Battery cell, battery, and electric device

Abstract

The present application provides a battery cell, a battery, and an electric device. The battery cell comprises an electrode assembly, a casing, a first end cover, and a second end cover; the casing has a first opening and a second opening; the first opening and the second opening are respectively located at two ends of the casing in a first direction; the casing comprises a main body portion, a first thickened portion, and a second thickened portion; the main body portion surrounds the electrode assembly; the first thickened portion is connected to the main body portion and is arranged in the circumferential direction of the first opening; the second thickened portion is connected to the main body portion and is arranged in the circumferential direction of the second opening; the thickness of the first thickened portion is greater than the thickness of the main body portion; and the thickness of the second thickened portion is greater than the thickness of the main body portion. The first end cover is connected to the first thickened portion and covers the first opening. The second end cover is connected to the second thickened portion and covers the second opening.

Description

Battery cells, batteries and electrical devices

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202421498884.3, filed on June 27, 2024, entitled “Battery Cell, Battery and Electrical Device”, the entire contents of which are incorporated herein by reference. Technical Field

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

[0004] With the development of new energy technologies, batteries are being used more and more widely, for example in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0005] In the development of battery technology, the reliability of individual battery cells directly affects the reliability, cost of use, and user experience of end products. Therefore, how to effectively improve the reliability of individual battery cells is a pressing technical problem that needs to be solved in battery technology.

[0006] Summary of the Invention

[0007] In view of the above problems, this application provides a battery cell, a battery, and an electrical device that can effectively improve the reliability of the battery cell.

[0008] In a first aspect, embodiments of this application provide a battery cell, which includes an electrode assembly, a housing, a first end cap, and a second end cap. The housing has a first opening and a second opening, which are respectively located at opposite ends of the housing along a first direction. The housing includes a main body, a first thickened portion, and a second thickened portion. The main body surrounds the electrode assembly. The first thickened portion is connected to the main body and is circumferentially arranged along the first opening. The second thickened portion is connected to the main body and is circumferentially arranged along the second opening. The thickness of the first thickened portion is greater than the thickness of the main body, and the thickness of the second thickened portion is greater than the thickness of the main body. The first end cap is connected to the first thickened portion and covers the first opening. The second end cap is connected to the second thickened portion and covers the second opening.

[0009] The above technical solution provides a relatively thick first thickened portion along the circumference of the first opening on the housing, and connects the first end cap to the first thickened portion. The thicker first thickened portion has higher structural strength, thereby improving the structural strength of the first end cap after it is fitted to the housing, and reducing the risk of cracking and failure at the connection point. Similarly, by providing a relatively thick second thickened portion along the circumference of the second opening on the housing, and connecting the second end cap to the second thickened portion, the thicker second thickened portion has even higher structural strength, thereby improving the structural strength of the second end cap after it is fitted to the housing, and reducing the risk of cracking and failure at the connection point. This effectively improves the reliability of the battery cell.

[0010] In some embodiments of the first aspect, the first thickened portion protrudes relative to the inner surface of the main body portion.

[0011] The inner surface of the main body is the side of the main body facing the electrode assembly, and the first thickened portion protrudes towards the interior of the housing. When the thickness of the first thickened portion is constant, the first thickened portion protruding from the inner surface of the main body can reduce the occupancy rate of the first thickened portion on the outer space of the housing, thereby reducing the maximum size of the housing, making full use of the internal space of the housing, and helping to improve the energy density of the battery cell.

[0012] In some embodiments of the first aspect, the first thickened portion protrudes relative to the outer surface of the main body portion.

[0013] The outer surface of the main body is the surface of the main body that faces away from the electrode assembly, and the first thickened portion protrudes outward toward the outer side of the housing. When the thickness of the first thickened portion is constant, the first thickened portion protrudes from the outer surface of the main body, which can reduce the occupancy rate of the first thickened portion on the internal space of the housing, thereby reducing the risk of interference between the first thickened portion and the electrode assembly, and helping to further improve the reliability of the battery cell.

[0014] In some embodiments of the first aspect, the second thickened portion protrudes relative to the inner surface of the main body portion.

[0015] The inner surface of the main body is the side of the main body facing the electrode assembly, and the second thickened portion protrudes inward toward the interior of the housing. When the thickness of the second thickened portion is constant, its protrusion onto the inner surface of the main body reduces its occupancy of the outer space of the housing, thereby reducing the maximum size of the housing and making full use of the internal space, which is beneficial for improving the energy density of the battery cell.

[0016] In some embodiments of the first aspect, the second thickened portion protrudes relative to the outer surface of the main body portion.

[0017] The outer surface of the main body is the surface of the main body that faces away from the electrode assembly, and the second thickened portion protrudes outward toward the outer side of the housing. When the thickness of the second thickened portion is constant, the fact that the second thickened portion protrudes from the outer surface of the main body can reduce the occupancy rate of the second thickened portion on the internal space of the housing, thereby reducing the risk of interference between the second thickened portion and the electrode assembly, which is beneficial to further improving the reliability of the battery cell.

[0018] In some embodiments of the first aspect, the first thickened portion is disposed around the first opening.

[0019] This can further improve the structural strength after the first end cap and the casing are fitted together, thereby further improving the energy density of the battery cell.

[0020] In some embodiments of the first aspect, the second thickened portion is disposed around the second opening.

[0021] This can further improve the structural strength of the second end cap after it is fitted with the casing, thereby further improving the energy density of the battery cell.

[0022] In some embodiments of the first aspect, in a first direction, the first thickened portion extends beyond the first end cap near the end of the electrode assembly.

[0023] This can further ensure and improve the strength of the first end cap after it is fitted with the housing, thereby further improving the reliability of the battery cell.

[0024] In some embodiments of the first aspect, in the first direction, the second thickened portion extends beyond the second end cap at one end near the electrode assembly.

[0025] This can further ensure and improve the strength of the second end cap after it is fitted with the housing, thereby further improving the reliability of the battery cell.

[0026] In some embodiments of the first aspect, the electrode assembly includes a first electrode plate, the first electrode plate including a first coating area and a first tab extending from an end of the first coating area along a first direction. A first thickened portion protrudes relative to the inner surface of the body portion, and the first coating area and the first thickened portion do not overlap in a direction perpendicular to the first direction.

[0027] When the first thickened portion protrudes from the inner surface of the main body, the first coating area and the first thickened portion do not overlap in the direction perpendicular to the first direction. This reduces the risk of interference between the first thickened portion and the first coating area affecting the electrical performance of the electrode assembly. As a result, the maximum size of the housing can be reduced, the internal space of the housing can be fully utilized to improve the energy density of the battery cell, and the adverse effects of the first thickened portion on the electrode assembly can be reduced.

[0028] In some embodiments of the first aspect, the electrode assembly further includes a spacer that covers the first coating area and does not overlap with the first thickened portion in a direction perpendicular to the first direction.

[0029] When the first thickened portion protrudes from the inner surface of the main body, the separator and the first thickened portion do not overlap in the direction perpendicular to the first direction. This reduces the risk of insulation failure between the first electrode and the second electrode due to interference between the first thickened portion and the separator. As a result, the maximum size of the housing can be reduced, the internal space of the housing can be fully utilized to improve the energy density of the battery cell, and the adverse effects of the first thickened portion on the electrode assembly can be further reduced.

[0030] In some embodiments of the first aspect, the electrode assembly has a flat region comprising a plurality of electrodes stacked along a second direction, the first direction intersecting the second direction.

[0031] The above technical solution can reduce the impact of the expansion of the electrode assembly itself on the first end cover and the second end cover, thereby further reducing the risk of cracking and failure at the connection between the first end cover and the housing, and further reducing the risk of cracking and failure at the connection between the second end cover and the housing.

[0032] In some embodiments of the first aspect, the battery cell further includes a support connecting the first end cap and the electrode assembly. The first thickened portion has a larger dimension in the first direction than the second thickened portion in the first direction.

[0033] A bracket is provided between the first end cap and the electrode assembly, which also allows the first end cap and the electrode assembly to have a large space in the first direction, thereby increasing the size range of the first thickened part in the first direction. Thus, the above technical solution can further improve the strength of the first end cap after it is fitted with the shell by increasing the size of the first thickened part in the first direction.

[0034] In some embodiments of the first aspect, the first end cap includes a first cap body and a first extension, the first extension being connected to the first cap body and protruding from the side surface of the first cap body near the housing, at least a portion of the first extension being located inside the housing and connected to a first thickening portion, and the first cap body being located outside the housing and connected to the first thickening portion.

[0035] The introduction of the first extension increases the overall contact area between the first end cap and the first thickened portion, thereby further improving the connection strength between the first end cap and the housing.

[0036] In some embodiments of the first aspect, the second end cap includes a second cap body and a second extension, the second extension being connected to the second cap body and protruding from the side surface of the second cap body near the housing, at least a portion of the second extension being located inside the housing and connected to a second thickened portion, and the second cap body being located outside the housing and connected to the second thickened portion.

[0037] The introduction of the second extension increases the overall contact area between the second end cap and the second thickened portion, thereby further improving the connection strength between the second end cap and the housing.

[0038] In some embodiments of the first aspect, the battery cell further includes a pressure relief mechanism, and the housing includes two opposing first side plates, with the pressure relief mechanism disposed on one of the two first side plates.

[0039] Compared to the first end cap and the second end cap, the first side plate has a larger area. Therefore, placing the pressure relief mechanism on the first side plate can reduce the difficulty of setting up the pressure relief mechanism.

[0040] In some embodiments of the first aspect, the other of the two first side plates is provided with a weld.

[0041] By placing the weld on the first side plate of the two first side plates that does not have a pressure relief mechanism, the impact of the weld on the pressure relief mechanism can be reduced, thereby improving the reliability of the pressure relief mechanism.

[0042] In some embodiments of the first aspect, the main body and the first thickened part are integrally formed.

[0043] On the one hand, the manufacturing process is simplified because there is no need to connect the main body and the first thickened part through an additional connection process. On the other hand, compared with connecting the main body and the first thickened part through an additional connection process, the one-piece structure of the main body and the first thickened part has a higher connection strength.

[0044] In some embodiments of the first aspect, the main body and the second thickened part are integrally formed structures.

[0045] On the one hand, the manufacturing process is simplified by eliminating the need for additional joining processes to connect the main body and the second thickened part. On the other hand, compared to joining the main body and the second thickened part through additional joining processes, the one-piece structure of the main body and the second thickened part provides a higher degree of connection strength.

[0046] In some embodiments of the first aspect, the first end cap is welded to the housing. The welding process is highly reliable, convenient, quick, and cost-effective.

[0047] In some embodiments of the first aspect, the second end cap is welded to the housing. The welding process is highly reliable, convenient, quick, and cost-effective.

[0048] Secondly, this application provides a battery comprising the battery cell provided in any embodiment of the first aspect.

[0049] In some embodiments of the second aspect, a plurality of battery cells are sequentially attached along a second direction, a first thickened portion protrudes from the inner surface of the main body, a second thickened portion protrudes from the inner surface of the main body, and the first direction and the second direction intersect.

[0050] When multiple battery cells are sequentially bonded together along the second direction, the first thickened portion protrudes from the inner surface of the main body, and the second thickened portion protrudes from the inner surface of the main body. This prevents the first and second thickened portions from causing gaps between adjacent battery cells, thereby improving the structural compactness of the battery and thus helping to increase the overall energy density of the battery.

[0051] In some embodiments of the second aspect, a plurality of battery cells are spaced apart along a second direction, a first thickened portion protrudes relative to the outer surface of the main body portion, a second thickened portion protrudes relative to the outer surface of the main body portion, and the first and second directions intersect. The battery cell also includes a separating member disposed between the main bodies of two adjacent battery cells, and in the second direction, the separating member does not overlap with the first thickened portion, nor with the second thickened portion.

[0052] The above-described technical solution, by placing the separator between the main bodies of two adjacent battery cells, can, on the one hand, fully utilize the accommodating space formed by the first and second thickened portions of the two adjacent battery cells, thereby improving the battery's space utilization rate, making the battery structure more compact and reliable, and contributing to increased energy density. On the other hand, the first and second thickened portions can restrict the displacement of the separator, improving battery reliability. Furthermore, in the second direction, the separator does not overlap with either the first or second thickened portion, reducing the risk of interference between the first and second thickened portions and causing damage to the separator.

[0053] Thirdly, this application provides an electrical device that includes a battery provided in any embodiment of the first aspect, the battery being used to provide electrical energy.

[0054] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0055] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0056] Figure 1 is a schematic diagram of the vehicle structure provided in some embodiments of this application;

[0057] Figure 2 is a schematic diagram of the exploded structure of a battery provided in some embodiments of this application;

[0058] Figure 3 is a schematic diagram of the structure of a battery module provided in some embodiments of this application;

[0059] Figure 4 is a three-dimensional structural diagram of a battery cell provided in some embodiments of this application;

[0060] Figure 5 is a schematic diagram of the exploded structure of the battery cell shown in Figure 4;

[0061] Figure 6 is a side view of the battery cell shown in Figure 4.

[0062] Figure 7 is a schematic diagram of the cross-sectional structure along AA in Figure 6;

[0063] Figure 8 is a partial enlarged structural diagram of point F in Figure 7;

[0064] Figure 9 is a partial enlarged structural diagram of point H in Figure 7;

[0065] Figure 10 is a front view structural diagram of another battery cell provided in some embodiments of this application;

[0066] Figure 11 is a partial enlarged structural diagram of point G in Figure 10;

[0067] Figure 12 is a partial enlarged structural diagram of point K in Figure 10;

[0068] Figure 13 is a partial structural schematic diagram of a battery provided in some embodiments of this application;

[0069] Figure 14 is a partial enlarged structural diagram of point M in Figure 13;

[0070] Figure 15 is a magnified schematic diagram of the structure at point N in Figure 13.

[0071] The reference numerals in the detailed embodiments are as follows:

[0072] 1. Vehicle; 2. Battery; 3. Controller; 4. Motor; 5. Housing; 5a. First housing section; 5b. Second housing section; 5c. Storage space; 6. Battery module; 7. Battery cell;

[0073] 10. Electrode assembly; 20. Housing; 21a. First opening; 21b. Second opening; 22. Main body; 23a. First thickened part; 23b. Second thickened part; 24. First side plate; 30a. First end cap; 30b. Second end cap; 31. First cap body; 32. First extension; 33. Second cap body; 34. Second extension; 40. Bracket; 50. Pressure relief mechanism; 60. Separating component; X, first direction; Y, second direction. Detailed Implementation

[0074] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0075] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, rather than to describe a specific order or hierarchy.

[0076] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0077] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0078] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0079] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0080] In this application, "multiple" means two or more (including two).

[0081] In this application, the term "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0082] In this embodiment of the application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0083] The battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., but the embodiments of this application are not limited to this.

[0084] A single battery cell typically includes an electrode assembly. The electrode assembly consists of a positive electrode and a negative electrode. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes.

[0085] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes, which can prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0086] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a layer of positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0087] In some embodiments, the negative electrode may be a negative electrode sheet, which may include a negative electrode current collector and a layer of negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0088] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0089] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0090] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0091] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0092] Gel electrolytes consist of a polymer-based electrolyte backbone network combined with an ionic liquid—lithium salt.

[0093] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0094] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0095] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0096] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0097] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0098] In some implementations, the electrode assembly is a stacked structure.

[0099] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0100] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0101] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0102] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0103] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0104] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0105] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0106] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0107] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0108] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0109] In some embodiments, the battery can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0110] In some embodiments, the battery can be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing.

[0111] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0112] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0113] With the development of new energy technologies, batteries are being used more and more widely, for example in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0114] In the development of battery technology, the reliability of individual battery cells directly impacts the reliability, cost of use, and user experience of end products. After the end cap of a battery cell is welded to the casing, a heat-affected zone (HAZ) often forms near the molten pool. This HAZ is subjected to residual thermal stress, resulting in lower strength compared to other areas. During the use of the battery cell, when the HAZ is subjected to pressure or vibration, the casing is prone to cracking in the HAZ, leading to electrolyte leakage and ultimately battery cell failure, severely affecting the reliability of the battery cell.

[0115] Based on the above considerations, this application provides a battery cell comprising an electrode assembly, a housing, a first end cap, and a second end cap. The housing has a first opening and a second opening, located at opposite ends of the housing along a first direction. The housing includes a main body, a first thickened portion, and a second thickened portion. The main body surrounds the electrode assembly. The first thickened portion is connected to the main body and circumferentially arranged along the first opening. The second thickened portion is connected to the main body and circumferentially arranged along the second opening. The thickness of the first thickened portion is greater than the thickness of the main body, and the thickness of the second thickened portion is greater than the thickness of the main body. The first end cap is connected to the first thickened portion and covers the first opening. The second end cap is connected to the second thickened portion and covers the second opening.

[0116] The above technical solution provides a relatively thick first thickened portion along the circumference of the first opening on the housing, and connects the first end cap to the first thickened portion. The thicker first thickened portion has higher structural strength, thereby improving the structural strength of the first end cap after it is fitted to the housing, and reducing the risk of cracking and failure at the connection point. Similarly, by providing a relatively thick second thickened portion along the circumference of the second opening on the housing, and connecting the second end cap to the second thickened portion, the thicker second thickened portion has even higher structural strength, thereby improving the structural strength of the second end cap after it is fitted to the housing, and reducing the risk of cracking and failure at the connection point. This effectively improves the reliability of the battery cell.

[0117] The technical solutions described in the embodiments of this application are applicable to batteries and electrical devices that use batteries.

[0118] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0119] It should be understood that the technical solutions described in the embodiments of this application are not limited to the batteries and electrical devices described above, but can also be applied to all batteries including battery boxes and electrical devices using batteries. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as examples.

[0120] Figure 1 is a schematic diagram of the structure of a vehicle provided in some embodiments of this application.

[0121] Referring again to Figure 1, a battery 2 is installed inside the vehicle 1. The battery 2 can be located at the bottom, front, or rear of the vehicle 1. The battery 2 can be used to power the vehicle 1; for example, the battery 2 can serve as the operating power source for the vehicle 1.

[0122] Vehicle 1 may also include controller 3 and motor 4. Controller 3 is used to control battery 2 to supply power to motor 4, for example, for the power needs of vehicle 1 during start-up, navigation and driving.

[0123] In some embodiments of this application, the battery 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0124] Figure 2 is a schematic diagram of the exploded structure of a battery provided in some embodiments of this application.

[0125] Referring again to Figure 2, battery 2 includes a housing 5 and individual battery cells, with the individual battery cells housed within the housing 5.

[0126] The housing 5 is used to house individual battery cells, and the housing 5 can have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, and together define a housing space 5c for housing the individual battery cells. The second housing portion 5b may be a hollow structure with one end open, and the first housing portion 5a may be a plate-like structure, with the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c; alternatively, both the first housing portion 5a and the second housing portion 5b may be hollow structures with one side open, with the open side of the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c. Of course, the first housing portion 5a and the second housing portion 5b can have various shapes, such as cylinders, cuboids, etc.

[0127] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

[0128] Assuming that the first box section 5a covers the top of the second box section 5b, the first box section 5a can also be called the upper box cover, and the second box section 5b can also be called the lower box.

[0129] In battery 2, there can be one or more individual battery cells. If there are multiple individual battery cells, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple individual battery cells are connected in both series and parallel configurations. Multiple individual battery cells can be directly connected in series, parallel, or in a mixed configuration and then housed within housing 5. Alternatively, multiple individual battery cells can first be connected in series, parallel, or in a mixed configuration to form battery module 6, and then multiple battery modules 6 can be connected in series, parallel, or in a mixed configuration to form a whole and housed within housing 5.

[0130] Figure 3 is a schematic diagram of the structure of a battery module provided in some embodiments of this application.

[0131] In some embodiments, continuing to refer to the figures, there are multiple battery cells 7, which are first connected in series, parallel, or mixed to form a battery module 6. The multiple battery modules 6 are then connected in series, parallel, or mixed to form a whole and housed in a casing.

[0132] Multiple battery cells 7 in battery module 6 can be electrically connected through a busbar component to achieve parallel, series, or mixed connection of multiple battery cells 7 in battery module 6.

[0133] Figure 4 is a three-dimensional structural schematic diagram of a battery cell provided in some embodiments of this application; Figure 5 is an exploded structural schematic diagram of the battery cell shown in Figure 4; Figure 6 is a side view structural schematic diagram of the battery cell shown in Figure 4; Figure 7 is a cross-sectional structural schematic diagram along AA in Figure 6; Figure 8 is a partially enlarged structural schematic diagram at F in Figure 7; Figure 9 is a partially enlarged structural schematic diagram at H in Figure 7; Figure 10 is a front view structural schematic diagram of another battery cell provided in some embodiments of this application; Figure 11 is a partially enlarged structural schematic diagram at G in Figure 10; and Figure 12 is a partially enlarged structural schematic diagram at K in Figure 10.

[0134] Referring to Figures 4 to 12, this application embodiment provides a battery cell 7, which includes an electrode assembly 10, a housing 20, a first end cap 30a, and a second end cap 30b. The housing 20 has a first opening 21a and a second opening 21b, which are located at opposite ends of the housing 20 along a first direction X. The housing 20 includes a main body 22, a first thickened portion 23a, and a second thickened portion 23b. The main body 22 surrounds the electrode assembly 10. The first thickened portion 23a is connected to the main body 22 and is arranged circumferentially along the first opening 21a. The second thickened portion 23b is connected to the main body 22 and is arranged circumferentially along the second opening 21b. The thickness of the first thickened portion 23a is greater than the thickness of the main body 22, and the thickness of the second thickened portion 23b is greater than the thickness of the main body 22. The first end cap 30a is connected to the first thickened portion 23a and covers the first opening 21a. The second end cap 30b is connected to the second thickened portion 23b and covers the second opening 21b.

[0135] For example, an end cap refers to a component that covers the opening of the housing 20 to isolate the internal environment of the battery cell 7 from the external environment. Optionally, the shape of the end cap can be adapted to the shape of the housing 20 to fit the housing 20. Optionally, the end cap can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap is not easily deformed when subjected to compression and impact, enabling the battery cell 7 to have higher structural strength and improved reliability. Functional components such as terminal groups can be provided on the end cap. The material of the end cap can also be various. For example, the end cap can be made of, but is not limited to, metallic or non-metallic materials. For example, metallic materials can be copper, aluminum, or stainless steel; non-metallic materials can be polyethylene, polypropylene, or polyvinyl chloride.

[0136] The housing 20 is a component used to cooperate with the end cap to form the internal environment of the battery cell 7. This internal environment can accommodate the electrode assembly 10, electrolyte, and other components. The housing 20 and the end cap can be independent components. An opening can be provided on the housing 20, and the end cap closes the opening to form the internal environment of the battery cell 7. Optionally, the end cap and housing 20 can be integrated. Specifically, the end cap and housing 20 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 20, the end cap closes the housing 20. The housing 20 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 20 can be determined according to the specific shape and size of the electrode assembly 10. The housing 20 can be made of various materials; for example, the housing 20 can be made of, but is not limited to, metallic or non-metallic materials. For example, metallic materials can be copper, aluminum, or stainless steel; non-metallic materials can be polyethylene, polypropylene, or polyvinyl chloride, etc.

[0137] The electrode assembly 10 is the core component for enabling the charging and discharging function of the battery cell 7. The electrode assembly 10 can be a wound structure, a stacked structure, or other structures. There can be one electrode assembly 10 or multiple electrode assemblies.

[0138] In this embodiment of the application, the housing 20 has a first opening 21a and a second opening 21b, the first opening 21a and the second opening 21b are respectively located at both ends of the housing 20 along the first direction X, the first end cap 30a covers the first opening 21a of the housing 20, and the second end cap 30b covers the second opening 21b of the housing 20, so as to isolate the internal environment of the battery cell 7 from the external environment.

[0139] The first end cap 30a and the second end cap 30b can be made of the same material or different materials. As an example, making the first end cap 30a and the second end cap 30b of the same material simplifies the manufacturing process and reduces costs.

[0140] In some examples, the first thickened portion 23a is arranged along the circumference of the first opening 21a and surrounds a portion of the first opening 21a, which is beneficial to balancing the reliability and energy density of the battery cell 7.

[0141] In some examples, the second thickened portion 23b is disposed along the circumference of the second opening 21b and around the portion of the second opening 21b, which is beneficial to balancing the reliability and energy density of the battery cell 7.

[0142] In some examples, the first thickened portion 23a is provided along the circumference of the first opening 21a and surrounds the entire first opening 21a, which can greatly improve the structural strength of the first end cap 30a after it is fitted with the housing 20.

[0143] In some examples, the second thickened portion 23b is provided along the circumference of the second opening 21b and surrounds the entire second opening 21b, which can greatly improve the structural strength of the second end cap 30b after it is fitted with the housing 20.

[0144] In some examples, the main body 22, the first thickened portion 23a, and the second thickened portion 23b are integrally formed by stamping on the housing 20.

[0145] In some examples, the main body 22, the first thickened portion 23a, and the second thickened portion 23b are each formed independently, and the first thickened portion 23a and the second thickened portion 23b are fixedly connected to the main body 22 by a connection process. Optionally, the connection method between the first end cap 30a and the first thickened portion 23a can be, but is not limited to, welding, bolting, bonding, snap-fitting, or riveting, and can be selected according to the actual application environment. Optionally, the connection method between the second end cap 30b and the second thickened portion 23b can be, but is not limited to, welding, bolting, bonding, snap-fitting, or riveting, and can be selected according to the actual application environment.

[0146] The first end cap 30a is sealed to the first thickened portion 23a, and the second end cap 30b is sealed to the second thickened portion 23b to form a sealed space for accommodating the electrode assembly 10 and the electrolyte. Exemplarily, the first end cap 30a is welded to the first thickened portion 23a, and the second end cap 30b is welded to the second thickened portion 23b. Welding simultaneously achieves sealing and fixation between the first end cap 30a and the first thickened portion 23a, as well as sealing and fixation between the second end cap 30b and the second thickened portion 23b, which helps reduce the structural complexity of the battery cell 7.

[0147] The thickness of the first thickened portion 23a is greater than the thickness of the main body portion 22, so that the first thickened portion 23a has higher strength. The first thickened portion 23a can protrude from the inner surface of the main body portion 22, or from the outer surface of the main body portion 22, or from both the inner and outer surfaces of the main body portion 22.

[0148] The thickness of the second thickened portion 23b is greater than the thickness of the main body portion 22, so that the second thickened portion 23b has higher strength. The second thickened portion 23b can protrude from the inner surface of the main body portion 22, or from the outer surface of the main body portion 22, or from both the inner and outer surfaces of the main body portion 22.

[0149] The above technical solution provides a relatively thick first thickened portion 23a along the circumference of the first opening 21a on the housing 20, and connects the first end cap 30a to the first thickened portion 23a. The thicker first thickened portion 23a has higher structural strength, thereby improving the structural strength of the first end cap 30a after it is fitted with the housing 20, and reducing the risk of cracking and failure at the connection point between the first end cap 30a and the housing 20. Similarly, by providing a relatively thick second thickened portion 23b along the circumference of the second opening 21b on the housing 20, and connecting the second end cap 30b to the second thickened portion 23b, the thicker second thickened portion 23b has higher structural strength, thereby improving the structural strength of the second end cap 30b after it is fitted with the housing 20, and reducing the risk of cracking and failure at the connection point between the second end cap 30b and the housing 20. This effectively improves the reliability of the battery cell 7.

[0150] This embodiment only increases the thickness of the first thickened portion 23a and the second thickened portion 23b. Compared with the solution of increasing the overall thickness of the casing 20, this embodiment can reduce the weight of the casing 20 and increase the energy density of the battery cell 7.

[0151] In some embodiments, the housing 20 further includes a first transition portion connected between the main body portion 22 and the first thickened portion 23a. The thickness of the first transition portion gradually increases in the first direction X, from the housing 20 to the first end cap 30a. This reduces the abrupt thickness change between the main body portion 22 and the first thickened portion 23a, thereby reducing the risk of stress concentration and improving the reliability of the housing 20.

[0152] In some embodiments, the housing 20 further includes a second transition portion connected between the main body portion 22 and the second thickened portion 23b. The thickness of the second transition portion gradually increases in the first direction X, from the housing 20 to the second end cap 30b. This reduces the abrupt thickness change between the main body portion 22 and the second thickened portion 23b, thereby reducing the risk of stress concentration and improving the reliability of the housing 20.

[0153] In some embodiments, the first thickened portion 23a protrudes relative to the inner surface of the main body portion 22.

[0154] The inner surface of the main body 22 is the side of the main body 22 facing the electrode assembly 10, and the first thickened portion 23a protrudes towards the interior of the housing 20. When the thickness of the first thickened portion 23a is constant, the first thickened portion 23a protrudes from the inner surface of the main body 22, which can reduce the occupancy rate of the first thickened portion 23a on the outer space of the housing 20, thereby reducing the maximum size of the housing 20, making full use of the internal space of the housing 20, and helping to improve the energy density of the battery cell 7.

[0155] In some embodiments, the first thickened portion 23a protrudes relative to the inner surface of the main body portion 22, and the outer surface of the main body portion 22 is flush with the outer surface of the first thickened portion 23a. This improves the flatness of the outer surface of the housing 20 and enhances its appearance.

[0156] In some embodiments, the first thickened portion 23a protrudes relative to the outer surface of the main body portion 22.

[0157] The outer surface of the main body 22 is the surface of the main body 22 that faces away from the electrode assembly 10, and the first thickened portion 23a protrudes outward toward the housing 20. When the thickness of the first thickened portion 23a is constant, the first thickened portion 23a protrudes from the outer surface of the main body 22, which can reduce the occupancy rate of the first thickened portion 23a on the internal space of the housing 20, thereby reducing the risk of interference between the first thickened portion 23a and the electrode assembly 10, and helping to further improve the reliability of the battery cell 7.

[0158] In some embodiments, the second thickened portion 23b protrudes relative to the inner surface of the main body portion 22.

[0159] The inner surface of the main body 22 is the side of the main body 22 facing the electrode assembly 10, and the second thickened portion 23b protrudes towards the interior of the housing 20. When the thickness of the second thickened portion 23b is constant, the second thickened portion 23b protrudes from the inner surface of the main body 22, which can reduce the occupancy rate of the second thickened portion 23b on the outer space of the housing 20, thereby reducing the maximum size of the housing 20, making full use of the internal space of the housing 20, and helping to improve the energy density of the battery cell 7.

[0160] In some embodiments, the second thickened portion 23b protrudes relative to the inner surface of the main body portion 22, and the outer surface of the main body portion 22 is flush with the outer surface of the second thickened portion 23b. This improves the flatness of the outer surface of the housing 20 and enhances its appearance.

[0161] In some embodiments, the second thickened portion 23b protrudes relative to the outer surface of the main body portion 22.

[0162] The outer surface of the main body 22 is the surface of the main body 22 that faces away from the electrode assembly 10, and the second thickened portion 23b protrudes outward toward the housing 20. When the thickness of the second thickened portion 23b is constant, the second thickened portion 23b protruding from the outer surface of the main body 22 can reduce the occupancy rate of the second thickened portion 23b on the internal space of the housing 20, thereby reducing the risk of interference between the second thickened portion 23b and the electrode assembly 10, which is beneficial to further improving the reliability of the battery cell 7.

[0163] In some embodiments, the first thickened portion 23a is disposed around the first opening 21a.

[0164] The first thickened portion 23a surrounds the first opening 21a, which can further improve the structural strength of the first end cap 30a after it is fitted with the housing 20, thereby further improving the energy density of the battery cell 7.

[0165] In some embodiments, the second thickened portion 23b is disposed around the second opening 21b.

[0166] The second thickened portion 23b surrounds the second opening 21b, which can further improve the structural strength of the second end cap 30b after it is fitted with the housing 20, thereby further improving the energy density of the battery cell 7.

[0167] In some embodiments, in the first direction X, the first thickened portion 23a extends beyond the first end cap 30a near the end of the electrode assembly 10.

[0168] The first thickened portion 23a is used to connect with the first end cap 30a and form a first connecting portion. In the first direction X, the end of the first thickened portion 23a near the electrode assembly 10 extends beyond the first end cap 30a, so that the first connecting portion is located within the range of the first thickened portion 23a, thereby further ensuring and improving the strength of the first end cap 30a after it is fitted with the housing 20, thereby further improving the reliability of the battery cell 7.

[0169] In some embodiments, in the first direction X, the second thickened portion 23b extends beyond the second end cap 30b at one end near the electrode assembly 10.

[0170] The second thickened portion 23b is used to connect with the second end cap 30b and form a second connecting portion. In the first direction X, the end of the second thickened portion 23b near the electrode assembly 10 extends beyond the second end cap 30b, so that the second connecting portion is located within the range of the second thickened portion 23b, thereby further ensuring and improving the strength of the second end cap 30b after it is fitted with the housing 20, thereby further improving the reliability of the battery cell 7.

[0171] In some embodiments, the electrode assembly 10 includes a first electrode plate, the first electrode plate including a first coating area and a first tab extending from an end of the first coating area along a first direction X. A first thickened portion 23a protrudes relative to the inner surface of the main body portion 22, and the first coating area does not overlap with the first thickened portion 23a in a direction perpendicular to the first direction X.

[0172] For example, the electrode assembly 10 further includes a second electrode, the first electrode and the second electrode having opposite polarities, and the electrode assembly 10 operates primarily by the movement of metal ions between the first electrode and the second electrode. One of the first electrode and the second electrode is a positive electrode, and the other of the first electrode and the second electrode is a negative electrode.

[0173] There can be one or more first electrodes, and one or more second electrodes. The number of first electrodes and second electrodes can be determined according to the structure of the electrode assembly 10.

[0174] In some examples, the first electrode is the negative electrode and the second electrode is the positive electrode.

[0175] The first coating area is the electrogenerating part of the first electrode, and the active material inside it is used to undergo an electrochemical reaction with the electrolyte to generate a charging and discharging process. The first tab extends from the end of the first coating area along the first direction X and is used to conduct the electrical energy generated by the first coating area. The first coating area includes a current collector and an active material layer.

[0176] When the first thickened portion 23a protrudes from the inner surface of the main body portion 22, the first coating area and the first thickened portion 23a do not overlap in the direction perpendicular to the first direction X. This reduces the risk of interference between the first thickened portion 23a and the first coating area affecting the electrical performance of the electrode assembly 10. As a result, the maximum size of the housing 20 can be reduced, and the internal space of the housing 20 can be fully utilized to improve the energy density of the battery cell 7, while reducing the adverse effects of the first thickened portion 23a on the electrode assembly 10.

[0177] In some embodiments, the second thickened portion 23b protrudes relative to the inner surface of the main body portion 22, and the first coating area does not overlap with the second thickened portion 23b in a direction perpendicular to the first direction X.

[0178] When the second thickened portion 23b protrudes from the inner surface of the main body portion 22, the first coating area and the second thickened portion 23b do not overlap in the direction perpendicular to the first direction X. This reduces the risk of interference between the second thickened portion 23b and the first coating area affecting the electrical performance of the electrode assembly 10. As a result, the maximum size of the housing 20 can be reduced, and the internal space of the housing 20 can be fully utilized to improve the energy density of the battery cell 7, while reducing the adverse effects of the second thickened portion 23b on the electrode assembly 10.

[0179] In some embodiments, the electrode assembly 10 further includes a spacer that covers the first coating area and does not overlap with the first thickened portion 23a in a direction perpendicular to the first direction X.

[0180] For example, the second electrode includes a second coated area and a second tab extending from an end of the second coated area along a first direction X. A spacer is used to insulate the first coated area of ​​the first electrode and the second coated area of ​​the second electrode. The material of the spacer may be, but is not limited to, polypropylene or polyethylene, etc.

[0181] When the first thickened portion 23a protrudes from the inner surface of the main body portion 22, the separator and the first thickened portion 23a do not overlap in the direction perpendicular to the first direction X. This reduces the risk of insulation failure between the first electrode and the second electrode due to interference between the first thickened portion 23a and the separator. As a result, the maximum size of the housing 20 can be reduced, the internal space of the housing 20 can be fully utilized to improve the energy density of the battery cell 7, and the adverse effects of the first thickened portion 23a on the electrode assembly 10 can be further reduced.

[0182] In some embodiments, the spacer does not overlap with the second thickened portion 23b in a direction perpendicular to the first direction X.

[0183] When the second thickened portion 23b protrudes from the inner surface of the main body portion 22, the separator and the second thickened portion 23b do not overlap in the direction perpendicular to the first direction X. This reduces the risk of insulation failure between the first electrode and the second electrode due to interference between the second thickened portion 23b and the separator. As a result, the maximum size of the housing 20 can be reduced, the internal space of the housing 20 can be fully utilized to improve the energy density of the battery cell 7, and the adverse effects of the second thickened portion 23b on the electrode assembly 10 can be further reduced.

[0184] In some embodiments, the electrode assembly 10 has a flat region comprising a plurality of electrodes stacked along a second direction Y, wherein the first direction X intersects the second direction Y.

[0185] For example, the second direction Y can be understood as the thickness direction of the electrode assembly 10. During the cycle of use, the electrode assembly 10 will expand to a certain extent along the second direction Y.

[0186] In some examples, the electrode assembly 10 has a wound structure, with the first electrode and the second electrode wound together. The wound electrode assembly 10 includes a flat region and a bent region, with the bent region connected to one end of the flat region along a third direction. The first direction X, the second direction Y, and the third direction are perpendicular to each other. The first electrode and the second electrode located in the flat region are alternately stacked along the second direction Y.

[0187] In some examples, the electrode assembly 10 has a stacked structure, with the first electrode and the second electrode alternately stacked along the second direction Y. The electrode assembly 10 with the stacked structure has a flat structure as a whole, that is, the electrode assembly 10 with the stacked structure can be used as a flat region as a whole.

[0188] The above technical solution can reduce the impact of the expansion of the electrode assembly 10 on the first end cover 30a and the second end cover 30b, thereby further reducing the risk of cracking and failure at the connection between the first end cover 30a and the housing 20, and further reducing the risk of cracking and failure at the connection between the second end cover 30b and the housing 20.

[0189] In some embodiments, the battery cell 7 further includes a support 40, which is connected between the first end cap 30a and the electrode assembly 10. The first thickened portion 23a has a larger dimension in the first direction X than the second thickened portion 23b in the first direction X.

[0190] The bracket 40 can be entirely located between the first end cap 30a and the electrode assembly 10, or only partially located between the first end cap 30a and the electrode assembly 10. The bracket 40 can be independent of the first end cap 30a, with the first end cap 30a and the electrode assembly 10 clamping and fixing the bracket 40. Alternatively, the bracket 40 can be fixedly connected to the first end cap 30a; for example, the bracket 40 can be fixedly connected to the first end cap 30a by means of welding, bonding, snap-fitting, bolting, or riveting, but is not limited to these methods.

[0191] When the battery cell 7 is subjected to external impact, the bracket 40 can limit the vibration of the electrode assembly 10, thereby reducing the tension on the tabs of the electrode assembly 10, reducing the risk of tab tearing, and improving the reliability of the battery cell 77.

[0192] Optionally, the bracket 40 may be made of insulating materials such as polyethylene, polypropylene, polyvinyl chloride or rubber to reduce the risk of the first end cap 30a conducting the positive and negative electrodes of the electrode assembly 10 and improve reliability.

[0193] A bracket 40 is provided between the first end cap 30a and the electrode assembly 10, which also allows the first end cap 30a and the electrode assembly 10 to have a larger space in the first direction X, thereby increasing the size range of the first thickened part 23a in the first direction X. Thus, by increasing the size of the first thickened part 23a in the first direction X, the above technical solution can further improve the strength of the first end cap 30a after it is fitted with the housing 20.

[0194] Optionally, the bracket 40 and the first end cap 30a are integrally formed structures.

[0195] On the one hand, the absence of an additional connection process to connect the bracket 40 and the first end cap 30a simplifies the manufacturing process. On the other hand, compared to connecting the bracket 40 and the first end cap 30a through an additional connection process, the integrated structure of the bracket 40 and the first end cap 30a provides a higher degree of connection strength.

[0196] In some embodiments, the battery cell 7 further includes a first insulating member and a second insulating member, the first insulating member being connected to the side of the first end cap 30a near the electrode assembly 10, and the second insulating member being connected to the side of the second end cap 30b near the electrode assembly 10.

[0197] In some embodiments, the first end cap 30a includes a first cap body 31 and a first extension 32. The first extension 32 is connected to the first cap body 31 and protrudes from the side surface of the first cap body 31 near the housing 20. At least a portion of the first extension 32 is located inside the housing 20 and connected to the first thickened portion 23a. The first cap body 31 is located outside the housing 20 and connected to the first thickened portion 23a.

[0198] Both the first cover body 31 and the first extension 32 are connected to the first thickened portion 23a. The first extension 32 extends along the first direction X. The introduction of the first extension 32 increases the overall contact area between the first end cover 30a and the first thickened portion 23a, thereby further improving the connection strength between the first end cover 30a and the housing 20. As an example, both the first cover body 31 and the first extension 32 are welded to the first thickened portion 23a.

[0199] Optionally, the first cover body 31 and the first extension 32 are integrally formed. On the one hand, there is no need to connect the first cover body 31 and the first extension 32 through an additional connecting process, simplifying the manufacturing process. On the other hand, compared with connecting the first cover body 31 and the first extension 32 through an additional connecting process, the integral structure of the first cover body 31 and the first extension 32 has a higher connection strength.

[0200] The first cover body 31 and the first extension 32 can be made of the same material or different materials. As an example, making the first cover body 31 and the first extension 32 of the same material simplifies the manufacturing process and reduces costs.

[0201] In some embodiments, the second end cap 30b includes a second cap body 33 and a second extension 34. The second extension 34 is connected to the second cap body 33 and protrudes from the side surface of the second cap body 33 near the housing 20. At least a portion of the second extension 34 is located inside the housing 20 and connected to the second thickened portion 23b. The second cap body 33 is located outside the housing 20 and connected to the second thickened portion 23b.

[0202] The second cover body 33 and the second extension 34 are both connected to the second thickened portion 23b. The second extension 34 extends along the first direction X. The introduction of the second extension 34 increases the overall contact area between the second end cover 30b and the second thickened portion 23b, thereby further improving the connection strength between the second end cover 30b and the housing 20. As an example, the second cover body 33 and the second extension 34 are both welded to the second thickened portion 23b.

[0203] Optionally, the second cover body 33 and the second extension 34 are integrally formed. On the one hand, there is no need to connect the second cover body 33 and the second extension 34 through an additional connecting process, simplifying the manufacturing process. On the other hand, compared with connecting the second cover body 33 and the second extension 34 through an additional connecting process, the integral structure of the second cover body 33 and the second extension 34 has a higher connection strength.

[0204] The second cover body 33 and the second extension 34 can be made of the same material or different materials. As an example, making the second cover body 33 and the second extension 34 of the same material simplifies the manufacturing process and reduces costs.

[0205] In some embodiments, the battery cell 7 further includes a pressure relief mechanism 50, and the housing 20 includes two opposing first side plates 24, with the pressure relief mechanism 50 disposed on one of the two first side plates 24.

[0206] The pressure relief mechanism 50 refers to an element or component that is activated to release internal pressure or temperature when the internal pressure or temperature of the battery cell 7 reaches a predetermined threshold. This threshold design varies depending on design requirements and may depend on one or more materials among the positive electrode, negative electrode, electrolyte, and separator in the battery cell 7. The pressure relief mechanism 50 can take the form of an explosion-proof valve, gas valve, pressure relief valve, or safety valve, and can specifically employ pressure-sensitive or temperature-sensitive elements or structures. That is, when the internal pressure or temperature of the battery cell 7 reaches the predetermined threshold, the pressure relief mechanism 50 actuates, or a weak structure within the pressure relief mechanism 50 is damaged, thereby creating an opening or channel for the release of internal pressure or temperature.

[0207] Compared to the first end cap 30a and the second end cap 30b, the area of ​​the first side plate 24 is larger. Therefore, setting the pressure relief mechanism 50 on the first side plate 24 can reduce the difficulty of setting the pressure relief mechanism 50.

[0208] In some embodiments, the first end cap 30a is provided with components such as an injection hole and an electrode terminal, and the pressure relief mechanism 50 is provided on the first side plate 24, which can free up space for components such as the injection hole and the electrode terminal, thereby facilitating the optimization of the layout of other components on the first end cap 30a.

[0209] In some embodiments, the second end cap 30b is provided with components such as an injection hole and electrode terminals, and the pressure relief mechanism 50 is provided on the first side plate 24, which can free up space for components such as the injection hole and electrode terminals, thereby facilitating the optimization of the layout of other components on the second end cap 30b.

[0210] In some embodiments, the other of the two first side plates 24 is provided with a weld. Since the pressure relief mechanism 50 is provided on one of the two first side plates 24, by providing the weld on the first side plate 24 of the two first side plates 24 that is not provided with the pressure relief mechanism 50, the impact of the weld on the pressure relief mechanism 50 can be reduced, thereby improving the reliability of the pressure relief mechanism 50.

[0211] In some embodiments, the main body 22 and the first thickened part 23a are integrally formed structures.

[0212] On the one hand, the manufacturing process is simplified because there is no need to connect the main body 22 and the first thickened part 23a through an additional connection process. On the other hand, compared with connecting the main body 22 and the first thickened part 23a through an additional connection process, the main body 22 and the first thickened part 23a, which are of an integral structure, have a higher connection strength.

[0213] In some embodiments, the main body 22 and the second thickened part 23b are integrally formed structures.

[0214] On the one hand, the manufacturing process is simplified because there is no need to connect the main body 22 and the second thickened part 23b through an additional connection process. On the other hand, compared with connecting the main body 22 and the second thickened part 23b through an additional connection process, the one-piece structure of the main body 22 and the second thickened part 23b has a higher connection strength.

[0215] In some embodiments, the first end cap 30a is welded to the housing 20. The welding is highly reliable, convenient, quick, and low in cost.

[0216] In some embodiments, the second end cap 30b is welded to the housing 20. The welding is highly reliable, convenient, quick, and low in cost.

[0217] According to some embodiments of this application, this application also provides a battery, including a battery cell 7 of any of the above solutions.

[0218] In some embodiments, a plurality of battery cells 7 are sequentially attached along the second direction Y, the first thickened portion 23a protrudes from the inner surface of the main body portion 22, the second thickened portion 23b protrudes from the inner surface of the main body portion 22, and the first direction X and the second direction Y intersect.

[0219] The phrase "multiple battery cells 7 are sequentially bonded together along the second direction Y" means that the outer surfaces of the casings 20 of two adjacent battery cells 7 along the second direction Y are partially bonded together. Thus, when multiple battery cells 7 are sequentially bonded together along the second direction Y, the first thickened portion 23a protrudes relative to the inner surface of the main body 22, and the second thickened portion 23b protrudes relative to the inner surface of the main body 22. This prevents gaps from forming between adjacent battery cells 7, improving the battery's structural compactness and thus contributing to increased overall battery energy density.

[0220] As an example, the multiple battery cells 7 can be, but are not limited to, two battery cells 7, three battery cells 7, four battery cells 7, or more battery cells 7.

[0221] Figure 13 is a partial structural schematic diagram of a battery provided in some embodiments of this application, Figure 14 is a partial enlarged structural schematic diagram at point M in Figure 13, and Figure 15 is a partial enlarged structural schematic diagram at point N in Figure 13.

[0222] Referring again to Figures 13 to 15, in some embodiments, multiple battery cells 7 are spaced apart along the second direction Y. A first thickened portion 23a protrudes relative to the outer surface of the main body portion 22, and a second thickened portion 23b protrudes relative to the outer surface of the main body portion 22. The first direction X and the second direction Y intersect. The battery cell 7 also includes a separating member 60, which is disposed between the main bodies 22 of two adjacent battery cells 7. In the second direction Y, the separating member 60 does not overlap with the first thickened portion 23a, and the separating member 60 does not overlap with the second thickened portion 23b.

[0223] For example, the separator 60 is a component that assists in the electrical connection, buffering, reinforcement, and temperature regulation of the battery cell 7 in the battery. For example, the separator 60 may be, but is not limited to, a buffer pad, a thermal management component, or a reinforcement component.

[0224] The first thickened portion 23a protrudes from the outer surface of the main body portion 22, and the second thickened portion 23b protrudes from the outer surface of the main body portion 22. The first thickened portion 23a and the second thickened portion 23b of two adjacent battery cells 7 along the second direction Y can together form an accommodating space.

[0225] In some examples, a portion of the separator 60 is housed in the accommodating space, that is, a portion of the separator 60 is disposed between the main body portions 22 of two adjacent battery cells 7, and another portion is located between the first thickened portions 23a of two adjacent battery cells 7, and / or between the second thickened portions 23b of two adjacent battery cells 7.

[0226] In other examples, the separator 60 is completely housed in the accommodating space, that is, the separator 60 is disposed between the main body portions 22 of two adjacent battery cells 7, and in the second direction Y, the separator 60 does not overlap with the first thickened portion 23a and the second thickened portion 23b.

[0227] Optionally, the separator 60 includes a buffer pad, at least a portion of which is made of an elastic material, such as rubber or other materials. The buffer pad is a rubber structure with compressibility, which can reduce collisions and damage between battery cells 7. It should be noted that the buffer pad provided in the embodiments of this application can also be replaced with a heat insulation pad, a heat-conducting pad, or other pad-shaped or plate-shaped structures with cooling or heating functions, which can be selected according to the actual application environment.

[0228] Optionally, the separating component 60 includes a thermal management component. The thermal management component is inserted between the main body portions 22 of two adjacent battery cells 7. The thermal management component is a hollow structure with internal thermal management channels through which fluids such as coolant can pass to exchange heat with the battery cells 7, thereby maintaining the temperature of the battery cells 7 within a normal range, reducing the probability of thermal runaway, and improving battery reliability. Specifically, the thermal management component is a cooling plate; in other embodiments, it can also be a heat-conducting plate or other structures that can adjust the temperature of the battery cells 7. Through the above technical solution, a thermal management component can be accommodated between the main body portions 22 of two adjacent battery cells 7, which improves the space utilization of the battery and helps reduce and mitigate thermal runaway of the battery cells 7, thus improving the reliability of the battery cells 7.

[0229] Optionally, the separator 60 includes a reinforcing member, which is a structure that strengthens the overall battery structure and improves the reliability and stability of the battery cell 7. The reinforcing member can be a reinforcing plate. In some embodiments, the reinforcing plate can be connected to one or more battery cells 7, for example, by adhesive bonding, to structurally reinforce the battery cell 7 or the battery module formed by the battery cells 7. In other embodiments, the reinforcing member may not be directly connected to the battery cell 7.

[0230] The above technical solution, by placing the separator 60 between the main body portions 22 of two adjacent battery cells 7, can, on the one hand, fully utilize the accommodating space formed by the first thickened portion 23a and the second thickened portion 23b of the two adjacent battery cells 7, thereby improving the space utilization rate of the battery, making the battery structure more compact and reliable, and contributing to higher energy density. On the other hand, the first thickened portion 23a and the second thickened portion 23b can restrict the displacement of the separator 60, improving battery reliability. Furthermore, in the second direction Y, the separator 60 does not overlap with the first thickened portion 23a, nor with the second thickened portion 23b, reducing the risk of interference from the first thickened portion 23a and the second thickened portion 23b, which could lead to damage to the separator 60.

[0231] According to some embodiments of this application, this application also provides an electrical device including a battery of any of the above-described embodiments, the battery being used to provide electrical energy.

[0232] To better understand the battery cell 7 provided in the embodiments of this application, based on the same inventive concept, embodiments of the battery cell 7 in practical applications are provided here for illustration.

[0233] This application provides a battery cell 7, which includes an electrode assembly 10, a housing 20, a first end cap 30a, and a second end cap 30b. The housing 20 has a first opening 21a and a second opening 21b, which are located at opposite ends of the housing 20 along a first direction X. The housing 20 includes a main body 22, a first thickened portion 23a, and a second thickened portion 23b. The main body 22 surrounds the electrode assembly 10. The first thickened portion 23a is connected to the main body 22 and is arranged circumferentially along the first opening 21a. The second thickened portion 23b is connected to the main body 22 and is arranged circumferentially along the second opening 21b. The thickness of the first thickened portion 23a is greater than the thickness of the main body 22, and the thickness of the second thickened portion 23b is greater than the thickness of the main body 22. The first end cap 30a is connected to the first thickened portion 23a and covers the first opening 21a. The second end cap 30b is connected to the second thickened portion 23b and covers the second opening 21b.

[0234] The above technical solution provides a relatively thick first thickened portion 23a along the circumference of the first opening 21a on the housing 20, and connects the first end cap 30a to the first thickened portion 23a. The thicker first thickened portion 23a has higher structural strength, thereby improving the structural strength of the first end cap 30a after it is fitted with the housing 20, and reducing the risk of cracking and failure at the connection point between the first end cap 30a and the housing 20. Similarly, by providing a relatively thick second thickened portion 23b along the circumference of the second opening 21b on the housing 20, and connecting the second end cap 30b to the second thickened portion 23b, the thicker second thickened portion 23b has higher structural strength, thereby improving the structural strength of the second end cap 30b after it is fitted with the housing 20, and reducing the risk of cracking and failure at the connection point between the second end cap 30b and the housing 20. This effectively improves the reliability of the battery cell 7.

[0235] This embodiment only increases the thickness of the first thickened portion 23a and the second thickened portion 23b. Compared with the solution of increasing the overall thickness of the casing 20, this embodiment can reduce the weight of the casing 20 and increase the energy density of the battery cell 7.

[0236] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0237] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

A single battery cell, comprising: Electrode assembly; A housing having a first opening and a second opening, the first opening and the second opening being located at opposite ends of the housing along a first direction, the housing including a main body, a first thickened portion and a second thickened portion, the main body being disposed around the electrode assembly, the first thickened portion being connected to the main body and disposed circumferentially along the first opening, the second thickened portion being connected to the main body and disposed circumferentially along the second opening, the thickness of the first thickened portion being greater than the thickness of the main body, and the thickness of the second thickened portion being greater than the thickness of the main body; The first end cap is connected to the first thickened portion and covers the first opening; The second end cap is connected to the second thickened portion and covers the second opening. According to claim 1, the battery cell, wherein, The first thickened portion protrudes relative to the inner surface of the main body portion; and / or, The first thickened portion protrudes relative to the outer surface of the main body portion. The battery cell according to any one of claims 1-2, wherein, The second thickened portion protrudes relative to the inner surface of the main body portion; and / or, The second thickened portion protrudes relative to the outer surface of the main body portion. The battery cell according to any one of claims 1-3, wherein, The first thickened portion is disposed around the first opening; and / or, The second thickened portion is disposed around the second opening. The battery cell according to any one of claims 1-4, wherein, In the first direction, the end of the first thickened portion near the electrode assembly extends beyond the first end cap; and / or, In the first direction, the second thickened portion extends beyond the second end cap at one end near the electrode assembly. The battery cell according to any one of claims 1-5, wherein, The electrode assembly includes a first electrode plate, the first electrode plate including a first coating area and a first tab extending from an end of the first coating area along the first direction; The first thickened portion protrudes relative to the inner surface of the main body portion, and the first coated area does not overlap with the first thickened portion in a direction perpendicular to the first direction. According to claim 6, the battery cell, wherein, The electrode assembly further includes an isolator that covers the first coating area and does not overlap with the first thickened portion in a direction perpendicular to the first direction. The battery cell according to any one of claims 1-7, wherein, The electrode assembly has a flat region comprising a plurality of electrode sheets stacked along a second direction, wherein the first direction intersects the second direction. The battery cell according to any one of claims 1-8, wherein, The battery cell also includes a bracket, which is connected between the first end cap and the electrode assembly; The dimension of the first thickened portion in the first direction is greater than the dimension of the second thickened portion in the first direction. The battery cell according to any one of claims 1-9, wherein, The first end cap includes a first cap body and a first extension. The first extension is connected to the first cap body and protrudes from the surface of the first cap body near the housing. At least a portion of the first extension is located inside the housing and connected to the first thickened portion. The first cap body is located outside the housing and connected to the first thickened portion; and / or, The second end cap includes a second cap body and a second extension. The second extension is connected to the second cap body and protrudes from the side surface of the second cap body near the housing. At least a portion of the second extension is located inside the housing and connected to the second thickened portion. The second cap body is located outside the housing and connected to the second thickened portion. The battery cell according to any one of claims 1-10, wherein, The battery cell also includes a pressure relief mechanism, and the housing includes two opposing first side plates, with the pressure relief mechanism disposed on one of the two first side plates. According to claim 11, the battery cell, wherein, The other of the two first side plates is provided with a weld. The battery cell according to any one of claims 1-12, wherein, The main body and the first thickened part are integrally formed; and / or, The main body and the second thickened part are integrally formed. The battery cell according to any one of claims 1-13, wherein, The first end cap is welded to the housing; and / or, The second end cap is welded to the housing. A battery comprising a plurality of battery cells as described in any one of claims 1-14. The battery according to claim 15, wherein, Multiple battery cells are sequentially attached along a second direction. The first thickened portion protrudes from the inner surface of the main body, and the second thickened portion protrudes from the inner surface of the main body. The first direction and the second direction intersect. The battery according to claim 15, wherein, The plurality of battery cells are spaced apart along a second direction, the first thickened portion protrudes relative to the outer surface of the main body, the second thickened portion protrudes relative to the outer surface of the main body, and the first direction and the second direction intersect. The battery cell further includes a separator, which is disposed between the main body portions of two adjacent battery cells. In the second direction, the separator does not overlap with the first thickened portion and the second thickened portion. An electrical device comprising a battery as described in any one of claims 15-17, the battery being used to provide electrical energy.

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