Battery cell, battery and electric apparatus

Abstract

A battery cell (20), a battery (100) and an electric apparatus. The battery cell (20) comprises: a casing (21), the casing (21) having a plurality of wall portions (211), the plurality of wall portions (211) comprising first walls (201), each first wall (201) comprising a main body portion (2011) and an edge portion (2012) connected to the main body portion (2011), the edge portion (2012) being connected to adjacent wall portions (211), and the wall thickness of the edge portion (2012) being greater than the wall thickness of the main body portion (2011); an electrode assembly arranged in the casing (21); and electrode terminals arranged on the wall portions (211) and electrically connected to the electrode assembly.

Description

Battery cells, batteries and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number: 202322476888.3 and application date of September 12, 2023, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0004] New energy vehicles have experienced rapid growth in recent years. Within the electric vehicle sector, power batteries, as the power source, play an irreplaceable and important role. A battery consists of a housing and multiple cells housed within it. As a core component of new energy vehicles, batteries are subject to high safety and service life requirements. However, during use, the thin shell design of the cell structure can lead to insufficient reliability, which in turn affects battery reliability.

[0005] Summary of the Invention

[0006] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can effectively improve the reliability of the battery cell and the battery, thereby improving the performance of the battery cell and the battery.

[0007] In a first aspect, an embodiment of the present application provides a battery cell, comprising: a shell, the shell having multiple wall portions, the multiple wall portions including a first wall, the first wall including a main body portion and an edge portion connected to the main body portion, the edge portion being connected to an adjacent wall portion, and the wall thickness of the edge portion being greater than the wall thickness of the main body portion; an electrode assembly, the electrode assembly being arranged in the shell; and electrode terminals, the electrode terminals being arranged on the wall portions and electrically connected to the electrode assembly.

[0008] In the above technical solution, the first wall is configured to include a main body and an edge portion connected to the main body, the edge portion is connected to the adjacent wall portion, and the wall thickness of the edge portion is greater than the wall thickness of the main body portion. This structure allows areas of different thicknesses to be formed on the first wall, wherein the main body is the main part of the first wall, and the thickness is relatively small, which can meet the requirements of improving the energy density of the battery. The edge portion is the portion of the first wall connecting the adjacent wall portions, and the thickness is relatively large. Since a certain gap is generally reserved at the edge position of the electrode assembly and the shell, the wall thickness of the edge portion is greater than the wall thickness of the main body. On the one hand, the gap can be fully utilized without occupying the accommodation space required for the electrode assembly. On the other hand, the strength of the connection between the first wall and the adjacent wall portion (i.e., the corner position of the shell) can be improved. When the shell is squeezed, the problem of insufficient strength at the corner position of the shell can be effectively reduced, and the shell's anti-extrusion and impact strength can be improved, thereby improving the reliability of the battery cell and the battery.

[0009] In some embodiments of the present application, the area of ​​the first wall is larger than the areas of the remaining walls.

[0010] In the above technical solution, by setting the area of ​​the first wall to be larger than the area of ​​the remaining walls, that is, the first wall is the large wall of the shell, this method can effectively improve the strength of the large wall, thereby improving the overall strength of the shell. On the other hand, while the large wall can meet the strength requirements, the wall thickness of the main body of the large wall can be made relatively thin, saving materials, and increasing the accommodation space of the electrode assembly in the shell, thereby increasing the volume of the electrode assembly, which is beneficial to improving the battery energy density of the battery cell.

[0011] In some embodiments of the present application, the wall thickness of at least a portion of the edge portion is greater than or equal to the wall thickness of the adjacent wall portion.

[0012] In the above technical solution, by setting the wall thickness of at least part of the edge portion to be greater than or equal to the wall thickness of the adjacent wall portion, the wall thickness of the edge portion is not less than any of the multiple wall portions, that is, the strength of the edge portion is greater than or equal to the strength of the adjacent wall portion. This can reduce the probability of the edge portion becoming a weak area in the shell, and further reduce the probability of insufficient strength at the corner position of the shell. It can be seen that this method has a better effect of enhancing the strength of the edge portion.

[0013] In some embodiments of the present application, the edge portion includes a uniform thickness portion and a gradient portion connecting the uniform thickness portion, the uniform thickness portion is connected to the adjacent wall portion, the gradient portion is connected to the main body portion, and the wall thickness of the gradient portion gradually decreases in the direction in which the gradient portion moves away from the uniform thickness portion.

[0014] In the above technical solution, by configuring the edge portion to include a uniform thickness portion and a gradually transitioning portion connecting the uniform thickness portion, the uniform thickness portion can smoothly transition to the main body portion through the gradually transitioning portion, thereby reducing the likelihood of stress concentration between the main body portion and the edge portion, enhancing the structural stability of the first wall, and improving the reliability of the first wall. Furthermore, the gradually transitioning portion reduces the likelihood of sharp structures such as steps between the edge portion and the main body portion, thereby reducing the likelihood of damage to the electrode assembly during installation into the housing.

[0015] In some embodiments of the present application, in the direction from the main body portion to the gradient portion, the size of the uniform thickness portion is larger than the size of the gradient portion.

[0016] In the above technical solution, the uniform thickness portion in the edge portion mainly plays the role of enhancing strength. By setting the size of the uniform thickness portion to be larger than the size of the gradient portion in the direction from the main body portion to the gradient portion, the uniform thickness portion occupies a larger size in the edge portion, and the effect of strength enhancement is more significant, thereby bringing better strength improvement effect.

[0017] In some embodiments of the present application, in the direction from the main body to the gradient portion, the size of the uniform thickness portion is N, and the size of the gradient portion is M, wherein 2mm≤N≤15mm, and 1mm≤M≤6mm.

[0018] In the above technical solution, by setting the dimension N of the uniform thickness portion in the direction from the main portion toward the transition portion 20122 within the range of 2 mm to 15 mm, the uniform thickness portion can enhance the strength-enhancing effect, resulting in a relatively high strength of the first wall. Furthermore, the impact on the electrode assembly can be reduced, thereby facilitating an increase in battery energy density. Furthermore, by setting the dimension M of the transition portion within the range of 1 mm to 6 mm, the transition portion can enhance the transitional effect between the uniform thickness portion and the main portion. Furthermore, the impact on the electrode assembly can be reduced, thereby facilitating an increase in battery energy density.

[0019] In some embodiments of the present application, the electrode assembly is a lithium iron phosphate electrode assembly or a ternary lithium electrode assembly, wherein, when the electrode assembly is a lithium iron phosphate electrode assembly, 2mm≤N≤10mm, 1mm≤M≤3mm; when the electrode assembly is a ternary lithium electrode assembly, 10mm<N≤15mm, 3mm<M≤6mm.

[0020] In the above technical solution, when the electrode assembly is a lithium iron phosphate electrode assembly, the dimension N of the uniform thickness portion can be one of 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, and 10 mm, and the dimension M of the gradual transition portion can be one of 1 mm, 2 mm, and 3 mm. When the electrode assembly is a ternary lithium electrode assembly, the dimension N of the uniform thickness portion can be one of 11 mm, 12 mm, 13 mm, 14 mm, and 15 mm, and the dimension M of the gradual transition portion can be one of 4 mm, 5 mm, and 6 mm.

[0021] In some embodiments of the present application, a transition fillet is formed between the edge portion and the adjacent wall portion.

[0022] In the above technical solution, by forming a transition radius between the edge portion and the adjacent wall portion, on the one hand, a uniform transition can be achieved between the edge portion and the adjacent wall portion, which is beneficial to reducing the probability of stress concentration and improving the structural stability of the shell, while also enhancing the manufacturability of the shell.

[0023] In some embodiments of the present application, in a direction from the main body portion to the edge portion, the size of the edge portion and the radius of the transition fillet are negatively correlated.

[0024] In the above technical solution, the smaller the radius of the transition fillet, the more pronounced the stress concentration between the first wall and the adjacent wall portion, and the higher the strength requirement for the first wall. Therefore, by making the edge portion larger, the strength of the connection between the first wall and the adjacent wall portion can be improved, reducing the probability of insufficient strength of the first wall. Similarly, the larger the radius of the transition fillet, the greater the effect of reducing stress concentration between the first wall and the adjacent wall portion, and the relatively lower strength requirement for the first wall, so the edge portion can be made smaller.

[0025] In some embodiments of the present application, the radius of the transition fillet is R, where 2 mm ≤ R ≤ 4 mm.

[0026] In the above technical solution, by setting the radius R of the transition fillet within the range of 2mm to 4mm, on the one hand, the radius value of the transition fillet can be set within an appropriate range, which can better reduce the stress concentration between the first wall and the adjacent wall portion; on the other hand, it can reduce the probability of large corners appearing in the outer shell, which is conducive to setting a larger volume of electrode assembly in the outer shell, thereby improving the battery energy density.

[0027] In some embodiments of the present application, the electrode assembly is a lithium iron phosphate electrode assembly or a ternary lithium electrode assembly, wherein, when the electrode assembly is a lithium iron phosphate electrode assembly, 2mm≤R≤3mm; when the electrode assembly is a ternary lithium electrode assembly, 3mm<R≤4mm.

[0028] In the above technical solution, when the electrode assembly is a lithium iron phosphate electrode assembly, the radius R of the transition fillet can be one of 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, and 3.0mm; when the electrode assembly is a ternary lithium electrode assembly, the radius R of the transition fillet can be one of 3.2mm, 3.4mm, 3.6mm, 3.8mm, and 4.0mm.

[0029] In some embodiments of the present application, multiple wall portions include a second wall, second walls are provided at both ends of the first direction of the first wall, electrode terminals are provided on at least one of the remaining wall portions except the second wall and the first wall, and an edge portion is provided at the end of the main body close to the second wall, and the edge portion is connected to the second wall.

[0030] In the above technical solution, in the first wall, both ends of the main body in the first direction are provided with edge portions, and the two ends of the main body in the first direction are connected to the second wall through the edge portions. This can improve the strength of the two ends of the main body. When the first wall is squeezed, the strength of the position where the first wall and the second wall meet is improved, which can further improve the overall strength of the first wall.

[0031] In some embodiments of the present application, the multiple wall portions include a third wall, the third wall is provided at one end of the first wall in the second direction, the third wall and the second wall are arranged adjacent to each other, and the end of the main body close to the third wall is also provided with an edge portion, and the edge portion is connected to the third wall.

[0032] In the above technical solution, in the first wall, the two ends of the main body can be connected to the second wall through the edge portion, and one of the other two opposite ends can also be connected to the third wall through the edge portion. In this way, except for the end adjacent to the end cover in the first wall, the ends of the remaining parts can be connected to the adjacent wall portions through the edge portion, so that the strength of multiple ends of the first wall is enhanced, and the strength of the first wall can be further improved.

[0033] In some embodiments of the present application, the thickness of the third wall is greater than the thickness of the second wall, and the electrode terminal is provided on the third wall.

[0034] In the above technical solution, by setting the wall thickness of the third wall to be greater than the wall thickness of the second wall, the strength of the third wall is relatively high, so arranging the electrode terminal on the third wall can improve the installation reliability of the electrode terminal.

[0035] In a second aspect, an embodiment of the present application further provides a battery, comprising the battery cell as described above.

[0036] In the above technical solution, since in the outer shell of the battery cell, the first wall includes a main body and an edge portion connected to the main body, the edge portion is connected to the adjacent wall portion, and the wall thickness of the edge portion is greater than the wall thickness of the main body, this method can improve the strength of the first wall, and then improve the anti-extrusion and impact strength of the outer shell, thereby improving the reliability of the battery.

[0037] In a third aspect, an embodiment of the present application further provides an electrical device, comprising a battery cell as described above, or a battery as described above.

[0038] In the above technical solution, since the battery cells or batteries have relatively high anti-extrusion and anti-impact strength, the battery cells or batteries are relatively reliable, which is beneficial to improving the use stability of the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0040] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0041] FIG2 is an exploded view of the structure of a battery provided in some embodiments of the present application;

[0042] FIG3 is a first structural diagram of a housing provided in some embodiments of the present application;

[0043] FIG4 is a second structural diagram of a housing provided in some embodiments of the present application;

[0044] FIG5 is a third structural diagram of a housing provided in some embodiments of the present application;

[0045] FIG6 is a schematic diagram of FIG5 taken along line AA;

[0046] FIG7 is a partial enlarged schematic diagram of point I in FIG6;

[0047] FIG8 is a schematic diagram of FIG5 taken along line BB;

[0048] FIG9 is a partial enlarged schematic diagram of point II in FIG8 .

[0049] Icons: 1000, vehicle; 100, battery; 10, box body; 11, first box body; 12, second box body; 20, battery cell; 21, outer shell; 211, wall; 201, first wall; 2011, main body; 2012, edge; 20121, uniform thickness portion; 20122, gradient portion; 202, second wall; 203, third wall; 203a, via; 212, transition fillet; 22, pressure relief portion; 2001, shell; 2001a, opening; 200, controller; 300, motor; X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0050] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0051] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0052] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0053] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0054] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0055] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0056] The term "plurality" used in this application refers to two or more (including two).

[0057] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0058] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or battery pack. A battery generally includes a casing that encloses one or more battery cells or multiple battery modules. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0059] A battery cell includes a casing, an electrode assembly, and an electrolyte. The casing is used to hold the electrode assembly and the electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet consists of a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector. The negative current collector uncoated with the negative active material layer protrudes from the negative current collector coated with the negative active material layer. The negative current collector uncoated with the negative active material layer serves as the negative electrode tab. The negative current collector can be made of copper, and the negative active material can be carbon, silicon, or other materials. To ensure that high currents can pass without melting, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are stacked together.

[0060] The material of the isolation film may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly may be a wound structure or a laminated structure, but the embodiments of the present application are not limited thereto.

[0061] New energy vehicles have experienced rapid growth in recent years. Within the electric vehicle sector, power batteries, as the power source, play an irreplaceable and important role. A battery consists of a housing and multiple cells housed within it. As a core component in new energy vehicles, batteries have high requirements for both safety and cycle life.

[0062] In typical power batteries, to ensure sufficient power, multiple battery cells are typically stacked within a battery housing, with end plates positioned at the ends of the cells. However, since the battery cells include a housing, and to increase battery energy density, the housing is often designed with a thin shell structure, the housing can be subject to insufficient strength when squeezed by one or more of the end plates, the battery housing, or adjacent battery cells. This is particularly true at the corners of the housing, increasing the likelihood of housing damage and significantly reducing the reliability of the battery cells, which in turn affects battery reliability, significantly reducing battery performance, and shortening the battery's service life.

[0063] Based on the above considerations, in order to solve the problem of insufficient strength of the battery cell shell, the inventor designed a battery cell, including: a shell, an electrode assembly and an electrode terminal, the shell having multiple wall portions, the multiple wall portions including a first wall, the first wall including a main body portion and an edge portion connected to the main body portion, the edge portion being connected to the adjacent wall portion, the wall thickness of the edge portion being greater than the wall thickness of the main body portion, the electrode assembly being arranged in the shell, the electrode terminal being arranged on the wall portion, and electrically connected to the electrode assembly.

[0064] In a battery cell of this structure, the first wall is configured to include a main body and an edge portion connected to the main body, the edge portion is connected to the adjacent wall portion, and the wall thickness of the edge portion is greater than the wall thickness of the main body portion. This structure allows areas of different thicknesses to be formed on the first wall, wherein the main body is the main portion of the first wall and has a relatively small thickness, which can meet the requirements of improving the energy density of the battery. The edge portion is the portion of the first wall connecting the adjacent wall portions and has a relatively large thickness. Since a certain gap is generally reserved at the edge position of the electrode assembly and the shell, the wall thickness of the edge portion is greater than the wall thickness of the main body. On the one hand, the gap can be fully utilized without occupying the accommodation space required for the electrode assembly. On the other hand, the strength of the connection between the first wall and the adjacent wall portion (i.e., the corner position of the shell) can be improved. When the shell is squeezed, the problem of insufficient strength at the corner position of the shell can be effectively reduced, and the shell's anti-extrusion and impact strength can be improved, thereby improving the reliability of the battery cell and the battery.

[0065] The battery disclosed in the embodiments of this application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery cells and batteries disclosed in this application can be used to form the electrical device, thereby increasing the scope of application of the battery cells.

[0066] The embodiments of the present application provide an electrical device that uses a battery or battery cell as a power source. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0067] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0068] Please refer to Figure 1, which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0069] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0070] Please refer to Figure 2, which is an exploded view of the structure of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 10 and a plurality of battery cells 20, which are intended to be accommodated within the housing 10. The housing 10 is used to provide an assembly space for the battery cells 20, and the housing 10 can adopt a variety of structures. In some embodiments, the housing 10 can include a first housing body 11 and a second housing body 12, which cover each other and together define an assembly space for accommodating the battery cells 20. The second housing body 12 can be a hollow structure with one end open, and the first housing body 11 can be a plate-like structure, with the first housing body 11 covering the open side of the second housing body 12, so that the first housing body 11 and the second housing body 12 jointly define an assembly space. The first housing body 11 and the second housing body 12 can also be hollow structures with one end open, with the open side of the first housing body 11 covering the open side of the second housing body 12. Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cuboid, etc.

[0071] In the battery 100, the multiple battery cells 20 can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery 100 can be constructed by first connecting the multiple battery cells 20 in series, in parallel, or in a hybrid configuration to form a battery module, which is then connected in series, in parallel, or in a hybrid configuration to form a single structure and housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0072] In some embodiments, the battery 100 includes multiple rows of battery cells 20, and the multiple rows of battery cells 20 can be arranged along the length direction of the box 10, and each row of battery cells 20 includes multiple battery cells 20 arranged along the width direction of the box 10; or, the multiple rows of battery cells 20 can be arranged along the width direction of the box 10, and each row of battery cells 20 includes multiple battery cells 20 arranged along the length direction of the box 10.

[0073] Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 can be cylindrical, flat, rectangular, or in other shapes. For example, the battery cell 20 is cylindrical.

[0074] According to some embodiments of the present application, referring to Figure 3, Figure 3 shows a battery cell 20 provided by some embodiments of the present application, including: a shell 21, an electrode assembly (not shown in the figure), and an electrode terminal (not shown in the figure). The shell 21 has multiple wall portions 211, and the multiple wall portions 211 include a first wall 201. The first wall 201 includes a main body 2011 and an edge portion 2012 connected to the main body 2011. The edge portion 2012 is connected to the adjacent wall portion 211, and the wall thickness of the edge portion 2012 is greater than the wall thickness of the main body 2011; the electrode assembly is arranged in the shell 21; the electrode terminal is arranged on the wall portion 211 and is electrically connected to the electrode assembly.

[0075] The outer shell 21 is a thin shell structure for accommodating electrode assemblies and electrolytes. The outer shell 21 may include but is not limited to an aluminum shell and a steel shell. The outer shell 21 has a plurality of wall portions 211, and the plurality of wall portions 211 are connected to define a storage space for accommodating electrode assemblies and electrolytes. The first wall 201 may refer to the wall portion 211 whose strength needs to be improved, the main body 2011 may refer to the main body of the first wall 201, and the edge portion 2012 may refer to the edge portion of the first wall 201. Exemplarily, the edge portion 2012 may be provided at at least one end of the main body 2011. Since the wall thickness of the edge portion 2012 is greater than the wall thickness of the main body 2011 and is connected to the adjacent wall portions 211, the edge portion 2012 can play a role in improving the strength of the connection position between the first wall 201 and the adjacent wall portions 211.

[0076] An electrode terminal can refer to a component that connects an electrode assembly to an external conductor. For example, an electrode terminal can refer to a pole. There are at least two electrode terminals, including a positive terminal and a negative terminal, to connect to the positive and negative electrodes of an external power supply.

[0077] In the above technical solution, the first wall 201 is configured to include a main body 2011 and an edge portion 2012 connected to the main body 2011, the edge portion 2012 is connected to the adjacent wall portion 211, and the wall thickness of the edge portion 2012 is greater than the wall thickness of the main body 2011. This structure allows areas of different thicknesses to be formed on the first wall 201, wherein the main body 2011 is the main part of the first wall 201 and has a relatively small thickness, which can meet the requirements of improving the battery energy density, and the edge portion 2012 is the portion of the first wall 201 connecting the adjacent wall portion 211 and has a relatively large thickness. Since a certain gap is generally reserved at the edge of the electrode assembly and the shell 21, the wall thickness of the edge portion 2012 is greater than the wall thickness of the main body 2011. On the one hand, the gap can be fully utilized without occupying the accommodation space required for the electrode assembly. On the other hand, the strength of the connection between the first wall 201 and the adjacent wall portion 211 (i.e., the corner position of the shell 21) can be improved. When the shell 21 is squeezed, the problem of insufficient strength at the corner position of the shell 21 can be effectively reduced, and the anti-extrusion and impact strength of the shell 21 can be improved, thereby improving the reliability of the battery cell 20 and the battery 100.

[0078] In some embodiments of the present application, as shown in Figures 3 and 5 , the area of ​​the first wall 201 is larger than the area of ​​the remaining walls 211. It can be understood that the first wall 201 is the large wall of the housing 21, and its strength is lower than that of the other walls 211. In other words, it can refer to the relatively weak wall 211 of the housing 21. For example, if the housing 21 is a square aluminum shell, the first wall 201 can refer to the two larger side walls.

[0079] In the above technical solution, by setting the area of ​​the first wall 201 to be larger than the area of ​​the remaining wall portions 211, that is, the first wall 201 is the large wall of the outer shell 21, this method can effectively improve the strength of the large wall, thereby improving the overall strength of the outer shell 21. On the other hand, while the large wall can meet the strength requirements, the wall thickness of the main body 2011 of the large wall can be made relatively thin, saving materials, and increasing the accommodation space of the electrode assembly in the outer shell 21, thereby increasing the volume of the electrode assembly, which is beneficial to improving the battery energy density of the battery cell 20.

[0080] In some embodiments of the present application, the wall thickness of at least a portion of the edge portion 2012 is greater than or equal to the wall thickness of the adjacent wall portion 211 .

[0081] It can be understood that the wall thickness of at least part of the edge portion 2012 can be equal to the wall thickness of the adjacent wall portion 211 (refer to Figure 7, the wall thickness of the adjacent wall portion 211 is T1, and the wall thickness of at least part of the edge portion 2012 is T3, T1 and T3 are equal). In this way, the transition between the edge portion 2012 and the adjacent wall portion 211 can be more uniform, thereby improving the manufacturability of the shell 21. Moreover, the wall thickness of the edge portion 2012 is equal to the wall thickness of the adjacent wall portion 211, which can also make the strength of the edge portion 2012 and the adjacent wall portion 211 relatively high, thereby improving the overall strength of the shell 21.

[0082] The wall thickness of at least part of the edge portion 2012 can also be greater than the wall thickness of the adjacent wall portion 211. In this way, the strength of the edge portion 2012 is greater than the strength of the main body portion 2011 and the adjacent wall portion 211. In this way, the edge portion 2012 has relatively high strength, and when the shell 21 is squeezed, the corner position has better anti-extrusion and impact resistance.

[0083] In the above technical solution, by setting the wall thickness of at least part of the edge portion 2012 to be greater than or equal to the wall thickness of the adjacent wall portion 211, the wall thickness of the edge portion 2012 is not less than any of the multiple wall portions 211, that is, the strength of the edge portion 2012 is greater than or equal to the strength of the adjacent wall portion 211. This can reduce the probability of the edge portion 2012 becoming a weak area in the outer shell 21, and further reduce the probability of insufficient strength at the corner position of the outer shell 21. It can be seen that this method can achieve a better effect of enhancing the strength of the edge portion 2012.

[0084] In some embodiments of the present application, as shown in Figures 7 and 9, the edge portion 2012 includes a uniform thickness portion 20121 and a gradient portion 20122 connected to the uniform thickness portion 20121, the uniform thickness portion 20121 is connected to the adjacent wall portion 211, and the gradient portion 20122 is connected to the main body portion 2011. In the direction in which the gradient portion 20122 moves away from the uniform thickness portion 20121, the wall thickness of the gradient portion 20122 gradually decreases.

[0085] The uniform thickness portion 20121 may refer to a portion of the edge portion 2012 having uniform thickness.

[0086] The gradient portion 20122 may refer to a portion of the edge portion 2012 where the thickness gradually changes.

[0087] 3 to 7 , the housing 21 may have a first direction X, a second direction Y, and a third direction Z, wherein the first direction X, the second direction Y, and the third direction Z are mutually perpendicular, and the first direction X, the second direction Y, and the third direction Z may be one of the length, width, and height directions of the housing 21. The ends of the first wall 201 in the first direction X and the third direction Z are connected to the wall portion 211. Referring to 6 and FIG7 , in the first wall 201, the end of the main body portion 2011 in the third direction Z is connected to the wall portion 211 via the edge portion 2012, and the gradient portion 20122 may be arranged along the third direction Z in a direction away from the uniform thickness portion 20121. The wall thickness of the gradient portion 20122 may refer to the dimension along the first direction X. Referring to Figures 8 and 9, in the first wall 201, the end of the main body 2011 in the first direction X is connected to the wall portion 211 through the edge portion 2012, and the gradient portion 20122 can be set along the first direction X away from the uniform thickness portion 20121, and the wall thickness of the gradient portion 20122 can refer to the dimension along the second direction Y.

[0088] The surface of the gradient portion 20122 located on the inner side of the housing 21 may include but is not limited to an inclined surface and an arc surface.

[0089] In the above technical solution, by configuring the edge portion 2012 to include a uniform thickness portion 20121 and a gradual transition portion 20122 connecting the uniform thickness portion 20121, the uniform thickness portion 20121 can be smoothly transitioned to the main body 2011 via the gradual transition portion 20122, thereby reducing the probability of stress concentration between the main body 2011 and the edge portion 2012, enhancing the structural stability of the first wall 201, and improving the reliability of the first wall 201. Furthermore, the gradual transition portion 20122 can also reduce the probability of sharp structures such as steps forming between the edge portion 2012 and the main body 2011, thereby reducing the probability of damage to the electrode assembly during installation into the housing 21.

[0090] In some embodiments of the present application, as shown in FIG. 7 and FIG. 9 , in the direction from the main body 2011 to the gradient portion 20122 , the dimension N of the uniform thickness portion 20121 is greater than the dimension M of the gradient portion 20122 .

[0091] 6 and 7 , in the first wall 201 , an end portion of the main portion 2011 in the third direction Z is connected to the wall portion 211 via the edge portion 2012 , and the direction from the main portion 2011 to the transition portion 20122 may be along the third direction Z. Referring to FIG. 8 and FIG. 9 , in the first wall 201 , an end portion of the main portion 2011 in the first direction X is connected to the wall portion 211 via the edge portion 2012 , and the direction from the main portion 2011 to the transition portion 20122 may be along the first direction X.

[0092] In the above technical solution, the uniform thickness portion 20121 in the edge portion 2012 mainly plays the role of enhancing strength. By setting the size N of the uniform thickness portion 20121 to be larger than the size M of the gradient portion 20122 in the direction from the main body portion 2011 to the gradient portion 20122, the uniform thickness portion 20121 occupies a larger size in the edge portion 2012, and the effect of strength enhancement is more significant, thereby bringing about a better strength improvement effect.

[0093] In some embodiments of the present application, as shown in Figures 7 and 9, in the direction from the main body 2011 to the gradient portion 20122, the size of the uniform thickness portion 20121 is N, and the size of the gradient portion 20122 is M, wherein 2mm≤N≤15mm, 1mm≤M≤6mm.

[0094] The size N of the uniform thickness portion 20121 may include, but is not limited to, any one of 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, and 15 mm. In this embodiment, if the size N of the uniform thickness portion 20121 is less than 2 mm, the strength enhancement effect achieved is relatively poor, which is not conducive to significantly improving the strength of the first wall 201. If the size N of the uniform thickness portion 20121 is greater than 15 mm, although it can provide a good strength enhancement effect, the size N of the uniform thickness portion 20121 is relatively large, which has a greater impact on the electrode assembly, making it difficult to install a larger electrode assembly, thereby affecting the battery energy density.

[0095] The dimension M of the transition portion 20122 may include, but is not limited to, any one of 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, and 6 mm. In this embodiment, if the dimension M of the transition portion 20122 is less than 1 mm, the transition effect is relatively poor, and the effect of reducing stress concentration is relatively poor. If the dimension M of the transition portion 20122 is greater than 6 mm, although it can provide a better transition effect, the dimension M of the transition portion 20122 is relatively large, which increases the impact on the electrode assembly, making it difficult to install a larger electrode assembly, thereby affecting the battery energy density.

[0096] In the above technical solution, by setting the dimension N of the uniform thickness portion 20121 in the direction from the main portion 2011 to the gradient portion 20122 within the range of 2 mm to 15 mm, the uniform thickness portion 20121 can enhance the strength-enhancing effect, thereby providing a relatively high strength to the first wall 201. Furthermore, the impact on the electrode assembly can be reduced, thereby facilitating an increase in battery energy density. Furthermore, by setting the dimension M of the gradient portion 20122 within the range of 1 mm to 6 mm, the gradient portion 20122 can enhance the transitional effect between the uniform thickness portion 20121 and the main portion 2011. Furthermore, the impact on the electrode assembly can be reduced, thereby facilitating an increase in battery energy density.

[0097] In some embodiments of the present application, the electrode assembly is a lithium iron phosphate electrode assembly or a ternary lithium electrode assembly, wherein, when the electrode assembly is a lithium iron phosphate electrode assembly, 2mm≤N≤10mm, 1mm≤M≤3mm; when the electrode assembly is a ternary lithium electrode assembly, 10mm<N≤15mm, 3mm<M≤6mm.

[0098] In the above technical solution, when the electrode assembly is a lithium iron phosphate electrode assembly, the dimension N of the uniform thickness portion 20121 can be one of 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm, and the dimension M of the gradually transitioning portion 20122 can be one of 1 mm, 2 mm, or 3 mm. When the electrode assembly is a ternary lithium electrode assembly, the dimension N of the uniform thickness portion 20121 can be one of 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm, and the dimension M of the gradually transitioning portion 20122 can be one of 4 mm, 5 mm, or 6 mm.

[0099] In some embodiments of the present application, as shown in FIG. 7 and FIG. 9 , a transition fillet 212 is formed between the edge portion 2012 and the adjacent wall portion 211 .

[0100] In the above technical solution, by forming a transition radius 212 between the edge portion 2012 and the adjacent wall portion 211, on the one hand, a uniform transition can be achieved between the edge portion 2012 and the adjacent wall portion 211, which is beneficial to reducing the probability of stress concentration and improving the structural stability of the shell 21, while also enhancing the manufacturability of the shell 21.

[0101] In some embodiments of the present application, in the direction from the main body 2011 to the edge portion 2012, the size of the edge portion 2012 and the radius of the transition fillet 212 are negatively correlated. In other words, the larger the radius of the transition fillet 212, the smaller the size of the edge portion 2012; and the smaller the radius of the transition fillet 212, the larger the size of the edge portion 2012.

[0102] In the above technical solution, the smaller the radius of the transition fillet 212, the more pronounced the stress concentration between the first wall 201 and the adjacent wall portion 211, and the higher the strength requirement for the first wall 201. Therefore, by making the edge portion 2012 larger, the strength of the connection between the first wall 201 and the adjacent wall portion 211 can be improved, reducing the probability of insufficient strength of the first wall 201. Similarly, the larger the radius of the transition fillet 212, the greater the effect of reducing stress concentration between the first wall 201 and the adjacent wall portion 211, and the relatively lower strength requirement for the first wall 201. Therefore, the edge portion 2012 can be made smaller.

[0103] In some embodiments of the present application, the radius of the transition fillet 212 is R, where 2 mm ≤ R ≤ 4 mm.

[0104] The radius R of the transition fillet 212 may include, but is not limited to, one of 2 mm, 3 mm, and 4 mm. If the radius R of the transition fillet 212 is less than 2 mm, the effect of reducing the probability of stress concentration is relatively poor. If the radius R of the transition fillet 212 is greater than 4 mm, the space at the corner position within the housing 21 increases. Since the electrode assembly must avoid the corner position of the housing 21, it is not conducive to the installation of a larger electrode assembly.

[0105] In the above technical solution, by setting the radius R of the transition fillet 212 within the range of 2mm to 4mm, on the one hand, the radius value of the transition fillet 212 can be set within an appropriate range, which can better reduce the stress concentration between the first wall 201 and the adjacent wall portion 211. On the other hand, it can reduce the probability of large corners appearing in the outer shell 21, which is conducive to setting a larger volume of electrode assembly in the outer shell 21, thereby improving the battery energy density.

[0106] In some embodiments of the present application, the electrode assembly is a lithium iron phosphate electrode assembly or a ternary lithium electrode assembly, wherein, when the electrode assembly is a lithium iron phosphate electrode assembly, 2mm≤R≤3mm; when the electrode assembly is a ternary lithium electrode assembly, 3mm<R≤4mm.

[0107] In the above technical solution, when the electrode assembly is a lithium iron phosphate electrode assembly, the radius R of the transition fillet 212 can be one of 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, and 3.0mm; when the electrode assembly is a ternary lithium electrode assembly, the radius R of the transition fillet 212 can be one of 3.2mm, 3.4mm, 3.6mm, 3.8mm, and 4.0mm.

[0108] In some embodiments of the present application, as shown in Figures 3, 4, 8 and 9, multiple wall portions 211 include a second wall 202, and second walls 202 are provided at both ends of the first wall 201 in the first direction X. Electrode terminals are provided on at least one of the remaining wall portions 211 except the second wall 202 and the first wall 201, and an edge portion 2012 is provided at the end of the main body 2011 close to the second wall 202, and the edge portion 2012 is connected to the second wall 202.

[0109] It can be understood that the two ends of the main body 2011 are connected to the second wall 202 via the edge portion 2012. For example, there may be two first walls 201 that are disposed opposite each other, with the second wall 202 disposed at the opposite ends of each first wall 201. For example, taking the outer shell 21 as a square shell, the first walls 201 may be the two large side walls of the outer shell 21, and the second walls 202 may be the two small side walls of the outer shell 21. Except for the second wall 202 and the first wall 201, the remaining wall portions 211 may be the top wall and the bottom wall. That is, at least one electrode terminal may be disposed on the top wall or the bottom wall of the outer shell 21.

[0110] In the above technical solution, in the first wall 201, both ends of the main body 2011 in the first direction X are provided with edge portions 2012, and the two ends of the main body 2011 in the first direction X are connected to the second wall 202 through the edge portions 2012. This can improve the strength of the two ends of the main body 2011. When the first wall 201 is squeezed, the strength of the joint position between the first wall 201 and the second wall 202 is improved, which can further improve the overall strength of the first wall 201.

[0111] In some embodiments of the present application, as shown in Figures 3, 4, 6 and 7, multiple wall portions 211 include a third wall 203, a third wall 203 is provided at one end of the first wall 201 in the second direction Y, the third wall 203 and the second wall 202 are arranged adjacent to each other, and an edge portion 2012 is also provided at the end of the main body 2011 close to the third wall 203, and the edge portion 2012 is connected to the third wall 203.

[0112] 3 and 6 , the outer shell 21 may include a shell body 2001 and an end cover (not shown in the figure), the end cover 2001 is covered on the opening 2001a of the shell body, one of the multiple wall portions 211 is formed on the end cover, and the rest are formed on the shell body 2001, the first wall 201 may be two opposite shell walls in the shell body 2001, the second wall 202 may be another two opposite shell walls in the shell body 2001, and the third wall 203 may be a top wall or a bottom wall, that is, the main body 2011 of the first wall 201 can also be connected to the third wall 203 through the edge portion 2012.

[0113] In the above technical solution, in the first wall 201, the two ends of the main body 2011 can be connected to the second wall 202 through the edge portion 2012, and one of the other two opposite ends can also be connected to the third wall 203 through the edge portion 2012. In this way, except for the end adjacent to the end cover in the first wall 201, the ends of the remaining parts can be connected to the adjacent wall portion 211 through the edge portion 2012, so that the strength of multiple ends of the first wall 201 is enhanced, and the strength of the first wall 201 can be further improved.

[0114] In some embodiments of the present application, as shown in FIG. 7 and FIG. 9 , the thickness of the third wall 203 is greater than the thickness of the second wall 202 , and the electrode terminal is provided on the third wall 203 .

[0115] As previously mentioned, the third wall 203 may refer to the wall portion 211 opposite the opening 2001a of the housing 2001. For example, the third wall 203 may be the bottom wall. The third wall 203 may refer to the wall portion 211 that mates with the opening 2001a of the housing 2001. For example, the third wall 203 may be the top wall. Referring to Figures 7 and 9 , the thickness of the third wall 203 may be T1, and the thickness of the second wall 202 may be T4, where T1 is greater than T4.

[0116] Optionally, the third wall 203 may be provided with a via hole 203a through which the electrode terminal passes. The number of the via holes 203a is equal to and corresponds to the number of the electrode terminals. For example, if there are two electrode terminals, there are two via holes 203a.

[0117] Optionally, a pressure relief portion 22 may be provided on the third wall 203 , and the pressure relief portion 22 is an explosion-proof valve.

[0118] In the above technical solution, by setting the wall thickness of the third wall 203 to be greater than the wall thickness of the second wall 202, the strength of the third wall 203 is relatively high, so arranging the electrode terminal on the third wall 203 can improve the installation reliability of the electrode terminal.

[0119] According to an embodiment of the present application, the outer shell 21 of the battery cell 20 is an aluminum shell, and the first wall 201 of the aluminum shell is a large wall. The wall thickness at the corner where the large wall and the adjacent small wall meet is uniformly thinned from 0.5 mm to 0.3 mm, and the wall thickness at the corner where the large wall and the adjacent small wall meet is equal (refer to the thickness T4 in FIG9 ), thereby improving the shell strength when squeezed by the module end plate.

[0120] According to another embodiment of the present application, the outer shell 21 of the battery cell 20 is an aluminum shell, and the first wall 201 of the aluminum shell is a large wall. The wall thickness at the corner where the large wall meets the adjacent top wall is uniformly thinned from 1.5 mm to 0.3 mm (refer to Figure 7, the wall thickness T3 is 1.5 mm, and the wall thickness T2 is 0.3 mm). The wall thickness at the corner where the large wall meets the adjacent top wall is equal (refer to the thickness T1 in Figure 7), thereby improving the impact strength when squeezed by the module end plate.

[0121] In a second aspect, an embodiment of the present application further provides a battery 100 , comprising the battery cell 20 as described above.

[0122] In the above technical solution, since in the outer shell 21 of the battery cell 20, the first wall 201 includes a main body 2011 and an edge portion 2012 connected to the main body 2011, the edge portion 2012 is connected to the adjacent wall portion 211, and the wall thickness of the edge portion 2012 is greater than the wall thickness of the main body 2011, this method can improve the strength of the first wall 201, and then improve the anti-extrusion and impact strength of the outer shell 21, thereby improving the reliability of the battery 100.

[0123] In a third aspect, an embodiment of the present application further provides an electrical device, comprising the battery cell 20 as described above, or the battery 100 as described above.

[0124] In the above technical solution, since the battery cell 20 or the battery 100 has relatively high anti-extrusion and anti-impact strength, the battery cell 20 or the battery 100 is relatively reliable, which is beneficial to improving the use stability of the electrical device.

[0125] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0126] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, wherein: include: A shell, wherein the shell has a plurality of wall portions, wherein the plurality of wall portions include a first wall, wherein the first wall includes a main body portion and an edge portion connected to the main body portion, wherein the edge portion is connected to an adjacent wall portion, and a wall thickness of the edge portion is greater than a wall thickness of the main body portion; an electrode assembly, the electrode assembly being disposed in the housing; The electrode terminal is disposed on the wall portion and is electrically connected to the electrode assembly.

2. The battery cell according to claim 1, wherein: The area of ​​the first wall is larger than the areas of the remaining wall portions.

3. The battery cell according to claim 1 or 2, wherein: The wall thickness of at least a portion of the edge portion is greater than or equal to the wall thickness of the adjacent wall portion.

4. The battery cell according to any one of claims 1 to 3, wherein: The edge portion includes a uniform thickness portion and a gradual change portion connected to the uniform thickness portion, the uniform thickness portion is connected to the adjacent wall portion, the gradual change portion is connected to the main body portion, and the wall thickness of the gradual change portion gradually decreases in the direction in which the gradual change portion moves away from the uniform thickness portion.

5. The battery cell according to claim 4, wherein: In a direction from the main body portion to the gradient portion, a size of the uniform thickness portion is larger than a size of the gradient portion.

6. The battery cell according to claim 5, wherein: In the direction from the main body to the gradient portion, the size of the uniform thickness portion is N, and the size of the gradient portion is M, wherein 2mm≤N≤15mm, and 1mm≤M≤6mm.

7. The battery cell according to claim 6, wherein: The electrode assembly is a lithium iron phosphate electrode assembly or a ternary lithium electrode assembly, wherein: When the electrode assembly is the lithium iron phosphate electrode assembly, 2mm≤N≤10mm, 1mm≤M≤3mm; When the electrode assembly is the ternary lithium electrode assembly, 10mm<N≤15mm, 3mm<M≤6mm.

8. The battery cell according to any one of claims 1 to 7, wherein: A transition fillet is formed between the edge portion and the adjacent wall portion.

9. The battery cell according to claim 8, wherein: In a direction from the main body portion to the edge portion, a size of the edge portion and a radius of the transition fillet are negatively correlated.

10. The battery cell according to claim 8 or 9, wherein: The radius of the transition fillet is R, wherein 2mm≤R≤4mm.

11. The battery cell according to claim 10, wherein: The electrode assembly is a lithium iron phosphate electrode assembly or a ternary lithium electrode assembly, wherein: When the electrode assembly is the lithium iron phosphate electrode assembly, 2mm≤R≤3mm; When the electrode assembly is the ternary lithium electrode assembly, 3mm<R≤4mm.

12. The battery cell according to any one of claims 1 to 11, wherein: The multiple wall portions include a second wall, the second walls are provided at both ends of the first direction of the first wall, the electrode terminal is provided on at least one of the remaining wall portions except the second wall and the first wall, and the edge portion is provided at the end of the main body close to the second wall, and the edge portion is connected to the second wall.

13. The battery cell according to claim 12, wherein: The multiple wall portions include a third wall, the third wall is provided at one end of the first wall in the second direction, the third wall and the second wall are arranged adjacent to each other, and the end of the main body close to the third wall is also provided with the edge portion, and the edge portion is connected to the third wall.

14. The battery cell according to claim 13, wherein: The thickness of the third wall is greater than that of the second wall, and the electrode terminal is disposed on the third wall.

15. A battery, wherein: The invention comprises the battery cell according to any one of claims 1 to 14.

16. An electrical device, wherein: Comprising the battery cell according to any one of claims 1 to 14, or the battery according to claim 15.

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