Battery monomer, battery, energy storage device and power utilization device

Abstract

The utility model discloses a battery monomer, a battery, an energy storage device and a power utilization device. The battery cell includes a housing. An opening is formed in the end portion of the shell in the first direction. The shell comprises a first wall, a corner area and a second wall which are sequentially connected in the circumferential direction of the opening. The first wall is provided with a first body part and a first thickening part which are arranged in the first direction, the first body part is far away from the opening compared with the first thickening part, and the maximum thickness of the first thickening part is larger than that of the first body part. Wherein the corner area is provided with a second body part and a second thickening part which are arranged in the first direction, the second body part is farther from the opening than the second thickening part, and the maximum thickness of the second thickening part is larger than the thickness of the second body part. According to the technical scheme provided by the invention, the reliability of the battery monomer can be improved.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to PCT patent application PCT / CN2023 / 134129 entitled “Casing, battery cell, battery and electrical device” filed on November 24, 2023, the entire contents of which are incorporated herein by reference. Technical Field

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

[0004] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0005] In the development of battery technology, how to improve battery reliability is a technical problem that needs to be solved urgently. Utility Model Content

[0006] The present application provides a battery cell, a battery, an energy storage device and an electrical device. The technical solution provided in the present application can improve the reliability of the battery cell.

[0007] This application is achieved through the following technical solutions:

[0008] In a first aspect, some embodiments of the present application provide a battery cell. The battery cell includes a shell. An opening is formed at an end of the shell along a first direction. Along the circumference of the opening, the shell includes a first wall, a corner area, and a second wall connected in sequence. The first wall has a first main body portion and a first thickened portion arranged along the first direction, the first main body portion is farther away from the opening than the first thickened portion, and the maximum thickness of the first thickened portion is greater than the thickness of the first main body portion. Among them, the corner area has a second main body portion and a second thickened portion arranged along the first direction, the second main body portion is farther away from the opening than the second thickened portion, and the maximum thickness of the second thickened portion is greater than the thickness of the second main body portion.

[0009] In the above scheme, by providing the first thickened portion on the first wall, the problem that the heat-affected zone with low strength is formed by welding of the shell, which causes the first wall to crack due to insufficient strength when impacted, can be improved, so that the battery has higher reliability. At the same time, by providing the second thickened portion in the corner area, the strength of the corner area corresponding to the opening can be improved, and the problem that the stress concentration during the shell manufacturing process caused by the provision of the first thickened portion (for example, when the shell is stretched and formed, the stress generated during demoulding will be concentrated on the corner area corresponding to the opening) causing the corner area to crack can be improved, so that the battery cell has higher reliability.

[0010] According to some embodiments of the present application, the maximum thickness of the second thickened portion is greater than the maximum thickness of the first thickened portion.

[0011] In the above scheme, by setting the maximum thickness of the second thickened portion to be greater than the maximum thickness of the first thickened portion, the strength of the portion of the corner area corresponding to the opening can be effectively improved. On the one hand, the overall thickness of the shell can be effectively increased to reduce the risk of cracking of the shell due to impact. On the other hand, the stress concentration during the shell manufacturing process can be effectively improved, which causes the problem of cracking in the corner area, thereby making the battery cell have higher reliability.

[0012] According to some embodiments of the present application, the maximum thickness of the second thickened portion is T1, the thickness of the second main body portion is T2, the maximum thickness of the first thickened portion is t1, and the thickness of the first main body portion is t2, satisfying E≥F, E=(T1-T2) / T2, and F=(t1-t2) / t2.

[0013] In the above scheme, by limiting the degree of thickening E of the second thickened portion compared to the second main body portion to be no less than the degree of thickening F of the first thickened portion compared to the first main body portion, the problem of stress concentration in the shell manufacturing process caused by the provision of the first thickened portion, resulting in cracks in the corner area, can be effectively improved, so that the battery cell has higher reliability.

[0014] According to some embodiments of the present application, the maximum thickness of the second thickened portion is T1, and the thickness of the second main body portion is T2, satisfying 0<E<30%, and E=(T1-T2) / T2.

[0015] In the above scheme, by limiting the degree E of thickening of the second thickened portion compared to the second main body portion, on the one hand, the strength of the corner area can be improved and the risk of cracking in the corner area due to stress concentration can be reduced; on the other hand, the risk of bulging of the corner area and deformation of the outer shell due to excessive stress can be reduced, so that the battery cell has higher reliability.

[0016] According to some embodiments of the present application, 0<E≤16.7% is satisfied.

[0017] In the above scheme, by limiting the degree of thickening E of the second thickened portion relative to the second main body portion to no more than 16.7%, on the one hand, it can take into account the improvement of the problems of cracking caused by stress concentration and deformation caused by excessive stress; on the other hand, it can effectively control the weight of the shell, which is beneficial to the improvement of the weight energy density of the battery cell.

[0018] According to some embodiments of the present application, along the first direction, a distance from one end of the second thickened portion away from the opening to the opening is L1, satisfying 0<L1≤20mm.

[0019] In the above scheme, along the first direction, by arranging a second thickened portion in the corner area within 20 mm below the opening, the strength of the portion of the corner area corresponding to the opening can be effectively improved, and the risk of cracking in the corner area due to stress concentration on the portion of the corner area corresponding to the opening during the shell manufacturing process caused by thickening the first wall can be reduced, thereby making the battery cell have higher reliability.

[0020] According to some embodiments of the present application, along the first direction, a distance from one end of the first thickened portion away from the opening to the opening is L2, satisfying 0<L2≤20mm.

[0021] In the above scheme, along the first direction, by arranging a first thickened portion in the area of ​​the first wall within 20 mm below the opening, the strength of the portion of the first wall corresponding to the opening can be effectively improved, and the risk of the first wall being easily cracked by impact due to the formation of a heat-affected zone with lower strength caused by the welding of the shell at the portion corresponding to the opening can be reduced, thereby making the battery cell have higher reliability.

[0022] According to some embodiments of the present application, an area of ​​an outer surface of the first wall is greater than an area of ​​an outer surface of the second wall.

[0023] In the above solution, by providing the first thickened portion on the first wall with a larger outer surface area, the risk of the shell being easily cracked by impact can be effectively improved, so that the battery cell has higher reliability.

[0024] According to some embodiments of the present application, along the second direction, the housing includes two first walls arranged opposite to each other, and along the third direction, the housing includes two second walls arranged opposite to each other, and the second direction, the third direction and the first direction are perpendicular to each other. Adjacent first walls and second walls are connected by corresponding corner areas, and the first walls, the second walls and the corner areas together form an opening.

[0025] In the above solution, the shell can be a square structure. By thickening the two wall portions arranged opposite to each other along the second direction, that is, providing the first thickened portion, the structural strength of the shell can be effectively improved and the risk of cracking of the shell due to impact can be reduced; at the same time, by thickening the corner area between the two adjacent wall portions, that is, providing the second thickened portion, the problem of cracking in the corner area due to stress concentration can be improved, so that the battery cell has higher reliability.

[0026] According to some embodiments of the present application, the second wall has a third main body portion and a third thickened portion arranged along the first direction, the third main body portion is farther away from the opening than the third thickened portion, and the maximum thickness of the third thickened portion is greater than the thickness of the third main body portion.

[0027] In the above solution, by providing a third thickened portion with a larger maximum thickness on the second wall, the risk of a heat-affected zone with lower strength formed by welding of the shell, which causes the second wall to crack due to insufficient strength when impacted, can be improved, so that the battery cell has higher reliability.

[0028] According to some embodiments of the present application, the maximum thickness of the second thickened portion is greater than the maximum thickness of the third thickened portion.

[0029] In the above scheme, by setting the maximum thickness of the second thickened portion to be greater than the maximum thickness of the third thickened portion, the strength of the portion of the corner area corresponding to the opening can be effectively improved. On the one hand, the overall thickness of the shell can be effectively increased to reduce the risk of cracking of the shell due to impact. On the other hand, the problem of stress concentration in the corner area during the shell manufacturing process leading to cracking of the corner area can be effectively improved, so that the battery cell has higher reliability.

[0030] According to some embodiments of the present application, the maximum thickness of the second thickened portion is T1, the thickness of the second main body portion is T2, the maximum thickness of the third thickened portion is t3, and the thickness of the third main body portion is t4, satisfying E≥G, E=(T1-T2) / T2, G=(t3-t4) / t4.

[0031] In the above scheme, by limiting the degree of thickening E of the second thickened portion compared to the second main body portion to be no less than the degree of thickening G of the third thickened portion compared to the third main body portion, the problem of stress concentration at the corner portion corresponding to the opening during the shell manufacturing process due to the provision of the third thickened portion, resulting in cracking in the corner area, can be effectively improved, so that the battery cell has higher reliability.

[0032] According to some embodiments of the present application, along the first direction, a distance from one end of the third thickened portion away from the opening to the opening is L3, satisfying 0<L3≤20mm.

[0033] In the above scheme, along the first direction, by setting a third thickened portion in the area of ​​the second wall within 20 mm below the opening, the strength of the second wall corresponding to the opening can be effectively improved, reducing the risk of the second wall being easily cracked by impact, so that the battery cell has higher reliability.

[0034] According to some embodiments of the present application, the battery cell further includes an end cover, which closes the opening. The third thickened portion includes a first section and a second section connected to each other, the first section, the second section and the third body section are sequentially distributed along the first direction, the maximum thickness of the second section is greater than the thickness of the third body section, the maximum thickness of the second section is greater than the maximum thickness of the first section, and the end cover is connected to the first section.

[0035] In the above solution, by setting the thickness of the second section of the third thickened portion to be greater than the thickness of the third main body portion, the strength of the second wall can be effectively improved, and the risk of the second wall cracking due to impact can be reduced, so that the battery cell has higher reliability.

[0036] According to some embodiments of the present application, a first step surface is formed between the second section and the first section, and the end cover overlaps the first step surface.

[0037] In the above scheme, the first step surface formed between the second section and the first section can enable the end cover to overlap the first step surface, thereby facilitating the positioning and assembly of the end cover. At the same time, the first step surface can support the end cover and reduce the risk of collapse of the end cover, thereby making the battery cell have higher reliability.

[0038] According to some embodiments of the present application, the battery cell also includes an end cover, which closes the opening; the second thickened portion includes a third segment and a fourth segment that are connected to each other, the third segment, the fourth segment and the second main body are distributed sequentially along the first direction, the maximum thickness of the fourth segment is greater than the thickness of the second main body, the maximum thickness of the fourth segment is greater than the maximum thickness of the third segment, and the end cover is connected to the third segment.

[0039] In the above solution, by setting the thickness of the fourth section of the second thickened portion to be greater than the thickness of the second main body portion, the strength of the corner area can be effectively improved, reducing the risk of cracking in the corner area due to impact or stress concentration during demolding, so that the battery cell has higher reliability.

[0040] According to some embodiments of the present application, a second step surface is formed between the fourth section and the third section, and the end cover overlaps the second step surface.

[0041] In the above scheme, the second step surface formed between the fourth section and the third section can enable the end cover to overlap the second step surface, thereby facilitating the positioning and assembly of the end cover; at the same time, the second step surface supports the end cover, which can reduce the risk of end cover collapse, thereby making the battery cell have higher reliability.

[0042] According to some embodiments of the present application, the battery cell also includes an end cover, which is welded to the second thickened portion to form a fusion zone, and the average grain size of the second thickened portion other than the fusion zone is larger than the average grain size of the second main body portion, and the average grain size is the average grain size of the grains in the first direction.

[0043] In the above scheme, by limiting the average grain size of the second thickened portion other than the welding zone to be larger than the average grain size of the second main body portion, it is beneficial to enhance the strength of the corner zone, so that the second thickened portion has higher strength, reduces the risk of cracking of the corner zone near the welding zone due to impact and the risk of cracking of the corner zone due to stress concentration during demolding, and makes the battery cell have higher reliability.

[0044] According to some embodiments of the present application, on a cross-section of the corner area parallel to the first direction, in a portion of the second thickened portion located below the fusion zone, the number of grains in the width direction of the cross-section is greater than or equal to 15.

[0045] In the above solution, in the width direction of the cross section, the number of grains is greater than or equal to, which is beneficial to enhancing the strength of the second thickened portion, reducing the risk of shell cracking, and improving the reliability of the battery cell.

[0046] According to some embodiments of the present application, the average grain size of the second thickened portion excluding the fusion zone is in the range of 70 μm to 1200 μm; and / or, the average grain size of the second main body portion is in the range of 30 μm to 1000 μm; and / or, the maximum wall thickness of the end cover is in the range of 0.25 mm to 3 mm.

[0047] In the above solution, the average grain size of the second thickened portion and / or the average grain size of the second main body portion satisfies the above relationship, which is beneficial to enhancing the strength of the second thickened portion, so that the battery cell has higher reliability.

[0048] In a second aspect, the present application further provides a battery, comprising the battery cell of the first aspect.

[0049] In a third aspect, the present application further provides an energy storage device, comprising the battery cell of the first aspect.

[0050] In a fourth aspect, the present application further provides an electrical device, comprising the battery cell of the first aspect, for providing electrical energy.

[0051] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. 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 related drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 A schematic diagram of a vehicle in some embodiments of the present application;

[0054] Figure 2 A schematic diagram of an energy storage device in some embodiments of the present application;

[0055] Figure 3A three-dimensional exploded view of a battery in some embodiments of the present application;

[0056] Figure 4 A three-dimensional exploded view of a local structure of a battery cell in some embodiments of the present application;

[0057] Figure 5 A front view of a battery cell in some embodiments of the present application;

[0058] Figure 6 for Figure 5 Sectional view from the AA direction;

[0059] Figure 7 for Figure 6 The enlarged view of point B in the middle;

[0060] Figure 8 for Figure 5 Sectional view from CC direction;

[0061] Fig. 9 for Figure 8 The enlarged view of point D in the middle;

[0062] Fig.10 Schematic diagram of the internal structure of a battery cell in some embodiments of the present application;

[0063] Fig.11 for Fig.10 The enlarged view of the H in the middle;

[0064] Fig.12 for Figure 4 Enlarged view of L in the middle;

[0065] Fig.13 Schematic diagram of end caps and corner areas in some embodiments of the present application.

[0066] Icon: 100-battery; 10-battery cell; 11-housing; 12-electrode assembly; 13-electrode terminal; 11a-opening; 14-end cover; 110-first wall; 1100-first body; 1101-first thickened portion; 112-corner area; 1120-second body; 1121-second thickened portion; 1121a-third section; 1121b-fourth section; 1121c-second step surface; 113-third section Two walls; 1130-third main body; 1131-third thickened portion; 1131a-first section; 1131b-second section; 1131c-first step surface; 114-fusion zone; 20-box; 21-first box part; 22-second box part; z-first direction; x-second direction; y-third direction; 1000-vehicle; 200-controller; 300-motor; 2000-energy storage device; 2001-cabinet. DETAILED DESCRIPTION

[0067] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0068] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0069] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0070] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0071] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0072] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0073] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0074] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0075] In the present 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., which are not limited in the embodiments of the present application. Battery cells may be rectangular or in other shapes, etc., which are not limited in the embodiments of the present application. The battery mentioned in the embodiments of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. The battery generally includes a casing for encapsulating one or more battery cells. The casing can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0076] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed 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 (for example, deintercalation). 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 a positive electrode ear. 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. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode collector. The negative electrode collector not coated with the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer. The negative electrode collector not coated with the negative electrode active material layer serves as a negative electrode ear. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon, etc. In order to ensure that a large current can pass without melting, the number of positive pole ears is multiple and stacked together, and the number of negative pole ears is multiple and stacked together. The material of the isolation membrane may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly may be a winding structure or a laminated structure, and the embodiments of the present application are not limited to this. The battery cell also includes a shell, an end cover, and the electrode assembly and the electrolyte are arranged in the shell. Along the first direction, the shell is formed with an opening, and the end cover is welded to the shell to close the opening of the shell. In some embodiments, along the circumference of the opening, the shell includes a first wall, a corner area and a second wall connected in sequence, the first wall and the second wall are adjacent, and the first wall and the second wall are transitionally connected through the corner area.

[0077] The development of battery technology must consider many design factors at the same time, such as performance parameters such as energy density, cycle life, discharge capacity, charge and discharge rate, and the reliability of the battery. For battery cells, after the end cap and the shell are welded, a heat-affected zone that reduces the strength of the shell is often formed below the molten pool, causing the shell to crack when the battery cell is impacted or expanded internally, resulting in battery failure. In order to improve this problem, the wall of the battery shell is currently thickened or partially thickened, for example, the first wall of the shell is thickened at the position corresponding to the opening to increase the strength of the shell. However, this type of shell is made by a stretching forming process. When the shell is elastically demolded, the stress will be concentrated in the corner area corresponding to the opening, which can easily cause the corner area to crack, affecting the reliability of the battery cell, and thus affecting the reliability of the battery.

[0078] In view of this, in order to improve the problem that the shell cracks in the corner area due to stress concentration during elastic demolding, which affects the reliability of the battery cell, some embodiments of the present application provide a battery cell, which includes a shell. An opening is formed at the end of the shell along the first direction. Along the circumference of the opening, the shell includes a first wall, a corner area, and a second wall connected in sequence. The first wall has a first main body portion and a first thickened portion arranged along the first direction, the first main body portion is farther away from the opening than the first thickened portion, and the maximum thickness of the first thickened portion is greater than the thickness of the first main body portion. Among them, the corner area has a second main body portion and a second thickened portion arranged along the first direction, the second main body portion is farther away from the opening than the second thickened portion, and the maximum thickness of the second thickened portion is greater than the thickness of the second main body portion.

[0079] In the above scheme, by providing the first thickened portion with a larger maximum thickness on the first wall, the risk of the first wall cracking due to insufficient strength when impacted due to the formation of a heat-affected zone with a lower strength due to welding of the shell can be improved, so that the battery has a higher reliability. At the same time, by providing the second thickened portion with a larger maximum thickness in the corner area, the strength of the corner area corresponding to the opening can be improved, and the problem of the shell cracking in the corner area due to stress concentration during elastic demoulding caused by the provision of the first thickened portion can be improved, so that the battery cell has a higher reliability.

[0080] The technical solutions described in the embodiments of the present application are applicable to batteries, energy storage devices having battery modules, and electrical devices using battery modules.

[0081] The energy storage device may include multiple battery cells, which may be connected in series, in parallel or in mixed connection. The energy storage device may be a device capable of storing electrical energy, such as an energy storage cabinet or an energy storage box.

[0082] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a new energy vehicle, which may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; 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, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0083] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle 1000 as an example.

[0084] Figure 1 Schematic diagram of a vehicle 1000 in some embodiments of the present application.

[0085] A controller 200, a motor 300 and a battery 100 may be disposed inside the vehicle 1000, and the controller 200 is used to control the battery 100 to power the motor 300. For example, the battery 100 may be disposed at the bottom, front or rear of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000, for the circuit system of the vehicle 1000, for example, for the working power requirements during the start-up, navigation and operation of the vehicle 1000. In another embodiment of the present application, the battery 100 may not only be used as an operating power source for the vehicle 1000, but may also be used 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.

[0086] Figure 2 Schematic diagram of energy storage device in some embodiments of the present application. Energy storage device 2000 may be a device for storing electric energy, for example, energy storage device 2000 may include an energy storage cabinet, and the energy storage cabinet includes a cabinet body 2001 and one or more batteries 100 disposed in the cabinet body. Cabinet body 2001 may include a cabinet body and a cabinet door, one or more batteries 100 are disposed in the cabinet body, and the cabinet door closes the opening of the cabinet body so that one or more batteries 100 are in a closed space, reducing the interference effect of external substances on the battery 100.

[0087] See also Figure 3 , Figure 3 It is a three-dimensional exploded view of the battery 100 in some embodiments of the present application.

[0088] The battery 100 includes a battery cell 10 and a box 20, and the battery cell 10 is accommodated in the box 20. The box 20 is used to provide a storage space for the battery cell 10, and the box 20 can adopt a variety of structures. In some embodiments, the box 20 may include a first box portion 21 and a second box portion 22, and the first box portion 21 and the second box portion 22 cover each other, and the first box portion 21 and the second box portion 22 jointly define a storage space for accommodating the battery cell 10. The second box portion 22 may be a hollow structure with an opening 11a at one end, and the first box portion 21 may be a plate-like structure, and the first box portion 21 covers the opening 11a side of the second box portion 22, so that the first box portion 21 and the second box portion 22 jointly define a storage space; the first box portion 21 and the second box portion 22 may also be hollow structures with an opening 11a on one side, and the opening 11a side of the first box portion 21 covers the opening 11a side of the second box portion 22. Of course, the box body 20 formed by the first box body portion 21 and the second box body portion 22 can be in various shapes, such as a cylinder, a cuboid, etc.

[0089] In the battery 100 , there may be one or more battery cells 10 , and each battery cell 10 may be fixed to the case 20 by a connector (such as a bolt), or each battery cell 10 may be fixed to the case 20 by bonding.

[0090] Some embodiments of the present application provide a battery cell 10, see Figure 4-Figure 11 , Figure 4 This is a three-dimensional exploded view of a local structure of a battery cell 10 in some embodiments of the present application. Figure 5 This is a front view of a battery cell 10 in some embodiments of the present application. Figure 6 for Figure 5 Sectional view from the AA direction, Figure 7 for Figure 6 The enlarged view of point B in the middle. Figure 8 for Figure 5 Sectional view from CC direction, Fig. 9 for Figure 8 The enlarged view of D in the middle. Fig.10 This is a schematic diagram of the internal structure of a battery cell 10 in some embodiments of the present application. Fig.11 for Fig.10 Enlarged view of point H in the middle.

[0091] The battery cell 10 includes a shell 11. An opening 11a is formed at the end of the shell 11 along the first direction z. Along the circumference of the opening 11a, the shell 11 includes a first wall 110, a corner area 112, and a second wall 113 connected in sequence. The first wall 110 has a first body portion 1100 and a first thickened portion 1101 arranged along the first direction z, the first body portion 1100 is farther away from the opening 11a than the first thickened portion 1101, and the maximum thickness of the first thickened portion 1101 is greater than the thickness of the first body portion 1100. Among them, the corner area 112 has a second body portion 1120 and a second thickened portion 1121 arranged along the first direction z, the second body portion 1120 is farther away from the opening 11a than the second thickened portion 1121, and the maximum thickness of the second thickened portion 1121 is greater than the thickness of the second body portion 1120.

[0092] In some embodiments, the battery cell 10 may include a shell 11 and an end cap 14. Along the first direction z, the shell 11 has an opening 11a, the electrode assembly 12 is disposed inside the shell 11, and the end cap 14 is connected to the shell 11 to close the opening 11a, so that the electrode assembly 12 is located in a closed space. In some embodiments, the end cap 14 may be provided with an electrode terminal 13, and the electrode terminal 13 is connected to the pole ear of the electrode assembly 12 to achieve the output and input of current. In some embodiments, the end cap 14 may be provided with an injection hole, and the electrolyte may be injected into the shell 11 through the injection hole. In some embodiments, the end cap 14 may be riveted, welded or threadedly connected to the shell 11.

[0093] In some embodiments, along the circumference of the opening 11a of the shell 11, the shell 11 may include a plurality of interconnected wall portions, for example, along the circumference of the opening 11a, the shell 11 includes a first wall 110, a corner area 112 and a second wall 113 connected in sequence, wherein the first wall 110 and the second wall 113 are arranged adjacent to each other, and the first wall 110 and the second wall 113 are transitionally connected through the corner area 112. Exemplarily, when the shell 11 is square or quasi-square, along the second direction x, the shell 11 has two first walls 110 arranged opposite to each other, and along the third direction y, the shell 11 has two second walls 113 arranged opposite to each other, the second direction x and the third direction y are perpendicular to each other, and the adjacent first walls 110 and the second walls 113 are connected through the corresponding corner area 112, and the first wall 110, the second wall 113 and the corner area 112 together enclose the opening 11a. In some embodiments, the cross section of the corner area 112 may be arc-shaped so that the first wall 110 and the second wall 113 transition in a circular arc. In other embodiments, the cross-section of the corner area 112 may not be an arc shape, but may be a polygonal shape, so that the first wall 110 and the second wall 113 have a smooth transition.

[0094] In some embodiments, the first direction z may be parallel to the height direction of the battery cell 10 , the second direction x may be the thickness direction of the battery cell 10 , and the third direction y may be the width direction of the battery cell 10 .

[0095] In some embodiments, the area of ​​the outer surface of the first wall 110 may be greater than the area of ​​the outer surface of the second wall 113. In other embodiments, the area of ​​the outer surface of the first wall 110 may be less than the area of ​​the outer surface of the second wall 113. In other embodiments, the area of ​​the outer surface of the first wall 110 may be equal to the area of ​​the outer surface of the second wall 113.

[0096] In some embodiments, the shell 11 can be made by a process such as a stretching forming process. The stretching forming process may include a stretching process and a demolding process. Generally, the stretching process refers to: in the stretching station, stress is applied to the metal sheet to cause it to deform. During the stretching process, it is necessary to control parameters such as stress magnitude, speed and time to avoid problems such as breakage or uneven stress of the metal sheet. Hydraulic or mechanical drive is usually used to apply the stretching force. Generally, the demolding process is also called elastic demolding, which may refer to: after the stretching is completed, the finished product is slid out of the mold. Pneumatic demolding or mechanical demolding is usually used.

[0097] “The first wall 110 has a first main body portion 1100 and a first thickened portion 1101 arranged along a first direction z, and the first main body portion 1100 is farther away from the opening 11a than the first thickened portion 1101” can be understood as, in the first direction z, the first main body portion 1100 and the first thickened portion 1101 are arranged with each other, and the first main body portion 1100 is farther away from the opening 11a than the first thickened portion 1101.

[0098] Exemplarily, one possibility is that the first main body portion 1100 and the first thickened portion 1101 are connected in sequence along the first direction z, the first thickened portion 1101 is away from the end of the first main body portion 1100 to form a portion of the opening 11a, and the first thickened portion 1101 is connected to the end cover; or, a second possibility is that the first wall 110 also includes a first connecting section, the first connecting section, the first thickened portion 1101 and the first main body portion 1100 are distributed in sequence along the first direction z, the end of the first connecting section forms a portion of the opening 11a, the first connecting section can be connected to the end cover 14, and the thickness of the first connecting section can be greater than, equal to or less than the maximum thickness of the first thickened portion 1101.

[0099] “The maximum thickness of the first thickened portion 1101 is greater than the thickness of the first main body 1100” can be understood as that the maximum thickness of the first thickened portion 1101 is greater than the thickness of the first main body 1100, and can also be understood as that the strength of the first thickened portion 1101 is greater than the strength of the first body. In some embodiments, the first thickened portion 1101 is a structure of equal wall thickness, and its wall thickness can be greater than the thickness of the first main body 1100. In other embodiments, the first thickened portion 1101 may not be a structure of equal wall thickness, and the wall thickness of the portion with the largest wall thickness is greater than the maximum wall thickness of the first main body 1100. In some embodiments, the first thickened portion 1101 is connected to the first main body 1100, and the wall thickness of the junction of the first thickened portion 1101 and the first main body 1100 can gradually increase so that the first thickened portion 1101 and the first main body 1100 have a smooth transition.

[0100] In some embodiments, the first thickened portion 1101 protrudes from the inner side of the first body portion 1100, that is, the portion of the first thickened portion 1101 protruding from the first body portion 1100 can be located inside the housing 11. In other embodiments, the first thickened portion 1101 protrudes from the outer side of the first body portion 1100, that is, the portion of the first thickened portion 1101 protruding from the first body portion 1100 can be located outside the housing 11. In other embodiments, the first thickened portion 1101 can protrude from both the outer side and the inner side of the first body portion 1100, that is, a portion of the first thickened portion 1101 protruding from the first body portion 1100 can be located outside the housing 11, and a portion can be located inside the housing 11.

[0101] In some embodiments, the first body portion 1100 may be a structure with uniform wall thickness. In other embodiments, the wall thickness of the first body portion 1100 may be unevenly distributed, and may be a structure with unequal wall thickness.

[0102] “The corner area 112 has a second main body portion 1120 and a second thickened portion 1121 arranged along a first direction z, and the second main body portion 1120 is farther away from the opening 11a than the second thickened portion 1121” can be understood as, in the first direction z, the second main body portion 1120 and the second thickened portion 1121 are arranged with each other, and the second main body portion 1120 is farther away from the opening 11a than the second thickened portion 1121.

[0103] Exemplarily, one possibility is that the second main body portion 1120 and the second thickened portion 1121 are sequentially connected along the first direction z, the second thickened portion 1121 is away from the end of the second main body portion 1120 to form a portion of the opening 11a, and the second thickened portion 1121 is connected to the end cover; or, a second possibility is that the corner area 112 also includes a second connecting section, the second connecting section, the second main body portion 1120 and the second thickness portion are sequentially distributed along the first direction z, the end of the second connecting section forms a portion of the opening 11a, and the second connecting section can be connected to the end cover.

[0104] “The maximum thickness of the second thickened portion 1121 is greater than the thickness of the second body portion 1120” can be understood as that the maximum thickness of the second thickened portion 1121 is greater than the thickness of the second body portion 1120, and can also be understood as that the strength of the second thickened portion 1121 is greater than the strength of the second body. In some embodiments, the second thickened portion 1121 is a structure of equal wall thickness, and its wall thickness can be greater than the thickness of the second body portion 1120. In other embodiments, the second thickened portion 1121 may not be a structure of equal wall thickness, and the wall thickness of the portion with the largest wall thickness is greater than the maximum wall thickness of the second body portion 1120. In some embodiments, the second thickened portion 1121 is connected to the second body portion 1120, and the wall thickness of the junction of the second thickened portion 1121 and the second body portion 1120 can gradually increase so that the second thickened portion 1121 and the second body portion 1120 have a smooth transition.

[0105] In some embodiments, the second body portion 1120 may be a structure with uniform wall thickness. In other embodiments, the wall thickness of the second body portion 1120 may be unevenly distributed, and may be a structure with unequal wall thickness.

[0106] In some embodiments, the second thickened portion 1121 protrudes from the inner side of the second body portion 1120, that is, the portion of the second thickened portion 1121 protruding from the second body portion 1120 can be located inside the housing 11. In other embodiments, the second thickened portion 1121 protrudes from the outer side of the second body portion 1120, that is, the portion of the second thickened portion 1121 protruding from the second body portion 1120 can be located outside the housing 11. In other embodiments, the second thickened portion 1121 can protrude from both the outer side and the inner side of the second body portion 1120, that is, a portion of the second thickened portion 1121 protruding from the second body portion 1120 can be located outside the housing 11, and a portion can be located inside the housing 11.

[0107] In some embodiments, there is no limit to the relationship between the maximum thickness of the first thickened portion 1101 and the maximum thickness of the second thickened portion 1121, and possible solutions include: the maximum thickness of the first thickened portion 1101 is less than the maximum thickness of the second thickened portion 1121; the maximum thickness of the first thickened portion 1101 is greater than the maximum thickness of the second thickened portion 1121; or, the maximum thickness of the first thickened portion 1101 is equal to the maximum thickness of the second thickened portion 1121.

[0108] In the above scheme, by providing the first thickened portion 1101 with a larger maximum thickness on the first wall 110, the problem that the heat-affected zone of the shell 11 with a lower strength is formed due to welding, causing the first wall 110 to crack due to insufficient strength when impacted, can be improved, so that the battery 100 has higher reliability. At the same time, by providing the second thickened portion 1121 with a larger maximum thickness in the corner area 112, the strength of the corner area 112 corresponding to the opening 11a can be improved, and the problem that the stress of the shell 11 is concentrated on the corner area 112 corresponding to the opening 11a during demolding due to the provision of the first thickened portion 1101, causing the corner area 112 to crack, can be improved, so that the battery cell 10 has higher reliability.

[0109] According to some embodiments of the present application, the maximum thickness of the second thickened portion 1121 is greater than the maximum thickness of the first thickened portion 1101 .

[0110] “The maximum thickness of the second thickened portion 1121 is greater than the maximum thickness of the first thickened portion 1101” can be understood as that the maximum thickness of the thickened portion of the corner area 112 is greater than the maximum thickness of the thickened portion of the first wall 110 , and can also be understood as that the strength of the second thickened portion 1121 is greater than the strength of the first thickened portion 1101 .

[0111] In some embodiments, the minimum thickness of the second thickened portion 1121 may be greater than the maximum thickness of the first thickened portion 1101. In other embodiments, the minimum thickness of the second thickened portion 1121 may be less than or equal to the maximum thickness of the first thickened portion 1101. In other embodiments, the minimum thickness of the second thickened portion 1121 may be less than or equal to the minimum thickness of the first thickened portion 1101.

[0112] In the above scheme, by setting the maximum thickness of the second thickened portion 1121 to be greater than the maximum thickness of the first thickened portion 1101, the strength of the corner area 112 corresponding to the opening 11a can be effectively improved. On the one hand, the overall thickness of the shell 11 can be effectively increased to reduce the risk of the shell 11 being cracked due to impact. On the other hand, the stress concentration during the manufacturing process of the shell 11 can be effectively improved, which causes the problem of cracking in the corner area 112, so that the battery cell 10 has higher reliability.

[0113] In other embodiments, the maximum thickness of the second thickened portion 1121 may be less than the maximum thickness of the first thickened portion 1101 ; in other embodiments, the maximum thickness of the second thickened portion 1121 may be less than the minimum thickness of the first thickened portion 1101 .

[0114] According to some embodiments of this application, see Figure 7 and Fig. 9 The maximum thickness of the second thickened portion 1121 is T1, the thickness of the second main body portion 1120 is T2, the maximum thickness of the first thickened portion 1101 is t1, and the thickness of the first main body portion 1100 is t2, satisfying E≥F, E=(T1-T2) / T2, and F=(t1-t2) / t2.

[0115] In some embodiments, the corner area 112 of the shell 11 can be regarded as a part that is locally thickened with the second main body portion 1120 as a reference to form the second thickened portion 1121, T1-T2 is the difference between the maximum thickness of the second thickened portion 1121 and the thickness of the second main body portion 1120, and E is the difference between the maximum thickness of the second thickened portion 1121 and the thickness of the second main body portion 1120 divided by the thickness of the second main body portion 1120, that is, E can be regarded as the degree of thickening of the second thickened portion 1121 compared with the second main body portion 1120.

[0116] In some embodiments, the first wall 110 of the shell 11 can be regarded as a part that is locally thickened based on the first main body 1100 to form the first thickened portion 1101, t1-t2 is the difference between the maximum thickness of the first thickened portion 1101 and the thickness of the first main body 1100, F is the difference between the maximum thickness of the first thickened portion 1101 and the thickness of the first main body 1100 divided by the thickness of the first main body 1100, that is, F can be regarded as the degree of thickening of the first thickened portion 1101 compared with the first main body 1100.

[0117] “E≥F” can be understood as that the degree of thickening of the second thickened portion 1121 compared to the second portion is greater than or equal to the degree of thickening of the first thickened portion 1101 compared to the first main body portion 1100 .

[0118] In the above scheme, by limiting the degree E of thickening of the second thickened portion 1121 compared with the second main body portion 1120 to be no less than the degree F of thickening of the first thickened portion 1101 compared with the first main body portion 1100, the problem of stress concentration during the manufacturing process of the shell 11 causing cracks in the corner area 112 due to the provision of the first thickened portion 1101 can be effectively improved, so that the battery cell 10 has higher reliability.

[0119] In other embodiments, the second thickened portion 1121 is thicker than the second portion than the first thickened portion 1101 is thicker than the first body portion 1100 .

[0120] According to some embodiments of the present application, the maximum thickness of the second thickened portion 1121 is T1, and the thickness of the second body portion 1120 is T2, satisfying 0<E<30%, E=(T1-T2) / T2.

[0121] In some embodiments, the corner area 112 of the shell 11 can be regarded as a part that is locally thickened with the second main body portion 1120 as a reference to form the second thickened portion 1121, T1-T2 is the difference between the maximum thickness of the second thickened portion 1121 and the thickness of the second main body portion 1120, and E is the difference between the maximum thickness of the second thickened portion 1121 and the thickness of the second main body portion 1120 divided by the thickness of the second main body portion 1120, that is, E can be regarded as the degree of thickening of the second thickened portion 1121 compared with the second main body portion 1120.

[0122] In some embodiments, the value of E can be greater than 0 and less than 30%. For example, E can be 1%, 2%, 3%, 4%...28%, 29%, any value between two adjacent values, or any value between 29% and 30%.

[0123] In some embodiments, T2 may be 0.6 mm; T1 may be a value greater than 0.6 mm, for example, T1 may be 0.65%, 0.7% or 0.75%, and the corresponding values ​​of E are 8.3%, 16.7% and 25%, respectively.

[0124] In the above scheme, by limiting the degree E of thickening of the second thickened portion 1121 compared to the second main body portion 1120, on the one hand, the strength of the corner area 112 can be improved and the risk of cracking of the corner area 112 due to stress concentration can be reduced; on the other hand, the risk of bulging of the corner area 112 and deformation of the outer shell due to excessive stress can be reduced, so that the battery cell 10 has higher reliability.

[0125] According to some embodiments of the present application, 0<E≤16.7% is satisfied.

[0126] In some embodiments, the value of E may be greater than 0 and less than or equal to 16.7%. For example, E may be 1%, 2%, 3%, 4%...16%, 16.7% or any value between two adjacent values.

[0127] In the above scheme, by limiting the degree E of thickening of the second thickened portion 1121 compared with the second main body portion 1120 to no more than 16.7%, on the one hand, it can take into account the improvement of the problems of cracking caused by stress concentration and deformation caused by excessive stress; on the other hand, it can effectively control the weight of the shell 11, which is beneficial to the improvement of the weight energy density of the battery cell 10.

[0128] According to some embodiments of the present application, along the first direction z, a distance from one end of the second thickened portion 1121 away from the opening 11 a to the opening 11 a is L1, satisfying 0<L1≤20 mm.

[0129] In some embodiments, the value of L1 can be a value greater than 0 and less than or equal to 20 mm. For example, the value of L1 can be 1 mm, 2 mm, 3 mm, 4 mm...15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm or any value between two adjacent values, or any value between 0 mm and 1 mm.

[0130] In some embodiments, the first direction z can be regarded as the up and down direction, and "the distance from the end of the second thickened portion 1121 away from the opening 11a to the opening 11a is L1" can be understood as, the second main body portion 1120 is L1 below the opening, and the second thickened portion 1121 is above the second main body portion 1120, or it can be understood that along the first direction z, the portion away from the opening 11a can define a dividing line, the second thickened portion 1121 is above the dividing line, and the second main body portion 1120 is below the dividing line.

[0131] In the above scheme, along the first direction z, by setting the second thickened portion 1121 in the corner area 112 within 20 mm below the opening 11a, the strength of the corner area 112 corresponding to the opening 11a can be effectively improved, and the risk of cracking of the corner area 112 due to stress concentration in the corner area 112 corresponding to the opening 11a during the manufacturing process of the shell 11 caused by thickening the first wall 110 is reduced, so that the battery cell 10 has higher reliability.

[0132] According to some embodiments of the present application, along the first direction z, a distance from one end of the first thickened portion 1101 away from the opening 11 a to the opening 11 a is L2, satisfying 0<L2≤20 mm.

[0133] In some embodiments, the value of L1 can be a value greater than 0 and less than or equal to 20 mm. For example, the value of L1 can be 1 mm, 2 mm, 3 mm, 4 mm...15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm or any value between two adjacent values, or any value between 0 mm and 1 mm.

[0134] In some embodiments, the first direction z can be regarded as the up and down direction, and "the distance from the end of the first thickened portion 1101 away from the opening 11a to the opening 11a is L2" can be understood as, the first main body portion 1100 is L2 below the opening, and the first thickened portion 1101 is above the first main body portion 1100, or it can be understood that along the first direction z, the portion away from the opening 11a can define a dividing line, the first thickened portion 1101 is above the dividing line, and the first main body portion 1100 is below the dividing line.

[0135] In the above scheme, along the first direction z, by setting the second thickened portion 1121 in the corner area 112 within 20 mm below the opening 11a, the strength of the corner area 112 corresponding to the opening 11a can be effectively improved, and the risk of cracking of the corner area 112 due to stress concentration in the corner area 112 corresponding to the opening 11a during the manufacturing process of the shell 11 caused by thickening the first wall 110 is reduced, so that the battery cell 10 has higher reliability.

[0136] According to some embodiments of the present application, an area of ​​an outer surface of the first wall 110 is greater than an area of ​​an outer surface of the second wall 113 .

[0137] In some embodiments, the outer surface of the first wall 110 may be a large surface of the battery cell 10 . When the battery cell 10 is charged or discharged, the expansion force generated inside the battery cell 10 mainly acts on the first wall 110 .

[0138] In the above solution, by providing the first thickened portion 1101 on the first wall 110 with a larger outer surface area, the risk of the shell 11 being easily cracked by impact can be effectively improved, so that the battery cell 10 has higher reliability.

[0139] In some other embodiments of the present application, the area of ​​the outer surface of the first wall 110 is equal to the area of ​​the outer surface of the second wall 113 ; or, the area of ​​the outer surface of the first wall 110 is smaller than the area of ​​the outer surface of the second wall 113 .

[0140] According to some embodiments of this application, see Figure 4 Along the second direction x, the housing 11 includes two first walls 110 disposed opposite to each other, and along the third direction y, the housing 11 includes two second walls 113 disposed opposite to each other, and the second direction x, the third direction y and the first direction z are perpendicular to each other. The adjacent first walls 110 and second walls 113 are connected by corresponding corner areas 112, and the first walls 110, the second walls 113 and the corner areas 112 together form an opening 11a.

[0141] In some embodiments, the housing 11 may be in a rectangular parallelepiped shape, and its main structure includes two opposite first walls 110 and two opposite second walls 113, and the first walls 110 and the second walls 113 are arranged adjacent to each other. The adjacent first walls 110 and the second walls 113 are transitionally connected by a corner area 112. In some embodiments, the corner area 112 may be an arc-shaped portion.

[0142] In the above solution, the shell 11 can be a square structure. By thickening the two walls arranged opposite to each other along the second direction x, that is, providing the first thickened portion 1101, the structural strength of the shell 11 can be effectively improved, and the risk of the shell 11 being cracked by impact can be reduced; at the same time, by thickening the corner area 112 between the two adjacent walls, that is, providing the second thickened portion 1121, the problem of cracking in the corner area 112 due to stress concentration can be improved, so that the battery cell 10 has higher reliability.

[0143] According to some embodiments of this application, see Figure 5-Figure 9 The second wall 113 has a third main body portion 1130 and a third thickened portion 1131 arranged along the first direction z. The third main body portion 1130 is farther away from the opening 11a than the third thickened portion 1131 . The maximum thickness of the third thickened portion 1131 is greater than the thickness of the third main body portion 1130 .

[0144] “The second wall 113 has a third main body portion 1130 and a third thickened portion 1131 arranged along the first direction z, and the third main body portion 1130 is farther away from the opening 11a than the third thickened portion 1131” can be understood as, in the first direction z, the third main body portion 1130 and the third thickened portion 1131 are arranged with each other, and the third main body portion 1130 is farther away from the opening 11a than the third thickened portion 1131.

[0145] Exemplarily, one possibility is that the third main body portion 1130 and the third thickened portion 1131 are sequentially connected along the first direction z, the third thickened portion 1131 is away from the end of the third main body portion 1130 to form a portion of the opening 11a, and the third thickened portion 1131 is connected to the end cover; or, a second possibility is that the second wall 113 also includes a third connecting segment, the third connecting segment, the third main body portion 1130 and the third thickness portion are sequentially distributed along the first direction z, the end of the third connecting segment forms a portion of the opening 11a, and the third connecting segment can be connected to the end cover 14.

[0146] “The maximum thickness of the third thickened portion 1131 is greater than the thickness of the third main body portion 1130” can be understood as that the maximum thickness of the third thickened portion 1131 is greater than the thickness of the third main body portion 1130, and can also be understood as that the strength of the third thickened portion 1131 is greater than the strength of the third body. In some embodiments, the third thickened portion 1131 is a structure of equal wall thickness, and its wall thickness can be greater than the thickness of the third main body portion 1130. In other embodiments, the third thickened portion 1131 may not be a structure of equal wall thickness, and the wall thickness of the portion with the largest wall thickness is greater than the maximum wall thickness of the third main body portion 1130. In some embodiments, the third thickened portion 1131 is connected to the third main body portion 1130, and the wall thickness of the junction between the third thickened portion 1131 and the third main body portion 1130 can gradually increase so that the third thickened portion 1131 and the third main body portion 1130 have a smooth transition.

[0147] In some embodiments, the third thickened portion 1131 protrudes from the inner side of the third body portion 1130, that is, the portion of the third thickened portion 1131 protruding from the third body portion 1130 can be located inside the housing 11. In other embodiments, the third thickened portion 1131 protrudes from the outer side of the third body portion 1130, that is, the portion of the third thickened portion 1131 protruding from the third body portion 1130 can be located outside the housing 11. In other embodiments, the third thickened portion 1131 can protrude from both the outer side and the inner side of the third body portion 1130, that is, a portion of the third thickened portion 1131 protruding from the third body portion 1130 can be located outside the housing 11, and a portion can be located inside the housing 11.

[0148] In some embodiments, the third body portion 1130 may be a structure with uniform wall thickness. In other embodiments, the wall thickness of the third body portion 1130 may be unevenly distributed, and may be a structure with unequal wall thickness.

[0149] According to some embodiments of the present application, the maximum thickness of the second thickened portion 1121 is greater than the maximum thickness of the third thickened portion 1131 .

[0150] “The maximum thickness of the second thickened portion 1121 is greater than the maximum thickness of the third thickened portion 1131” can be understood as that the maximum thickness of the thickened portion of the corner area 112 is greater than the maximum thickness of the thickened portion of the second wall 113 , and can also be understood as that the strength of the second thickened portion 1121 is greater than the strength of the third thickened portion 1131 .

[0151] In some embodiments, the minimum thickness of the second thickened portion 1121 may be greater than the maximum thickness of the third thickened portion 1131. In other embodiments, the minimum thickness of the second thickened portion 1121 may be less than or equal to the maximum thickness of the third thickened portion 1131. In other embodiments, the minimum thickness of the second thickened portion 1121 may be less than or equal to the minimum thickness of the third thickened portion 1131.

[0152] In the above scheme, by setting the maximum thickness of the second thickened portion 1121 to be greater than the maximum thickness of the third thickened portion 1131, the strength of the portion of the corner area 112 corresponding to the opening 11a can be effectively improved. On the one hand, the overall thickness of the shell 11 can be effectively increased to reduce the risk of the shell 11 being cracked due to impact. On the other hand, the problem of stress concentration in the corner area 112 during the manufacturing process of the shell 11 causing cracking of the corner area 112 can be effectively improved, so that the battery cell 10 has higher reliability.

[0153] In other embodiments, the maximum thickness of the second thickened portion 1121 may be less than the maximum thickness of the third thickened portion 1131 ; in other embodiments, the maximum thickness of the second thickened portion 1121 may be less than the minimum thickness of the third thickened portion 1131 .

[0154] According to some embodiments of this application, see Figure 7 and Fig. 9 , the maximum thickness of the second thickened portion 1121 is T1, the thickness of the second main body portion 1120 is T2, the maximum thickness of the third thickened portion 1131 is t3, and the thickness of the third main body portion 1130 is t4, satisfying, E≥G, E=(T1-T2) / T2, G=(t3-t4) / t4.

[0155] In some embodiments, the corner area 112 of the shell 11 can be regarded as a part that is locally thickened with the second main body portion 1120 as a reference to form the second thickened portion 1121, T1-T2 is the difference between the maximum thickness of the second thickened portion 1121 and the thickness of the second main body portion 1120, and E is the difference between the maximum thickness of the second thickened portion 1121 and the thickness of the second main body portion 1120 divided by the thickness of the second main body portion 1120, that is, E can be regarded as the degree of thickening of the second thickened portion 1121 compared with the second main body portion 1120.

[0156] In some embodiments, the second wall 113 of the shell 11 can be regarded as a part that is locally thickened based on the third main body portion 1130 to form a third thickened portion 1131, t3-t4 is the difference between the maximum thickness of the third thickened portion 1131 and the thickness of the third main body portion 1130, G is the difference between the maximum thickness of the third thickened portion 1131 and the thickness of the third main body portion 1130 divided by the thickness of the third main body portion 1130, that is, G can be regarded as the degree of thickening of the third thickened portion 1131 compared with the third main body portion 1130.

[0157] “E≥G” can be understood as that the degree of thickening of the second thickened portion 1121 compared to the second main body portion 1120 is greater than or equal to the degree of thickening of the third thickened portion 1131 compared to the third main body portion 1130 .

[0158] In the above scheme, by limiting the degree E of thickening of the second thickened portion 1121 compared with the second main body portion 1120 to be no less than the degree G of thickening of the third thickened portion 1131 compared with the third main body portion 1130, the problem of stress concentration at the corner portion corresponding to the opening 11a during the manufacturing process of the shell 11 due to the provision of the third thickened portion 1131, resulting in cracking of the corner area 112, can be effectively improved, so that the battery cell 10 has higher reliability.

[0159] In other embodiments, the degree of thickening of the second thickened portion 1121 compared to the second main body portion 1120 is less than the degree of thickening of the third thickened portion 1131 compared to the third main body portion 1130 .

[0160] According to some embodiments of this application, see Figure 4 , along the first direction z, the distance from the end of the third thickened portion 1131 away from the opening 11 a to the opening 11 a is L3, satisfying 0<L3≤20 mm.

[0161] In some embodiments, the value of L3 can be a value greater than 0 and less than or equal to 20 mm. For example, the value of L3 can be 1 mm, 2 mm, 3 mm, 4 mm...15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm or any value between two adjacent values, or any value between 0 mm and 1 mm.

[0162] In some embodiments, the first direction z can be regarded as the up and down direction, and "the distance from the end of the third thickened portion 1131 away from the opening 11a to the opening 11a is L3" can be understood as, the third main body portion 1130 is L3 below the opening, and the third thickened portion 1131 is above the third main body portion 1130, or it can be understood that along the first direction z, the portion away from the opening 11a can define a dividing line, the third thickened portion 1131 is above the dividing line, and the third main body portion 1130 is below the dividing line.

[0163] In the above scheme, along the first direction z, by setting the third thickened portion 1131 in the area of ​​the second wall 113 within 20 mm below the opening 11a, the strength of the portion of the second wall 113 corresponding to the opening 11a can be effectively improved, and the risk of the second wall 113 being easily cracked by impact can be reduced, so that the battery cell 10 has higher reliability.

[0164] In some embodiments, the second wall 113 is a structure with uniform wall thickness.

[0165] “The second wall 113 is a structure of uniform wall thickness” can be understood as, along the first direction z, the wall thickness of any part of the second wall 113 is equal, and can also be understood as, the present application provides a battery cell 10, the first wall 110 and the corner area 112 of the battery cell 10 are partially provided with thickened parts, while the second wall 113 is not provided with thickened parts; or it can be understood as, the present application provides a battery cell 10, the first wall 110 and the corner area 112 of the battery cell 10 are partially provided with thickened parts, and the second wall 113 is thickened as a whole.

[0166] In the above scheme, under the condition that the first thickened portion 1101 is set on the first wall 110 and the second thickened portion 1121 is set in the corner area 112, the second wall 113 is set to a uniform wall thickness structure. On the one hand, it can ensure the strength of the shell 11 and reduce the risk of cracking of the shell 11. On the other hand, it can effectively control the weight of the shell 11 and reduce the influence of the thickening of the wall on the weight energy density of the battery cell 10.

[0167] According to some embodiments of this application, please combine Figure 4 and Fig.12 , Fig.12 for Figure 4 Enlarged view of L in the middle.

[0168] The battery cell 10 further includes an end cap 14, which closes the opening 11a. The third thickened portion 1131 includes a first section 1131a and a second section 1131b connected to each other, the first section 1131a, the second section 1131b and the third body portion 1130 (please refer to Fig. 9The maximum thickness of the second section 1131b is greater than the thickness of the third main body portion 1130, the maximum thickness of the second section 1131b is greater than the maximum thickness of the first section 1131a, and the end cover 14 is connected to the first section 1131a.

[0169] In some embodiments, along the first direction z, the third thickened portion 1131 may include a multi-segment structure. For example, along the first direction z, the third thickened portion 1131 includes a first segment 1131a and a second segment 1131b connected to each other, and the first segment 1131a is connected to the end cover 14. The connection method between the first segment 1131a and the end cover 14 may include welding. The second segment 1131b is connected to the third body portion 1130. The maximum thickness of the second segment 1131b may be the maximum thickness of the third thickened portion 1131, that is, the maximum thickness of the second wall 113.

[0170] In some embodiments, the maximum thickness of the first segment 1131a may be less than the maximum thickness of the second segment 1131b, and the maximum thickness of the first segment 1131a may be greater than, equal to, or less than the thickness of the third body portion 1130. Alternatively, the minimum thickness of the first segment 1131a may be greater than, equal to, or less than the thickness of the third body portion 1130.

[0171] In the above solution, by setting the thickness of the second section 1131b of the third thickened portion 1131 to be greater than the thickness of the third main body portion 1130, the strength of the second wall 113 can be effectively improved, and the risk of the second wall 113 being cracked by impact can be reduced, so that the battery cell 10 has higher reliability.

[0172] According to some embodiments of the present application, Figure 4 and Fig.12 A first step surface 1131c is formed between the second section 1131b and the first section 1131a, and the end cover 14 overlaps the first step surface 1131c.

[0173] In some embodiments, the maximum thickness of the second section 1131b is greater than the maximum thickness of the first section 1131a, so a first step surface 1131c is formed between the second section 1131b and the first section 1131a. In some embodiments, the first step surface 1131c can be inclined or perpendicular to the first direction z. The first step surface 1131c being inclined to the first direction z can be understood as forming an angle between the first step surface 1131c and the first direction z, and the angle is not 90°. “The end cover 14 overlaps the first step surface 1131c” can be understood as the first step surface 1131c can support the end cover 14, and when the end cover 14 is assembled, the first step surface 1131c can play a role in positioning the end cover 14.

[0174] In the above scheme, the first step surface 1131c formed between the second section 1131b and the first section 1131a can enable the end cover 14 to overlap the first step surface 1131c, thereby facilitating the positioning and assembly of the end cover 14; at the same time, the first step surface 1131c supports the end cover 14, reducing the risk of collapse of the end cover 14, thereby making the battery cell 10 have higher reliability.

[0175] According to some embodiments of the present application, the battery cell 10 further includes an end cover 14, which closes the opening 11a. The second thickened portion 1121 includes a third segment 1121a and a fourth segment 1121b connected to each other, the third segment 1121a, the fourth segment 1121b and the second body portion 1120 are sequentially distributed along the first direction z, the maximum thickness of the fourth segment 1121b is greater than the thickness of the second body portion 1120, the maximum thickness of the fourth segment 1121b is greater than the maximum thickness of the third segment 1121a, and the end cover 14 is connected to the third segment 1121a.

[0176] In some embodiments, along the first direction z, the second thickened portion 1121 may include a multi-segment structure. For example, along the first direction z, the second thickened portion 1121 includes a third segment 1121a and a fourth segment 1121b connected to each other, and the third segment 1121a is connected to the end cover 14. The connection method between the third segment 1121a and the end cover 14 may include welding. The fourth segment 1121b is connected to the second body portion 1120. The maximum thickness of the fourth segment 1121b may be the maximum thickness of the second thickened portion 1121, that is, the maximum thickness of the corner area 112.

[0177] In some embodiments, the maximum thickness of the third segment 1121a may be less than the maximum thickness of the fourth segment 1121b, and the maximum thickness of the third segment 1121a may be greater than, equal to, or less than the thickness of the second body portion 1120. Alternatively, the minimum thickness of the third segment 1121a may be greater than, equal to, or less than the thickness of the second body portion 1120.

[0178] In the above scheme, by setting the thickness of the fourth section 1121b of the second thickened portion 1121 to be greater than the thickness of the second main body portion 1120, the strength of the corner area can be effectively improved, and the risk of cracking in the corner area due to impact or stress concentration during demolding can be reduced, so that the battery cell 10 has higher reliability.

[0179] According to some embodiments of the present application, a second step surface 1121c is formed between the fourth section 1121b and the third section 1121c, and the end cover 14 overlaps the second step surface 1121c.

[0180] In some embodiments, the maximum thickness of the fourth section 1121b is greater than the maximum thickness of the third section 1121c, so a second step surface 1121c is formed between the fourth section 1121b and the third section 1121c. In some embodiments, the second step surface 1121c may be inclined or perpendicular to the first direction z. The second step surface 1121c being inclined to the first direction z can be understood as an angle formed between the second step surface 1121c and the first direction z, and the angle is not 90°.

[0181] “The end cover 14 overlaps the second step surface 1121c” can be understood as that the second step surface 1121c can support the end cover 14 and when the end cover 14 is assembled, the second step surface 1121c can position the end cover 14.

[0182] In the above scheme, the second step surface 1121c formed between the fourth section 1121b and the third section 1121c can enable the end cover 14 to overlap the second step surface 1121c, thereby facilitating the positioning and assembly of the end cover 14; at the same time, the second step surface 1121c supports the end cover 14, which can reduce the risk of collapse of the end cover 14, thereby making the battery cell 10 have higher reliability.

[0183] According to some embodiments of this application, see Fig.13 , Fig.13 Schematic diagram of end caps and corner areas in some embodiments of the present application.

[0184] The battery cell 10 also includes an end cover 14, which is welded to the second thickened portion 1121 to form a fusion zone 114. The average grain size of the second thickened portion 1121 other than the fusion zone 114 is greater than the average grain size of the second main body portion 1120, and the average grain size is the average grain size of the grains in the first direction z.

[0185] The fusion zone 114 is a zone formed by welding the second thickened portion 1121 and the end cover 14 . In some embodiments, the fusion zone 114 may be referred to as a welding zone or a weld mark.

[0186] “The portion of the second thickened portion 1121 other than the welding zone 114 ” may be understood as the portion of the second thickened portion that is not connected to the end cover 14 , that is, the portion of the second thickened portion 1121 that is not the welding zone 114 .

[0187] In some embodiments, the test method for average grain size refers to the following standards: GB / T 6394-2017 "Method for Determination of Average Grain Size of Metals" and GB / T 13298-2017 "Method for Determination of Grain Size of Metallic Materials by Electron Rear-view Microscope".

[0188] In the above scheme, by limiting the average grain size of the second thickened portion 1121 except the welding zone 114 to be larger than the average grain size of the second main body portion 1120, it is beneficial to enhance the strength of the second thickened portion 1121, so that the corner zone 112 has a higher strength, and reduces the risk of the corner zone 112 being cracked near the welding zone 114 due to impact and the risk of the corner zone 112 being cracked due to stress concentration during demolding, so that the battery cell 10 has a higher reliability.

[0189] In other embodiments, the end cap 14 is welded to the first thickened portion 1101 to form a fusion zone, and the average grain size of the first thickened portion 1101 other than the fusion zone is greater than the average grain size of the first body portion 1100, and the average grain size is the average grain size of the grains in the first direction z. In other embodiments, the end cap 14 is welded to the third thickened portion 1131 to form a fusion zone, and the average grain size of the third thickened portion 1131 other than the fusion zone is greater than the average grain size of the third body portion 1130, and the average grain size is the average grain size of the grains in the first direction z.

[0190] According to some embodiments of the present application, in a cross section of the corner area 112 parallel to the first direction z, the number of grains in a portion of the second thickened portion 1121 below the fusion zone 114 is greater than or equal to 15 in the width direction of the cross section.

[0191] In some embodiments, the “width direction of the cross section” may be the thickness direction of the corner region 112 .

[0192] In some embodiments, "the portion of the second thickened portion 1121 located below the welding zone 114, in the width direction of the cross-section, has a grain number greater than or equal to 15" can be understood as the portion of the second thickened portion 1121 located between the welding zone 114 and the second main body portion 1120, and the number of grains in the thickness direction of the corner zone 112 can be 15, 16, 17 or more.

[0193] In the above solution, in the width direction of the cross section, the number of grains is greater than or equal to 15, which is beneficial to enhancing the strength of the second thickened portion 1121 and improving the reliability of the battery 100.

[0194] In other embodiments, on a cross section of the first wall 110 parallel to the first direction z, the portion of the first thickened portion 1101 below the fusion zone 114, in the width direction of the cross section, has a number of grains greater than or equal to 15. In other embodiments, on a cross section of the second wall 113 parallel to the first direction z, the portion of the third thickened portion 1131 below the fusion zone 114, in the width direction of the cross section, has a number of grains greater than or equal to 15.

[0195] According to some embodiments of the present application, an average grain size of a portion of the second thickened portion 1121 other than the fusion zone 114 is in a range of 70 micrometers to 1200 micrometers.

[0196] And / or, in some embodiments, the average grain size of the second body portion 1120 is in the range of 30 micrometers to 1000 micrometers. And / or, in some embodiments, the maximum wall thickness of the end cap 14 is in the range of 0.25 mm to 3 mm.

[0197] In some embodiments, the average grain size of the second thickened portion 1121 excluding the fusion zone 114 may be, but is not limited to, 70 μm, 80 μm, 90 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm, 1100 μm, 1200 μm, etc., or any value between adjacent values.

[0198] In some embodiments, the average grain size of the second main body 1120 may be but is not limited to 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 200μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, 900μm, 1000μm, etc., or any value between adjacent values.

[0199] In some embodiments, the test scheme for average grain size can refer to: GB / T 6394-2002 "Method for Determination of Grain Size of Metallic Materials" and GB / T 13298-2017 "Method for Determination of Grain Size of Metallic Materials by Electron Rear-view Microscope".

[0200] In some embodiments, the maximum wall thickness of the end cap 14 can be but is not limited to 0.25 mm, 0.35 mm, 0.45 mm, 0.55 mm, 0.65 mm, 0.75 mm, 0.85 mm ... 2.75 mm, 2.85 mm, 2.95 mm, 3 mm, etc., or any value between adjacent values.

[0201] In the above solution, the average grain size of the second thickened portion 1121 and / or the average grain size of the second main body portion 1120 satisfies the above relationship, which is beneficial to enhancing the strength of the second thickened portion 1121 and making the battery cell 10 have higher reliability.

[0202] According to some embodiments of the present application, the present application also provides a battery 100 , and the battery 100 includes the battery cell 10 described above.

[0203] In some embodiments, the battery 100 includes a battery cell 10 and a box 20, wherein the battery cell 10 is contained in the box 20. The box 20 is used to provide a storage space for the battery cell 10. In the battery 100, there may be one or more battery cells 10, and each battery cell 10 may be fixed to the box 20 by a connector (such as a bolt), or each battery cell 10 may be fixed to the box 20 by bonding.

[0204] According to some embodiments of the present application, the present application further provides an energy storage device, which includes the battery cell 10 described above.

[0205] The energy storage device may include an energy storage cabinet, which includes a cabinet body and one or more battery cells 10 or one or more batteries 100 disposed in the cabinet body. The cabinet body may include a cabinet body and a cabinet door, wherein the one or more battery cells 10 are disposed in the cabinet body, and the cabinet door closes an opening 11a of the cabinet body so that the one or more battery cells 10 are in a closed space, thereby reducing the interference effect of external substances on the battery cells 10.

[0206] According to some embodiments of the present application, the present application further provides an electrical device, wherein the energy storage device includes the battery cell 10 described above.

[0207] In some embodiments, the electrical device may be a vehicle. A controller, a motor and a battery cell 10 may be arranged inside the vehicle, and the controller is used to control the battery cell 10 to supply power to the motor.

[0208] According to some embodiments of this application, see Figure 4-Figure 11 . A battery cell 10 is provided, and the battery cell 10 includes a shell 11 and an end cover. Along a first direction z, the shell 11 has an opening 11a, and an electrode assembly 12 is arranged inside the shell 11. The end cover is connected to the shell 11 to close the opening 11a, so that the electrode assembly 12 is located in a closed space. Along a second direction x, the shell 11 includes two first walls 110 arranged opposite to each other, and along a third direction y, the shell 11 includes two second walls 113 arranged opposite to each other, and the second direction x, the third direction y and the first direction z are perpendicular to each other. Adjacent first walls 110 and second walls 113 are connected by corresponding corner areas 112, and the first wall 110, the second wall 113 and the corner area 112 together enclose the opening 11a.

[0209] The first wall 110 has a first main body portion 1100 and a first thickened portion 1101 arranged along a first direction z, the first main body portion 1100 is farther from the opening 11a than the first thickened portion 1101, and the maximum thickness of the first thickened portion 1101 is greater than the thickness of the first main body portion 1100. The second wall 113 has a third main body portion 1130 and a third thickened portion 1131 arranged along the first direction z, the third main body portion 1130 is farther from the opening 11a than the third thickened portion 1131, and the maximum thickness of the third thickened portion 1131 is greater than the thickness of the third main body portion 1130.

[0210] The corner area 112 has a second main body portion 1120 and a second thickened portion 1121 arranged along the first direction z. The second main body portion 1120 is farther away from the opening 11a than the second thickened portion 1121 . The maximum thickness of the second thickened portion 1121 is greater than the thickness of the second main body portion 1120 .

[0211] In the above scheme, by providing the first thickened portion 1101 on the first wall 110 and the third thickened portion 1131 on the second wall 113, the problem that the shell 11 has a low-strength heat-affected zone formed by welding, which causes the shell 11 to crack due to insufficient strength when impacted, can be improved, so that the battery 100 has higher reliability. At the same time, by providing the second thickened portion 1121 in the corner area 112, the strength of the corner area 112 corresponding to the opening 11a can be improved, and the stress concentration caused by the first thickened portion 1101 and the second thickened portion 1121 during demolding, which causes the corner area 112 to crack, can be improved, so that the battery cell 10 has higher reliability.

[0212] In some embodiments, the thickness of the second thickened portion 1121 is T1, and the thickness of the second body portion 1120 is T2, satisfying 0<E<30%, E=(T1-T2) / T2. In other embodiments, 0<E≤16.7%.

[0213] For example, based on the battery cell 10 provided above, different E values ​​and demoulding feasibility are tested and verified. The test verification results can be seen in the following table:

[0214] plan T2(mm) T1(mm) E Manufacturability Verification Results 1 0.6 0.65 8.3％ OK 2 0.6 0.7 16.7％ OK 3 0.6 0.75 25％ OK 4 0.6 0.78 30％ Shell 11 convex, NG 5 0.6 0.8 33.3％ Shell 11 convex, NG 6 0.6 0.81 35.0％ Shell 11 convex, NG

[0215] It can be seen from the above table that the degree of thickening of the thickened part of the corner area 112 can be within a certain range. For example, the thickness of the second thickened portion 1121 is T1, and the thickness of the second body portion 1120 is T2, satisfying 0<E<30%.

[0216] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: A shell having an opening formed at an end portion along a first direction; along the circumference of the opening, the shell comprises a first wall, a corner area and a second wall connected in sequence; The first wall comprises a first main body portion and a first thickened portion arranged along the first direction, the first main body portion is farther away from the opening than the first thickened portion, and the maximum thickness of the first thickened portion is greater than the thickness of the first main body portion; The corner area has a second main body portion and a second thickened portion arranged along the first direction, the second main body portion is farther away from the opening than the second thickened portion, and the maximum thickness of the second thickened portion is greater than the thickness of the second main body portion.

2. The battery cell according to claim 1, characterized in that: The maximum thickness of the second thickened portion is greater than the maximum thickness of the first thickened portion.

3. The battery cell according to claim 1, characterized in that: The maximum thickness of the second thickened portion is T1, the thickness of the second main body portion is T2, the maximum thickness of the first thickened portion is t1, and the thickness of the first main body portion is t2, satisfying E≥F, E=(T1-T2) / T2, and F=(t1-t2) / t2.

4. The battery cell according to claim 1, characterized in that: The maximum thickness of the second thickened portion is T1, and the thickness of the second main body portion is T2, satisfying 0<E<30%, and E=(T1-T2) / T2.

5. The battery cell according to claim 4, characterized in that: Satisfies, 0<E≤16.7%.

6. The battery cell according to claim 1, characterized in that: Along the first direction, a distance from one end of the second thickened portion away from the opening to the opening is L1, satisfying 0<L1≤20 mm.

7. The battery cell according to claim 1, characterized in that: Along the first direction, a distance from one end of the first thickened portion away from the opening to the opening is L2, satisfying 0<L2≤20 mm.

8. The battery cell according to claim 1, characterized in that: An area of ​​an outer surface of the first wall is greater than an area of ​​an outer surface of the second wall.

9. The battery cell according to claim 1, characterized in that: Along the second direction, the shell includes two first walls arranged opposite to each other, and along the third direction, the shell includes two second walls arranged opposite to each other, and the second direction, the third direction and the first direction are perpendicular to each other; The adjacent first walls and second walls are connected via the corresponding corner areas, and the first walls, the second walls and the corner areas together form the opening.

10. The battery cell according to any one of claims 1 to 9, characterized in that: The second wall has a third main body portion and a third thickened portion arranged along the first direction, the third main body portion is farther away from the opening than the third thickened portion, and the maximum thickness of the third thickened portion is greater than the thickness of the third main body portion.

11. The battery cell according to claim 10, characterized in that: The maximum thickness of the second thickened portion is greater than the maximum thickness of the third thickened portion.

12. The battery cell according to claim 10, characterized in that: The maximum thickness of the second thickened portion is T1, the thickness of the second main body portion is T2, the maximum thickness of the third thickened portion is t3, and the thickness of the third main body portion is t4, satisfying E≥G, E=(T1-T2) / T2, G=(t3-t4) / t4.

13. The battery cell according to claim 10, characterized in that: Along the first direction, a distance from one end of the third thickened portion away from the opening to the opening is L3, satisfying 0<L3≤20mm.

14. The battery cell according to claim 10, characterized in that: The battery cell further includes an end cover, the end cover closing the opening; The third thickened portion includes a first section and a second section connected to each other, the first section, the second section and the third main body portion are distributed in sequence along the first direction, the maximum thickness of the second section is greater than the thickness of the third main body portion, the maximum thickness of the second section is greater than the maximum thickness of the first section, and the end cover is connected to the first section.

15. The battery cell according to claim 14, characterized in that: A first step surface is formed between the second section and the first section, and the end cover is overlapped on the first step surface.

16. The battery cell according to any one of claims 1 to 9, characterized in that: The battery cell further includes an end cover, the end cover closing the opening; The second thickened portion includes a third section and a fourth section that are connected to each other. The third section, the fourth section and the second main body are distributed in sequence along the first direction. The maximum thickness of the fourth section is greater than the thickness of the second main body. The maximum thickness of the fourth section is greater than the maximum thickness of the third section. The end cover is connected to the third section.

17. The battery cell according to claim 16, characterized in that: A second step surface is formed between the fourth section and the third section, and the end cover is overlapped on the second step surface.

18. The battery cell according to any one of claims 1 to 9, characterized in that: The battery cell also includes an end cover, which is welded to the second thickened portion to form a fusion zone. The average grain size of the second thickened portion other than the fusion zone is greater than the average grain size of the second main body portion, and the average grain size is the average grain size of the grains in the first direction.

19. The battery cell according to claim 18, characterized in that: On a cross section of the corner region parallel to the first direction, in a portion of the second thickened portion below the fusion zone, the number of grains in the width direction of the cross section is greater than or equal to 15.

20. The battery cell according to claim 18, characterized in that: The average grain size of the second thickened portion other than the fusion zone is in the range of 70 μm to 1200 μm; and / or, the average grain size of the second body portion is in the range of 30 μm to 1000 μm; And / or, the maximum wall thickness of the end cover is 0.25 mm-3 mm.

21. A battery, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 20.

22. An energy storage device, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 20.

23. An electrical device, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 20.

Images