Battery cell, battery device, and electric device

Abstract

The application discloses a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an end cover and at least one electrode assembly, the shell has an opening, the end cover is arranged on the opening, and the electrode assembly is arranged in the interior of the shell. The shell comprises two first walls arranged oppositely in a first direction, the first direction is the thickness direction of the electrode assembly, at least one first wall comprises a first body part and a first thickened part, the first thickened part is connected to the first body part, the first thickened part is welded to the end cover, the size of the first thickened part is greater than the size of the first body part in the first direction, the first thickened part comprises a first thickened subpart and a second thickened subpart arranged in a second direction, the first thickened subpart passes through the middle section of the first wall, the size of the first thickened subpart is greater than the size of the second thickened subpart in a third direction, the third direction is the thickness direction of the end cover, and the first direction, the second direction and the third direction are perpendicular to each other.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, a battery device, and an electrical device. Background Technology

[0002] In recent years, with the rapid development of new energy technologies, new energy vehicles have been increasingly widely used and are gradually replacing traditional fuel vehicles, becoming one of the mainstream modes of transportation. As the power source of new energy vehicles, the power battery is one of their core components; therefore, the safety performance of the power battery has become a key focus of attention.

[0003] In the development of battery technology, improving the reliability of individual battery cells is a key research direction. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical device, which can improve the reliability of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a housing, an end cap, and an electrode assembly. The housing has an opening; the end cap covers the opening; and the electrode assembly is disposed inside the housing. The housing includes two first walls disposed opposite each other in a first direction, the first direction being the thickness direction of the electrode assembly. At least one first wall includes a first body portion and a first thickened portion. The first thickened portion is connected to the first body portion and welded to the end cap. Along the first direction, the size of the first thickened portion is larger than the size of the first body portion. The first thickened portion includes a first thickened sub-portion and a second thickened sub-portion arranged along a second direction. The first thickened sub-portion passes through a mid-section of the first wall, the mid-section being perpendicular to the second direction. The mid-section is equidistant from both ends of the first wall along the second direction. In a third direction, the size of the first thickened sub-portion is larger than the size of the second thickened sub-portion. The third direction is the thickness direction of the end cap, and the first direction, the second direction, and the third direction are mutually perpendicular.

[0006] In the above solution, by setting the dimension of the first thickened portion along the first direction to be greater than the dimension of the first body portion along the first direction, the risk of cracking at the connection between the first wall and the end cap can be reduced, and the connection stability between the first wall and the end cap can be increased. Since the first thickened sub-part passes through the mid-section, the expansion amount of the electrode assembly portion corresponding to the first thickened sub-part along the first direction is greater than the expansion amount of the electrode assembly portion corresponding to the second thickened sub-part. Therefore, in this embodiment, by setting the dimension of the first thickened sub-part along the third direction to be greater than the dimension of the second thickened sub-part along the third direction, the risk of cracking at the connection position between the housing and the end cap, which is most prone to cracking, is reduced, and the connection stability between the housing and the end cap is further increased.

[0007] In some embodiments, the first thickened portion includes two second thickened sub-portions, which are respectively connected to the two ends of the first thickened sub-portion along the second direction.

[0008] In the above scheme, by providing second thickened sub-parts on both sides of the first thickened sub-part, the range of the first thickened part is increased, further increasing the connection stability between the first wall and the end cap.

[0009] In some embodiments, the first thickened portion is symmetrically arranged in the mid-section along the second direction.

[0010] In the above scheme, the symmetrical structure allows the stress generated when the electrode assembly expands along the first direction to be evenly distributed to the first thickened part, avoiding the risk of cracking caused by local stress concentration. Since the first thickened sub-part passes through the mid-section and has a large expansion amount, the symmetrical design can balance the forces on both sides and improve the overall deformation resistance.

[0011] In some embodiments, the second thickened sub-section extends to the edge of the first wall along the second direction.

[0012] In the above solution, by covering the edge of the first wall with the thickened area, the stress generated by the expansion of the electrode assembly along the second direction can be transferred from the center to the edge, reducing the risk of local cracking caused by stress concentration at the edge.

[0013] In some embodiments, at least a portion of the first thickened sub-part protrudes beyond the second thickened sub-part in the direction from the electrode assembly to the end cap.

[0014] In the above scheme, by setting the first thickened sub-part to protrude from the second thickened sub-part, more of the electrode assembly structure can be accommodated at the position of the first thickened sub-part, thereby improving the energy density of the battery cell.

[0015] In some embodiments, the end of the first thickened sub-part near the first body part is flush with the end of the second thickened sub-part near the first body part.

[0016] In the above scheme, the first thickened sub-part and the second thickened sub-part form a continuous transition in the region near the first body part, which to a certain extent avoids stress concentration points caused by abrupt changes in thickness.

[0017] In some embodiments, the electrode assembly points toward the end cap, and the second thickened sub-part protrudes beyond the first thickened sub-part.

[0018] In the above scheme, by setting the first thickened sub-part to protrude from the second thickened sub-part, more of the electrode assembly structure can be accommodated at the position of the first thickened sub-part, thereby improving the energy density of the battery cell.

[0019] In some embodiments, the first wall has a recess that extends through the first wall in a first direction; the first thickened portion is at least corresponding to the recess; there are two second thickened sub-parts, which are respectively located on both sides of the recess.

[0020] In the above solution, by providing a second thickened sub-part on both sides of the recess, the concentrated stress can be diffused to both sides. When the electrode assembly expands along the first direction, the first thickened part increases the material thickness and disperses the stress to a larger area, thereby avoiding failure of the recess edge due to local stress overload to a certain extent.

[0021] In some embodiments, the end cap includes a cap body and an electrode terminal. The cap body includes a first cap portion and a second cap portion. The first cap portion is recessed relative to the second cap portion in the direction of the housing. The first cap portion is connected to the recess. The electrode terminal is disposed on the first cap portion.

[0022] In the above scheme, by setting the electrode terminals in the recessed first cover portion, the tabs and adapter components can be accommodated in the housing position corresponding to the protruding second cover portion, thereby improving the energy density of the battery cell.

[0023] In some embodiments, the electrode assembly includes an electrode body and a tab, and the battery cell further includes an adapter for connecting the tab to an electrode terminal. The tab and the adapter are welded together to form a solder mark, and the projection of the solder mark along the thickness direction at least partially overlaps with the projection of the first thickened portion along the thickness direction.

[0024] In the above solution, by setting the solder mark formed by the tab and the adapter to correspond with the first thickened part, the internal space of the casing can be saved and the energy density of the battery cell can be increased.

[0025] In some embodiments, along the third direction, the solder mark is closer to the end cap on the side of the first thickened portion away from the opening.

[0026] In the above solution, by placing the solder mark closer to the end cap relative to the first thickened part, the internal space of the casing can be further saved, and the energy density of the battery cell can be further improved.

[0027] In some embodiments, at least a portion of the first thickened sub-part protrudes beyond the second thickened sub-part in the direction from the end cap toward the electrode assembly.

[0028] In the above solution, by making at least a portion of the first thickened sub-part protrude relative to the second thickened sub-part in the direction away from the end cap, the size of the first thickened sub-part along the third direction is made larger than the size of the second thickened sub-part along the third direction, which directly enhances the structural strength of the region with the largest expansion of the electrode assembly.

[0029] In some embodiments, the end of the second thickened sub-part away from the first body part is flush with the end of the first thickened sub-part away from the first body part.

[0030] In the above solution, by setting the upper ends of the first thickened sub-part and the second thickened sub-part to be flush, the end cap can be made easier to manufacture and the manufacturing difficulty can be reduced.

[0031] In some embodiments, the first thickened portion further includes a third thickened sub-portion, which is connected between the first thickened sub-portion and the second thickened sub-portion; the size of the third thickened sub-portion gradually decreases along the direction from the first thickened sub-portion to the second thickened sub-portion.

[0032] In the above scheme, the first thickened sub-part and the second thickened sub-part are connected by the third thickened sub-part. The third thickened sub-part serves as a transition area, and its size gradually decreases along the third direction, making the stiffness change between the first thickened sub-part and the second thickened sub-part smoother and reducing stress concentration points caused by abrupt changes in thickness.

[0033] In some embodiments, the dimension of the third thickened sub-part near the first thickened sub-part along a third direction is equal to the dimension of the first thickened sub-part along a third direction, and the dimension of the third thickened sub-part near the second thickened sub-part along a third direction is equal to the dimension of the second thickened sub-part along a third direction.

[0034] In the above scheme, a continuous transition is formed between the third thickened sub-section and the first and second thickened sub-sections, eliminating stress concentration points caused by abrupt changes in thickness, further reducing the risk of cracking at the connection point between the shell and the end cap, which is most prone to cracking, and further increasing the connection stability between the shell and the end cap.

[0035] In some embodiments, the first wall further includes a first transition portion, which connects the first body portion and the first thickened portion in the third direction; the thickness of the first transition portion gradually decreases in the direction from the first thickened portion to the first body portion.

[0036] In the above solution, by making the stiffness change between the first thickened portion and the first body portion more gradual, stress concentration points caused by abrupt changes in thickness are eliminated. When the electrode assembly expands along the first direction, the stress is gradually dispersed from the first thickened portion to the first body portion through the first transition portion, which to a certain extent avoids the formation of stress peaks at the interface, thereby reducing the risk of cracking.

[0037] In some embodiments, the housing further includes two second walls disposed opposite each other along the second direction, wherein the area of ​​the first wall is larger than the area of ​​the second wall.

[0038] In the above scheme, the first thickened part is set in the first wall with a larger area to enhance its rigidity and strength, which can resist the expansion and deformation trend caused by the large area, making it less likely for deformation and cracking to occur in the more crack-prone areas.

[0039] In some embodiments, at least one of the second walls includes a second body portion and a second thickened portion, the second thickened portion being connected to the second body portion and welded to the end cap, and the size of the second thickened portion being larger than the size of the second body portion along the first direction.

[0040] In the above solution, by thickening the part where the second wall is welded to the end cap, the entire welded position between the shell and the end cap can be reinforced, further increasing the connection stability between the end cap and the shell.

[0041] In some embodiments, the thickness difference between the first thickened portion and the first body portion is L, where L satisfies: 0.05mm≤L≤0.5mm.

[0042] In the above solution, by limiting the thickness difference L between the first thickened part and the first body part to a suitable range, the strengthening effect of the first thickened part can be satisfied without affecting the mold demolding of the shell, thus reducing the processing difficulty.

[0043] In some embodiments, L satisfies: 0.1mm≤L≤0.3mm.

[0044] In the above solution, by further limiting the range of the thickness difference L between the first thickened portion and the first body portion, the strengthening effect of the first thickened portion can be further improved, and the processing difficulty can be further reduced.

[0045] In some embodiments, the minimum width of the first thickened portion along the height direction of the battery cell is H, where H satisfies: 1mm≤H≤10mm.

[0046] In the above scheme, by setting the minimum width H of the first thickened part within a suitable range, the strengthening effect of the first thickened part can be guaranteed to a certain extent without affecting the energy density of the battery cell.

[0047] In some embodiments, H satisfies: 3mm ≤ H ≤ 8mm.

[0048] In the above solution, by further limiting the range of the minimum width H of the first thickened portion, the strengthening effect of the first thickened portion can be further improved, and the impact on the energy density of the battery cell can be further reduced.

[0049] Secondly, embodiments of this application also provide a battery device, including a battery cell of any of the above embodiments.

[0050] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery device, which is used to provide electrical energy.

[0051] The electrical device provided in this application embodiment has the same technical effect as the battery provided in the above embodiment, and will not be described again here. Attached Figure Description

[0052] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0053] Figure 1 This is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0054] Figure 2 Exploded views of battery devices according to some embodiments of this application;

[0055] Figure 3 This is a schematic diagram of the structure of a battery module according to some embodiments of this application;

[0056] Figure 4 This is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0057] Figure 5 These are schematic diagrams of the structure of a battery cell according to some embodiments of this application;

[0058] Figure 6 These are schematic diagrams of the housing structure of some embodiments of this application;

[0059] Figure 7This is a partial cross-sectional schematic diagram of the housing of some embodiments of this application;

[0060] Figure 8 This is a side view of the housing according to some embodiments of this application;

[0061] Figure 9 These are schematic diagrams of the housing structure of some other embodiments of this application;

[0062] Figure 10 These are schematic diagrams of the end cap structure of some embodiments of this application;

[0063] Figure 11 This is an exploded view of an electrode assembly according to some embodiments of this application;

[0064] Figure 12 This is a side view of the housing according to other embodiments of this application;

[0065] Figure 13 This is a side view of the housing according to some embodiments of this application;

[0066] Figure 14 This is a partial cross-sectional schematic diagram of the housing according to other embodiments of this application;

[0067] Figure 15 This is a schematic diagram of the structure of the housing according to some embodiments of this application.

[0068] Explanation of reference numerals in the attached figures:

[0069] 1000, Vehicle; 100, Battery unit; 200, Controller; 300, Motor; 10, Top cover; 30, Housing; 400, Battery module; 20, Battery cell; 22, Housing; 21, End cap; 211, Cover body; 212, Electrode terminal; 213, First cover part; 214, Second cover part; 23, Electrode assembly; 231, Electrode body; 232, Electrode tab; 233, Adapter part; 22a, Opening; 221, First wall; 222, First body part; 223, First thickened part; 224, First thickened sub-part; 225, Second thickened sub-part; 226, Recess; 227, Third thickened sub-part; 228, First transition part; 229, Second wall; 2291, Second body part; 2292, Second thickened part; X, First direction; Y, Second direction; Z, Third direction; W, Mid-section. Detailed Implementation

[0070] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0071] In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.

[0072] In this application, the reference to "embodiment" means that a specific 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 throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0073] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" 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. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances.

[0074] In this application, "multiple" means two or more (including two).

[0075] In this application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc., and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto.

[0076] The battery mentioned in the embodiments of this application may be a single physical module comprising one or more battery cells to provide higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, parallel, or mixed via a busbar.

[0077] In some embodiments, the battery can be a battery module; when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0078] 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.

[0079] 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.

[0080] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0081] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0082] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0083] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0084] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, stainless steel with a silver surface treatment, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium can be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0085] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more.

[0086] In some embodiments, the positive electrode can be made of foamed carbon or foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, or a foamed alloy, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal may also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0087] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0088] As an example, the negative electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, silver-surfaced stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium can be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0089] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0090] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0091] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc.

[0092] In some embodiments, the negative electrode can be made of foamed carbon or foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, or foamed alloy, etc. When foamed metal is used as the negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0093] As an example, lithium source material, potassium metal or sodium metal may also be filled or deposited in the negative electrode current collector, wherein the lithium source material is lithium metal and / or lithium-rich material.

[0094] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0095] In some embodiments, the electrode assembly further includes a separator disposed between the positive and negative electrodes. This application does not impose any particular limitation on the type of separator; any known porous separator with good chemical and mechanical stability can be selected.

[0096] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride, and ceramic.

[0097] 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.

[0098] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0099] In some implementations, the electrode assembly is a stacked structure.

[0100] Multiple positive and negative electrodes can be set separately, and multiple positive and multiple negative electrodes can be stacked alternately.

[0101] 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.

[0102] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0103] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0104] As an example, the separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0105] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0106] 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.

[0107] The battery cell also includes a casing, inside which a cavity is formed to house the electrode assembly. The casing protects the electrode assembly from the outside to prevent external objects from affecting its charging or discharging. During subsequent charging and discharging of the battery cell, the welded joints of the end cap and casing are prone to cracking after the cell cyclically expands, thus reducing the reliability of the battery cell.

[0108] To address the aforementioned technical problems, this application provides a battery cell where, by setting the dimension of the first thickened portion along the first direction to be greater than the dimension of the first body portion along the first direction, the risk of cracking at the connection between the first wall and the end cap can be reduced, increasing the connection stability between the first wall and the end cap. Since the first thickened portion passes through the mid-section of the first wall, which is perpendicular to the second direction, and the distances from the mid-section along the second direction to both ends of the first wall are equal, the expansion amount of the electrode assembly corresponding to the first thickened portion along the first direction is greater than the expansion amount of the electrode assembly corresponding to the second thickened portion. Therefore, this application, by setting the dimension of the first thickened portion along the third direction to be greater than the dimension of the second thickened portion along the third direction, reduces the risk of cracking at the connection between the housing and the end cap, which is most prone to cracking, further increasing the connection stability between the housing and the end cap.

[0109] The technical solutions described in the embodiments of this application are applicable to electrode assemblies, battery cells including electrode elements, batteries including battery cells, and electrical devices using batteries.

[0110] 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.

[0111] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0112] Please refer to Figure 1 , Figure 1This is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0113] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0114] Please refer to Figure 2 , Figure 2 This is an exploded view of the apparatus provided in some embodiments of this application. The battery device 100 includes a battery housing and battery cells 20. In some embodiments, the battery housing may include a top cover 10 and a housing 30, with the top cover 10 and housing 30 covering each other, and the top cover 10 and housing 30 together defining a receiving cavity for receiving the battery cells 20. The housing 30 may be a hollow structure with one end open, and the top cover 10 may be a plate-like structure, with the top cover 10 covering the open side of the housing 30 so that the top cover 10 and housing 30 together define the receiving cavity; the top cover 10 and housing 30 may also be hollow structures with one side open, with the open side of the top cover 10 covering the open side of the housing 30. Of course, the battery housing formed by the top cover 10 and housing 30 can be of various shapes, such as a cylinder, a cuboid, etc.

[0115] Figure 3 This is a schematic diagram of the structure of a battery module according to some embodiments of this application. In the battery device 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the whole assembly of multiple battery cells 20 is housed in a housing. Of course, the battery device 100 can also be in the form of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form a battery module 400, and then multiple battery modules 400 are connected in series, parallel, or in a mixed manner to form a whole and housed in a housing. The battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar component for realizing the electrical connection between multiple battery cells 20.

[0116] Each battery cell 20 can be a secondary battery cell or a primary battery cell; it can also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0117] Figure 4 This is an exploded structural diagram of a battery cell according to some embodiments of this application. The end cap 21 is a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 21 can be adapted to the shape of the housing 22 to fit it. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 21 is less prone to deformation under pressure and impact, enabling the battery cell 20 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 26 can be provided on the end cap 21. The electrode terminals 26 can be used to electrically connect with the electrode assembly 23 for outputting or inputting electrical energy into the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The material of the end cap 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application does not impose special limitations on this. In some embodiments, an insulating element may be provided on the inner side of the end cap 21. The insulating element can be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0118] Figure 5 This is a schematic diagram of the structure of the electrode assembly 23 in some embodiments of this application; Figure 6 This is a schematic diagram of the structure of the housing 22 according to some embodiments of this application; Figure 7 This is a partial cross-sectional schematic diagram of the housing 22 according to some embodiments of this application.

[0119] In a first aspect, embodiments of this application provide a battery cell 20, which includes a housing 22, an end cap 21, and an electrode assembly 23. The housing 22 has an opening 22a; the end cap 21 covers the opening 22a; and the electrode assembly 23 is disposed inside the housing 22. The housing 22 includes two first walls 221 disposed opposite each other in a first direction X, where X is the thickness direction of the electrode assembly 23. At least one first wall 221 includes a first body portion 222 and a first thickened portion 223. The first thickened portion 223 is connected to the first body portion 222 and welded to the end cap 21. Along the first... In one direction X, the size of the first thickened portion 223 is larger than the size of the first body portion 222; the first thickened portion 223 includes a first thickened sub-portion 224 and a second thickened sub-portion 225 arranged along the second direction Y. The first thickened sub-portion 224 passes through the mid-section W of the first wall 221. The mid-section W is perpendicular to the second direction Y. The distance from the mid-section W to both ends of the first wall 221 along the second direction Y is equal. In the third direction Z, the size of the first thickened sub-portion 224 is larger than the size of the second thickened sub-portion 225. The third direction Z is the thickness direction of the end cap 21. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0120] The electrode assembly 23 can be a wound or stacked structure, and the shape of the electrode assembly 23 can be a cuboid. The housing 22 matches the shape of the electrode assembly 23 and is also a cuboid.

[0121] The first wall 221 is the side wall of the housing 22. The first thickening portion 223 can be provided on both first walls 221, or the first thickening portion 223 can be provided on only one first wall 221. The first direction X is the thickness direction of the electrode assembly 23, the second direction Y is the width direction of the electrode assembly 23, and the third direction Z is the height direction of the electrode assembly 23.

[0122] Because the electrode assembly 23 expands during operation, the expansion force along the first direction X is relatively large, making the weld between the housing 22 and the end cap 21 prone to cracking. Therefore, in this embodiment, the size of the first thickened portion 223 along the first direction X is set to be larger than the size of the first body portion 222, that is, the thickness of the first thickened portion 223 is greater than the thickness of the first body portion 222, making the first thickened portion 223 stronger and less prone to cracking at the weld connection with the end cap 21.

[0123] It should be noted that the thickness of the first thickened portion 223 refers to the average thickness of the first thickened portion 223, and the thickness of the first body portion 222 refers to the average thickness of the first body portion 222. Taking the measurement of the thickness of the first thickened portion 223 as an example, during measurement, N points can be selected in the first thickened portion 223, and the thickness of the first thickened portion at each of the N points can be measured. Then, the average thickness of the thickness of the first thickened portion at the N points can be calculated, and this average thickness can be used as the thickness of the first thickened portion 223. When measuring the thickness of the first body portion 222, N points can be selected in the first body portion 222, and the average thickness of the first body portion 222 at the N points can be calculated, and this average thickness can be used as the thickness of the first body portion 222. Here, N is a positive integer. For example, N is 8, 10, or 12, etc. Figure 7 For example, D1 is the thickness of a certain point in the first thickened part 223, and D2 is the thickness of a certain point in the first body part 222.

[0124] The thickness of the first thickened portion 223 and the thickness of the first body portion 222 can be measured using calipers, micrometers, or ultrasonic thickness gauges. For example, calipers can include vernier calipers and digital calipers. The vernier caliper's jaws are perpendicular to the surface being measured, gently clamping the measuring point, and the value on the vernier caliper is read. The principle of a digital caliper is similar to that of a vernier caliper, but a digital caliper directly displays the measurement result on a digital display screen, making it more convenient and accurate to read. An ultrasonic thickness gauge is an instrument that uses the principle of ultrasonic pulse reflection to measure thickness. When the ultrasonic probe contacts the surface of the object being measured, the ultrasonic waves propagate inside the object, reflect back from the bottom surface, and the thickness is calculated based on the propagation speed and round-trip time of the ultrasonic waves in the material.

[0125] It is understood that the mid-section W of the electrode assembly 23 along the second direction Y refers to a section perpendicular to the second direction Y and symmetrically arranged along this mid-section W. The closer to the mid-section W of the electrode assembly 23 along the second direction Y, the greater the probability of expansion deformation. Therefore, the closer to the mid-section W of the electrode assembly 23 along the second direction Y, the more prone the weld between the housing 22 and the end cap 21 is to crack. The first thickened sub-part 224 passes through the mid-section W of the first wall 221, that is, the first thickened sub-part 224 intersects with the mid-section W. In this embodiment, in the third direction Z, the size of the first thickened sub-part 224 is set to be larger than the size of the second thickened sub-part 225, that is, the width of the first thickened sub-part 224 is greater than the width of the second thickened sub-part 225. The first thickened sub-part 224 can resist a greater expansion deformation force of the electrode assembly 23 relative to the second thickened sub-part 225.

[0126] The width H1 of the first thickened sub-part 224 refers to the average width of the first thickened sub-part 224, and the width H2 of the second thickened sub-part 225 refers to the average width of the second thickened sub-part 225. Taking the measurement of the width of the first thickened sub-part 224 as an example, during measurement, N points can be selected in the first thickened sub-part 224, and the width of the first thickened sub-part at each of the N points can be measured. Then, the average thickness of the first thickened sub-part at the N points is calculated, and this average is used as the width of the first thickened sub-part 224. When measuring the width of the second thickened sub-part 225, N points can be selected in the second thickened sub-part 225, and the average width of the second thickened sub-part 225 at the N points can be calculated, and this average is used as the width of the second thickened sub-part 225. Here, N is a positive integer. For example, N is 8, 10, or 12, etc. Figure 8 For example, H1 is the width of a point on the first thickened sub-section 224, and H2 is the width of a point on the second thickened sub-section 225. Similarly, the widths of the first thickened sub-section 224 and the second thickened sub-section 225 can also be measured using calipers, micrometers, or ultrasonic thickness gauges.

[0127] The second thickened sub-parts 225 can be provided on both sides of the first thickened sub-part 224 along the second direction Y, or the second thickened sub-part 225 can be provided only on one side of the first thickened sub-part 224 along the second direction Y.

[0128] In the above solution, by setting the dimension of the first thickened portion 223 along the first direction X to be larger than the dimension of the first body portion 222 along the first direction X, the risk of cracking at the connection position between the first wall 221 and the end cap 21 can be reduced, and the connection stability between the first wall 221 and the end cap 21 can be increased. Since the first thickened sub-portion 224 passes through the mid-section W, the expansion amount of the portion of the electrode assembly 23 corresponding to the first thickened sub-portion 224 along the first direction X is greater than the expansion amount of the portion of the electrode assembly 23 corresponding to the second thickened sub-portion 225. Therefore, in this embodiment, by setting the dimension of the first thickened sub-portion 224 along the third direction Z to be larger than the dimension of the second thickened sub-portion 225 along the third direction Z, the risk of cracking at the connection position between the housing 22 and the end cap 21, which is most prone to cracking, is reduced, and the connection stability between the housing 22 and the end cap 21 is further increased.

[0129] In some embodiments, the first thickened portion 223 includes two second thickened sub-portions 225, which are respectively connected to the two ends of the first thickened sub-portion 224 along the second direction Y.

[0130] The two second thickened sub-sections 225 can be arranged symmetrically relative to the first thickened sub-section 224, or they can be designed differently according to the internal structure of the housing 22.

[0131] The first thickened sub-part 224 and two second thickened sub-parts 225 can be provided on both first walls 221, and the thickening structure of the two first walls 221 can also be symmetrically arranged, or the first thickened sub-part 224 and the second thickened sub-part 225 of the two first walls 221 can be asymmetrically designed.

[0132] The expansion of the electrode assembly 23 along the first direction X exhibits a gradient distribution with a high center and a low edge. The first thickened sub-section 224 is located in the high expansion region, and the second thickened sub-sections 225 on both sides act as stress diffusion layers, transferring concentrated stress to the edge of the shell 22 and reducing the stress peak in the central region.

[0133] In the above solution, by providing second thickened sub-parts 225 on both sides of the first thickened sub-part 224, the range of the first thickened part 223 is increased, further increasing the connection stability between the first wall 221 and the end cap 21.

[0134] In some embodiments, the first thickened portion 223 is symmetrically arranged in the mid-section W along the second direction Y.

[0135] In the above scheme, the symmetrical structure allows the stress generated when the electrode assembly 23 expands along the first direction X to be evenly distributed to the first thickened portion 223, avoiding the risk of cracking caused by local stress concentration. Since the first thickened sub-portion 224 is close to the mid-section W and has a large expansion amount, the symmetrical design can balance the forces on both sides and improve the overall deformation resistance.

[0136] In some embodiments, the second thickened sub-part 225 extends to the edge of the first wall 221 along the second direction Y.

[0137] One end of the second thickened sub-part 225 along the second direction Y is connected to the first thickened sub-part 224, and the other end is connected to the other side wall of the housing 22, so that all areas of the first wall 221 near the opening 22a along the second direction Y can be thickened.

[0138] In the above scheme, by covering the edge of the first wall 221 with the thickened area, the stress generated by the expansion of the electrode assembly 23 along the second direction Y can be transferred from the center to the edge, reducing the risk of local cracking caused by stress concentration at the edge.

[0139] In some embodiments, at least a portion of the first thickened sub-portion 224 protrudes from the second thickened sub-portion 225 in the direction from the electrode assembly 23 to the end cap 21.

[0140] The first thickened sub-part 224 protrudes upward relative to the second thickened sub-part 225, allowing the electrode tab 232 to be positioned on the electrode assembly 23 at the location corresponding to the protruding first thickened sub-part 224. The electrode tab 232 can be bent and accommodated within the space corresponding to the first thickened sub-part 224. The electrode terminal 212 is positioned on the end cap 21 at the location corresponding to the second thickened sub-part 225, and the electrode tab 232 is connected to the electrode terminal 212 via the adapter 233.

[0141] The shape of the electrode assembly 23 can also be set to match the shape of the first thickened sub-part 224 and the second thickened sub-part 225. For example, after being wound or stacked, the upper end of the electrode assembly 23 also protrudes upward at the position of the first thickened sub-part 224 and is also recessed downward at the position of the second thickened sub-part 225.

[0142] In the above scheme, by setting the first thickened sub-part 224 to protrude from the second thickened sub-part 225, more of the structure of the electrode assembly 23 can be accommodated at the position of the first thickened sub-part 224, thereby increasing the energy density of the battery cell 20.

[0143] In some embodiments, the end of the first thickened sub-part 224 near the first body part 222 is flush with the end of the second thickened sub-part 225 near the first body part 222.

[0144] That is, the lower end of the first thickened sub-part 224 is flush with the lower end of the second thickened sub-part 225, while the upper end of the first thickened sub-part 224 protrudes relative to the upper end of the second thickened sub-part 225.

[0145] In the above scheme, the first thickened sub-part 224 and the second thickened sub-part 225 form a continuous transition in the region near the first body part 222, which to a certain extent avoids stress concentration points caused by abrupt changes in thickness.

[0146] like Figure 9 As shown, in some embodiments, the electrode assembly 23 points in the direction of the end cap 21, and the second thickened sub-part 225 protrudes from the first thickened sub-part 224.

[0147] The second thickened sub-part 225 protrudes upward relative to the first thickened sub-part 224, allowing the electrode tab 232 to be positioned on the electrode assembly 23 at the location corresponding to the protruding second thickened sub-part 225. The electrode tab 232 can be bent and accommodated within the space corresponding to the second thickened sub-part 225. The electrode terminal 212 is positioned on the end cap 21 at the location corresponding to the first thickened sub-part 224, and the electrode tab 232 is connected to the electrode terminal 212 via the adapter 233.

[0148] The shape of the electrode assembly 23 can also be set to match the shape of the first thickened sub-part 224 and the second thickened sub-part 225. For example, after being wound or stacked, the upper end of the electrode assembly 23 also protrudes upward at the position of the second thickened sub-part 225 and is also recessed downward at the position of the first thickened sub-part 224.

[0149] In the above scheme, by setting the first thickened sub-part 224 to protrude from the second thickened sub-part 225, more of the structure of the electrode assembly 23 can be accommodated at the position of the first thickened sub-part 224, thereby increasing the energy density of the battery cell 20.

[0150] In some embodiments, the first wall 221 is provided with a recess 226, the recess 226 penetrating the first wall 221 along a first direction X; the first thickened portion 223 is provided at least corresponding to the recess 226; there are two second thickened sub-portions 225, the two second thickened sub-portions 225 are respectively located on both sides of the recess 226.

[0151] For example, both the positive and negative electrodes can be located beside the first thickened sub-part 224. The electrode terminal 212 connected to the positive electrode is located on the second thickened sub-part 225 to the left of the first thickened sub-part 224, and the negative electrode terminal connected to the negative electrode is located on the second thickened sub-part 225 to the right of the first thickened sub-part 224. After the positive electrode is bent, it is electrically connected to the electrode terminal 212 on the side via the adapter 233. After the negative electrode is bent, it is electrically connected to the electrode terminal 212 on the side via the adapter 233.

[0152] In the above solution, by providing a second thickened sub-part 225 on both sides of the recess 226, the concentrated stress can be diffused to both sides. When the electrode assembly 23 expands along the first direction X, the first thickened part 223 increases the material thickness and disperses the stress to a larger area, thereby avoiding failure of the edge of the recess 226 due to local stress overload to a certain extent.

[0153] like Figure 10 As shown, in some embodiments, the end cap 21 includes a cap body 211 and an electrode terminal 212. The cap body 211 includes a first cap portion 213 and a second cap portion 214. The first cap portion 213 is recessed relative to the second cap portion 214 in the direction of the housing 22. The first cap portion 213 is connected to the recess 226. The electrode terminal 212 is disposed on the first cap portion 213.

[0154] That is, the end cap 21 has an irregular shape, which can provide more space for the housing 22 to accommodate the electrode assembly 23.

[0155] In the above scheme, by setting the electrode terminal 212 in the recessed first cover portion 213, the tab 232 and the adapter 233 can be accommodated in the housing 22 position corresponding to the protruding second cover portion 214, thereby improving the energy density of the battery cell 20.

[0156] like Figure 11 As shown, in some embodiments, the electrode assembly 23 includes an electrode body 231 and a tab 232. The battery cell 20 also includes an adapter 233 for connecting the tab 232 and the electrode terminal 212. The tab 232 and the adapter 233 are welded together to form a solder mark. The projection of the solder mark along the thickness direction at least partially overlaps with the projection of the first thickened portion 223 along the first direction X.

[0157] The tab 232 and the adapter 233 can be welded by laser or ultrasonic welding. The solder mark of the tab 232 and the adapter 233 corresponds to the first thickened portion 223. The bottom end of the solder mark may be higher than the bottom end of the first thickened portion 223; or the bottom end of the solder mark may be lower than the bottom end of the first thickened portion 223, but the top end of the solder mark may be higher than the bottom end of the first thickened portion 223.

[0158] In the above solution, by setting the solder mark formed by the tab 232 and the adapter 233 to correspond with the first thickened part 223, the internal space of the housing 22 can be saved and the energy density of the battery cell 20 can be increased.

[0159] In some embodiments, along the third direction Z, the solder mark is closer to the end cap 21 on the side of the first thickened portion 223 away from the opening 22a, that is, the bottom end of the solder mark is higher than the bottom end of the first thickened portion 223.

[0160] In the above solution, by placing the solder mark closer to the end cap 21 relative to the first thickened portion 223, the internal space of the housing 22 can be further saved, and the energy density of the battery cell 20 can be further improved.

[0161] like Figure 12 As shown, in some embodiments, at least a portion of the first thickened sub-portion 224 protrudes beyond the second thickened sub-portion 225 in the direction from the end cap 21 toward the electrode assembly 23.

[0162] The lower end of the first thickened sub-part 224 protrudes downward relative to the lower end of the second thickened sub-part 225.

[0163] In the above scheme, by making at least a portion of the first thickened sub-part 224 protrude relative to the second thickened sub-part 225 in a direction away from the end cap 21, the size of the first thickened sub-part 224 along the third direction Z is greater than the size of the second thickened sub-part 225 along the third direction Z, which directly enhances the structural strength of the region with the largest expansion of the electrode assembly 23.

[0164] In some embodiments, the end of the second thickened sub-part 225 away from the first body part 222 is flush with the end of the first thickened sub-part 224 away from the first body part 222.

[0165] In the above solution, by setting the upper ends of the first thickened sub-part 224 and the second thickened sub-part 225 to be flush, the end cap 21 can be made easier to manufacture and the manufacturing difficulty can be reduced.

[0166] like Figure 13 As shown, in some embodiments, the first thickened portion 223 further includes a third thickened sub-portion 227, which is connected between the first thickened sub-portion 224 and the second thickened sub-portion 225; along the direction from the first thickened sub-portion 224 to the second thickened sub-portion 225, the size of the third thickened sub-portion 227 gradually decreases in the third direction Z.

[0167] The third thickened sub-part 227 is located between the first thickened sub-part 224 and the second thickened sub-part 225, and the third thickened sub-part 227 is a transitional connection portion between the first thickened sub-part 224 and the second thickened sub-part 225.

[0168] In the above scheme, the first thickened sub-part 224 and the second thickened sub-part 225 are connected by the third thickened sub-part 227. The third thickened sub-part 227 serves as a transition region, and its size gradually decreases along the third direction Z. This makes the stiffness change between the first thickened sub-part 224 and the second thickened sub-part 225 smoother and reduces stress concentration points caused by abrupt changes in thickness.

[0169] In some embodiments, the dimension of the third thickened sub-part 227 along the third direction Z at the end near the first thickened sub-part 224 is equal to the dimension of the first thickened sub-part 224 along the third direction Z, and the dimension of the third thickened sub-part 227 along the third direction Z at the end near the second thickened sub-part 225 is equal to the dimension of the second thickened sub-part 225 along the third direction Z.

[0170] In the above scheme, a continuous transition is formed between the third thickened sub-part 227 and the first thickened sub-part 224 and the second thickened sub-part 225, eliminating stress concentration points caused by sudden changes in thickness, further reducing the risk of cracking at the connection position between the shell 22 and the end cap 21 which is most prone to cracking, and further increasing the connection stability between the shell 22 and the end cap 21.

[0171] like Figure 14As shown, in some embodiments, the first wall 221 further includes a first transition portion 228, which connects the first body portion 222 and the first thickened portion 223 in the third direction Z; the thickness of the first transition portion 228 gradually decreases along the direction from the first thickened portion 223 to the first body portion 222.

[0172] In the above solution, by making the stiffness change between the first thickened portion 223 and the first body portion 222 more gradual, stress concentration points caused by abrupt changes in thickness are eliminated. When the electrode assembly 23 expands along the first direction X, the stress is gradually dispersed from the first thickened portion 223 to the first body portion 222 through the first transition portion 228, which to a certain extent avoids the formation of stress peaks at the interface, thereby reducing the risk of cracking.

[0173] like Figure 15 As shown, in some embodiments, the housing 22 further includes two second walls 229 disposed opposite each other along the second direction Y, wherein the area of ​​the first wall 221 is larger than the area of ​​the second wall 229.

[0174] The first wall 221 is a sidewall with a larger area, and the second wall 229 is a sidewall with a smaller area. Since the electrode assembly 23 has a greater expansion deformation force along the first direction X, the connection between the first wall 221 and the end cap 21 is thickened first.

[0175] In the above scheme, the first thickened part 223 is set in the first wall 221 with a larger area to enhance its rigidity and strength, which can resist the expansion and deformation trend caused by the large area, making it less likely for the more cracked position to deform and crack.

[0176] In some embodiments, at least one of the second walls 229 includes a second body portion 2291 and a second thickened portion 2292, the second thickened portion 2292 being connected to the second body portion 2291 and welded to the end cap 21, and the size of the second thickened portion 2292 being larger than the size of the second body portion 2291 along the first direction X.

[0177] In this embodiment, not only is the end of the first wall 221 thickened, but the connection between the second wall 229 and the end cap 21 is also thickened. The structure of the second thickened portion 2292 can refer to the structure of the first thickened portion 223, and will not be described again here.

[0178] In the above solution, by thickening the part where the second wall 229 is welded to the end cap 21, the entire welded position between the housing 22 and the end cap 21 can be reinforced, further increasing the connection stability between the end cap 21 and the housing 22.

[0179] In some embodiments, the thickness difference between the first thickened portion 223 and the first body portion 222 is L, where L satisfies: 0.05mm≤L≤0.5mm.

[0180] "Thickness difference between the first thickened portion 223 and the first body portion 222" refers to the difference between the average thickness of the first thickened portion 223 and the average thickness of the first body portion 222.

[0181] When the average thickness of the first thickened portion 223 is greater than the average thickness of the first body portion 222 by a certain value (i.e., the thickness difference L), the first thickened portion 223 is structurally equivalent to receiving additional reinforcement. For example, inside the battery cell 20, the electrode assembly 23 may undergo volume changes during charging and discharging, generating an outward expansion force on the casing 22. As a key part connecting the end cap 21, the first thickened portion 223 bears a large stress concentration. A suitable thickness difference L gives the first thickened portion 223 higher rigidity and resistance to deformation, enabling it to more effectively resist these internal forces and, to a certain extent, ensure that the first thickened portion 223 will not easily deform or crack.

[0182] The thickness difference between the first thickened portion 223 and the first body portion 222 is greater than or equal to 0.05 mm. The first thickened portion 223 is thicker than the first body portion 222, which can cope with the influence of complex working conditions such as vibration, impact and internal stress in actual use. It can play a role in strengthening the first thickened portion 223 and can ensure the stability of the connection between the shell 22 and the end cover 21 to a certain extent.

[0183] During the manufacturing process of the housing 22, if a mold forming process (such as injection molding or die casting) is used, the mold usually has a certain draft angle requirement so that the formed part can be smoothly removed from the mold. The thickness difference between the first thickened part 223 and the first body part 222 is less than or equal to 0.5mm, which will not cause the first thickened part 223 to form a large protrusion or step in the mold. This allows the draft angle to be set reasonably, reducing the resistance and difficulty of demolding. During demolding, it will not cause damage to the first thickened part 223 or other parts of the housing 22, and will not affect the product yield.

[0184] The thickness difference L between the first thickened portion 223 and the first body portion 222 can be any value between 0.05mm and 0.5mm. For example, L can be 0.05mm, 0.07mm, 0.09mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, or 0.5mm.

[0185] In the above solution, by limiting the thickness difference L between the first thickened portion 223 and the first body portion 222 to a suitable range, the strengthening effect of the first thickened portion 223 can be satisfied without affecting the mold demolding of the shell 22, thus reducing the processing difficulty.

[0186] In some embodiments, L satisfies: 0.1mm≤L≤0.3mm.

[0187] The thickness difference L between the first thickened portion 223 and the first body portion 222 can be any value between 0.1mm and 0.3mm. For example, L can be 0.1mm, 0.15mm, 0.2mm, 0.22mm, 0.25mm, 0.26mm, 0.28mm, or 0.3mm.

[0188] In the above solution, by further limiting the range of the thickness difference L between the first thickened portion 223 and the first body portion 222, the strengthening effect of the first thickened portion 223 can be further improved, and the processing difficulty can be further reduced.

[0189] In some embodiments, the minimum width of the first thickened portion 223 along the height direction Z of the battery cell 20 is H, where H satisfies: 1mm≤H≤10mm.

[0190] The minimum width H of the first thickened portion 223 can be any value between 1mm and 10mm. For example, H can be 1mm, 0.15mm, 0.2mm, 0.22mm, 0.25mm, 0.26mm, 0.28mm, or 10mm.

[0191] The minimum width of the first thickened portion 223 along the height direction Z of the battery cell 20 is the narrowest width of the first thickened portion 223. H is greater than or equal to 1mm, so the first thickened portion 223 is not relatively narrow. From the perspective of material mechanics, when it is subjected to external forces perpendicular to the plane of the opening 221 (such as the force generated inside the battery due to the expansion of the electrode assembly 23 or external impact), it can more effectively concentrate stress, so that the material of the first thickened portion 223 itself can fully exert its tensile and compressive strength.

[0192] H is less than or equal to 10mm. The first thickened part 223 is similar to a robust frame structure, which can not only resist the impact of external forces from all directions, but also provide more stable support for the end cover 21. Even under complex and harsh working conditions, such as strong vibration or collision environments, it can still ensure the integrity of the overall structure of the battery cell 20, and to a certain extent prevent the first thickened part 223 from cracking, deforming and other problems that weaken the connection strength.

[0193] The minimum width H of the first thickened portion 223 can be measured using the height direction Z of the battery cell 20 as the measurement plane. It can be measured using vernier calipers or digital calipers, or using an optical microscope and image analysis software. Since the width of the first thickened portion 223 may vary in the circumferential direction, it is necessary to measure it at multiple locations along the circumference of the first thickened portion 223. For example, the circumference of the first thickened portion 223 can be divided into several equal parts (e.g., 8, 10, etc.), and the minimum width and thickness can be measured in the height direction Z corresponding to each part. Then, all measured values ​​are compared, and the smallest value is determined as the minimum width H of the first thickened portion 223 along the height direction Z.

[0194] In the above solution, by setting the minimum width H of the first thickened portion 223 within a suitable range, the strengthening effect of the first thickened portion 223 can be guaranteed to a certain extent without affecting the energy density of the battery cell 20.

[0195] In some embodiments, H satisfies: 3mm ≤ H ≤ 8mm.

[0196] The minimum width H of the first thickened portion 223 can be any value between 3mm and 8mm. For example, H can be 3mm, 4mm, 5mm, 6mm, 6.5mm, 7.5mm, 7.8mm, or 8mm.

[0197] In the above solution, by further limiting the range of the minimum width H of the first thickened portion 223, the strengthening effect of the first thickened portion 223 can be further improved, and the impact on the energy density of the battery cell 20 can be further reduced.

[0198] Secondly, embodiments of this application also provide a battery device 100, including a battery cell 20 of any of the above embodiments.

[0199] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery device 100, which is used to provide electrical energy.

[0200] According to some embodiments of this application, this application provides a battery cell 20, which includes a housing 22, an end cap 21, and an electrode assembly 23. The housing 22 has an opening 22a; the end cap 21 covers the opening 22a; the electrode assembly 23 is disposed inside the housing 22; wherein, the housing 22 includes two first walls 221 disposed opposite each other in a first direction X, the first direction X being the thickness direction of the electrode assembly 23, at least one of the first walls 221 including a first body portion 222 and a first thickened portion 223, the first thickened portion 223 being connected to the first body portion 222, and the first thickened portion 223 being welded to the end cap 21, along the thickness direction of the electrode assembly 23. In the first direction X, the size of the first thickened portion 223 is larger than the size of the first body portion 222. The first thickened portion 223 includes a first thickened sub-portion 224 and a second thickened sub-portion 225 arranged along the second direction Y. The first thickened sub-portion 224 passes through the mid-section W of the first wall 221, and the mid-section W is perpendicular to the second direction Y. The distances from the mid-section W to both ends of the first wall 221 along the second direction Y are equal. In the third direction Z, the size of the first thickened sub-portion 224 is larger than the size of the second thickened sub-portion 225. The third direction Z is the thickness direction of the end cap 21. The first direction X, the second direction Y, and the third direction Z are all perpendicular to each other. The first thickened portion 223 includes two second thickened sub-portions 225, which are respectively connected to both ends of the first thickened sub-portion 224 along the second direction Y.

[0201] The battery device 100 provided according to the embodiments of this application includes the battery cell 20 provided in the embodiments. Since the battery device 100 provided in the embodiments of this application adopts the battery cell 20 provided in the above embodiments, it has the same technical effect, which will not be repeated here.

[0202] The electrical device provided according to the embodiments of this application includes the battery device 100 provided in the above embodiments, and the battery device 100 is used to provide electrical energy.

[0203] The power supply device provided according to the embodiments of this application has the same technical effect as the battery device 100 provided in the embodiments of this application, and will not be described again here.

[0204] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The shell has an opening; An end cap is provided over the opening; At least one electrode assembly is disposed inside the housing; The housing includes two first walls disposed opposite each other in a first direction, the first direction being the thickness direction of the electrode assembly. At least one first wall includes a first body portion and a first thickened portion. The first thickened portion is connected to the first body portion and welded to the end cap. Along the first direction, the size of the first thickened portion is larger than the size of the first body portion. The first thickened portion includes a first thickened sub-part and a second thickened sub-part arranged along a second direction. The first thickened sub-part passes through the mid-section of the first wall. The mid-section is perpendicular to the second direction. The distance from the mid-section to both ends of the first wall along the second direction is equal. In a third direction, the size of the first thickened sub-part is larger than the size of the second thickened sub-part. The third direction is the thickness direction of the end cap. The first direction, the second direction, and the third direction are perpendicular to each other.

2. The battery cell according to claim 1, characterized in that, The first thickened portion includes two second thickened sub-portions, which are respectively connected to the two ends of the first thickened sub-portion along the second direction.

3. The battery cell according to claim 2, characterized in that, The first thickened portion is symmetrically arranged in the mid-section along the second direction.

4. The battery cell according to claim 2, characterized in that, The second thickened sub-section extends to the edge of the first wall along the second direction.

5. The battery cell according to any one of claims 1-4, characterized in that, Along the direction from the electrode assembly to the end cap, at least a portion of the first thickened sub-part protrudes beyond the second thickened sub-part.

6. The battery cell according to claim 5, characterized in that, The end of the first thickened sub-part near the first body part is flush with the end of the second thickened sub-part near the first body part.

7. The battery cell according to any one of claims 1-4, characterized in that, Along the direction from the electrode assembly to the end cap, the second thickened sub-part protrudes from the first thickened sub-part.

8. The battery cell according to claim 7, characterized in that, The first wall has a recess, and the recess extends through the first wall in a first direction; The first thickened portion is provided at least corresponding to the recessed portion; There are two second thickened sub-parts, which are located on both sides of the recess.

9. The battery cell according to claim 8, characterized in that, The end cap includes a cap body and an electrode terminal. The cap body includes a first cap portion and a second cap portion. The first cap portion is recessed relative to the second cap portion in the direction of the housing. The first cap portion is connected to the recess. The electrode terminal is disposed on the first cap portion.

10. The battery cell according to claim 9, characterized in that, The electrode assembly includes an electrode body and a tab. The battery cell also includes an adapter for connecting the tab to an electrode terminal. The tab and the adapter are welded together to form a solder mark. The projection of the solder mark along the thickness direction at least partially overlaps with the projection of the first thickened portion along the first direction.

11. The battery cell according to claim 10, characterized in that, Along the third direction, the solder mark is closer to the end cap on the side opposite to the opening of the first thickened portion.

12. The battery cell according to any one of claims 1-4, characterized in that, Along the direction from the end cap toward the electrode assembly, at least a portion of the first thickened sub-part protrudes beyond the second thickened sub-part.

13. The battery cell according to claim 12, characterized in that, The end of the second thickened sub-part that is away from the first body part is flush with the end of the first thickened sub-part that is away from the first body part.

14. The battery cell according to claim 1, characterized in that, The first thickened portion further includes a third thickened sub-portion, which is connected between the first thickened sub-portion and the second thickened sub-portion; Along the direction from the first thickened sub-part to the second thickened sub-part, the size of the third thickened sub-part gradually decreases in the third direction.

15. The battery cell according to claim 14, characterized in that, The dimension of the third thickened sub-part near the first thickened sub-part along the third direction is equal to the dimension of the first thickened sub-part along the third direction, and the dimension of the third thickened sub-part near the second thickened sub-part along the third direction is equal to the dimension of the second thickened sub-part along the third direction.

16. The battery cell according to claim 1, characterized in that, The first wall also includes a first transition portion, which connects the first body portion and the first thickened portion in the third direction. Along the direction from the first thickened portion to the first body portion, the thickness of the first transition portion gradually decreases.

17. The battery cell according to any one of claims 1-16, characterized in that, The housing also includes two second walls disposed opposite each other along the second direction, wherein the area of ​​the first wall is larger than the area of ​​the second wall.

18. The battery cell according to claim 17, characterized in that, At least one of the second walls includes a second body portion and a second thickened portion, the second thickened portion being connected to the second body portion and welded to the end cap, and the size of the second thickened portion being larger than the size of the second body portion along the first direction.

19. The battery cell according to any one of claims 1-18, wherein, The thickness difference between the first thickened portion and the first body portion is L, and L satisfies: 0.05mm≤L≤0.5mm.

20. The battery cell according to claim 19, wherein, The L satisfies: 0.1mm≤L≤0.3mm.

21. The battery cell according to any one of claims 1-20, wherein, Along the height direction of the battery cell, the minimum width of the first thickened portion is H, where H satisfies: 1mm≤H≤10mm.

22. The battery cell according to claim 21, wherein, The condition H satisfies: 3mm ≤ H ≤ 8mm.

23. A battery device, wherein, Includes the battery cell according to any one of claims 1-22.

24. An electrical appliance, wherein, Includes the battery device according to claim 23, the battery device being used to provide electrical energy.

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