Battery cells, batteries, power consumption equipment and energy storage devices

Abstract

Embodiments of the present application provide a battery cell, a battery, a power consumption device, and an energy storage device. The battery cell includes a shell. The shell includes a shell body and an end cap, the shell body having an opening, the shell body including two first walls facing each other along a first direction and two second walls facing each other along a second direction, the area of ​​the outer surface of the first walls being smaller than the area of ​​the outer surface of the second walls, the first wall including a first opening and a first body portion arranged sequentially along a third direction, the third direction being parallel to the thickness direction of the end cap, the first body portion being further from the opening than the first opening, the end cap being connected to the first and second walls to close the opening, the size of the first wall in the second direction being W1 and the size of the second wall in the first direction being W2 satisfying 0.2 ≤ W1 / W2, the thickness of the first opening being greater than the thickness of the first body portion, and the second, third, and first directions being perpendicular in pairs. The technical solution of this invention can improve the reliability of batteries.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and more specifically, to battery cells, batteries, power-consuming devices, and energy storage devices.

Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automotive industry, and electric vehicles have become an important component of the sustainable development of the automotive industry due to their energy conservation and environmental protection advantages. For electric vehicles, battery technology is also an important factor related to their development.

[0003] In the manufacturing process of batteries, the reliability of batteries is an issue that cannot be ignored. Therefore, how to improve the reliability of batteries is an issue to be solved in battery technology.

Summary of the Invention

[0004] This application provides a battery cell, a battery, a power-consuming device, and an energy storage device that can improve the reliability of the battery.

[0005] This application is realized by the following technical solutions.

[0006] In a first embodiment, an embodiment of the present application provides a battery cell including a shell. The shell includes a shell body and an end cap, the shell body having an opening, the shell body including two first walls facing each other along a first direction and two second walls facing each other along a second direction, the area of ​​the outer surface of the first walls being smaller than the area of ​​the outer surface of the second walls, the first wall including a first opening and a first body portion arranged sequentially along a third direction, the third direction being parallel to the thickness direction of the end cap, the first body portion being further from the opening than the first opening, the end cap being connected to the first and second walls to close the opening, the size of the first wall in the second direction being W1 and the size of the second wall in the first direction being W2 satisfying 0.2 ≤ W1 / W2, the maximum thickness of the first opening being greater than the thickness of the first body portion, and the second, third and first directions being perpendicular in pairs.

[0007] According to the battery cell of the embodiment of the present invention, the area of ​​the outer surface of the first wall is smaller than the area of ​​the outer surface of the second wall, and the first wall may be the narrow side of the battery cell. When the ratio of the size of the first wall in the second direction to the size of the second wall in the first direction satisfies the above relationship, the first opening is thickened, resulting in relatively high strength at the first opening. This reduces the risk of the shell body cracking when thermal runaway occurs near the welding area of ​​the shell body and the end cap, or when a large amount of gas is generated, thereby giving the battery cell relatively high reliability.

[0008] According to some embodiments of the present application, W1 / W2 ≤ 0.6.

[0009] In the above solution, if the ratio of the size of the first wall in the second direction to the size of the second wall in the first direction satisfies the above relationship, the risk of the shell body cracking near the welded area of ​​the shell body and the end cap can be reduced when the first opening has relatively high strength.

[0010] According to some embodiments of the present application, 0.25 ≤ W1 / W2 ≤ 0.35.

[0011] In the above solution, if 0.25 ≤ W1 / W2 ≤ 0.35 is used compared to 0.2 ≤ W1 / W2, the first opening is thickened, which effectively reduces the risk of the shell body cracking near the welding area of ​​the shell body and end cap, improves the manufacturability of the shell body, and further improves the reliability of the battery cell.

[0012] According to some embodiments of the present application, 50 mm ≤ W1 ≤ 90 mm, and preferably 60 mm ≤ W1 ≤ 86 mm.

[0013] In the above solution, if the size of the first wall in the second direction satisfies the above relationship, the first opening is thickened, thereby improving the strength at the first opening and reducing the risk of the shell body cracking near the welding area of ​​the shell body and end cap, while also facilitating processing and manufacturing. Compared to 50mm ≤ W1 ≤ 90mm, if 60mm ≤ W1 ≤ 86mm, the first opening is thickened, reducing the risk of the shell body cracking near the welding area of ​​the shell body and end cap, and the difficulty of processing and manufacturing is lower.

[0014] According to some embodiments of the present application, when the maximum thickness of the first opening is h1 and the thickness of the first main body is h2, the following conditions are satisfied: 0.55 ≤ h / W ≤ 2.5, h = (h1 - h2) / h2, and W = W1 / W2.

[0015] In the above solution, when the maximum thickness of the first opening, the thickness of the first main body, the size of the first wall in the second direction, and the size of the second wall in the first direction satisfy the above relationship, the first opening is thickened, resulting in the first opening having relatively high strength, reducing the risk of the shell body cracking near the welding area of ​​the shell body and end cap, facilitating the processing and manufacturing of the first opening, resulting in a relatively small space occupied by the first opening, and a relatively high energy density for the battery cell.

[0016] According to some embodiments of the present application, 0.6 ≦ h / W ≦ 1.8.

[0017] In the above solution, compared with 0.55 ≦ h / W ≦ 2.5, when 0.6 ≦ h / W ≦ 1.8, the space occupied by the first opening is relatively small, the difficulty of processing and manufacturing the first opening is relatively low, and the first opening has relatively high strength.

[0018] According to some embodiments of the present application, when the maximum thickness of the first opening is h1, the thickness of the first main body is h2, and the outer surface area of the first wall is S, (1 / 360000) mm -2 ≦ h / S ≦ (1 / 9000) mm -2 and h = (h1 - h2) / h2 is satisfied.

[0019] In the above solution, when the maximum thickness of the first opening, the thickness of the first main body, and the outer surface area of the first wall satisfy the above relationship, it facilitates processing and manufacturing, the first opening has relatively high strength, and it is possible to reduce the risk of the shell body cracking near the welding area of the shell body and the end cap. At the same time, the space occupied by the first opening is relatively small, and the battery cell has relatively high energy density.

[0020] According to some embodiments of the present application, (1 / 300000) mm <s>0000003< / s>≦ h / S ≦ (1 / 15000) mm -2 is satisfied.

[0021] In the above solution, compared with (1 / 360000) mm -2 ≦ h / S ≦ (1 / 9000) mm -2 when (1 / 300000) mm -2 ≦ h / S ≦ (1 / 15000) mm -2 is satisfied, the difficulty of processing and manufacturing is relatively low, the first opening has relatively high strength, and the space occupied by the first opening is relatively small.

[0022] According to some embodiments of the present application, 4500 mm 2 ≦ S ≦ 36000 mm 2 is satisfied. It should be noted that there seems to be an incorrect tag <s>0000003< / s> in the original text which is not in the correct format. It should be -2 . I have translated it as best as possible with the given content.

[0023] In the above solution, when the area of ​​the outer surface of the first wall satisfies the above relationship, the battery cell has a relatively high energy density, the processing and manufacturing of the first wall is facilitated, the first opening has relatively high strength, and the risk of the shell body cracking near the welding area of ​​the shell body and end cap is reduced.

[0024] According to some embodiments of the present application, 6000 mm 2 ≤S ≤ 22500mm 2 That is the case.

[0025] In the above solution, 4500mm 2 ≤S ≤ 36000mm 2 And, 6000mm 2 ≤S ≤ 22500mm 2 Therefore, if the battery cell has a relatively high energy density, the first opening will have relatively high strength, reducing the risk of the shell body cracking near the welded area of ​​the shell body and end cap.

[0026] According to some embodiments of the present application, h1 and h2 satisfy at least one of the following conditions: (1) 0.1 ≤ h ≤ 0.5, (2) 0.55 mm ≤ h1 ≤ 1.8 mm, and (3) 0.5 mm ≤ h2 ≤ 1.2 mm.

[0027] In the above solution, if the maximum thickness of the first opening and the thickness of the first main body satisfy the above relationship, processing and manufacturing are facilitated, the first opening has relatively high strength, the space occupied by the first opening is relatively small, and the battery cell has a relatively high energy density.

[0028] According to some embodiments of the present application, h1 and h2 satisfy at least one of the following conditions: (1) 0.15 ≤ h ≤ 0.3, (2) 0.69 mm ≤ h1 ≤ 1.56 mm, and (3) 0.6 mm ≤ h2 ≤ 0.8 mm.

[0029] In the above solution, compared to 0.1≦h≦0.5, 0.55mm≦h1≦1.8mm, and 0.5mm≦h2≦1.2mm, if the values ​​are 0.15≦h≦0.3, 0.69mm≦h1≦1.56mm, and 0.6mm≦h2≦0.8mm, the difficulty of processing and manufacturing is relatively low, the strength of the first opening is relatively high, and the space occupied by the first opening is relatively small.

[0030] According to some embodiments of the present application, the first opening includes a first segment and a second segment connected to each other, the first segment, the second segment and the first body are arranged sequentially along a third direction, the maximum thickness of the second segment is greater than the thickness of the first body, the maximum thickness of the second segment is greater than the maximum thickness of the first segment, a first stepped surface is formed between the second segment and the first segment, and an end cap is fitted to the first stepped surface and connected to the first segment.

[0031] In the above solution, the first segment, the second segment, and the first main body are arranged sequentially along the third direction, and the end cap and the first segment are connected so that the second segment is adjacent to the connection point between the end cap and the first segment, the first opening has relatively high strength, the risk of the shell body cracking near the welding area of ​​the shell body and the end cap is reduced, and the lifespan and reliability of the battery cell can be improved. The end cap is made into a first stepped surface so that positioning relative to the end cap can be achieved.

[0032] According to some embodiments of the present application, the second wall includes a second opening and a second body portion that are sequentially connected in a third direction, the second body portion being further from the opening than the second opening, the second opening being connected to an end cap, and the maximum thickness of the second opening being greater than the thickness of the second body portion.

[0033] In the above solution, the strength of the second wall can be increased by thickening the second opening, and because the strength of the second opening is increased during the charge-discharge cycle process of the battery cell, the risk of the shell body cracking due to fatigue near the welding area of ​​the shell body and end cap can be reduced.

[0034] According to some embodiments of the present invention, the shell body is a prismatic structure having openings at both ends, and the number of end caps is two, with each of the two end caps closing off two openings.

[0035] In the above solution, openings are provided at each end of the shell body, and both openings are thickened, thereby reducing the risk of the shell body cracking.

[0036] According to some embodiments of the present application, the battery cell further comprises an electrode assembly, the electrode assembly comprises a positive electrode sheet, the positive electrode sheet comprises a positive electrode active material, the positive electrode active material comprises a nickel-containing compound, the nickel-containing compound comprises a layered lithium-containing transition metal oxide, and the ratio of the molar amount of nickel in the layered lithium-containing transition metal oxide to the total molar amount of transition metal elements in the layered lithium-containing transition metal oxide is 50% or more.

[0037] In the above solution, the nickel element content is relatively high, and the battery cell has a relatively high energy density.

[0038] According to some embodiments of the present application, the layered lithium-containing transition metal oxide is Li a Ni b Co c M d O e A fIt includes, where 0 < a ≤ 1.2, 0.6 ≤ b < 1, 0 < c < 1, 0 < d < 1, 1 ≤ e ≤ 2, 0 ≤ f ≤ 1, M includes one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti, and B, but is not limited thereto, and A includes one or more of N, F, S, and Cl, but is not limited thereto.

[0039] In the above solution, the nickel content is relatively high, the energy density of the battery cell is relatively high, the first opening has relatively high strength, and it reduces the risk of the shell body cracking near the welding area of the shell body and the end cap.

[0040] According to some embodiments of the present application, 0.7 ≤ b ≤ 0.98.

[0041] In the above solution, the nickel content is relatively high, and the battery cell has a relatively high energy density.

[0042] According to some embodiments of the present application, 0.4 ≤ b / h ≤ 8.1.

[0043] In the above solution, the manufacturing difficulty of the battery cell is relatively low, the battery cell has a relatively high energy density, the thermal runaway and gas generation of the battery cell are relatively few, the first wall has relatively high strength, and the risk of the first wall cracking is relatively low.

[0044] According to some embodiments of the present application, 1 ≤ b / h ≤ 6.

[0045] In the above solution, compared with 0.4 ≤ b / h ≤ 8.1, when 1 ≤ b / h ≤ 6, the strength of the first wall is relatively high, the space occupied by the first opening is relatively small, the battery cell has a relatively high energy density, and the thermal runaway and gas generation of the battery cell are relatively few.

[0046] According to some embodiments of the present application, the battery cell further includes an electrode assembly, the electrode assembly includes a body, the body is provided with an active material, the body has a first surface facing an end cap, and the first opening extends beyond the first surface in a direction toward the first opening from the first body.

[0047] In the above solution, the risk of interference between the first opening and the body can be reduced by ensuring that the first opening extends beyond the first surface in the direction from the first main body towards the first opening.

[0048] According to some embodiments of the present application, the shell body and the end cap are welded together to form a welded region, and the average grain size of the portion of the first opening excluding the welded region is greater than the average grain size of the first main body, and the average grain size is the average grain size in the thickness direction of the first wall of the crystal grain.

[0049] In the above solution, the average grain size of the portion of the first opening excluding the welded area is larger than the average grain size of the first main body, which is advantageous for strengthening the first opening. As a result, the first opening has relatively high strength, and the risk of the shell body cracking near the welded area of ​​the shell body and end cap is reduced.

[0050] According to some embodiments of the present application, in a cross-section of the first wall parallel to the thickness direction of the first wall, the portion located below the welded area of ​​the first opening has 15 or more crystal grains in the width direction of the cross-section.

[0051] In the above solution, having 15 or more crystal grains in the width direction of the cross-section is advantageous for strengthening the first opening, thereby giving the first opening relatively high strength.

[0052] According to some embodiments of the present application, the average grain size range of the portion of the first opening excluding the welded area is 70 μm to 1200 μm, and / or the average grain size range of the first main body is 30 μm to 1000 μm.

[0053] In the above solution, if the average crystal grain size of the first opening and / or the average crystal grain size of the first main body satisfy the above relationship, it is advantageous for strengthening the strength of the first opening, thereby giving the first opening relatively high strength.

[0054] In a second embodiment, the embodiment of the present application provides a battery including a battery cell according to any of the embodiments described above.

[0055] According to some embodiments of the present invention, the number of battery cells is multiple, and the multiple battery cells are arranged in a stack along a second direction, and the battery further includes end plates, which are provided at the ends of the multiple battery cells along the second direction.

[0056] In the above solution, the end plates are provided at the ends of multiple battery cells in a second direction, and the end plates and the shell bodies of adjacent battery cells have a relatively large connection area, thereby creating constraints on the shell bodies and reducing the risk of the shell bodies cracking near the welding area between the shell bodies and the end caps.

[0057] According to some embodiments of the present application, the end plate is provided facing the second wall.

[0058] In the above solution, since the end plate is provided facing the second wall, the end plate and the second wall have a relatively large contact area, and in the charge-discharge cycle process of the battery cell, the end plate restricts the second wall, thereby reducing the risk of the shell body cracking near the welding area of ​​the shell body and end cap.

[0059] In a third embodiment, the embodiment of the present application provides a power consumption device including a battery cell or battery according to any of the embodiments described above.

[0060] In a fourth embodiment, an embodiment of the present application provides an energy storage device including a battery cell or battery according to any of the above embodiments.

[0061] The additional aspects and advantages of this application are partially described below, partially evident from the following description, or understood through the practice of this application. [Brief explanation of the drawing]

[0062] To more clearly explain the technical solutions of the embodiments of this application, the drawings necessary for the embodiments are briefly described below. It should be understood that the following drawings show only a few embodiments of this application and should not be considered as limiting the scope; those skilled in the art can obtain other relevant drawings based on these drawings without requiring any creative work. [Figure 1] This is a schematic diagram of the structure of a vehicle according to several embodiments of the present invention. [Figure 2] This is an exploded view of a battery according to some embodiments of the present invention. [Figure 3] This is an exploded view of a battery cell according to some embodiments of the present invention. [Figure 4] This is a perspective view of a battery cell according to some embodiments of the present application. [Figure 5] This is a cross-sectional view of a shell according to several embodiments of the present application. [Figure 6] This is a magnified view of point A in Figure 5. [Figure 7] This is a schematic diagram of the structure of the first wall according to some embodiments of the present application. [Figure 8] This is a schematic diagram of the structure of the second wall according to some embodiments of the present application. [Figure 9] This is a cross-sectional view of a part of the structure after the end cap and shell shell have been assembled according to some embodiments of the present application. [Figure 10] This is a schematic diagram of the assembly of an end cap and a battery cell according to several embodiments of the present invention. [Figure 11] These are schematic diagrams illustrating the assembly of the end cap and battery cell at the end according to several embodiments of the present invention. The drawings are not drawn to actual scale. [Explanation of Symbols]

[0063] 100 batteries 10 cabinets 11. First Sub-Cabinet 12. Second Sub-Cabinet 20 battery cells 21 Shell 21a Shell body 21b End cap 211 1st wall 2111 First opening 2111a First segment 2111b Second segment 2112 First main body 2113 1st step surface 212 Second wall 2121 Second opening 2122 Second Main Body 213 Bottom wall 210 Welding Area 22 Electrode Assembly 221 Torso 221a 1st surface 222 tabs 23 Electrode terminal 30 End Plates 200 controllers 300 motor 1000 vehicles X 3rd direction Y Second direction Z 1st direction [Modes for carrying out the invention]

[0064] To further clarify the purpose, technical solutions, and advantages of the embodiments of this application, the technical solutions in the embodiments of this application will be clearly described below with reference to the drawings of the embodiments. However, it is clear that the embodiments described are only some of the embodiments of this application, not all of them. All other embodiments that can be obtained by a person skilled in the art without creative work based on the embodiments of this application are all within the scope of protection of this application.

[0065] Unless otherwise defined, all technical and scientific terms used in this Application have the same meaning as that ordinarily understood by a person skilled in the art. In this Application, terms used in the Specification are for the sole purpose of describing specific embodiments and are not intended to limit the Application. The terms “includes” and “has” and any variations thereof in the Description of the Specification, Claims and the Drawings are intended to cover non-exclusive “inclusion.” Terms such as “first,” “second,” etc., in the Specification, Claims or the Drawings are for the purpose of distinguishing different subjects and are not intended to describe a particular order or hierarchical relationship.

[0066] As used in this application, “Examples” means that certain features, structures, or properties described with reference to the Examples are encompassed in at least one Example of this Application. The term, appearing in various parts of the Specification, does not necessarily refer to the same Example, nor does it mean that any Example is exclusive, independent, or alternative to the others. Those skilled in the art will understand, either explicitly or implicitly, that the Examples described in this Application can be combined with other Examples.

[0067] In the description of this application, unless otherwise specified and limited, the terms “attachment,” “connection,” “connection,” and “adhesion” should be understood in a broad sense. For example, the connection may be fixed, detachable, integral, directly, indirectly via an intermediate medium, or internal communication between two elements. A person skilled in the art will be able to understand the specific meaning of the above terms in this application depending on the specific circumstances.

[0068] In this application, the terms "and / or" are merely used to describe the relationship between related objects, indicating that three types of relationships are possible. For example, A and / or B can represent three situations: A existing alone, A and B existing simultaneously, and B existing alone. In addition, the symbol " / " in this application generally indicates that the related objects before and after it are in an "or" relationship.

[0069] In this application, "multiple" means two or more (including two), similarly, "multiple groups" means two or more groups (including two groups), and "multiple sheets" means two or more sheets (including two sheets).

[0070] In some embodiments, the battery may be a battery module, and if there are multiple battery cells, the multiple battery cells are arranged and fixed together to form a single battery module.

[0071] In some embodiments, the battery may be a battery pack, which includes a housing and battery cells, and the battery cells or battery modules are housed in the housing.

[0072] In some embodiments, the housing may be used as part of the vehicle's chassis structure. For example, part of the housing may be at least part of the vehicle's floor, and part of the housing may be at least part of the vehicle's crossbeams and longitudinal beams.

[0073] In some embodiments, the battery may be an energy storage device. The energy storage device includes energy storage containers, energy storage cabinets, and the like.

[0074] In the embodiments of this invention, the battery cell may be a secondary battery, which refers to a battery cell that can be continuously used by activating the active material by charging after the battery cell has been discharged.

[0075] The battery cell may be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., but is not limited to these.

[0076] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a battery cell, active ions (e.g., lithium ions) reciprocate between the positive and negative electrodes, being intercepted and released. The separator is placed between the positive and negative electrodes and serves to prevent short circuits between them while allowing active ions to pass through.

[0077] 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 provided on at least one surface of the positive electrode current collector.

[0078] As an example, the positive electrode current collector has two opposing surfaces in the thickness direction of itself, and the positive electrode active material is provided on one or both of the two opposing surfaces of the positive electrode current collector.

[0079] As an example, the positive electrode current collector may be a metal foil sheet or a composite current collector. For example, the metal foil sheet may be silver-plated aluminum, silver-plated stainless steel, stainless steel, copper, aluminum, nickel, carbide-finished electrodes, carbon, nickel, or titanium. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy) on a polymer material substrate (for example, a substrate such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0080] As an example, the positive electrode active material may include at least one of lithium-containing phosphates, lithium transition metal oxides, and modified compounds thereof. However, the present invention is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may be used.

[0081] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0082] As an example, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, silver-plated aluminum, silver-plated stainless steel, stainless steel, copper, aluminum, nickel, or carbon, nickel, or titanium may be used for the carbide-finished electrode.

[0083] In some embodiments, the negative electrode current collector has two opposing surfaces in the thickness direction of itself, and the negative electrode active material is provided on one or both of the two opposing surfaces of the negative electrode current collector.

[0084] As an example, the negative electrode active material may be a negative electrode active material used in batteries known in the art. For example, the negative electrode active material may include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate. The silicon-based material may be at least one selected from elemental silicon, silicon-oxygen compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be at least one selected from elemental tin, tin-oxy compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for batteries may be used. These negative electrode active materials may be used individually or in combination of two or more.

[0085] In some embodiments, the separator is a separator film. The present application is not particularly limited to the type of separator film, and any known porous separator film having good chemical and mechanical stability can be selected.

[0086] As an example, the main material of the separator film may be at least one selected from glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator film may be a single-layer film or a multi-layer composite film, and is not particularly limited. If the separator film is a multi-layer composite film, the materials of each layer may be the same or different, and is not particularly limited. The separator may be a single component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0087] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is placed between the positive and negative electrodes and simultaneously performs the functions of ion transport and separation of the positive and negative electrodes.

[0088] In some embodiments, the electrode assembly is a wound structure. A positive electrode sheet and a negative electrode sheet are wound around the wound structure.

[0089] In some embodiments, the electrode assembly is a laminated sheet structure.

[0090] In some embodiments, the battery cell may include a shell. The shell is used to enclose components such as the electrode assembly and electrolyte. The shell may be a steel shell, an aluminum shell, a plastic shell (e.g., polypropylene), a composite metal shell (e.g., a copper-aluminum composite shell), or an aluminum-plastic film.

[0091] In some embodiments, the shell includes an end cap and a shell body, the shell body having an opening, and the end cap closing the opening to form a closed space for housing materials such as an electrode assembly and an electrolyte. The shell body may have one or more openings. The end cap may also have one or more.

[0092] In some embodiments, the shell 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 intermediate member. The electrode terminal may be provided on the end cap or on the shell body.

[0093] In some embodiments, the shell is provided with an explosion-proof valve. The explosion-proof valve is used to release the internal pressure of the battery cell.

[0094] For example, a battery cell may be a prismatic battery cell or a battery cell of another shape, and prismatic battery cells include square-shelled battery cells, blade-shaped battery cells, and polygonal prismatic batteries, and polygonal prismatic batteries are, for example, hexagonal prismatic batteries.

[0095] The development of battery technology requires the simultaneous consideration of various design elements, such as performance parameters including energy density, discharge capacity, and charge / discharge rate, as well as the reliability of the battery.

[0096] In some embodiments, the battery cell includes a shell, the shell includes a shell body and an end cap, the shell body having an opening, and the end cap closing the opening. The end cap is usually welded to the shell body, thereby strengthening the connection between the end cap and the shell body. The high temperature from the welding of the end cap and the shell body affects the performance of the end cap and the shell body, reducing the strength of the area near the weld joint, which may be called the heat-affected area. If the battery cell experiences thermal runaway or if a large amount of gas is generated inside the battery cell, the narrow face of the battery cell is not constrained, making it susceptible to affecting the heat-affected area of ​​the narrow face, which can cause the heat-affected area of ​​the narrow face to rupture, resulting in a relatively low reliability of the battery cell.

[0097] In view of this, in order to solve the problem of the shell body cracking due to fatigue and the reliability of the battery cell being relatively low, embodiments of the present invention provide the following technical solutions, wherein the battery cell includes a shell, and the shell includes a shell body and an end cap. The shell body has an opening, and the shell body includes two first walls facing each other along a first direction and two second walls facing each other along a second direction, the area of ​​the outer surface of the first walls being smaller than the area of ​​the outer surface of the second walls, and the first wall includes a first opening and a first body portion arranged sequentially along a third direction, the third direction being parallel to the thickness direction of the end cap, the first body portion being further from the opening than the first opening, and the end cap being connected to the first and second walls to close the opening. If the size of the first wall in the second direction is W1 and the size of the second wall in the first direction is W2, then the condition 0.2 ≤ W1 / W2 ≤ 0.5 is satisfied, the thickness of the first opening is greater than the thickness of the first main body, and the second, third, and first directions are perpendicular in pairs. This technical solution can improve the strength of the shell body and reduce the risk of the shell body cracking near the welding area between the shell body and the end cap, thereby giving the battery cell relatively high reliability.

[0098] In such a battery cell, the area of ​​the outer surface of the first wall is smaller than the area of ​​the outer surface of the second wall, and the first wall may be the narrow side of the battery cell. When the ratio of the size of the first wall in the second direction to the size of the second wall in the first direction satisfies the above relationship, the first opening is thickened, resulting in relatively high strength at the first opening and reducing the risk of the shell body cracking near the welding area of ​​the shell body and end cap, thereby giving the battery cell relatively high reliability.

[0099] The batteries disclosed in the embodiments of this application may be used in power-consuming devices such as vehicles, ships, or aircraft, but are not limited to these uses. A power supply system comprising such a power-consuming device, comprising the batteries disclosed in this application, can be used.

[0100] Embodiments of the present invention provide power-consuming devices that use batteries as a power source, and power-consuming devices may be, but are not limited to, mobile phones, tablets, laptop computers, electric toys, power tools, electric bicycles, electric motorcycles, electric automobiles, ships, aircraft, and spacecraft. Electric toys may include stationary or mobile electric toys such as game consoles, electric vehicle toys, electric boat toys, and electric aircraft toys, and aircraft and spacecraft may include aircraft, rockets, space shuttles, and spacecraft.

[0101] The following embodiments will be described using the example that the power-consuming device in one embodiment of the present invention is a vehicle 1000, for the sake of clarity.

[0102] Referring to Figure 1, Figure 1 is a schematic diagram of the structure of a vehicle according to several embodiments of the present application. The vehicle 1000 may be a gasoline vehicle, a diesel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range extender vehicle. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be located at the bottom, top, or rear of the vehicle 1000. The battery 100 may be used to supply power to the vehicle 1000, for example, the battery 100 may be used as the operating power source for the vehicle 1000 and may be used in the circuit system of the vehicle 1000, for example, to meet the operating power consumption requirements for starting the vehicle 1000, navigation, and driving.

[0103] The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being used to control the power supply to the motor 300 by the battery 100, for example, to meet the operating power consumption needs of the vehicle 1000 during startup, navigation, and driving.

[0104] In some embodiments of the present invention, the battery 100 is used not only as an operating power source for the vehicle 1000, but also as a power source for driving the vehicle 1000, and can provide driving power to the vehicle 1000 as a substitute or partial substitute for gasoline or natural gas.

[0105] Referring to Figure 2, which is an exploded view of a battery according to some embodiments of the present invention, the battery 100 includes a housing 10 and a battery cell 20, the battery cell 20 being housed within the housing 10. The housing 10 is used to provide a housing space for the battery cell 20, and the housing 10 may employ various structures. In some embodiments, the housing 10 includes a first sub-housing 11 and a second sub-housing 12, the first sub-housing 11 and the second sub-housing 12 being closed to each other, and the first sub-housing 11 and the second sub-housing 12 jointly defining a housing space for housing the battery cell 20. The second sub-casing 12 may be a hollow structure with one end open, and the first sub-casing 11 may be a plate-like structure. The first sub-casing 11 is closed to the open side of the second sub-casing 12, so that the first sub-casing 11 and the second sub-casing 12 jointly define a housing space. Both the first sub-casing 11 and the second sub-casing 12 may be hollow structures with one end open, and the open side of the first sub-casing 11 is closed to the open side of the second sub-casing 12.

[0106] 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 double row. A double row connection means that there are not only series connections but also parallel connections among the multiple battery cells 20. Multiple battery cells 20 may be directly connected in series, in parallel, or in a double row, and then the entire structure composed of the multiple battery cells 20 may be housed in the housing 10. Of course, the battery 100 may also be such that multiple battery cells 20 are connected in series, in parallel, or in a double row to form a battery module, and then multiple battery modules are connected in series, in parallel, or in a double row to form a single whole, which is then housed in the housing 10. The battery 100 may further include other structures. For example, the battery 100 may further include busbar members for realizing electrical connections between the multiple battery cells 20.

[0107] The battery cell 20 may be a secondary battery or a primary battery, and may be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these.

[0108] Referring to Figure 3, which is an exploded view of a battery cell according to some embodiments of the present application, the battery cell 20 includes a shell 21, an electrode assembly 22, and other functional components. The shell 21 includes a shell body 21a and an end cap 21b, the shell body 21a having an opening, and the end cap 21b closing the opening to isolate the internal environment of the battery cell 20 from the external environment.

[0109] The shell body 21a, together with the end cap 21b, is an assembly for forming the internal environment of the battery cell 20, which may be used to house the electrode assembly 22, electrolyte, and other components. The shell body 21a and the end cap 21b may be independent components. The shell body 21a may have various shapes and sizes. Specifically, the shape of the shell body 21a can be determined according to the specific shape and size of the electrode assembly 22. The shell body 21a may be made of various materials such as copper, iron, aluminum, stainless steel, and aluminum alloys (e.g., aluminum-manganese alloys).

[0110] The end cap 21b refers to a component that closes over the opening of the shell body 21a, thereby isolating the internal environment of the battery cell 20 from the external environment. The shape of the end cap 21b is not limited and can be made to match the shape of the shell body 21a in order to fit the shell body 21a. Preferably, the end cap 21b may be made of a material having a certain hardness and strength (for example, an aluminum alloy), so that the end cap 21b is less likely to deform when subjected to pressure or impact, thereby allowing the battery cell 20 to have higher structural strength and improved reliability. Functional components such as electrode terminals 23 may be provided on the end cap 21b. The electrode terminals 23 may be used to electrically connect to the electrode assembly 22 in order to output or input electrical energy from the battery cell 20. The end cap 21b may be made of various materials such as copper, iron, aluminum, stainless steel, and aluminum alloy, and is not particularly limited in the embodiments of this application. In some embodiments, an insulating structure may be provided inside the end cap 21b, which may be used to isolate the electrical connecting members in the shell body 21a from the end cap 21b in order to reduce the risk of short circuits. For example, the insulating structure may be made of plastic, rubber, or the like.

[0111] The electrode assembly 22 is a component in the battery cell 20 that undergoes an electrochemical reaction. The shell body 21a may contain one or more electrode assemblies 22. The electrode assembly 22 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet. Typically, a separator film is provided between the positive electrode sheet and the negative electrode sheet. The separator film is used to isolate the positive electrode sheet and the negative electrode sheet so that they do not short-circuit by being in contact with each other. The positive electrode sheet and the negative electrode sheet have portions containing active material that constitute the body of the electrode assembly, and portions without active material that constitute tabs. The positive electrode tab and the negative electrode tab may be located together at one end of the body, or at opposite ends of the body, respectively.

[0112] Referring to Figure 3, and further to Figures 4 to 6, Figure 4 is a perspective view of a battery cell according to some embodiment of the present application, Figure 5 is a cross-sectional view of a shell body according to some embodiment of the present application, a cross-sectional view of the shell body before assembly with the end cap, and Figure 6 is a partial enlargement of A in Figure 5. Embodiments of the present application provide a battery cell 20 including a shell 21. The shell 21 includes a shell body 21a and an end cap 21b, the shell body 21a having an opening, and the shell body 21a includes two first walls 211 facing each other along a first direction Z and two second walls 212 facing each other along a second direction Y, the outer surface area of ​​the first walls 211 being smaller than the outer surface area of ​​the second walls 212. The first wall 211 includes a first opening 2111 and a first body portion 2112 arranged sequentially along a third direction X, the third direction X being parallel to the thickness direction of the end cap 21b, the first body portion 2112 being further from the opening than the first opening 2111, and the end cap 21b being connected to the first wall 211 and the second wall 212 to close the opening. If the size of the first wall 211 in the second direction Y is W1 and the size of the second wall 212 in the first direction Z is W2, then the condition 0.2 ≤ W1 / W2 is satisfied, the maximum thickness of the first opening 2111 is greater than the thickness of the first body portion 2112, and the second direction Y, the third direction X, and the first direction Z are perpendicular in pairs.

[0113] In the figure, the direction indicated by the letter X may be the third direction, the direction indicated by the letter Y may be the second direction, and the direction indicated by the letter Z may be the first direction. The third direction X is parallel to the thickness direction of the end cap 21b, and the third direction X may be parallel to the height direction of the battery cell 20. The second direction Y may be parallel to the width direction of the battery cell 20. The first direction Z may be parallel to the length direction of the battery cell 20.

[0114] The first wall 211 and the second wall 212 are provided adjacent to each other, and the first wall 211 and the second wall 212 may also be adjacent side walls of the shell body 21a, and the same ends of the two first walls 211 and the two second walls 212 surround each other to form an opening, and the end cap 21b is connected to the two first walls 211 and the two second walls 212 to close the opening. The two first walls 211 and the two second walls 212 surround each other to form a housing chamber for housing the electrode assembly 22.

[0115] The area of ​​the outer surface of the first wall 211 is the area of ​​the surface of the first wall 211 that faces away from the inside of the battery cell 20. The area of ​​the outer surface of the second wall 212 is the area of ​​the surface of the second wall 212 that faces away from the inside of the battery cell 20. The area of ​​the outer surface of the first wall 211 is smaller than the area of ​​the outer surface of the second wall 212, and the first wall 211 may be a surface of the shell body 21a with a relatively small area, for example, the first wall 211 may be the narrow surface of the battery cell 20.

[0116] The first opening 2111 and the first main body portion 2112 are arranged sequentially along the third direction X, with the first main body portion 2112 being further from the opening than the first opening 2111, and thus the first opening 2111 being closer to the end cap 21b than the first main body portion 2112.

[0117] The size of the first wall 211 in the second direction Y is smaller than the size of the second wall 212 in the first direction Z, and the area of ​​the outer surface of the first wall 211 is smaller than the area of ​​the outer surface of the second wall 212. As a result, the size of the first wall 211 in the second direction Y may be the size of the shell body 21a in the second direction Y, and the size of the second wall 212 in the first direction Z may be the size of the shell body 21a in the first direction Z.

[0118] In some embodiments, the first main body portion 2112 may have a uniform thickness structure, and the thickness of the first main body portion 2112 may be the maximum thickness of the first main body portion 2112. The first opening 2111 may have a uniform thickness structure or a differential thickness structure. If the first opening 2111 has a uniform thickness structure, the maximum thickness of the first opening 2111 is the thickness at any position of the first opening 2111. If the first opening 2111 has a differential thickness structure, the maximum thickness of the first opening 2111 may be the thickness at the position where the thickness of the first opening 2111 is maximum.

[0119] Preferably, if the first opening 2111 has a differential thickness structure, the thickness of the first opening 2111 gradually decreases from the end furthest from the first main body 2112 to the end closer to the first main body 2112, and the region where the thickness of the first opening 2111 is maximum may be located at the end furthest from the first main body 2112.

[0120] According to the battery cell 20 of the embodiment of the present application, the area of ​​the outer surface of the first wall 211 is smaller than the area of ​​the outer surface of the second wall 212, and the first wall 211 may be the narrow side of the battery cell 20. When the ratio of the size of the first wall 211 in the second direction Y to the size of the second wall 212 in the first direction Z satisfies the above relationship (0.2 ≤ W1 / W2), the first opening 2111 is thickened, resulting in relatively high strength at the first opening 2111. This reduces the risk of the shell body 21a cracking when the battery cell 20 experiences thermal runaway or when a large amount of gas is generated near the welding area of ​​the shell body 21a and the end cap 21b, thereby providing the battery cell 20 with relatively high reliability.

[0121] Preferably, W1 / W2 may be 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.6, 0.7, 0.8, 0.9, etc., but is not limited to these.

[0122] In some embodiments, the first main body portion 2112 has a first surface facing the inside of the battery cell 20 along the thickness direction of the first wall 211, and a portion of the first opening 2111 may protrude from the first surface.

[0123] In some embodiments, the first main body portion 2112 has a second surface facing away from the inside of the battery cell 20 along the thickness direction of the first wall 211, and a portion of the first opening 2111 may protrude from the second surface.

[0124] In some embodiments, along the thickness direction of the first wall 211, the first main body portion 2112 has a first surface facing the inside of the battery cell 20 and a second surface facing away from the inside of the battery cell 20, and a portion of the first opening 2111 may protrude from the first surface, and a portion of the first opening 2111 may protrude from the second surface.

[0125] In some embodiments, the first opening 2111 may be provided separately or integrally molded. For example, in the manufacturing process of the shell body 21a, at the opening of the first wall 211, the thickened portion is provided separately from the base of the first wall 211, and the thickened portion is fixedly connected to the base to form the first opening 2111, and the region of the base that is in the first main body portion 2112 of the first wall 211 constitutes the first main body portion 2112. Alternatively, for example, in the manufacturing process of the shell body 21a, the shell body 21a is an integrally molded structure, and the shell body 21a is press-formed, and the first opening 2111 is formed at the opening of the first wall 211, and the maximum thickness of the first opening 2111 is greater than the thickness of the first main body portion 2112.

[0126] In some embodiments, if there is a difference in thickness between the first opening 2111 and the first main body portion 2112, and a part of the first opening 2111 protrudes from the first surface, a groove may be formed between the first opening 2111 and the first surface of the first main body portion 2112, and the body portion 221 of the electrode assembly 22 may be provided in the groove, or the body portion 221 may not be in the groove. The groove is a recessed region formed by the step difference between the first opening and the first main body portion.

[0127] According to some embodiments of the present application, W1 / W2 ≤ 0.6.

[0128] In the above solution, if the ratio of the size of the first wall 211 in the second direction Y to the size of the second wall 212 in the first direction Z satisfies the above relationship, then when the first opening 2111 has relatively high strength, the risk of the shell body 21a cracking near the welded area of ​​the shell body 21a and the end cap 21b can be reduced. According to some embodiments of the present application, 0.25 ≤ W1 / W2 ≤ 0.35.

[0129] Preferably, W1 / W2 may be 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, etc., but is not limited to these.

[0130] In the above solution, if 0.25 ≤ W1 / W2 ≤ 0.35 is obtained compared to 0.2 ≤ W1 / W2, the first opening 2111 is thickened, which effectively reduces the risk of the shell body 21a cracking near the welding area of ​​the shell body 21a and the end cap 21b, improves the manufacturability of the shell body, and further improves the reliability of the battery cell 20.

[0131] According to some embodiments of the present application, 50 mm ≤ W1 ≤ 90 mm, and preferably 60 mm ≤ W1 ≤ 86 mm.

[0132] Preferably, W1 may be 50mm, 52mm, 54mm, 56mm, 58mm, 60mm, 62mm, 64mm, 66mm, 68mm, 70mm, 72mm, 74mm, 76mm, 78mm, 80mm, 82mm, 84mm, 86mm, 88mm, 90mm, etc., but is not limited to these.

[0133] In the above solution, if the size of the first wall 211 in the second direction Y satisfies the above relationship (50 mm ≤ W1 ≤ 90 mm), the first opening 2111 is thickened, thereby improving the strength at the first opening 2111 and reducing the risk of the shell body 21a cracking near the welding area of ​​the shell body 21a and the end cap 21b, while also facilitating processing and manufacturing. Compared to 50 mm ≤ W1 ≤ 90 mm, if the size is 60 mm ≤ W1 ≤ 86 mm, the first opening 2111 is thickened, which reduces the risk of the shell body 21a cracking near the welding area of ​​the shell body 21a and the end cap 21b, and the difficulty of processing and manufacturing is lower.

[0134] According to some embodiments of the present application, when the maximum thickness of the first opening 2111 is h1 and the thickness of the first main body 2112 is h2, the following conditions are satisfied: 0.55 ≤ h / W ≤ 2.5, h = (h1 - h2) / h2, and W = W1 / W2.

[0135] h may be the thickness ratio of the first opening 2111 relative to the first main body 2112, and W is the ratio of the size of the first wall 211 in the second direction Y to the size of the second wall 212 in the first direction Z.

[0136] If h is too large, the space occupied by the first opening 2111 is relatively large, affecting the energy density of the battery cell 20 and increasing the difficulty of manufacturing the shell body 21a. If W is too small, the shell body 21a is prone to cracking at the second wall 212, and the effect of thickening the first wall 211 on preventing cracking of the shell body 21a is relatively low.

[0137] If W is too large or h is too small, the expansion force acting on the shell body 21a will be large, the thickness of the first opening 2111 will be relatively small, the strength of the first wall 211 will not be sufficient, and the first wall 211 will be prone to cracking.

[0138] In the above solution, when the maximum thickness of the first opening 2111, the thickness of the first main body 2112, the size of the first wall 211 in the second direction Y, and the size of the second wall 212 in the first direction Z satisfy the above relationship, the first opening 2111 is thickened, which gives the first opening 2111 relatively high strength, reduces the risk of the shell body 21a cracking near the welding area of ​​the shell body 21a and the end cap 21b, facilitates the processing and manufacturing of the first opening 2111, results in a relatively small space occupied by the first opening 2111, and gives the battery cell 20 a relatively high energy density.

[0139] h / W may be any value between 0.55 and 2.5. Preferably, h / W may be 0.55, 0.65, 0.75, 0.85, 0.95, 1.05, 1.15, 1.25, 1.35, 1.45, 1.55, 1.65, 1.75, 1.85, 1.95, 2.05, 2.15, 2.25, 2.35, 2.45, 2.5, etc., but is not limited to these.

[0140] According to some embodiments of the present application, W2 satisfies the condition 83 mm ≤ W2 ≤ 450 mm.

[0141] Preferably, W2 may be 83mm, 85mm, 90mm, 95mm, 100mm, 120mm, 150mm, 200mm, 250mm, 300mm, 350mm, 400mm, 410mm, 420mm, 430mm, 440mm, 450mm, etc., but is not limited to these.

[0142] According to some embodiments of this application, 0.6 ≤ h / W ≤ 1.8.

[0143] Preferably, h / W may be 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, etc., but is not limited to these.

[0144] In the above solution, when 0.6 ≤ h / W ≤ 1.8 is used, compared to 0.55 ≤ h / W ≤ 2.5, the space occupied by the first opening 2111 is relatively small, the difficulty of processing and manufacturing the first opening 2111 is relatively low, and the first opening 2111 has relatively high strength.

[0145] According to some embodiments of the present application, if the maximum thickness of the first opening 2111 is h1, the thickness of the first main body 2112 is h2, and the area of ​​the outer surface of the first wall 211 is S, then (1 / 360000) mm -2 ≤h / S ≤ (1 / 9000) mm -2 This satisfies the condition h = (h1 - h2) / h2.

[0146] The outer surface area S of the first wall 211 is obtained by multiplying the size of the shell body 21a in the second direction Y by the size of the first wall 211 in the third direction X.

[0147] In the above solution, the maximum thickness of the first opening 2111, the thickness of the first main body 2112, and the area of ​​the outer surface of the first wall 211 are related by the above relationship ((1 / 360000) mm -2 ≤h / S ≤ (1 / 9000) mm -2 When the condition h=(h1-h2) / h2) is satisfied, processing and manufacturing are facilitated, the first opening 2111 has relatively high strength, the risk of the shell body 21a cracking near the welding area of ​​the shell body 21a and end cap 21b is reduced, and the space occupied by the first opening 2111 is relatively small, allowing the battery cell 20 to have a relatively high energy density.

[0148] h / S is (1 / 360000) mm -2 From (1 / 9000) mm -2 It may be any value. Preferably, h / S is (1 / 360000) mm -2 , (1 / 300000) mm -2 , (1 / 250000) mm -2 , (1 / 200000) mm -2 , (1 / 150000) mm -2 , (1 / 100000) mm -2(1 / 50000) mm -2 , (1 / 10000) mm -2 , (1 / 9000) mm -2 These are also acceptable, but are not limited to these.

[0149] According to some embodiments of this application, (1 / 300000) mm -2 ≤h / S ≤ (1 / 15000) mm -2 That is the case.

[0150] In the above solution, (1 / 360000) mm -2 ≤h / S ≤ (1 / 9000) mm -2 Compared to (1 / 300000) mm -2 ≤h / S ≤ (1 / 15000) mm -2 In this case, the difficulty of processing and manufacturing is relatively low, the first opening 2111 has relatively high strength, and the space occupied by the first opening 2111 is relatively small.

[0151] Preferably, h / S is (1 / 300000) mm -2 , (1 / 200000) mm -2 , (1 / 100000) mm -2 , (1 / 50000) mm -2 , (1 / 40000) mm -2 , (1 / 30000) mm -2 , (1 / 20000) mm -2 (1 / 15000) mm -2 These are also acceptable, but are not limited to these.

[0152] According to some embodiments of this application, (1 / 240000) mm -2 ≤h / S ≤ (1 / 22500) mm -2 That is the case.

[0153] According to some embodiments of this application, 4500 mm 2 ≤S ≤ 36000mm 2 That is the case.

[0154] Preferably, S is 4500 mm 2 , 5000mm2 , 6000mm 2 , 10000mm 2 , 20000mm 2 , 30000mm 2 , 36000mm 2 These are also acceptable, but are not limited to these.

[0155] In the above solution, when the area of ​​the outer surface of the first wall 211 satisfies the above relationship, the battery cell 20 has a relatively high energy density, the processing and manufacturing of the first wall 211 is facilitated, the first opening 2111 has relatively high strength, and the risk of the shell body 21a cracking near the welding area of ​​the shell body 21a and the end cap 21b is reduced.

[0156] According to some embodiments of the present application, 6000 mm 2 ≤S ≤ 22500mm 2 That is the case.

[0157] Preferably, S is 6000 mm 2 , 6500mm 2 , 7000mm 2 , 7500mm 2 , 8000mm 2 , 9000mm 2 , 10000mm 2 , 11000mm 2 , 12000mm 2 , 13000mm 2 , 14000mm 2 , 15000mm 2 , 16000mm 2 , 17000mm 2 , 18000mm 2 , 19000mm 2 , 20000mm 2 , 21000mm 2 , 21500mm 2 , 22000mm 2 , 22500mm 2 These are also acceptable, but are not limited to these.

[0158] In the above solution, 4500mm 2≤S ≤ 36000mm 2 And, 6000mm 2 ≤S ≤ 22500mm 2 Therefore, if the battery cell 20 has a relatively high energy density, the first opening 2111 has relatively high strength, reducing the risk of the shell body 21a cracking near the welded area of ​​the shell body 21a and the end cap 21b.

[0159] According to some embodiments of the present application, h1 and h2 satisfy at least one of the following conditions: (1) 0.1 ≤ h ≤ 0.5, (2) 0.55 mm ≤ h1 ≤ 1.8 mm, and (3) 0.5 mm ≤ h2 ≤ 1.2 mm.

[0160] Preferably, h may be 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.48, 0.5, etc., but is not limited to these.

[0161] Preferably, h1 may be 0.55, 0.69, 0.84, 1, 1.17, 1.35, 1.54, 1.7, 1.8, etc., but is not limited to these.

[0162] Preferably, h2 may be 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.15, 1.2, etc., but is not limited to these.

[0163] In the above solution, if the maximum thickness of the first opening 2111 and the thickness of the first main body 2112 satisfy the above relationship, processing and manufacturing are facilitated, the first opening 2111 has relatively high strength, the space occupied by the first opening 2111 is relatively small, and the battery cell 20 has a relatively high energy density.

[0164] According to some embodiments of the present application, h1 and h2 satisfy at least one of the following conditions: (1) 0.15 ≤ h ≤ 0.3, (2) 0.69 mm ≤ h1 ≤ 1.04 mm, and (3) 0.6 mm ≤ h2 ≤ 0.8 mm.

[0165] Preferably, h may be 0.15, 0.17, 0.19, 0.21, 0.23, 0.25, 0.27, 0.3, etc., but is not limited to these.

[0166] Preferably, h1 may be 0.69 mm, 0.75 mm, 0.79 mm, 0.82 mm, 0.9 mm, 0.94 mm, 1.04 mm, etc., but is not limited to these.

[0167] Preferably, h2 may be 0.6 mm, 0.64 mm, 0.66 mm, 0.68 mm, 0.7 mm, 0.72 mm, 0.74 mm, 0.8 mm, etc., but is not limited to these.

[0168] In the above solution, compared to 0.1≦h≦0.5, 0.55mm≦h1≦1.8mm, and 0.5mm≦h2≦1.2mm, if the values ​​are 0.15≦h≦0.3, 0.69mm≦h1≦1.56mm, and 0.6mm≦h2≦0.8mm, the difficulty of processing and manufacturing is relatively low, the strength of the first opening 2111 is relatively high, and the space occupied by the first opening 2111 is relatively small.

[0169] Referring to Figure 7, which is a schematic diagram of the structure of a first wall according to some embodiments of the present application, the first wall before the shell body and end cap are assembled. According to some embodiments of the present application, the first opening 2111 includes a first segment 2111a and a second segment 2111b connected to each other, the first segment 2111a, the second segment 2111b and the first body 2112 are arranged sequentially along a third direction X, the maximum thickness of the second segment 2111b is greater than the thickness of the first body 2112 and the maximum thickness of the second segment 2111b is greater than the maximum thickness of the first segment 2111a, a first stepped surface 2113 is formed between the second segment 2111b and the first segment 2111a, and the end cap 21b is fitted to the first stepped surface 2113 and connected to the first segment 2111a.

[0170] The first segment 2111a, the second segment 2111b, and the first main body 2112 are arranged sequentially along the third direction X, with the first segment 2111a being closer to the opening than the second segment 2111b, and the first segment 2111a is used to connect to the end cap 21b.

[0171] The maximum thickness of the first segment 2111a may be h3, and the maximum thickness of the second segment 2111b may be h1. In this case, h1 > h3, meaning that the maximum thickness of the second segment 2111b is greater than the maximum thickness of the first segment 2111a. As a result, after the end cap 21b and the first segment 2111a are connected, the first opening 2111 has relatively high strength.

[0172] In some examples, 0.4 mm ≤ h3 ≤ 1.6 mm.

[0173] Preferably, h3 may be 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, etc., but is not limited to these.

[0174] Since the first wall 211 is the narrow surface of the battery cell 20, in the manufacturing process of the battery cell 20, a thinning treatment is usually performed in the region of the first segment 2111a of the shell body 21a, so that the maximum thickness of the region is less than the thickness of the first main body 2112, thereby facilitating the welding of the first wall 211 and the end cap 21b. In some embodiments of the present invention, a thickening treatment can be performed in the region of the first segment 2111a of the shell body 21a before the first segment 2111a and the end cap 21b are connected, so that the maximum thickness of the region of the first segment 2111a of the shell body 21a is greater than or equal to the thickness of the first main body 2112, thereby improving the strength of the connection between the first wall 211 and the end cap 21b. In some other embodiments of the present invention, a thickening treatment can be performed on a region of the first segment 2111a of the shell body 21a before the first segment 2111a and the end cap 21b are connected, and the maximum thickness of the region of the first segment 2111a of the shell body 21a may be less than the thickness of the first main body 2112, thereby improving the strength of the connection between the first wall 211 and the end cap 21b.

[0175] The second segment 2111b is provided adjacent to the first segment 2111a, and at least a portion of the second segment 2111b is a heat-affected area after the end cap 21b and the first segment 2111a have been welded together.

[0176] The maximum thickness of the second segment 2111b is greater than the maximum thickness of the first segment 2111a, and a first stepped surface 2113 is formed between the second segment 2111b and the first segment 2111a. Therefore, in the manufacturing process of the battery cell 20, the end cap 21b can be positioned relative to the end cap 21b by being fitted onto the first stepped surface 2113.

[0177] In the above solution, the first segment 2111a, the second segment 2111b, and the first main body 2112 are arranged sequentially along the third direction X, and the end cap 21b and the first segment 2111a are connected, so that the second segment 2111b is adjacent to the connection point between the end cap 21b and the first segment 2111a, the first opening 2111 has relatively high strength, the risk of the shell body 21a cracking near the welding area of ​​the shell body 21a and the end cap 21b is reduced, and the service life and reliability of the battery cell 20 can be improved.

[0178] Referring to Figure 8, which is a schematic diagram of the structure of a second wall according to some embodiments of the present application. According to some embodiments of the present application, the second wall 212 includes a second opening 2121 and a second body portion 2122 that are sequentially connected in a third direction X, the second body portion 2122 being further from the opening than the second opening 2121, the second opening 2121 being connected to an end cap 21b, and the maximum thickness of the second opening 2121 being greater than the thickness of the second body portion 2122.

[0179] Along the third direction X, the second main body portion 2122 may be further from the opening than the second opening 2121, and may surround the second opening 2121 to form an opening.

[0180] In some embodiments, the end cap 21b may be welded to a portion of the second opening 2121 to form a second welded area, which may be referred to as a weld mark.

[0181] In some embodiments, the second main body portion 2122 may have a uniform thickness structure, and the thickness of the second main body portion 2122 may be the maximum thickness of the second main body portion 2122. The second opening 2121 may have a uniform thickness structure or a differential thickness structure. If the second opening 2121 has a uniform thickness structure, the maximum thickness of the second opening 2121 is the thickness at any position of the second opening 2121. If the second opening 2121 has a differential thickness structure, the maximum thickness of the second opening 2121 may be the thickness at the position where the thickness of the second opening 2121 is maximum.

[0182] Preferably, if the second opening 2121 has a differential thickness structure, the thickness of the second opening 2121 gradually decreases from the end furthest from the second main body 2122 to the end closer to the second main body 2122, and the region where the thickness of the second opening 2121 is maximum may be located at the end furthest from the second main body 2122.

[0183] In the above solution, the strength of the second wall 212 can be increased by thickening the second opening 2121, and in the charge-discharge cycle process of the battery cell 20, the strength of the second opening 2121 is increased, thereby reducing the risk of the shell body 21a cracking near the welded area of ​​the shell body 21a and the end cap 21b.

[0184] In some embodiments, when viewed along the thickness direction of the end cap 21b, the second opening 2121 may partially overlap with the electrode assembly 22, or it may not overlap with the electrode assembly 22.

[0185] According to some embodiments of the present application, the shell body 21a may further include a bottom wall 213, two first walls 211 and two second walls 212 circumferentially provided around the bottom wall 213, the two first walls 211 and the two second walls 212 being integrally molded with the bottom wall 213, and the bottom wall 213 and the end cap 21b being provided opposite each other in a third direction X.

[0186] According to some embodiments of the present invention, the shell body 21a is a prismatic structure having openings at both ends, and there are two end caps 21b, each of which closes two openings.

[0187] If the shell body 21a has a prismatic structure, the battery cell 20 may be a rectangular battery.

[0188] When the positive electrode tab and the negative electrode tab are provided at both ends of the electrode assembly 22, the shell body 21a has two openings, and the positive electrode terminal and the negative electrode terminal can be provided on two end caps 21b respectively, whereby the positive electrode tab and the negative electrode tab can be electrically connected respectively, and thereby, the charge and discharge of the battery cell 20 become easy.

[0189] In the above solution, openings are provided at both ends of the shell body 21a respectively, and by thickening treatment for both of the two openings, the risk of the shell body 21a cracking is reduced.

[0190] According to some embodiments of the present application, the battery cell 20 further includes an electrode assembly 22, the electrode assembly 22 includes a positive electrode sheet, the positive electrode sheet includes a positive electrode active material, the positive electrode active material includes a nickel element-containing compound, the nickel element-containing compound includes a layered lithium-containing transition metal oxide, and the value of the ratio of the molar amount of the nickel element in the layered lithium-containing transition metal oxide to the total molar amount of the transition metal elements in the layered lithium-containing transition metal oxide is 50% or more.

[0191] The content of the nickel element affects the energy density of the battery cell 20, and the higher the content of the nickel element, the higher the energy density of the battery cell 20.

[0192] In the above solution, since the content of the nickel element is relatively high, the battery cell 20 has a relatively high energy density, and the first opening 2111 is relatively thick and has a relatively high strength, the risk of the shell body 21a cracking in the vicinity of the welding region between the shell body 21a and the end cap 21b of the battery cell 20 with a relatively high nickel content can be reduced.

[0193] According to some embodiments of the present application, the layered lithium-containing transition metal oxide is Li a Ni b Co c M d O e A fIt contains, where 0 < a ≤ 1.2, 0.6 ≤ b < 1, 0 < c < 1, 0 < d < 1, 1 ≤ e ≤ 2, 0 ≤ f ≤ 1, M contains one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti, and B, but is not limited thereto, and A contains one or more of N, F, S, and Cl, but is not limited thereto.

[0194] In the above solution, the nickel content is relatively high, the energy density of the battery cell 20 is relatively high, the first opening 2111 has relatively high strength, and the risk of cracking of the shell body 21a near the welding region between the shell body 21a and the end cap 21b of the battery cell 20 with a relatively high nickel content is reduced.

[0195] According to some embodiments of the present application, 0.7 ≤ b ≤ 0.98.

[0196] Preferably, b may be 0.7, 0.72, 0.74, 0.76, 0.78, 0.8, 0.82, 0.84, 0.86, 0.88, 0.9, 0.92, 0.94, 0.96, 0.98, etc., but is not limited thereto.

[0197] In the above solution, the nickel content is relatively high, and the battery cell 20 has a relatively high energy density.

[0198] According to some embodiments of the present application, 0.4 ≤ b / h ≤ 8.1.

[0199] Preferably, b / h may be 0.4, 1.1, 1.8, 2.5, 3.2, 3.9, 4.6, 5, 5.7, 6.4, 7.1, 7.8, 8.1, etc., but is not limited thereto.

[0200] In the above solution, the manufacturing difficulty of the battery cell 20 is relatively low, the battery cell 20 has a relatively high energy density, the thermal runaway and gas generation of the battery cell 20 are relatively few, the first wall 211 has relatively high strength, and the risk of cracking of the first wall 211 due to fatigue is relatively low.

[0201] According to some embodiments of this application, 1 ≤ b / h ≤ 6.

[0202] Preferably, b / h may be 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, etc., but is not limited to these.

[0203] In the above solution, when 1 ≤ b / h ≤ 6 is used, compared to 0.4 ≤ b / h ≤ 8.1, the strength of the first wall 211 is relatively high, the space occupied by the first opening is relatively small, the battery cell 20 has a relatively high energy density, and thermal runaway and gas generation of the battery cell 20 are relatively low.

[0204] Referring to Figure 3, according to some embodiments of the present application, the electrode assembly 22 includes a body portion 221 on which an active material is provided, and the body portion 221 has a first surface 221a facing the end cap 21b. Along the direction from the first body portion 2112 toward the first opening 2111, the first opening 2111 extends beyond the first surface 221a.

[0205] In some embodiments, the electrode assembly 22 may further include tabs 222 extending from the body portion 221, the tabs 222 extending from the first surface 221a.

[0206] When viewed along the thickness direction of the first wall 211, the first opening 2111 does not overlap with the body portion 221.

[0207] In the above solution, the risk of interference between the first opening 2111 and the body portion 221 can be reduced by ensuring that the first opening 2111 extends beyond the first surface 221a in the direction from the first main body portion 2112 toward the first opening 2111.

[0208] According to some embodiments of the present application, the second opening 2121 extends beyond the first surface 221a in the direction from the second main body 2122 toward the second opening 2121.

[0209] When viewed along the thickness direction of the first wall 211, the second opening 2121 does not overlap with the body portion 221.

[0210] In the above solution, the risk of interference between the second opening 2121 and the body portion 221 can be reduced by ensuring that the second opening 2121 extends beyond the first surface 221a in the direction from the second main body portion 2122 toward the second opening 2121.

[0211] Referring to Figure 9, Figure 9 is a cross-sectional view of a part of the structure after the end cap and shell shell have been assembled according to some embodiments of the present application. According to some embodiments of the present application, the shell body 21a and the end cap 21b are welded to form a welded region 210, and the average grain size of the portion of the first opening 2111 excluding the welded region 210 is greater than the average grain size of the first main body portion 2112, and the average grain size is the average grain size in the thickness direction of the first wall 211 of the crystal grains.

[0212] The welding region 210 is the region formed by welding the shell body 21a and the end cap 21b, and in some embodiments, the welding region 210 may be referred to as the weld mark.

[0213] The thickness direction of the first wall 211 may be parallel to the Z direction.

[0214] For standards regarding the testing method for average grain size, please refer to the following: GB / T 6394-2017 "Method for Measuring Average Grain Size of Metals" and GB / T 13298-2017 "Electron Back-View Microscopy Method for Measuring Grain Size of Metallic Materials".

[0215] In the above solution, the average grain size of the portion of the first opening 2111 excluding the welding area 210 is larger than the average grain size of the first main body portion 2112, which is advantageous for strengthening the first opening 2111. As a result, the first opening 2111 has relatively high strength, and the risk of the shell body 21a cracking near the welding area 210 of the shell body 21a and the end cap 21b is reduced.

[0216] According to some embodiments of the present application, in a cross-section of the first wall 211 parallel to the thickness direction of the first wall 211, the portion located below the welding area 210 of the first opening 2111 has 15 or more crystal grains in the width direction of the cross-section.

[0217] The width direction of the cross-section may be parallel to the Z direction.

[0218] "The portion located below the welding area 210 of the first opening 2111" refers to the portion located below the welding area 210 of the first opening 2111 in the direction from the first opening 2111 towards the first main body 2112 in the X direction in Figure 9, that is, the portion that is far from the welding area 210 of the first opening 2111 along the direction from the first opening 2111 towards the first main body 2112.

[0219] In the above solution, having 15 or more crystal grains in the width direction of the cross-section is advantageous for strengthening the first opening 2111, thereby giving the first opening 2111 relatively high strength.

[0220] According to some embodiments of the present application, the average grain size range of the portion of the first opening 2111 excluding the welding area 210 is 70 μm to 1200 μm, and / or the average grain size range of the first body portion 2112 is 30 μm to 1000 μm.

[0221] Preferably, the average grain size of the portion of the first opening 2111 excluding the welded area 210 may be 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., but is not limited to these.

[0222] Preferably, the average crystal grain size of the first main body portion 2112 may be 30 μm, 40 μm, 50 μm, 60 μm, 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, etc., but is not limited to these.

[0223] In the above solution, if the average crystal grain size of the first opening 2111 and / or the average crystal grain size of the first main body 2112 satisfy the above relationship, it is advantageous for strengthening the strength of the first opening 2111, thereby giving the first opening 2111 relatively high strength.

[0224] According to some embodiments of the present application, the average grain size of the portion of the second opening 2121 excluding the welded area 210 is greater than the average grain size of the second main body portion 2122, and the average grain size is the average grain size in the thickness direction of the second wall 212 of the crystal grain.

[0225] In the above solution, the average grain size of the portion of the second opening 2121 excluding the welding area 210 is larger than the average grain size of the second main body portion 2122, which is advantageous for strengthening the second opening 2121. As a result, the second opening 2121 has relatively high strength, and the risk of the shell body 21a cracking near the welding area 210 of the shell body 21a and the end cap 21b is reduced.

[0226] According to some embodiments of the present application, in a cross-section of the second wall 212 parallel to the thickness direction of the second wall 212, the portion located below the welding area 210 of the second opening 2121 has 15 or more crystal grains in the width direction of the cross-section.

[0227] The width direction of the cross-section is parallel to the Y direction.

[0228] "The portion located below the welding area 210 of the second opening 2121" refers to the portion located below the welding area 210 of the second opening 2121 in the direction from the second opening 2121 toward the second main body 2122 in the X direction, that is, the portion that is far from the welding area 210 of the second opening 2121 along the direction from the second opening 2121 toward the second main body 2122.

[0229] In the above solution, having 15 or more crystal grains in the width direction of the cross-section is advantageous for strengthening the second opening 2121, thereby giving the second opening 2121 relatively high strength.

[0230] According to some embodiments of the present application, the average grain size range of the portion of the second opening 2121 excluding the welding area 210 is 70 μm to 1200 μm, and / or the average grain size range of the second main body portion 2122 is 30 μm to 1000 μm.

[0231] Preferably, the average grain size of the portion of the second opening 2121 excluding the welded area 210 may be 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., but is not limited to these.

[0232] Preferably, the average grain size of the second main body portion 2122 may be 30 μm, 40 μm, 50 μm, 60 μm, 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, etc., but is not limited to these.

[0233] In the above solution, if the average crystal grain size of the second opening 2121 and / or the average crystal grain size of the second main body 2122 satisfies the above relationship, it is advantageous for strengthening the strength of the second opening 2121, thereby giving the second opening 2121 relatively high strength.

[0234] The following describes the structure and test data of the battery cell 20 in a specific example.

[0235] Example 1 In the manufacture of the battery cell 20, the welding method between the end cap 21b and the shell body 21a is laser welding, and the material of the shell body 21a is aluminum. The length of the battery cell 20 (size W2 in the first direction Z of the shell body 21a) is 220 mm, the width of the battery cell 20 (size W1 in the second direction Y of the shell body 21a) is 44 mm, W is 0.2, the thickness h2 of the first main body 2112 is 0.5 mm, the thickness ratio h of the first opening 2111 is 0.15, h / W is 0.75, the nickel content b is 0.95, and b / h is 6.3.

[0236] Example 2 Compared to Example 1, h is 0.2 and h / W is 1.

[0237] Example 3 Compared to Example 1, h is 0.5 and h / W is 2.5.

[0238] Example 4 Compared to Example 1, the width of the battery cell 20 is 55 mm, W is 0.25, h is 0.3, and h / W is 1.2.

[0239] Example 5 Compared to Example 1, the width of the battery cell 20 is 77 mm, W is 0.35, h is 0.275, and h / W is 0.79.

[0240] Example 6 Compared to Example 1, the width of the battery cell 20 is 90 mm, the length of the battery cell 20 is 180 mm, W is 0.5, h is 0.275, and h / W is 0.55.

[0241] Example 7 Compared with Example 1, the width of the battery cell 20 is 70 mm, the length of the battery cell 20 is 148 mm, W is 0.47, h is 0.5, and h / W is 1.06.

[0242] Example 8 Compared with Example 1, the width of the battery cell 20 is 70 mm, the length of the battery cell 20 is 148 mm, W is 0.47, h is 0.25, and h / W is 0.53.

[0243] Example 9 Compared with Example 1, the width of the battery cell 20 is 88.5 mm, the length of the battery cell 20 is 148 mm, W is 0.6, h is 0.35, and h / W is 0.58.

[0244] Comparative Example 1 Compared with Example 1, the width of the battery cell 20 is 33 mm, the length of the battery cell 20 is 220 mm, W is 0.15, h is 0.15, and h / W is 1.

[0245] Comparative Example 2 Compared with Example 1, the width of the battery cell 20 is 44 mm, the length of the battery cell 20 is 220 mm, W is 0.2, h is 0.1, and h / W is 0.5.

[0246] Comparative Example 3 Compared with Example 1, the width of the battery cell 20 is 70 mm, the length of the battery cell 20 is 148 mm, W is 0.47, h is 0.2, and h / W is 0.42.

[0247] A short-circuit test was conducted on the battery cell 20 in Examples 1 to 8 and Comparative Examples 1 to 3. The test method referred to GBT31485-2015 as follows, and the test results are shown in Table 1.

[0248] The test is conducted in an environment with a temperature of 25°C ± 5°C, relative humidity of 15% to 90%, and atmospheric pressure of 86kPa to 106kPa. The battery cell 20 is charged with a constant current of 1I1(A) until it reaches the charging termination voltage specified in the company's technical conditions. Then, constant voltage charging is performed, and charging is stopped until the charging current drops to 0.05I1(A). After charging, the battery cell 20 is left for 1 hour, and a short-circuit test is performed on the battery cell 20. To determine the short-circuit type, the positive and negative electrodes of the battery cell 20 are short-circuited externally until the battery cell 20 experiences thermal runaway. The external circuit resistance is set to be less than 5mΩ, and the integrity of the shell body 21a is observed when the battery cell 20 experiences thermal runaway.

[0249] [Table 1]

[0250] As can be seen from the comparison of the results of Examples 1-8 and Comparative Example 1 in Table 1, if W is too small, the second wall 212 of the shell body 21a is prone to cracking.

[0251] As can be seen from the comparison of the results of Examples 1-8 and Comparative Examples 2-3 in Table 1, if h / W is too small, the first wall 211 of the shell body 21a is prone to cracking. Thickening the first opening 2111 of the first wall 211 reduces the risk of the first wall 211 cracking, and thus reduces the risk of the shell body 21a cracking.

[0252] According to some embodiments of the present application, the embodiments of the present application provide a battery 100 including a battery cell 20 according to any one of the above embodiments.

[0253] Referring to Figures 10 and 11, Figure 10 is a schematic diagram of the assembly of an end plate and a plurality of battery cells according to some embodiments of the present application, and Figure 11 is a schematic diagram of the assembly of an end plate and battery cells at the end according to some embodiments of the present application. According to some embodiments of the present application, the number of battery cells 20 is plurality, and the plurality of battery cells 20 are stacked along a second direction Y, and the battery 100 further includes an end plate 30, which is provided at the end of the plurality of battery cells 20 along the second direction Y.

[0254] In some embodiments, along the direction from the first main body portion 2112 toward the first opening 2111, at least a portion of the first opening 2111 extends beyond the end plate 30.

[0255] Multiple battery cells 20 are stacked along a second direction Y, and end plates 30 are provided at the ends of the multiple battery cells 20 along the second direction Y. The end plates 30 are connected to the battery cells 20 located at the ends of the multiple battery cells 20 in the second direction Y, and the end plates 30 can restrict the deformation of the battery cells 20 by restricting the position of the battery cells 20 at those ends.

[0256] In the above solution, the end plates 30 are provided at the ends of multiple battery cells 20 in the second direction Y, and the end plates 30 and the shell bodies 21a of adjacent battery cells 20 have a relatively large connection area, thereby creating a constraint on the shell bodies 21a and reducing the risk of the shell bodies 21a cracking due to fatigue.

[0257] According to some embodiments of the present application, the end plate 30 is provided facing the second wall 212.

[0258] In the above solution, since the end plate 30 is provided facing the second wall 212, the end plate 30 and the second wall 212 have a relatively large connection area, and in the charge-discharge cycle process of the battery cell 20, the end plate 30 restricts the second wall 212, thereby reducing the risk of the shell body 21a cracking near the welding area of ​​the shell body 21a and the end cap 21b.

[0259] According to some embodiments of the present application, the embodiments of the present application provide a power consumption device including a battery cell 20 or battery according to any one of the above embodiments.

[0260] The power-consuming equipment may be a system or device to which any one of the above-mentioned battery cells 20 or battery 100 is applied, and the battery cell 20 or battery 100 is used to supply electrical energy.

[0261] According to some embodiments of the present application, the embodiments of the present application provide an energy storage device including a battery cell 20 or battery 100 according to any one of the above embodiments.

[0262] According to some embodiments of the present application, referring to Figures 3 to 8, embodiments of the present application provide a battery cell 20 exhibiting a rectangular parallelepiped shape. The battery cell 20 includes a shell 21, an electrode assembly 22, and electrode terminals 23, wherein the electrode assembly 22 is provided within the shell 21, the shell 21 includes a shell body 21a and an end cap 21b, the electrode terminals 23 are provided on the end cap 21b, and the electrode terminals 23 are connected to tabs of the electrode assembly 22. The shell body 21a has an opening and includes two first walls 211 facing each other along a first direction Z, two second walls 212 facing each other along a second direction Y, and a bottom wall 213. The two first walls 211 and the two second walls 212 are circumferentially positioned around the bottom wall 213, and the two first walls 211 and the two second walls 212 are integrally molded with the bottom wall 213. The bottom wall 213 and the end cap 21b are positioned facing each other in a third direction X, and the end cap 21b closes the opening by connecting with the first walls 211 and the second walls 212.

[0263] The outer surface area of ​​the first wall 211 is smaller than the outer surface area of ​​the second wall 212, the first wall 211 includes a first opening 2111 and a first body portion 2112 arranged sequentially along a third direction X, the third direction X is parallel to the thickness direction of the end cap 21b, the first body portion 2112 is further from the opening than the first opening 2111, the end cap 21b is connected to the first wall 211 and the second wall 212 to close the opening, if the size of the first wall 211 in the second direction Y is W1 and the size of the second wall 212 in the first direction Z is W2, then the condition 0.2 ≤ W1 / W2 ≤ 0.5 is satisfied, and the thickness of the first opening 2111 is greater than the thickness of the first body portion 2112. If the maximum thickness of the first opening 2111 is h1 and the thickness of the first main body 2112 is h2, then the following conditions are satisfied: 0.55 ≤ h / W ≤ 2.5, h = (h1 - h2) / h2, and W = W1 / W2. The maximum thickness of the first opening 2111 is h1, and the thickness of the first main body 2112 is h2.

[0264] According to the battery cell 20 of the embodiment of the present application, when the maximum thickness of the first opening 2111, the thickness of the first main body portion 2112, the size of the first wall 211 in the second direction Y, the size of the second wall 212 in the first direction Z, and the area of the outer surface of the first wall 211 satisfy the above relationship, by thickening the first opening 2111, the first opening 2111 has relatively high strength, and the risk that the first wall 211 cracks due to fatigue in the charge-discharge cycle process of the battery cell 20 can be reduced. At the same time, the processing and manufacturing of the first opening 2111 are facilitated, the space occupied by the first opening 2111 is relatively small, and the battery cell 20 has a relatively high energy density.

[0265] The present application has been described with reference to preferred embodiments, but various improvements can be made without departing from the scope of the present application, and the members therein can be replaced with equivalents. In particular, each technical feature described in each embodiment can be arbitrarily combined as long as there is no structural contradiction. The present application is not limited to the specific embodiments disclosed in this specification, but includes all technical solutions included in the scope of the claims.

Claims

1. A shell body and an end cap are included, wherein the shell body has an opening, and the shell body includes two first walls facing each other along a first direction and two second walls facing each other along a second direction, the area of ​​the outer surface of the first walls being smaller than the area of ​​the outer surface of the second walls, and the first walls include a first opening and a first main body portion arranged sequentially along a third direction, the third direction being parallel to the thickness direction of the end cap, the first main body portion being further from the opening than the first opening, and the end cap includes a shell that is connected to the first and second walls and closes the opening. The size of the first wall in the second direction is W. １ Let W be the size of the second wall in the first direction. ２ In that case, 0.2 ≤ W １ / W ２ The following conditions are met: the maximum thickness of the first opening is greater than the thickness of the first main body, and the second, third, and first directions are perpendicular to each other in pairs. Battery cell.

2. W １ / W ２ ≤ 0.6 The battery cell according to claim 1.

3. 0.25 ≤ W １ / W ２ ≤ 0.35 The battery cell according to claim 1 or 2.

4. 50 mm ≤ W １ ≤ 90 mm, preferably, 60 mm ≤ W １ ≤ 86 mm The battery cell according to claim 3.

5. Let the maximum thickness of the first opening be h1, and the thickness of the first main body be h ２ In this case, 0.55 ≤ h / W ≤ 2.5, h = (h １ -h ２ ) / h ２ W = W １ / W ２ To satisfy the following A battery cell according to any one of claims 1 to 4.

6. 0.6 ≤ h / W ≤ 1.8 The battery cell according to claim 5.

7. The maximum thickness of the first opening is h １ The thickness of the first main body is h ２ If the area of ​​the outer surface of the first wall is S, then (1 / 360000) mm －２ ≦h / S≦(1 / 9000)mm －２ h = (h １ -h ２ ) / h ２ To satisfy the following A battery cell according to any one of claims 1 to 6.

8. (1 / 300000)mm －２ ≦h / S≦(1 / 15000)mm －２ That is, The battery cell according to claim 7.

9. 4500mm ２ ≤S ≤ 36000mm ２ That is, The battery cell according to claim 7 or 8.

10. 6000mm ２ ≤S ≤ 22500mm ２ That is, The battery cell according to claim 9.

11. The maximum thickness of the first opening is h １ The thickness of the first main body is h ２ In that case, h = (h １ -h ２ ) / h ２ h １ , h ２ teeth, (1) 0.1 ≤ h ≤ 0.5, (2)0.55mm≦h １ ≦1.8mm、 (3) 0.5 mm ≤ h ２ Satisfying at least one of the following conditions, such as ≤1.2 mm A battery cell according to any one of claims 1 to 10.

12. h １ , h ２ teeth, (1) 0.15 ≤ h ≤ 0.3, (2) 0.69#F] １ ≦1.043-1 (3) 0.6 mm ≤ h ２ Satisfying at least one of the following conditions, such as ≤0.8 mm The battery cell according to claim 11.

13. The first opening includes a first segment and a second segment connected to each other, the first segment, the second segment and the first body are arranged sequentially along the third direction, the maximum thickness of the second segment is greater than the thickness of the first body, the maximum thickness of the second segment is greater than the maximum thickness of the first segment, a first stepped surface is formed between the second segment and the first segment, and the end cap is fitted to the first stepped surface and connected to the first segment. A battery cell according to any one of claims 1 to 12.

14. The second wall includes a second opening and a second body portion that are sequentially connected in the third direction, the second body portion being further from the opening than the second opening, the second opening being connected to the end cap, and the maximum thickness of the second opening being greater than the thickness of the second body portion. A battery cell according to any one of claims 1 to 13.

15. The shell body has a prismatic structure with openings at both ends, and there are two end caps, each of which closes one of the two openings. A battery cell according to any one of claims 1 to 14.

16. The battery cell further includes an electrode assembly, the electrode assembly includes a positive electrode sheet, the positive electrode sheet includes a positive electrode active material, the positive electrode active material includes a nickel element-containing compound, the nickel element-containing compound includes a layered lithium-containing transition metal oxide, and the ratio of the molar amount of nickel element in the layered lithium-containing transition metal oxide to the total molar amount of transition metal elements in the layered lithium-containing transition metal oxide is 50% or more. A battery cell according to any one of claims 1 to 15.

17. The aforementioned layered lithium-containing transition metal oxide is Li ａ Ni ｂ Co ｃ M ｄ O ｅ A ｆ It includes, where 0 < a ≤ 1.2, 0.6 ≤ b < 1, 0 < c < 1, 0 < d < 1, 1 ≤ e ≤ 2, 0 ≤ f ≤ 1, and M includes, but is not limited to, one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti, and B, and A includes, but is not limited to, one or more of N, F, S, and Cl. The battery cell according to claim 16.

18. 0.7 ≤ b ≤ 0.98 The battery cell according to claim 17.

19. 0.4 ≤ b / h ≤ 8.1 The battery cell according to claim 17 or 18.

20. 1 ≤ b / h ≤ 6 The battery cell according to claim 19.

21. The battery cell further includes an electrode assembly, the electrode assembly includes a body, the body is provided with an active material, the body has a first surface facing the end cap, and the first opening extends beyond the first surface in a direction from the first body toward the first opening. A battery cell according to any one of claims 1 to 20.

22. The shell body and the end cap are welded together to form a welded region, the average grain size of the portion of the first opening excluding the welded region is greater than the average grain size of the first main body, and the average grain size is the average grain size of the crystal grains in the thickness direction. A battery cell according to any one of claims 1 to 21.

23. In the cross-section of the first wall parallel to the thickness direction of the first wall, the portion of the first opening located below the welding area has 15 or more crystal grains in the width direction of the cross-section. The battery cell according to claim 22.

24. The average grain size range of the portion of the first opening excluding the welding area is 70 microns to 1200 microns, and / or the average grain size range of the first main body is 30 microns to 1000 microns. The battery cell according to claim 22 or 23.

25. Includes a battery cell according to any one of claims 1 to 24, battery.

26. The number of the battery cells is multiple, and the multiple battery cells are arranged in a stack along the second direction, and the battery further includes end plates, which are provided at the ends of the multiple battery cells along the second direction. The battery according to claim 25.

27. The end plate is provided facing the second wall, The battery according to claim 26.

28. A battery cell according to any one of claims 1 to 24 or a battery according to any one of claims 25 to 27, wherein the battery cell or the battery is used to supply electrical energy. Power consuming equipment.

29. A battery comprising a battery cell according to any one of claims 1 to 24 or a battery according to any one of claims 25 to 27, Energy storage device.

Images