Battery cell, battery, electric device and energy storage apparatus

Abstract

Provided in the embodiments of the present application are a battery cell, a battery, an electric device and an energy storage apparatus. The battery cell comprises a casing and a pressure relief mechanism. The casing comprises a shell, wherein the shell comprises a side wall and a bottom wall, the side wall surrounding an edge of the bottom wall. The pressure relief mechanism is arranged on the bottom wall. The side wall comprises a thickened portion and a body portion, which are distributed in sequence in a first direction; the first direction is parallel to the direction of the thickness of the bottom wall; the body portion is away from the bottom wall relative to the thickened portion; the thickened portion is connected to the bottom wall; and the maximum thickness of the thickened portion is greater than that of the body portion. On the basis of the technical solution provided in the embodiments of the present application, the reliability of the battery cell can be improved.

Description

Battery cells, batteries, electrical equipment and energy storage devices CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Chinese patent application CN202420292353.2, filed on February 18, 2024, entitled “Battery Cell, Battery, Electrical Equipment and Energy Storage Device,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, an electrical device, and an energy storage device. Background Art

[0003] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the sustainable development of the automotive industry. For electric vehicles, battery technology is a key factor in their development.

[0004] During the manufacturing process of batteries, battery reliability is an issue that cannot be ignored. Therefore, how to improve battery reliability is a technical problem that needs to be solved urgently in battery technology. Summary of the Invention

[0005] The present application provides a battery cell, a battery, an electrical device and an energy storage device, which can improve the reliability of the battery cell.

[0006] This application is achieved through the following technical solutions:

[0007] In a first aspect, embodiments of the present application provide a battery cell comprising an outer shell and a pressure relief mechanism. The outer shell comprises a housing, the housing comprising side walls and a bottom wall, the side walls being disposed around the edges of the bottom wall. The pressure relief mechanism is disposed on the bottom wall. The side walls comprise a thickened portion and a main body portion sequentially distributed along a first direction, the first direction being parallel to the thickness direction of the bottom wall, the main body portion being spaced away from the bottom wall relative to the thickened portion, the thickened portion being connected to the bottom wall, and the maximum thickness of the thickened portion being greater than the thickness of the main body portion.

[0008] According to the battery cell of the embodiment of the present application, the maximum thickness of the thickened portion is greater than the thickness of the main body portion, the thickened portion is connected to the bottom wall, and the connection between the side wall and the bottom wall is thickened to improve the strength of the connection between the side wall and the bottom wall, improve the tensile strength of the shell, reduce the risk of premature pressure relief and leakage of the pressure relief mechanism, and improve the reliability of the battery cell.

[0009] According to some embodiments of the present application, along the first direction, the size of the thickened portion is h, and the size of the side wall is H, satisfying 0.5 mm ≤ h ≤ 0.5*H.

[0010] In the above scheme, the size of the thickened portion in the first direction and the size of the side wall in the first direction satisfy the above relationship. On the one hand, when h≥0.5mm, the thickened portion has higher strength. On the other hand, when h≤0.5*H, the risk of interference between the thickened portion and other components is reduced, so that the battery cell has a higher energy density.

[0011] According to some embodiments of the present application, 1 mm ≤ h ≤ 2 mm.

[0012] In the above scheme, compared with h<1mm, when h≥1mm, the strength of the thickened portion can be improved; compared with h>2mm, when h≤2mm, the thickened portion occupies less space in the first direction, further reducing the risk of interference between the thickened portion and other components, so that the battery cell has a higher energy density.

[0013] According to some embodiments of the present application, the maximum thickness of the thickened portion is W1, and the thickness of the main body portion is W2, satisfying 0.05 mm ≤ W1 - W2 ≤ W2.

[0014] In the above scheme, the difference between the maximum thickness of the thickened portion and the thickness of the main body satisfies the above relationship. On the one hand, when W1-W2≥0.05mm, the thickened portion has a thicker thickness and the strength of the thickened portion is higher. On the other hand, when W1-W2≤W2, the thickened portion occupies less space in the thickness direction of the side wall, and the risk of interference between the thickened portion and other components is smaller.

[0015] According to some embodiments of the present application, 0.2 mm ≤ W1 - W2 ≤ 0.8*W2.

[0016] In the above scheme, compared with W1-W2<0.2mm, when W1-W2≥0.2mm, the thickened portion is further made to have a thicker thickness and higher strength; compared with W1-W2>0.8*W2, when W1-W2≤0.8*W2, the thickened portion occupies less space in the thickness direction of the side wall and the risk of interference with other components is smaller.

[0017] According to some embodiments of the present application, 0.25 mm ≤ W1 ≤ 2.4 mm.

[0018] In the above scheme, the maximum thickness of the thickened portion satisfies the above relationship. On the one hand, when W1 ≥ 0.25 mm, the thickened portion has a thicker thickness and higher strength. On the other hand, when W1 ≤ 2.4 mm, the thickened portion occupies less space in the thickness direction of the side wall, and the risk of interference between the thickened portion and other components is smaller.

[0019] According to some embodiments of the present application, 0.8 mm ≤ W1 ≤ 1.8 mm.

[0020] In the above scheme, compared with W1<0.8mm, when W1≥0.8mm, the thickened portion is further made thicker and the strength of the thickened portion is higher; compared with W1>1.8mm, when W1≤1.8mm, the thickened portion occupies less space in the thickness direction of the side wall and the risk of interference with other components is smaller.

[0021] According to some embodiments of the present application, the maximum thickness of the thickened portion is smaller than the thickness of the bottom wall.

[0022] In the above solution, the thickness of the bottom wall is greater than the maximum thickness of the thickened portion, and the bottom wall has a higher strength to reduce the risk of premature damage to the pressure relief mechanism.

[0023] According to some embodiments of the present application, along the circumference of the side wall, the thickness of the thickened portion at any position is greater than the thickness of the main body portion.

[0024] In the above solution, the thickness of the thickened portion at any position along the circumference of the side wall is greater than the thickness of the main body, so that the thickened portion has higher strength in the circumference of the side wall, thereby improving the tensile strength of the shell.

[0025] According to some embodiments of the present application, the thickened portion includes multiple thickened areas, which are arranged at circumferential intervals along the side wall; the thickened portion also includes a transition area connecting any two adjacent thickened areas, the thickness of the thickened area is greater than the thickness of the main body, and the thickness of the thickened area is greater than the thickness of the transition area.

[0026] In the above scheme, multiple thickened areas are arranged at circumferential intervals along the side wall, which on the one hand facilitates the extension of the material and facilitates the stamping and forming of the shell, and on the other hand reduces the difficulty of demolding the shell; two adjacent thickened areas are connected by a transition area, and the thickness of the thickened area is greater than the thickness of the transition area, which facilitates the processing and forming of the thickened area.

[0027] According to some embodiments of the present application, the side wall includes two first side walls arranged opposite to each other in a second direction, and two second side walls arranged opposite to each other in a third direction; the first side wall includes a first thickened portion and a first main body portion, and along the first direction, the first thickened portion is connected between the first main body portion and the bottom wall; the second side wall includes a second thickened portion and a second main body portion, and along the first direction, the second thickened portion is connected between the second main body portion and the bottom wall; the two first thickened portions and the two second thickened portions are constructed as thickened portions, and the two first main body portions and the two second main body portions are constructed as main body portions; wherein the maximum thickness of the first thickened portion is greater than the thickness of the main body portion, and the maximum thickness of the second thickened portion is greater than the thickness of the main body portion.

[0028] In the above scheme, the two ends of the first side wall are respectively connected to the two second side walls, and the two first side walls and the two second side walls form a space for accommodating the electrode assembly. The maximum thickness of the first thickened part is greater than the thickness of the main body, and the maximum thickness of the second thickened part is greater than the thickness of the main body. Both the first thickened part and the second thickened part have high strength, so that the shell has a high tensile strength.

[0029] According to some embodiments of the present application, the area of ​​the outer surface of the first side wall is larger than the area of ​​the outer surface of the second side wall, the maximum thickness of the first thickened portion is larger than the thickness of the first main body portion, and the maximum thickness of the second thickened portion is larger than the thickness of the second main body portion.

[0030] In the above scheme, the first side wall can be the large surface of the shell, the second side wall can be the narrow surface of the shell, the maximum thickness of the first thickened part is greater than the thickness of the first main body part, and the maximum thickness of the second thickened part is greater than the thickness of the second main body part, so that the shell has a higher tensile resistance.

[0031] In a second aspect, an embodiment of the present application further provides a battery, which includes a battery cell provided in any of the above embodiments.

[0032] In a third aspect, an embodiment of the present application further provides an electrical device, which includes a battery cell or a battery as provided in any of the above embodiments, and the battery cell or the battery is used to provide electrical energy.

[0033] In a fourth aspect, an embodiment of the present application further provides an energy storage device, which includes a battery cell or a battery as provided in any of the above embodiments.

[0034] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0036] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0037] FIG2 is an exploded schematic diagram of a battery provided in some embodiments of the present application;

[0038] FIG3 is an exploded schematic diagram of a battery cell provided in some embodiments of the present application;

[0039] FIG4 is a schematic diagram of the assembly of a bottom wall and a pressure relief mechanism provided in some embodiments of the present application;

[0040] FIG5 is a schematic structural diagram of side walls and bottom walls provided in some embodiments of the present application;

[0041] FIG6 is a partial enlarged view of point A in FIG5 ;

[0042] FIG7 is a schematic diagram of multiple thickened areas provided in some embodiments of the present application;

[0043] FIG8 is an exploded schematic diagram of a battery cell provided in some other embodiments of the present application;

[0044] FIG9 is a schematic structural diagram of side walls and bottom walls provided in other embodiments of the present application;

[0045] FIG10 is a schematic structural diagram of a side wall provided in some embodiments of the present application;

[0046] FIG11 is a partial enlarged view of point B in FIG10 ;

[0047] In the drawings, the drawings are not drawn to scale.

[0048] Marking instructions: 100-battery; 10-case; 11-first sub-case; 12-second sub-case; 20-battery cell; 21-shell; 211-shell; 212-end cover; 22-electrode assembly; 23-electrode terminal; 24-pressure relief mechanism; 25-side wall; 25a-first side wall; 25b-second side wall; 251-thickening portion; 251a-thickening area; 251b-transition area; 251c-first thickening portion; 251d-second thickening portion; 252-main body; 252a-first main body; 252b-second main body; 2521-first surface; 2522-second surface; 26-bottom wall; 27-top wall; 200-controller; 300-motor; 1000-vehicle; P-circumferential direction of side wall; X-first direction; Y-second direction; Z-third direction. DETAILED DESCRIPTION

[0049] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0050] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0051] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0052] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0053] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0054] The term "multiple" in this application 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).

[0055] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0056] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0057] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0058] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0059] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0060] The battery cells may be, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, and the like.

[0061] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0062] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0063] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0064] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0065] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used.

[0066] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0067] As an example, the negative electrode current collector may be a metal foil or a composite current collector. For example, the metal foil may be silver-plated aluminum, silver-plated stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium.

[0068] In some embodiments, the negative electrode current collector has two opposite surfaces in its thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0069] As an example, the negative electrode active material may be a negative electrode active material for a battery that is well known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0070] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0071] As an example, the primary material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component positioned between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0072] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0073] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0074] In some embodiments, the electrode assembly is a laminate structure.

[0075] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, or a composite metal housing (e.g., a copper-aluminum composite housing).

[0076] In some embodiments, the housing includes an end cap and a shell. The shell has an opening, and the end cap closes the opening to form a sealed space for accommodating the electrode assembly, electrolyte, and other substances. The shell may have one or more openings. One or more end caps may also be provided.

[0077] In some embodiments, the housing is provided with at least one electrode terminal, which is electrically connected to a tab of the electrode assembly. The electrode terminal may be directly connected to the tab or indirectly connected to the tab via an adapter. The electrode terminal may be provided on an end cap or on the housing.

[0078] In some embodiments, the housing is provided with an explosion-proof valve for releasing the internal pressure of the battery cell.

[0079] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell or a battery cell of other shapes. Prismatic battery cells include square-shell battery cells, blade-shaped battery cells, and polygonal prismatic batteries. Polygonal prismatic batteries are, for example, hexagonal prismatic batteries.

[0080] The development of battery technology must take into account multiple design factors at the same time, such as energy density, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery reliability must also be considered.

[0081] In some embodiments, the battery cell includes a housing and an electrode assembly, as well as other functional components (such as electrode terminals and a pressure relief mechanism). The electrode assembly is disposed in the housing, and the electrode terminals are disposed on the end caps of the housing. In order to separate the high-temperature gas discharged by the pressure relief mechanism from the electrical connection components when the battery cell thermal runaway occurs, the pressure relief mechanism is usually disposed on the shell of the housing. However, due to the limitation of the energy density of the battery cell, the thickness of the shell cannot be too thick, which makes the shell's resistance to pulling weaker. For example, when the pressure relief mechanism is disposed on the bottom wall, during the charge and discharge cycle of the battery cell, the shell is prone to expansion and deformation, pulling the bottom wall of the shell, thereby causing the pressure relief mechanism to release pressure prematurely in a non-working state and causing electrolyte leakage, making the reliability of the battery cell lower.

[0082] In view of this, an embodiment of the present application provides a technical solution, wherein a battery cell includes an outer shell and a pressure relief mechanism, wherein the outer shell includes a shell, the shell includes side walls and a bottom wall, and the pressure relief mechanism is arranged on the bottom wall. The side walls are arranged around the bottom wall, and the side walls include a thickened portion and a main body portion distributed in sequence along a first direction, the first direction being parallel to the thickness direction of the bottom wall, the main body portion is away from the bottom wall relative to the thickened portion, the thickened portion is connected to the bottom wall, and the maximum thickness of the thickened portion is greater than the thickness of the main body portion, thereby increasing the strength of the shell, improving the shell's resistance to pulling, reducing the risk of premature pressure relief and leakage of the pressure relief mechanism when not in operation, and improving the reliability of the battery cell.

[0083] In such a battery cell, since the thickened portion connects the bottom wall and the main body, the thickened portion is the part where the side wall and the bottom wall are connected, and the maximum thickness of the thickened portion is greater than the thickness of the main body, which is equivalent to the thickening treatment of the thickened portion, that is, the thickening treatment is performed at the connection between the side wall and the bottom wall, which can improve the strength of the connection between the side wall and the bottom wall, improve the tensile strength of the shell, and reduce the risk of premature pressure relief and leakage of the pressure relief mechanism, so that the battery cell has higher reliability.

[0084] The battery cells or batteries disclosed in the embodiments of the present application can be used, but are not limited to, in electrical equipment such as vehicles, ships, or aircraft. The battery cells or batteries disclosed in the present application can be used to form a power supply system for the electrical equipment.

[0085] The embodiments of the present application provide an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0086] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device in an embodiment of the present application.

[0087] Please refer to Figure 1, which is a schematic diagram of the structure of the vehicle provided in some embodiments of the present application. Vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can be used as an operating power source for the vehicle 1000, for the circuit system of the vehicle 1000, such as for the working power requirements during the startup, navigation and operation of the vehicle 1000.

[0088] The vehicle 1000 may further include a controller 200 and a motor 300 . The controller 200 is used to control the battery 100 to supply power to the motor 300 , for example, to meet the power requirements of the vehicle 1000 during startup, navigation, and driving.

[0089] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0090] Please refer to Figure 2, which is an exploded schematic diagram of a battery provided in some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20, with the battery cell 20 being housed within the housing 10. The housing 10 is used to provide a storage space for the battery cell 20, and the housing 10 can adopt a variety of structures. In some embodiments, the housing 10 can include a first sub-housing 11 and a second sub-housing 12, the first sub-housing 11 and the second sub-housing 12 covering each other, and the first sub-housing 11 and the second sub-housing 12 jointly defining a storage space for accommodating the battery cell 20. The second sub-housing 12 can be a hollow structure with one end open, and the first sub-housing 11 can be a plate-shaped structure, with the first sub-housing 11 covering the open side of the second sub-housing 12, so that the first sub-housing 11 and the second sub-housing 12 jointly define a storage space; the first sub-housing 11 and the second sub-housing 12 can also be hollow structures with one end open, with the open side of the first sub-housing 11 covering the open side of the second sub-housing 12.

[0091] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0092] The battery cell 20 may be a secondary battery or a primary battery; the battery cell 20 may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto.

[0093] Please refer to Figure 3, which is an exploded schematic diagram of a battery cell provided in some embodiments of the present application. As shown in Figure 3, a battery cell 20 includes a housing 21, an electrode assembly 22, and other functional components. Housing 21 includes a shell 211 and an end cap 212. Shell 211 has an opening, and end cap 212 closes the opening, isolating the internal environment of battery cell 20 from the external environment.

[0094] The housing 211 is a component used to cooperate with the end cap 212 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 22, electrolyte, and other components. The housing 211 and the end cap 212 can be independent components. The housing 211 can be of various shapes and sizes. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the electrode assembly 22. The housing 211 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0095] The end cap 212 refers to a component that covers the opening of the shell 211 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 212 can be adapted to the shape of the shell 211 to match the shell 211. Optionally, the end cap 212 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 212 is not easily deformed when squeezed or collided, so that the battery cell 20 can have a higher structural strength and the reliability can also be improved. Functional components such as electrode terminals 23 can be provided on the end cap 212. The electrode terminal can be used to electrically connect to the electrode assembly 22 for outputting or inputting electrical energy of the battery cell 20. The material of the end cap 212 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this. In some embodiments, an insulating structure may be provided inside the end cap 212 to isolate the electrical thickening components in the housing 211 from the end cap 212 to reduce the risk of short circuits. For example, the insulating structure may be made of plastic, rubber, or the like.

[0096] The electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 22 may be contained in the housing 211. The electrode assembly 22 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The separator is used to separate the positive electrode sheet and the negative electrode sheet to avoid internal short circuits between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a tab. The positive electrode tab and the negative electrode tab may be located together at one end of the main body or respectively at both ends of the main body.

[0097] Please refer to Figure 3 and further to Figures 4 to 6. Figure 4 is a schematic diagram of the assembly of a bottom wall and a pressure relief mechanism according to some embodiments of the present application. Figure 5 is a schematic diagram of the structure of the side wall and bottom wall according to some embodiments of the present application. Figure 6 is an enlarged partial view of point A in Figure 5. According to some embodiments of the present application, a battery cell 20 is provided. The battery cell 20 includes an outer shell 21 and a pressure relief mechanism 24. The outer shell 21 includes a shell 211, which includes side walls 25 and a bottom wall 26. The side walls 25 are disposed around the edges of the bottom wall 26. The pressure relief mechanism 24 is disposed on the bottom wall 26. The side wall 25 includes a thickened portion 251 and a main body 252, which are sequentially arranged along a first direction X. The first direction X is parallel to the thickness direction of the bottom wall 26. The main body 252 is spaced away from the bottom wall 26 relative to the thickened portion 251. The thickened portion 251 is connected to the bottom wall 26. The maximum thickness of the thickened portion 251 is greater than the thickness of the main body 252.

[0098] In the figure, the direction indicated by the letter X is the first direction.

[0099] In some embodiments, one end of the side wall 25 is connected to the bottom wall 26, and the other end of the side wall 25 forms an opening; the outer shell 21 also includes an end cover 212, which closes the opening and is connected to the side wall 25 to form a closed accommodating cavity with the shell 211, and the electrode assembly is accommodated in the accommodating cavity.

[0100] In some embodiments, the side wall 25 may also form an opening with the bottom wall 26. The housing 21 further includes an end cap 212, which is connected to the side wall 25 and the bottom wall 26 to close the opening.

[0101] The pressure relief mechanism 24 is provided on the bottom wall 26 and is used to release the internal pressure of the battery cell 20. The pressure relief mechanism 24 can be a pressure relief component, or the pressure relief mechanism 24 can also be provided in a notch on the bottom wall 26.

[0102] In some embodiments, the bottom wall 26 may be provided with a through hole, and the pressure relief mechanism 24 is disposed in the through hole and closes the through hole.

[0103] The thickened portion 251 and the main body portion 252 are distributed in sequence in the first direction X. The thickened portion 251 connects the bottom wall 26 and the main body portion 252 . The thickened portion 251 may be a portion of the side wall 25 connected to the bottom wall 26 .

[0104] In some embodiments, the thickened portion 251 may be a variable thickness structure, and the maximum thickness of the thickened portion 251 is the thickness at the maximum thickness position of the thickened portion 251. Alternatively, the thickened portion 251 may be a uniform thickness structure, and the maximum thickness of the thickened portion 251 is the thickness at any position of the thickened portion 251.

[0105] Optionally, the thickened portion 251 may be a thickening structure, and the thickness of the thickened portion 251 gradually decreases in a direction from the bottom wall 26 to the main body portion 252 .

[0106] In some embodiments, the housing 211 is integrally formed, for example, the housing 211 is stamped, or the housing 211 is cast. Optionally, the housing 211 is stamped to facilitate processing and manufacturing.

[0107] Referring to Figure 6 , the main body 252 has a first surface 2521 facing the interior of the battery cell 20 and a second surface 2522 facing away from the interior of the battery cell 20. The first surface 2521 and the second surface 2522 are disposed opposite each other in the thickness direction of the main body 252. In some embodiments, the thickened portion 251 may protrude from the first surface 2521. In some embodiments, the thickened portion 251 may protrude from the second surface 2522; alternatively, the thickened portion 251 may protrude from both the first surface 2521 and the second surface 2522.

[0108] In some embodiments, the thickness of the bottom wall 26 is greater than or equal to the maximum thickness of the thickened portion 251 , so that the bottom wall 26 has a higher strength.

[0109] According to the battery cell 20 of the embodiment of the present application, since the thickened portion 251 connects the bottom wall 26 and the main body portion 252, the thickened portion 251 is the portion where the side wall 25 is connected to the bottom wall 26, and the maximum thickness of the thickened portion 251 is greater than the thickness of the main body portion 252, which is equivalent to the thickened portion 251 being thickened, that is, the connection between the side wall 25 and the bottom wall 26 is thickened, which can improve the strength of the connection between the side wall 25 and the bottom wall 26, improve the tensile strength of the shell 211, and reduce the risk of premature pressure relief and leakage of the pressure relief mechanism 24, so that the battery cell 20 has higher reliability.

[0110] 5 and 6 , according to some embodiments of the present application, along the first direction X, the dimension of the thickened portion 251 is h, and the dimension of the sidewall 25 is H, satisfying 0.5 mm ≤ h ≤ 0.5*H.

[0111] Optionally, h can be but is not limited to 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 2 mm, 0.1*H, 0.2*H, 0.3*H, 0.4*H, 0.5*H, etc.

[0112] In the above scheme, the size of the thickened portion 251 in the first direction X and the size of the side wall 25 in the first direction X satisfy the above relationship (0.5mm≤h≤0.5*H). On the one hand, when h≥0.5mm, the thickened portion 251 has higher strength. On the other hand, when h≤0.5*H, the risk of interference between the thickened portion 251 and other components is reduced, so that the battery cell 20 has a higher energy density.

[0113] According to some embodiments of the present application, 1 mm ≤ h ≤ 2 mm.

[0114] Optionally, h can be, but is not limited to, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, etc.

[0115] In the above scheme, compared with h<1mm, when h≥1mm, the strength of the thickened portion 251 can be improved; compared with h>2mm, when h≤2mm, the thickened portion 251 occupies less space in the first direction X, further reducing the risk of interference between the thickened portion 251 and other components, so that the battery cell 20 has a higher energy density.

[0116] Referring to FIG. 6 , according to some embodiments of the present application, the maximum thickness of the thickened portion 251 is W1 , and the thickness of the main body portion 252 is W2 , satisfying 0.05 mm ≤ W1 - W2 ≤ W2 .

[0117] Optionally, W1-W2 may be but not limited to 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.15mm, etc., or, W1-W2 may be but not limited to 0.1*W2, 0.3*W2, 0.5*W2, 0.7*W2, 0.9*W2, W2, etc.

[0118] In the above scheme, the difference between the maximum thickness of the thickened portion 251 and the thickness of the main body portion 252 satisfies the above relationship. On the one hand, when W1-W2≥0.05mm, the thickened portion 251 has a thicker thickness and the strength of the thickened portion 251 is higher. On the other hand, when W1-W2≤W2, the thickened portion 251 occupies a smaller space in the thickness direction of the side wall 25, and the risk of interference between the thickened portion 251 and other components is smaller.

[0119] According to some embodiments of the present application, 0.2 mm ≤ W1 - W2 ≤ 0.8*W2.

[0120] Optionally, W1-W2 may be but not limited to 0.2 mm, 0.21 mm, 0.22 mm, 0.23 mm, 0.24 mm, 0.25 mm, 0.26 mm, etc., or W1-W2 may be but not limited to 0.2*W2, 0.4*W2, 0.6*W2, 0.8*W2, etc.

[0121] In the above scheme, compared with W1-W2<0.2mm, when W1-W2≥0.2mm, the thickened portion 251 is further made to have a thicker thickness, and the strength of the thickened portion 251 is higher; compared with W1-W2>0.8*W2, when W1-W2≤0.8*W2, the thickened portion 251 occupies a smaller space in the thickness direction of the side wall 25, and the risk of interference between the thickened portion 251 and other components is smaller.

[0122] According to some embodiments of the present application, 0.25 mm ≤ W1 ≤ 2.4 mm.

[0123] Optionally, W1 can be but is not limited to 0.25mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, etc.

[0124] In the above scheme, the maximum thickness of the thickened portion 251 satisfies the above relationship. On the one hand, when W1 ≥ 0.25 mm, the thickened portion 251 has a thicker thickness and the strength of the thickened portion 251 is higher. On the other hand, when W1 ≤ 2.4 mm, the thickened portion 251 occupies a smaller space in the thickness direction of the side wall 25, and the risk of interference between the thickened portion 251 and other components is smaller.

[0125] According to some embodiments of the present application, 0.8 mm ≤ W1 ≤ 1.8 mm.

[0126] Optionally, W1 can be but is not limited to 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.05mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.45mm, 1.5mm, 1.55mm, 1.6mm, 1.65mm, 1.7mm, 1.75mm, 1.8mm, etc.

[0127] In the above scheme, compared with W1<0.8mm, when W1≥0.8mm, the thickened portion 251 is further made thicker, and the strength of the thickened portion 251 is higher; compared with W1>1.8mm, when W1≤1.8mm, the thickened portion 251 occupies less space in the thickness direction of the side wall 25, and the risk of interference between the thickened portion 251 and other components is smaller.

[0128] According to some embodiments of the present application, 0.2 mm ≤ W2 ≤ 1.2 mm.

[0129] Optionally, 0.6mm≤W2≤1mm.

[0130] Optionally, W2 can be but is not limited to 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.05mm, 1.1mm, 1.15mm, 1.2mm, etc.

[0131] According to some embodiments of the present application, the maximum thickness of the thickened portion 251 is smaller than the thickness of the bottom wall 26 .

[0132] The maximum thickness of the thickened portion 251 is smaller than the thickness of the bottom wall 26 , so that the bottom wall 26 has a greater thickness and a higher strength.

[0133] Because the pressure relief mechanism 24 is disposed on the bottom wall 26, when the bottom wall 26 has a relatively high strength, the bottom wall 26 has an improved tensile strength, thereby reducing the risk of premature damage to the pressure relief mechanism 24. According to some embodiments of the present application, the thickness of the thickened portion 251 at any position along the circumferential direction P of the side wall is greater than the thickness of the main body portion 252.

[0134] In some embodiments, any position of the thickened portion 251 along the circumferential direction P of the side wall may have the same structure to facilitate processing and manufacturing.

[0135] In the above solution, the thickness of the thickened portion 251 at any position along the circumferential direction P of the side wall is greater than the thickness of the main body 252, so that the thickened portion 251 has higher strength in the circumferential direction P of the side wall, thereby improving the tensile strength of the shell 211.

[0136] Please refer to Figure 7, which is a schematic diagram of multiple thickened regions provided in some embodiments of the present application. According to some embodiments of the present application, the thickened portion 251 includes multiple thickened regions 251a, which are spaced apart along the circumferential direction P of the sidewall. The thickened portion 251 also includes a transition region 251b connecting any two adjacent thickened regions 251a. The thickness of the thickened region 251a is greater than the thickness of the main body 252, and the thickness of the thickened region 251a is greater than the thickness of the transition region 251b.

[0137] Along the circumferential direction P of the side wall, the thickness of the thickened portion 251 gradually increases from the end close to the transition zone 251b to the end away from the transition zone 251b, that is, a step surface is formed between the thickened portion 251 and the transition zone 251b to facilitate processing and manufacturing.

[0138] In some embodiments, the thickness of the transition zone 251b may be greater than or equal to the thickness of the main body 252. Optionally, the thickness of the transition zone 251b is the same as the thickness of the main body 252. This, on the one hand, facilitates the expansion of the material and facilitates the stamping and forming of the housing. On the other hand, it reduces the difficulty of stamping and demolding the housing, facilitating processing and manufacturing.

[0139] In the above scheme, multiple thickened areas 251a are arranged at intervals along the circumferential direction P of the side wall. On the one hand, it is convenient for the extension of the material and the stamping forming of the shell 211. On the other hand, it is convenient to reduce the difficulty of demolding the shell 211. Two adjacent thickened areas 251a are connected by a transition area 251b. The thickness of the thickened area 251a is greater than the thickness of the transition area 251b, which facilitates the processing and forming of the thickened area 251a.

[0140] Please refer to Figures 4 and 5. According to some embodiments of the present application, the side wall 25 includes two first side walls 25a arranged opposite to each other in the second direction Y, and two second side walls 25b arranged opposite to each other in the third direction Z; the first side wall 25a includes a first thickened portion 251c and a first main body portion 252a, and along the first direction X, the first thickened portion 251c is connected between the first main body portion 252a and the bottom wall 26; the second side wall 25b includes a second thickened portion 251d and a second main body portion 252b, and along the first direction X, the second thickened portion 251d is connected between the second main body portion 252b and the bottom wall 26; the two first thickened portions 251c and the two second thickened portions 251d are configured as the thickened portion 251, and the two first main body portions 252a and the two second main body portions 252b are configured as the main body portion 252; wherein, the maximum thickness of the first thickened portion 251c is greater than the thickness of the main body portion 252, and the maximum thickness of the second thickened portion 251d is greater than the thickness of the main body portion 252.

[0141] The structure of the first side wall 25a can be the same as or different from that of the second side wall 25b. Along the first direction X, the end of the first thickened portion 251c away from the bottom wall 26 can be flush with the end of the second thickened portion 251d away from the bottom wall 26 to facilitate processing and manufacturing.

[0142] The maximum thickness of the first thickened portion 251 c may be the maximum thickness of the thickened portion 251 , or the maximum thickness of the second thickened portion 251 d may be the maximum thickness of the thickened portion 251 .

[0143] In some embodiments, the structure of the first body portion 252a may be the same as that of the second body portion 252b, that is, the thickness of the first body portion 252a may be the same as that of the second body portion 252b to facilitate processing and manufacturing.

[0144] The first thickened portion 251c is the connection portion between the first side wall 25a and the bottom wall 26. The maximum thickness of the first thickened portion 251c is greater than the thickness of the main body 252, so that the connection portion between the first side wall 25a and the bottom wall 26 is thickened, so that the first thickened portion 251c has higher strength, and the shell 211 has higher tensile strength.

[0145] The second thickened portion 251d is the connection portion between the second side wall 25b and the bottom wall 26. The maximum thickness of the second thickened portion 251d is greater than the thickness of the main body 252, so that the connection portion between the second side wall 25b and the bottom wall 26 is thickened, so that the second thickened portion 251d has higher strength, and the shell 211 has higher tensile strength.

[0146] In the above scheme, the two ends of the first side wall 25a are respectively connected to the two second side walls 25b, and the two first side walls 25a and the two second side walls 25b form a space for accommodating the electrode assembly. The maximum thickness of any one of the first thickened portion 251c and the second thickened portion 251d is greater than the thickness of the main body 252. The first thickened portion 251c and the second thickened portion 251d both have high strength, so that the shell 211 has a high tensile strength.

[0147] According to some embodiments of the present application, the area of ​​the outer surface of the first side wall 25a is greater than the area of ​​the outer surface of the second side wall 25b, the maximum thickness of the first thickened portion 251c is greater than the thickness of the first main body portion 252a, and the maximum thickness of the second thickened portion 251d is greater than the thickness of the second main body portion 252b.

[0148] In some embodiments, the thickness of the first body portion 252a may be smaller than the thickness of the second body portion 252b.

[0149] In the above scheme, the first side wall 25a can be the large surface of the shell 211, the second side wall 25b can be the narrow surface of the shell 211, the maximum thickness of the first thickened portion 251c is greater than the thickness of the first main body portion 252a, and the maximum thickness of the second thickened portion 251d is greater than the thickness of the second main body portion 252b, so that the shell 211 has a higher tensile resistance.

[0150] Please refer to Figures 8 to 11. Figure 8 is an exploded schematic diagram of a battery cell according to other embodiments of the present application. Figure 9 is a schematic diagram of the structure of the sidewalls and bottom wall according to other embodiments of the present application. Figure 10 is a schematic diagram of the structure of the sidewalls according to some embodiments of the present application. Figure 11 is a partial enlarged view of point B in Figure 10. According to some embodiments of the present application, the housing 21 also includes a top wall 27. The sidewalls 25 include two first sidewalls 25a arranged opposite each other along the second direction Y. The top wall 27 and the bottom wall 26 are arranged opposite each other along the first direction X. The ends of the top wall 27 are respectively connected to the two first sidewalls 25a. The sidewall 25 is formed with two openings. The housing 21 also includes two end caps 212. The two end caps 212 are arranged opposite each other in the third direction Z, and the two end caps 212 respectively close the two openings.

[0151] In some embodiments, the electrode assembly includes a main body, a positive electrode tab and a negative electrode tab, the positive electrode tab and the negative electrode tab extend from both ends of the main body in the third direction Z, the positive electrode terminal is arranged at one end cover 212, and the negative electrode terminal is arranged at the other end cover 212, the positive electrode tab is electrically connected to the positive electrode terminal, and the negative electrode tab is electrically connected to the negative electrode terminal.

[0152] The provision of the two openings facilitates the assembly of the electrode assembly and the shell 211 on the one hand, and on the other hand, the positive electrode tab and the negative electrode tab can be provided at both ends of the main body in the third direction Z to facilitate the output or input of electrical energy at different positions.

[0153] According to some embodiments of the present application, an embodiment of the present application further provides a battery 100, which includes a battery cell 20 provided in any of the above embodiments.

[0154] According to some embodiments of the present application, an electrical device is further provided, which includes a battery cell 20 or a battery 100 as provided in any of the above embodiments, and the battery cell 20 or the battery 100 is used to provide electrical energy.

[0155] The electrical equipment may include, but is not limited to, any of the above-mentioned devices or systems using the battery cell 20 or the battery 100 .

[0156] According to some embodiments of the present application, an energy storage device is further provided, which includes a battery cell 20 or a battery 100 as provided in any of the above embodiments.

[0157] According to some embodiments of the present application, referring to FIG. 3 to FIG. 11 , embodiments of the present application provide a battery cell 20, which includes a housing 21, an electrode assembly 22, an electrode terminal 23, and a pressure relief mechanism 24. The housing 21 includes a shell 211 and an end cap 212. The shell 211 has an opening, and the end cap 212 closes the opening. The electrode assembly 22 is disposed within the housing 21, and the electrode terminal is disposed on the end cap 212. The housing 211 includes a side wall 25 and a bottom wall 26. The side wall 25 is disposed around the edge of the bottom wall 26. The side wall 25 includes a thickened portion 251 and a main body 252 distributed sequentially along a first direction X. The main body 252 is farther away from the bottom wall 26 relative to the thickened portion 251. The thickened portion 251 is connected to the bottom wall 26. The maximum thickness of the thickened portion 251 is greater than the thickness of the main body 252.

[0158] In some embodiments, referring to Figures 4 to 6, the sidewall 25 includes two first sidewalls 25a disposed opposite to each other in the second direction Y, and two second sidewalls 25b disposed opposite to each other in the third direction Z. The first sidewall 25a includes a first thickened portion 251c and a first main body portion 252a. Along the first direction X, the first thickened portion 251c is connected between the first main body portion 252a and the bottom wall 26. The second sidewall 25b includes a second thickened portion 251d and a second main body portion 252b. Along the first direction X, the second thickened portion 251d is connected between the second main body portion 252b and the bottom wall 26. The two first thickened portions 251c and the two second thickened portions 251d constitute the thickened portion 251, and the two first main bodies 252a and the two second main bodies 252b constitute the main body 252. The structure of the first main body portion 252a is identical to that of the second main body portion 252b, the maximum thickness of the first thickened portion 251c is greater than the thickness of the main body portion 252, and the maximum thickness of the second thickened portion 251d is greater than the thickness of the main body portion 252. The outer surface area of ​​the first side wall 25a is greater than the outer surface area of ​​the second side wall 25b.

[0159] In some embodiments, referring to Figures 8 to 11 , the housing 21 further includes a top wall 27. The sidewall 25 includes two first sidewalls 25a disposed opposite each other in the second direction Y. The top wall 27 and the bottom wall 26 are disposed opposite each other in the first direction X, with both ends of the top wall 27 connected to the two first sidewalls 25a. The sidewall 25 defines two openings. Two end caps 212 are disposed opposite each other in the third direction Z, and the two end caps 212 respectively close the two openings. The first sidewall 25a includes a first thickened portion 251c and a first main body portion 252a. Along the first direction X, the first thickened portion 251c is connected between the first main body portion 252a and the bottom wall 26. The first thickened portion 251c is configured as a thickened portion 251, and the first main body portion 252a is configured as a main body portion 252.

[0160] According to the battery cell 20 of the embodiment of the present application, the connection between the side wall 25 and the bottom wall 26 is thickened to improve the strength of the shell 211, which can improve the tensile strength of the shell 211 and reduce the risk of premature pressure relief and leakage of the pressure relief structure, so that the battery cell 20 has higher reliability.

[0161] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A battery cell, comprising: The housing comprises a shell, the shell comprising side walls and a bottom wall, the side walls being arranged around the edge of the bottom wall; a pressure relief mechanism, disposed on the bottom wall; In which, the side wall includes a thickened portion and a main body portion distributed in sequence along a first direction, the first direction is parallel to the thickness direction of the bottom wall, the main body portion is away from the bottom wall relative to the thickened portion, the thickened portion is connected to the bottom wall, and the maximum thickness of the thickened portion is greater than the thickness of the main body portion.

2. The battery cell according to claim 1, wherein: Along the first direction, the dimension of the thickened portion is h, and the dimension of the side wall is H, satisfying 0.5 mm ≤ h ≤ 0.5*H.

3. The battery cell according to claim 2, wherein: 1mm≤h≤2mm.

4. The battery cell according to any one of claims 1 to 3, wherein: The maximum thickness of the thickened portion is W1, and the thickness of the main body is W2, satisfying 0.05 mm ≤ W1 - W2 ≤ W2.

5. The battery cell according to claim 4, wherein: 0.2mm≤W1-W2≤0.8*W2.

6. The battery cell according to claim 4 or 5, wherein: 0.25mm≤W1≤2.4mm.

7. The battery cell according to claim 6, wherein: 0.8mm≤W1≤1.8mm.

8. The battery cell according to any one of claims 1 to 7, wherein: The maximum thickness of the thickened portion is smaller than the thickness of the bottom wall.

9. The battery cell according to any one of claims 1 to 8, wherein: Along the circumference of the side wall, the thickness of the thickened portion at any position is greater than the thickness of the main body portion.

10. The battery cell according to any one of claims 1 to 9, wherein: The thickened portion includes a plurality of thickened areas, and the plurality of thickened areas are arranged at intervals along the circumference of the side wall; The thickened portion further includes a transition zone connecting any two adjacent thickened zones, the thickness of the thickened zone is greater than the thickness of the main body portion, and the thickness of the thickened zone is greater than the thickness of the transition zone.

11. The battery cell according to any one of claims 1 to 10, wherein: The side walls include two first side walls arranged opposite to each other in the second direction, and two second side walls arranged opposite to each other in the third direction; The first side wall includes a first thickened portion and a first main body portion, and along the first direction, the first thickened portion is connected between the first main body portion and the bottom wall. The second side wall includes a second thickened portion and a second main body portion, and along the first direction, the second thickened portion is connected between the second main body portion and the bottom wall. Two first thickened portions and two second thickened portions constitute the thickened portion, and two first main bodies and two second main bodies constitute the main body portion. The maximum thickness of the first thickened portion is greater than the thickness of the main body portion, and the maximum thickness of the second thickened portion is greater than the thickness of the main body portion.

12. The battery cell according to claim 11, wherein: The outer surface area of ​​the first side wall is greater than the outer surface area of ​​the second side wall, the maximum thickness of the first thickened portion is greater than the thickness of the first main body portion, and the maximum thickness of the second thickened portion is greater than the thickness of the second main body portion.

13. A battery comprising the battery cell according to any one of claims 1 to 12.

14. An electrical device comprising the battery cell according to any one of claims 1 to 12 or the battery according to claim 13, wherein the battery cell or the battery is used to provide electrical energy.

15. An energy storage device comprising the battery cell according to any one of claims 1 to 12 or the battery according to claim 13.

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