Battery cell, battery and electrical apparatus

Abstract

A battery cell, a battery and an electrical apparatus, relating to the technical field of batteries. The battery cell comprises a housing, a first terminal and a second terminal. The first terminal comprises a first penetrating part arranged on the housing in a penetrating mode, and a first inner fixing part and a first outer fixing part which are connected to the first penetrating part and arranged on the inner side and the outer side of the housing respectively. The second terminal comprises a second penetrating part arranged on the housing in a penetrating mode, and a second inner fixing part and a second outer fixing part which are connected to the second penetrating part and arranged on the inner side and the outer side of the housing respectively. The material strength of the first inner fixing part is smaller than the material strength of the second inner fixing part, and the wall thickness of the first inner fixing part is larger than the wall thickness of the second inner fixing part.

Description

Battery cells, batteries and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 202420166101.5 and application date 2024-01-23, and claims the priority of the above-mentioned Chinese patent application. The entire content of the above-mentioned Chinese patent application is hereby introduced into this application as a reference. Technical Field

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

[0004] In recent years, new energy vehicles have experienced rapid development. In the electric vehicle sector, power batteries, as the power source of electric vehicles, play an irreplaceable and important role. Power batteries consist of several battery cells, but achieving a balance between reliability and cost is difficult.

[0005] Summary of the Invention

[0006] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can achieve both reliability and low cost of the battery cell.

[0007] In a first aspect, an embodiment of the present application provides a battery cell, comprising: a shell, a first pole and a second pole, the first pole comprising a first penetration portion passing through the shell, and a first inner fixing portion and a first outer fixing portion connected to the first penetration portion and respectively arranged on the inner and outer sides of the shell, the second pole comprising a second penetration portion passing through the shell, and a second inner fixing portion and a second outer fixing portion connected to the second penetration portion and respectively arranged on the inner and outer sides of the shell, the material strength of the first inner fixing portion is less than the material strength of the second inner fixing portion, and the wall thickness of the first inner fixing portion is greater than the wall thickness of the second inner fixing portion.

[0008] In the above technical solution, since the capacity of the battery cell can be determined by the wall thickness of the first fixing portion (of relatively weak material strength), this application sets the wall thickness of the second inner fixing portion (of relatively strong material strength) to be smaller than that of the first inner fixing portion (of relatively weak material strength). This allows the second inner fixing portion to be thinner without affecting the capacity of the battery cell or the withstand voltage level of the second terminal, thereby reducing the material cost and weight of the second terminal. At the same time, because the wall thickness of the first inner fixing portion (of relatively weak material strength) is greater than that of the second inner fixing portion (of relatively strong material strength), the withstand voltage level of the first terminal also meets the requirements.

[0009] In some embodiments, the first penetration portion defines a first accommodating groove, which is open toward the inner side or outer side of the shell. The first penetration portion includes a first end wall portion arranged opposite to the opening of the first accommodating groove. The first internal fixing portion is made of the same main body material as the first end wall portion, and the wall thickness of the first end wall portion is greater than the wall thickness of the first internal fixing portion.

[0010] In the above technical solution, by setting the wall thickness of the first end wall of the first terminal to be greater than the wall thickness of the first inner fixing portion, this is equivalent to increasing the wall thickness at the center of the first terminal while meeting the pressure resistance level at the edge of the first terminal. This allows the center of the first terminal, despite its larger area, to exhibit better structural strength, thereby improving the reliability of the first terminal. Alternatively, by setting the wall thickness of the first inner fixing portion to be less than the wall thickness of the first end wall of the first terminal, this is equivalent to reducing the wall thickness at the edge of the first terminal while meeting the structural strength at the center of the first terminal. This can save material, reduce costs, and reduce the height space occupied by the edge of the first terminal within the housing, thereby increasing the capacity of the battery cell.

[0011] In some embodiments, a first through hole is formed on the first end wall portion, connecting the inner side of the shell and the first receiving groove. The battery cell assembly of the battery cell includes a first conductive part electrically connected to the first pole. The first conductive part is passed through the first through hole and includes a first connecting section received in the first receiving groove. The first connecting section is overlapped on the first end wall portion and welded to the first end wall portion.

[0012] In the above technical solution, the first through hole is provided so that the first conductive part extends into the first accommodating groove. The first accommodating groove can accommodate the first conductive part, reduce the height space occupied by the first conductive part in the accommodating cavity, and increase the capacity of the battery cell. Moreover, by setting the wall thickness of the first internal fixed part to be smaller than the wall thickness of the first end wall, the relatively thick first end wall can be strengthened to meet the welding penetration and structural strength. At the same time, the relatively thin first internal fixed part is thinned relative to the first end wall. On the premise of meeting the pressure resistance level, the capacity of the battery cell is improved and the material cost is reduced.

[0013] In some embodiments, the first end wall portion is arranged close to the inner side of the shell relative to the first accommodating groove, and the inner end surface of the first inner fixing portion is flush with the inner end surface of the first end wall portion.

[0014] In the above technical solution, by setting the side surface of the first inner fixing portion close to the accommodating cavity to be flush with the side surface of the first end wall portion close to the accommodating cavity, the processing of the first pole can be simplified, the processing difficulty can be reduced, and the production cost can be reduced. Moreover, since the inner end surface of the first end wall portion does not protrude from the inner end surface of the first inner fixing portion in the direction of the accommodating cavity, the height space occupied by the center of the first pole in the shell is reduced, thereby reducing the risk of short circuit between the first pole and the battery cell assembly.

[0015] In some embodiments, the first end wall portion is made of aluminum and has a wall thickness of 2.2 mm to 0.8 mm, and the wall thickness of the first inner fixing portion is 2 mm to 0.8 mm.

[0016] In the above technical solution, the wall thickness of the first end wall portion is not too large, so that the volume of the first accommodating groove is not too small, meeting the storage requirements of the first conductive part; the wall thickness of the first end wall portion is not too small, so that the first end wall portion can meet the welding penetration requirements with the first conductive part and the structural strength requirements of the first end wall portion; the wall thickness of the first internal fixed portion is not too large, thereby reducing the height space occupied by the first internal fixed portion in the accommodating cavity, increasing the capacity of the battery cell, and reducing material costs; the wall thickness of the first internal fixed portion is not too small, thereby meeting the pressure resistance level of the first pole, and improving the problem of the first pole escaping from the shell due to the high pressure in the shell.

[0017] In some embodiments, the wall thickness of the first end wall portion is 2.2 mm, and the wall thickness of the first inner fixing portion is 2 mm.

[0018] In the above technical solution, by setting the wall thickness of the first end wall portion to 2.2 mm and the wall thickness of the first internal fixing portion to 2 mm, the storage requirements for the first conductive portion can be better met, and the first end wall portion can meet the welding penetration requirements with the first conductive portion, as well as the structural strength requirements of the first end wall portion, and the first internal fixing portion occupies a small height space of the accommodating cavity, thereby increasing the capacity of the battery cell and reducing material costs. It can also meet the pressure resistance level of the first pole and improve the problem of the first pole falling out of the shell due to the high pressure inside the shell.

[0019] In some embodiments, the second penetration portion defines a second accommodating groove, which is open toward the inner side or outer side of the shell. The second penetration portion includes a second end wall portion arranged opposite to the opening of the second accommodating groove. The second internal fixing portion is made of the same main material as the second end wall portion, and the wall thickness of the second end wall portion is smaller than the wall thickness of the second internal fixing portion.

[0020] In the above technical solution, by setting the wall thickness of the second end wall of the second pole to be smaller than the wall thickness of the second inner fixing portion, this is equivalent to reducing the wall thickness of the second end wall, which has relatively greater material strength, while still meeting the pressure resistance level at the edge of the second pole. This reduces the material cost of the second pole while still meeting the structural strength of the second end wall, and increases the volume of the second receiving groove. Alternatively, by setting the wall thickness of the second inner fixing portion to be larger than the wall thickness of the second end wall of the second pole, this is equivalent to increasing the wall thickness of the second inner fixing portion while still meeting the structural strength of the second end wall, thereby improving the pressure resistance level of the second pole. Furthermore, because the wall thickness of the second inner fixing portion is smaller than that of the first inner fixing portion, even if the wall thickness of the second inner fixing portion is increased, the height space occupied within the housing will not increase, thereby ensuring the capacity of the battery cell.

[0021] In some embodiments, a second through hole is formed on the second end wall portion, connecting the inner side of the shell and the second receiving groove. The battery cell assembly of the battery cell includes a second conductive portion connected to the second pole. The second conductive portion is passed through the second through hole and includes a second connecting section received in the second receiving groove. The second connecting section is overlapped on the second end wall portion and welded to the second end wall portion.

[0022] In the above technical solution, the second through-hole allows the second conductive portion to extend into the second receiving groove. The second receiving groove can accommodate the second conductive portion, reducing the height space occupied by the second conductive portion in the receiving cavity and increasing the capacity of the battery cell. Furthermore, because the thickness of the second end wall of the second terminal is less than that of the second inner fixing portion, the volume of the second receiving groove can be increased while maintaining a sufficient pressure resistance at the edge of the second terminal. This facilitates greater accommodation of the second conductive portion and facilitates welding of the second connecting section to the second end wall.

[0023] In some embodiments, the second end wall portion is arranged close to the inner side of the shell relative to the second accommodating groove, and the inner end surface of the second inner fixing portion is flush with the inner end surface of the second end wall portion.

[0024] In the above technical solution, by setting the side surface of the second inner fixing portion close to the accommodating cavity to be flush with the side surface of the second end wall portion close to the accommodating cavity, the processing of the second pole can be simplified, the processing difficulty can be reduced, and the production cost can be reduced. Moreover, since the inner end surface of the second end wall portion does not protrude from the inner end surface of the second inner fixing portion in the direction of the accommodating cavity, the height space occupied by the center of the second pole in the shell is reduced, thereby reducing the risk of short circuit between the second pole and the battery cell assembly.

[0025] In some embodiments, the second end wall portion is made of copper and has a wall thickness of 1.3 mm to 0.8 mm, and the wall thickness of the second inner fixing portion is 1.6 mm to 0.8 mm.

[0026] In the above technical solution, the wall thickness of the second end wall portion is not too large, so that the volume of the second accommodating groove is larger, the storage demand for the second conductive part is increased, and the material cost is low. The wall thickness of the second end wall portion is not too small, so that the second end wall portion can meet the welding penetration demand with the second conductive part and the structural strength demand of the second end wall portion. The wall thickness of the second internal fixed portion is not too large, so as to reduce the height space occupied by the second internal fixed portion to the accommodating cavity, increase the capacity of the battery cell, and reduce the material cost. The wall thickness of the second internal fixed portion is not too small, so as to meet the pressure resistance level of the second pole and improve the problem of the second pole escaping from the shell due to the high pressure in the shell.

[0027] In some embodiments, the wall thickness of the second end wall portion is 1.2 mm, and the wall thickness of the second inner fixing portion is 1.5 mm.

[0028] In the above technical solution, the storage requirements for the second conductive part can be better met, and the second end wall can meet the welding penetration requirements with the second conductive part, as well as the structural strength requirements of the second end wall, and reduce the material cost of the second end wall. In addition, the second internal fixing part occupies a small height space of the accommodating cavity, thereby increasing the capacity of the battery cell and reducing the material cost. In addition, the pressure resistance level of the second pole can be met, and the problem of the second pole falling out of the shell due to the high pressure inside the shell can be improved.

[0029] In some embodiments, the first penetration portion defines a first accommodating groove, the first accommodating groove is open toward the inner side or the outer side of the shell, the first penetration portion includes a first end wall portion arranged opposite to the opening of the first accommodating groove, the second penetration portion defines a second accommodating groove, the second accommodating groove is open toward the inner side or the outer side of the shell, the second penetration portion includes a second end wall portion arranged opposite to the opening of the second accommodating groove, wherein the material strength of the first end wall portion is less than the material strength of the second end wall portion, and the wall thickness of the first end wall portion is greater than the wall thickness of the second end wall portion.

[0030] In the above technical solution, since the material strength of the first end wall portion is less than that of the second end wall portion, the first end wall portion is not easily deformed during a simulated inflation process. Furthermore, the second end wall portion of the second pole is also less likely to deform even though its wall thickness is smaller than that of the first end wall portion of the first pole. Therefore, setting the wall thickness of the second end wall portion to be smaller than that of the first end wall portion can effectively increase the volume of the second receiving tank and reduce the material cost and weight of the second pole.

[0031] In some embodiments, the material strength of the first external fixing portion is less than the material strength of the second external fixing portion, and the wall thickness of the first external fixing portion is greater than the wall thickness of the second external fixing portion.

[0032] In the above technical solution, since the material strength of the first external fixing part is less than the material strength of the second external fixing part, when the wall thickness of the first external fixing part makes the structural strength of the first external fixing part meet the requirements, the structural strength requirements of the second external fixing part can also be met by setting the wall thickness of the second external fixing part to be smaller than the wall thickness of the first external fixing part. Therefore, by thinning the second external fixing part relative to the first external fixing part, the material cost and weight of the second pole can be reduced while meeting the structural strength requirements.

[0033] In some embodiments, the shell has a first mounting hole for the first penetration portion to penetrate, the first penetration portion includes a first surrounding wall portion extending along the circumference of the first mounting hole, and a first accommodating groove is formed in the first surrounding wall portion; the shell has a second mounting hole for the second penetration portion to penetrate, the second penetration portion includes a second surrounding wall portion extending along the circumference of the second mounting hole, and a second accommodating groove is formed in the second surrounding wall portion; wherein, the material strength of the first surrounding wall portion is less than the material strength of the second surrounding wall portion, and the wall thickness of the first surrounding wall portion is greater than the wall thickness of the second surrounding wall portion.

[0034] In the above technical solution, since the material strength of the first surrounding wall portion is less than the material strength of the second surrounding wall portion, when the wall thickness of the first surrounding wall portion makes the structural strength of the first surrounding wall portion meet the requirements, the structural strength of the second surrounding wall portion can also be met by setting the wall thickness of the second surrounding wall portion to be smaller than the wall thickness of the first surrounding wall portion. Therefore, by thinning the second surrounding wall portion relative to the first surrounding wall portion, the material cost and weight of the second pole can be reduced while meeting the structural strength requirements, and the volume of the second accommodating groove can be increased.

[0035] In some embodiments, the first pole is an integral piece with the same main body material at all locations, and the second pole is an integral piece with the same main body material at all locations, and the material strength of the second pole is greater than the material strength of the first pole.

[0036] In the above technical solution, the processing difficulty and manufacturing cost of the first pole and the second pole can be reduced, and the material strength of the second pole at all locations is greater than the material strength of the first pole at all locations, thereby reducing the wall thickness of the second pole to a greater extent, which is further conducive to reducing the material cost and weight of the second pole.

[0037] In some embodiments, the first electrode is a positive electrode, and a main material of the first electrode is aluminum; the second electrode is a negative electrode, and a main material of the second electrode is copper.

[0038] In the above technical solution, since the material strength of aluminum is lower than that of copper, or in other words, the material strength of copper is higher than that of aluminum, the requirement that the material strength of the negative electrode column is greater than that of the positive electrode column can be met, which is beneficial to reducing the material cost and weight of the negative electrode column.

[0039] In some embodiments, a first pole cover is welded to the outside of the first pole, the first pole cover is an aluminum cover and is suitable for welding to the busbar component, a second pole cover is welded to the outside of the second pole, the second pole cover is a copper-aluminum composite cover and is welded to the second pole through the copper portion, and the aluminum portion of the second pole cover is suitable for welding to the busbar component.

[0040] In the above technical solution, it is beneficial to weld the pole cover plate, the pole and the current collecting component.

[0041] In some embodiments, the housing includes a first housing wall, and the first pole and the second pole are both disposed on the first housing wall.

[0042] In the above technical solution, by installing the first pole and the second pole on the shell wall on the same side, the processing can be simplified, the processing difficulty can be reduced, the processing efficiency can be improved, and the height space occupied in the shell can be reduced, thereby increasing the capacity of the battery cell.

[0043] In a second aspect, an embodiment of the present application further provides a battery comprising a battery cell according to any of the above solutions.

[0044] In the above technical solution, since the reliability and low cost of the battery cell according to the embodiment of the present application can be taken into account, it is beneficial to improve the performance of the battery and reduce the cost of the battery.

[0045] In a third aspect, an embodiment of the present application further provides an electrical device comprising a battery according to any of the above solutions.

[0046] In the above technical solution, since the performance of the battery is improved and the cost is reduced, it is beneficial to improve the working power performance of the electrical device and reduce the cost of the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0048] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0049] FIG2 is an exploded view of the structure of a battery provided in some embodiments of the present application;

[0050] FIG3 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0051] FIG4 is an exploded view of the structure of the battery cell shown in FIG3 ;

[0052] FIG5 is a schematic orthographic projection diagram of a battery cell provided in some embodiments of the present application;

[0053] FIG6 is a cross-sectional view along line AA in FIG5;

[0054] FIG7 is a partial enlarged view of the circled portion B in FIG6 ;

[0055] FIG8 is a partial enlarged view of the circled portion C in FIG6 ;

[0056] FIG9 is a cross-sectional view along line EE in FIG5 ;

[0057] FIG10 is a partial enlarged view of the circled portion D in FIG6 ;

[0058] FIG11 is a cross-sectional view taken along line FF in FIG5 .

[0059] Reference numerals: vehicle 1000; first direction X; second direction Y; third direction Z; battery 100; controller 200; motor 300; housing 101; first housing body 1011; second housing body 1012; battery cell 102; housing 1; accommodating chamber 10; first mounting hole 111; second mounting hole 112; first housing wall 11; second housing wall 12; third housing wall 13; pole 2; first pole 21; first through-hole 2111; first inner fixing portion 212; first outer fixing portion 213; first accommodating groove 2111; first end wall 2112; first surrounding wall 2113; first through-hole 2114; second pole 22; second through-hole 221; second inner fixing portion 222; second outer fixing portion 223; second accommodating groove 2211; second end wall 2212; second surrounding wall 2213; Second through hole 2214; sealed insulating assembly 3; first insulating part 31; second insulating part 32; sealing ring 33; battery cell assembly 4; active material coating portion 41; conductive portion 42; first conductive portion 421; first connecting section 4211; second conductive portion 422; second connecting section 4221; first pole cover 51; injection hole 511; second pole cover 52; copper portion 521; aluminum portion 522; sealing structure 6; first sealing member 61; second sealing member 62; pressure relief structure 7. DETAILED DESCRIPTION

[0060] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0061] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0062] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0063] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or communication between the inner sides of two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0064] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0065] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0066] The term "plurality" used in this application refers to two or more (including two).

[0067] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0068] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. A battery module generally includes multiple battery cells. A battery pack generally includes a casing for enclosing one or more battery cells or one or more battery modules. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0069] A battery cell consists of a housing, a cell assembly, and an electrolyte. The housing holds the cell assembly and electrolyte. The cell assembly includes at least one electrode assembly, which consists of a positive electrode sheet, a negative electrode sheet, and a separator. The electrode assembly can be a wound or stacked structure. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets.

[0070] A positive electrode sheet generally includes a positive current collector and a positive active material layer. The positive active material layer is directly or indirectly coated on the positive current collector. The uncoated positive current collector protrudes from the coated positive current collector, serving as the positive tab. For lithium-ion batteries, for example, the positive current collector can be made of aluminum, and the positive active material layer can be made of lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide.

[0071] A negative electrode sheet generally includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is directly or indirectly coated on the negative electrode current collector. The negative electrode current collector not coated with the negative electrode active material layer protrudes from the negative electrode current collector coated with the negative electrode active material layer, and the negative electrode current collector not coated with the negative electrode active material layer serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material layer can be made of carbon, silicon, or other materials.

[0072] To ensure that high currents can pass without melting, the positive electrode tabs are multiple and stacked together to form the positive electrode tab portion, and the negative electrode tabs are multiple and stacked together to form the negative electrode tab portion. The housing is provided with a pole post, and the positive electrode tab portion is electrically connected to the positive electrode post, and the negative electrode tab portion is electrically connected to the negative electrode post. For example, the tab portion can be connected to the pole post to form a direct electrical connection between the tab portion and the pole post. For another example, the battery cell assembly can include an adapter plate, the tab portion is connected to the adapter plate, and the adapter plate is connected to the pole post to form an indirect electrical connection between the tab portion and the pole post.

[0073] The material of the isolation film is not limited, and can be, for example, polypropylene or polyethylene.

[0074] In the battery cells of the related art, the poles are installed in the shell. If the pressure resistance level of the poles is insufficient, when the pressure inside the shell is high, the poles are easily squeezed out. Moreover, when the area of ​​the poles is large, the pressure resistance level of the poles is even lower, and they are more likely to be squeezed out by the gas inside the shell. To this end, in the embodiments of the present application, different wall thicknesses are designed for poles with different material strengths, so that the wall thickness of the inner fixing part of the pole with relatively weak material strength is relatively thick, thereby improving its pressure resistance level and reducing the risk of it escaping from the shell, while the wall thickness of the inner fixing part of the pole with relatively strong material strength is relatively thin, thereby reducing the material cost and weight while meeting its pressure resistance level, and saving its space occupation in the shell, thereby improving the reliability of the battery cells and reducing the production cost of the battery cells.

[0075] Material strength is a physical property of the material itself, referring to its yield strength. This can be determined through table lookup or testing. For example, there are at least two methods for determining this. For example, method one involves analyzing the material's trace elements using inductively coupled plasma reflectance spectroscopy, and then determining the material's strength by table lookup. For example, for aluminum, one can refer to GB / T 3880, "Aluminum and Aluminum Alloy Plate, Strip, and Foil," and for copper, one can refer to GB / T 5231, "Processing Copper and Copper Alloy Grades and Chemical Composition." For example, method two involves testing the material's yield strength using GB228-87, "Metal Tensile Test Methods."

[0076] The present invention provides an electrical device using a battery as a power source. The electrical device may include, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, and the like. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft.

[0077] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0078] Please refer to Figure 1, which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided on the inside of the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an 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 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0079] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0080] Please refer to Figure 2, which is an exploded view of the structure of the battery 100 provided in some embodiments of the present application. The battery 100 includes a box body 101 and a plurality of battery cells 102, and the battery cells 102 are accommodated in the box body 101. The box body 101 is used to provide an assembly space for the battery cells 102, and the box body 101 can adopt a variety of structures. In some embodiments, the box body 101 may include a first box body 1011 and a second box body 1012, and the first box body 1011 and the second box body 1012 cover each other, and the first box body 1011 and the second box body 1012 jointly define an assembly space for accommodating the battery cells 102. The second box body 1012 can be a hollow structure with one end open, and the first box body 1011 can be a plate-like structure. The first box body 1011 covers the open side of the second box body 1012, so that the first box body 1011 and the second box body 1012 jointly define an assembly space. The first box body 1011 and the second box body 1012 can also be hollow structures with one side open, and the open side of the first box body 1011 covers the open side of the second box body 1012. Of course, the box body 101 formed by the first box body 1011 and the second box body 1012 can be of various shapes, such as a cylinder, a cuboid, etc.

[0081] In the battery 100, multiple battery cells 102 can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to multiple battery cells 102 being connected both in series and in parallel. Multiple battery cells 102 can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure formed by the multiple battery cells 102 is housed within the housing 101. Alternatively, the battery 100 can be constructed by first connecting multiple battery cells 102 in series, in parallel, or in a hybrid configuration to form a battery module. The multiple battery modules are then connected in series, in parallel, or in a hybrid configuration to form a single structure, which is then housed within the housing 101. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 102.

[0082] Each battery cell 102 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 102 can be cylindrical, flat, or rectangular. For example, FIG3 is a schematic diagram of the structure of a battery cell provided in some embodiments of the present application. Referring to the embodiment shown in FIG3 , the length direction of the battery cell 102 is a first direction X, the width direction of the battery cell 102 is a second direction Y, and the height direction of the battery cell 102 is a third direction Z. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0083] FIG4 is an exploded view of the structure of the battery cell 102 shown in FIG3 , FIG5 is an orthographic schematic diagram of the battery cell 102 provided in some embodiments of the present application, FIG6 is a cross-sectional view along line AA in FIG5 , and FIG7 is a partial enlarged view of the circled portion B in FIG6 . In some embodiments of the present application, in conjunction with FIG3 to FIG7 , the battery cell 102 includes: a shell 1 and a pole 2, the pole 2 is provided in the shell 1, and a receiving cavity 10 is formed on the inner side of the shell 1. Exemplarily, the battery cell 102 includes a cell assembly 4, and the cell assembly 4 may include an active material coating portion 41 and a conductive portion 42 connected to the active material coating portion 41, the active material coating portion 41 is received in the receiving cavity 10, and the conductive portion 42 is welded to the pole 2 so that the conductive portion 42 is electrically connected between the active material coating portion 41 and the pole 2. It is understandable that the active material coating portion 41 may include a current collector coated with an active material layer, and the conductive portion 42 may include only the pole ear portion, or may include the pole ear portion and a transition piece electrically connected to the pole ear portion, etc., which is not limited here.

[0084] 3-6 , the pole 2 provided on the housing 1 includes a first pole 21 and a second pole 22. For example, the housing 1 may include multiple housing walls, and the first pole 21 and the second pole 22 may be provided on the same housing wall or on different housing walls. For example, the housing 1 may include a first housing wall 11, a second housing wall 12, and a third housing wall 13, wherein the first housing wall 11 and the second housing wall 12 are opposite to each other, the third housing wall 13 is connected between the first housing wall 11 and the second housing wall 12, and the cross-sectional shape of the third housing wall 13 is consistent with the contour shape of any one of the first housing wall 11 and the second housing wall 12, wherein the first pole 21 and the second pole 22 are both arranged on the first housing wall 11; or, the first pole 21 and the second pole 22 are both arranged on the same side surface of the third housing wall 13; or, the first pole 21 is arranged on the first housing wall 11, and the second pole 22 is arranged on the second housing wall 12 or the third housing wall 13; or, the first pole 21 and the second pole 22 are respectively arranged on different side surfaces of the third housing wall 13, and so on. To simplify the description, the following mainly uses an example in which both the first pole 21 and the second pole 22 are provided on the first shell wall 11. After reading the technical solutions described below, those skilled in the art will obviously understand other technical solutions in which the first pole 21 and the second pole 22 are not provided on the first shell wall 11 at the same time.

[0085] 7 and 8 , the first pole 21 includes a first penetration portion 211 passing through the housing 1 , and a first inner fixing portion 212 and a first outer fixing portion 213 connected to the first penetration portion 211 and respectively disposed on the inner and outer sides of the housing 1 .

[0086] Exemplarily, the first pole 21 includes a first penetration portion 211, a first inner fixing portion 212, and a first outer fixing portion 213. The first housing wall 11 has a first mounting hole 111, and the first penetration portion 211 penetrates the first mounting hole 111, that is, at least a portion of the first penetration portion 211 is located within the first mounting hole 111, and the orthographic projection of the first penetration portion 211 on the projection plane falls within the orthographic projection range of the first mounting hole 111 on the projection plane, with the axial direction of the first mounting hole 111 as the projection direction and the plane perpendicular to the axial direction of the first mounting hole 111 as the projection plane. This allows the first penetration portion 211 to penetrate the first mounting hole 111.

[0087] The orthographic projection of the first inner fixing portion 212 on the projection plane and the orthographic projection of the first housing wall 11 on the projection plane have an intersection area, so that the portion of the first inner fixing portion 212 corresponding to the intersection area directly faces the first housing wall 11, thereby preventing the first pole 21 from moving relative to the first housing wall 11 toward the first outer fixing portion 213 (i.e., moving outward from the first housing wall 11). The orthographic projection of the first outer fixing portion 213 on the projection plane and the orthographic projection of the first housing wall 11 on the projection plane have an intersection area, so that the portion of the first outer fixing portion 213 corresponding to the intersection area directly faces the first housing wall 11, thereby preventing the first pole 21 from moving relative to the first housing wall 11 toward the first inner fixing portion 212 (i.e., moving inward from the first housing wall 11).

[0088] 7 and 8 , the second pole 22 includes a second penetration portion 221 penetrated through the housing 1 , and a second inner fixing portion 222 and a second outer fixing portion 223 connected to the second penetration portion 221 and respectively disposed on the inner and outer sides of the housing 1 .

[0089] Exemplarily, the second pole 22 includes a second penetration portion 221, a second inner fixing portion 222, and a second outer fixing portion 223. The first shell wall 11 has a second mounting hole 112, and the second penetration portion 221 is penetrated by the second mounting hole 112, that is, at least a portion of the second penetration portion 221 is located within the second mounting hole 112, and the orthographic projection of the second penetration portion 221 on the projection plane falls within the orthographic projection range of the second mounting hole 112 on the projection plane, with the axial direction of the second mounting hole 112 as the projection direction and the plane perpendicular to the axial direction of the second mounting hole 112 as the projection plane. This allows the second penetration portion 221 to penetrate the second mounting hole 112.

[0090] The orthographic projection of the second inner fixing portion 222 on the projection plane and the orthographic projection of the first housing wall 11 on the projection plane have an intersection area, so that the portion of the second inner fixing portion 222 corresponding to the intersection area directly faces the first housing wall 11, thereby at least partially facing the first housing wall 11, thereby preventing the second pole 22 from moving relative to the first housing wall 11 in the direction of the second outer fixing portion 223 (i.e., moving outward from the first housing wall 11). The orthographic projection of the second outer fixing portion 223 on the projection plane and the orthographic projection of the first housing wall 11 on the projection plane have an intersection area, so that the portion of the second outer fixing portion 223 corresponding to the intersection area directly faces the first housing wall 11, thereby at least partially facing the first housing wall 11, thereby preventing the second pole 22 from moving relative to the first housing wall 11 in the direction of the second inner fixing portion 222 (i.e., moving inward from the first housing wall 11).

[0091] 7 and 8 , the material strength of the first inner fixing portion 212 is less than that of the second inner fixing portion 222, and the wall thickness t1 of the first inner fixing portion 212 is greater than the wall thickness t2 of the second inner fixing portion 222. In other words, of the first inner fixing portion 212 and the second inner fixing portion 222, the material strength of the first inner fixing portion 212 is relatively weaker, while the material strength of the second inner fixing portion 222 is relatively stronger. Furthermore, of the first inner fixing portion 212 and the second inner fixing portion 222, the wall thickness t1 of the first inner fixing portion 212 is relatively greater, while the wall thickness t2 of the second inner fixing portion 222 is relatively smaller. Thus, compared to the second inner fixing portion 222, the first inner fixing portion 212 has a relatively weaker material strength and a relatively greater wall thickness t1, while the second inner fixing portion 222 has a relatively greater material strength and a relatively smaller wall thickness t2.

[0092] Thus, when the pressure within the housing 1 is high, the first inner fixing portion 212, which has a relatively low material strength and a relatively large wall thickness t1, can reliably abut the housing 1, thereby preventing the first pole 21 from being dislodged from the first mounting hole 111. This satisfies the pressure resistance requirements of the first pole 21 and ensures a reliable connection between the first pole 21 and the housing 1. Furthermore, because the material strength of the second inner fixing portion 222 is greater than that of the first inner fixing portion 212, even when the wall thickness t2 of the second inner fixing portion 222 is smaller than the wall thickness t1 of the first inner fixing portion 212, the second inner fixing portion 222 can reliably abut the housing 1, thereby satisfying the pressure resistance requirements of the second pole 22 and ensuring a reliable connection between the second pole 22 and the housing 1. Furthermore, because the wall thickness t2 of the second inner fixing portion 222 is thinner than the wall thickness t1 of the first inner fixing portion 212, the material cost of the second inner fixing portion 222 can be reduced.

[0093] As described above, according to the battery cell 102 of the embodiment of the present application, while meeting the respective pressure resistance requirements of the first terminal 21 and the second terminal 22, the wall thickness of the second inner fixing portion 222 is thinner than that of the first inner fixing portion 212, thereby reducing the material cost and weight of the second inner fixing portion 222. Furthermore, since the wall thickness of the second inner fixing portion 222 is thinner than that of the first inner fixing portion 212, space inside the second inner fixing portion 222 is freed up, i.e., the space occupied by the second inner fixing portion 222 within the housing 1 is reduced. This freed-up space can be used to increase the amount of electrolyte injected or to improve the ability to accommodate gas generated during operation of the battery cell 102, thereby improving the performance of the battery cell 102.

[0094] For the battery cell 102, the pressure inside the shell 1 is relatively high, which can easily squeeze the terminal 2 out. Especially when the area of ​​the terminal 2 is large, the terminal 2 has a low pressure resistance level, making it more likely to be squeezed out by the air pressure inside the shell 1. In the embodiment of the present application, by setting the wall thickness of the inner fixing part with weaker material strength to be thicker, the shell improves its pressure resistance level, while the wall thickness of the inner fixing part with stronger material strength is thinner, which can reduce material costs.

[0095] For a battery cell, if the thickness of the inner fixing portion of the terminal 2 located on the inner side of the shell 1 is relatively thick, then in the axial direction of the terminal 2, it will occupy more height space in the accommodating cavity 10, causing the height of the battery cell assembly 4 in the shell 1 to be reduced, affecting the capacity of the battery cell 102. If the first inner fixing portion 212, which has a relatively weak material strength, can meet the pressure resistance level, then the second inner fixing portion 222, which has a relatively strong material strength, can also meet the pressure resistance level when the wall thickness is equal to or less than the wall thickness of the first inner fixing portion 212. Therefore, the capacity of the battery cell 102 can be determined by the wall thickness of the first inner fixing portion 212, which has a relatively weak material strength. In the embodiment of the present application, by setting the wall thickness of the second inner fixing portion 222 to be thinner than the wall thickness of the first inner fixing portion 212, the material cost and weight of the second terminal 22 can be reduced by thinning the second inner fixing portion 222 without affecting the capacity of the battery cell 102 and the pressure resistance level of the second terminal 22.

[0096] In some embodiments of the present application, as shown in FIG6 and FIG8 , the first penetration portion 211 defines a first receiving groove 2111, which is open toward the inside or outside of the housing 1. The first penetration portion 211 includes a first end wall portion 2112 disposed opposite the opening of the first receiving groove 2111. It is understood that if the first receiving groove 2111 is open toward the inside of the housing 1, the first end wall portion 2112 is located on the side of the first receiving groove 2111 away from the receiving cavity 10. For example, when the first receiving groove 2111 is open toward the bottom, the first end wall portion 2112 constitutes the top wall of the first receiving groove 2111. If the first receiving groove 2111 is open toward the outside of the housing 1, the first end wall portion 2112 is located on the side of the first receiving groove 2111 closer to the receiving cavity 10. For example, when the first receiving groove 2111 is open toward the top, the first end wall portion 2112 constitutes the bottom wall of the first receiving groove 2111. In addition, the first penetration portion 211 can also define two first accommodating grooves 2111 arranged back to back, and one of the two first accommodating grooves 2111 that is relatively close to the accommodating cavity 10 is open toward the inner side of the shell 1, and one of the two first accommodating grooves 2111 that is relatively far away from the accommodating cavity 10 is open toward the outer side of the shell 1.

[0097] Thus, since the first receiving groove 2111 is provided on the first penetration portion 211 of the first pole 21, the first pole 21 is hollow. This can reduce the material usage of the first pole 21 while increasing the surface area of ​​the first pole 21, thereby reducing the material cost and weight of the first pole 21. Furthermore, it will be understood that the pole 2 is electrically connected between the conductive portion 42 and the current collecting component. When the surface area of ​​the first pole 21 is increased, the electrical connection area between the first pole 21 and the first conductive portion 421 is increased, thereby facilitating improved current flow efficiency.

[0098] For example, referring to FIG8 , the first inner fixing portion 212 and the first end wall portion 2112 are made of the same primary material, and the wall thickness t3 of the first end wall portion 2112 is greater than the wall thickness t1 of the first inner fixing portion 212. Thus, since the material strength of the first inner fixing portion 212 is relatively weak, the material strength of the first end wall portion 2112 is also relatively weak. Since the first end wall portion 2112 is opposite the first receiving groove 2111, by setting the wall thickness t3 of the first end wall portion 2112 to be greater than the wall thickness t1 of the first inner fixing portion 212, the structural strength and pressure resistance of the first end wall portion 2112 can be improved. For example, the primary material of the first inner fixing portion 212 and the first end wall portion 2112 is aluminum. The term "primary material" as used herein can be understood as follows: when composed of only one material, that material is the primary material; when composed of an alloy or multiple materials, the component with the highest content is the primary material.

[0099] For example, when the axial direction of the first mounting hole 111 is taken as the projection direction and the surface perpendicular to the axial direction of the first mounting hole 111 is taken as the projection surface, and the orthographic projection area of ​​the first internal fixing portion 212 on the projection surface is smaller than the orthographic projection area of ​​the first end wall portion 2112 on the projection surface, by setting the wall thickness of the first end wall portion 2112 to be greater than the wall thickness of the first internal fixing portion 212, the structural strength of the first end wall portion 2112 with a relatively larger area can be improved.

[0100] In short, by setting the wall thickness of the first end wall portion 2112 of the first electrode 21 (generally, the center of the first electrode 21) to be greater than the wall thickness of the first inner fixing portion 212 (generally, the edge of the first electrode 21), this is equivalent to increasing the wall thickness at the center of the first electrode 21 while meeting the pressure resistance level at the edge of the first electrode 21. This allows the center of the first electrode 21, despite its larger area, to exhibit better structural strength, thereby improving the reliability of the first electrode 21. In other words, by setting the wall thickness of the first inner fixing portion 212 (i.e., the edge of the first electrode 21) to be less than the wall thickness of the first end wall portion 2112 of the first electrode 21 (i.e., the center of the first electrode 21), this is equivalent to reducing the wall thickness at the edge of the first electrode 21 while meeting the structural strength of the center of the first electrode 21. This saves material, reduces cost and weight, and reduces the height space occupied by the edge of the first electrode 21 within the housing 1, thereby increasing the capacity of the battery cell 102.

[0101] For example, as shown in Figures 8 and 9 , a first through-hole 2114 is formed on the first end wall portion 2112, connecting the inner side of the housing 1 (i.e., the accommodating chamber 10) with the first accommodating groove 2111. The battery cell assembly 4 of the battery cell 102 includes a first conductive portion 421 electrically connected to the first terminal 21. The first conductive portion 421 is disposed in the first through-hole 2114 and includes a first connecting segment 4211 received in the first accommodating groove 2111. The first connecting segment 4211 overlaps the first end wall portion 2112 and is welded to the first end wall portion 2112. The welding method is not limited and can be, for example, laser welding.

[0102] Thus, by providing the first through-hole 2114, the first conductive portion 421 extends into the first receiving groove 2111. The first receiving groove 2111 can accommodate the first conductive portion 421, reducing the height space occupied by the first conductive portion 421 in the receiving chamber 10 and increasing the capacity of the battery cell 102. Furthermore, when the first receiving groove 2111 is open toward the outside of the housing 1, welding the first connecting section 4211 to the first end wall 2112 from the outside of the housing 1 is facilitated, reducing processing difficulty.

[0103] In the above technical solution, since the wall thickness of the first end wall portion 2112 of the first pole 21 is greater than the wall thickness of the first internal fixing portion 212, the welding penetration depth of the first connecting section 4211 and the first end wall portion 2112 meets the requirements under the premise that the pressure resistance level of the first pole 21 at the edge is sufficient, which is beneficial to improve the welding connection strength between the first end wall portion 2112 and the first connecting section 4211, thereby improving the reliability and stability of the electrical connection between the first pole 21 and the first conductive portion 421.

[0104] If the inner fixing portion of the pole 2 located inside the shell 1 is thicker, it will occupy more height space of the accommodating cavity 10 in the axial direction of the pole 2, requiring the height of the battery cell assembly 4 in the shell 1 to be reduced, affecting the capacity of the battery cell 102. For the first pole 21 with weaker material strength, by setting unequal thickness at the edge and center of the first pole 21, the wall thickness of the first inner fixing portion 212 is set to be smaller than the wall thickness of the first end wall 2112, thereby strengthening the relatively thick first end wall 2112 to meet the welding penetration and structural strength requirements. At the same time, the relatively thin first inner fixing portion 212 is thinned relative to the first end wall 2112. Under the premise of meeting the pressure resistance level, the height space occupied by the accommodating cavity 10 is reduced, the capacity of the battery cell 102 is increased, and the material cost and weight are reduced.

[0105] In some embodiments, as shown in Figures 8 and 9, the first end wall portion 2112 is disposed relative to the first receiving groove 2111, near the inner side of the housing 1 (i.e., the receiving chamber 10), and the inner end surface of the first inner fixing portion 212 (i.e., the side surface near the receiving chamber 10) is flush with the inner end surface of the first end wall portion 2112 (i.e., the side surface near the receiving chamber 10). For example, the first pole 21 is disposed at the top of the housing 1, the first receiving groove 2111 is open upward, the first end wall portion 2112 constitutes the bottom wall of the first receiving groove 2111, and the lower surface of the first inner fixing portion 212 is flush with the lower surface of the first end wall portion 2112.

[0106] In the above technical solution, by setting the side surface of the first inner fixing portion 212 close to the accommodating cavity 10 to be flush with the side surface of the first end wall portion 2112 close to the accommodating cavity 10, the processing of the first pole 21 can be simplified, the processing difficulty can be reduced, and the production cost can be reduced. Moreover, since the inner end surface of the first end wall portion 2112 does not protrude from the inner end surface of the first inner fixing portion 212 in the direction of the accommodating cavity 10, the height space occupied by the center of the first pole 21 in the shell 1 is reduced, thereby reducing the risk of short circuit between the first pole 21 and the battery cell assembly 4.

[0107] In some embodiments, in combination with Figure 8, under the premise that the wall thickness t3 of the first end wall portion 2112 is greater than the wall thickness t1 of the first inner fixing portion 212, the first end wall portion 2112 and the first inner fixing portion 212 are both made of aluminum, and the wall thickness t3 of the first end wall portion 2112 can range from 2.2 mm to 0.8 mm, for example, 2.2 mm, 2.0 mm, 1.8 mm, 1.6 mm, 1.4 mm, 1.2 mm, 1.0 mm, 0.8 mm, etc., and the wall thickness t1 of the first inner fixing portion 212 can range from 2 mm to 0.8 mm, for example, 2.0 mm, 1.8 mm, 1.6 mm, 1.4 mm, 1.2 mm, 1.0 mm, 0.8 mm, etc.

[0108] Therefore, the wall thickness t3 of the first end wall portion 2112 is not too large, so that the volume of the first accommodating groove 2111 is not too small, which meets the storage requirements of the first conductive part 421. The wall thickness t3 of the first end wall portion 2112 is not too small, so that the first end wall portion 2112 can meet the welding penetration requirements with the first conductive part 421 and the structural strength requirements of the first end wall portion 2112. The wall thickness t1 of the first internal fixing portion 212 is not too large, thereby reducing the height space occupied by the first internal fixing portion 212 in the accommodating cavity 10, increasing the capacity of the battery cell 102, and reducing material cost and weight. The wall thickness t1 of the first internal fixing portion 212 is not too small, thereby meeting the pressure resistance level of the first pole 21 and improving the problem that the first pole 21 falls out of the shell 1 due to the high pressure in the shell 1.

[0109] Specifically, the wall thicknesses of the first end wall 2112 and the first inner fixing portion 212 can be specifically set and selected based on the system capacity of the battery cell 102. For example, the wall thickness of the first end wall 2112 is 2.2 mm, and the wall thickness of the first inner fixing portion 212 is 2 mm. This effectively meets the requirements for accommodating the first conductive portion 421, and the first end wall 2112 can meet the welding penetration requirements with the first conductive portion 421, as well as the structural strength requirements of the first end wall 2112. Furthermore, the first inner fixing portion 212 occupies a small amount of height space in the accommodating cavity 10, thereby increasing the capacity of the battery cell 102 and reducing material cost and weight. Furthermore, the pressure resistance level of the first terminal 21 can be met, thereby improving the problem of the first terminal 21 detaching from the housing 1 due to high pressure within the housing 1.

[0110] In some embodiments of the present application, as shown in FIG6 and FIG10 , the second penetration portion 221 defines a second receiving groove 2211, which is open toward the inside or outside of the housing 1. The second penetration portion 221 includes a second end wall portion 2212 disposed opposite the opening of the second receiving groove 2211. It is understood that if the second receiving groove 2211 is open toward the inside of the housing 1, the second end wall portion 2212 is located on the side of the second receiving groove 2211 away from the receiving cavity 10. For example, when the second receiving groove 2211 is open toward the bottom, the second end wall portion 2212 constitutes the top wall of the second receiving groove 2211. If the second receiving groove 2211 is open toward the outside of the housing 1, the second end wall portion 2212 is located on the side of the second receiving groove 2211 closer to the receiving cavity 10. For example, when the second receiving groove 2211 is open toward the top, the second end wall portion 2212 constitutes the bottom wall of the second receiving groove 2211. In addition, the second penetration portion 221 can also define two second accommodating grooves 2211 arranged back to back, and the one of the two second accommodating grooves 2211 that is relatively close to the accommodating cavity 10 is open toward the inner side of the shell 1, and the one of the two second accommodating grooves 2211 that is relatively far away from the accommodating cavity 10 is open toward the outer side of the shell 1.

[0111] Thus, since the second receiving groove 2211 is provided on the second penetration portion 221 of the second pole 22, the second pole 22 is hollow. This can reduce the material usage of the second pole 22 while increasing the surface area of ​​the second pole 22, thereby reducing the material cost and weight of the second pole 22. Moreover, it can be understood that the pole 2 is electrically connected between the conductive portion 42 and the current collecting component. When the surface area of ​​the second pole 22 is increased, the electrical connection area between the second pole 22 and the second conductive portion 422 is increased, thereby facilitating improved current flow efficiency.

[0112] By way of example, with reference to FIG10 , the second inner fixing portion 222 and the second end wall portion 2212 are primarily made of the same material, and the wall thickness t4 of the second end wall portion 2212 is less than the wall thickness t2 of the second inner fixing portion 222. Thus, because the material strength of the second inner fixing portion 222 is relatively strong, the material strength of the second end wall portion 2212 is also relatively strong. By setting the wall thickness t4 of the second end wall portion 2212 smaller than the wall thickness t2 of the second inner fixing portion 222, the wall thickness of the second inner fixing portion 222 is relatively large to meet the pressure resistance level of the second pole 22, while the wall thickness of the second end wall portion 2212 is relatively small, thereby increasing the volume of the second receiving groove 2211 and reducing the material cost and weight of the second pole 22. For example, the primary materials of the second inner fixing portion 222 and the second end wall portion 2212 are both copper.

[0113] In short, by setting the wall thickness of the second end wall portion 2212 of the second pole 22 (generally, the center of the second pole 22) to be smaller than the wall thickness of the second inner fixing portion 222 (generally, the edge of the second pole 22), this is equivalent to reducing the wall thickness of the center of the second pole 22, where the material strength is relatively greater, while ensuring the withstand voltage level at the edge of the second pole 22. This reduces the material cost and weight of the second pole 22 while ensuring the structural strength at the center of the second pole 22. Furthermore, the volume of the second receiving groove 2211 is increased. In other words, by setting the wall thickness of the second inner fixing portion 222 (i.e., the edge of the second pole 22) to be larger than the wall thickness of the second end wall portion 2212 of the second pole 22 (i.e., the center of the second pole 22), this is equivalent to increasing the wall thickness at the edge of the second pole 22 while ensuring the structural strength at the center of the second pole 22, thereby improving the withstand voltage level of the second pole 22.

[0114] When the first pole 21 and the second pole 22 are arranged on the same side wall of the shell 1, even if the wall thickness of the second inner fixing part 222 is increased, since the wall thickness of the second inner fixing part 222 is less than the wall thickness of the first inner fixing part 212, the height space occupied in the shell 1 will not be increased, thereby ensuring the capacity of the battery cell 102.

[0115] For example, as shown in Figures 10 and 11, a second through-hole 2214 is formed on the second end wall portion 2212, connecting the inner side of the housing 1 (i.e., the accommodating chamber 10) with the second accommodating groove 2211. The battery cell assembly 4 of the battery cell 102 includes a second conductive portion 422 connected to the second pole 22. The second conductive portion 422 is disposed in the second through-hole 2214 and includes a second connecting segment 4221 received in the second accommodating groove 2211. The second connecting segment 4221 overlaps the second end wall portion 2212 and is welded to the second end wall portion 2212. The welding method is not limited and can be, for example, laser welding.

[0116] Thus, by providing the second through-hole 2214, the second conductive portion 422 extends into the second receiving groove 2211. The second receiving groove 2211 can accommodate the second conductive portion 422, reducing the height space occupied by the second conductive portion 422 in the receiving cavity 10 and increasing the capacity of the battery cell 102. Furthermore, when the second receiving groove 2211 is open toward the outside of the housing 1, welding the second connecting section 4221 to the second end wall 2212 from the outside of the housing 1 is facilitated, reducing processing difficulty.

[0117] In the above technical solution, since the wall thickness of the second end wall portion 2212 of the second pole 22 is less than the wall thickness of the second inner fixing portion 222, the volume of the second accommodating groove 2211 at the center of the second pole 22 can be increased under the premise that the pressure resistance level of the second pole 22 at the edge is sufficient, so as to facilitate the accommodation of the second conductive portion 422 to a greater extent and facilitate the welding of the second connecting section 4221 and the second end wall portion 2212.

[0118] If the inner fixing portion of the terminal 2 located inside the housing 1 is thicker, it will occupy a larger height space of the accommodating cavity 10 in the axial direction of the terminal 2, requiring the height of the battery cell assembly 4 within the housing 1 to be reduced, affecting the capacity of the battery cell 102. For the second terminal 22, which has a relatively strong material strength, the capacity of the battery cell 102 can be determined by the first terminal 21, which has a relatively weak material strength. Therefore, by setting the thickness of the second inner fixing portion 222 to be unequal at the edge and center of the second terminal 22, the wall thickness of the second inner fixing portion 222 is set to be greater than the wall thickness of the second end wall 2212 and less than the wall thickness of the first inner fixing portion 212. While ensuring the capacity of the battery cell 102, the pressure resistance of the second terminal 22 can be improved by thickening the second inner fixing portion 222 relative to the second end wall 2212. Furthermore, by thinning the second end wall 2212 relative to the second inner fixing portion 222, the volume of the second accommodating groove 2211 can be increased while maintaining the structural strength of the second end wall 2212, thereby reducing material costs.

[0119] If the second end wall portion 2212 and the second inner fixing portion 222 are of equal thickness and are both relatively thin, during simulated inflation, the second inner fixing portion 222 is equivalent to a cantilever beam, with a large bending moment and obvious deformation. By setting the wall thickness of the second inner fixing portion 222 to be greater than the wall thickness of the second end wall portion 2212, the thickened second fixing portion can be used to improve the pressure resistance level of the second pole 22.

[0120] In some embodiments, as shown in Figures 10 and 11, the second end wall portion 2212 is disposed relative to the second receiving groove 2211, near the inner side of the housing 1 (i.e., the receiving chamber 10), and the inner end surface of the second inner fixing portion 222 (i.e., the side surface near the receiving chamber 10) is flush with the inner end surface of the second end wall portion 2212 (i.e., the side surface near the receiving chamber 10). For example, the second pole 22 is disposed at the top of the housing 1, the second receiving groove 2211 is open upward, the second end wall portion 2212 constitutes the bottom wall of the second receiving groove 2211, and the lower surface of the second inner fixing portion 222 is flush with the lower surface of the second end wall portion 2212.

[0121] In the above technical solution, by setting the side surface of the second inner fixing portion 222 close to the accommodating cavity 10 to be flush with the side surface of the second end wall portion 2212 close to the accommodating cavity 10, the processing of the second pole 22 can be simplified, the processing difficulty can be reduced, and the production cost can be reduced. Moreover, since the inner end surface of the second end wall portion 2212 does not protrude from the inner end surface of the second inner fixing portion 222 in the direction of the accommodating cavity 10, the height space occupied by the center of the second pole 22 in the shell 1 is reduced, thereby reducing the risk of short circuit between the second pole 22 and the battery cell assembly 4.

[0122] In some embodiments, in combination with Figure 10, under the premise that the wall thickness t4 of the second end wall portion 2212 is less than the wall thickness t2 of the second inner fixing portion 222, the second end wall portion 2212 and the second inner fixing portion 222 are both made of copper, and the wall thickness t4 of the second end wall portion 2212 can range from 1.3mm to 0.8mm, for example, 1.3mm, 1.2mm, 1.1mm, 1.0mm, 0.9mm, 0.8mm, etc., and the wall thickness t2 of the second inner fixing portion 222 can range from 1.6mm to 0.8mm, for example, 1.6mm, 1.5mm, 1.4mm, 1.3mm, 1.2mm, 1.1mm, 1.0mm, 0.9mm, 0.8mm, etc.

[0123] Therefore, the wall thickness t4 of the second end wall portion 2212 is not too large, thereby making the volume of the second accommodating groove 2211 larger, increasing the storage demand for the second conductive part 422, and the material cost is low. The wall thickness t4 of the second end wall portion 2212 is not too small, thereby making the second end wall portion 2212 able to meet the welding penetration requirement with the second conductive part 422 and the structural strength requirement of the second end wall portion 2212. The wall thickness t2 of the second inner fixed portion 222 is not too large, thereby reducing the height space occupied by the second inner fixed portion 222 in the accommodating cavity 10, increasing the capacity of the battery cell 102, and reducing the material cost and weight. The wall thickness t2 of the second inner fixed portion 222 is not too small, thereby meeting the pressure resistance level of the second pole 22, and improving the problem that the second pole 22 falls out of the shell 1 due to the high pressure in the shell 1.

[0124] Specifically, the wall thicknesses of the second end wall 2212 and the second inner fixing portion 222 can be specifically set and selected based on the system capacity of the battery cell 102. For example, the wall thickness t4 of the second end wall 2212 is 1.2 mm, and the wall thickness t2 of the second inner fixing portion 222 is 1.5 mm. This effectively meets the need to accommodate the second conductive portion 422, and the second end wall 2212 can meet the welding penetration requirements with the second conductive portion 422, as well as the structural strength requirements of the second end wall 2212. This reduces the material cost and weight of the second end wall 2212, and minimizes the height space occupied by the second inner fixing portion 222 in the accommodating cavity 10, thereby increasing the capacity of the battery cell 102 and reducing material costs. Furthermore, the pressure resistance level of the second terminal 22 can be met, thereby alleviating the problem of the second terminal 22 being dislodged from the housing 1 due to high pressure within the housing 1.

[0125] In some embodiments, as shown in Figures 7, 8 and 10, the first penetration portion 211 defines a first accommodating groove 2111, the first accommodating groove 2111 is open toward the inner side or the outer side of the shell 1, and the first penetration portion 211 includes a first end wall portion 2112 arranged opposite to the opening of the first accommodating groove 2111, and the second penetration portion 221 defines a second accommodating groove 2211, the second accommodating groove 2211 is open toward the inner side or the outer side of the shell 1, and the second penetration portion 221 includes a second end wall portion 2212 arranged opposite to the opening of the second accommodating groove 2211, wherein the relative position relationship between the first accommodating groove 2111 and the first end wall portion 2112 can refer to the above introduction, and the relative position relationship between the second accommodating groove 2211 and the second end wall portion 2212 can refer to the above introduction, and will not be repeated here.

[0126] In this embodiment, the material strength of the first end wall portion 2112 is less than that of the second end wall portion 2212, and the wall thickness t3 of the first end wall portion 2112 is greater than the wall thickness t4 of the second end wall portion 2212. Thus, because the material strength of the first end wall portion 2112 is less than that of the second end wall portion 2212, if the first end wall portion 2112 is less susceptible to deformation during the simulated inflation process, the wall thickness of the second end wall portion 2212 can be smaller than that of the first end wall portion 2112 to also be less susceptible to deformation. Therefore, setting the wall thickness of the second end wall portion 2212 smaller than that of the first end wall portion 2112 can effectively increase the volume of the second receiving groove 2211 and reduce the material cost and weight of the second pole 22.

[0127] In some embodiments, as shown in Figures 6 and 7, the material strength of the first external fixing portion 213 is less than the material strength of the second external fixing portion 223, and the wall thickness t5 of the first external fixing portion 213 is greater than the wall thickness t6 of the second external fixing portion 223. Thus, because the material strength of the first external fixing portion 213 is less than the material strength of the second external fixing portion 223, when the wall thickness of the first external fixing portion 213 satisfies the structural strength requirements of the first external fixing portion 213, the structural strength requirements of the second external fixing portion 223 can also be met by setting the wall thickness of the second external fixing portion 223 to be thinner than the wall thickness of the first external fixing portion 213. Therefore, by reducing the thickness of the second external fixing portion 223 relative to the first external fixing portion 213, the material cost and weight of the second pole 22 can be reduced while meeting the structural strength requirements.

[0128] Exemplarily, the second external fixing portion 223 and the first external fixing portion 213 can both be fixed to the shell 1 by riveting, that is, the shape of the first external fixing portion 213 before and after riveting is different. Before riveting, the first external fixing portion 213 is set corresponding to the first mounting hole 111, but after riveting, the first external fixing portion 213 extends in a direction away from the center axis of the first mounting hole 111 and abuts against the outside of the shell 1. Similarly, the shape of the second external fixing portion 223 before and after riveting is different. Before riveting, the second external fixing portion 223 is set corresponding to the second mounting hole 112, but after riveting, the second external fixing portion 223 extends in a direction away from the center axis of the second mounting hole 112 and abuts against the outside of the shell 1.

[0129] When the material strength of the first external fixing portion 213 is set to be smaller than the material strength of the second external fixing portion 223, the wall thickness t5 of the first external fixing portion 213 is greater than the wall thickness t6 of the second external fixing portion 223, and when the wall thickness of the first external fixing portion 213 makes the abutment reliability of the first external fixing portion 213 meet the requirements, by setting the wall thickness of the second external fixing portion 223 to be smaller than the wall thickness of the first external fixing portion 213, the abutment reliability of the second external fixing portion 223 can also meet the requirements, and at the same time, the material cost and weight of the second pole 22 can be reduced.

[0130] In some embodiments, as shown in Figures 4, 7, 8, and 10, the housing 1 has a first mounting hole 111 through which the first penetration portion 211 is penetrated. The first penetration portion 211 includes a first surrounding wall portion 2113 extending along the circumference of the first mounting hole 111. A first receiving groove 2111 is formed in the first surrounding wall portion 2113. That is, the first surrounding wall portion 2113 and the first end wall portion 2112 jointly define the first receiving groove 2111. The housing 1 has a second mounting hole 112 through which the second penetration portion 221 is penetrated. The second penetration portion 221 includes a second surrounding wall portion 2213 extending along the circumference of the second mounting hole 112. A second receiving groove 2211 is formed in the second surrounding wall portion 2213. That is, the second surrounding wall portion 2213 and the second end wall portion 2212 jointly define the second receiving groove 2211. The material strength of the first surrounding wall portion 2113 is less than that of the second surrounding wall portion 2213 , and the wall thickness t7 of the first surrounding wall portion 2113 is greater than the wall thickness t8 of the second surrounding wall portion 2213 .

[0131] In this way, since the material strength of the first surrounding wall portion 2113 is less than the material strength of the second surrounding wall portion 2213, when the wall thickness of the first surrounding wall portion 2113 makes the structural strength of the first surrounding wall portion 2113 meet the requirements, by setting the wall thickness of the second surrounding wall portion 2213 to be smaller than the wall thickness of the first surrounding wall portion 2113, the structural strength of the second surrounding wall portion 2213 can also meet the requirements. Therefore, by thinning the second surrounding wall portion 2213 relative to the first surrounding wall portion 2113, the material cost and weight of the second pole 22 can be reduced while meeting the structural strength requirements, and the volume of the second accommodating groove 2211 can be increased, as well as the area of ​​the second end wall portion 2212 can be increased, which is conducive to increasing the welding area between the second end wall portion 2212 and the second conductive portion 422, thereby improving the current flow capacity.

[0132] In some embodiments, the first pole 21 is a single piece made of the same main material throughout, and the second pole 22 is a single piece made of the same main material throughout. The material strength of the second pole 22 is greater than the material strength of the first pole 21. This can reduce the processing difficulty and manufacturing cost of the first pole 21 and the second pole 22. Furthermore, it can be easily achieved that the material strength of the second pole 22 is greater than that of the first pole 21 at all locations, thereby further reducing the wall thickness of the second pole 22 and further facilitating the reduction of the material cost and weight of the second pole 22.

[0133] For example, the first electrode 21 is a positive electrode, and the main material of the first electrode 21 is aluminum. The second electrode 22 is a negative electrode, and the main material of the second electrode 22 is copper. That is, the main material of the positive electrode can be aluminum, and the main material of the negative electrode can be copper. Because the material strength of aluminum is lower than that of copper, or in other words, the material strength of copper is higher than that of aluminum, the requirement that the material strength of the negative electrode is greater than that of the positive electrode can be met, which helps reduce the material cost and weight of the negative electrode.

[0134] For example, when the first pole 21 is a positive pole and the main material of the first pole 21 is aluminum, and the second pole 22 is a negative pole and the main material of the second pole 22 is copper, during the simulation of inflation, the first end wall portion 2112 of the positive pole with weaker material strength corresponds to the first receiving groove 2111, which is easy to deform. The thickness of the first end wall portion 2112 cannot be too small, and the penetration depth of the welding between the first end wall portion 2112 and the first conductive portion 421 needs to be large to meet the welding requirements. However, the material strength of the negative pole is relatively strong. The strength is relatively strong, and the second end wall portion 2212 of the negative electrode column is not easy to deform even if the wall thickness is smaller than the wall thickness of the first end wall portion 2112 of the positive electrode column, and the second end wall portion 2212 can also meet the welding requirements with the second conductive portion 422. In addition, the thickness of the first internal fixing portion 212 of the positive electrode column with weaker material strength needs to be larger to meet the pressure resistance level. Therefore, the thickness of the first internal fixing portion 212 will directly determine the capacity of the battery cell 102, so the thickness of the first internal fixing portion 212 cannot be too large. Based on the above considerations, some embodiments of the present application set the wall thickness of the first end wall portion 2112 of the positive electrode column to be greater than the wall thickness of the first internal fixing portion 212, thereby reducing the deformation of the first end wall portion 2112, increasing the welding penetration depth between the first end wall portion 2112 and the first conductive portion 421, and reducing the thickness of the first internal fixing portion 212 to increase the capacity of the battery cell 102 and reduce costs. By setting the wall thickness of the second end wall portion 2212 of the negative electrode column to be smaller than the wall thickness of the second internal fixing portion 222, and the wall thickness of the second internal fixing portion 222 to be smaller than the wall thickness of the first internal fixing portion 212, the material cost and weight of the second electrode column 22 can be reduced and the volume of the second accommodating groove 2211 can be increased while ensuring the structural strength and pressure resistance level of the second electrode column 22.

[0135] In some embodiments, as shown in Figures 8 and 10, a first pole cover plate 51 is welded to the outside of the first pole 21, the first pole cover plate 51 is an aluminum cover plate and is suitable for welding to the busbar component, and a second pole cover plate 52 is welded to the outside of the second pole 22, the second pole cover plate 52 is a copper-aluminum composite cover plate and is welded to the second pole 22 through the copper portion 521, and the aluminum portion 522 of the second pole cover plate 52 is suitable for welding to the busbar component.

[0136] In the above technical solution, the first pole cover 51 and the first pole 21 can be welded with aluminum-aluminum, which is conducive to the welding of the first pole cover 51 and the first pole 21, and the second pole cover 52 and the second pole 22 can be welded with copper-copper, which is conducive to the welding of the second pole cover 52 and the second pole 22, and the busbar component is usually made of aluminum, so the first pole cover 51 and the busbar component can be welded with aluminum-aluminum, which is conducive to the welding of the first pole cover 51 and the busbar component. At the same time, the second pole cover 52 and the busbar component can also be welded with aluminum-aluminum, which is conducive to the welding of the second pole cover 52 and the busbar component.

[0137] In some embodiments, as shown in Figures 3 to 5, the shell 1 includes a first shell wall 11, and the first pole 21 and the second pole 22 are both provided on the first shell wall 11. In this way, processing can be simplified, processing difficulty can be reduced, and processing efficiency can be improved. In addition, the axial directions of the first pole 21 and the second pole 22 are consistent with the height direction of the battery cell 102, and the first internal fixing portion 212 and the second internal fixing portion 222 both occupy the height space on the same side of the shell 1. The height space occupied by the two has an overlapping portion. Compared with arranging the first pole 21 and the second pole 22 on opposite sides, the height space occupied in the shell 1 can be reduced, which is conducive to increasing the capacity of the battery.

[0138] According to the second embodiment of the present application, the present embodiment further provides a battery 100, comprising a battery cell 102 according to any of the above-described solutions. It is worth noting that the battery 100 according to the embodiment of the present application may or may not include a housing 101. Therefore, since the reliability of the battery cell 102 according to the embodiment of the present application is improved and the cost is reduced, this is conducive to improving the performance of the battery 100 and reducing the cost of the battery 100.

[0139] For example, the battery may further include a busbar component, and there are multiple battery cells 102, and at least two of them are electrically connected via the busbar component. This allows for the series and / or parallel connection of multiple battery cells 102. For example, when multiple battery cells 102 are connected in series, the anode terminal cover of one battery cell 102 is connected to the cathode terminal cover of the next battery cell 102 via one busbar component, while the cathode terminal cover of the battery cell 102 is connected to the anode terminal cover of the previous battery cell 102 via another busbar component.

[0140] According to a third embodiment of the present application, an embodiment of the present application further provides an electrical device, comprising a battery 100 according to any of the above-described solutions, wherein the battery 100 is configured to provide electrical energy to the electrical device. The electrical device may be any of the aforementioned devices or systems employing the battery, such as a vehicle 1000. The improved performance of the battery 100 is beneficial for improving the operating power performance of the electrical device, and the reduced cost of the battery 100 is beneficial for reducing the cost of the electrical device.

[0141] Next, a battery cell 102 according to a specific embodiment of the present application is described.

[0142] The battery cell 102 includes a housing 1, a first electrode 21, and a second electrode 22. The housing 1 includes a first housing wall 11, and the first electrode 21 and the second electrode 22 are both located on the first housing wall 11. The first electrode 21 is an aluminum positive electrode, and the second electrode 22 is a copper negative electrode. In addition, the first housing wall 11 is provided with a pressure relief structure 7 located between the first electrode 21 and the second electrode 22. A sealed insulating assembly 3 is provided between the first electrode 21, the second electrode 22, and the first housing wall 11. The sealed insulating assembly 3 includes: a first insulating member 31 located on the inside of the first housing wall 11, a second insulating member 32 located on the outside of the first housing wall 11, and a sealing ring 33 located on the inside of the first housing wall 11.

[0143] The first pole 21 includes a first penetration portion 211 that penetrates the housing 1, and a first inner fixing portion 212 and a first outer fixing portion 213 that are connected to the first penetration portion 211 and are respectively disposed on the inner and outer sides of the housing 1. The housing 1 has a first mounting hole 111 through which the first penetration portion 211 penetrates. The first penetration portion 211 includes a first surrounding wall portion 2113 that extends along the circumference of the first mounting hole 111. The first penetration portion 211 includes a first end wall portion 2112 disposed on the first surrounding wall portion 2113 near the inner side of the housing 1. A first receiving groove 2111 that opens toward the outer side of the housing 1 is formed between the first surrounding wall portion 2113 and the first end wall portion 2112.

[0144] The second pole 22 includes a second penetration portion 221 that penetrates the housing 1, and a second inner fixing portion 222 and a second outer fixing portion 223 that are connected to the second penetration portion 221 and are respectively disposed on the inner and outer sides of the housing 1. The housing 1 has a second mounting hole 112 for the second penetration portion 221 to penetrate. The second penetration portion 221 includes a second surrounding wall portion 2213 that extends along the circumference of the second mounting hole 112. The second penetration portion 221 includes a second end wall portion 2212 that is disposed on the second surrounding wall portion 2213 and is close to the inner side of the housing 1. A second receiving slot 2211 that opens toward the outer side of the housing 1 is formed between the second surrounding wall portion 2213 and the second end wall portion 2212.

[0145] The wall thickness t1 of the first inner fixing portion 212 is greater than the wall thickness t2 of the second inner fixing portion 222 (i.e., t1>t2), the wall thickness t3 of the first end wall portion 2112 is greater than the wall thickness t1 of the first inner fixing portion 212 (i.e., t3>t1), the wall thickness t4 of the second end wall portion 2212 is less than the wall thickness t2 of the second inner fixing portion 222 (i.e., t2>t4), the wall thickness t3 of the first end wall portion 2112 is greater than the wall thickness t4 of the second end wall portion 2212 (i.e., t3>t1>t2>t4.

[0146] During the simulated inflation process, the first end wall portion 2112 of the positive electrode pole with weaker material strength corresponds to the first accommodating groove 2111, and the thickness of the first end wall portion 2112 cannot be too small, and the penetration depth of the welding between the first end wall portion 2112 and the first conductive portion 421 needs to be larger to meet the welding requirements. However, the material strength of the negative electrode pole is stronger, and the wall thickness of the second end wall portion 2212 of the negative electrode pole is not easy to deform even if it is smaller than the wall thickness of the first end wall portion 2112 of the positive electrode pole, and the second end wall portion 2212 can also meet the welding requirements with the second conductive portion 422. In addition, the thickness of the first internal fixing portion 212 of the positive electrode pole with weaker material strength needs to be larger to meet the pressure resistance level. Therefore, the thickness of the first internal fixing portion 212 will directly determine the capacity of the battery cell 102, and the thickness of the first internal fixing portion 212 cannot be too large. Based on the above considerations, some embodiments of the present application set the wall thickness of the first end wall portion 2112 of the positive electrode column to be greater than the wall thickness of the first internal fixing portion 212, thereby reducing the deformation of the first end wall portion 2112, increasing the welding penetration depth between the first end wall portion 2112 and the first conductive portion 421, and reducing the thickness of the first internal fixing portion 212 to increase the capacity of the battery cell 102 and reduce costs. By setting the wall thickness of the second end wall portion 2212 of the negative electrode column to be smaller than the wall thickness of the second internal fixing portion 222, and the wall thickness of the second internal fixing portion 222 to be smaller than the wall thickness of the first internal fixing portion 212, the material cost and weight of the second electrode column 22 can be reduced and the volume of the second accommodating groove 2211 can be increased while ensuring the structural strength and pressure resistance level of the second electrode column 22.

[0147] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0148] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, wherein, Comprising: A housing; A first pole column, including a first penetrating portion penetrating through the housing, and a first inner fixing portion and a first outer fixing portion connected to the first penetrating portion and respectively disposed on the inner and outer sides of the housing; A second pole column, including a second penetrating portion penetrating through the housing, and a second inner fixing portion and a second outer fixing portion connected to the second penetrating portion and respectively disposed on the inner and outer sides of the housing; Wherein, the material strength of the first inner fixing portion is less than that of the second inner fixing portion, and the wall thickness of the first inner fixing portion is greater than that of the second inner fixing portion.

2. The battery cell according to claim 1, wherein, The first penetrating portion defines a first receiving groove, the first receiving groove opens towards the inner or outer side of the housing, the first penetrating portion includes a first end wall portion oppositely disposed to the opening of the first receiving groove, the first inner fixing portion has the same main material as the first end wall portion, and the wall thickness of the first end wall portion is greater than that of the first inner fixing portion.

3. The battery cell according to claim 2, wherein, A first through hole communicating the inner side of the housing with the first receiving groove is formed on the first end wall portion. The cell assembly of the battery cell includes a first conductive portion electrically connected to the first pole column. The first conductive portion penetrates through the first through hole and includes a first connecting section received in the first receiving groove. The first connecting section overlaps on the first end wall portion and is welded to the first end wall portion.

4. The battery cell according to claim 2 or 3, wherein, The first end wall portion is disposed relatively close to the inner side of the housing with respect to the first receiving groove, and the inner end surface of the first inner fixing portion is flush with the inner end surface of the first end wall portion.

5. The battery cell according to any one of claims 2-4, wherein, The first end wall portion is made of aluminum with a wall thickness of 2.2 mm to 0.8 mm, and the wall thickness of the first inner fixing portion is 2 mm to 0.8 mm.

6. The battery cell according to claim 5, wherein, The wall thickness of the first end wall portion is 2.2 mm, and the wall thickness of the first inner fixing portion is 2 mm.

7. The battery cell according to any one of claims 1-6, wherein, The second penetrating portion defines a second receiving groove, the second receiving groove opens towards the inner or outer side of the housing, the second penetrating portion includes a second end wall portion oppositely disposed to the opening of the second receiving groove, the second inner fixing portion has the same main material as the second end wall portion, and the wall thickness of the second end wall portion is less than that of the second inner fixing portion.

8. The battery cell according to claim 7, wherein, A second through hole communicating the inner side of the housing with the second receiving groove is formed on the second end wall portion. The cell assembly of the battery cell includes a second conductive portion of the second pole column. The second conductive portion penetrates through the second through hole and includes a second connecting section received in the second receiving groove. The second connecting section overlaps on the second end wall portion and is welded to the second end wall portion.

9. The battery cell according to claim 7 or 8, wherein, The second end wall portion is disposed relatively close to the inner side of the housing with respect to the second receiving groove, and the inner end surface of the second inner fixing portion is flush with the inner end surface of the second end wall portion.

10. The battery cell according to any one of claims 7-9, wherein, The second end wall portion is made of copper with a wall thickness of 1.3 mm to 0.8 mm, and the wall thickness of the second inner fixing portion is 1.6 mm to 0.8 mm.

11. The battery cell according to claim 10, wherein, The wall thickness of the second end wall portion is 1.2 mm, and the wall thickness of the second inner fixing portion is 1.5 mm.

12. The battery cell according to any one of claims 1-11, wherein, The first penetrating portion defines a first receiving groove, the first receiving groove opening towards the inner or outer side of the housing. The first penetrating portion includes a first end wall portion disposed opposite to the opening of the first receiving groove. The second penetrating portion defines a second receiving groove, the second receiving groove opening towards the inner or outer side of the housing. The second penetrating portion includes a second end wall portion disposed opposite to the opening of the second receiving groove. Wherein, the material strength of the first end wall portion is less than that of the second end wall portion, and the wall thickness of the first end wall portion is greater than that of the second end wall portion.

13. The battery cell according to any one of claims 1-12, wherein, The material strength of the first outer fixing portion is less than that of the second outer fixing portion, and the wall thickness of the first outer fixing portion is greater than that of the second outer fixing portion.

14. The battery cell according to any one of claims 1-13, wherein, The housing has a first mounting hole for the first penetrating portion to penetrate. The first penetrating portion includes a first surrounding wall portion extending along the circumference of the first mounting hole, and a first receiving groove is formed within the first surrounding wall portion. The housing has a second mounting hole for the second penetrating portion to penetrate. The second penetrating portion includes a second surrounding wall portion extending along the circumference of the second mounting hole, and a second receiving groove is formed within the second surrounding wall portion. Wherein, the material strength of the first surrounding wall portion is less than that of the second surrounding wall portion, and the wall thickness of the first surrounding wall portion is greater than that of the second surrounding wall portion.

15. The battery cell according to any one of claims 1-14, wherein, The first pole column is an integral part with the same main material throughout, and the second pole column is an integral part with the same main material throughout. The material strength of the second pole column is greater than that of the first pole column.

16. The battery cell according to claim 15, wherein, The first pole column is a positive pole column, the main material of the first pole column is aluminum, the second pole column is a negative pole column, and the main material of the second pole column is copper.

17. The battery cell according to claim 16, wherein, A first pole column cover plate is welded outside the first pole column. The first pole column cover plate is an aluminum cover plate and is suitable for welding with a busbar component. A second pole column cover plate is welded outside the second pole column. The second pole column cover plate is a copper-aluminum composite cover plate and is welded to the second pole column through its copper part. The aluminum part of the second pole column cover plate is suitable for welding with a busbar component.

18. The battery cell according to any one of claims 1-17, wherein, The housing includes a first shell wall, and both the first pole column and the second pole column are disposed on the first shell wall.

19. A battery, wherein, Including a battery cell according to any one of claims 1-18.

20. An electrical device, wherein, Including a battery according to claim 19.

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