentration. This mitigates the problem of fatigue cracking caused by stress concentration at the connection between the first wall 111 and the shell 110 due to the close proximity of the connection 1111 between the battery cell 10 and the electrode assembly 12 as the number of charge-discharge cycles increases. This effectively improves the structural stability of the battery cell 10 shell 11, resulting in high reliability of the battery cell 10 and consequently, high reliability of the battery device 100.

[0254] In some embodiments, a cycle life test is conducted on a conventional battery cell and the battery cell 10 provided above. The test conditions are: the battery cell is charged to 100% and discharged to 10%. Each charge and discharge cycle is counted as one life cycle. The specifications of the battery cells are the same, which are 50mm*200mm*103mm.

[0255] The experimental comparison table is as follows:

[0256] Serial Number Conventional battery cell lifespan The battery cell / lifespan information provided above Experiment 1 2196 11503 Experiment 2 2311 11250 Experiment 3 2296 10922

[0257] As shown in the table above, under the same experimental conditions, the number of charge-discharge cycles of the battery cell 10 provided above is greater than that of a conventional battery cell, and the risk of cracking of the casing 11 of the battery cell 10 provided above is lower than that of cracking of the casing 11 of a conventional battery cell.

[0258] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: An outer casing includes a housing and a first wall, the housing having an opening, and the first wall being connected to the housing and closing the opening; Electrode assembly, disposed within the housing; The first wall includes a body and a connecting portion. The connecting portion is disposed on the outer periphery of the body along the direction from the electrode assembly to the first wall. The connecting portion protrudes from the body and is connected to the housing.

2. The battery cell according to claim 1, characterized in that, Along the thickness direction of the first wall, the connecting portion has a first surface facing the electrode assembly, and the body has a second surface facing the electrode assembly. The first surface protrudes from the second surface by a dimension h, satisfying 0.1mm≤h≤10mm.

3. The battery cell according to claim 2, characterized in that, It satisfies 0.5mm≤h≤5mm.

4. The battery cell according to claim 1, characterized in that, Along the thickness direction of the first wall, the thickness of the connecting part is t, which satisfies 0.5mm≤t≤10mm.

5. The battery cell according to claim 4, characterized in that, It satisfies 1mm≤t≤8mm.

6. The battery cell according to claim 1, characterized in that, The electrode assembly includes an electrode sheet having a flat region, the flat region being stacked along a first direction, the first direction being perpendicular to the thickness direction of the first wall; Along the first direction, the outermost straight region of the electrode assembly has a third surface facing the first wall in the thickness direction of the first wall, and the connecting portion has a first surface facing the electrode assembly along the thickness direction of the first wall. The distance between the third surface and the first surface is H, which satisfies 2mm≤H≤20mm.

7. The battery cell according to claim 6, characterized in that, It must satisfy 3mm≤H≤15mm.

8. The battery cell according to claim 1, characterized in that, Along the thickness direction of the first wall, the connecting portion has a first surface facing the electrode assembly, the body has a second surface facing the electrode assembly, and along the radial direction of the first wall, the body has a fourth surface, the fourth surface connecting the first surface and the second surface, and the fourth surface being spaced apart from the inner wall surface of the housing.

9. The battery cell according to claim 8, characterized in that, Along the radial direction of the first wall, the distance between the fourth surface and the inner wall of the shell is J, which satisfies 0.1mm≤J≤20mm.

10. The battery cell according to claim 9, characterized in that, It satisfies 0.5mm≤J≤10mm.

11. The battery cell according to claim 1, characterized in that, The connecting part is connected to the housing through a first connecting part, the outer peripheral surface of the connecting part is in contact with the inner wall surface of the housing, and the first connecting part is located between the outer peripheral surface of the connecting part and the inner wall surface of the housing.

12. The battery cell according to claim 11, characterized in that, The first joint includes a first solder mark formed between the connecting portion and the housing.

13. The battery cell according to claim 1, characterized in that, The connecting part is connected to the housing through the second connecting part. The outer periphery of the connecting part is provided with a flange. Along the thickness direction of the first wall, the side of the flange facing the electrode assembly contacts the end face of the housing. The second connecting part is located between the flange and the end face of the housing.

14. The battery cell according to claim 13, characterized in that, The second joint includes a second solder mark formed between the flange and the housing.

15. The battery cell according to claim 1, characterized in that, The connecting part and the body are integrally formed.

16. The battery cell according to claim 15, characterized in that, Along the thickness direction of the first wall, the first wall is recessed on the side opposite to the electrode assembly and corresponding to the position of the body to form the body and the connecting portion.

17. The battery cell according to any one of claims 1-16, characterized in that, The battery cell also includes electrode terminals, which are disposed on the body and electrically connected to the electrode assembly.

18. The battery cell according to claim 17, characterized in that, Along the thickness direction of the first wall, the side of the electrode terminal facing away from the electrode assembly is flush with the side of the connection portion facing away from the electrode assembly.

19. The battery cell according to claim 17, characterized in that, Along the direction from the first wall toward the electrode assembly, the side of the electrode terminal opposite to the electrode assembly protrudes from the side of the connection portion opposite to the electrode assembly; or, along the direction from the electrode assembly toward the first wall, the side of the electrode terminal opposite to the electrode assembly protrudes from the side of the connection portion opposite to the electrode assembly.

20. The battery cell according to claim 1, characterized in that, The outer shell is made of aluminum.

21. The battery cell according to claim 20, characterized in that, The thickness of the shell is T, which satisfies 0.3mm≤T≤2mm.

22. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-21.

23. An electrical appliance, characterized in that, Includes the battery cell according to any one of claims 1-21, and / or the battery device according to claim 22.

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