Battery cell, battery device, and electric device

Abstract

This application provides a battery cell, a battery device, and an electrical device, belonging to the field of battery technology. The battery cell includes a casing, an electrode assembly, and a reinforcing member. The casing includes a housing and a first end cap. One end of the housing has a first opening in a first direction, and the first end cap is welded to the housing and closes the first opening. The electrode assembly is housed within the casing. The reinforcing member protrudes from the inner circumferential surface of the housing and extends circumferentially along the first end cap. The reinforcing member is located on the side of the first end cap facing the electrode assembly in the first direction. The first end cap has a first outer circumferential surface that abuts against the inner circumferential surface of the housing. In a projection plane perpendicular to the first direction, at least a portion of the orthographic projection of the first outer circumferential surface lies within the orthographic projection of the reinforcing member. This allows the reinforcing member to improve the deformation resistance of the housing and reduce the impact of thermal runaway gases on the welded position of the first end cap and the housing, thereby reducing the risk of connection failure between the first end cap and the housing during use.

Description

Technical Field

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

[0002] In recent years, new energy vehicles have experienced rapid development. In the field of electric vehicles, power batteries, as the power source, play an irreplaceable and crucial role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also increasing. Among them, battery devices, as core components of new energy vehicles, have high requirements in terms of stability and reliability in use.

[0003] In battery technology, a battery cell in a battery device typically includes a casing and an electrode assembly housed within the casing. The casing includes a housing and end caps, which are connected and overlapped to form a sealed space for housing the electrode assembly. However, during the use of a battery cell, especially during thermal runaway, the connection between the housing and end caps is prone to failure, which can lead to risks such as explosion or leakage, thus hindering the reliability of the battery cell. Utility Model Content

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

[0005] In a first aspect, embodiments of this application provide a battery cell, including a housing, an electrode assembly, and a reinforcing member; the housing includes a shell and a first end cap, one end of the shell having a first opening in a first direction, the first end cap being welded to the shell and closing the first opening; the electrode assembly being housed within the housing; the reinforcing member protruding from the inner circumferential surface of the shell and extending circumferentially along the first end cap, and the reinforcing member being located on the side of the first end cap facing the electrode assembly in the first direction; at least a portion of the first end cap being inserted into the shell through the first opening, and the first end cap having a first outer circumferential surface abutting against the inner circumferential surface of the shell, and at least a portion of the orthographic projection of the first outer circumferential surface being located within the orthographic projection of the reinforcing member in a projection plane perpendicular to the first direction.

[0006] In the above technical solution, by providing a reinforcing member protruding from the inner circumferential surface of the housing, and the reinforcing member having a structure extending circumferentially along the first end cap, and at least a portion of the orthographic projection of the first outer circumferential surface of the first end cap and the inner circumferential surface of the housing in a projection plane perpendicular to the first direction lies within the orthographic projection of the reinforcing member in the projection plane perpendicular to the first direction, on the one hand, the reinforcing member can improve the structural strength of the housing, thereby enhancing the housing's resistance to deformation during use. This can alleviate the expansion and contraction of the housing during the use of the battery cell, which is beneficial to reducing the pulling and stress effects of the housing on the welding position of the first end cap and the housing. On the other hand, the reinforcing member can provide a certain shielding effect on the gap between the first outer circumferential surface of the first end cap and the inner circumferential surface of the housing. Thus, when the battery cell experiences thermal runaway, the reinforcing member can alleviate the impact of the thermal runaway gas inside the housing on the welding position between the first end cap and the housing, thereby effectively reducing the connection failure of the first end cap and the housing due to pulling or thermal runaway gas impact, reducing the risk of battery cell explosion or leakage during use, and improving the reliability of the battery cell.

[0007] In some embodiments, the housing includes a sidewall extending circumferentially along the first end cap, one end of the sidewall in the first direction enclosing the first opening and being welded to the first end cap; the sidewall has two first walls disposed opposite each other in a second direction and two second walls disposed opposite each other in a third direction, the area of ​​the outer surface of the first wall is larger than the area of ​​the outer surface of the second wall, and at least one second wall is provided with the reinforcing member extending in the second direction, the first direction, the second direction and the third direction being perpendicular to each other.

[0008] In the above technical solution, the sidewall of the casing has two first walls arranged opposite each other in a second direction and two second walls arranged opposite each other in a third direction. The area of ​​the outer surface of the first wall is larger than the area of ​​the outer surface of the second wall, so that the battery cell has a square structure. The first wall of the casing is a large area of ​​the outer shell. By providing a reinforcing member on at least one second wall of the casing, the structural strength of at least one second wall of the casing can be strengthened by the reinforcing member. After the battery cell is assembled and the large area is constrained, the unconstrained second wall of the casing can be strengthened to reduce the deformation of the second wall during use. This reduces the pulling and stress effects of the second wall on the welding position of the first end cover and the casing, thereby reducing the risk of connection failure of the first end cover and the casing during use.

[0009] In some embodiments, the sidewall has opposing first and second ends in the circumferential direction of the first end cap, the first and second ends being welded together to form a solder area extending along the first direction; the solder area is located on at least one of the two second walls, and the second wall having the solder area is provided with the reinforcing member extending along the second direction.

[0010] In the above technical solution, the sidewall of the shell has a first end and a second end opposite to each other in the circumferential direction of the first end cover. The first end and the second end are welded together to form a weld area extending in the first direction, so that the sidewall is a ring structure formed by the two ends opposite to each other in the circumferential direction of the first end cover. In this case, by providing a reinforcing member on the second wall with the weld area, the reinforcing member can strengthen the weld position of the sidewall itself, thereby strengthening the structural strength of the relatively weaker second wall among the two second walls of the sidewall. This can reduce the deformation of the second wall with the weld area during use. In addition, it can reduce the pulling of the second wall on the weld position of the first end cover and the shell, and also reduce the deformation, damage or cracking of the weld area of ​​the sidewall during use. This can further reduce the risk of explosion or leakage of the battery cell during use, and help to further improve the reliability of the battery cell.

[0011] In some embodiments, at least one of the first walls is provided with the reinforcing member extending in the third direction.

[0012] In the above technical solution, by providing a reinforcing member on at least one first wall of the shell, the structural strength of at least one first wall of the shell can be strengthened by the reinforcing member, thereby further increasing the overall structural strength of the shell, further reducing the deformation phenomenon of the shell during use, which is beneficial to further reduce the tensile and stress effects of the shell on the welding position of the first end cover and the shell, and further reducing the impact of thermal runaway gas inside the shell on the welding position between the first end cover and the shell, thereby further reducing the risk of connection failure of the first end cover and the shell during use.

[0013] In some embodiments, the reinforcement is an annular structure extending circumferentially along the first end cap.

[0014] In the above technical solution, by setting the reinforcing member as an annular structure extending circumferentially along the first end cover, the inner circumferential surface of the housing is provided with the reinforcing member protruding along the entire circumference of the first end cover. This can further improve the structural strength of the housing and enhance its resistance to deformation during use. This can further alleviate the expansion and contraction of the housing during the use of the battery cell, which is beneficial to further reduce the pulling and stress effects of the housing on the welding position of the first end cover and the housing. It can also improve the shielding effect of the reinforcing member on the welding position between the first end cover and the housing, which is beneficial to further reduce the impact of thermal runaway gas inside the housing on the welding position between the first end cover and the housing, thereby further reducing the risk of connection failure of the first end cover and the housing during use.

[0015] In some embodiments, along the first direction, the minimum distance between the reinforcing member and the first end cap is L1, satisfying that 0mm≤L1≤10mm.

[0016] In the above technical solution, by setting the minimum distance between the reinforcing member and the first end cap in the first direction to less than or equal to 10mm, the reinforcing member is positioned relatively close to the first end cap in the first direction. This allows the reinforcing member to be close to the welding position of the first end cap and the housing in the first direction, thereby strengthening the structural strength of the area where the housing and the first end cap are welded together. This effectively alleviates the deformation of the area where the housing and the first end cap are welded together during the use of the battery cell, further reducing the pulling and stress effects of the housing on the welding position of the first end cap and the housing. It also improves the shielding effect of the reinforcing member on the welding position between the first end cap and the housing, further reducing the impact of thermal runaway gas inside the housing on the welding position between the first end cap and the housing. This further helps to reduce the risk of connection failure between the first end cap and the housing during use.

[0017] In some embodiments, the reinforcement abuts against the first end cap along the first direction.

[0018] In the above technical solution, by setting the reinforcing member and the first end cap to abut against each other in the first direction, the reinforcing member can be moved closer to the welding position of the first end cap and the housing in the first direction, thereby improving the reinforcing effect of the reinforcing member on the area where the housing and the first end cap are welded together. In the process of using the battery cell, the deformation phenomenon of the area where the housing and the first end cap are welded together can be further alleviated, thereby further reducing the pulling and stress effects of the housing on the welding position of the first end cap and the housing. It can also further improve the shielding effect of the reinforcing member on the welding position between the first end cap and the housing, thereby further reducing the impact of thermal runaway gas inside the housing on the welding position between the first end cap and the housing. This is conducive to further reducing the risk of connection failure of the first end cap and the housing during use.

[0019] In some embodiments, the first end cap is provided with a pressure relief component, which is configured to release the internal pressure of the battery cell; in a projection plane perpendicular to the first direction, at least a portion of the orthographic projection of the reinforcement is located within the orthographic projection of the first end cap.

[0020] In the above technical solution, by setting the pressure relief component on the first end cover, the thermal runaway gas inside the casing flows from the gap between the electrode assembly and the casing to the first end cover and is then released through the pressure relief component when the battery cell experiences thermal runaway. This structure allows the reinforcing member, when close to the welding position of the first end cover and the casing in the first direction, to also change the flow direction of the thermal runaway gas as it flows from inside the casing to the first end cover. This mitigates the phenomenon of the thermal runaway gas directly impacting the welding position of the first end cover and the casing, and further reduces the phenomenon of connection failure between the first end cover and the casing due to the high temperature impact of the thermal runaway gas. This helps to further reduce the risk of battery cell explosion or leakage, and also helps to reduce the risk of thermal propagation during thermal runaway, thereby further improving the reliability of the battery cell.

[0021] In some embodiments, the reinforcement has a first surface facing away from the first end cap in the first direction, and the reinforcement has a second surface facing away from the inner circumferential surface of the housing, the first surface and the second surface being connected by a guide ramp.

[0022] In the above technical solution, by setting a guiding slope between the first and second surfaces of the reinforcing member, the guiding slope can guide the thermal runaway gas in the process of the thermal runaway gas flowing from the inside of the shell to the first end cap. This not only reduces the direct impact of thermal runaway gas on the welding position of the first end cap and the shell, but also reduces the excessive obstruction of thermal runaway gas by the reinforcing member. In this way, the internal venting smoothness of the battery cell can be improved, thereby reducing the risk of thermal runaway gas accumulating inside the shell and causing the battery cell to not depressurize in time.

[0023] In some embodiments, the reinforcing member intersects the guide ramp at a cross section perpendicular to its extension direction to form an intersection line, the intersection line comprising a straight line or an arc.

[0024] In the above technical solution, by setting the intersection line formed by the cross section of the reinforcing member perpendicular to its extension direction and the guide slope to be a straight line or an arc, the guide slope can be an inclined planar structure or an arc structure, thereby improving the guiding effect of the guide slope on the thermal runaway gas and reducing the difficulty of setting the guide slope on the reinforcing member.

[0025] In some embodiments, the reinforcing member protrudes from the inner circumferential surface of the housing by a dimension D1, satisfying 0.1mm≤D1≤10mm.

[0026] In the above technical solution, on the one hand, setting the size of the reinforcing member protruding from the inner circumference of the shell to be greater than or equal to 0.1mm is beneficial to improving the reinforcing effect of the reinforcing member on the structural strength of the shell, and can also improve the effect of the reinforcing member on changing the flow direction of thermal runaway gas during the process of thermal runaway gas flowing to the first end cover. This can further alleviate the expansion and contraction of the shell during use, and further reduce the phenomenon of thermal runaway gas directly impacting the welding position of the first end cover and the shell, so as to further reduce the risk of connection failure of the first end cover and the shell during use. On the other hand, setting the size of the reinforcing member protruding from the inner circumference of the shell to be less than or equal to 10mm is beneficial to reducing the space occupied by the reinforcing member in the shell, thereby improving the internal space utilization of the battery cell, and can also reduce the excessive obstruction of thermal runaway gas by the reinforcing member, which is beneficial to improving the internal venting smoothness of the battery cell.

[0027] In some embodiments, the electrode assembly includes a main body and a tab protruding from the main body. Along the first direction, the reinforcing member and the main body are spaced apart, and the reinforcing member is closer to the first end cap than the main body.

[0028] In the above technical solution, by setting the main body of the reinforcing member and the electrode assembly to be arranged at intervals along the first direction, and the reinforcing member being a structure that is closer to the first end cap in the first direction than the main body, the reinforcing member is arranged between the first end cap and the main body in the first direction. This reduces the interference between the reinforcing member and the main body of the electrode assembly, which helps to reduce the difficulty of assembling the electrode assembly into the housing, and also reduces the impact of bumps on the main body of the reinforcing member and the electrode assembly during use, thus reducing the risk of damage to the electrode assembly during use.

[0029] In some embodiments, the electrode assembly includes a main body and tabs protruding from the main body. In a projection plane perpendicular to the first direction, the orthographic projection of the reinforcing member is located outside the orthographic projection of the main body and is arranged at intervals.

[0030] In the above technical solution, by setting the orthographic projection of the reinforcing member in the projection plane perpendicular to the first direction as located outside the orthographic projection of the main body of the electrode assembly in the projection plane perpendicular to the first direction and spaced apart, the size of the reinforcing member protruding from the inner circumferential surface of the housing is smaller than the distance between the housing and the main body of the electrode assembly. This reduces the interference between the reinforcing member and the main body of the electrode assembly, which helps to reduce the difficulty of assembling the electrode assembly into the housing, and also reduces the impact of bumps on the reinforcing member and the main body of the electrode assembly during use, thus reducing the risk of damage to the electrode assembly during use.

[0031] In some embodiments, the dimension of the reinforcing member in the first direction is D2, satisfying 0.1mm≤D2≤10mm.

[0032] In the above technical solution, on the one hand, setting the size of the reinforcing member in the first direction to be greater than or equal to 0.1 mm is beneficial to improving the reinforcing effect of the reinforcing member on the structural strength of the shell, thereby further mitigating the expansion and contraction of the shell during use, and further reducing the risk of connection failure between the first end cap and the shell during use. On the other hand, setting the size of the reinforcing member in the first direction to be less than or equal to 10 mm is beneficial to reducing the space occupied by the reinforcing member in the shell, thereby improving the internal space utilization of the battery cell, and reducing the difficulty of protruding the reinforcing member on the inner circumferential surface of the shell, thereby reducing the manufacturing difficulty of the battery cell.

[0033] In some embodiments, the reinforcing member and the housing are separately disposed but connected; or, the reinforcing member and the housing are integrally formed.

[0034] In the above technical solution, by setting the reinforcing member and the housing as separate structures, the difficulty of protruding the reinforcing member on the inner circumferential surface of the housing can be reduced, thereby reducing the manufacturing cost of the battery cell. By setting the reinforcing member and the housing as an integrally formed structure, the stability and reliability of the reinforcing member protruding on the inner circumferential surface of the housing can be improved, thereby reducing the risk of the reinforcing member falling off the housing during use, and further enhancing the reinforcing effect of the reinforcing member on the structural strength of the housing.

[0035] In some embodiments, the reinforcing member and the housing are separately disposed, and the reinforcing member is welded to the housing.

[0036] In the above technical solution, by setting the reinforcing member and the shell as separate and welded structures, the difficulty of protruding the reinforcing member on the inner circumferential surface of the shell can be reduced, while the assembly stability and connection reliability between the shell and the reinforcing member can be improved, thereby reducing the risk of the reinforcing member falling off the shell during use, and further improving the reinforcing effect of the reinforcing member on the structural strength of the shell.

[0037] In some embodiments, the material of the reinforcing member has a melting point of P1, and the material of the shell has a melting point of P2, satisfying that 0 ≤ |P1-P2| ≤ 400℃.

[0038] In the above technical solution, by setting the absolute value of the difference between the melting point of the reinforcing material and the melting point of the shell material to be less than or equal to 400℃, the melting points of the reinforcing material and the shell are relatively close or even the same, thereby reducing the melting temperature difference between the reinforcing material and the shell during welding. On the one hand, this reduces the welding difficulty between the reinforcing material and the shell, thereby reducing the manufacturing difficulty of the battery cell. On the other hand, it reduces the occurrence of phenomena such as incomplete welding or welding cracks between the reinforcing material and the shell, which is conducive to improving the welding quality between the reinforcing material and the shell.

[0039] In some embodiments, the housing is made of steel, and the reinforcing member is made of steel or a nickel-based alloy.

[0040] In the above technical solution, by setting the material of the shell to steel and the material of the reinforcing member to steel or nickel-based alloy, the structural strength of the shell is improved and the deformation of the shell during use is reduced, while the melting point difference between the reinforcing member and the shell is reduced, thereby reducing the welding difficulty between the reinforcing member and the shell and improving the welding quality between the reinforcing member and the shell.

[0041] In some embodiments, the housing is made of aluminum, and the reinforcing member is made of aluminum, aluminum alloy, or magnesium alloy.

[0042] In the above technical solution, by setting the material of the shell to aluminum and the material of the reinforcing member to aluminum, aluminum alloy or magnesium alloy, the molding difficulty of the shell is reduced, while the melting point difference between the reinforcing member and the shell is reduced, thereby reducing the welding difficulty between the reinforcing member and the shell and improving the welding quality between the reinforcing member and the shell.

[0043] In some embodiments, the outer surface of the reinforcement is covered with a heat insulation layer.

[0044] In the above technical solution, the outer surface of the reinforcing member is covered with a heat insulation layer. When the battery cell experiences thermal runaway, the heat insulation layer can play a certain role in heat insulation between the thermal runaway gas and the reinforcing member, thereby improving the thermal shock resistance of the reinforcing member. On the one hand, it can reduce the risk of damage or melting of the reinforcing member, which is conducive to improving the stability and reliability of the reinforcing member. On the other hand, it eliminates the need to use high-temperature resistant materials for the reinforcing member, thereby expanding the range of materials that can be selected for the reinforcing member. This allows for the use of reinforcing members made of different materials according to actual needs, which is beneficial to optimizing the weight of the battery cell and manufacturing costs.

[0045] In some embodiments, the thermal conductivity of the insulation layer material is λ, which satisfies 0.05W / (m·K)≤λ≤0.9W / (m·K).

[0046] In the above technical solution, on the one hand, setting the thermal conductivity of the insulation layer material to be greater than or equal to 0.05 W / (m·K) can reduce the difficulty of material selection for the insulation layer, thereby reducing the manufacturing difficulty and cost of the insulation layer. On the other hand, setting the thermal conductivity of the insulation layer material to be less than or equal to 0.9 W / (m·K) can make the insulation layer have a better insulation effect, which can further improve the insulation effect between the thermal runaway gas and the reinforcement when the battery cell experiences thermal runaway, thereby further improving the thermal shock resistance of the reinforcement.

[0047] Secondly, embodiments of this application also provide a battery device, including the aforementioned battery cell.

[0048] In some embodiments, the housing includes two first walls disposed opposite each other in a second direction and two second walls disposed opposite each other in a third direction. One end of each of the first wall and the second wall in the first direction is connected to the first end cap, and the area of ​​the outer surface of the first wall is greater than the area of ​​the outer surface of the second wall. The first direction, the second direction and the third direction are perpendicular to each other. The battery device includes a plurality of battery cells stacked along the second direction, and at least one of the second walls is provided with a reinforcing member extending along the second direction.

[0049] In the above technical solution, the sidewall of the housing has two first walls arranged opposite each other in a second direction and two second walls arranged opposite each other in a third direction. The area of ​​the outer surface of the first wall is larger than the area of ​​the outer surface of the second wall, so that the battery cell has a square structure. The first wall of the housing is a large area of ​​the outer shell. By setting the multiple battery cells of the battery device to be stacked along the second direction and providing a reinforcing member on at least one second wall of the housing, the structural strength of at least one second wall of the housing can be strengthened by the reinforcing member. Thus, after the large area of ​​the multiple battery cells is constrained along the second direction, the unconstrained second wall of the battery cell housing can be strengthened to reduce the deformation of the second wall during use. This reduces the pulling and stress effects of the second wall on the welding position of the first end cover and the housing, thereby reducing the risk of connection failure of the first end cover and the housing during use and improving the reliability of the battery device.

[0050] In some embodiments, both second walls are provided with the reinforcing member extending along the second direction.

[0051] In the above technical solution, by providing reinforcing members on both second walls of the casing, the structural strength of both second walls of the casing is strengthened by the reinforcing members. This strengthens the two unconstrained second walls of the casing of the battery cells after the large area of ​​multiple battery cells is constrained along the second direction, thereby further reducing the deformation of the casing during use. This further reduces the tensile and stress effects of the casing on the welding positions of the first end cover and the casing, thereby further reducing the risk of connection failure of the first end cover and the casing during use and improving the reliability of the battery device.

[0052] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery cell, wherein the battery cell is used to provide electrical energy. Attached Figure Description

[0053] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0055] Figure 2 Exploded views of the structure of the battery device provided in some embodiments of this application;

[0056] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0057] Figure 4 Exploded views of the structure of a single battery cell provided in some embodiments of this application;

[0058] Figure 5 A cross-sectional view of a battery cell perpendicular to a second direction provided in some embodiments of this application;

[0059] Figure 6 for Figure 5 A magnified view of part A of the shown battery cell;

[0060] Figure 7 A cross-sectional view of the casing of a battery cell provided in some embodiments of this application, perpendicular to a first direction;

[0061] Figure 8 A cross-sectional view of the casing of a battery cell provided in some embodiments of this application, perpendicular to a first direction;

[0062] Figure 9 A cross-sectional view of the casing of a battery cell provided in some embodiments of this application, perpendicular to a first direction.

[0063] Icons: 1000 - Vehicle; 100 - Battery assembly; 10 - Housing; 11 - First housing body; 12 - Second housing body; 20 - Battery cell; 21 - Outer casing; 211 - Housing; 2111 - First opening; 2112 - Second opening; 2113 - Side wall; 2113a - First wall; 2113b - Second wall; 2113c - Soldering area; 212 - First end cap; 2121 - First outer peripheral surface; 2122 - End cap body; 2123 - Limiting protrusion; 213 - Second end cap; 22 - Electrode assembly; 221 - Main body; 222 - Electrode tab; 23 - Reinforcing member; 231 - First surface; 232 - Second surface; 233 - Guide slope; 24 - Electrode terminal; 25 - Current collector; 26 - First insulating member; 27 - Second insulating member; 28 - Pressure relief member; 200 - Controller; 300 - Motor; X - First direction; Y - Second direction; Z - Third direction. Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0065] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0066] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0067] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0068] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0069] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0070] In this application, "multiple" means two or more (including two).

[0071] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0072] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0073] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, helps prevent short circuits to some extent while allowing active ions to pass through.

[0074] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0075] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0076] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0077] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 )), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0078] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0079] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0080] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0081] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0082] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0083] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0084] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0085] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0086] In some embodiments, the separator is a separator membrane. The separator membrane can be of various types, and any known porous separator membrane with good chemical and mechanical stability can be selected.

[0087] As an example, the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0088] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0089] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

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

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

[0092] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

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

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

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

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

[0097] In some implementations, the electrode assembly has a wound structure. The positive and negative electrode sheets are wound into a wound structure.

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

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

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

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

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

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

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

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

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

[0107] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include, but are not limited to, square battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0108] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0109] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0110] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0111] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0112] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0113] As an example, the enclosure may include a first enclosure body and a second enclosure body. The first enclosure body and the second enclosure body are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, which can be either sealed or unsealed. The first enclosure body may be a top cover or a bottom plate.

[0114] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0115] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0116] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0117] Battery devices possess outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide applicability, and low self-discharge coefficient, making them an important component of today's new energy development. The development of battery technology must simultaneously consider multiple design factors, such as performance parameters like energy density, cycle life, discharge capacity, and charge / discharge rate. Furthermore, the reliability of the battery device must also be taken into account.

[0118] For a typical battery cell, it usually includes a casing and an electrode assembly housed within the casing. The casing includes a housing and an end cap. The housing is a hollow structure with an opening at one end, and the end cap closes to the opening and connects to the housing to form a sealed space for accommodating the electrode assembly. In related technologies, to reduce the risk of battery cell explosion and fire during use, a pressure relief component is usually provided on the end cap of the casing to release the internal pressure of the battery cell. This allows the pressure relief component to be destroyed in the event of thermal runaway, releasing the thermal runaway gas inside the battery cell. However, during the use of the battery cell, the casing will expand and contract. Especially during thermal runaway, the expansion and contraction of the casing can cause tension at the connection between the housing and the end cap. Furthermore, the thermal runaway gas inside the casing can cause thermal shock at the connection between the housing and the end cap as it flows towards the pressure relief component. This can easily lead to connection failure between the end cap and the housing, potentially causing the battery cell to explode or leak, and even posing a risk of heat propagation, which is detrimental to improving the reliability of the battery cell.

[0119] Based on the above considerations, in order to solve the problem of low reliability in the use of battery cells, embodiments of this application provide a battery cell, which includes a housing, an electrode assembly, and a reinforcing member. The housing includes a shell and a first end cap. One end of the shell has a first opening formed therein in a first direction. The first end cap is welded to the shell and closes the first opening. The electrode assembly is housed within the shell. The reinforcing member protrudes from the inner circumferential surface of the shell and extends circumferentially along the first end cap. The reinforcing member is located on the side of the first end cap facing the electrode assembly in the first direction. At least a portion of the first end cap is inserted into the shell through the first opening, and the first end cap has a first outer circumferential surface that abuts against the inner circumferential surface of the shell. In a projection plane perpendicular to the first direction, at least a portion of the orthographic projection of the first outer circumferential surface lies within the orthographic projection of the reinforcing member.

[0120] In this type of battery cell, a reinforcing member is provided on the inner circumferential surface of the casing. This reinforcing member extends circumferentially along the first end cap, and at least a portion of the orthographic projection of the first outer circumferential surface of the first end cap, which abuts against the inner circumferential surface of the casing, lies within the orthographic projection of the reinforcing member in the same plane. This enhances the structural strength of the casing, improving its resistance to deformation during use. It also mitigates the expansion and contraction of the casing during battery cell operation, reducing the pulling and stress effects on the welded joints of the first end cap and the casing. Furthermore, the reinforcing member provides some shielding between the first outer circumferential surface of the first end cap and the inner circumferential surface of the casing. This helps to mitigate the impact of thermal runaway gas on the welded joints of the first end cap and the casing in the event of thermal runaway. Consequently, it effectively reduces the risk of connection failure due to pulling or thermal runaway gas impact, thus lowering the risk of explosion or leakage during battery cell operation and improving the reliability of the battery cell.

[0121] The battery cells disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be constructed using battery cells and battery devices disclosed in this application. This helps to alleviate the problem of connection failures that easily occur during use, thereby improving the reliability of the battery cells.

[0122] This application provides an electrical device that uses a single battery cell or battery assembly as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0123] For ease of explanation, the following embodiments will be described using a vehicle as an example of an electrical device according to an embodiment of this application.

[0124] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle 1000. The battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to supply power to the vehicle 1000; for example, the battery device 100 can serve as the operating power source or general power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 controls the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0125] In some embodiments of this application, the battery device 100 can not only serve as the operating power or power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0126] Please refer to Figure 2 and Figure 3 , Figure 2 This is an exploded view of the structure of the battery device 100 provided in some embodiments of this application. Figure 3 This is a schematic diagram of the structure of a battery cell 20 provided in some embodiments of this application. The battery device 100 includes a housing 10 and battery cells 20, which are housed within the housing 10.

[0127] The housing 10 provides assembly space for the battery cell 20, and can adopt various structures. In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, which overlap each other, and together define an assembly space for accommodating the battery cell 20. The second housing body 12 may be a hollow structure open at one end, and the first housing body 11 may be a plate-like structure, with the first housing body 11 covering the open side of the second housing body 12 so that the first housing body 11 and the second housing body 12 together define the assembly space; alternatively, the first housing body 11 and the second housing body 12 may both be hollow structures open on one side, with the open side of the first housing body 11 covering the open side of the second housing body 12.

[0128] Of course, the box 10 formed by the first box body 11 and the second box body 12 can be of various shapes, such as a cylinder, a cuboid, or a cube. For example, in... Figure 2 In the middle, the shape of box 10 is a cuboid.

[0129] In the battery device 100, there can be one or more battery cells 20 disposed within the housing 10. When there are multiple battery cells 20 disposed within the housing 10, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, in parallel, or in a mixed configuration to form battery modules, and then multiple battery modules are connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10.

[0130] In some embodiments, the battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar for connecting multiple battery cells 20 to achieve electrical connection between the multiple battery cells 20.

[0131] Each battery cell 20 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 to these. The battery cell 20 can be in the form of a cuboid, cylinder, prism, or other shapes. For example, in... Figure 3 In the middle, the battery cell 20 has a cuboid structure.

[0132] According to some embodiments of this application, refer to Figure 3 Please refer to further details. Figure 4 , Figure 5 , Figure 6 and Figure 7 , Figure 4 This is an exploded view of the structure of a battery cell 20 provided in some embodiments of this application. Figure 5 This is a cross-sectional view of a battery cell 20 provided in some embodiments of this application, perpendicular to the second direction Y. Figure 6 for Figure 5 A magnified view of part A of the battery cell 20 shown. Figure 7This is a cross-sectional view of the casing 21 of a battery cell 20 provided in some embodiments of this application, perpendicular to a first direction X. This application provides a battery cell 20, which includes a casing 21, an electrode assembly 22, and a reinforcing member 23. The casing 21 includes a housing 211 and a first end cap 212. A first opening 2111 is formed at one end of the housing 211 in the first direction X. The first end cap 212 is welded to the housing 211 and closes the first opening 2111. The electrode assembly 22 is housed within the casing 21. The reinforcing member 23 protrudes from the inner circumferential surface of the housing 211 and extends circumferentially along the first end cap 212. The reinforcing member 23 is located on the side of the first end cap 212 facing the electrode assembly 22 in the first direction X. At least a portion of the first end cap 212 is inserted into the housing 211 through the first opening 2111, and the first end cap 212 has a first outer peripheral surface 2121 that abuts against the inner peripheral surface of the housing 211. In a projection plane perpendicular to the first direction X, at least a portion of the orthographic projection of the first outer peripheral surface 2121 is located within the orthographic projection of the reinforcing member 23.

[0133] The outer shell 21 can also be used to contain electrolytes, such as electrolyte solution. The outer shell 21 can have various structural forms, such as a cylinder or a cuboid. Similarly, the outer shell 21 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy.

[0134] In this embodiment of the application, the outer shell 21 may include a housing 211 and a first end cap 212. The housing 211 has a receiving cavity inside, which is used to receive the electrode assembly 22. The receiving cavity has a first opening 2111 at one end in the first direction X. That is, the housing 211 is a hollow structure with at least one end open in the first direction X. The first end cap 212 covers the first opening 2111 of the housing 211 and forms a sealed connection to form a closed space for receiving the electrode assembly 22 and the electrolyte.

[0135] Optionally, the connection structure between the housing 211 and the first end cap 212 can be various, such as welding, bonding or snap-fitting. For example, in the embodiment of this application, a portion of the first end cap 212 is inserted into the receiving cavity from the first opening 2111 along the first direction X, and the first end cap 212 abuts against and is welded to the inner circumferential surface of the housing 211.

[0136] For example, in Figure 4In this case, the outer shell 21 may also include a second end cap 213, and the outer shell 211 has a second opening 2112 formed at the end away from the first opening 2111 in the first direction X. The second end cap 213 is connected to the outer shell 211 and closes the second opening 2112. That is, the outer shell 211 is a hollow structure with both ends open in the first direction X, and the first end cap 212 is correspondingly closed at the first opening 2111 of the outer shell 211 and forms a sealed connection. The second end cap 213 is correspondingly closed at the second opening 2112 of the outer shell 211 and forms a sealed connection, so as to form a closed space for accommodating the electrode assembly 22 and the electrolyte. That is, the outer shell 211 is an annular structure surrounding the first end cap 212 and the second end cap 213, and the outer shell 211 is a hollow structure with both ends open in the first direction X. Correspondingly, the outer shell 211 only includes a side wall 2113, which is an annular structure surrounding the first end cap 212 and the second end cap 213.

[0137] Of course, in other embodiments, the housing 211 may also have a structure in which only one end of the first direction X has a first opening 2111. Correspondingly, the housing 211 includes an integrally formed bottom wall and a side wall 2113. The bottom wall is disposed opposite to the first end cap 212, and the side wall 2113 surrounds the bottom wall. One end of the side wall 2113 in the first direction X is connected to the bottom wall, and the other end surrounds to form the first opening 2111.

[0138] Optionally, the housing 211 can be of various shapes, such as a cylinder, cuboid, or prism. The shape of the housing 211 can be determined according to the specific shape of the electrode assembly 22. For example, if the electrode assembly 22 is a cylindrical structure, a cylindrical housing 211 can be used; if the electrode assembly 22 is a cuboid structure, a cuboid housing 211 can be used. Of course, the structure of the first end cap 212 can also be various, such as a plate-like structure or a hollow structure with one end open.

[0139] For example, in this embodiment of the application, the outer shell 21 is cuboid in shape, and correspondingly, the housing 211 is cuboid in structure. The orthographic projection of the housing 211 in the projection plane perpendicular to the first direction X is rectangular, and the orthographic projection of the first end cap 212 in the projection plane perpendicular to the first direction X is also rectangular.

[0140] In this embodiment, the reinforcing member 23 serves to strengthen the structural strength of the housing 211. The reinforcing member 23 protrudes from the inner circumferential surface of the housing 211 and extends circumferentially along the first end cap 212. That is, the reinforcing member 23 is a protruding structure connected to the inner circumferential surface of the housing 211 and protruding from the inner circumferential surface of the housing 211. The reinforcing member 23 is a strip structure or annular structure extending circumferentially along the first end cap 212. It should be noted that the inner circumferential surface of the housing 211 is the inner circumferential surface of the side wall 2113 of the housing 211. In other words, the inner circumferential surface of the housing 211 is the surface of the side wall 2113 of the housing 211 facing the electrode assembly 22.

[0141] The reinforcing member 23 is located on the side of the first end cap 212 facing the electrode assembly 22 in the first direction X. That is, the reinforcing member 23 is disposed on the inner side of the outer shell 21 formed by the housing 211 and the first end cap 212, so that both the electrode assembly 22 and the reinforcing member 23 are located inside the outer shell 21.

[0142] Optionally, the reinforcing member 23 protrudes from the inner circumferential surface of the housing 211. The reinforcing member 23 and the housing 211 can be separate and connected, or they can be integrally formed.

[0143] It should be noted that in embodiments where the outer casing 21 includes two end caps, specifically in embodiments where the outer casing 21 includes a first end cap 212 and a second end cap 213, and both the first end cap 212 and the second end cap 213 are welded to the casing 211, see the corresponding embodiment. Figure 5 As shown, two reinforcing members 23 can be provided on the inner circumferential surface of the housing 211 at intervals along the first direction X. That is, reinforcing members 23 are provided in the area where the first end cover 212 is welded to the housing 211, and reinforcing members 23 are also provided in the area where the second end cover 213 is welded to the housing 211.

[0144] At least a portion of the first end cap 212 is inserted into the housing 211 through the first opening 2111, and the first end cap 212 has a first outer peripheral surface 2121 that abuts against the inner peripheral surface of the housing 211. That is, at least a portion of the first end cap 212 is a structure located inside the housing 211, that is, at least a portion of the first end cap 212 is located inside the inner peripheral surface of the housing 211, and the surface of the first end cap 212 located inside the housing 211 that abuts against the inner peripheral surface of the housing 211 is the first outer peripheral surface 2121 of the first end cap 212.

[0145] exist Figure 6In the first end cap 212, there are an end cap body 2122 and a limiting protrusion 2123. A portion of the end cap body 2122 is inserted into the housing 211 through the first opening 2111 along the first direction X. The end cap body 2122 has a first outer peripheral surface 2121, that is, the entire outer peripheral surface of the end cap body 2122 is the first outer peripheral surface 2121. Correspondingly, the limiting protrusion 2123 protrudes from the first outer peripheral surface 2121 and abuts against the end of the housing 211 with the first opening 2111 along the first direction X, thereby improving the assembly stability and assembly accuracy between the first end cap 212 and the housing 211.

[0146] For example, the limiting protrusion 2123 is an annular structure extending circumferentially along the first outer peripheral surface 2121.

[0147] It should be noted that if the first end cap 212 is integrally inserted into the housing 211, then the entire outer peripheral surface of the first end cap 212 is the first outer peripheral surface 2121.

[0148] In a projection plane perpendicular to the first direction X, at least a portion of the orthographic projection of the first outer peripheral surface 2121 lies within the orthographic projection of the reinforcing member 23. That is, the reinforcing member 23 is a structure that covers at least a portion of the first outer peripheral surface 2121 of the first end cap 212 in the first direction X, allowing the reinforcing member 23 to shield at least a portion of the gap between the first outer peripheral surface 2121 of the first end cap 212 and the inner peripheral surface of the housing 211 in the first direction X. It should be noted that if the reinforcing member 23 is an annular structure extending circumferentially along the first end cap 212 and connected end-to-end, then in a projection plane perpendicular to the first direction X, the orthographic projection of the first outer peripheral surface 2121 is entirely within the orthographic projection of the reinforcing member 23. If the reinforcing member 23 is a strip-shaped structure extending circumferentially along the first end cap 212 and spaced apart at both ends, then in a projection plane perpendicular to the first direction X, the orthographic projection of the first outer peripheral surface 2121 is a structure where the portion corresponding to the reinforcing member 23 lies within the orthographic projection of the reinforcing member 23.

[0149] In this embodiment, the structure of the electrode assembly 22 can be various. The electrode assembly 22 can be a wound structure formed by winding a positive electrode sheet, a negative electrode sheet and an separator, or a stacked structure formed by alternatingly stacking a positive electrode sheet, a negative electrode sheet and an separator. The separator is disposed between the positive electrode sheet and the negative electrode sheet to separate the positive electrode sheet and the negative electrode sheet.

[0150] For example, the separator is a separator membrane, and the main material of the separator membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.

[0151] The electrode assembly 22 includes a main body 221 and a tab 222. The main body 221 is the main component of the electrode assembly 22 used for chemical reactions to occur inside the battery cell 20. The tab 222 is connected to one end of the main body 221.

[0152] For example, the electrode assembly 22 includes two tabs 222 with opposite polarities, namely, the two tabs 222 are the positive tab and the negative tab of the electrode assembly 22. It should be noted that the tabs 222 of the electrode assembly 22 are formed by stacking and connecting regions of the positive current collector of the positive electrode sheet that are not coated with a positive active material layer, or by stacking and connecting regions of the negative current collector of the negative electrode sheet that are not coated with a negative active material layer. If the tab 222 is the positive tab of the electrode assembly 22, then the tab 222 is formed by stacking and connecting regions of the positive current collector of the positive electrode sheet that are not coated with a positive active material layer; if the tab 222 is the negative tab of the electrode assembly 22, then the tab 222 is formed by stacking and connecting regions of the negative current collector of the negative electrode sheet that are not coated with a negative active material layer.

[0153] Optionally, the electrode assembly 22 housed within the housing 21 can be one or more. For example, in... Figure 4 In this embodiment, the outer casing 21 houses two electrode assemblies 22, which are stacked along the second direction Y. Correspondingly, the second direction Y is also the thickness direction of the electrode assembly 22. Of course, in other embodiments, the electrode assembly 22 housed in the outer casing 21 may be three, four, five, or six, etc. Exemplarily, in this embodiment, the first direction X, the second direction Y, and the third direction Z are perpendicular to each other. The first direction X is the height direction of the battery cell 20, the second direction Y is the thickness direction of the battery cell 20, and the third direction Z is the length direction of the battery cell 20.

[0154] In some embodiments, see Figure 3 and Figure 4 As shown, the battery cell 20 may also include an electrode terminal 24, which is insulated and mounted on the housing 21. The electrode terminal 24 is used to electrically connect with the tab 222 of the electrode assembly 22 to output or input electrical energy of the battery cell 20.

[0155] It should be noted that the electrode terminal 24 is insulated and mounted on the housing 21, meaning that there is no electrical connection between the electrode terminal 24 and the housing 21.

[0156] In this embodiment of the application, the battery cell 20 includes two electrode terminals 24, which are disposed at a distance along the third direction Z on the second end cover 213 of the housing 21. The two electrode terminals 24 are electrically connected to two tabs 222 of opposite polarity of the electrode assembly 22, so as to realize the input or output of electrical energy of the battery cell 20.

[0157] For example, the electrode terminal 24 can be made of various materials, such as copper, iron, aluminum, steel or aluminum alloy.

[0158] In some embodiments, see Figure 5 As shown, the battery cell 20 may also include two current collectors 25. Both current collectors 25 are disposed inside the housing 21 and are spaced apart. Each current collector 25 is used to connect an electrode terminal 24 and a tab 222 of the same polarity in multiple electrode assemblies 22 to realize the electrical connection between the electrode terminal 24 and the electrode assembly 22, which helps to reduce the assembly difficulty between the tab 222 and the electrode terminal 24.

[0159] For example, the current collector 25 is welded to the tab 222. Of course, in other embodiments, the current collector 25 and the tab 222 may also be in a structure that abuts or snaps against each other.

[0160] For example, the material of the current collector 25 can be various, such as copper, iron, aluminum, steel or aluminum alloy.

[0161] In some embodiments, see Figure 5 As shown, the battery cell 20 also includes a first insulating member 26, which is disposed in the first direction X between the first end cap 212 and the electrode assembly 22 to insulate and isolate the first end cap 212 and the electrode assembly 22.

[0162] For example, the material of the first insulating element 26 may be rubber, plastic or silicone, etc.

[0163] It should be noted that in embodiments where the outer casing 21 of the battery cell 20 includes a second end cap 213, the battery cell 20 may further include a second insulating member 27, see [link to documentation]. Figure 4 and Figure 5 As shown, the second insulating member 27 is disposed between the second end cap 213 and the electrode assembly 22 in the first direction X to insulate and isolate the second end cap 213 and the electrode assembly 22.

[0164] For example, the material of the second insulating element 27 may be rubber, plastic or silicone, etc.

[0165] In this embodiment, by providing a reinforcing member 23 protruding from the inner circumferential surface of the housing 211, and the reinforcing member 23 having a structure extending circumferentially along the first end cap 212, and at least a portion of the orthographic projection of the first outer circumferential surface 2121, which abuts against the inner circumferential surface of the first end cap 212 and the housing 211, in a projection plane perpendicular to the first direction X, lies within the orthographic projection of the reinforcing member 23 in the projection plane perpendicular to the first direction X. This allows the reinforcing member 23 to enhance the structural strength of the housing 211, thereby improving the housing 211's resistance to deformation during use. Consequently, during the use of the battery cell 20, the expansion and contraction of the housing 211 can be alleviated, which is beneficial for reducing the impact of the housing 211 on the first end cap 212. The tension and stress at the welding position of the cover 212 and the shell 211, on the other hand, enable the reinforcing member 23 to provide a certain shielding effect on the gap between the first outer peripheral surface 2121 of the first end cover 212 and the inner peripheral surface of the shell 211. Thus, when the battery cell 20 experiences thermal runaway, the reinforcing member 23 can alleviate the impact of the thermal runaway gas inside the shell 21 on the welding position between the first end cover 212 and the shell 211. This can effectively reduce the connection failure of the first end cover 212 and the shell 211 due to tension or thermal runaway gas impact, thereby reducing the risk of explosion or leakage of the battery cell 20 during use and improving the reliability of the battery cell 20.

[0166] According to some embodiments of this application, see Figure 3 , Figure 4 and Figure 7 As shown, the housing 211 may include a sidewall 2113 extending circumferentially along the first end cap 212. One end of the sidewall 2113 in the first direction X forms a first opening 2111 and is welded to the first end cap 212. The sidewall 2113 has two first walls 2113a disposed opposite each other in the second direction Y and two second walls 2113b disposed opposite each other in the third direction Z. The area of ​​the outer surface of the first wall 2113a is larger than the area of ​​the outer surface of the second wall 2113b, and at least one second wall 2113b is provided with a reinforcing member 23 extending in the second direction Y. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0167] In this embodiment, the sidewall 2113 of the shell 211 is an annular structure extending circumferentially along the first end cap 212, and one end of the sidewall 2113 in the first direction X forms a first opening 2111. It should be noted that, in this embodiment, the shell 21 is a structure including two end caps, namely the first end cap 212 and the second end cap 213. Correspondingly, the shell 211 only includes the sidewall 2113, and the two ends of the sidewall 2113 in the first direction X respectively form the first opening 2111 and the second opening 2112. That is, the shell 211 is a hollow structure with openings at both ends in the first direction X. Of course, in other embodiments, if the shell 21 only includes the first end cap 212, then the shell 211 is a structure with openings at only one end in the first direction X. Correspondingly, the shell 211 also includes a bottom wall, and the sidewall 2113 is disposed around the bottom wall. One end of the sidewall 2113 in the first direction X is connected to the bottom wall, and the other end forms the first opening 2111.

[0168] The side wall 2113 has two first walls 2113a arranged opposite each other in the second direction Y and two second walls 2113b arranged opposite each other in the third direction Z. That is, the side wall 2113 is a cuboid structure. Correspondingly, the side wall 2113 has two first walls 2113a and two second walls 2113b arranged opposite each other, and one first wall 2113a, one second wall 2113b, another first wall 2113a and another second wall 2113b are connected end to end in a structure.

[0169] The area of ​​the outer surface of the first wall 2113a is greater than the area of ​​the outer surface of the second wall 2113b. In other words, the first wall 2113a is the wall with the largest outer surface area among the multiple walls of the side wall 2113, making the first wall 2113a also a large area of ​​the outer shell 21.

[0170] At least one second wall 2113b is provided with a reinforcing member 23 extending in the second direction Y. That is, only one second wall 2113b may have a reinforcing member 23 extending in the second direction Y on its inner surface facing the electrode assembly 22, or both second walls 2113b may have a reinforcing member 23 extending in the second direction Y on their inner surfaces facing the electrode assembly 22. For example, in Figure 7 In the middle, both second walls 2113b are provided with reinforcing members 23 extending along the second direction Y.

[0171] In this embodiment, the sidewall 2113 of the housing 211 has two first walls 2113a disposed opposite each other in the second direction Y and two second walls 2113b disposed opposite each other in the third direction Z. The area of ​​the outer surface of the first wall 2113a is larger than the area of ​​the outer surface of the second wall 2113b, so that the battery cell 20 has a square structure, and the first wall 2113a of the housing 211 is a large area of ​​the outer shell 21. A reinforcing member 23 is provided on at least one of the second walls 2113b of the housing 211 to make the battery cell 20 have a square structure. The structural strength of at least one second wall 2113b of the housing 211 can be strengthened by the reinforcing member 23. After the battery cell 20 is assembled and the large area is constrained, the unconstrained second wall 2113b of the housing 211 can be strengthened to reduce the deformation of the second wall 2113b during use. This reduces the tensile and stress effects of the second wall 2113b on the welding position of the first end cover 212 and the housing 211, thereby reducing the risk of connection failure between the first end cover 212 and the housing 211 during use.

[0172] In some embodiments, combined with Figure 4 and Figure 7 As shown, the sidewall 2113 has a first end and a second end opposite each other in the circumferential direction of the first end cap 212. The first end and the second end are welded together to form a solder area 2113c extending in the first direction X. The solder area 2113c is located on at least one of the two second walls 2113b, and the second wall 2113b having the solder area 2113c is provided with a reinforcing member 23 extending in the second direction Y.

[0173] The sidewall 2113 has a first end and a second end opposite to each other in the circumferential direction of the first end cover 212. The first end and the second end are welded together to form a solder area 2113c extending in the first direction X. That is, the sidewall 2113 of the shell 211 is a hollow cuboid structure with two openings in the first direction X formed by bending a metal plate, and then welding the two ends of the metal plate together in the circumferential direction of the first end cover 212. Correspondingly, the two ends of the sidewall 2113 that are welded together are the first end and the second end opposite to each other in the circumferential direction of the first end cover 212. The first end and the second end of the sidewall 2113 are stacked and welded together to form a solder area 2113c extending in the first direction X and in a strip-shaped structure on the sidewall 2113.

[0174] The solder area 2113c is located on at least one of the two second walls 2113b, and the second wall 2113b with the solder area 2113c is provided with a reinforcing member 23 extending in the second direction Y. That is, the solder area 2113c formed after the side wall 2113 is manufactured is a structure located on at least one side of the side wall 2113 in the third direction Z. Correspondingly, the second wall 2113b with the solder area 2113c is provided with a reinforcing member 23 on the inner surface facing the electrode assembly 22.

[0175] In this embodiment, the sidewall 2113 of the housing 211 has a first end and a second end opposite to each other in the circumferential direction of the first end cover 212. The first end and the second end are welded together to form a solder area 2113c extending in the first direction X. This makes the sidewall 2113 an annular structure formed by the two ends opposite to each other in the circumferential direction of the first end cover 212. A reinforcing member 23 is provided protruding on the second wall 2113b where the solder area is formed, so that the reinforcing member 23 can strengthen the solder position of the sidewall 2113 itself, thereby achieving reinforcement of both sides of the sidewall 2113. The structural strength of the relatively weaker second wall 2113b is reinforced, thereby reducing the deformation of the second wall 2113b with the welded area during use. This reduces the pulling force of the second wall 2113b on the welded position of the first end cap 212 and the shell 211, and also reduces the deformation, damage or cracking of the welded area of ​​the side wall 2113 during use. This further reduces the risk of explosion or leakage of the battery cell 20 during use, and helps to further improve the reliability of the battery cell 20.

[0176] According to some embodiments of this application, please refer to Figure 8 , Figure 8 The battery cell 20 provided in some embodiments of this application has a casing 21 with its shell perpendicular to the first direction X. At least one first wall 2113a of the sidewall 2113 is provided with a reinforcing member 23 extending in the third direction Z. That is, the side of the first wall 2113a of the sidewall 2113 facing the electrode assembly 22 may also be provided with a reinforcing member 23 extending in the third direction Z, so that the inner circumferential surface of the casing 211 has a structure with a plurality of reinforcing members 23 protruding, and the plurality of reinforcing members 23 are arranged at intervals along the circumference of the first end cap 212.

[0177] For example, each of the two first walls 2113a of the side wall 2113 is provided with a reinforcing member 23 extending in the third direction Z.

[0178] In this embodiment, by providing a reinforcing member 23 on at least one first wall 2113a of the housing 211, the structural strength of at least one first wall 2113a of the housing 211 can be strengthened by the reinforcing member 23. Thus, the overall structural strength of the housing 211 can be further increased by the reinforcing member 23, thereby further reducing the deformation of the housing 211 during use. This is beneficial to further reduce the tensile and stress effects of the housing 211 on the welding position between the first end cover 212 and the housing 211, and also beneficial to further reduce the impact of thermal runaway gas inside the housing 21 on the welding position between the first end cover 212 and the housing 211, thereby further reducing the risk of connection failure between the first end cover 212 and the housing 211 during use.

[0179] Of course, the structure of the battery cell 20 is not limited to this. In some embodiments, the battery cell 20 can also have other structures, for example, see reference. Figure 9 As shown, Figure 9 The battery cell 20 provided in some embodiments of this application has a casing 21 perpendicular to the first direction X in a cross-sectional view, and the reinforcing member 23 is an annular structure extending circumferentially along the first end cap 212.

[0180] In this embodiment, by setting the reinforcing member 23 as an annular structure extending circumferentially along the first end cap 212, the inner circumferential surface of the housing 211 is provided with the reinforcing member 23 protruding along the entire circumference of the first end cap 212. This further enhances the structural strength of the housing 211 and improves its resistance to deformation during use. This further alleviates the expansion and contraction of the housing 211 during the use of the battery cell 20, which helps to further reduce the pulling and stress effects of the housing 211 on the welding position between the first end cap 212 and the housing 211. It also enhances the shielding effect of the reinforcing member 23 on the welding position between the first end cap 212 and the housing 211, which helps to further reduce the impact of thermal runaway gas inside the outer casing 21 on the welding position between the first end cap 212 and the housing 211, thereby further reducing the risk of connection failure between the first end cap 212 and the housing 211 during use.

[0181] According to some embodiments of this application, see Figure 6 As shown, along the first direction X, the minimum distance between the reinforcing member 23 and the first end cap 212 is L1, which satisfies 0mm≤L1≤10mm.

[0182] For example, the minimum distance L1 between the reinforcing member 23 and the first end cap 212 in the first direction X can be 0mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.8mm, 1mm, 1.3mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.5mm, 2.8mm, 3mm, 3.3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm or 10mm, etc.

[0183] It should be noted that in the embodiment where the outer shell 21 includes a second end cap 213 and a reinforcing member 23 is also provided in the area where the second end cap 213 is welded to the shell 211, the minimum distance between the reinforcing member 23 corresponding to the second end cap 213 and the second end cap 213 is also 0mm to 10mm.

[0184] In this embodiment, by setting the minimum distance between the reinforcing member 23 and the first end cap 212 in the first direction X to be less than or equal to 10 mm, the reinforcing member 23 is positioned relatively close to the first end cap 212 in the first direction X. This allows the reinforcing member 23 to be close to the welding position of the first end cap 212 and the housing 211 in the first direction X, thereby strengthening the structural strength of the area where the housing 211 and the first end cap 212 are welded together. This effectively alleviates the deformation of the area where the housing 211 and the first end cap 212 are welded together during the use of the battery cell 20, further reducing the pulling and stress effects of the housing 211 on the welding position of the first end cap 212 and the housing 211. It also enhances the shielding effect of the reinforcing member 23 on the welding position between the first end cap 212 and the housing 211, further reducing the impact of thermal runaway gas inside the housing 21 on the welding position between the first end cap 212 and the housing 211. This further helps to reduce the risk of connection failure between the first end cap 212 and the housing 211 during use.

[0185] In some embodiments, along the first direction X, the reinforcing member 23 abuts against the first end cap 212, that is, the minimum distance L1 between the reinforcing member 23 and the first end cap 212 in the first direction X is 0 mm.

[0186] In this embodiment, by setting the reinforcing member 23 and the first end cap 212 to abut against each other in the first direction X, the reinforcing member 23 can be brought closer to the welding position of the first end cap 212 and the housing 211 in the first direction X. This enhances the reinforcing effect of the reinforcing member 23 on the area where the housing 211 and the first end cap 212 are welded together. Consequently, during the use of the battery cell 20, the deformation of the area where the housing 211 and the first end cap 212 are welded together can be further alleviated, thereby reducing the pulling and stress effects of the housing 211 on the welding position of the first end cap 212 and the housing 211. Furthermore, the shielding effect of the reinforcing member 23 on the welding position between the first end cap 212 and the housing 211 can be further enhanced, thereby reducing the impact of thermal runaway gas inside the housing 21 on the welding position between the first end cap 212 and the housing 211. This further helps to reduce the risk of connection failure between the first end cap 212 and the housing 211 during use.

[0187] According to some embodiments of this application, see Figure 4 , Figure 5 and Figure 6 As shown, a pressure relief component 28 is provided on the first end cap 212, which is configured to release the internal pressure of the battery cell 20. In a projection plane perpendicular to the first direction X, at least a portion of the orthographic projection of the reinforcing member 23 lies within the orthographic projection of the first end cap 212.

[0188] The first end cap 212 of the outer casing 21 is provided with a pressure relief component 28, which serves to release the internal pressure of the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value.

[0189] Optionally, the pressure relief component 28 and the first end cap 212 can be integrally formed or separate components. If the pressure relief component 28 and the first end cap 212 are separate components, the pressure relief component 28 can be connected to the first end cap 212 by welding or other means. Correspondingly, the pressure relief component 28 can be a component such as an explosion-proof valve, explosion-proof disc, gas valve, pressure relief valve, or safety valve. If the pressure relief component 28 and the first end cap 212 are integrally formed, the pressure relief component 28 is a region on the first end cap 212 with a weak structure, such as a region on the first end cap 212 with a groove, that is, the pressure relief component 28 is a part of the first end cap 212.

[0190] In the projection plane perpendicular to the first direction X, at least a portion of the orthographic projection of the reinforcing member 23 is located within the orthographic projection of the first end cap 212. That is, the projection of the reinforcing member 23 in the first direction X is a structure in which at least a portion falls into the first end cap 212, such that the first end cap 212 is a structure that covers at least a portion of the reinforcing member 23 in the first direction X.

[0191] For example, in Figure 6 In the projection plane perpendicular to the first direction X, the entire orthographic projection of the reinforcing member 23 is located within the orthographic projection of the first end cover 212.

[0192] In this embodiment, by placing the pressure relief component 28 on the first end cap 212, the thermal runaway gas inside the casing 21 flows from the gap between the electrode assembly 22 and the casing 21 to the first end cap 212 and is then released through the pressure relief component 28 when the battery cell 20 experiences thermal runaway. This structure allows the reinforcing member 23, when approaching the welding position of the first end cap 212 and the casing 211 in the first direction X, to also change the flow direction of the thermal runaway gas as it flows from inside the casing 21 to the first end cap 212. This mitigates the phenomenon of the thermal runaway gas directly impacting the welding position of the first end cap 212 and the casing 211, and further reduces the possibility of connection failure between the first end cap 212 and the casing 211 due to the high temperature impact of the thermal runaway gas. This helps to further reduce the risk of the battery cell 20 bursting or leaking, and also helps to reduce the risk of thermal propagation of the battery cell 20 during thermal runaway, thereby further improving the reliability of the battery cell 20.

[0193] According to some embodiments of this application, see Figure 6 As shown, the reinforcing member 23 has a first surface 231 facing away from the first end cap 212 in the first direction X, and the reinforcing member 23 has a second surface 232 facing away from the inner circumferential surface of the housing 211. The first surface 231 and the second surface 232 are connected by a guide slope 233.

[0194] The second surface 232 is the surface of the reinforcing member 23 facing away from the housing 211. Correspondingly, the reinforcing member 23 has one side connected to the inner circumferential surface of the housing 211, and the other side is the second surface 232. It should be noted that if the reinforcing member 23 is a structure protruding from the first wall 2113a, then the surface of the reinforcing member 23 facing away from the first wall 2113a in the second direction Y is the second surface 232. If the reinforcing member 23 is a structure protruding from the second wall 2113b, then the surface of the reinforcing member 23 facing away from the first wall 2113a in the third direction Z is the second surface 232. If the reinforcing member 23 is an annular structure extending circumferentially along the first end cap 212, then the inner circumferential surface of the reinforcing member 23 is the second surface 232 of the reinforcing member 23.

[0195] The first surface 231 and the second surface 232 are connected by a guide slope 233. That is, an inclined surface is formed between the first surface 231 and the second surface 232 of the reinforcing member 23, which is the guide slope 233.

[0196] It should be noted that in the embodiment where the outer shell 21 includes a second end cap 213 and a reinforcing member 23 is also provided in the area where the second end cap 213 is welded to the shell 211, the first surface 231 of the reinforcing member 23 corresponding to the second end cap 213 is the surface of the reinforcing member 23 corresponding to the second end cap 213 that is away from the second end cap 213 in the first direction X.

[0197] In this embodiment, by providing a guiding slope 233 between the first surface 231 and the second surface 232 of the reinforcing member 23, the guiding slope 233 can guide the thermal runaway gas in the process of the thermal runaway gas flowing from the inside of the outer casing 21 to the first end cap 212. This not only reduces the direct impact of the thermal runaway gas on the welding position between the first end cap 212 and the outer casing 211, but also reduces the excessive obstruction of the thermal runaway gas by the reinforcing member 23. In this way, the internal exhaust smoothness of the battery cell 20 can be improved, thereby reducing the risk of the battery cell 20 not depressurizing in time due to the accumulation of thermal runaway gas in the outer casing 21.

[0198] In some embodiments, please continue to see Figure 6 As shown, the cross-section of the reinforcing member 23 perpendicular to its extension direction intersects with the guide slope 233 to form an intersection line, which may be a straight line or an arc. That is, the guide slope 233 is a chamfered or rounded surface connecting the first surface 231 and the second surface 232 of the reinforcing member 23.

[0199] In this embodiment, by setting the intersection line formed by the cross section of the reinforcing member 23 perpendicular to its extension direction and the guide slope 233 to be a straight line or an arc, the guide slope 233 can be an inclined planar structure or an arc structure, thereby improving the guiding effect of the guide slope 233 on thermal runaway gas and reducing the difficulty of setting the guide slope 233 on the reinforcing member 23.

[0200] According to some embodiments of this application, please refer to Figure 6 As shown, the reinforcing member 23 protrudes from the inner circumferential surface of the housing 211 by a dimension of D1, which satisfies 0.1mm≤D1≤10mm.

[0201] Wherein, D1 is the thickness of the reinforcing member 23 protruding from the inner circumferential surface of the housing 211. If the reinforcing member 23 is a structure protruding from the first wall 2113a, then D1 is the thickness of the reinforcing member 23 in the second direction Y. If the reinforcing member 23 is a structure protruding from the second wall 2113b, then D1 is the thickness of the reinforcing member 23 in the third direction Z. If the reinforcing member 23 is an annular structure extending circumferentially along the first end cover 212, then D1 is the thickness of the reinforcing member 23 in the radial direction of the first end cover 212.

[0202] For example, the dimension D1 of the reinforcing member 23 protruding from the inner peripheral surface of the housing 211 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.8mm, 1mm, 1.3mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.5mm, 2.8mm, 3mm, 3.3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, or 10mm, etc.

[0203] In this embodiment, on the one hand, the size of the reinforcing member 23 protruding from the inner circumferential surface of the housing 211 is set to be greater than or equal to 0.1 mm. This is beneficial to improving the reinforcing effect of the reinforcing member 23 on the structural strength of the housing 211, and can also improve the effect of the reinforcing member 23 on changing the flow direction of the thermal runaway gas during the process of the thermal runaway gas flowing to the first end cover 212. This can further alleviate the expansion and contraction phenomenon of the housing 211 during use, and further reduce the phenomenon of the thermal runaway gas directly impacting the welding position of the first end cover 212 and the housing 211, so as to further reduce the risk of connection failure of the first end cover 212 and the housing 211 during use. On the other hand, the size of the reinforcing member 23 protruding from the inner circumferential surface of the housing 211 is set to be less than or equal to 10 mm. This is beneficial to reducing the space occupied by the reinforcing member 23 in the housing 21, so as to improve the internal space utilization of the battery cell 20, and can also reduce the excessive obstruction of the thermal runaway gas by the reinforcing member 23, which is beneficial to improving the internal exhaust smoothness of the battery cell 20.

[0204] According to some embodiments of this application, see Figure 4 , Figure 5 and Figure 6 As shown, the electrode assembly 22 may include a main body 221 and an electrode tab 222 protruding from the main body 221. Along the first direction X, the reinforcing member 23 and the main body 221 are arranged at intervals, and the reinforcing member 23 is closer to the first end cap 212 than the main body 221.

[0205] The reinforcing member 23 and the main body 221 are arranged at intervals, and the reinforcing member 23 is closer to the first end cap 212 than the main body 221. That is to say, in the projection plane perpendicular to the second direction Y and in the projection plane perpendicular to the third direction Z, the orthographic projection of the reinforcing member 23 and the orthographic projection of the main body 221 are non-overlapping structures, and the orthographic projection of the reinforcing member 23 is located between the orthographic projection of the main body 221 and the orthographic projection of the first end cap 212.

[0206] In some embodiments, see Figure 6As shown, along the first direction X, the minimum distance between the reinforcing member 23 and the main body 221 is L2, which satisfies 0.01mm≤L2≤11mm.

[0207] For example, the minimum distance L2 between the reinforcing member 23 and the main body 221 in the first direction X can be 0.01mm, 0.02mm, 0.05mm, 0.08mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.8mm, 1mm, 1.3mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.5mm, 2.8mm, 3mm, 3.3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, or 11mm, etc.

[0208] In this embodiment, by arranging the reinforcing member 23 and the main body 221 of the electrode assembly 22 at intervals along the first direction X, and by arranging the reinforcing member 23 closer to the first end cap 212 in the first direction X than the main body 221, the reinforcing member 23 is arranged between the first end cap 212 and the main body 221 in the first direction X. This reduces the interference between the reinforcing member 23 and the main body 221 of the electrode assembly 22, which helps to reduce the difficulty of assembling the electrode assembly 22 into the housing 21. It also reduces the impact of bumps on the reinforcing member 23 and the main body 221 of the electrode assembly 22 during use, which helps to reduce the risk of the electrode assembly 22 being damaged during use.

[0209] According to some embodiments of this application, see Figure 4 , Figure 5 and Figure 6 As shown, the electrode assembly 22 may include a main body 221 and tabs 222 protruding from the main body 221. In a projection plane perpendicular to the first direction X, the orthographic projection of the reinforcing members 23 is located outside the orthographic projection of the main body 221 and is arranged at intervals. That is, the projection of the reinforcing members 23 in the first direction X is a structure located in the gap between the main body 221 and the side wall 2113 of the housing 211.

[0210] In some embodiments, see Figure 6 As shown, in the projection plane perpendicular to the first direction X, the minimum distance between the orthographic projection of the reinforcing member 23 and the orthographic projection of the main body 221 is L3, which satisfies 0.01mm≤L3≤8mm.

[0211] For example, L3 can be 0.01mm, 0.02mm, 0.05mm, 0.08mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.8mm, 1mm, 1.3mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.5mm, 2.8mm, 3mm, 3.3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, or 8mm, etc.

[0212] In this embodiment, by setting the orthographic projection of the reinforcing member 23 in a projection plane perpendicular to the first direction X as located outside the orthographic projection of the main body portion 221 of the electrode assembly 22 in a projection plane perpendicular to the first direction X and spaced apart, the size of the reinforcing member 23 protruding from the inner circumferential surface of the housing 211 is smaller than the distance between the housing 211 and the main body portion 221 of the electrode assembly 22. This reduces the interference between the reinforcing member 23 and the main body portion 221 of the electrode assembly 22, which helps to reduce the difficulty of assembling the electrode assembly 22 into the housing 21 and reduces the impact of bumps on the reinforcing member 23 and the main body portion 221 of the electrode assembly 22 during use, thus reducing the risk of damage to the electrode assembly 22 during use.

[0213] According to some embodiments of this application, see Figure 6 As shown, the dimension of the reinforcing member 23 in the first direction X is D2, which satisfies 0.1mm≤D2≤10mm.

[0214] Wherein, D2 is the maximum thickness of the reinforcing member 23 in the first direction X.

[0215] For example, the dimension D2 of the reinforcing member 23 in the first direction X can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.8mm, 1mm, 1.3mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.5mm, 2.8mm, 3mm, 3.3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm or 10mm, etc.

[0216] In this embodiment, on the one hand, the size of the reinforcing member 23 in the first direction X is set to be greater than or equal to 0.1 mm, which is beneficial to improving the reinforcing effect of the reinforcing member 23 on the structural strength of the housing 211, thereby further alleviating the expansion and contraction of the housing 211 during use, and further reducing the risk of connection failure between the first end cap 212 and the housing 211 during use. On the other hand, the size of the reinforcing member 23 in the first direction X is set to be less than or equal to 10 mm, which is beneficial to reducing the space occupied by the reinforcing member 23 in the housing 21, thereby improving the internal space utilization of the battery cell 20, and reducing the difficulty of protruding the reinforcing member 23 on the inner circumferential surface of the housing 211, thereby reducing the manufacturing difficulty of the battery cell 20.

[0217] According to some embodiments of this application, see Figure 6 As shown, the reinforcing member 23 and the housing 211 are separately arranged and connected. That is, the reinforcing member 23 and the housing 211 are two independent parts, and the reinforcing member 23 is connected to the inner surface of the side wall 2113 of the housing 211 facing the electrode assembly 22.

[0218] For example, if both the reinforcing member 23 and the housing 211 are made of metal, the reinforcing member 23 can be connected to the inner circumferential surface of the housing 211 by welding, bonding or other structures. If the reinforcing member 23 is made of non-metallic material, the reinforcing member 23 can be connected to the inner circumferential surface of the housing 211 by bonding or other structures.

[0219] In this embodiment, by setting the reinforcing member 23 and the housing 211 as separate structures, the difficulty of protruding the reinforcing member 23 on the inner circumferential surface of the housing 211 can be reduced, thereby reducing the manufacturing cost of the battery cell 20.

[0220] Of course, in other embodiments, the battery cell 20 can also have other structures, such as the reinforcing member 23 and the housing 211 being integrally formed. That is, the reinforcing member 23 and the housing 211 are structures made using an integral forming process, such as casting, stamping, or milling.

[0221] In this embodiment, by setting the reinforcing member 23 and the housing 211 as an integrally formed structure, the stability and reliability of the reinforcing member 23 protruding on the inner circumferential surface of the housing 211 can be improved, thereby reducing the risk of the reinforcing member 23 falling off the housing 211 during use, and further improving the reinforcing effect of the reinforcing member 23 on the structural strength of the housing 211.

[0222] According to some embodiments of this application, please continue to refer to Figure 6As shown, the reinforcing member 23 and the housing 211 are separate components, and the reinforcing member 23 is welded to the housing 211. That is to say, both the reinforcing member 23 and the housing 211 are made of metal, and the reinforcing member 23 and the housing 211 are welded together.

[0223] In this embodiment, by setting the reinforcing member 23 and the housing 211 as separate and welded structures, the difficulty of protruding the reinforcing member 23 on the inner circumferential surface of the housing 211 can be reduced, while the assembly stability and connection reliability between the housing 211 and the reinforcing member 23 can be improved. This reduces the risk of the reinforcing member 23 falling off the housing 211 during use and further enhances the reinforcing effect of the reinforcing member 23 on the structural strength of the housing 211.

[0224] In some embodiments, the melting point of the material of the reinforcing member 23 is P1, and the melting point of the material of the shell 211 is P2, satisfying 0 ≤ |P1 - P2| ≤ 400℃. That is, the difference between the melting point of the material of the reinforcing member 23 and the melting point of the material of the shell 211 is within 400℃. This can be either the melting point of the material of the reinforcing member 23 being 0-400℃ higher than the melting point of the material of the shell 211, or the melting point of the material of the reinforcing member 23 being 0-400℃ lower than the melting point of the material of the shell 211.

[0225] Optionally, the coefficient of thermal expansion of the material of the reinforcing member 23 is α1, and the coefficient of thermal expansion of the material of the shell 211 is α2, satisfying that 0 ≤ |α1-α2| / min(α1,α2) ≤ 50%. That is, the ratio of the difference between the coefficient of thermal expansion of the material of the reinforcing member 23 and the material of the shell 211 to the coefficient of thermal expansion of the material with the smaller coefficient of thermal expansion is 0-50%.

[0226] In this embodiment, by setting the absolute value of the difference between the melting point of the material of the reinforcing member 23 and the melting point of the material of the shell 211 to be less than or equal to 400°C, the melting points of the reinforcing member 23 and the shell 211 are relatively close or even the same, thereby reducing the melting temperature difference between the reinforcing member 23 and the shell 211 during welding. On the one hand, this reduces the welding difficulty between the reinforcing member 23 and the shell 211, thereby reducing the manufacturing difficulty of the battery cell 20. On the other hand, it reduces the occurrence of phenomena such as incomplete welding or welding cracks between the reinforcing member 23 and the shell 211, which is beneficial to improving the welding quality between the reinforcing member 23 and the shell 211.

[0227] In some embodiments, the material of the housing 211 may include steel, and correspondingly, the material of the reinforcing member 23 may include steel or a nickel-based alloy.

[0228] In this embodiment, by setting the material of the shell 211 to steel and the material of the reinforcing member 23 to steel or nickel-based alloy, the structural strength of the shell 211 is improved and the deformation of the shell 211 during use is reduced, while the melting point difference between the reinforcing member 23 and the shell 211 is reduced, thereby reducing the welding difficulty between the reinforcing member 23 and the shell 211 and improving the welding quality between the reinforcing member 23 and the shell 211.

[0229] In some embodiments, the housing 211 may be made of aluminum, and correspondingly, the reinforcing member 23 may be made of aluminum, aluminum alloy, or magnesium alloy.

[0230] In this embodiment, by setting the material of the shell 211 to aluminum and the material of the reinforcing member 23 to aluminum, aluminum alloy or magnesium alloy, the molding difficulty of the shell 211 is reduced, while the melting point difference between the reinforcing member 23 and the shell 211 is reduced, thereby reducing the welding difficulty between the reinforcing member 23 and the shell 211 and improving the welding quality between the reinforcing member 23 and the shell 211.

[0231] According to some embodiments of this application, see Figure 6 As shown, the outer surface of the reinforcing member 23 is covered with a heat insulation layer (not shown in the figure).

[0232] The heat insulation layer is a coating structure applied to the outer surface of the reinforcing member 23, and the heat insulation layer covers the surface of the area where the reinforcing member 23 is not connected to the housing 211.

[0233] For example, the material of the insulation layer can be ceramic, aerogel, aluminum silicate fiber, polymer composite material or nanomaterial, etc.

[0234] In this embodiment, the outer surface of the reinforcing member 23 is covered with a heat insulation layer, which can provide a certain heat insulation effect between the thermal runaway gas and the reinforcing member 23 when the battery cell 20 experiences thermal runaway, thereby improving the thermal shock resistance of the reinforcing member 23. On the one hand, it can reduce the risk of damage or melting of the reinforcing member 23, which is conducive to improving the stability and reliability of the reinforcing member 23 in use. On the other hand, it eliminates the need to use a high-temperature resistant material for the reinforcing member 23, thereby expanding the range of materials that can be selected for the reinforcing member 23. This allows for the use of reinforcing members 23 made of different materials according to actual needs, which is beneficial to optimizing the weight and manufacturing cost of the battery cell 20.

[0235] In some embodiments, the thermal conductivity of the insulation layer material is λ, which satisfies 0.05W / (m·K)≤λ≤0.9W / (m·K).

[0236] For example, the thermal conductivity of the insulation layer material can be 0.05 W / (m·K), 0.06 W / (m·K), 0.07 W / (m·K), 0.08 W / (m·K), 0.09 W / (m·K), 0.1 W / (m·K), 0.12 W / (m·K), 0.15 W / (m·K), 0.18 W / (m·K), 0.2 W / (m·K), or 0.25 W / (m·K). 0.3W / (m·K), 0.35W / (m·K), 0.4W / (m·K), 0.45W / (m·K), 0.5W / (m·K), 0.55W / (m·K), 0.6W / ( m·K), 0.65W / (m·K), 0.7W / (m·K), 0.75W / (m·K), 0.8W / (m·K), 0.85W / (m·K) or 0.9W / (m·K), etc.

[0237] In this embodiment, on the one hand, setting the thermal conductivity of the insulation layer material to be greater than or equal to 0.05 W / (m·K) can reduce the difficulty of material selection for the insulation layer, thereby reducing the manufacturing difficulty and cost of the insulation layer. On the other hand, setting the thermal conductivity of the insulation layer material to be less than or equal to 0.9 W / (m·K) can make the insulation layer have a better insulation effect, so that when the battery cell 20 experiences thermal runaway, the insulation effect between the thermal runaway gas and the reinforcing member 23 can be further improved, thereby further improving the thermal shock resistance of the reinforcing member 23.

[0238] According to some embodiments of this application, this application also provides a battery device 100, which includes a battery cell 20 of any of the above schemes.

[0239] Among them, see Figure 2 As shown, the battery device 100 may also include a housing 10, in which the battery cells 20 are housed.

[0240] In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, the first housing body 11 and the second housing body 12 covering each other, the first housing body 11 and the second housing body 12 together defining an assembly space for accommodating the battery cell 20.

[0241] Optionally, the second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate-like structure. The first box body 11 covers the open side of the second box body 12 so that the first box body 11 and the second box body 12 together define the assembly space; the first box body 11 and the second box body 12 can also be hollow structures with one side open, and the open side of the first box body 11 covers the open side of the second box body 12.

[0242] Of course, the box 10 formed by the first box body 11 and the second box body 12 can be of various shapes, such as a cylinder or a cuboid. For example, in... Figure 2 In the middle, box 10 has a rectangular structure.

[0243] Optionally, the battery cell 20 disposed within the housing 10 can be one or more. For example, in... Figure 2 In the battery device 100, multiple battery cells 20 are arranged inside the housing 10. The multiple battery cells 20 can be connected in series, parallel, or in a mixed manner. A mixed connection means that the multiple battery cells 20 are connected in both series and parallel. The multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the whole assembly of the multiple battery cells 20 is housed in the housing 10. Of course, the battery device 100 can also be formed by first connecting multiple battery cells 20 in series, parallel, or in a mixed manner to form a battery module, and then connecting multiple battery modules in series, parallel, or in a mixed manner to form a whole assembly, which is also housed in the housing 10.

[0244] The battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar component that connects multiple battery cells 20 to achieve electrical connection between the multiple battery cells 20.

[0245] It should be noted that in some embodiments, the battery device 100 may not have a housing 10. The battery device 100 includes multiple battery cells 20, and the battery device 100 composed of multiple battery cells 20 can be directly mounted onto the electrical device to provide power to the electrical device through the multiple battery cells 20. That is, the housing 10 can be part of the electrical device. Taking a vehicle 1000 as an example, the housing 10 can be part of the chassis structure of the vehicle 1000. For example, a portion of the housing 10 can be at least a part of the floor of the vehicle 1000, or a portion of the housing 10 can be at least a part of the crossbeams and longitudinal beams of the vehicle 1000.

[0246] According to some embodiments of this application, in conjunction with Figure 2 , Figure 3 , Figure 4 and Figure 7As shown, the housing 211 includes two first walls 2113a disposed opposite each other in the second direction Y and two second walls 2113b disposed opposite each other in the third direction Z. One end of each of the first walls 2113a and the second wall 2113b in the first direction X is connected to the first end cap 212, and the area of ​​the outer surface of the first wall 2113a is larger than the area of ​​the outer surface of the second wall 2113b. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other. The battery device 100 includes a plurality of battery cells 20 stacked along the second direction Y, and at least one second wall 2113b is provided with a reinforcing member 23 extending along the second direction Y.

[0247] Among them, the first wall 2113a is the wall with the largest outer surface area among the multiple walls of the side wall 2113, so that the first wall 2113a is also a large area of ​​the outer shell 21. Correspondingly, the multiple battery cells 20 in the battery device 100 are stacked along the thickness direction of the battery cells 20.

[0248] In this embodiment, the sidewall 2113 of the housing 211 has two first walls 2113a arranged opposite each other in the second direction Y and two second walls 2113b arranged opposite each other in the third direction Z. The area of ​​the outer surface of the first wall 2113a is larger than the area of ​​the outer surface of the second wall 2113b, so that the battery cell 20 has a square structure, and the first wall 2113a of the housing 211 is a large area of ​​the outer shell 21. The battery cells 20 of the battery device 100 are arranged in a structure of being stacked along the second direction Y, and a reinforcing member 23 is provided on at least one second wall 2113b of the housing 211. This allows the structural strength of at least one second wall 2113b of the housing 211 to be strengthened by the reinforcing member 23. Thus, after the large area of ​​the multiple battery cells 20 is constrained along the second direction Y, the unconstrained second wall 2113b of the housing 211 of the battery cell 20 can be strengthened to reduce the deformation of the second wall 2113b during use. This reduces the tensile and stress effects of the second wall 2113b on the welding position of the first end cover 212 and the housing 211, thereby reducing the risk of connection failure of the first end cover 212 and the housing 211 during use and improving the reliability of the battery device 100.

[0249] In some embodiments, see Figure 7 As shown, both second walls 2113b are provided with reinforcing members 23 extending along the second direction Y.

[0250] In this embodiment, by providing reinforcing members 23 on both second walls 2113b of the housing 211, the structural strength of both second walls 2113b of the housing 211 is such that both are reinforced by the reinforcing members 23. Thus, after the large area of ​​the multiple battery cells 20 is constrained along the second direction Y, the two unconstrained second walls 2113b of the housing 211 of the battery cells 20 can be reinforced, thereby further reducing the deformation of the housing 211 during use. This further reduces the pulling and stress effects of the housing 211 on the welding position of the first end cap 212 and the housing 211, thereby further reducing the risk of connection failure between the first end cap 212 and the housing 211 during use, which is beneficial to further improve the reliability of the battery device 100.

[0251] According to some embodiments of this application, this application also provides an electrical device, which includes a battery cell 20 of any of the above schemes, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0252] The electrical device can be any of the aforementioned devices or systems that utilize battery cells 20.

[0253] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0254] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: The housing includes a shell and a first end cap, wherein a first opening is formed at one end of the shell in a first direction, and the first end cap is welded to the shell and closes the first opening; Electrode assembly, housed within the housing; as well as A reinforcing member protrudes from the inner circumferential surface of the housing and extends circumferentially along the first end cap, and the reinforcing member is located on the side of the first end cap facing the electrode assembly in the first direction. At least a portion of the first end cap is inserted into the housing through the first opening, and the first end cap has a first outer peripheral surface that abuts against the inner peripheral surface of the housing. In a projection plane perpendicular to the first direction, at least a portion of the orthographic projection of the first outer peripheral surface lies within the orthographic projection of the reinforcement.

2. The battery cell according to claim 1, characterized in that, The housing includes a sidewall extending circumferentially along the first end cap, one end of which encloses the first opening in the first direction and is welded to the first end cap. The sidewall has two first walls arranged opposite each other in a second direction and two second walls arranged opposite each other in a third direction. The area of ​​the outer surface of the first wall is larger than the area of ​​the outer surface of the second wall, and at least one of the second walls is provided with a reinforcing member extending along the second direction. The first direction, the second direction and the third direction are perpendicular to each other.

3. The battery cell according to claim 2, characterized in that, The sidewall has a first end and a second end opposite each other in the circumferential direction of the first end cap, the first end and the second end being welded together to form a solder area extending along the first direction; The solder area is located on at least one of the two second walls, and the second wall having the solder area is provided with the reinforcing member extending in the second direction.

4. The battery cell according to claim 2, characterized in that, At least one of the first walls has a protruding reinforcement extending in the third direction.

5. The battery cell according to claim 1, characterized in that, The reinforcing member is a ring structure extending circumferentially along the first end cap.

6. The battery cell according to any one of claims 1-5, characterized in that, Along the first direction, the minimum distance between the reinforcing member and the first end cap is L1, which satisfies 0mm≤L1≤10mm.

7. The battery cell according to claim 6, characterized in that, Along the first direction, the reinforcing member abuts against the first end cap.

8. The battery cell according to claim 6, characterized in that, The first end cap is provided with a pressure relief component, which is configured to release the internal pressure of the battery cell; In a projection plane perpendicular to the first direction, at least a portion of the orthographic projection of the reinforcement lies within the orthographic projection of the first end cap.

9. The battery cell according to claim 8, characterized in that, The reinforcing member has a first surface facing away from the first end cap in the first direction, and the reinforcing member has a second surface facing away from the inner circumferential surface of the housing. The first surface and the second surface are connected by a guide ramp.

10. The battery cell according to claim 9, characterized in that, The reinforcing member intersects the guide slope at a cross section perpendicular to its extension direction to form an intersection line, which may be a straight line or an arc.

11. The battery cell according to claim 8, characterized in that, The reinforcing member protrudes from the inner circumferential surface of the housing by a dimension D1, which satisfies 0.1mm≤D1≤10mm.

12. The battery cell according to any one of claims 1-5, characterized in that, The electrode assembly includes a main body and an electrode tab protruding from the main body. Along the first direction, the reinforcing member and the main body are arranged at intervals, and the reinforcing member is closer to the first end cap than the main body.

13. The battery cell according to any one of claims 1-5, characterized in that, The electrode assembly includes a main body and tabs protruding from the main body. In a projection plane perpendicular to the first direction, the orthographic projection of the reinforcing member is located outside the orthographic projection of the main body and is arranged at intervals.

14. The battery cell according to any one of claims 1-5, characterized in that, The dimension of the reinforcing member in the first direction is D2, which satisfies 0.1mm≤D2≤10mm.

15. The battery cell according to any one of claims 1-5, characterized in that, The reinforcing member and the housing are separately disposed but connected; or The reinforcing member and the housing are integrally formed.

16. The battery cell according to claim 15, characterized in that, The reinforcing member and the housing are separate components, and the reinforcing member is welded to the housing.

17. The battery cell according to claim 16, characterized in that, The material of the reinforcing member has a melting point of P1, and the material of the shell has a melting point of P2, satisfying that 0≤|P1-P2|≤400℃.

18. The battery cell according to claim 16, characterized in that, The shell is made of steel, and the reinforcing member is made of steel or a nickel-based alloy.

19. The battery cell according to claim 16, characterized in that, The shell is made of aluminum, and the reinforcing member is made of aluminum, aluminum alloy, or magnesium alloy.

20. The battery cell according to any one of claims 1-5, characterized in that, The outer surface of the reinforcing member is covered with a heat insulation layer.

21. The battery cell according to claim 20, characterized in that, The thermal conductivity of the insulation layer material is λ, which satisfies 0.05W / (m·K)≤λ≤0.9W / (m·K).

22. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-21.

23. The battery device according to claim 22, characterized in that, The housing includes two first walls disposed opposite each other in a second direction and two second walls disposed opposite each other in a third direction. One end of each of the first wall and the second wall in the first direction is connected to the first end cap, and the area of ​​the outer surface of the first wall is greater than the area of ​​the outer surface of the second wall. The first direction, the second direction and the third direction are perpendicular to each other. The battery device includes a plurality of battery cells stacked along the second direction, and at least one of the second walls is provided with a reinforcing member extending along the second direction.

24. The battery device according to claim 23, characterized in that, Both second walls are provided with the reinforcing member extending along the second direction.

25. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-21, the battery cell being used to provide electrical energy.

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