Battery cell, battery device, and electric device

Abstract

The present application discloses a battery cell, a battery device, and an electric device. The battery cell comprises a casing, an electrode assembly, an insulating member, and a blocking member. The casing comprises a first wall, the first wall is provided with a first through hole, and the melting point of the first wall is greater than or equal to 1200°C and less than or equal to 2000°C. The blocking member is welded to the first wall, and the blocking member seals the first through hole. A welding mark is formed at a connection region between the blocking member and the first wall, and the welding mark is at least partially exposed on the side of the first wall facing away from the electrode assembly. A first recess and a second recess recessed towards the electrode assembly are formed on the insulating member, the second recess at least partially surrounds the periphery of the first recess, and on the same plane perpendicular to the thickness direction of the first wall, the projection of the first recess at least partially overlaps with the projection of the first through hole, and the projection of the second recess at least partially overlaps with the projection of the welding mark. The technical solution provided by the present application can effectively improve the reliability of battery devices.

Description

Battery cells, battery packs and electrical devices 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] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] In the development of battery technology, how to improve the reliability of battery devices is a technical problem that urgently needs to be solved. Summary of the Invention

[0004] This application provides a battery cell, a battery device, and an electrical device. The technical solution provided by this application can effectively improve the reliability of the battery device.

[0005] This application is achieved through the following technical solution:

[0006] In a first aspect, some embodiments of this application provide a battery cell, which includes a casing, an electrode assembly, an insulating member, and a sealing member. The casing includes a first wall having a first through-hole, and the melting point of the first wall is greater than or equal to 1200°C and less than or equal to 2000°C. The electrode assembly is disposed within the casing. The insulating member is disposed within the casing and located between the first wall and the electrode assembly. The sealing member is welded to the first wall and closes the first through-hole. A solder mark is formed at the connection area between the sealing member and the first wall, and the solder mark is at least partially exposed on the side of the first wall opposite to the electrode assembly. The insulating member has a first groove and a second groove recessed toward the electrode assembly, the second groove being at least partially circumferentially surrounding the first groove. On the same plane perpendicular to the thickness direction of the first wall, the projection of the first groove and the projection of the first through-hole at least partially coincide, and the projection of the second groove and the projection of the solder mark at least partially coincide.

[0007] In the above scheme, by setting a second groove on the outer periphery of the first groove, and the second groove corresponding to the solder mark, the distance between the insulating component and the solder mark can be effectively increased, the heat generated when the sealing component is welded to the first wall can be reduced, the influence of the heat generated on the insulating component can be reduced, and the structural integrity of the insulating component can be guaranteed to a certain extent. Thus, the insulating component can effectively play an insulating role, thereby making the battery cell highly reliable and the battery device highly reliable.

[0008] According to some embodiments of this application, the minimum distance between the solder mark and the outer periphery of the second groove along the radial direction of the first through hole is L, which satisfies 0.3mm≤L≤3.2mm.

[0009] In the above scheme, by limiting the minimum radial distance between the solder mark and the outer periphery of the second groove in the first through hole to no less than 0.3 mm, the impact of heat generated during the welding process of the sealing component and the first wall on the insulating component can be reduced, thereby reducing the risk of structural damage to the insulating component and ensuring higher reliability of the battery cell and battery device. By limiting the minimum radial distance between the solder mark and the outer periphery of the second groove in the first through hole to no more than 3.2 mm, the risk of structural strength damage to the insulating component due to the large size of the second groove, leading to a decrease in insulation performance, can be reduced. It can also reduce the risk of interference with other structural components inside the battery cell caused by the large size of the second groove, thus ensuring the compactness of the internal structure of the battery cell to a certain extent, which is beneficial to improving the volumetric energy density of the battery cell and battery device. Therefore, by limiting the minimum radial distance between the solder mark and the outer periphery of the second groove in the first through hole to no less than 0.3 mm and no more than 3.2 mm, the reliability and volumetric energy density of the battery cell, and consequently the reliability and volumetric energy density of the battery device, can be balanced.

[0010] According to some embodiments of this application, the following condition is met: 0.5mm ≤ L ≤ 3mm.

[0011] In the above solution, by limiting the minimum radial distance between the solder mark and the outer periphery of the second groove in the first through hole to not less than 0.5 mm and not more than 3 mm, the reliability and volumetric energy density of the battery cell can be further balanced, thereby balancing the reliability and volumetric energy density of the battery device.

[0012] According to some embodiments of this application, along the thickness direction of the first wall, the insulating member has a first surface facing the first wall, the second groove is formed on the first surface, and the minimum distance between the first surface and the bottom surface of the second groove is H, satisfying 0.05mm≤H≤0.5mm.

[0013] In the above scheme, by limiting the minimum distance between the first surface and the bottom surface of the second groove to no less than 0.05 mm along the thickness direction of the first wall, the impact of heat generated during the welding process of the sealing component and the first wall on the insulating component can be reduced, thereby reducing the risk of structural damage to the insulating component and ensuring high reliability of the battery cell and battery device. By limiting the minimum distance between the first surface and the bottom surface of the second groove to no more than 0.5 mm, the risk of structural strength damage to the insulating component due to the large size of the second groove, leading to a decrease in insulation performance, can be reduced. Simultaneously, the risk of interference with other structural components inside the battery cell due to the large size of the second groove can also be reduced, thus ensuring the compactness of the internal structure of the battery cell to a certain extent, which is beneficial to improving the volumetric energy density of the battery cell and battery device. Therefore, by limiting the minimum distance between the first surface and the bottom surface of the second groove to no less than 0.05 mm and no more than 0.5 mm, both the reliability and volumetric energy density of the battery cell and, consequently, the reliability and volumetric energy density of the battery device can be balanced.

[0014] According to some embodiments of this application, the following condition is satisfied: 0.1mm ≤ H ≤ 0.3mm.

[0015] In the above solution, by limiting the minimum distance between the first surface and the bottom surface of the second groove in the thickness direction of the first wall to not less than 0.1 mm and not more than 0.3 mm, the reliability and volumetric energy density of the battery cell can be further balanced, thereby balancing the reliability and volumetric energy density of the battery device.

[0016] According to some embodiments of this application, the thickness of the first wall is no greater than 1.5 mm.

[0017] In the above scheme, on the one hand, the thickness of the first wall is set to no more than 1.5mm to meet the requirement of increasing volumetric energy density; on the other hand, because the first wall is relatively thin, the risk of weld penetration between the sealing component and the first wall is relatively high. To address this, by setting a second groove, the risk of structural damage to the insulating component caused by the heat generated during welding can be effectively reduced under the condition that the first wall is relatively thin, so that the insulating component can play an effective insulating role, thereby improving the reliability of the battery cell and thus improving the reliability of the battery device.

[0018] According to some embodiments of this application, the tensile strength of the first wall at a temperature of 25°C is Rm, which satisfies 250MPa≤Rm≤2000MPa.

[0019] In the above scheme, on the one hand, by limiting the range of the room temperature tensile strength Rm of the first wall, and ensuring that this range satisfies 250MPa≤Rm≤2000MPa, the deformation resistance of this part can be high, effectively reducing the impact of external impacts on the internal structural components of the battery cell. Thus, under the condition of meeting the impact resistance requirements, the thickness of the first wall can be reduced, which is conducive to improving the volumetric energy density of the battery cell, and consequently, the volumetric energy of the battery device. On the other hand, with a thinner first wall and a higher melting point, the risk of structural damage to the insulation component due to welding of the sealing component and the first wall increases. To address this, by setting a void groove on the insulation component, the problem of structural damage to the insulation component due to the heat generated by welding can be effectively mitigated, thereby making the battery cell more reliable, and consequently, the battery device more reliable.

[0020] According to some embodiments of this application, the following condition is met: 450MPa≤Rm≤800MPa.

[0021] In the above scheme, on the one hand, limiting the tensile strength Rm of the first wall under room temperature conditions to no less than 450MPa ensures strong resistance to deformation, enabling it to withstand the expansion of the electrode assembly or external impacts, making this part less prone to damage, reducing the risk of shell cracking, and thus improving the structural stability and service life of the battery cell. On the other hand, controlling the tensile strength Rm of the first wall under room temperature conditions to be not too high reduces the difficulty of material selection and processing for this end wall, saving costs and facilitating processing.

[0022] According to some embodiments of this application, the material of the first wall includes one of the following materials: steel, copper alloy, titanium alloy, and nickel alloy.

[0023] In the above scheme, the material of the first wall includes one of steel, copper alloy, titanium alloy and nickel alloy, so that the end wall has greater strength, can meet the strength requirements of the battery cell shell, and is easy to process and has a lower cost.

[0024] According to some embodiments of this application, the material of the first wall includes stainless steel or carbon steel.

[0025] In the above scheme, if the first wall is made of stainless steel, its structural strength is relatively high, which can usually meet the tensile strength Rm requirement under the aforementioned room temperature conditions. Furthermore, stainless steel is not prone to rust, which, compared to other materials, improves the reliability of the joint between the end wall and the shell, reducing the risk of shell cracking. If the first wall is made of carbon steel, its structural strength is high, making it easy to meet the tensile strength Rm requirement under the aforementioned room temperature conditions.

[0026] According to some embodiments of this application, the material of the sealing element is the same as the material of the first wall.

[0027] In the above scheme, the sealing component is made of the same material as the first wall, meaning that the sealing component, like the first wall, can meet the tensile strength Rm requirement under the aforementioned room temperature conditions. This improves the reliability of the joint between the first wall and the sealing component, reducing the risk of the first density component detaching from the first wall. Simultaneously, the fact that the sealing component is made of the same material as the first wall reduces the welding difficulty between the sealing component and the first wall, which is beneficial for improving the manufacturing efficiency of the battery cell.

[0028] According to some embodiments of this application, the solder mark is arranged around the central axis of the first through hole.

[0029] In the above solution, by setting the solder mark to surround the central axis of the first through hole, the connection quality between the sealing component and the first wall can be well achieved, effectively reducing the risk of the sealing component detaching from the first wall, enabling the sealing component to effectively seal the first through hole, reducing the risk of electrolyte leakage, and making the battery cell more reliable, thereby making the battery device more reliable.

[0030] According to some embodiments of this application, the second groove is disposed around the central axis of the first through hole.

[0031] In the above scheme, corresponding to the solder mark, the second groove is also set to surround the central axis of the first through hole, which can effectively avoid the solder mark to reduce the impact of the heat generated during the welding process on the insulating component, thereby ensuring the structural integrity of the insulating component to a certain extent, making the battery cell highly reliable, and thus making the battery device highly reliable.

[0032] According to some embodiments of this application, the insulating member has a first surface facing the first wall, the first groove is formed on the first surface, and the minimum distance between the first surface and the bottom surface of the first groove along the thickness direction of the first wall is h, which satisfies 3mm≤h≤6mm.

[0033] In the above solution, by limiting the minimum distance between the first surface and the bottom surface of the first groove to be no less than 3mm and no more than 6mm, on the one hand, the sealing component can utilize the space where the first groove is located, making the battery cell structure compact; on the other hand, it can reduce the occupancy of the insulating component on the internal space of the battery cell and reduce the impact on the volumetric energy density of the battery cell; furthermore, when the first through hole is used for injecting electrolyte, the first groove can act as a buffer for the electrolyte, reducing the impact of the electrolyte on the internal structural components of the battery cell and improving the electrolyte injection efficiency.

[0034] According to some embodiments of this application, the insulating member includes an insulating body, a peripheral wall, and a bottom wall. One end of the peripheral wall surrounds the edge of the bottom wall, and the other end of the peripheral wall is connected to the insulating body. The peripheral wall and the bottom wall together form the first groove, and at least a portion of the second groove is formed on the side of the peripheral wall facing the first wall.

[0035] In the above scheme, by defining at least a portion of the second groove as being formed on the peripheral wall, the insulating structure can be made compact, resulting in a high volumetric energy density of the battery cell.

[0036] According to some embodiments of this application, the peripheral wall is formed with a second through hole.

[0037] In the above solution, by forming a second through hole on the peripheral wall, the electrolyte does not directly impact the electrode assembly when the first through hole is used for electrolyte injection. This reduces the risk of damage to the electrode assembly structure caused by the impact of the electrolyte during injection, resulting in high reliability of the battery cell and improving the reliability of the battery device.

[0038] According to some embodiments of this application, the projection of the solder mark and the projection of the peripheral wall at least partially overlap on the same plane perpendicular to the thickness direction of the first wall.

[0039] In the above scheme, the solder mark is at least partially aligned with the peripheral wall. The peripheral wall, which has a larger dimension along the thickness direction of the first wall, resists the high temperature generated during welding, thereby reducing the risk of insulation failure due to high temperature melting of the insulating component. This ensures the reliability of the battery cell to a certain extent and is conducive to improving the reliability of the battery device.

[0040] According to some embodiments of this application, along the thickness direction of the first wall, the first wall has a second surface opposite to the electrode assembly, the second surface is formed with a third groove, and the first through hole penetrates the bottom wall of the third groove; a portion of the sealing member is located within the third groove.

[0041] In the above solution, by setting a third groove on the side of the first wall away from the battery assembly, it can serve a positioning function, reducing the difficulty of assembling the sealing component on the first wall, thereby improving the manufacturing efficiency of the battery cell; on the other hand, it can accommodate the sealing component, reducing the impact of the sealing component on the size of the battery cell, and thus improving the volumetric energy density of the battery cell.

[0042] According to some embodiments of this application, along the thickness direction of the first wall, the distance between the second surface and the bottom surface of the third groove is S, which satisfies 0.8mm≤S≤1.5mm.

[0043] In the above scheme, by limiting the distance between the second surface and the bottom surface of the third groove to not less than 0.8mm, the third groove can play the role of positioning and accommodating the sealing component, thereby improving the manufacturing efficiency of the battery cell. By limiting the distance between the second surface and the bottom surface of the third groove to not more than 1.5mm, the forming difficulty of the third groove is reduced, thereby improving the manufacturing efficiency of the battery cell and the manufacturing efficiency of the battery device.

[0044] According to some embodiments of this application, the sealing member includes a main body and an edge portion, at least a portion of the edge portion is circumferentially disposed around the outer periphery of the main body portion, at least a portion of the main body portion is located in the third groove, the edge portion overlaps the second surface, and the solder mark penetrates the edge portion.

[0045] In the above solution, by overlapping the edge with the outer side of the first wall (i.e., the second surface) and welding the edge and the first wall with through welding, the problem that some materials with a melting point of 1200℃ or higher have high hardness and are difficult to stamp grooves on their surface, and the sealing parts cannot be fully set in the third groove, thus making it impossible to implement the flush welding process.

[0046] According to some embodiments of this application, on the same plane perpendicular to the thickness direction of the first wall, the minimum distance between the projection of the solder mark and the projection of the bottom wall of the third groove is j, which satisfies 1mm≤j≤3mm.

[0047] In the above scheme, the solder mark is located at the edge and the overlapping part of the second surface, so that there is a gap between the solder mark and the third groove. By limiting the distance between the solder mark and the bottom wall of the third groove to not less than 1mm, the risk of poor welding between the sealing component and the first wall can be reduced. By limiting the distance between the solder mark and the bottom wall of the third groove to not more than 3mm, the risk of interference between the solder mark and other structural components located outside the first wall can be reduced, making the battery device structure compact and conducive to improving the volumetric energy density of the battery device.

[0048] According to some embodiments of this application, a limiting portion is provided on the side of the main body facing the first wall along the thickness direction of the first wall. The limiting portion is used to contact the groove side of the third groove to limit the radial displacement of the sealing member along the first through hole.

[0049] In the above solution, by setting a limiting part on the side of the main body facing the first wall, the radial movement of the sealing part along the first through hole can be restricted, which is conducive to the positioning and assembly of the sealing part on the first wall, thereby reducing the precision requirements for welding the sealing part to the first wall, which is conducive to improving the manufacturing efficiency of the battery cell, and thus making the battery device have a higher manufacturing efficiency.

[0050] According to some embodiments of this application, along the thickness direction of the first wall, a recess is formed on the side of the main body away from the first wall, and the position of the recess corresponds to the position of the limiting part.

[0051] In the above solution, by providing a recessed portion on the side of the main body away from the first wall and corresponding to the limiting portion, on the one hand, the material cost of the sealing component can be saved, which is conducive to reducing the manufacturing cost of the battery cell; on the other hand, the location of the recessed portion and the limiting portion can improve the elastic performance of the sealing component, thereby reducing the risk of cracking due to stretching when the sealing component is welded to the first wall, or improving the sealing component's ability to withstand external impacts, reducing the risk of structural damage to the sealing component due to external impacts, so that the battery cell has higher reliability, and thus the battery device has higher reliability.

[0052] According to some embodiments of this application, the limiting portion is arranged around the central axis of the sealing member.

[0053] In the above solution, by setting the limiting part to surround the central axis of the sealing part, the sealing part can be constrained relative to the first through hole in the circumferential direction, thereby stabilizing the assembly relationship between the sealing part and the first wall, reducing the difficulty of welding the two, and improving the manufacturing efficiency of battery cells.

[0054] According to some embodiments of this application, the battery cell further includes a seal disposed in the first through hole.

[0055] In the above solution, by setting a seal to block the first through hole, the risk of electrolyte leakage can be effectively reduced, which is conducive to improving the reliability of the battery cell.

[0056] Secondly, some embodiments of this application also provide a battery device, including the battery cell provided in the first aspect.

[0057] Thirdly, some embodiments of this application also provide an electrical device, including a battery cell provided in the first aspect and / or a battery device provided in the second aspect, wherein the battery cell is used to provide electrical energy.

[0058] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application.

[0059] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0060] 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.

[0061] Figure 1 is a schematic diagram of the vehicle structure in some embodiments of this application;

[0062] Figure 2 is an exploded perspective view of the battery device in some embodiments of this application;

[0063] Figure 3 is a perspective view of a single battery cell in some embodiments of this application;

[0064] Figure 4 is an exploded perspective view of a battery cell in some embodiments of this application;

[0065] Figure 5 is a schematic diagram of the internal structure of a single battery cell in some embodiments of this application;

[0066] Figure 6 is an enlarged view of point A in Figure 5;

[0067] Figure 7 is a schematic diagram of the insulating element in some embodiments of this application;

[0068] Figure 8 is a schematic diagram of a partial structure of the insulating element in some embodiments of this application;

[0069] Figure 9 is a partial structural schematic diagram of the sealing element, the first wall, and the insulating element in some other embodiments of this application;

[0070] Figure 10 is a schematic diagram of the first wall and the insulating element in some embodiments of this application;

[0071] Figure 11 is a schematic diagram of the sealing element in some embodiments of this application.

[0072] Icons: 1000 - Vehicle; 100 - Battery Unit; 200 - Controller; 300 - Motor; 20 - Housing; 21 - First Housing Body; 22 - Second Housing Body; 10 - Battery Cell; 11 - Housing; 110 - Shell; 111 - First Wall; 112 - First Through Hole; 113 - Second Surface; 1130 - Third Groove; 12 - Electrode Assembly; 120 - Tab; 121 - Adapter; 13 - Insulator; 130 - First Surface; 13 0a - First groove; 131 - Second groove; 134 - Terminal hole; 135 - Pressure relief hole; 136 - Insulating body; 137 - Peripheral wall; 138 - Bottom wall; 14 - Sealing element; 140 - Welding mark; 141 - Main body; 142 - Edge; 143 - Limiting part; 144 - Recessed part; 15 - Sealing element; 16 - Electrode terminal; 17 - Pressure relief mechanism; z - Thickness direction of the first wall; x - Radial direction of the first through hole; s - Central axis of the first through hole. Detailed Implementation

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] In this application, "multiple" means two or more (including two).

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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, nickel, 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.).

[0086] 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 / 3 O2 (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 NCM1), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM6), 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.

[0087] 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.

[0088] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0089] 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 electrode, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, 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 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.).

[0090] 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.

[0091] 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.

[0092] 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.

[0093] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0094] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0102] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0103] 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.

[0104] 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.

[0105] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0106] In some implementations, the electrode assembly has a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0107] In some implementations, the electrode assembly has a stacked structure.

[0108] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0109] 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.

[0110] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0111] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0112] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0113] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] The battery apparatus 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 connected in series, parallel, or mixed connections via a busbar.

[0118] 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 together to form a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0119] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0120] 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.

[0121] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. The energy storage device includes energy storage containers, energy storage cabinets, etc. In some embodiments, one or more energy storage devices may constitute at least part of an energy storage system.

[0126] 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, and discharge capacity. Furthermore, the reliability of the battery device must also be taken into account.

[0127] Generally, a battery cell includes a casing, an electrode assembly, an insulating component, and a sealing component, with the electrode assembly disposed within the casing. The casing includes a first wall, and the insulating component is disposed between the first wall and the electrode assembly. The first wall has a first through-hole. The sealing component is welded to the first wall and seals the first through-hole. Exemplarily, the first through-hole can be used for electrolyte injection, internal pressure relief of the battery cell, etc. Optionally, the first through-hole can be an injection port. Optionally, the first through-hole can be a pressure relief port.

[0128] In related technologies, by selecting materials with good material properties as the outer shell, the wall thickness of the outer shell can be made thinner, thereby increasing the volumetric energy density of the battery cell. However, such materials have a high melting point, and the heat generated during the welding process between the sealing component and the first wall can cause the insulating component to melt, damaging the structure of the insulating component and affecting its insulation performance, thus affecting the reliability of the battery cell and the battery device.

[0129] In view of this, to improve the problem of heat generated during the welding process of the sealing component and the first wall causing damage to the insulation structure and affecting the reliability of the battery cell and battery device, some embodiments of this application provide a battery cell, which includes a shell, an electrode assembly, an insulating component, and a sealing component. The shell includes a first wall with a first through hole, and the melting point of the first wall is greater than or equal to 1200°C and less than or equal to 2000°C. The electrode assembly is disposed within the shell. The insulating component is disposed within the shell and located between the first wall and the electrode assembly. The sealing component is welded to the first wall and closes the first through hole. A weld mark is formed at the connection area between the sealing component and the first wall, and the weld mark is at least partially exposed on the side of the first wall opposite to the electrode assembly. The insulating component has a first groove and a second groove recessed towards the electrode assembly, and the second groove is at least partially circumferentially disposed around the outer periphery of the first groove. On the same plane perpendicular to the thickness direction of the first wall, the projection of the first groove and the projection of the first through hole at least partially coincide, and the projection of the second groove and the projection of the weld mark at least partially coincide.

[0130] In the above scheme, by setting a second groove on the outer periphery of the first groove, and the second groove corresponding to the solder mark, the distance between the insulating component and the solder mark can be effectively increased, the heat generated when the sealing component is welded to the first wall can be reduced, the influence of the heat generated on the insulating component can be reduced, and the structural integrity of the insulating component can be guaranteed to a certain extent. Thus, the insulating component can effectively play an insulating role, thereby making the battery cell highly reliable and the battery device highly reliable.

[0131] The battery cells disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft.

[0132] 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.

[0133] 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.

[0134] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 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 power the vehicle 1000; for example, it can serve as the vehicle's operating power source or general power source. 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.

[0135] 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.

[0136] Please refer to Figure 2, which is an exploded perspective view of the battery device 100 in some embodiments of this application. The battery device 100 includes a housing 20 and battery cells 10, the battery cells 10 being housed within the housing 20.

[0137] The housing 20 provides assembly space for the battery cell 10, and can adopt various structures. In some embodiments, the housing 20 may include a first housing body 21 and a second housing body 22, which overlap each other, and together define an assembly space for accommodating the battery cell 10. The second housing body 22 may be a hollow structure open at one end, and the first housing body 21 may be a plate-like structure, with the first housing body 21 covering the open side of the second housing body 22 so that the first housing body 21 and the second housing body 22 together define the assembly space; alternatively, the first housing body 21 and the second housing body 22 may both be hollow structures open on one side, with the open side of the first housing body 21 covering the open side of the second housing body 22.

[0138] Of course, the box 20 formed by the first box body 21 and the second box body 22 can be of various shapes, such as a cylinder, a cuboid, or a cube. For example, in Figure 2, the shape of the box 20 is a cuboid.

[0139] In the battery device 100, there can be one or more battery cells 10 disposed within the housing 20. When there are multiple battery cells 10 disposed within the housing 20, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 10 are connected in both series and parallel configurations. Multiple battery cells 10 can be directly connected in series, in parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 10 is housed within the housing 20. Alternatively, the battery device 100 can also be composed of multiple battery cells 10 first connected in series, in parallel, or in a mixed configuration to form a battery module, and then the 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 20.

[0140] 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 10 to achieve electrical connection between the multiple battery cells 10.

[0141] For example, the housing 20 is provided with a plurality of battery cell assemblies, each battery cell assembly including a plurality of battery cells 10 stacked on top of each other, and the plurality of battery cells 10 are connected in series with each other through a busbar. In some embodiments, the plurality of battery cell assemblies can be connected in series with each other through a busbar.

[0142] Each battery cell 10 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 10 can be in the form of a cuboid, cylinder, prism, or other shapes. For example, in Figure 3, the battery cell 10 has a cuboid structure.

[0143] This application provides a battery cell 10 in some embodiments. Please refer to Figures 3-7. Figure 3 is a perspective view of the battery cell 10 in some embodiments of this application. Figure 4 is an exploded perspective view of the battery cell 10 in some embodiments of this application. Figure 5 is a schematic diagram of the internal structure of the battery cell 10 in some embodiments of this application. Figure 6 is an enlarged view of point A in Figure 5. Figure 7 is a schematic diagram of the insulating member 13 in some embodiments of this application.

[0144] The battery cell 10 includes a housing 11, an electrode assembly 12, an insulator 13, and a sealing member 14. The housing 11 includes a first wall 111 having a first through-hole 112. The melting point of the first wall 111 is greater than or equal to 1200°C and less than or equal to 2000°C. The electrode assembly 12 is disposed within the housing 11. The insulator 13 is disposed within the housing 11 and located between the first wall 111 and the electrode assembly 12. The sealing member 14 is welded to the first wall 111 and closes the first through-hole 112. The connection area between the sealing member 14 and the first wall 111 forms a solder mark 140, which is at least partially exposed on the side of the first wall 111 opposite to the electrode assembly 12. The insulating member 13 has a first groove 130a and a second groove 131 recessed toward the electrode assembly 12. The second groove 131 is at least partially circumferentially disposed around the outer periphery of the first groove 130a. On the same plane perpendicular to the thickness direction of the first wall 111, the projection of the first groove 130a and the projection of the first through hole 112 at least partially coincide, and the projection of the second groove 131 and the projection of the solder mark 140 at least partially coincide.

[0145] In some embodiments, the outer casing 11 can be used to contain an electrolyte, such as an electrolyte solution. The outer casing 11 can have various structural forms, such as a square shell structure, a cylindrical shell structure, etc.

[0146] In some embodiments, referring to FIG3, the housing 11 includes a housing 110 and an end wall. The housing 110 has an internal cavity with an opening, meaning the housing 110 is a hollow structure with one end open. The end wall covers the opening of the housing 110 and forms a sealed connection to create a sealed space for accommodating the electrode assembly 12 and the electrolyte (e.g., electrolyte solution). In some embodiments, the connection between the end wall and the housing 110 is varied, including but not limited to bonding, welding, riveting, or threaded connections.

[0147] Optionally, there are two end walls, and the two opposite ends of the housing 110 are open, that is, they have two opposite openings. One opening can be closed by one end wall, and the other opening can be closed by the other end wall.

[0148] The housing 110 can have various shapes, such as a cylinder or a cuboid. The shape of the housing 110 can be determined according to the specific shape of the electrode assembly 12. For example, if the electrode assembly 12 is a cylindrical structure, then the housing 110 can be a cylindrical structure; if the electrode assembly 12 is a cuboid structure, then the housing 110 can be a cuboid structure. Of course, the end walls can also have various shapes, which can correspond to the shape of the housing 110. For example, please refer to Figures 3 and 4, where the housing 110 is a cuboid structure, and correspondingly, the end walls are rectangular structures.

[0149] In some embodiments of this application, the housing 11 includes a first wall 111. Optionally, the first wall 111 may be an end wall, or the first wall 111 may be a wall portion at other locations of the housing 11.

[0150] Optionally, the thickness direction z of the first wall can be the height direction of the battery cell 10. In some other embodiments, the thickness direction z of the first wall can be the width direction or the thickness direction of the battery cell 10.

[0151] Some embodiments of this application are illustrated using the first wall 111 as an end wall as an example.

[0152] The melting point of the first wall 111 is greater than or equal to 1200°C and less than or equal to 2000°C. For example, the melting point of the first wall 111 can be 1200°C, 1210°C, 1220°C, 1230°C...1650°C, 1660°C, 1670°C, 1680°C, 1690°C, 1700°C, 1800°C, 1900°C, 2000°C or any value between two adjacent values.

[0153] In some embodiments, the melting point of the first wall 111 may be greater than or equal to 1200°C and less than or equal to 1510°C.

[0154] In some embodiments, the melting point of the first wall 111 may be greater than or equal to 1650°C and less than or equal to 1670°C.

[0155] For example, the material of the first wall 111 includes, but is not limited to, steel, copper alloy, titanium alloy and nickel alloy.

[0156] Optionally, the material of the first wall 111 includes a copper alloy with a melting point greater than or equal to 1200°C, such as a copper-nickel alloy. Optionally, the material of the first wall 111 includes stainless steel or carbon steel. Optionally, the material of the first wall 111 may include austenitic stainless steel, martensitic stainless steel, or ferritic stainless steel.

[0157] In some embodiments, the melting point of other parts of the housing 11 may also be greater than or equal to 1200°C and less than or equal to 2000°C. Optionally, the material of other parts of the housing 11 may be the same as the material of the first wall 111. For example, the housing 11 may be a steel shell, and the materials of other parts of the housing 11 and the first wall 111 may both be stainless steel.

[0158] It should be noted that the "melting point" mentioned in some embodiments of this application can be understood as the temperature at which a solid changes its state from solid to liquid (melts). For example, the material of the first wall 111 is a metallic material, and its melting point can be understood as the critical temperature at which the metal changes from a solid to a liquid state under specific pressure. At this temperature, the solid and liquid phases of the metal are in equilibrium, and the temperature will not rise further with continued heating until complete melting, after which the temperature will rise again.

[0159] In some embodiments of this application, the method for measuring the melting point of the first wall 111 includes, but is not limited to, traditional methods (such as the melting point test tube and furnace method or the thermal expansion method), modern instrumental analysis methods (such as differential thermal analyzer, differential scanning calorimeter, or spectroscopic analysis methods).

[0160] The electrode assembly 12 is a component in the battery cell 10 where electrochemical reactions occur. The structure of the electrode assembly 12 can be various. For example, the electrode assembly 12 includes an electrode and a separator. For example, the electrode assembly 12 can be a wound structure formed by winding a positive electrode, a separator and a negative electrode, or a stacked structure formed by arranging a positive electrode, a separator and a negative electrode in layers.

[0161] Optionally, 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.

[0162] The electrode assembly 12 has tabs 120 for inputting or outputting the positive or negative electrode of the electrode assembly 12. The tabs 120 are connected to the electrode terminals 16 via adapters 121 to achieve an electrical connection between the electrode assembly 12 and the electrode terminals 16. In some embodiments, the tabs 120 are located at one end of the electrode assembly 12 near the first wall 111 along the thickness direction z of the first wall; or, along the thickness direction z of the first wall, the tabs 120 are disposed on the side of the electrode assembly 12.

[0163] Optionally, the electrode assembly 12 housed within the housing 11 can be one or more. For example, in FIG4, the housing 11 of the battery cell 10 is provided with two electrode assemblies 12, which are stacked along their thickness direction. That is, the two electrode assemblies 12 are stacked along the thickness direction of the battery cell 10. Of course, in other embodiments, the electrode assembly 12 housed within the housing 11 can be one, three, four, five, six, seven, or eight, etc.

[0164] In some embodiments, the first wall 111 is provided with an electrode terminal 16, which is electrically connected to the tab 120 of the electrode assembly 12. The electrode terminal 16 serves to output or input electrical energy of the battery cell 10. One end of the electrode terminal 16 is used to connect to the tab 120 of the electrode assembly 12, and the other end is used to connect to the busbar component to realize the input or output of electrical energy of the battery cell 10.

[0165] For example, the electrode terminal 16 can be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. Of course, in some embodiments, the electrode terminal 16 can also be a composite material, that is, the electrode terminal 16 is formed by connecting two different metal materials, such as by hot pressing or cold pressing.

[0166] The assembly relationship between the electrode terminal 16 and the first wall 111 is varied, including riveting, bonding, snap-fitting, or connection through other structural components.

[0167] Optionally, the electrode terminal 16 can be directly connected to the tab 120 of the electrode assembly 12, such as by welding or abutting, or it can be indirectly connected to the tab 120 of the electrode assembly 12 through other components. Similarly, the connection structure between the electrode terminal 16 and the bus component can also be various, such as welding, abutting, or snap-fitting.

[0168] In some embodiments, as shown in FIG4, the battery cell 10 may further include an adapter 121 disposed within the housing 11. The adapter 121 connects the electrode terminal 16 and the tab 120 of the electrode assembly 12 to realize the electrical connection between the electrode assembly 12 and the electrode terminal 16.

[0169] The insulating member 13 is a structural component disposed between the first wall 111 and the electrode assembly 12. The insulating member 13 can be made of an insulating material, such as silicone rubber, styrene-butadiene rubber, or other insulating materials. In some embodiments, the insulating member 13 can be a lower plastic disposed on the inner side of the first wall 111. The connection relationship between the insulating member 13 and the first wall 111 is diverse, including but not limited to snap-fit, adhesive, threaded connection, or other connection relationships.

[0170] Optionally, the insulating member 13 has a terminal hole 134 through which the power supply terminal 16 passes so that the electrode terminal 16 is electrically connected to the tab 120.

[0171] The first wall 111 has an injection hole for injecting electrolyte, such as a liquid electrolyte, into the battery cell 10. Optionally, the injection hole can have various shapes, including but not limited to circular, square, triangular, or other shapes.

[0172] Optionally, referring to Figures 4 and 7, the battery cell 10 may further include a pressure relief mechanism 17, which is disposed on the first wall 111. The pressure relief mechanism 17 is used to release the internal pressure of the battery cell 10 when the internal pressure or temperature reaches a predetermined value. Optionally, the first wall 111 may be provided with a pressure relief hole, which is closed by the pressure relief mechanism 17.

[0173] The first through hole 112 is a through-hole structure formed on the first wall 111, penetrating the first wall 111. The first through hole 112 allows material to enter the inner side of the first wall 111 from the outside, or allows material to exit from the inner side of the first wall 111 to the outer side. Optionally, the first through hole 112 can be an injection hole for injecting electrolyte into the interior of the battery cell 10.

[0174] Optionally, the first through hole 112 can be a pressure relief hole to allow the discharge of high-temperature and high-pressure substances inside the battery cell.

[0175] The sealing member 14 is a structural member used to close the first through hole 112. Exemplarily, along the thickness direction z of the first wall, the projected area of ​​the sealing member 14 is greater than or equal to the projected area of ​​the first through hole 112, so as to be able to close the first through hole 112.

[0176] Optionally, when the first through hole 112 is a liquid injection hole, the sealing element 14 can be a sealing pin.

[0177] Optionally, when the first through hole 112 is a pressure relief hole, the sealing element 14 can be a pressure relief mechanism 17.

[0178] In some embodiments of this application, the first through hole 112 is used as an example for liquid injection.

[0179] In some embodiments, after injection, the first through hole 112 can be sealed by the sealing member 14. Exemplarily, the sealing member 14 is a metal structure, welded to the first wall 111 to seal the first through hole 112. Optionally, in some embodiments, at the injection port, the first through hole 112 is first sealed by a sealing member 15, for example, by inserting the sealing member 15 into the first through hole 112, and then welding the sealing member 14 to the outside of the first wall 111 to achieve the closure of the first through hole 112, so that the sealing member 15 effectively seals the first through hole 112. Exemplarily, the sealing member 15 is a rubber nail inserted into the first through hole 112, and the sealing member 14 is a metal sealing nail welded to the first wall 111.

[0180] In some embodiments, "weld mark 140" can be understood as an imprint formed by welding the sealing member 14 and the first wall 111 together. Optionally, the welding may include ultrasonic welding, laser welding, or other welding methods.

[0181] "The weld mark 140 is at least partially exposed on the side of the first wall away from the electrode assembly" can be understood as at least part of the weld mark 140 being visible when viewed from the outside of the first wall 111; it can also be understood as the sealing member 14 and the first wall 111 being welded from the outside to the inside of the first wall 111, and the weld mark 140 formed by the welding is at least partially located on the outer surface of the battery cell 10.

[0182] In some embodiments, the location of the solder mark 140 is varied. Optionally, a third groove 1130 is formed on the outer surface of the first wall 111, and the solder mark 140 may be formed between the groove sidewall of the third groove 1130 and the outer peripheral surface of the sealing member 14. Optionally, the sealing member 14 overlaps the outer side of the first wall 111, and the solder mark 140 may be formed at the overlap position and penetrate into the first wall 111.

[0183] In some embodiments, the solder mark 140 takes various forms, including but not limited to dotted, ring-shaped, intermittent ring-shaped (multi-segment arc-shaped solder mark 140 or multi-segment line-shaped solder mark 140 arranged around the center of the sealing member 14) or other forms.

[0184] The first groove 130a is a groove-shaped structure formed on the side of the insulating member 13 facing the first wall 111. A gap exists between the bottom wall of the first groove 130a and the first wall 111 to form a cavity. The first groove 130a and the first through hole 112 are at least partially opposite each other to accommodate substances injected through the first through hole 112 or substances discharged into the first through hole 112. Exemplarily, the cavity formed by the first groove 130a can accommodate electrolyte; further exemplarily, the cavity formed by the first groove 130a can accommodate high-temperature, high-pressure substances inside a battery cell.

[0185] Referring to Figures 6 and 7, the first surface 130 is the surface of the insulating member 13 facing the first wall 111. In some embodiments, the first surface 130 may be in contact with the inner surface of the first wall 111. The second groove 131 is a groove-shaped structure formed on the first surface 130, for example, the bottom surface of the second groove 131 is further away from the first wall 111 than the first surface 130.

[0186] The phrase “the second groove 131 is at least partially surrounding the outer periphery of the first groove 130a” can be understood as the second groove 131 being located on the outer periphery of the first groove 130a. For example, the second groove 131 surrounds the outer periphery of the first groove 130a; or for example, the second groove 131 is located on the outer periphery of the first groove 130a and does not completely surround the first groove 130a.

[0187] In some embodiments, the second groove 131 has various structural forms. Optionally, the second groove 131 can be an annular structure, which is arranged around the first groove 130a. Optionally, the second groove 131 can be an intermittent annular structure, such as multiple arc-shaped or line-segment-shaped groove structures arranged at intervals around the outer periphery of the first groove 130a.

[0188] The phrase "the projection of the second groove and the projection of the solder mark at least partially overlap" can be understood as follows: a second groove 131 is formed at the location of the insulating member 13 corresponding to the location of the solder mark 140, such that there is a gap between this portion and the first wall 111. Alternatively, it can be understood as a gap between the solder mark 140 and the insulating member 13 along the thickness direction z of the first wall. Or, it can be understood as a gap between the solder mark 140 and the insulating member 13 along the thickness direction z of the first wall, and also a gap between the solder mark 140 and the insulating member 13 along the radial direction x of the first through hole.

[0189] In the above solution, by providing a second groove 131 on the side of the insulating component 13 facing the first wall 111 and corresponding to the solder mark 140, a certain distance can be maintained between the part of the insulating component 13 corresponding to the solder mark 140 and the welding part. This reduces the impact of the heat generated during the welding process of the sealing component 14 and the first wall 111 on the insulating component 13, and to a certain extent ensures the structural integrity of the insulating component 13. This allows the insulating component 13 to effectively perform its insulating function, thereby increasing the reliability of the battery cell 10 and the battery device 100.

[0190] According to some embodiments of this application, the minimum distance between the solder mark 140 and the outer periphery of the second groove 131 along the radial x of the first through hole is L, which satisfies 0.3mm≤L≤3.2mm.

[0191] The radial direction x of the first through hole can be perpendicular to the thickness direction z of the first wall. Referring to Figure 6, the minimum distance L between the solder mark 140 and the outer periphery of the second groove 131 along the radial direction x of the first through hole can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm...2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm or any value between two values.

[0192] Optionally, the method for measuring the outer periphery of the solder mark 140 and the second groove 131 along the radial x of the first through hole may include radiographic measurement. Optionally, the method for measuring the outer periphery of the solder mark 140 and the second groove 131 along the radial x of the first through hole includes cutting open the battery cell 10 along the axial direction of the first through hole 112 and measuring the minimum distance between the outer periphery of the solder mark 140 and the second groove 131 by direct measurement.

[0193] In the above scheme, by limiting the minimum distance between the outer periphery of the solder mark 140 and the second groove 131 in the radial x direction of the first through hole to no less than 0.3 mm, the impact of the heat generated during the welding process of the sealing component 14 and the first wall 111 on the insulating component 13 can be reduced, thereby reducing the risk of structural damage to the insulating component 13 and making the battery cell 10 and battery device 100 have higher reliability. By limiting the minimum distance between the outer periphery of the solder mark 140 and the second groove 131 in the radial x direction of the first through hole to no more than 3.2 mm, the risk of the insulating component 13's own structural strength being damaged due to the large size of the second groove 131, resulting in a decrease in insulation performance, can be reduced. At the same time, the risk of interference with other structural components inside the battery cell 10 due to the large size of the second groove 131 can also be reduced, thereby ensuring the compactness of the internal structure of the battery cell 10 to a certain extent, which is conducive to improving the volumetric energy density of the battery cell 10 and battery device 100. In this regard, by limiting the minimum distance between the solder mark 140 and the outer periphery of the second groove 131 in the radial x of the first through hole to not less than 0.3 mm and not more than 3.2 mm, the reliability and volumetric energy density of the battery cell 10 can be balanced, thereby balancing the reliability and volumetric energy density of the battery device 100.

[0194] According to some embodiments of this application, the following condition is met: 0.5mm ≤ L ≤ 3mm.

[0195] Along the radial x of the first through hole, the minimum distance L between the solder mark 140 and the outer periphery of the second groove 131 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm...2.8mm, 2.9mm, 3mm or any value between the two.

[0196] In the above solution, by limiting the minimum distance between the solder mark 140 and the outer periphery of the second groove 131 in the radial x of the first through hole to not less than 0.5 mm and not more than 3 mm, the reliability and volumetric energy density of the battery cell 10 can be further balanced, thereby balancing the reliability and volumetric energy density of the battery device 100.

[0197] According to some embodiments of this application, the insulating member 13 has a first surface 130 facing the first wall 111, and a second groove 131 is formed on the first surface 130. Along the thickness direction z of the first wall, the minimum distance between the first surface 130 and the bottom surface of the second groove 131 is H, which satisfies 0.05mm≤H≤0.5mm.

[0198] The "minimum distance between the first surface 130 and the bottom surface of the second groove 131" can be understood as the minimum groove depth of the second groove 131. For example, with the bottom surface of the second groove 131 and the solder mark 140 as the relative positions, along the thickness direction z of the first wall, the minimum distance between the solder mark 140 and the bottom surface of the second groove 131 is greater than or equal to H. The value of H can be 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm or any value between two adjacent values.

[0199] In the above scheme, by limiting the minimum distance between the first surface 130 and the bottom surface of the second groove 131 to no less than 0.05mm along the thickness direction z of the first wall, the impact of the heat generated during the welding process of the sealing component 14 and the first wall 111 on the insulating component 13 can be reduced, thereby reducing the risk of structural damage to the insulating component 13 and making the battery cell 10 and battery device 100 have higher reliability. By limiting the minimum distance between the first surface 130 and the bottom surface of the second groove 131 to no more than 0.5mm, the risk of the insulating component 13's own structural strength being damaged due to the large size of the second groove 131, resulting in a decrease in insulation performance, can be reduced. At the same time, the risk of interference with other structural components inside the battery cell 10 caused by the large size of the second groove 131 can also be reduced, thereby ensuring the compactness of the internal structure of the battery cell 10 to a certain extent, which is conducive to improving the volumetric energy density of the battery cell 10 and battery device 100. In this regard, by limiting the minimum distance between the first surface 130 and the bottom surface of the second groove 131 to not less than 0.05 mm and not more than 0.5 mm, the reliability and volumetric energy density of the battery cell 10 can be balanced, thereby balancing the reliability and volumetric energy density of the battery device 100.

[0200] According to some embodiments of this application, the following condition is satisfied: 0.1mm ≤ H ≤ 0.3mm.

[0201] Optionally, along the thickness direction z of the first wall, the minimum distance between the solder mark 140 and the bottom surface of the second groove 131 is greater than or equal to H, where H can be 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm or any value between two adjacent values.

[0202] In the above scheme, by limiting the minimum distance between the first surface 130 and the bottom surface of the second groove 131 in the thickness direction z of the first wall to not less than 0.1 mm and not more than 0.3 mm, the reliability and volumetric energy density of the battery cell 10 can be further balanced, thereby balancing the reliability and volumetric energy density of the battery device 100.

[0203] According to some embodiments of this application, the thickness of the first wall 111 is no greater than 1.5 mm.

[0204] In some embodiments, the thickness of the first wall 111 can be 1.5mm, 1.4mm, 1.3mm, 1.2mm, 1.1mm, 1mm, a smaller value, or any value between two adjacent values.

[0205] In the above scheme, on the one hand, the thickness of the first wall 111 is set to no more than 1.5mm to meet the requirement of increasing volumetric energy density; on the other hand, because the first wall 111 is relatively thin, the risk of weld penetration between the sealing component 14 and the first wall 111 is relatively high. In this regard, by setting the second groove 131, the risk of structural damage to the insulating component 13 caused by the heat generated during the welding process can be effectively reduced under the condition that the first wall 111 is relatively thin, so that the insulating component 13 can play an effective insulating role, thereby improving the reliability of the battery cell 10 and thus improving the reliability of the battery device 100.

[0206] According to some embodiments of this application, the tensile strength of the first wall 111 at a temperature of 25°C is Rm, which satisfies 250MPa≤Rm≤2000MPa.

[0207] In some embodiments, the tensile strength of the first wall 111 at a temperature of 25°C is Rm, which satisfies 250MPa≤Rm≤2000MPa. This can be understood as the tensile strength of the first wall 111 at room temperature being Rm. The value of Rm can be 250MPa, 280MPa, 300MPa, 330MPa, 350MPa, 380MPa, 400MPa, 450MPa, 500MPa, 550MPa, 600MPa, 650MPa, 700MPa, 750MPa, 800MPa, or 850MPa. Pa, 900MPa, 950MPa, 1000MPa, 1050MPa, 1100MPa, 1150MPa, 1200MPa, 1250MPa, 1300MPa, 1350MPa, 1400MPa, 1450MPa, 1500MPa, 1550MPa, 1600MPa, 1650MPa, 1700MPa, 1750MPa, 1800MPa, 1850MPa, 1900MPa, 1950MPa, 2000MPa, or any value between two adjacent values.

[0208] It should be understood that the tensile strength in the embodiments of this application refers to the maximum stress value that the material can withstand before breaking. The test method for the tensile strength Rm of the first wall 111 in the embodiments of this application at a temperature of 25°C can be selected according to the actual application. For example, the national standard GB / T228.1-2010 can be used to test the tensile strength Rm at room temperature of 25°C.

[0209] Optionally, in some embodiments of this application, the material of the first wall 111 can satisfy the following conditions: firstly, the melting point is greater than or equal to 1200°C and less than or equal to 2000°C; and secondly, the tensile strength Rm at a temperature of 25°C satisfies 250MPa≤Rm≤2000MPa.

[0210] In the above scheme, on the one hand, by limiting the range of the room temperature tensile strength Rm of the first wall 111, and ensuring that this range satisfies 250MPa≤Rm≤2000MPa, the deformation resistance of this part can be high, effectively reducing the impact of external impacts on the internal structural components of the battery cell 10. Thus, under the condition of meeting the impact resistance requirements, the thickness of the first wall 111 can be reduced, which is conducive to improving the volumetric energy density of the battery cell 10, and thus conducive to improving the volumetric energy of the battery device 100. On the other hand, under the condition that the first wall 111 is thinner and has a higher melting point, the risk of structural damage to the insulating component 13 due to welding of the sealing component 14 and the first wall 111 increases. To address this, by setting a void groove on the insulating component 13, the problem of structural damage to the insulating component 13 due to the heat generated by welding can be effectively mitigated, thereby making the battery cell 10 have higher reliability, and thus making the battery device 100 have higher reliability.

[0211] According to some embodiments of this application, the following condition is met: 450MPa≤Rm≤800MPa.

[0212] In some embodiments, the tensile strength Rm of the first wall 111 at a temperature of 25°C can be 450MPa, 500MPa, 550MPa, 600MPa, 650MPa, 700MPa, 750MPa, 800MPa or any value between two adjacent values.

[0213] Optionally, in some embodiments of this application, the material of the first wall 111 can satisfy the following conditions: firstly, the melting point is greater than or equal to 1200°C and less than or equal to 2000°C; and secondly, the tensile strength Rm at a temperature of 25°C satisfies 450MPa≤Rm≤800MPa.

[0214] In the above scheme, on the one hand, limiting the tensile strength Rm of the first wall 111 under normal temperature conditions to not less than 450MPa ensures that the first wall 111 has strong resistance to deformation, thus resisting the expansion of the electrode assembly 12 or external impacts, making this part less prone to damage, reducing the risk of cracking of the outer casing 11, and thereby improving the structural stability and service life of the battery cell 10. On the other hand, controlling the tensile strength Rm of the first wall 111 under normal temperature conditions to not be too large reduces the difficulty of material selection and processing for this end wall, saves costs, and facilitates processing.

[0215] According to some embodiments of this application, the material of the first wall 111 includes one of the following materials: steel, copper alloy, titanium alloy, and nickel alloy.

[0216] In the above scheme, the material of the first wall 111 includes one of steel, copper alloy, titanium alloy and nickel alloy, so that the end wall has greater strength, can meet the strength requirements of the battery cell 10 shell 11, and is easy to process and has a lower cost.

[0217] According to some embodiments of this application, the material of the first wall 111 includes stainless steel or carbon steel.

[0218] In the above scheme, if the first wall 111 is made of stainless steel, its structural strength is relatively high, which can generally meet the tensile strength Rm requirement under the aforementioned room temperature conditions. Furthermore, the stainless steel material of the first wall 111 is not prone to rust, which, compared to other materials, improves the reliability of the joint between the end wall and the shell 110, reducing the risk of cracking of the outer shell 11. If the first wall 111 is made of carbon steel, its structural strength is high, making it easy to meet the tensile strength Rm requirement under the aforementioned room temperature conditions.

[0219] According to some embodiments of this application, the material of the sealing element 14 is the same as the material of the first wall 111.

[0220] In some embodiments, the material of the sealing member 14 is the same as that of the first wall 111, meaning that the sealing member 14, like the first wall 111, can meet the tensile strength Rm requirement under the aforementioned room temperature conditions, which also meets the aforementioned melting point requirement. Furthermore, the fact that the sealing member 14 is made of the same material as the first wall 111 reduces the difficulty of welding between the sealing member 14 and the first wall 111, thus improving the manufacturing efficiency of the battery cell 10.

[0221] For example, the first wall 111 is made of steel and the sealing member 14 is made of steel. The first wall 111 and the side sealing member 14 can be effectively combined into one piece through welding process, and the structure has high strength.

[0222] In the above scheme, the material of the sealing component 14 is the same as that of the first wall 111. That is, the sealing component 14, like the first wall 111, can meet the tensile strength Rm requirement under the above-mentioned room temperature conditions. This can improve the reliability of the joint between the first wall 111 and the sealing component 14, and reduce the risk of the first density component detaching from the first wall 111. At the same time, the fact that the material of the sealing component 14 is the same as that of the first wall 111 reduces the welding difficulty between the sealing component 14 and the first wall 111, which is beneficial to improving the manufacturing efficiency of the battery cell 10.

[0223] According to some embodiments of this application, the solder mark 140 is disposed around the central axis s of the first through hole 112.

[0224] In some embodiments, the solder mark 140 is an annular structure that can be arranged around the central axis s of the first through hole 112. Exemplarily, the solder mark 140 is a circular annular structure or a polygonal annular structure.

[0225] In the above scheme, by setting the solder mark 140 to surround the central axis s of the first through hole, the sealing member 14 and the first wall 111 can have good connection quality, effectively reducing the risk of the sealing member 14 detaching from the first wall 111, so that the sealing member 14 can effectively seal the first through hole 112, reduce the risk of electrolyte leakage, and make the battery cell 10 have high reliability, thereby making the battery device 100 have high reliability.

[0226] In some other embodiments, the solder mark 140 may not be a ring structure. For example, the solder mark 140 may include a plurality of sub-solder marks 140, which are spaced apart to jointly connect the sealing member 14 to the first wall 111.

[0227] In some other embodiments, the solder mark 140 may be a ring-shaped structure with a notch.

[0228] According to some embodiments of this application, the second groove 131 is disposed around the central axis s of the first through hole.

[0229] In some embodiments, please refer to FIG6, the second groove 131 is arranged around the outer periphery of the first through hole 112 to correspond to the solder mark 140, so that there is a certain distance between the solder mark 140 and the insulating member 13.

[0230] In the above scheme, corresponding to the solder mark 140, the second groove 131 is also set to surround the central axis s of the first through hole, which can effectively avoid the solder mark 140 to reduce the influence of the heat generated during the welding process on the insulating component 13, thereby ensuring the structural integrity of the insulating component 13 to a certain extent, making the battery cell 10 highly reliable, and thus making the battery device 100 highly reliable.

[0231] According to some embodiments of this application, the insulating member 13 has a first surface 130 facing the first wall 111, and a first groove 130a is formed on the first surface 130. Along the thickness direction z of the first wall, the minimum distance between the first surface 130 and the bottom surface of the first groove 130a is h, which satisfies 3mm≤h≤6mm.

[0232] Please refer to Figure 6. Along the thickness direction z of the first wall, the minimum distance h between the first surface 130 and the bottom surface of the first groove 130a can be understood as the groove depth of the first groove 130a.

[0233] In some embodiments, the value of h can be 3mm, 4mm, 5mm, 6mm or any value between two adjacent values.

[0234] In the above scheme, by limiting the minimum distance between the first surface 130 and the bottom surface of the first groove 130a to be no less than xx and no greater than xx, on the one hand, the sealing component 14 can utilize the space where the first groove 130a is located, making the battery cell structure compact; on the other hand, it can reduce the occupation of the insulating component 13 on the internal space of the battery cell 10, reducing the impact on the volumetric energy density of the battery cell 10; furthermore, when the first through hole 112 is used for injecting electrolyte, the first groove 130a can act as a buffer for the electrolyte, reducing the impact of the electrolyte on the internal structural components of the battery cell 10, and improving the electrolyte injection efficiency.

[0235] In some other embodiments, the value of h can also be less than 3 mm or greater than 6 mm.

[0236] According to some embodiments of this application, please refer to FIG6, the insulating member 13 includes an insulating body 136, a peripheral wall 137 and a bottom wall 138. One end of the peripheral wall 137 surrounds the edge of the bottom wall 138, and the other end of the peripheral wall 137 is connected to the insulating body 136. The peripheral wall 137 and the bottom wall 138 together form a first groove 130a, and at least a portion of the second groove 131 is formed on the side of the peripheral wall 137 facing the first wall 111.

[0237] In some embodiments, the insulating body 136 is the main part of the insulating member 13, and the side of the insulating body 136 opposite to the electrode assembly can contact the first wall 111. Along the direction of the first wall 111 toward the electrode assembly 12, the bottom wall 138 protrudes from the insulating body 136.

[0238] One end of the peripheral wall 137 is connected to the insulating body 136, and the other end extends toward the electrode assembly 12 and surrounds the outer edge of the bottom wall 138. The end of the peripheral wall 137 opposite to the bottom wall 138 forms a groove 130a.

[0239] "At least a portion of the second groove 131 is formed on the peripheral wall 137" can be understood as the second groove 131 being formed wholly or partially on the surface of the peripheral wall 137 facing the first wall 111. For example, in FIG6, a portion of the second groove 131 is formed on the surface of the peripheral wall 137, and another portion of the second groove 131 is formed on the surface of the insulating body 136.

[0240] In the above scheme, by defining at least a portion of the second groove as being formed on the peripheral wall, the insulating structure can be made compact, resulting in a high volumetric energy density of the battery cell.

[0241] Alternatively, in some other embodiments, the second groove 131 is not formed on the peripheral wall 137, but is formed on the surface of the insulating body 136.

[0242] According to some embodiments of this application, a second through hole is formed in the peripheral wall 137.

[0243] In some embodiments, the second through hole is a through hole structure formed on the peripheral wall 137, and the second through hole is used to guide the electrolyte in the first groove 130a into the inner side of the insulating member 13.

[0244] In some embodiments, the axial direction of the second through hole intersects the axial direction of the first through hole 112; for example, the axial direction of the second through hole is perpendicular to the axial direction of the first through hole 112.

[0245] In the above scheme, by forming a second through hole on the peripheral wall 137, the electrolyte does not directly impact the electrode assembly 12 when the first through hole 112 is used for electrolyte injection. This reduces the risk of damage to the electrode assembly 12 structure caused by the impact of the electrolyte during the electrolyte injection process, resulting in high reliability of the battery cell 10 and improving the reliability of the battery device.

[0246] Optionally, in some embodiments, a second through hole is formed in the bottom wall 138.

[0247] According to some embodiments of this application, on the same plane perpendicular to the thickness direction z of the first wall, the projection of the solder mark 140 and the projection of the peripheral wall 137 at least partially overlap.

[0248] Please refer to Figure 6. At least a portion of the second groove 131 is formed on the surface of the peripheral wall 137. Along the thickness direction z of the first wall, at least a portion of the solder mark 140 is projected onto the peripheral wall 137.

[0249] In the above scheme, the solder mark 140 is at least partially aligned with the peripheral wall 137. The peripheral wall 137, which has a larger z-dimensional dimension along the thickness direction of the first wall, resists the high temperature generated during welding, thereby reducing the risk of insulation failure of the insulating component 13 due to high temperature melting. This ensures the reliability of the battery cell 10 to a certain extent and is conducive to improving the reliability of the battery device 100.

[0250] In some embodiments, referring to FIG6, at least a portion of the second groove 131 is formed on the peripheral wall 137 and communicates with the first groove 130a.

[0251] In other embodiments, at least a portion of the second groove 131 is formed on the peripheral wall 137 and does not communicate with the first groove 130a. Please refer to FIG9, which is a partial structural schematic diagram of the sealing member 14, the first wall 111, and the insulating member 13 in other embodiments of this application. In these other embodiments, the second groove 131 has an annular structure, and there is a distance between the inner periphery of the second groove 131 and the first groove 130a.

[0252] According to some embodiments of this application, a weld stamp 140 penetrates the sealing member 14 along the thickness direction z of the first wall.

[0253] Optionally, as shown in Figure 6, the weld 140 penetrates the sealing member 14 along the thickness direction z of the first wall. That is, during the welding process, the heat generated by welding can melt the sealing member 14 in the thickness direction z of the first wall, and the melting direction continues along the thickness direction z of the first wall toward the first wall 111.

[0254] Optionally, along the thickness direction z of the first wall, the weld 140 penetrates the sealing member 14, and a portion of the weld 140 coincides with the first wall 111.

[0255] Optionally, along the radial x of the first through hole, the projection of a portion of the solder mark 140 coincides with the projection of the sealing member 14, and the projection of another portion of the solder mark 140 coincides with the projection of the first wall 111.

[0256] For example, please refer to Figure 6. Part of the sealing member 14 overlaps with the outer side of the first wall 111. The overlapping part is welded by welding equipment along the direction of the sealing member 14 pointing to the first wall 111. The overlapping method melts the sealing member 14 and part of the first wall 111, so that the sealing member 14 and the first wall 111 are integrated.

[0257] In the above scheme, by setting the weld mark 140 to penetrate the sealing member 14, the sealing member 14 can be effectively fixed to the first wall 111, making the welding quality between the sealing member 14 and the first wall 111 reliable, thereby making the battery cell 10 highly reliable, and thus making the battery device 100 highly reliable.

[0258] According to some embodiments of this application, please refer to Figures 6-11. Figure 10 is a schematic diagram of the first wall 111 and the insulating member 13 in some embodiments of this application, and Figure 11 is a schematic diagram of the sealing member 14 in some embodiments of this application.

[0259] Along the thickness direction z of the first wall, the first wall 111 has a second surface 113 opposite to the electrode assembly 12, and a third groove 1130 is formed on the second surface 113. The first through hole 112 penetrates the bottom wall of the third groove 1130; part of the sealing member 14 is located in the third groove 1130.

[0260] The second surface 113 can be the outer surface of the first wall 111. In some embodiments, the outer surface of the first wall 111 can form a third groove 1130, and the first through hole 112 penetrates the bottom surface of the third groove 1130. Optionally, the first wall 111 can be formed by a stamping process to form the third groove 1130. As shown in FIG10, the outer surface of the first wall 111 is stamped along the thickness direction z of the first wall to form the third groove 1130 on the outer surface of the first wall 111, and a protrusion is formed on the inner surface of the first wall 111 corresponding to the portion of the third groove 1130. The protrusion can be located within the first groove 130a.

[0261] In some embodiments, a portion of the sealing member 14 is located within the third groove 1130. Exemplarily, the sealing member 14 has a limiting portion 143 protruding from the side facing the first wall 111. The limiting portion 143 is located within the third groove 1130.

[0262] In the above scheme, by setting a third groove 1130 on the side of the first wall 111 away from the electrode assembly 12, it can play a positioning role, reduce the difficulty of assembling the sealing member 14 on the first wall 111, and thus improve the manufacturing efficiency of the battery cell 10; on the other hand, it can accommodate part of the sealing member 14, reduce the impact of the sealing member 14 on the size of the battery cell 10, and improve the volumetric energy density of the battery cell 10.

[0263] Optionally, the sealing member 14 may not be located within the third groove 1130. The sealing member 14 may be a flat plate structure, and the sealing member 14 may close the opening of the third groove 1130.

[0264] According to some embodiments of this application, please refer to FIG10, along the thickness direction z of the first wall, the distance between the second surface 113 and the bottom surface of the third groove 1130 is S, which satisfies 0.8mm≤S≤1.5mm.

[0265] In some embodiments, along the thickness direction z of the first wall, the distance S between the second surface 113 and the bottom surface of the third groove 1130 can be the groove depth of the third groove 1130, and the value of S can be 0.8mm...1.3mm, 1.4mm, 1.5mm or any value between two adjacent values.

[0266] In some embodiments, the first wall 111 has a high hardness, for example, the tensile strength of the first wall 111 at room temperature is greater than or equal to 250 MPa and less than or equal to 2000 MPa, for example, the material of the first wall 111 is steel, and the third groove 1130 can be formed on the second surface 113 of the first wall 111 by a stamping process.

[0267] In the above scheme, by limiting the distance between the second surface 113 and the bottom surface of the third groove 1130 to not less than 0.8mm, the third groove 1130 can play the role of positioning and accommodating the sealing component, thereby improving the manufacturing efficiency of the battery cell. By limiting the distance between the second surface 113 and the bottom surface of the third groove 1130 to not more than 1.5mm, the molding difficulty of the third groove 1130 is reduced, thereby improving the manufacturing efficiency of the battery cell 10 and the battery device 100.

[0268] In some other embodiments, the value of S may be less than 0.8 mm or greater than 1.5 mm.

[0269] According to some embodiments of this application, the sealing member 14 includes a main body 141 and an edge portion 142. At least a portion of the edge portion 142 is disposed around the outer periphery of the main body 141. At least a portion of the main body 141 is located in a third groove 1130. The edge portion 142 overlaps with the second surface 113. The solder mark 140 penetrates the edge portion 142.

[0270] The third groove 1130 is formed on the outer side of the first wall 111 by stamping. Because the first wall 111 has a large hardness, the collapse angle formed by stamping is large, and the groove depth of the third groove 1130 is small. In related technologies, the sealing part 14 cannot fit against the groove side of the third groove 1130, or the gap between the sealing part 14 and the groove side is large, thus failing to meet the welding requirements of flush welding.

[0271] For example, along the thickness direction z of the first wall, the projection of the main body 141 can cover the projection of the side of the groove of the third groove 1130, so as to close the first through hole 112. The edge portion 142 is located outside the third groove 1130 and overlaps the second surface 113. Wherein, along the thickness direction z of the first wall, the projection of the main body 141 can cover the projection of the collapsed corner, and there is a distance between the main body 141 and the collapsed corner.

[0272] The weld mark 140 is formed at the overlapping portion of the edge portion 142 and the first wall 111. Optionally, when assembling the sealing member 14, the edge portion 142 of the sealing member 14 can be first overlapped with the second surface 113, and a welding laser can be emitted towards the edge portion 142 in the direction of the sealing member 14 pointing towards the first wall 111. The welding laser melts a portion of the edge portion 142 and a portion of the first wall 111 located below the edge portion 142 to form the weld mark 140.

[0273] In the above solution, by overlapping the edge portion 142 with the outer side of the first wall 111 (i.e., the second surface 113) and welding the edge portion 142 and the first wall 111 by through welding, the problem that some materials with a melting point greater than or equal to 1200℃ have high hardness and are difficult to stamp grooves on their surface, and the sealing part 14 cannot be fully set in the third groove 1130, thus making it impossible to implement the flush welding process.

[0274] According to some embodiments of this application, please refer to FIG9. On the same plane perpendicular to the thickness direction z of the first wall, the minimum distance between the projection of the solder mark 140 and the projection of the bottom wall of the third groove 1130 is j, which satisfies 1mm≤j≤3mm.

[0275] In some embodiments, the solder mark 140 is located outside the third groove 1130, and the minimum distance between the solder mark 140 and the bottom wall of the third groove 1130 is j, where j can be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm...2.8 mm, 2.9 mm, 3 mm or any value between two adjacent values.

[0276] In the above scheme, the solder mark 140 is located at the overlapping part of the edge portion 142 and the second surface 113, so that there is a gap between the solder mark 140 and the third groove 1130. By limiting the distance between the solder mark 140 and the bottom wall of the third groove 1130 to not less than xx, the risk of poor soldering between the sealing component 14 and the first wall 111 can be reduced. By limiting the distance between the solder mark 140 and the bottom wall of the third groove 1130 to not greater than, the risk of interference between the solder mark 140 and other structural components located outside the first wall 111 can be reduced, making the battery device 100 structurally compact and conducive to improving the volumetric energy density of the battery device 100.

[0277] In some other embodiments, the value of j can be less than 1 mm or greater than 3 mm.

[0278] According to some embodiments of this application, please refer to FIG6. Along the thickness direction z of the first wall, the main body 141 has a limiting part 143 protruding on the side facing the first wall 111. The limiting part 143 is used to contact the groove side of the third groove 1130 to limit the radial x displacement of the sealing member 14 along the first through hole.

[0279] In some embodiments, the limiting portion 143 may be a structural member protruding from the inner side of the main body portion 141, for contacting the groove side of the third groove 1130 to limit the relative position of the sealing member 14 and the first wall 111 in the radial x direction of the first through hole.

[0280] Optionally, the limiting part 143 can be a protrusion extending inside the main body part 141. The limiting part 143 and the main body part 141 can be separate structures or they can be an integral structure. For example, the limiting part 143 and the main body part 141 are separate structures, and they are connected by means of bonding, welding, riveting, etc.

[0281] For example, the limiting part 143 and the main body 141 are integral structures, and the two are integrally formed by stamping, die casting or casting processes. Optionally, the main body 141 is stamped in the direction pointing to the first direction of the sealing member 14 to form a recess 144 on the outer side of the main body 141 and a limiting part 143 on the inner side of the main body 141.

[0282] The phrase "the limiting part 143 is used to contact the side of the groove of the third groove 1130" can be understood as follows: when the sealing member 14 is assembled onto the first wall 111, the limiting part 143 can contact the side of the groove of the third groove 1130, or there may be a gap between the limiting part 143 and the side of the groove of the third groove 1130. Even when there is a gap between the limiting part 143 and the side of the groove of the third groove 1130, the welding positioning requirements are met, allowing the edge part 142 to be welded to the first wall 111.

[0283] In the above solution, by providing a limiting part 143 on the side of the main body 141 facing the first wall 111, the sealing member 14 can be restricted from moving radially along the first through hole, which is conducive to the sealing member 14 being positioned and assembled on the first wall 111, thereby reducing the precision requirement for welding the sealing member 14 to the first wall 111, which is conducive to improving the manufacturing efficiency of the battery cell 10, and thus making the battery device 100 have a higher manufacturing efficiency.

[0284] In some other embodiments, the sealing member 14 may be generally plate-shaped and placed on the second surface 113 of the first wall 111. The middle part of the sealing member 14 closes the opening of the third groove 1130, and the edge portion 142 of the sealing member 14 overlaps the second surface 113 of the first wall 111.

[0285] In some other embodiments, the outer side of the first wall 111 may not have the third groove 1130, and the sealing member 14 may be generally plate-shaped, placed on the second surface 113 of the first wall 111, with the edge portion 142 of the sealing member 14 welded to the first wall 111.

[0286] According to some embodiments of this application, please refer to Figures 6 and 11. Along the thickness direction z of the first wall, a recess 144 is formed on the side of the main body 141 opposite to the first wall 111. The position of the recess 144 corresponds to the position of the limiting part 143.

[0287] The recess 144 can be understood as a portion that is recessed from the outer side of the sealing member 14 toward the inner side. For example, the recess 144 and the limiting portion 143 are formed by a stamping process, that is, the outer side of the sealing member 14 is stamped against the first wall 111 so that the outer side of the sealing member 14 is recessed to form the recess 144, and the inner side protrudes to form the limiting portion 143.

[0288] In the above solution, by providing a recessed portion 144 on the side of the main body 141 away from the first wall 111 and corresponding to the limiting portion 143, on the one hand, the material cost of the sealing member 14 can be saved, which is conducive to reducing the manufacturing cost of the battery cell 10; on the other hand, the area where the recessed portion 144 and the limiting portion 143 are located can improve the elastic performance of the sealing member 14, thereby reducing the risk of cracking due to stretching when the sealing member 14 and the first wall 111 are welded, or improving the sealing member 14's ability to withstand external impacts, reducing the risk of structural damage to the sealing member 14 due to external impacts, so that the battery cell 10 has higher reliability, and thus the battery device 100 has higher reliability.

[0289] According to some embodiments of this application, please refer to FIG6, the limiting portion 143 is arranged around the central axis of the sealing member 14.

[0290] The central axis of the sealing component 14 can be collinear with the central axis s of the first through hole.

[0291] Optionally, the limiting part 143 is an annular structure, which is arranged around the central axis of the sealing member 14. The outer peripheral surface of the limiting part 143 can be used to cooperate with the groove side surface of the third groove 1130 so that at any part of the circumferential direction of the limiting part 143, it can contact the groove side surface of the third groove 1130.

[0292] In the above solution, by setting the limiting part 143 to surround the central axis of the sealing part 14, the sealing part 14 can be constrained relative to the first through hole 112 in the circumferential direction, thereby stabilizing the assembly relationship between the sealing part 14 and the first wall 111, reducing the difficulty of welding the two, and improving the manufacturing efficiency of the battery cell 10.

[0293] Optionally, in some other embodiments, there are multiple limiting portions 143, and the multiple limiting portions 143 can be spaced apart around the central axis of the sealing member 14.

[0294] According to some embodiments of this application, please refer to Figures 4 and 6. The battery cell 10 also includes a seal 15 disposed in the first through hole 112.

[0295] Optionally, the sealing element 15 is a sealing structure disposed in the first through hole 112. For example, the sealing element 15 can be a rubber nail, which is inserted into the first through hole 112 and deformed by being squeezed by the hole wall of the first through hole 112, thereby forming a seal.

[0296] For example, the sealing member 14 is a metal sealing nail. Along the thickness direction z of the first wall, the projection of the main body portion 141 of the sealing member 14 can cover the projection of the sealing member 15. Along the radial direction x of the first through hole, the projection of the edge portion 142 can be spaced apart from the projection of the sealing member 15. That is, the solder mark 140 is far away from the sealing member 15 in the radial direction x of the first through hole, thereby reducing the impact of the heat generated by the welding of the sealing member 14 and the first wall 111 on the sealing member 15.

[0297] In the above solution, by setting the sealing element 15 to block the first through hole 112, the risk of electrolyte leakage can be effectively reduced, which is conducive to improving the reliability of the battery cell 10.

[0298] In some embodiments of this application, as shown in FIG2, the battery device 100 may further include a housing 20, in which the battery cell 10 is housed.

[0299] In some embodiments, the housing 20 may include a first housing body 21 and a second housing body 22, the first housing body 21 and the second housing body 22 covering each other, the first housing body 21 and the second housing body 22 together defining an assembly space for accommodating the battery cell 10.

[0300] Optionally, the second box body 22 can be a hollow structure with one end open, and the first box body 21 can be a plate-like structure. The first box body 21 covers the open side of the second box body 22 so that the first box body 21 and the second box body 22 together define the assembly space; the first box body 21 and the second box body 22 can also be hollow structures with one side open, and the open side of the first box body 21 covers the open side of the second box body 22.

[0301] Of course, the box 20 formed by the first box body 21 and the second box body 22 can be of various shapes, such as a cylinder or a cuboid. For example, in Figure 2, the box 20 is a cuboid structure.

[0302] Optionally, the battery cell 10 disposed within the housing 20 can be one or more. For example, in Figure 2, the housing 20 of the battery device 100 contains multiple battery cells 10, which can be connected in series, parallel, or a combination thereof. A combination thereof means that some of the battery cells 10 are connected in series and others in parallel. Multiple battery cells 10 can be directly connected in series, parallel, or a combination thereof, and then the entire assembly of the multiple battery cells 10 is housed within the housing 20. Alternatively, the battery device 100 can also consist of multiple battery cells 10 first connected in series, parallel, or a combination thereof to form a battery module, and then these battery modules are connected in series, parallel, or a combination thereof to form a whole, which is then housed within the housing 20.

[0303] 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 10 to achieve electrical connection between the multiple battery cells 10.

[0304] It should be noted that in some embodiments, the battery device 100 may not have a housing 20. The battery device 100 includes multiple battery cells 10, and the battery device 100 composed of multiple battery cells 10 can be directly mounted onto the electrical device to provide power to the electrical device through the multiple battery cells 10. That is, the housing 20 can be part of the electrical device. Taking a vehicle 1000 as an example, the housing 20 can be part of the chassis structure of the vehicle 1000. For example, a portion of the housing 20 can be at least a part of the floor of the vehicle 1000, or a portion of the housing 20 can be at least a part of the crossbeams and longitudinal beams of the vehicle 1000.

[0305] Some embodiments of this application also provide an electrical device, which includes the battery cell 10 provided above and / or the battery device 100 provided above, wherein the battery cell 10 is used to provide electrical energy.

[0306] The electrical device can be any of the aforementioned devices or systems that utilize battery cells 10 and / or battery devices 100. For example, the electrical device can be a vehicle 1000, which can be a range-extended vehicle 1000, a pure electric vehicle 1000, or a gasoline-powered vehicle 1000. The electrical energy provided by the battery cells 10 can be used to meet the power needs of the vehicle 1000 during startup, navigation, and operation.

[0307] Some embodiments of this application provide a battery cell 10, as shown in Figures 3-11. The battery cell 10 includes a housing 11, an electrode assembly 12, an insulating member 13, and a sealing member 14. The housing 11 is a steel shell and has a first wall 111. The thickness of the first wall 111 is no more than 1.5 mm. The insulating member 13 is disposed inside the housing 11 and is located between the first wall 111 and the electrode assembly 12.

[0308] The first wall 111 has a first through hole 112. The first through hole 112 is a liquid injection hole. Referring to FIG10, the first wall 111 has a second surface 113 facing away from the electrode assembly 12, and a third groove 1130 is formed on the second surface 113. Exemplarily, the second surface 113 is the outer surface of the first wall 111. The outer surface of the first wall 111 is stamped to form the third groove 1130 on the outer surface of the first wall 111, and a protrusion is formed on the inner surface of the first wall 111 corresponding to the portion of the third groove 1130. The first through hole 112 penetrates the bottom surface of the third groove 1130.

[0309] The sealing member 14 includes a main body 141 and an edge portion 142. At least a portion of the main body 141 is located in a third groove 1130. For example, a limiting portion 143 protrudes from the side of the main body 141 facing the bottom surface of the third groove 1130. The limiting portion 143 can abut against the bottom surface of the third groove 1130 to limit the displacement of the sealing member 14 relative to the first wall 111 along the radial x of the first through hole. The edge portion 142 overlaps with a second surface 113. The sealing member 14 and the first wall 111 are connected by a solder mark 140 located at the position where the edge portion 142 and the first wall 111 overlap. Exemplarily, the sealing member 14 and the first wall 111 can be connected by through welding, for example, by welding along the side of the edge portion 142 away from the first wall 111, such that the solder mark 140 penetrates the edge portion 142.

[0310] Along the thickness direction z of the first wall, the insulating member 13 has a first surface 130 facing the first wall 111. The first surface is formed with a first groove 130a and a second groove. The first groove 130a is provided corresponding to the first through hole 112, and the portion of the protrusion formed on the inner side of the first wall 111 corresponding to the portion of the third groove 1130 is located in the first groove 130a.

[0311] For example, the insulating member 13 includes an insulating body 136, a peripheral wall 137 and a bottom wall 138. The peripheral wall 137 and the bottom wall 138 are located inside the insulating body 136 and protrude toward the electrode assembly 12. The peripheral wall 137 and the bottom wall 138 together form a first groove 130a. The peripheral wall 137 has a second through hole for guiding electrolyte into the inner side of the insulating member 13.

[0312] The projection of the solder mark 140 falls on the bottom surface of the second groove 131. Along the radial direction x of the first through hole, the minimum distance between the solder mark 140 and the outer periphery of the second groove 131 is L, satisfying 0.5mm ≤ L ≤ 3mm. Along the thickness direction z of the first wall, the minimum distance between the first surface 130 and the bottom surface of the second groove 131 is H, satisfying 0.1mm ≤ H ≤ 0.3mm.

[0313] In the above solution, by providing a second groove 131 on the side of the insulating component 13 facing the first wall 111 and corresponding to the solder mark 140, a certain distance can be maintained between the part of the insulating component 13 corresponding to the solder mark 140 and the welding part. This reduces the impact of the heat generated during the welding process of the sealing component 14 and the first wall 111 on the insulating component 13, and to a certain extent ensures the structural integrity of the insulating component 13. This allows the insulating component 13 to effectively perform its insulating function, thereby increasing the reliability of the battery cell 10 and the battery device 100.

[0314] 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, wherein, include: The outer casing includes a first wall having a first through hole, and the melting point of the first wall is greater than or equal to 1200°C and less than or equal to 2000°C. Electrode assembly, disposed within the housing; An insulating element is disposed within the housing and located between the first wall and the electrode assembly; A sealing element is welded to the first wall and the sealing element closes the first through hole. The connection area between the sealing element and the first wall forms a weld mark, and the weld mark is at least partially exposed on the side of the first wall away from the electrode assembly. The insulating component has a first groove and a second groove recessed toward the electrode assembly. The second groove is at least partially circumferentially disposed around the outer periphery of the first groove. On the same plane perpendicular to the thickness direction of the first wall, the projection of the first groove and the projection of the first through hole at least partially coincide, and the projection of the second groove and the projection of the solder mark at least partially coincide.

2. The battery cell according to claim 1, wherein, Along the radial direction of the first through hole, the minimum distance between the solder mark and the outer periphery of the second groove is L, which satisfies 0.3mm≤L≤3.2mm.

3. The battery cell according to claim 2, wherein, The following condition is met: 0.5mm≤L≤3mm.

4. The battery cell according to any one of claims 1-3, wherein, The insulating member has a first surface facing the first wall, and the second groove is formed on the first surface. Along the thickness direction of the first wall, the minimum distance between the first surface and the bottom surface of the second groove is H, which satisfies 0.05mm≤H≤0.5mm.

5. The battery cell according to claim 4, wherein, It satisfies the condition 0.1mm≤H≤0.3mm.

6. The battery cell according to any one of claims 1-5, wherein, The thickness of the first wall is no more than 1.5 mm.

7. The battery cell according to any one of claims 1-6, wherein, The tensile strength of the first wall at a temperature of 25℃ is Rm, which satisfies 250MPa≤Rm≤2000MPa.

8. The battery cell according to claim 7, wherein, The following conditions must be met: 450MPa≤Rm≤800MPa.

9. The battery cell according to claim 8, wherein, The material of the first wall includes one of the following: steel, copper alloy, titanium alloy, and nickel alloy.

10. The battery cell according to claim 8 or 9, wherein, The material of the first wall includes stainless steel or carbon steel.

11. The battery cell according to any one of claims 1-10, wherein, The sealing element is made of the same material as the first wall.

12. The battery cell according to any one of claims 1-11, wherein, The solder mark is arranged around the central axis of the first through hole.

13. The battery cell according to claim 12, wherein, The second groove is arranged around the central axis of the first through hole.

14. The battery cell according to any one of claims 1-13, wherein, The insulating member has a first surface facing the first wall, and the first groove is formed on the first surface. Along the thickness direction of the first wall, the minimum distance between the first surface and the bottom surface of the first groove is h, which satisfies 3mm≤h≤6mm.

15. The battery cell according to claim 14, wherein, The insulating element includes an insulating body, a peripheral wall, and a bottom wall. One end of the peripheral wall surrounds the edge of the bottom wall, and the other end of the peripheral wall is connected to the insulating body. The peripheral wall and the bottom wall together form the first groove, and at least a portion of the second groove is formed on the side of the peripheral wall facing the first wall.

16. The battery cell according to claim 15, wherein, A second through hole is formed in the peripheral wall.

17. The battery cell according to claim 15 or 16, wherein, On the same plane perpendicular to the thickness direction of the first wall, the projection of the solder mark and the projection of the peripheral wall at least partially overlap.

18. The battery cell according to any one of claims 1-16, wherein, Along the thickness direction of the first wall, the first wall has a second surface opposite to the electrode assembly, the second surface is formed with a third groove, and the first through hole penetrates the bottom wall of the third groove; part of the sealing member is located in the third groove.

19. The battery cell according to claim 18, wherein, Along the thickness direction of the first wall, the distance between the second surface and the bottom surface of the third groove is S, which satisfies 0.8mm≤S≤1.5mm.

20. The battery cell according to claim 18 or 19, wherein, The sealing member includes a main body and an edge portion. At least a portion of the edge portion is circumferentially disposed around the outer periphery of the main body portion. At least a portion of the main body portion is located in the third groove. The edge portion overlaps the second surface. The solder mark penetrates the edge portion.

21. The battery cell according to claim 20, wherein, On the same plane perpendicular to the thickness direction of the first wall, the minimum distance between the projection of the solder mark and the projection of the bottom wall of the third groove is j, which satisfies 1mm≤j≤3mm.

22. The battery cell according to claim 20 or 21, wherein, Along the thickness direction of the first wall, a limiting part is provided on the side of the main body facing the first wall. The limiting part is used to contact the groove side of the third groove to limit the radial displacement of the sealing member along the first through hole.

23. The battery cell according to claim 22, wherein, Along the thickness direction of the first wall, a recess is formed on the side of the main body that is away from the first wall, and the position of the recess corresponds to the position of the limiting part.

24. The battery cell according to claim 22 or 23, wherein, The limiting part is arranged around the central axis of the sealing member.

25. The battery cell according to any one of claims 1-24, wherein, The battery cell also includes a sealing element disposed in the first through hole.

26. A battery device, wherein, Includes the battery cell described in any one of claims 1-25.

27. An electrical appliance, wherein, Includes the battery cell according to any one of claims 1-25, and / or the battery device according to claim 26, wherein the battery cell is used to provide electrical energy.

Images