Battery cell, battery device and electric device

Abstract

Disclosed in the present application are a battery cell, a battery device and an electric device. The battery cell comprises a casing, an electrode assembly, and electrode terminals, wherein an accommodating cavity is formed inside the casing, and the casing comprises a first wall, a second wall and a third wall. In a first direction, the first wall and the third wall are arranged opposite each other, the second wall is located between the first wall and the third wall, and the second wall connects the first wall and the third wall. The electrode assembly is arranged in the accommodating cavity. The electrode terminals are arranged on the casing and are electrically connected to the electrode assembly, and the electrode terminals are located on a wall portion of the casing other than the first wall, the second wall and the third wall. The face of the first wall facing the interior of the accommodating cavity is defined as a first face, the face of the second wall facing the interior of the accommodating cavity is defined as a second face, the first face is directly connected to the second face, and the connection region forms a first preset included angle, which is not less than 85° and not greater than 95°. The technical solution provided in the present application can effectively improve the reliability of the battery device.

Description

Battery cells, battery packs and electrical devices 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.

[0004] Summary of the Invention

[0005] 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.

[0006] In a first aspect, some embodiments of this application provide a battery cell, which includes a housing, an electrode assembly, and electrode terminals. A receiving cavity is formed inside the housing, and the housing includes a first wall, a second wall, and a third wall. Along a first direction, the first wall and the third wall are disposed opposite each other, and a second wall is located between the first wall and the third wall, and the second wall connects the first wall and the third wall. The electrode assembly is disposed within the receiving cavity. The electrode assembly has a stacked structure, and the first direction is the stacking direction of the electrode assembly; or, the electrode assembly has a wound structure, and the electrode assembly includes a planar region located in the middle and corner regions located on both sides, and the first direction is the stacking direction of the electrode assembly in the planar region. The electrode terminals are disposed on the housing and electrically connected to the electrode assembly, and the electrode terminals are located on other walls of the housing other than the first wall, the second wall, and the third wall. The surface of the first wall facing the receiving cavity is called the first surface, and the surface of the second wall facing the receiving cavity is called the second surface. The first surface and the second surface are directly connected, and the connection area forms a first preset angle, which is not less than 85° and not greater than 95°.

[0007] In related technologies, as the number of charge-discharge cycles of a battery cell increases, the battery cell expands internally. The expansion force of the battery cell in the first direction is relatively large, meaning that the electrode assembly is more likely to expand towards the first and third walls. In the above-mentioned solution, by setting the first surface of the first wall to be directly connected to the second surface of the second wall, and making the first preset angle between the first surface and the second surface a right angle or close to a right angle, the risk of the electrode assembly structure being damaged due to the interference of the inner rounded corner between the first wall and the second wall, which leads to a decrease in the reliability of the battery cell, can be reduced, thereby effectively improving the reliability of the battery device.

[0008] According to some embodiments of this application, the electrode assembly includes a body and an insulating film, the insulating film covering at least a portion of the body and in direct contact with a second wall.

[0009] In the above solution, by setting the first surface of the first wall to be directly connected to the second surface of the second wall, and making the first preset included angle between the first surface and the second surface a right angle or close to a right angle, there is no inner rounded corner between the first surface and the second surface. This can effectively reduce the risk of mutual interference between the electrode assembly and the junction of the first surface and the second surface, thereby eliminating the need for the bottom support plate in related technologies, and allowing the insulating film to directly contact the second surface. This can improve the space utilization of the electrode assembly, thereby increasing the volumetric energy density of the battery cell and thus facilitating the improvement of the volumetric energy density of the battery device.

[0010] According to some embodiments of this application, the first wall and the second wall are welded together.

[0011] In the above solution, the two independent structures, the first wall and the second wall, are welded together as one unit, eliminating the inner rounded corners between them. This approach improves the interference of the junction between the first and second walls with the electrode assembly, reducing structural damage to the electrode assembly and impacting battery reliability. Furthermore, it eliminates the need for a base plate, improving the space utilization of the electrode assembly and thus increasing the volumetric energy density of the battery cell, ultimately benefiting the overall volumetric energy density of the battery device. Finally, the welding process is simple, the connection is reliable, and the manufacturing efficiency is high, contributing to improved battery device manufacturing efficiency.

[0012] According to some embodiments of this application, the surface of the third wall facing the cavity is called the third surface, the third surface and the second surface are directly connected and the connection area forms a second preset angle, the second preset angle is not less than 85° and not greater than 95°.

[0013] In the above solution, by setting the third surface of the third wall to be directly connected to the second surface of the second wall, and making the second preset angle between the third surface and the second surface a right angle or an angle close to a right angle, the risk of the electrode assembly structure being damaged due to the interference of the inner rounded corner between the third wall and the second wall, resulting in a decrease in the reliability of the battery cell, can be reduced, thereby effectively improving the reliability of the battery device.

[0014] According to some embodiments of this application, the third wall and the second wall are welded together.

[0015] In the above solution, the two independent structures of the third wall and the second wall are welded together, eliminating the inner rounded corner between them. This approach improves the interference of the junction between the third and second walls with the electrode assembly, reducing structural damage and ensuring battery reliability. Furthermore, it eliminates the need for a base plate, improving space utilization and increasing the volumetric energy density of the battery cells, thus enhancing the overall volumetric energy density of the battery device. Finally, the welding process is simple, the connection is reliable, and the manufacturing efficiency is high, contributing to improved battery device manufacturing efficiency.

[0016] According to some embodiments of this application, the outer casing further includes a fourth wall and a fifth wall, which are opposite to each other along a second direction, and the first and second directions are perpendicular to each other. The surface of the fourth wall facing the cavity is the fourth surface, and the fourth surface and the second surface are directly connected, with the connection area forming a third preset angle, which is not less than 85° and not greater than 95°; and / or the surface of the fifth wall facing the cavity is the fifth surface, and the fifth surface and the second surface are directly connected, with the connection area forming a fourth preset angle, which is not less than 85° and not greater than 95°.

[0017] In the above scheme, by setting the fourth surface of the fourth wall to be directly connected to the second surface of the second wall, and making the third preset angle between the fourth surface and the second surface a right angle or close to a right angle, the risk of the electrode assembly structure being damaged due to interference from the inner rounded corner between the fourth wall and the second wall, resulting in a decrease in the reliability of the battery cell, can be mitigated, thereby effectively improving the reliability of the battery device. At the same time, by setting the fifth surface of the fifth wall to be directly connected to the second surface of the second wall, and making the fourth preset angle between the fifth surface and the second surface a right angle or close to a right angle, the risk of the electrode assembly structure being damaged due to interference from the inner rounded corner between the fifth wall and the second wall, resulting in a decrease in the reliability of the battery cell, can be mitigated, thereby effectively improving the reliability of the battery device.

[0018] According to some embodiments of this application, the fourth wall and the second wall are welded together; and / or the fifth wall and the second wall are welded together.

[0019] In the above solution, the two independent structures of the fourth and second walls are welded together, and the two independent structural lines of the fifth and second walls are welded together. This eliminates the need for internal rounded corners between the fourth and second walls, as well as between the fifth and second walls. This approach addresses two main issues: firstly, it mitigates interference with the electrode assembly at the junctions of the fourth and second walls, and the fifth and second walls, reducing structural damage to the electrode assembly and improving battery reliability; secondly, it eliminates the need for a base plate, increasing the space utilization of the electrode assembly and thus improving the volumetric energy density of the battery cell, ultimately contributing to a higher volumetric energy density of the battery device; and thirdly, the welding process is simple, the connection is reliable, and the manufacturing efficiency is high, improving the overall manufacturing efficiency of the battery device.

[0020] According to some embodiments of this application, the outer shell includes a housing, which is an integral structure. The housing includes a first wall, a third wall, a fourth wall, and a fifth wall. Along the thickness direction of the second wall, one end of the housing has a first opening, and the second wall closes the first opening.

[0021] In the above solution, the integrated housing includes a first wall, a third wall, a fourth wall, and a fifth wall. By connecting the second wall to the first, third, fourth, and fifth walls respectively, the first opening of the housing can be closed to support the electrode assembly or provide a closed space for the electrode assembly. On the other hand, the junction between the housing and the second wall is free of inner rounded corners, reducing interference between the housing and the electrode assembly. This eliminates the need for a bottom support plate in related technologies, thus balancing the reliability of the battery cell and the improvement of energy density. Furthermore, the assembly of the integrated housing and the first wall is less difficult during manufacturing, resulting in high manufacturing efficiency for the battery cell and consequently, high manufacturing efficiency for the battery device.

[0022] According to some embodiments of this application, the housing further includes a sixth wall, and along the thickness direction of the second wall, the other end of the housing has a second opening, which is closed by the sixth wall.

[0023] In the above solution, the outer shell includes a shell, a sixth wall, and a second wall, which are separate structures and are connected to each other. On the one hand, this improves the problem of interference between the shell and the second wall and the electrode assembly, which causes damage to the electrode assembly structure and affects the reliability of the battery cell. On the other hand, it can reduce the molding difficulty of the outer shell and reduce the manufacturing cost of the battery cell during the manufacturing and assembly process of the battery cell.

[0024] According to some embodiments of this application, along the circumference of the outer casing, the opposite ends of the fourth wall are bent to the first wall and the third wall, respectively. Along the circumference of the outer casing, the fifth wall includes a first portion and a second portion, the first portion being bent to the first wall and the second portion being bent to the third wall, the first portion and the second portion being welded together.

[0025] In the above solution, a plate-like structure can be bent to form a shell-like structure, and the first and second parts can be connected to each other to form a shell through welding. That is, the shell can be manufactured through a bending process and a welding process, which simplifies the manufacturing process of the shell, speeds up the process cycle, and helps to improve the manufacturing efficiency of battery cells, thereby improving the manufacturing efficiency of battery devices.

[0026] According to some embodiments of this application, the housing further includes a sixth wall. Along the circumference of the housing, the first wall, the third wall, the fourth wall, and the fifth wall surround the edge of the sixth wall. Along the thickness direction of the second wall, the sixth wall and the second wall are opposite to each other.

[0027] In the above scheme, the shell, which is an integral structure, includes a sixth wall and a first wall, a third wall, a fourth wall, and a fifth wall surrounding the edge of the sixth wall. This makes the shell a cylindrical structure that is closed at one end and open at the other. On the one hand, this facilitates the assembly of electrode components, reduces the assembly process of battery cells, and improves the manufacturing efficiency of battery devices. On the other hand, it reduces the number of connection interfaces on the surface of the shell, which helps improve the airtightness of battery cells, improves the reliability of battery cells, and thus improves the reliability of battery devices.

[0028] According to some embodiments of this application, electrode terminals are disposed on the sixth wall.

[0029] In the above solution, by setting the electrode terminal at the sixth end to connect with the tab lead-out end of the electrode assembly, the second wall can contact the other end of the electrode terminal without being interfered with by the junction of the second wall and the shell. This eliminates the need for the bottom support plate in the related technology, thereby improving the volumetric energy density of the battery cell and the volumetric energy density of the battery device.

[0030] According to some embodiments of this application, the first wall, the third wall, the fourth wall and the fifth wall are separate structures, the opposite ends of the fourth wall along the second direction are respectively welded to the first wall and the third wall, and the opposite ends of the fifth wall along the second direction are respectively welded to the first wall and the third wall.

[0031] In the above scheme, the outer shell is composed of multiple split structures welded together, which can effectively reduce the interference of the connection interface between the inner walls of the outer shell on the electrode components, which is conducive to improving the space utilization of the battery components, thereby improving the volumetric energy density of the battery cells, and further improving the volumetric energy density of the battery device.

[0032] According to some embodiments of this application, electrode terminals are disposed on the wall portion of the housing opposite to the second wall along the thickness direction of the second wall.

[0033] In the above scheme, the electrode terminals are located on the side of the outer casing away from the second wall, that is, the electrode assembly is a single-sided electrode tab, which can reduce the space occupied by the electrode terminals and electrode assembly in the thickness direction of the second wall, which is conducive to improving the volumetric energy density of the battery cell and the volumetric energy density of the battery device.

[0034] According to some embodiments of this application, electrode terminals are disposed on the wall portion of the housing along the second direction, wherein the first direction, the second direction, and the thickness direction of the second wall are perpendicular to each other.

[0035] In the above solution, by setting the electrode terminals on the wall of the outer casing along the second direction, the space occupied by the electrode terminals and electrode assembly in the thickness direction of the second wall and the first direction can be reduced, which is conducive to improving the volumetric energy density of the battery cell and the volumetric energy density of the battery device. In related technologies, especially in blade batteries, the surface of the outer casing along the second direction is the side surface (small surface). By setting the electrode terminals on the side surface, the high volumetric energy density of the blade battery can be fully utilized to further improve the volumetric energy density of the battery device.

[0036] According to some embodiments of this application, the electrode terminals include a first electrode terminal and a second electrode terminal with opposite polarities. The first electrode terminal is disposed on one wall of the housing along a second direction, and the second electrode terminal is disposed on another wall of the housing along the second direction.

[0037] In the above scheme, by setting the first electrode terminal and the second electrode terminal with opposite polarities on two opposite walls of the outer casing along the second direction, the negative electrode charge state distribution can be made more uniform, thereby reducing the risk of lithium plating, effectively reducing the risk of internal short circuit and heat generation in the battery cell, improving the reliability of the battery cell, and contributing to the improvement of the reliability of the battery device.

[0038] According to some embodiments of this application, the outer shell is made of steel, and the thickness of the outer shell is not less than 0.075 mm and not more than 0.3 mm.

[0039] In the above scheme, the outer shell is made of steel with high structural strength. With the overall structural strength of the battery cell, the wall thickness of the shell can be greatly reduced. For example, the thickness of the shell is limited to not less than 0.075mm and not more than 0.3mm, thereby reducing the proportion of the shell in the battery cell and enabling the battery cell to have a higher volumetric energy density, which is beneficial to improving the volumetric energy density of the battery device.

[0040] According to some embodiments of this application, the first wall and the second wall are connected by a first connecting portion, the first surface is in contact with the outer peripheral surface of the second wall, the first connecting portion is located between the outer peripheral surfaces of the first surface and the second wall along a first direction, and a portion of the first connecting portion is located on the side of the second wall away from the receiving cavity.

[0041] In the above scheme, the first surface is connected to the second wall through the first connecting part and the outer peripheral surface of the first surface is in contact with the second wall. The part of the first connecting part is located on the side of the second wall away from the receiving cavity, which makes the connection between the first wall and the second wall easier. For example, the junction of the first wall and the second wall can be welded from the side of the first wall away from the receiving cavity, which can effectively improve the connection efficiency of the first wall and the second wall, thereby improving the manufacturing efficiency of the battery cell.

[0042] According to some embodiments of this application, the first connection portion includes a solder mark formed between the first wall and the second wall.

[0043] According to some embodiments of this application, the first wall and the second wall are connected by a first connecting portion. Along the thickness direction of the second wall, a protrusion is formed on the side of the second wall facing the receiving cavity. The outer peripheral surface of the protrusion contacts the first surface. Along the thickness direction of the second wall, the first connecting portion is located between the end face of the first wall and the second wall.

[0044] In the above solution, by providing a protrusion on the side of the second wall facing the receiving cavity, the second wall and the first wall can be positioned relative to each other, which can reduce the risk of misalignment between the second wall and the first wall, thereby improving the connection reliability of the first wall and the second wall and improving the structural reliability of the battery cell.

[0045] According to some embodiments of this application, the first connection portion includes a solder mark formed between the first wall and the second wall.

[0046] Secondly, some embodiments of this application also provide a battery device, including the battery cell provided in the first aspect.

[0047] Thirdly, some embodiments of this application also provide an electrical device, including a battery cell provided in the first aspect and / or a battery device provided in the second aspect, wherein the battery cell is used to provide electrical energy.

[0048] 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

[0049] 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.

[0050] Figure 1 is a schematic diagram of the vehicle structure in some embodiments of this application;

[0051] Figure 2 is an exploded perspective view of the battery device in some embodiments of this application;

[0052] Figure 3 is an exploded perspective view of a battery cell in some embodiments of this application;

[0053] Figure 4 is a schematic diagram of the internal structure of the first wall, the second wall, and the electrode assembly in some embodiments of this application;

[0054] Figure 5 is a schematic diagram of the structure of the fourth wall, the fifth wall and the second wall in some embodiments of this application;

[0055] Figure 6 is an exploded perspective view of the outer casing in some embodiments of this application;

[0056] Figure 7 is an exploded perspective view of the outer casing in some other embodiments of this application;

[0057] Figure 8 is a schematic diagram of a battery cell in some other embodiments of this application;

[0058] Figure 9 is an enlarged view of point A in Figure 4;

[0059] Figure 10 is a schematic diagram of the structure of the first wall, the second wall and the third wall in some other embodiments of this application;

[0060] Figure 11 is an enlarged view of point B in Figure 10.

[0061] Icons: 1000 - Vehicle; 100 - Battery Unit; 200 - Controller; 300 - Motor; 10 - Battery Cell; 20 - Housing; 21 - First Housing Section; 22 - Second Housing Section; 30 - Outer Shell; 30a - Housing; 30b - First Opening; 30c - Second Opening; 31 - First Wall; 310 - First Surface; 32 - Second Wall; 320 - Second Surface; 321 - Protrusion; 322 - Body; 33 - Third Wall; 330 - Third side; 34-Fourth wall; 340-Fourth side; 35-Fifth wall; 350-Fifth side; 351-First part; 352-Second part; 36-Sixth wall; 11-Electrode assembly; 110-Main body; 111-Insulating film; 12-Electrode terminal; 12a-First electrode terminal; 12b-Second electrode terminal; 12c-Adapter; 13-First connecting part; x-First direction; y-Second direction; z-Thickness direction of the second 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), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[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 cycle life, discharge capacity, and charge / discharge rate performance parameters. Furthermore, the energy density and reliability of the battery device also need to be taken into account.

[0099] In battery technology, a single battery cell includes a casing, electrode assemblies, and electrode terminals. The electrode assemblies are housed within the casing, and the electrode terminals are located on the walls of the casing and electrically connected to the electrode assemblies. In related technologies, the casing typically includes a housing and end caps. The housing has an opening through which the electrode assemblies are inserted. The end caps close the opening and connect to the housing, placing the electrode assemblies within a closed space. The electrode terminals are located on the end caps and electrically connected to the electrode assemblies. Generally, the housing is a one-piece structure, usually formed using a stamping process. The junction between adjacent walls of the housing has inner rounded corners, which can interfere with the electrode assemblies, causing structural damage. In particular, as the number of charge-discharge cycles increases, the battery cell expands internally. The larger surfaces of the casing are significantly affected by this expansion force, and the inner rounded corners of these surfaces and adjacent walls have an even greater impact on the electrode assemblies, easily causing structural damage and affecting the reliability of the battery cell, thereby impacting the reliability of the battery assembly.

[0100] In view of this, to reduce the risk of interference to the electrode assembly at the junctions between the outer casing walls and to improve the reliability of the battery device, some embodiments of this application provide a battery cell, which includes a casing, an electrode assembly, and electrode terminals. A receiving cavity is formed inside the casing, which includes a first wall, a second wall, and a third wall. The first and third walls are disposed opposite each other along a first direction x, and a second wall is located between the first and third walls and connects the first and third walls. The electrode assembly is disposed within the receiving cavity. The electrode assembly has a stacked structure, where the first direction x is the stacking direction of the electrode assembly; or, the electrode assembly has a wound structure, including a planar region in the middle and corner regions on both sides, where the first direction x is the stacking direction of the electrode assembly in the planar region. The electrode terminals are disposed on the casing and electrically connected to the electrode assembly, and are located on other walls of the casing besides the first, second, and third walls. The first wall facing the cavity is called the first surface, and the second wall facing the cavity is called the second surface. The first surface and the second surface are directly connected and the connection area forms a first preset angle, which is not less than 85° and not greater than 95°.

[0101] In related technologies, as the number of charge-discharge cycles of a battery cell increases, the battery cell expands internally. The expansion force of the battery cell in the first direction x is relatively large, meaning that the electrode assembly is more likely to expand towards the first and third walls. In the above-mentioned solution, by setting the first surface of the first wall to be directly connected to the second surface of the second wall, and making the first preset angle between the first surface and the second surface a right angle or close to a right angle, the risk of interference of the inner rounded corner between the first wall and the second wall on the electrode assembly, which would damage the electrode assembly structure and reduce the reliability of the battery cell, can be reduced. This can effectively improve the reliability of the battery device.

[0102] The battery device disclosed in this application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be composed of the battery device disclosed in this application. This helps to mitigate the problem of short circuits during battery use, thereby improving the reliability of the battery device, increasing the volumetric energy density of the battery device, and extending the operating time of the electrical device.

[0103] This application provides an electrical device that uses a battery 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, which is a structural schematic diagram 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 vehicle's operating power source or general power source. 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, which is an exploded perspective view of the battery device 100 in some embodiments of this application.

[0108] The battery device 100 includes a battery cell 10 and a housing 20, with the battery cell 10 housed within the housing 20. The housing 20 provides a space for the battery cell 10 and can have various structures. In some embodiments, the housing 20 may include a first housing portion 21 and a second housing portion 22, which overlap each other, together defining a space for accommodating the battery cell 10. The second housing portion 22 may be a hollow structure with one open end, while the first housing portion 21 may be a plate-like structure, covering the open side of the second housing portion 22 so that the first housing portion 21 and the second housing portion 22 together define the space. Alternatively, both the first housing portion 21 and the second housing portion 22 may be hollow structures with one open side, with the open side of the first housing portion 21 covering the open side of the second housing portion 22. Of course, the box 20 formed by the first box part 21 and the second box part 22 can be of various shapes, such as cylinder, cuboid, etc.

[0109] In the battery, there can be one or more battery cells 10, and each battery cell 10 can be fixed to the housing 20 by means of connectors (such as bolts), or each battery cell 10 can be fixed to the housing 20 by means of adhesive bonding.

[0110] In some embodiments, the battery cells 10 in the housing 20 can be electrically connected through a busbar, allowing the battery cells 10 in the housing 20 to be connected in series, parallel, or mixed. For example, the housing 20 is provided with multiple battery cell assemblies, each battery cell assembly including multiple stacked battery cells 10, which are connected in series through a busbar. In some embodiments, the multiple battery cell assemblies can be connected in series through a busbar.

[0111] According to some embodiments of this application, a battery cell 10 is provided. Please refer to Figures 3 and 4. Figure 3 is an exploded perspective view of the battery cell 10 in some embodiments of this application, and Figure 4 is a schematic diagram of the internal structure of the first wall 31, the second wall 32, and the electrode assembly 11 in some embodiments of this application.

[0112] The battery cell 10 includes a housing 30, an electrode assembly 11, and electrode terminals 12. The housing 30 has an internal cavity and includes a first wall 31, a second wall 32, and a third wall 33. Along a first direction x, the first wall 31 and the third wall 33 are positioned opposite each other, and the second wall 32 is located between the first wall 31 and the third wall 33, connecting the first wall 31 and the third wall 33. The electrode assembly 11 is disposed within the cavity. The electrode assembly 11 has a stacked structure, where the first direction x is the stacking direction of the electrode assembly 11; or, the electrode assembly 11 has a wound structure, including a central planar region and corner regions on both sides, where the first direction x is the stacking direction of the electrode assembly 11 in the planar region. The electrode terminals 12 are disposed on the housing 30 and electrically connected to the electrode assembly 11, and are located on other walls of the housing 30 besides the first wall 31, the second wall 32, and the third wall 33. The surface of the first wall 31 facing the cavity is called the first surface 310, and the surface of the second wall 32 facing the cavity is called the second surface 320. The first surface 310 and the second surface 320 are directly connected and the connection area forms a first preset angle, which is not less than 85° and not greater than 95°.

[0113] In some embodiments, the battery cell 10 includes a housing 30 and an electrode assembly 11, the electrode assembly 11 and the electrolyte being encapsulated within the enclosed space of the housing 30. The housing 30 may be a rectangular housing 30, and the housing 30 includes a plurality of walls that are interconnected and enclose a receiving cavity for accommodating the electrode assembly 11.

[0114] In some embodiments, the housing 30 may include six wall portions, including a first wall 31, a second wall 32, a third wall 33, a fourth wall 34, a fifth wall 35, and a sixth wall 36. The first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 may be connected end to end along the circumference of the housing 30 to form the circumferential wall of the housing 30, and the second wall 32 and the sixth wall 36 are disposed opposite to each other.

[0115] In some embodiments, the housing 30a may be made of a metal, such as aluminum, steel, or a composite metal. Alternatively, in other embodiments, the housing 30a may be made of a non-metallic material, such as plastic.

[0116] In some embodiments, the materials of the various walls of the housing 30a may be the same or different. For example, the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 may be made of steel, and the second wall 32 and the sixth wall 36 may be made of steel; or the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 may be made of aluminum, and the second wall 32 and the sixth wall 36 may be made of steel; or the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 may be made of steel, and the second wall 32 and the sixth wall 36 may be made of aluminum.

[0117] In some embodiments, the number of electrode assemblies 11 can be one or more. Optionally, referring to FIG3, the battery cell 10 includes two electrode assemblies 11, which are stacked in the housing 30.

[0118] The electrode assembly 11 has various structural forms, including a wound structure and a stacked structure. In some embodiments, the wound structure can be understood as an electrode assembly 11 formed by stacking positive electrode, separator and negative electrode and then winding them. Optionally, as shown in FIG3, the electrode assembly 11 in FIG3 can be a wound structure, which includes a planar region located in the middle and corner regions located on both sides. That is, the electrode assembly 11 includes several straight segments and corner segments. The several straight segments are stacked together along the first direction x, and adjacent two straight segments are connected by corner segments.

[0119] In some embodiments, the stacked structure can be understood as a plurality of groups of positive electrode plates, separators and negative electrode plates stacked along a first direction x to form an electrode assembly 11, wherein the positive electrode plates and negative electrode plates in each group are separated by a separator.

[0120] Generally, the first direction x described above refers to the direction in which the battery cell 10 expands to a greater extent. When the outer casing 30 is a square outer casing 30, the wall surface of the outer casing 30 in the first direction x is the larger surface. In some embodiments of this application, the first wall 31 and the third wall 33 are the larger surfaces of the outer casing 30, that is, the first wall 31 and the third wall 33 correspond to the wall portions that are more affected when the battery cell 10 expands.

[0121] In some embodiments, the first wall 31 and the third wall 33 can be the larger walls of the housing 30, i.e., the larger surfaces, and the second wall 32 can be the wall connecting the first wall 31 and the third wall 33. The second wall 32 can be the bottom wall or the top wall of the housing 30. For example, in some usage scenarios of the battery cell 10, the second wall 32 is the bottom wall of the housing 30, and the second wall 32 can serve to support the electrode assembly 11. In other usage scenarios of the battery cell 10, the battery cell 10 is used upside down, and the second wall 32 can be the top wall of the housing 30.

[0122] Electrode terminal 12 is a component disposed on the housing 30. Electrode terminal 12 is used to connect the tabs of electrode assembly 11 and an external busbar to realize the input and output of electrical energy of battery cell 10. Exemplarily, one end of electrode terminal 12 inside battery cell 10 can be connected to the tabs of electrode assembly 11 via an adapter, and the other end of electrode terminal 12 outside battery cell 10 can be connected to an external busbar, allowing current to flow into or out of the tabs and external busbar through electrode terminal 12. In some embodiments, electrode terminal 12 can be a cylindrical structure, a polygonal prism structure, or a composite structure of cylindrical and polygonal prisms. In some embodiments, electrode terminal 12 is made of a metallic material, such as aluminum, copper, iron, steel, alloys, or composite metals.

[0123] In some embodiments of this application, the electrode terminal 12 is disposed on other walls besides the first wall 31, the second wall 32, and the third wall 33. That is, the electrode terminal 12 is not disposed on the first wall 31, the second wall 32, and the third wall 33, but may be disposed on the fourth wall 34, the fifth wall 35, or the sixth wall 36. The electrode terminal 12 can be electrically connected to the electrode assembly 11 through the adapter 12c.

[0124] In some embodiments, the battery cell 10 may include a first electrode terminal 12a and a second electrode terminal 12b, the first electrode terminal 12a and the second electrode terminal 12b having opposite polarities. For example, the first electrode terminal 12a is the positive electrode and is used to connect to the positive electrode tab, and the second electrode terminal 12b is the negative electrode and is used to connect to the negative electrode tab. The first electrode terminal 12a and the second electrode terminal 12b may be disposed on the same wall portion or different walls portion of the housing 30. Exemplarily, the first electrode terminal 12a and the second electrode terminal 12b may both be disposed on a sixth wall 36; or, the first electrode terminal 12a may be disposed on a fourth wall 34, and the second electrode terminal 12b may be disposed on a fifth wall 35.

[0125] In some embodiments, the first surface 310 is the surface of the first wall 31 facing into the receiving cavity. Optionally, the first surface 310 can be the inner surface of the first wall 31, that is, along the thickness direction of the first wall 31, the first surface 310 is the surface of the first wall 31 closest to the electrode assembly 11. The second surface 320 is the surface of the second wall 32 facing into the receiving cavity. Optionally, the second surface 320 can be the inner surface of the second wall 32, that is, along the thickness direction z of the second wall, the second surface 320 is the surface of the second wall 32 closest to the electrode assembly 11.

[0126] The phrase "the first surface 310 and the second surface 320 are directly connected and the connection area forms a first preset angle" can be understood as follows: the first surface 310 and the second surface 320 can be flat surfaces, and there is no transition between them through other parts, such as no transition through inner rounded corners, and the angle between the first surface 310 and the second surface 320 is the first preset angle. Optionally, referring to Figure 4, the flat first surface 310 and the flat second surface 320 are directly connected, and the first preset angle between the first surface 310 and the second surface 320 is 90° or close to 90°. For example, referring to Figure 4, the first preset angle between the first surface 310 and the second surface 320 is R1. The value of R1 can be a value that is not less than 85° and not greater than 95°, such as 85°, 86°, 87°, 88°, 89°, 90°, 91°, 92°, 93°, 94°, 95°, or any value between two adjacent values.

[0127] In some embodiments, the first wall 31 and the second wall 32 can be separate structures that are spliced ​​together to make the first surface 310 and the second surface 320 directly connected and the connection area forms a first preset angle. Optionally, when manufacturing the shell 30, the second wall 32 is a plate-like structure, and the first wall 31 is positioned at the edge of the second wall 32. The first wall 31 and the second wall 32 are combined into one by a connection process, such as welding, bonding or other processes, so that there is no inner rounded corner between the first wall 31 and the second wall 32.

[0128] Optionally, the third wall 33 and the second wall 32 can be separate structures, but can be joined together as one unit through welding, bonding, or other processes. Alternatively, the third wall 33 and the second wall 32 can be an integral structure, formed by casting, die casting, or bending processes. For example, the second wall 32 can be bent into the third wall 33.

[0129] In related technologies, as the number of charge-discharge cycles of the battery cell 10 increases, the battery cell 10 expands internally, and the expansion force of the battery cell 10 in the first direction x is relatively large. That is, the electrode assembly 11 is more likely to expand towards the first wall 31 and the third wall 33. In the above solution, by setting the first surface 310 of the first wall 31 to be directly connected to the second surface 320 of the second wall 32, and making the first preset included angle between the first surface 310 and the second surface 320 a right angle or an angle close to a right angle, the risk of the electrode assembly 11 being damaged due to the interference of the inner rounded corner between the first wall 31 and the second wall 32, resulting in a decrease in the reliability of the battery cell 10, can be reduced. This can effectively improve the reliability of the battery device 100.

[0130] According to some embodiments of this application, please refer to Figures 3 and 4. The electrode assembly 11 includes a body 110 and an insulating film 111. The insulating film 111 covers at least a portion of the body 110 and is in direct contact with the second wall 32.

[0131] In some embodiments, the electrode assembly 11 includes a body 110 and an insulating film 111. The body 110 can be understood as the main structure of the electrode assembly 11 composed of a positive electrode, a negative electrode, and a separator. The insulating film 111 is a film-shaped insulating structure covering at least a portion of the body 110. In some embodiments, the insulating film 111 may be a Mylar film.

[0132] In some embodiments, the body 110 has a lead-out end, from which a tab extends, and an insulating film 111 may cover other portions of the lead-out end of the body 110; or the insulating film 111 may cover the entire body 110, with the tab extending from the lead-out end and passing through the insulating film 111. Optionally, referring to FIG3, the body 110 is generally flat, with its upper end being the lead-out end, and the insulating film 111 covering the peripheral wall and lower end of the body 110.

[0133] "The insulating film 111 is in direct contact with the second wall 32" can be understood as meaning that no other structural components are provided between the insulating film 111 and the second wall 32, and the insulating film 111 can be in direct contact with the second wall 32. In some embodiments, the second wall 32 is a wall portion without electrode terminals 12, or it can be a wall portion supporting the electrode assembly 11. The second wall 32 can be in direct contact with the electrode assembly 11, and no structural components such as a base plate are provided between them.

[0134] In the above solution, by setting the first surface 310 of the first wall 31 to be directly connected to the second surface 320 of the second wall 32, and making the first preset included angle between the first surface 310 and the second surface 320 a right angle or close to a right angle, there is no inner rounded corner between the first surface 310 and the second surface 320. This can effectively reduce the risk of mutual interference between the electrode assembly 11 and the junction of the first surface 310 and the second surface 320, thereby eliminating the need for the bottom support plate in the related technology, and allowing the insulating film 111 to directly contact the second surface 320. This can improve the space utilization of the electrode assembly 11, thereby increasing the volumetric energy density of the battery cell 10, and thus facilitating the improvement of the volumetric energy density of the battery device 100.

[0135] According to some embodiments of this application, the first wall 31 and the second wall 32 are welded together.

[0136] In some embodiments, the first wall 31 and the second wall 32 can be joined together by a welding process. Exemplarily, during the welding process, the first wall 31 and the second wall 32 can be positioned first, and the welding head can weld the first wall 31 and the second wall 32 along the thickness direction z of the second wall or along the thickness direction of the first wall 31, so that the junction of the first wall 31 and the second wall 32 is fused together to form a weld mark. Optionally, when welding along the thickness direction z of the second wall, the weld mark can be formed on the side of the second wall 32 opposite to the electrode assembly 11. When welding along the thickness direction of the first wall 31, the weld mark can be formed on the side of the first wall 31 opposite to the electrode assembly 11.

[0137] In the above solution, the two independent structures, the first wall 31 and the second wall 32, are welded together, so that there is no inner rounded corner between the first wall 31 and the second wall 32. On the one hand, this can improve the problem of interference to the electrode assembly 11 at the junction of the first wall 31 and the second wall 32, reduce the problem of damage to the electrode assembly 11 structure and affect the reliability of the battery. On the other hand, it can eliminate the bottom support plate in related technologies, thereby improving the space utilization of the electrode assembly 11, so as to improve the volumetric energy density of the battery cell 10, which in turn is conducive to improving the volumetric energy density of the battery device 100. Furthermore, the welding process is simple, the connection is reliable and the manufacturing efficiency is high, which is conducive to improving the manufacturing efficiency of the battery device 100.

[0138] In some other embodiments of this application, the first wall 31 and the second wall 32 can be bonded together as a single unit.

[0139] According to some embodiments of this application, please refer to Figure 4. The surface of the third wall 33 facing the cavity is the third surface 330. The third surface 330 and the second surface 320 are directly connected and the connection area forms a second preset angle. The second preset angle is not less than 85° and not greater than 95°.

[0140] Along the first direction x, the third wall 33 and the first wall 31 are opposite to each other, and the third surface 330 is the surface of the third wall 33 facing the cavity. Optionally, the third surface 330 can be the inner surface of the third wall 33, that is, along the thickness direction of the third wall 33, the third surface 330 is the surface of the third wall 33 closest to the electrode assembly 11.

[0141] "The third surface 330 and the second surface 320 are directly connected and the connection area forms a second preset angle" can be understood as follows: the first surface 310 and the third surface 330 can be flat surfaces, and there is no transition between them through other parts, such as no inner rounded corner transition between the first surface 310 and the third surface 330, and the angle between the first surface 310 and the third surface 330 is the second preset angle. Optionally, referring to Figure 4, the flat first surface 310 and the flat third surface 330 are directly connected, and the second preset angle between the first surface 310 and the third surface 330 is 90° or close to 90°. For example, referring to Figure 4, the second preset angle between the first surface 310 and the third surface 330 is R2. The value of R2 can be a value that is not less than 85° and not greater than 95°, such as 85°, 86°, 87°, 88°, 89°, 90°, 91°, 92°, 93°, 94°, 95° or any value between two adjacent values.

[0142] In some embodiments, the third wall 33 and the second wall 32 can be separate structures that are spliced ​​together to form a single unit, such that the first surface 310 and the third surface 330 are directly connected and the connection area forms a second preset angle. Optionally, when manufacturing the outer shell 30, the second wall 32 is a plate-like structure, and the third wall 33 is positioned at the edge of the second wall 32. The first wall 31 and the third wall 33 are combined into one unit by a connection process, such as by welding, bonding or other processes, so that there is no inner rounded corner between the third wall 33 and the second wall 32.

[0143] In the above solution, by setting the third surface 330 of the third wall 33 to be directly connected to the second surface 320 of the second wall 32, and making the second preset included angle between the third surface 330 and the second surface 320 a right angle or an angle close to a right angle, the risk of the electrode assembly 11 being damaged due to the interference of the inner rounded corner between the third wall 33 and the second wall 32 on the electrode assembly 11, resulting in a decrease in the reliability of the battery cell 10, can be effectively improved.

[0144] In some other embodiments of this application, the third wall 33 and the second wall 32 can be an integral structure; optionally, the third wall 33 is bent from the second wall 32. Optionally, the third wall 33 and the second wall 32 are formed by die casting.

[0145] According to some embodiments of this application, the third wall 33 and the second wall 32 are welded together.

[0146] In some embodiments, the third wall 33 and the second wall 32 can be integrally connected by a welding process. Exemplarily, during the welding process, the third wall 33 and the second wall 32 can be positioned first. The welding head can weld the second wall 32 and the third wall 33 along the thickness direction z of the second wall or along the thickness direction of the third wall 33, so that the junction of the second wall 32 and the third wall 33 is fused together to form a weld mark. Optionally, when welding along the thickness direction z of the second wall, the weld mark can be formed on the side of the second wall 32 opposite to the electrode assembly 11. When welding along the thickness direction of the third wall 33, the weld mark can be formed on the side of the third wall 33 opposite to the electrode assembly 11.

[0147] In the above solution, the two independent structures, the third wall 33 and the second wall 32, are welded together, so that there is no inner rounded corner between the third wall 33 and the second wall 32. On the one hand, this can improve the problem of interference to the electrode assembly 11 at the junction of the third wall 33 and the second wall 32, reduce the problem of damage to the electrode assembly 11 structure and affect the reliability of the battery. On the other hand, it can eliminate the bottom support plate in related technologies, thereby improving the space utilization of the electrode assembly 11, so as to improve the volumetric energy density of the battery cell 10, which in turn is conducive to improving the volumetric energy density of the battery device 100. Furthermore, the welding process is simple, the connection is reliable and the manufacturing efficiency is high, which is conducive to improving the manufacturing efficiency of the battery device 100.

[0148] In some other embodiments of this application, the third wall 33 is adhered to the second wall 32.

[0149] According to some embodiments of this application, please refer to Figures 3 and 5. Figure 5 is a schematic diagram of the structure of the fourth wall 34, the fifth wall 35 and the second wall 32 in some embodiments of this application.

[0150] The outer casing 30 also includes a fourth wall 34 and a fifth wall 35, which are opposite to each other along the second direction y, and perpendicular to each other in the first direction x and the second direction y. The surface of the fourth wall 34 facing the cavity is the fourth surface 340, which is directly connected to the second surface 320, and the connection area forms a third preset angle, which is not less than 85° and not greater than 95°; and / or the surface of the fifth wall 35 facing the cavity is the fifth surface 350, which is directly connected to the second surface 320, and the connection area forms a fourth preset angle, which is not less than 85° and not greater than 95°.

[0151] The fourth wall 34 and the fifth wall 35 are two wall portions of the outer casing 30 that are opposite to each other along the second direction y. In some embodiments, the first direction x can be the thickness direction of the battery cell 10, the second direction y can be the width direction of the battery cell 10, the first wall 31 and the third wall 33 can be the large surface of the outer casing 30, and the fourth wall 34 and the fifth wall 35 can be two side walls located between the first wall 31 and the third wall 33.

[0152] In some embodiments, the second wall 32 may be square, with the first wall 31 and the third wall 33 respectively disposed on the two long sides of the second wall 32, and the fourth wall 34 and the fifth wall 35 respectively disposed on the two short sides of the second wall 32.

[0153] In some embodiments, the fourth surface 340 is the surface of the fourth wall 34 facing into the cavity. Optionally, the fourth surface 340 can be the inner surface of the fourth wall 34, that is, along the thickness direction of the fourth wall 34, the fourth surface 340 is the surface of the fourth wall 34 closest to the electrode assembly 11.

[0154] In one embodiment, the fifth surface 350 is the surface of the fifth wall 35 facing the cavity. Optionally, the fifth surface 350 can be the inner surface of the fifth wall 35, that is, along the thickness direction of the fifth wall 35, the fifth surface 350 is the surface of the fifth wall 35 closest to the electrode assembly 11.

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

[0156] "The fifth surface 350 and the second surface 320 are directly connected, and the connection area forms a fourth preset angle," can be understood as follows: the fifth surface 350 and the second surface 320 can be flat surfaces, and there is no transition between them through other parts, such as no inner rounded corner transition between the fifth surface 350 and the second surface 320, and the angle between the fifth surface 350 and the second surface 320 is the fourth preset angle. Optionally, referring to Figure 5, the flat fifth surface 350 and the flat second surface 320 are directly connected, and the fourth preset angle between the fifth surface 350 and the second surface 320 is 90° or close to 90°. For example, referring to Figure 5, the fourth preset angle between the fourth surface 340 and the second surface 320 is R3. The value of R3 can be a value that is not less than 85° and not greater than 95°, such as 85°, 86°, 87°, 88°, 89°, 90°, 91°, 92°, 93°, 94°, 95°, or any value between two adjacent values.

[0157] In some embodiments, the first wall 31 and the fourth wall 34 can be separate structures that are spliced ​​together to form a single unit, such that the first surface 310 and the fourth surface 340 are directly connected and the connection area forms a third preset angle. Optionally, when manufacturing the outer shell 30, the second wall 32 is a plate-like structure, and the fourth wall 34 is positioned at the edge of the second wall 32. The first wall 31 and the fourth wall 34 are combined into one unit by a connection process, such as by welding, bonding or other processes, so that there is no inner rounded corner between the first wall 31 and the fourth wall 34.

[0158] In some embodiments, the first wall 31 and the fifth wall 35 can be separate structures that are spliced ​​together to form a single unit, such that the first surface 310 and the fifth surface 350 are directly connected and the connection area forms a fourth preset angle. Optionally, when manufacturing the outer shell 30, the second wall 32 is a plate-like structure, and the fifth wall 35 is positioned at the edge of the second wall 32. The first wall 31 and the fifth wall 35 are combined into one unit by a connection process, such as by welding, bonding or other processes, so that there is no inner rounded corner between the first wall 31 and the fifth wall 35.

[0159] In some embodiments, the second wall 32, the fourth wall 34, and the fifth wall 35 can be separate structures. In other embodiments of this application, the second wall 32 and the fourth wall 34 can be an integral structure, formed by casting, die casting, or bending. In other embodiments of this application, the second wall 32 and the fifth wall 35 can be an integral structure, formed by casting, die casting, or bending. In other embodiments of this application, the second wall 32, the fourth wall 34, and the fifth wall 35 can be an integral structure, formed by casting, die casting, or other processes. In other embodiments of this application, the second wall 32, the third wall 33, the fourth wall 34, and the fifth wall 35 can be an integral structure, formed by casting, die casting, or other processes.

[0160] In the above scheme, by setting the fourth surface 340 of the fourth wall 34 to be directly connected to the second surface 320 of the second wall 32, and making the third preset included angle between the fourth surface 340 and the second surface 320 a right angle or an angle close to a right angle, the risk of the electrode assembly 11 being damaged due to interference from the inner rounded corner between the fourth wall 34 and the second wall 32, resulting in a decrease in the reliability of the battery cell 10, can be reduced, thereby effectively improving the reliability of the battery device 100. At the same time, by setting the fifth surface 350 of the fifth wall 35 to be directly connected to the second surface 320 of the second wall 32, and making the fourth preset included angle between the fifth surface 350 and the second surface 320 a right angle or an angle close to a right angle, the risk of the electrode assembly 11 being damaged due to interference from the inner rounded corner between the fifth wall 35 and the second wall 32, resulting in a decrease in the reliability of the battery cell 10, can be reduced, thereby effectively improving the reliability of the battery device 100.

[0161] According to some embodiments of this application, the fourth wall 34 and the second wall 32 are welded together; and / or the fifth wall 35 and the second wall 32 are welded together.

[0162] In some embodiments, the fourth wall 34 and the second wall 32 can be integrally connected by a welding process. Exemplarily, during the welding process, the fourth wall 34 and the second wall 32 can be positioned first, and the welding head can weld the fourth wall 34 and the second wall 32 along the thickness direction z of the second wall or along the thickness direction of the fourth wall 34, so that the fourth wall 34 and the second wall 32 are fused together at their interface to form a weld mark. Optionally, when welding along the thickness direction z of the second wall, the weld mark can be formed on the side of the second wall 32 opposite to the electrode assembly 11. When welding along the thickness direction of the fourth wall 34, the weld mark can be formed on the side of the fourth wall 34 opposite to the electrode assembly 11.

[0163] In some embodiments, the fifth wall 35 and the second wall 32 can be integrally connected by a welding process. Exemplarily, during the welding process, the fifth wall 35 and the second wall 32 can be positioned first, and the welding head can weld the fifth wall 35 and the second wall 32 along the thickness direction z of the second wall or along the thickness direction of the fifth wall 35, so that the fifth wall 35 and the second wall 32 are fused together at their interface to form a weld mark. Optionally, when welding along the thickness direction z of the second wall, the weld mark can be formed on the side of the second wall 32 opposite to the electrode assembly 11. When welding along the thickness direction of the fifth wall 35, the weld mark can be formed on the side of the fifth wall 35 opposite to the electrode assembly 11.

[0164] In the above solution, the two independent structures, fourth wall 34 and second wall 32, are welded together, and the two independent structural lines, fifth wall 35 and second wall 32, are welded together. This eliminates the need for internal rounded corners between fourth wall 34 and second wall 32, and between fifth wall 35 and second wall 32. On the one hand, this improves the interference of the junctions of fourth wall 34 and second wall 32, and fifth wall 35 and second wall 32, on the electrode assembly 11, reducing structural damage to the electrode assembly 11 and its impact on battery reliability. On the other hand, it eliminates the need for a base plate in related technologies, thereby improving the space utilization of the electrode assembly 11 and increasing the volumetric energy density of the battery cell 10, which in turn benefits the improvement of the volumetric energy density of the battery device 100. Furthermore, the welding process is simple, the connection is reliable, and the manufacturing efficiency is high, which is beneficial to improving the manufacturing efficiency of the battery device 100.

[0165] According to some embodiments of this application, the outer shell 30 includes a shell 30a, which is an integral structure. The shell 30a includes a first wall 31, a third wall 33, a fourth wall 34, and a fifth wall 35. Along the thickness direction z of the second wall, one end of the shell 30a has a first opening 30b, and the second wall 32 closes the first opening 30b.

[0166] In some embodiments, the housing 30 includes a housing 30a and a second wall 32. The housing 30a is an integral structure with a first opening 30b. The second wall 32 and the housing 30a are separate structures that are joined together by a connection process, for example, the housing 30a is connected to the edge of the second wall 32 by welding, and the second wall 32 can close the first opening 30b.

[0167] For example, when assembling the battery cell 10, the electrode assembly 11 can be inserted into the interior of the housing 30a through the first opening 30b, and then the second wall 32 is connected to the housing 30a to cover the first opening 30b, so that the electrode assembly 11 is in a closed space. Finally, the electrolyte is injected into the closed space through the injection hole on the housing 30 and the injection hole is sealed.

[0168] Alternatively, when assembling the battery cell 10, the electrode assembly 11 and the electrolyte can be disposed inside the housing 30a through the first opening 30b, and then the second wall 32 is connected to the housing 30a to cover the first opening 30b, thereby placing the electrode terminal 12 and the electrolyte in a closed space.

[0169] Optionally, please refer to Figure 6, which is an exploded perspective view of the outer casing 30 in some embodiments of this application. The casing 30a is an integral structure and can be formed by processes such as casting, bending, and welding. During the assembly of the battery cell 10, the casing 30a is supplied as a whole to connect with the second wall 32. The casing 30a includes a first wall 31, a third wall 33, a fourth wall 34, and a fifth wall 35. Along the circumference of the outer casing 30, the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 are connected end to end to form a cylindrical structure. One end of the casing 30a forms a first opening 30b, and the other end forms a second opening 30c. The second wall 32 closes the first opening 30b, and the second opening 30c is closed by the sixth wall 36.

[0170] Optionally, please refer to Figure 7, which is an exploded perspective view of the outer shell 30 in some other embodiments of this application. The shell 30a is an integral structure, which can be integrally formed by casting, die casting, or stamping. The shell 30a includes a first wall 31, a third wall 33, a fourth wall 34, a fifth wall 35, and a sixth wall 36. Along the circumference of the outer shell 30, the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 are connected end to end and are disposed around the edge of the sixth wall 36. A first opening 30b is formed at the end of the shell 30a opposite to the sixth wall 36, and the second wall 32 closes the first opening 30b.

[0171] In the above scheme, the integrated housing 30a includes a first wall 31, a third wall 33, a fourth wall 34, and a fifth wall 35. By connecting the second wall 32 to the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 respectively, the first opening 30b of the housing 30a can be closed to support the electrode assembly 11 or to provide a closed space for the electrode assembly 11. On the other hand, the junction between the housing 30a and the second wall 32 is free of inner rounded corners, thereby reducing the interference of the housing 30a on the electrode assembly 11. This eliminates the need for a bottom support plate in related technologies, thus balancing the reliability of the battery cell 10 and the improvement of energy density. Furthermore, during the manufacturing process, the assembly of the integrated housing 30a and the first wall 31 is less difficult, resulting in high manufacturing efficiency for the battery cell 10 and consequently, high manufacturing efficiency for the battery device 100.

[0172] According to some embodiments of this application, please refer to FIG6, the housing 30 further includes a sixth wall 36, and along the thickness direction z of the second wall, the other end of the housing 30a has a second opening 30c, and the sixth wall 36 closes the second opening 30c.

[0173] The outer casing 30 includes a shell 30a, a sixth wall 36, and a second wall 32. The shell 30a is an integral structure. Along the thickness direction z of the second wall, one end of the shell 30a has a first opening 30b, and the other end has a second opening 30c. The second wall 32 is connected to one end of the shell 30a to close the first opening 30b, and the sixth wall 36 is connected to the other end of the shell 30a to close the second opening 30c.

[0174] Optionally, the second wall 32 may be welded to one end of the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35. Optionally, the sixth wall 36 may be welded to the other end of the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35.

[0175] In the above solution, the outer shell 30 includes a shell 30a, a sixth wall 36, and a second wall 32, which are separate structures and are connected to each other. On the one hand, this improves the problem that interference at the junction of the shell 30a and the second wall 32 with the electrode assembly 11 causes damage to the structure of the electrode assembly 11 and affects the reliability of the battery cell 10. On the other hand, it can reduce the molding difficulty of the outer shell 30 and reduce the manufacturing cost of the battery cell 10 during the manufacturing and assembly process of the battery cell 10.

[0176] According to some embodiments of this application, please refer to FIG6, along the circumference of the outer casing 30, the opposite ends of the fourth wall 34 are bent at the first wall 31 and the third wall 33, respectively. Along the circumference of the outer casing 30, the fifth wall 35 includes a first portion 351 and a second portion 352, the first portion 351 is bent at the first wall 31, the second portion 352 is bent at the third wall 33, and the first portion 351 and the second portion 352 are welded together.

[0177] In some embodiments, the outer casing 30 may be constructed by bending and welding a plate-like structural member. For example, the outer casing 30 may be constructed by bending a steel sheet to form a first portion 351, a first wall 31, a fourth wall 34, a third wall 33, and a second portion 352. The first portion 351 and the second portion 352 may be joined together by welding to form a fifth wall 35. Please refer to Figure 6, which shows the weld mark C formed by welding the first portion 351 and the second portion 352.

[0178] In the above scheme, a plate-like structure can be bent to form a shell-like structure, and the first part 351 and the second part 352 can be connected to each other by welding to form the shell 30a. That is, the shell 30a can be manufactured through a bending process and a welding process, which makes the manufacturing process of the shell 30a simple and fast, which is conducive to improving the manufacturing efficiency of the battery cell 10, and thus conducive to improving the manufacturing efficiency of the battery device 100.

[0179] In other embodiments, the housing 30a can also be manufactured by a casting process.

[0180] According to some other embodiments of this application, please refer to FIG7, the housing 30a further includes a sixth wall 36. Along the circumference of the housing 30, the first wall 31, the third wall 33, the fourth wall 34 and the fifth wall 35 surround the edge of the sixth wall 36. Along the thickness direction of the second wall 32, the sixth wall 36 and the second wall 32 are opposite to each other.

[0181] The outer shell 30 includes a shell 30a and a second wall 32, which are separate structures. The shell 30a is an integral structure, which includes a first wall 31, a third wall 33, a fourth wall 34, a fifth wall 35 and a sixth wall 36. The first wall 31, the third wall 33, the fourth wall 34 and the fifth wall 35 surround the edge of the sixth wall 36 to form a first opening 30b at one end of the shell 30a. The second wall 32 closes the first opening 30b.

[0182] In some embodiments, the housing 30a may be formed by casting, die casting or stamping processes.

[0183] In the above scheme, the housing 30a, which is an integral structure, includes a sixth wall 36 and a first wall 31, a third wall 33, a fourth wall 34, and a fifth wall 35 surrounding the edge of the sixth wall 36. This makes the housing 30a a cylindrical structure that is closed at one end and open at the other. On the one hand, this facilitates the assembly of the electrode assembly 11, reduces the assembly process of the battery cell 10, and improves the manufacturing efficiency of the battery device 100. On the other hand, it reduces the number of connection interfaces on the surface of the housing 30, which improves the airtightness of the battery cell 10, improves the reliability of the battery cell 10, and thus improves the reliability of the battery device 100.

[0184] According to some other embodiments of this application, see FIG7, electrode terminal 12 is disposed on the sixth wall 36.

[0185] In some embodiments, the battery cell 10 is placed vertically, the second wall 32 can be the bottom wall of the housing 30, which has the function of supporting the electrode assembly 11, and the sixth wall 36 can be the top wall of the housing 30, which can serve to install the electrode terminal 12.

[0186] In some embodiments, the first electrode terminal 12a and the second electrode terminal 12b are respectively disposed on the sixth wall 36.

[0187] In some embodiments, when assembling the battery cell 10, the electrode terminal 12 is mounted on the sixth wall 36, and the electrode assembly 11 can be disposed inside the housing 30a through the first opening 30b, connecting the electrode terminal 12 to the tab of the electrode assembly 11, and then connecting the second wall 32 to the housing 30a to cover the first opening 30b.

[0188] In the above scheme, by setting the electrode terminal 12 at the sixth end to connect with the tab lead-out end of the electrode assembly 11, the second wall 32 can contact the other end of the electrode terminal 12 without being interfered with by the junction of the second wall 32 and the housing 30a. This eliminates the need for the bottom support plate in the related technology, thereby improving the volumetric energy density of the battery cell 10 and the volumetric energy density of the battery device 100.

[0189] According to some other embodiments of this application, the first wall 31, the third wall 33, the fourth wall 34 and the fifth wall 35 are separate structures. The opposite ends of the fourth wall 34 along the second direction y are respectively welded to the first wall 31 and the third wall 33, and the opposite ends of the fifth wall 35 along the second direction y are respectively welded to the first wall 31 and the third wall 33.

[0190] In some embodiments, the outer shell 30 may be assembled from multiple split structures, for example, the outer shell 30 may be welded together from multiple steel plates.

[0191] Optionally, the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 are each independent plate-like structures. The opposite ends of the fourth wall 34 along the second direction y are welded to the first wall 31 and the third wall 33, respectively. The opposite ends of the fifth wall 35 along the second direction y are welded to the first wall 31 and the third wall 33, respectively. Along the thickness direction z of the second wall, one end of the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 are welded to the second wall 32, and the other end of the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 are welded to the sixth wall 36, respectively.

[0192] In the above scheme, the outer shell 30 is composed of multiple split structures welded together, which can effectively reduce the interference of the connection interface between the inner walls of the outer shell 30 on the electrode assembly 11, which is conducive to improving the space utilization of the battery assembly, thereby improving the volumetric energy density of the battery cell 10, and further improving the volumetric energy density of the battery device 100.

[0193] According to some embodiments of this application, along the thickness direction z of the second wall, electrode terminals 12 are disposed on the wall portion of the housing 30 opposite to the second wall 32.

[0194] In some embodiments, along the thickness direction z of the second wall, the second wall 32 is disposed on one side of the electrode assembly 11, and the first electrode terminal 12a and the second electrode terminal 12b are disposed on the other side of the electrode assembly 11.

[0195] Optionally, along the thickness direction z of the second wall, the housing 30 includes a second wall 32 and a sixth wall 36 opposite to each other, with the electrode terminal 12 disposed on the sixth wall 36. In some embodiments, the sixth wall 36 can be a separate structure, for example, the sixth wall 36 is plate-shaped, with the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 surrounding the edge of the sixth wall 36. Alternatively, the sixth wall 36 can be part of the structure of the housing 30a, which is an integral structure including the first wall 31, the third wall 33, the fourth wall 34, the fifth wall 35, and the sixth wall 36.

[0196] In the above scheme, the electrode terminal 12 is disposed on the side of the housing 30 away from the second wall 32, that is, the electrode assembly 11 is a single-sided electrode tab, which can reduce the space occupied by the electrode terminal 12 and the electrode assembly 11 in the thickness direction z of the second wall, which is beneficial to the improvement of the volumetric energy density of the battery cell 10 and the battery device 100.

[0197] According to other embodiments of this application, please refer to FIG8, which is a schematic diagram of the battery cell 10 in other embodiments of this application. The electrode terminal 12 is disposed on the wall portion of the housing 30 along the second direction y, and the first direction x, the second direction y, and the thickness direction z of the second wall are perpendicular to each other.

[0198] In some embodiments, electrode terminals 12 are disposed on the wall portion of the housing 30 along the second direction y. For example, the first electrode terminal 12a and the second electrode terminal 12b are respectively disposed on the fourth wall 34 and the fifth wall 35 of the housing 30 that are opposite to each other along the second direction y; or the first electrode terminal 12a and the second terminal are respectively disposed on the fourth wall 34.

[0199] Optionally, the outer casing 30 is blade-shaped, with the first direction x being the thickness direction of the outer casing 30 and the second direction y being the length direction of the outer casing 30. The dimension of the outer casing 30 in the second direction y is greater than the dimension in the first direction x, and the dimension of the outer casing 30 in the second direction y is greater than the dimension in the thickness direction z of the second wall.

[0200] In the above solution, by setting the electrode terminal 12 on the wall of the housing 30 along the second direction y, the space occupied by the electrode terminal 12 and the electrode assembly 11 in the thickness direction z and the first direction x of the second wall can be reduced, which is beneficial to improving the volumetric energy density of the battery cell 10 and the volumetric energy density of the battery device 100. In related technologies, especially in blade batteries, the surface of the housing 30 along the second direction y is the side surface (small surface). By setting the electrode terminal 12 on the side surface, the high volumetric energy density of the blade battery can be fully utilized to further improve the volumetric energy density of the battery device 100.

[0201] According to some other embodiments of this application, the electrode terminal 12 includes a first electrode terminal 12a and a second electrode terminal 12b with opposite polarities. The first electrode terminal 12a is disposed on one wall of the housing 30 along the second direction y, and the second electrode terminal 12b is disposed on another wall of the housing 30 along the second direction y.

[0202] In some embodiments, along the second direction y, the housing 30 includes a fourth wall 34 and a fifth wall 35 opposite to each other, a first electrode terminal 12a may be disposed on the fourth wall 34, and a second electrode terminal 12b may be disposed on the fifth wall 35.

[0203] In the above scheme, by setting the first electrode terminal 12a and the second electrode terminal 12b with opposite polarities on two opposite walls of the housing 30 along the second direction y, the negative electrode charge state distribution can be made more uniform, thereby reducing the risk of lithium plating, effectively reducing the risk of internal short circuit and heat generation in the battery cell 10, improving the reliability of the battery cell 10, and contributing to the improvement of the reliability of the battery device 100.

[0204] According to some embodiments of this application, the outer shell 30 is made of steel, and the thickness of the outer shell 30 is not less than 0.075 mm and not more than 0.3 mm.

[0205] In some embodiments, the outer casing 30 is made of steel, for example, the first wall 31, the second wall 32, the third wall 33, the fourth wall 34, the fifth wall 35 and the sixth wall 36 are all made of steel.

[0206] In some embodiments, the thickness of the outer shell 30 is not less than 0.075 mm and not more than 0.3 mm. For example, the thickness of the outer shell 30 can be 0.075 mm, 0.080 mm, 0.085 mm, 0.090 mm, 0.095 mm, 0.1 mm, 0.105 mm...0.295 mm, 0.3 mm or any value between two adjacent values.

[0207] In some embodiments, the thickness of the housing 30 can be measured by means or devices such as a size measuring instrument or a laser rangefinder.

[0208] In the above scheme, the outer shell 30 is made of steel with high structural strength. With the battery cell 10 having a large overall structural strength, the wall thickness of the outer shell 30a can be greatly reduced. For example, the thickness of the outer shell 30 is limited to not less than 0.075mm and not more than 0.3mm, thereby reducing the proportion of the outer shell 30a in the battery cell 10, and thus enabling the battery cell 10 to have a higher volumetric energy density, which is beneficial to improving the volumetric energy density of the battery device 100.

[0209] According to some embodiments of this application, please refer to FIG9, which is an enlarged view of point A in FIG4.

[0210] The first wall 31 and the second wall 32 are connected by a first connecting part 13. The first surface 310 contacts the outer peripheral surface of the second wall 32. Along the first direction x, the first connecting part 13 is located between the outer peripheral surfaces of the first surface 310 and the second wall 32, and a portion of the first connecting part 13 is located on the side of the second wall 32 away from the receiving cavity.

[0211] In some embodiments, the first wall 31 and the second wall 32 are welded together, and the first connecting portion 13 can be a weld mark formed by welding the first wall 31 and the second wall 32 together. Referring to FIG9, the outer peripheral surface of the second wall 32 can be adjacent to the first surface 310 of the first wall 31, and the first connecting portion 13 can be located between the outer peripheral surfaces of the first surface 310 and the second wall 32, and partially exposed on the side of the second wall 32 away from the electrode assembly 11.

[0212] Optionally, the second wall 32 is generally flat and is located between the first wall 31 and the third wall 33. The second wall 32 abuts against the first surface 310 on one side along the first direction x and against the third surface 330 on the other side along the first direction x. The welding head is welded to the junction of the first wall 31 and the second wall 32 along the direction from the second wall 32 to the sixth wall 36 to form the first connection part 13.

[0213] In the above scheme, the first surface 310 is connected to the second wall 32 through the first connecting part 13 and the outer peripheral surface of the first surface 310 is in contact with the second wall 32. With part of the first connecting part 13 located on the side of the second wall 32 away from the receiving cavity, the connection between the first wall 31 and the second wall 32 is easy. For example, welding the junction of the first wall 31 and the second wall 32 from the side of the first wall 31 away from the receiving cavity can effectively improve the connection efficiency of the first wall 31 and the second wall 32, thereby improving the manufacturing efficiency of the battery cell 10.

[0214] According to some embodiments of this application, the first connection portion 13 includes a solder mark formed between the first wall 31 and the second wall 32.

[0215] In some embodiments, the first wall 31 and the second wall 32 are welded together, and the first connecting part 13 can be a weld mark formed by welding the first wall 31 and the second wall 32 together.

[0216] In the above scheme, the first wall 31 and the second wall 32 are combined into one by welding process, and a weld mark is formed between them, which can effectively improve the connection reliability between the first wall 31 and the second wall 32, reduce the risk of separation between them, and make the battery cell 10 have high reliability, which is conducive to improving the reliability of the battery device 100.

[0217] In some other embodiments of this application, the first wall 31 and the second wall 32 can also be bonded together, and the first connecting part 13 may include an adhesive structure formed between the first wall 31 and the second wall 32.

[0218] According to some other embodiments of this application, please refer to Figures 10 and 11. Figure 10 is a structural schematic diagram of the first wall 31, the second wall 32 and the third wall 33 in some other embodiments of this application, and Figure 11 is an enlarged view of point B in Figure 10.

[0219] The first wall 31 and the second wall 32 are connected by a first connecting part 13. Along the thickness direction z of the second wall, a protrusion 321 is formed on the side of the second wall 32 facing the receiving cavity. The outer peripheral surface of the protrusion 321 contacts the first surface 310. Along the thickness direction z of the second wall, the first connecting part 13 is located between the end face of the first wall 31 and the second wall 32.

[0220] In some embodiments, the first wall 31 and the second wall 32 are welded together, and the first connecting part 13 can be a weld mark formed by welding the first wall 31 and the second wall 32 together.

[0221] Please refer to Figure 11. The second wall 32 may include a body 322 and a protrusion 321 arranged along its thickness direction. The protrusion 321 protrudes from the surface of the body 322 facing the electrode assembly 11. The first surface 310 of the first wall 31 abuts against the outer peripheral surface of the protrusion 321. The end of the first wall 31 abuts against the surface of the body 322 facing the electrode assembly 11. The first connecting portion 13 is formed between the end of the first wall 31 and the body.

[0222] Optionally, the second wall 32 is formed by stamping to form a body 322 and a protrusion 321. The protrusion 321 is located between the first wall 31 and the third wall 33, and one side of the protrusion 321 abuts against the first surface 310 along the first direction x, and the other side of the protrusion 321 abuts against the third surface 330 along the first direction x. The ends of the first wall 31 and the third wall 33 abut against the surface of the body 322 respectively. The welding head is welded to the part at the junction of the first wall 31 and the second wall 32 along the direction from the first wall 31 to the third wall 33 to form the first connecting part 13.

[0223] In the above solution, by providing a protrusion on the side of the second wall 32 facing the receiving cavity, the second wall 32 and the first wall 31 can be positioned relative to each other, which can reduce the risk of misalignment between the second wall 32 and the first wall 31, thereby improving the connection reliability of the first wall 31 and the second wall 32 and improving the structural reliability of the battery cell 10.

[0224] According to some embodiments of this application, the first connection portion 13 includes a solder mark formed between the first wall 31 and the second wall 32.

[0225] In some embodiments, the first wall 31 and the second wall 32 are welded together, and the first connecting part 13 can be a weld mark formed by welding the first wall 31 and the second wall 32 together.

[0226] In the above scheme, the first wall 31 and the second wall 32 are combined into one by welding process, and a weld mark is formed between them, which can effectively improve the connection reliability between the first wall 31 and the second wall 32, reduce the risk of separation between them, and make the battery cell 10 have high reliability, which is conducive to improving the reliability of the battery device 100.

[0227] In some other embodiments of this application, the first wall 31 and the second wall 32 can also be bonded together, and the first connecting part 13 may include an adhesive structure formed between the first wall 31 and the second wall 32.

[0228] According to some embodiments of this application, a battery device 100 is also provided, which includes the battery cell 10 described above.

[0229] Please refer to Figure 2. The battery device 100 includes a battery cell 10 and a housing 20, with the battery cell 10 housed within the housing 20.

[0230] Optionally, the housing 20 is provided with multiple battery cell assemblies, each battery cell assembly including multiple stacked battery cells 10, and the multiple battery cells 10 are connected in series via a busbar. In some embodiments, the multiple battery cell assemblies can be connected in series via a busbar.

[0231] According to some embodiments of this application, an electrical device is also provided, which includes the battery cell 10 and / or the battery device 100 provided above. The battery cell 10 and / or the battery device 100 provided above are used to provide electrical energy.

[0232] Optionally, the electrical device is a vehicle 1000, and the battery cell 10 can be used as a driving power source and / or control power source for the vehicle 1000.

[0233] According to some embodiments of this application, a battery cell 10 is provided. Referring to Figures 3-11, the battery cell 10 includes a housing 30, an electrode assembly 11, and electrode terminals 12. The housing 30 is a steel shell with a thickness of not less than 0.15 mm and not more than 0.25 mm. The electrode assembly 11 is disposed within the receiving cavity of the housing 30, and the electrode terminals 12 are disposed on the wall of the housing 30 and electrically connected to the electrode assembly 11. The electrode terminals 12 may include a first electrode terminal 12a and a second electrode terminal 12b with opposite polarities.

[0234] The outer casing 30 is a square casing 30, including a first wall 31, a second wall 32, a third wall 33, a fourth wall 34, a fifth wall 35, and a sixth wall 36. The first wall 31 and the third wall 33 are opposite each other along a first direction x, the fourth wall 34 and the fifth wall 35 are opposite each other along a second direction y, and the second wall 32 and the sixth wall 36 are opposite each other along the thickness direction z of the second wall. The first wall 31 and the third wall 33 are the larger surfaces of the outer casing 30, meaning the outer surfaces of the first wall 31 and the third wall 33 have the largest surface areas. In some embodiments of the battery cell 10 provided in this application, no base plate is provided between the electrode assembly 11 and the second wall 32, and the insulating film 111 covering the outer periphery of the main body 110 of the electrode assembly 11 can directly contact the second wall 32.

[0235] In some embodiments of this application, the second wall 32 is at least an independent structure from the first wall 31. For example, the second wall 32 is an independent structural component, and the first wall 31 is an independent structural component, both of which are welded together with other walls of the outer casing 30. For example, the second wall 32 is an independent structural component, while the first wall 31 is an integral structure with some other walls of the outer casing 30. The first wall 31 and the second wall 32 are connected to each other by welding, so that there is no inner rounded corner at the junction of the second wall 32 and a large surface of the outer casing 30.

[0236] In some embodiments of this application, the second wall 32 and the first wall 31 are independent structures, and the second wall 32 and the third wall 33 are independent structures. The second wall 32 is connected to the first wall 31 and the third wall 33 by welding, so that there is no inner rounded corner at the junction of the second wall 32 and the large surface of the outer shell 30.

[0237] In some embodiments of this application, the second wall 32 and the first wall 31 are independent structures, the second wall 32 and the third wall 33 are independent structures, the second wall 32 and the fourth wall 34 are independent structures, and the second wall 32 and the fifth wall 35 are independent structures. The second wall 32 is connected to the first wall 31, the third wall 33, the fourth wall 34 and the fifth wall 35 by welding, so that there are no inner rounded corners at the junction of the second wall 32 and other walls of the outer shell 30.

[0238] Optionally, referring to Figures 3 and 6, the outer casing 30 includes a casing 30a, a second wall 32, and a sixth wall 36. The casing 30a is an integral structure, comprising an integrated first wall 31, a third wall 33, a fourth wall 34, and a fifth wall 35. The casing 30a can be formed by processes such as casting and bending. For example, the casing 30a can be formed from a single sheet of steel through a bending process, creating the first wall 31, the third wall 33, the fourth wall 34, a first portion 351, and a second portion 352. The first portion 351 and the second portion 352 are welded together to form the fifth wall 35, and the first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 are connected integrally to form the casing 30a. One end of the casing 30a forms a first opening 30b, and the other end forms a second opening 30c. The second wall 32 is connected to the casing 30a and closes the first opening 30b, while the sixth wall 36 closes the second opening 30c. The first electrode terminal 12a and the second electrode terminal 12b can be respectively disposed on the sixth wall 36. In some embodiments, the surface of the sheet steel may be pre-formed with fold lines so that it can be bent along the fold lines, thereby improving bending efficiency.

[0239] The edge of the sixth wall 36 can be welded to the first wall 31, the third wall 33, the fourth wall 34 and the fifth wall 35 respectively.

[0240] Please refer to Figures 4 and 5. The two long sides of the second wall 32, which are opposite each other along the first direction x, are welded to the first wall 31 and the third wall 33, respectively. The two short sides of the second wall 32, which are opposite each other along the second direction y, are welded to the fourth wall 34 and the fifth wall 35, respectively.

[0241] The second surface 320 of the second wall 32 is directly connected to the first surface 310 of the first wall 31. There is no inner rounded corner between them, and the first preset included angle between them is not less than 85° and not greater than 95°, for example, the first preset included angle is 90°. The third surface 330 of the third wall 33 is directly connected to the first surface 310 of the first wall 31. There is no inner rounded corner between them, and the second preset included angle between them is not less than 85° and not greater than 95°, for example, the second preset included angle is 90°. The fourth surface 340 of the fourth wall 34 is directly connected to the first surface 310 of the first wall 31. There is no inner rounded corner between them, and the third preset included angle between them is not less than 85° and not greater than 95°, for example, the third preset included angle is 90°. The fifth surface 350 of the fifth wall 35 is directly connected to the first surface 310 of the first wall 31. There is no inner rounded corner between them, and the fourth preset included angle between them is not less than 85° and not greater than 95°, for example, the fourth preset included angle is 90°.

[0242] Optionally, referring to Figure 7, the housing 30 includes a housing 30a and a second wall 32. The housing 30a is an integral structure, including a first wall 31, a third wall 33, a fourth wall 34, a fifth wall 35, and a sixth wall 36 that are interconnected. The housing 30a can be integrally formed by casting, die casting, stamping, or other processes. One end of the housing 30a forms a first opening 30b, and the second wall 32 closes the first opening 30b, with the second wall 32 and the sixth wall 36 facing each other. In some embodiments, the first electrode terminal 12a and the second electrode terminal 12b can be respectively disposed on the sixth wall 36. In some embodiments, the two long sides of the second wall 32 opposite each other along the first direction x are welded to the first wall 31 and the third wall 33, respectively. The two short sides of the second wall 32 opposite each other along the second direction y are welded to the fourth wall 34 and the fifth wall 35, respectively.

[0243] Optionally, referring to Figure 8, the battery cell 10 can be blade-shaped, with its length direction greater than its thickness direction and its height direction. In some embodiments, along the length direction of the battery cell 10, the fourth wall 34 and the fifth wall 35 can be opposite each other; along the height direction of the battery cell 10, the second wall 32 and the sixth wall 36 can be opposite each other; and along the thickness direction of the battery cell 10, the first wall 31 and the third wall 33 can be opposite each other. The first electrode terminal 12a can be disposed on the fourth wall 34, and the second electrode terminal 12b can be disposed on the fifth wall 35. The first wall 31, the third wall 33, the fourth wall 34, and the fifth wall 35 can surround the second wall 32 and be welded to it respectively, so that there is no inner rounded corner at the junction of the housing 30a and the second wall 32, thereby eliminating the need for a base plate between the electrode assembly 11 and the second wall 32.

[0244] Optionally, in some embodiments, referring to FIG9, the second wall 32 may be in the form of a flat plate, and the outer peripheral surface of the second wall 32 may contact the first surface 310, the third surface 330, the fourth surface 340 and the fifth surface 350 respectively. The part of the second wall 32 that contacts the housing 30a can be welded from the outside of the second wall 32 (the side opposite to the electrode assembly 11), that is, the second wall 32 and the housing 30a are integrated into one body by bottom welding. In this welding method, taking the second wall 32 as the bottom wall as an example, the weld mark between the second wall 32 and the housing 30a is located at the bottom of the outer shell 30.

[0245] Optionally, in some embodiments, referring to FIG11, the second wall 32 may include a body 322 and a protrusion 321 arranged along its thickness direction. The protrusion 321 protrudes from the surface of the body 322 facing the electrode assembly 11. The outer peripheral surface of the protrusion 321 may contact the first surface 310, the third surface 330, the fourth surface 340 and the fifth surface 350 respectively. The ends of the first wall 31, the third wall 33, the fourth wall 34 and the fifth wall 35 may abut against the surface of the body 322 respectively. The part of the second wall 32 that contacts the housing 30a can be welded from the outside of the housing 30a (the side away from the electrode assembly 11), that is, the second wall 32 and the housing 30a are integrated into one body by side welding. In this welding method, taking the second wall 32 as the bottom wall as an example, the weld mark between the second wall 32 and the housing 30a is located on the side of the outer shell 30.

[0246] In the above scheme, there is no inner rounded corner at the junction of the second wall 32 and the housing 30a. Therefore, during the assembly process or the internal expansion process of the battery cell 10, the risk of interference between the electrode assembly 11 and the junction of the second wall 32 and the housing 30a is small, resulting in high reliability of the battery cell 10. At the same time, since there is no inner rounded corner, a bottom support plate is not required, thereby increasing the volumetric energy density of the battery cell 10 and thus increasing the volumetric energy density of the battery device 100.

[0247] 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, wherein, include: The outer shell has an internal cavity. The outer shell includes a first wall, a second wall, and a third wall. Along a first direction, the first wall and the third wall are disposed opposite to each other. The second wall is located between the first wall and the third wall and connects the first wall and the third wall. An electrode assembly is disposed within the receiving cavity; the electrode assembly has a stacked structure, and the first direction is the stacking direction of the electrode assembly; Alternatively, the electrode assembly is a wound structure, the electrode assembly includes a planar region located in the middle and corner regions located on both sides, and the first direction is the stacking direction of the electrode assembly in the planar region; Electrode terminals are disposed in the housing and electrically connected to the electrode assembly, and the electrode terminals are located in other walls of the housing other than the first wall, the second wall and the third wall; Wherein, the surface of the first wall facing the cavity is the first surface, and the surface of the second wall facing the cavity is the second surface. The first surface and the second surface are directly connected and the connection area forms a first preset angle, which is not less than 85° and not greater than 95°.

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

3. The battery cell according to claim 1 or 2, wherein, The first wall and the second wall are welded together.

4. The battery cell according to any one of claims 1-3, wherein, The surface of the third wall facing the cavity is called the third surface. The third surface and the second surface are directly connected and the connection area forms a second preset angle. The second preset angle is not less than 85° and not greater than 95°.

5. The battery cell according to claim 4, wherein, The third wall and the second wall are welded together.

6. The battery cell according to any one of claims 1-5, wherein, The outer casing also includes a fourth wall and a fifth wall, which are opposite to each other along the second direction, and the first direction and the second direction are perpendicular to each other; The fourth wall facing the cavity is the fourth surface, and the fourth surface and the second surface are directly connected and the connection area forms a third preset angle, which is not less than 85° and not greater than 95°; and / or, the fifth wall facing the cavity is the fifth surface, and the fifth surface and the second surface are directly connected and the connection area forms a fourth preset angle, which is not less than 85° and not greater than 95°.

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

8. The battery cell according to claim 6 or 7, wherein, The outer shell includes a housing, which is an integral structure. The housing includes a first wall, a third wall, a fourth wall, and a fifth wall. Along the thickness direction of the second wall, one end of the housing has a first opening, and the second wall closes the first opening.

9. The battery cell according to claim 8, wherein, The outer casing also includes a sixth wall, and along the thickness direction of the second wall, the other end of the casing has a second opening, the sixth wall closing the second opening.

10. The battery cell according to claim 9, wherein, Along the circumference of the outer shell, the opposite ends of the fourth wall are respectively bent at the first wall and the third wall; Along the circumference of the outer shell, the fifth wall includes a first portion and a second portion, the first portion being bent into the first wall and the second portion being bent into the third wall, the first portion and the second portion being welded together.

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

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

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

14. The battery cell according to any one of claims 1-13, wherein, Along the thickness direction of the second wall, the electrode terminals are disposed on the wall portion of the housing opposite to the second wall.

15. The battery cell according to any one of claims 1-13, wherein, The electrode terminals are disposed on the wall portion of the housing along the second direction, wherein the first direction, the second direction, and the thickness direction of the second wall are perpendicular to each other.

16. The battery cell according to claim 15, wherein, The electrode terminals include a first electrode terminal and a second electrode terminal with opposite polarities. The first electrode terminal is disposed on one wall portion of the housing along the second direction, and the second electrode terminal is disposed on another wall portion of the housing along the second direction.

17. The battery cell according to any one of claims 1-16, wherein, The outer shell is made of steel, and its thickness is not less than 0.075 mm and not more than 0.3 mm.

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

19. The battery cell according to any one of claims 1-18, wherein, The first wall and the second wall are connected by a first connecting portion. The first surface contacts the outer peripheral surface of the second wall. Along the first direction, the first connecting portion is located between the first surface and the outer peripheral surface of the second wall, and a portion of the first connecting portion is located on the side of the second wall opposite to the receiving cavity.

20. The battery cell according to claim 19, wherein, The first connection includes a solder mark formed between the first wall and the second wall.

21. The battery cell according to any one of claims 1-18, wherein, The first wall and the second wall are connected by a first connecting part. Along the thickness direction of the second wall, a protrusion is formed on the side of the second wall facing the receiving cavity. The outer peripheral surface of the protrusion contacts the first surface. Along the thickness direction of the second wall, the first connecting part is located between the end face of the first wall and the second wall.

22. The battery cell according to claim 21, wherein, The first connection includes a solder mark formed between the first wall and the second wall.

23. A battery device, wherein, Includes the battery cell as described in any one of claims 1-22.

24. An electrical appliance, wherein, Includes the battery cell according to any one of claims 1-22 and / or the battery device according to claim 23, wherein the battery cell is used to provide electrical energy.

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