Battery monomer, battery and electric equipment

Abstract

The invention relates to a battery monomer (10), a battery and electric equipment. The battery monomer (10) comprises a shell (1), an electrode assembly (2), a separator (4) and a pressure relief mechanism (131), the shell (1) is provided with a first wall portion (13), the pressure relief mechanism (131) is arranged on the first wall portion (13), the electrode assembly (2) is contained in the shell (1), and the electrode assembly (2) and the first wall portion (13) are oppositely arranged in the first direction (z). The separator (4) is arranged between the first wall part (13) and the electrode assembly (2), the separator (4) is provided with an avoiding space (41), at least part of the projection of the pressure relief mechanism (131) is located in the avoiding space (41) in the first direction (Z), and the avoiding space (41) is configured to avoid the pressure relief mechanism (131). By providing the separator (4) between the first wall portion (13) and the electrode assembly (2), the distance between the electrode assembly (2) and the first wall portion (13) is increased, and since the separator (4) is provided with the avoidance space (41) which can avoid the pressure relief mechanism (131), direct impact of the separator (4) on the pressure relief mechanism (131) when the electrode assembly (2) is expanded and deformed or the first wall portion (13) is deformed by external force is reduced, and the pressure relief mechanism (131) is prevented from being damaged. And therefore, the service life of the battery monomer (10) is effectively prolonged.

Description

Battery cells, batteries and electrical equipment

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

[0002] In recent years, new energy vehicles have experienced rapid development. In the field of electric vehicles, power batteries, as the power source, play an irreplaceable and crucial role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also increasing. As the demand for batteries grows, higher requirements are being placed on the reliability of individual battery cells.

[0003] In battery technology, it is necessary to consider not only the reliability of individual battery cells but also their lifespan. Therefore, improving the lifespan of individual battery cells is a pressing issue that needs to be addressed in battery technology.

[0004] Summary of the Invention

[0005] This application provides a battery cell, a battery, and an electrical device, which can effectively improve the service life of the battery cell.

[0006] In a first aspect, embodiments of this application provide a battery cell, including a housing, a pressure relief mechanism, an electrode assembly, and a separator; the housing has a first wall; the pressure relief mechanism is disposed on the first wall and configured to open at least partially when the battery cell is depressurized; the electrode assembly is housed within the housing and is disposed opposite to the first wall along a first direction; the separator is disposed between the first wall and the electrode assembly, and the separator has a clearance space, wherein the projection of the pressure relief mechanism is at least partially located within the clearance space along the first direction, and the clearance space is configured to avoid the pressure relief mechanism.

[0007] In the above technical solution, by setting a separator between the first wall and the electrode assembly, the distance between the electrode assembly and the first wall is increased, reducing the risk of the electrode assembly directly impacting the pressure relief mechanism and causing damage to the pressure relief mechanism when the electrode assembly expands and deforms or the first wall is deformed by external force. At the same time, since the separator is provided with a clearance space, the clearance space can avoid the pressure relief mechanism, reducing the risk of the separator directly impacting the pressure relief mechanism and causing damage to the pressure relief mechanism when the electrode assembly expands and deforms or the first wall is deformed by external force, thereby effectively improving the service life of the battery cell.

[0008] In some embodiments, the clearance space is a through hole extending through both ends of the separator along a first direction. The clearance space can serve as a venting channel, facilitating the flow of emissions from the battery cell located on the side of the separator facing the electrode assembly through the clearance space to the pressure relief mechanism.

[0009] In some embodiments, the projection of the separator does not overlap with the projection of the pressure relief mechanism along the first direction. This further reduces the impact of the separator on the pressure relief mechanism and further reduces the risk of damage to the pressure relief mechanism caused by the separator directly impacting it when the electrode assembly expands or deforms or the first wall is deformed by external force.

[0010] In some embodiments, the pressure relief mechanism includes a weak portion configured to at least partially crack upon depressurization of the battery cell, wherein the projection of the weak portion lies entirely within a clearance space along a first direction. Upon depressurization of the battery cell, the pressure relief mechanism can crack at the location of the weak portion to achieve at least partial opening of the mechanism, thereby releasing the pressure inside the battery cell. The fact that the projection of the weak portion lies within the clearance space effectively reduces the impact of the separator on the weak portion, lowering the risk of premature cracking due to impact.

[0011] In some embodiments, the housing includes a sidewall surrounding a first wall portion, the first wall portion being disposed at one end of the sidewall along a first direction; an electrode assembly has a first tab formed at one end along the first direction near the first wall portion, a first flow channel is formed between the first tab and the sidewall, a separator directly or indirectly abuts against the first tab along the first direction, and the separator is provided with a second flow channel, the second flow channel connecting the first flow channel and the clearance space. When a battery cell experiences thermal runaway, the emissions located on the side of the electrode assembly flow to the first flow channel, and then the emissions can enter the clearance space through the second flow channel on the separator, allowing the emissions to quickly reach the vicinity of the pressure relief mechanism, enabling the pressure relief mechanism to open and release pressure in a timely manner, reducing the risk of battery cell explosion and fire, and effectively improving the reliability of the battery cell.

[0012] In some embodiments, the electrode assembly has a first tab formed at one end near the first wall portion along a first direction. The separator includes a ring body and a plurality of protrusions. Along the first direction, the ring body has opposing first and second surfaces, and a clearance space extends through the first and second surfaces. The plurality of protrusions are circumferentially spaced on the ring body, and at least partially protrude from the first surface. A second flow channel is formed between the portions of two adjacent protrusions protruding from the first surface, and the second flow channel communicates with the clearance space. Along the first direction, one of the ring body and the protrusions directly or indirectly abuts against the first tab, and the first wall portion directly or indirectly abuts against the other of the ring body and the protrusions. Because one of the ring body and the protrusions directly or indirectly abuts against the first tab, and the first wall portion directly or indirectly abuts against the other of the ring body and the protrusions, the intermediate member is supported between the first tab and the first wall portion. The intermediate member can restrict the movement of the electrode assembly towards the first wall portion, reducing the risk of the electrode assembly shifting within the housing along the first direction. Because the second flow channel between two adjacent protrusions connects to the clearance space of the separator, when a battery cell experiences thermal runaway, the emissions located on the side of the electrode assembly can enter the clearance space through the second flow channel between the two adjacent protrusions. This allows the emissions to quickly reach the vicinity of the pressure relief mechanism, enabling the pressure relief mechanism to open and release pressure in a timely manner. This reduces the risk of battery cell explosion and fire, effectively improving the reliability of the battery cell. In other words, the second flow channel and the clearance space can form a channel for emissions to pass through between the electrode assembly and the first wall, allowing emissions located on the side of the electrode assembly to flow quickly towards the pressure relief mechanism.

[0013] In some embodiments, the battery cell includes a first current collector disposed between a separator and a first tab along a first direction. The first current collector is electrically connected to the separator and the first tab, and a first wall portion is electrically connected to the separator. Along the first direction, a protrusion directly abuts against the first current collector, the first current collector directly abuts against the first tab, and the first wall portion directly abuts against the ring body. By providing a first current collector between the separator and the first tab, the electrical connection between the first tab and the separator can be achieved, reducing the difficulty of the electrical connection between the first tab and the separator. The protrusion directly abuts against the first current collector, and the first wall portion directly abuts against the ring body, so that a second flow channel is formed on the side of the separator facing the electrode assembly, allowing the emissions located on the side of the electrode assembly during thermal runaway of the battery cell to enter the second flow channel more quickly.

[0014] In some embodiments, the ring body is welded to the first wall portion to form a first solder mark area, and at least one protrusion is welded to the first current collector to form a second solder mark area. Along the first direction, the projections of the first solder mark area and the second solder mark area do not overlap. This reduces the mutual interference between the first solder mark area and the second solder mark area, and reduces the risk of incomplete soldering when the ring body is welded to the first wall portion or the protrusion is welded to the first current collector.

[0015] In some embodiments, the protrusion includes a first portion, which includes a first bend and a first connecting portion. The first bend is connected to the outer peripheral surface of the ring body, and the first connecting portion is connected to the first bend. The first connecting portion is at least partially located on the side of the first surface opposite to the second surface. This structure, where the first portion is connected to the outer peripheral surface of the ring body and partially bent at the side of the first surface opposite to the second surface, has a simple structure, thus reducing the difficulty of forming the protrusion. Furthermore, since the first bend is connected to the outer peripheral surface of the ring body, it does not occupy the internal space of the ring body, increasing the clearance space and improving the clearance space's ability to avoid pressure relief mechanisms and guide the flow of discharged materials.

[0016] In some embodiments, a gap is formed between the first connecting portion and the first surface along a first direction. This gap allows the separator to act as a buffer between the first wall portion and the electrode assembly, absorbing impact forces on the first wall portion and reducing the risk of damage to the electrode assembly caused by external impacts. Furthermore, the gap between the first connecting portion and the first surface allows communication between two adjacent second flow channels. When emissions from the electrode assembly side flow into one of the second flow channels, the emissions can flow through the first gap to the other adjacent second flow channel, allowing the emissions to enter the clearance space more quickly.

[0017] In some embodiments, the first connecting portion includes a second bending portion and a plurality of first stacked portions, the plurality of first stacked portions being located on the side of the first surface opposite to the second surface, and the plurality of first stacked portions being arranged along a first direction; the second bending portion connects two adjacent first stacked portions. This structure can increase the height of the protrusion protruding from the first surface, thereby increasing the size of the second guide channel in the first direction and improving the smoothness of the flow of the discharge within the second guide channel.

[0018] In some embodiments, two adjacent first stacked portions are spaced apart along a first direction. This allows a second gap to be formed between the two adjacent first stacked portions, enabling the first connecting portion to act as a buffer between the first wall portion and the electrode assembly, absorbing the impact force on the first wall portion and reducing the risk of damage to the electrode assembly caused by external impacts to the first wall portion. Furthermore, the second gap formed between the two adjacent first stacked portions can connect two adjacent second flow channels. When emissions located on the side of the electrode assembly flow concentrated towards one of the second flow channels, the emissions can flow through the second gap to the other adjacent second flow channel, allowing the emissions to enter the clearance space more quickly.

[0019] In some embodiments, along a first direction, the first stack portion furthest from the first surface is connected to the first bend portion; or, along a first direction, the first stack portion closest to the first surface is connected to the first bend portion.

[0020] In some embodiments, the first part is integrally bent from a sheet metal. This structure offers high structural stability and is easy to form.

[0021] In some embodiments, the protrusion includes a second portion, which includes a third bend and a second connecting portion. The third bend is connected to the inner circumferential surface of the ring, and the second connecting portion is connected to the third bend. The second connecting portion is at least partially located on the side of the first surface opposite to the second surface, and the second connecting portion and the first connecting portion are arranged along a first direction. Specifically, the first connecting portion is closer to the first surface along the first direction than the second connecting portion; or, the second connecting portion is closer to the first surface along the first direction than the first connecting portion. The arrangement of the second connecting portion of the second portion and the first connecting portion of the first portion along the first direction increases the height of the protrusion from the first surface, thereby increasing the size of the second flow channel in the first direction and improving the smoothness of the flow of the discharge within the second flow channel.

[0022] In some embodiments, the protrusion includes a second portion, which includes a third bend and a second connecting portion. The third bend is connected to the inner circumferential surface of the ring body, and the second connecting portion is connected to the third bend. The second connecting portion is at least partially located on the side of the first surface opposite to the second surface. This structure, where the second portion is connected to the inner circumferential surface of the ring body and partially bent at the side of the first surface opposite to the second surface, has a simple structure, thus reducing the molding difficulty of the protrusion. Furthermore, since the third bend is connected to the inner circumferential surface of the ring body, the circumferential dimension of the third bend can be reduced, thus reducing the material used for the third bend.

[0023] In some embodiments, the second connecting portion is spaced apart from the first surface along the first direction. This allows a third gap to be formed between the second connecting portion and the first surface, enabling the separator to act as a buffer between the first wall portion and the electrode assembly, absorbing the impact force on the first wall portion and reducing the risk of damage to the electrode assembly caused by external impacts to the first wall portion. Furthermore, the third gap between the second connecting portion and the first surface allows communication between two adjacent second flow channels. When emissions from the electrode assembly side flow concentrated into one of the second flow channels, the emissions can flow through the third gap to the other adjacent second flow channel, allowing the emissions to enter the clearance space more quickly.

[0024] In some embodiments, the second connecting portion includes a fourth bend and a plurality of second stacked portions, the plurality of second stacked portions being located on the side of the first surface opposite to the second surface, and the plurality of second stacked portions being arranged along a first direction; the fourth bend connects two adjacent second stacked portions. This structure can increase the height of the protrusion protruding from the first surface, thereby increasing the size of the second guide channel in the first direction and improving the smoothness of the flow of the discharge within the second guide channel.

[0025] In some embodiments, adjacent second-layer stacks are spaced apart along a first direction. This creates a fourth gap between adjacent second-layer stacks, allowing the second connection portion to act as a buffer between the first wall and the electrode assembly, absorbing impact forces on the first wall and reducing the risk of damage to the electrode assembly caused by external impacts. Furthermore, the fourth gap between adjacent second-layer stacks can connect to adjacent second flow channels. When emissions from the electrode assembly side flow towards one second flow channel, the emissions can flow through the fourth gap to the other adjacent second flow channel, allowing the emissions to enter the clearance space more quickly.

[0026] In some embodiments, along the first direction, a second layered portion furthest from the first surface is connected to a third bend; or, along the first direction, a second layered portion closest to the first surface is connected to a third bend.

[0027] In some embodiments, the second part is integrally bent from a sheet material. This structure offers high structural stability and is easy to form.

[0028] In some embodiments, the minimum thickness of the ring body along the first direction is D, where D ≥ 0.3 mm. This ensures that the ring body has sufficient thickness, providing both adequate structural strength and a sufficiently large distance between the electrode assembly and the first wall. This further reduces the risk of damage to the pressure relief mechanism caused by the electrode assembly directly impacting the pressure relief mechanism when the electrode assembly expands or the first wall deforms under external force.

[0029] In some embodiments, the separator is electrically connected to the first wall and the first tab. Along the circumference of the ring, the sum of the maximum dimensions of all protrusions is A1, and the sum of the maximum dimensions of all second flow channels is A2, where 0.1 ≤ A1 / (A1+A2) ≤ 0.8. A1 / (A1+A2) ≥ 0.1 ensures that the proportion of the dimensions of all protrusions in the circumference of the ring is not too small, and that all protrusions have sufficient contact area with the components they directly abut against, achieving stable flow. A1 / (A1+A2) ≤ 0.8 ensures that the proportion of the dimensions of all second flow channels in the circumference of the ring is not too small, and that the discharge from the side of the electrode assembly can quickly enter the clearance space, allowing the pressure relief mechanism to open and release pressure more promptly.

[0030] In some embodiments, the separator electrically connects the first wall portion and the electrode assembly. The separator not only separates the first wall portion and the electrode assembly but also electrically connects them.

[0031] In some embodiments, the battery cell includes a first current collector, which is disposed between a separator and an electrode assembly along a first direction. The first current collector electrically connects the separator and the electrode assembly, and the projection of the first current collector along the first direction covers the clearance space. By providing a first current collector between the separator and the electrode assembly, the electrical connection between the electrode assembly and the separator can be achieved, reducing the difficulty of electrically connecting the electrode assembly and the separator.

[0032] In some embodiments, the separator is welded to the first wall portion to form a first solder mark area, and the separator is welded to the first current collector to form a second solder mark area. Along the first direction, the projections of the first solder mark area and the second solder mark area do not overlap. This reduces the mutual interference between the first solder mark area and the second solder mark area, and reduces the risk of incomplete soldering when the separator is welded to the first wall portion or the first current collector.

[0033] In some embodiments, a first tab is formed at one end of the electrode assembly near the first wall along a first direction, and the material of the first tab is different from the material of the first wall. The material of the first current collector is the same as the material of the first tab, and the first current collector is welded to the first tab. The material of the separator is the same as the material of the first wall, and the separator is welded to the first wall. The first current collector and the separator are combined and connected. The fact that the material of the first current collector is the same as the material of the first tab reduces the welding difficulty between the first current collector and the first tab, improves the weld strength after welding, and achieves stable current flow between the first current collector and the first tab. Similarly, the fact that the material of the separator is the same as the material of the first wall reduces the welding difficulty between the separator and the first wall, improves the weld strength after welding, and achieves stable current flow between the separator and the first wall. The combined connection of the first current collector and the separator achieves stable current flow between the first current collector and the separator, thereby achieving stable current flow between the first wall and the first tab.

[0034] In some embodiments, the electrode assembly is provided with a first central hole, and the first current collector is provided with a second central hole, the second central hole connecting the first central hole and the clearance space. In the event of thermal runaway of a single battery cell, emissions generated by the electrode assembly can sequentially pass through the first and second central holes into the clearance space, allowing the pressure relief mechanism to open and release pressure more promptly.

[0035] In some embodiments, the first wall portion includes a wall body and an abutment portion. The wall body is provided with a pressure relief mechanism, and the abutment portion is disposed around the outer edge of the wall body. Along a first direction, the abutment portion protrudes from the wall body in a direction close to the electrode assembly and directly or indirectly abuts against the separator. This increases the distance between the pressure relief mechanism and the separator, thereby further reducing the impact of the separator on the pressure relief mechanism and further reducing the risk of damage to the pressure relief mechanism caused by the separator directly impacting the pressure relief mechanism when the electrode assembly expands or deforms or the first wall portion is deformed by external force.

[0036] In some embodiments, the housing includes a sidewall separately disposed from the first wall portion, the sidewall surrounding the first wall portion, and the first wall portion being disposed at one end of the sidewall along a first direction; at least a portion of the abutment portion is received within the sidewall and forms a positioning engagement with the sidewall. The separate disposal of the first wall portion and the sidewall facilitates the installation of the electrode assembly into the housing. The positioning engagement between the abutment portion and the sidewall effectively reduces the assembly difficulty between the first wall portion and the sidewall.

[0037] In some embodiments, the pressure relief mechanism is integrally formed with the first wall portion; or, the pressure relief mechanism is separately disposed from the first wall portion, with the pressure relief mechanism mounted on the first wall portion. Integrating the pressure relief mechanism with the first wall portion forms a one-piece pressure relief mechanism, which offers higher reliability, eliminates the need for installation, and is more economical. Separating the pressure relief mechanism from the first wall portion and mounting it on the first wall portion makes the pressure relief mechanism a component independent of the housing, allowing for separate production and assembly of the pressure relief mechanism and housing, resulting in lower production difficulty and higher efficiency.

[0038] In some embodiments, the housing includes a shell and an end cap; the shell has an opening at at least one end along a first direction; the end cap closes the opening; wherein at least one end cap is a first wall portion. The fact that at least one end cap is a first wall portion allows for the provision of a pressure relief mechanism, reducing the difficulty of molding or installing the pressure relief mechanism.

[0039] In some embodiments, the battery cell is a cylindrical battery cell.

[0040] Secondly, embodiments of this application provide a battery, including the battery cell provided in any one of the embodiments of the first aspect.

[0041] Thirdly, embodiments of this application provide an electrical device, including a battery cell provided in any one of the embodiments of the first aspect, wherein the battery cell is used to provide electrical energy to the electrical device.

[0042] 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.

[0043] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0044] Figure 2 is an exploded view of a battery provided in some embodiments of this application;

[0045] Figure 3 is an exploded view of a single battery cell provided in some embodiments of this application;

[0046] Figure 4 is a cross-sectional view of the battery cell shown in Figure 3;

[0047] Figure 5 is a partial enlarged view of the battery cell shown in Figure 4;

[0048] Figure 6 is a partial view of a battery cell provided in some other embodiments of this application;

[0049] Figure 7 is an exploded view of a battery cell provided in some embodiments of this application;

[0050] Figure 8 is a cross-sectional view of the battery cell shown in Figure 7;

[0051] Figure 9 is a partial enlarged view of the battery cell shown in Figure 8;

[0052] Figure 10 is an isometric view of the separator shown in Figure 9;

[0053] Figure 11 is a cross-sectional view of the separator shown in Figure 10;

[0054] Figure 12 is a view of the separator shown in Figure 11 from direction A;

[0055] Figure 13 is a partial view of a battery cell (the protrusion includes a first part, which is connected to the outer peripheral surface of the ring) provided in some embodiments of this application;

[0056] Figure 14 is an isometric view of the separator shown in Figure 13;

[0057] Figure 15 is a partial view of a battery cell (the protrusion includes a first part, which is connected to the outer peripheral surface of the ring) provided in some other embodiments of this application;

[0058] Figure 16 is an isometric view of the separator shown in Figure 15;

[0059] Figure 17 is a partial view of a battery cell (the protrusion includes a first part and a second part, the first part is connected to the outer peripheral surface of the ring body, and the second part is connected to the inner peripheral surface of the ring body) provided in some embodiments of this application;

[0060] Figure 18 is an isometric view of the separator shown in Figure 17;

[0061] Figure 19 is a partial view of a battery cell (the protrusion includes a first part and a second part, the first part is connected to the outer peripheral surface of the ring body, and the second part is connected to the inner peripheral surface of the ring body) provided in some other embodiments of this application;

[0062] Figure 20 is an isometric view of the separator shown in Figure 19;

[0063] Figure 21 is a partial view of a battery cell (the first part is connected to the inner circumferential surface of the ring) provided in some embodiments of this application;

[0064] Figure 22 is an isometric view of the separator shown in Figure 21;

[0065] Figure 23 is a partial view of a battery cell (the protrusion includes a second part, which is connected to the inner circumferential surface of the ring) provided in some other embodiments of this application;

[0066] Figure 24 is an isometric view of the separator shown in Figure 23;

[0067] Figure 25 is a partial view of a battery cell (the protrusion includes a second part, which is connected to the inner circumferential surface of the ring) provided in some embodiments of this application;

[0068] Figure 26 is an isometric view of the separator shown in Figure 25;

[0069] Figure 27 is a schematic diagram of the structure of the first wall portion provided in some embodiments of this application;

[0070] Figure 28 is a cross-sectional view of the first wall shown in Figure 27.

[0071] Icons: 1-Outer shell; 11-Housing shell; 12-End cap; 13-First wall portion; 131-Pressure relief mechanism; 1311-Weak section; 1312-Pressure relief area; 132-Wall body; 1321-Third surface; 133-Abutting part; 134-Flow guiding space; 135-Edge portion; 136-Pressure relief groove; 137-Groove; 138-Groove bottom wall; 1381-Recess; 1382-Reinforcing rib ; 14-Sidewall; 141-Inner circumferential surface of sidewall; 2-Electrode assembly; 21-Main body; 22-First electrode tab; 23-Second electrode tab; 24-First central hole; 3-Electrode terminal; 4-Separator; 41-Clearing space; 42-Second flow channel; 43-Ring body; 431-First surface; 432-Second surface; 433-Outer circumferential surface of ring body; 434-Inner circumferential surface of ring body; 44-Protrusion; 441-First part; 4411-First bend; 4412-First connecting part; 44121-Second bend; 44122-First stacked part; 4413-First gap; 4414-Second gap; 442-Second part; 4421-Third bend; 4422-Second connecting part; 44221-Fourth bend; 44222-Second stacked part; 4423-Third gap; 4424-Fourth gap; 45-First soldering area; 46-Second soldering area; 5-First current collector; 51-Second center hole; 6-Second current collector; 7-First current guide channel; 10-Battery cell; 20-Box; 201-First box; 202-Second box; 100-Battery; 200-Controller; 300-Motor; 1000-Vehicle; Z-First direction; X-Circumferential direction of the ring.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] In this application, "multiple" means two or more (including two).

[0078] 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.

[0079] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0080] 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, reduces the risk of short circuits while allowing active ions to pass through.

[0081] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0082] 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.

[0083] 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.).

[0084] 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 NCM) 211 LiNi 0.6 Co 0.2 Mn0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0085] 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.

[0086] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative current collector.

[0087] 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, carbon, 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.).

[0088] As an example, the negative electrode sheet may include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0089] 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.

[0090] 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.

[0091] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0092] In some embodiments, the separator is a separator membrane. The separator membrane can be any known porous structure separator membrane with good chemical and mechanical stability.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0099] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0100] 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.

[0101] 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.

[0102] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0103] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0104] In some implementations, the electrode assembly is a stacked structure.

[0105] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0106] As an example, multiple positive electrode sheets can be set, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0107] As an example, both the positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0108] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0109] As an example, the separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0110] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0111] 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.

[0112] 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.

[0113] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0114] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0115] In some embodiments, the battery can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0116] In some embodiments, the battery can be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing.

[0117] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0118] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0119] In some embodiments, to improve the reliability of a battery cell, a pressure relief mechanism can generally be provided on the wall of the battery cell's casing. In the event of thermal runaway of the battery cell, the pressure inside the battery cell can be released through the pressure relief mechanism.

[0120] A pressure relief mechanism is a component or part that can at least partially open to release internal pressure when the internal pressure of a battery cell reaches a predetermined threshold. This threshold design varies depending on design requirements. The threshold may depend on the materials of one or more of the components in the battery cell: the positive electrode, the negative electrode, the electrolyte, and the separator.

[0121] When the pressure relief mechanism is opened, the high-temperature, high-pressure substances inside the battery cell are discharged outwards from the open portion. This method allows for pressure relief of the battery cell under controlled pressure, thereby preventing potentially more serious accidents.

[0122] The emissions from battery cells mentioned in the embodiments of this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of the separator, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0123] In a typical battery cell, after the electrode assembly is installed inside the casing, the electrode assembly usually rests directly against the wall of the casing where the pressure relief mechanism is located. When the electrode assembly expands and deforms or the wall where the pressure relief mechanism is located is deformed by external force, the wall where the pressure relief mechanism is located will be squeezed against the electrode assembly. The pressure relief mechanism is easily damaged and fails after being impacted by the electrode assembly, which affects the service life of the battery cell.

[0124] In view of this, the present application provides a battery cell by providing a separator between the electrode assembly and the first wall of the housing where a pressure relief mechanism is provided, and providing a clearance space on the separator, thereby avoiding the pressure relief mechanism.

[0125] In such a battery cell, by setting a separator between the first wall and the electrode assembly, the distance between the electrode assembly and the first wall is increased, reducing the risk of the electrode assembly directly impacting the pressure relief mechanism and causing damage to the pressure relief mechanism when the electrode assembly expands and deforms or the first wall is deformed by external force. At the same time, since the separator is provided with a clearance space, the clearance space can avoid the pressure relief mechanism, reducing the risk of the separator directly impacting the pressure relief mechanism and causing damage to the pressure relief mechanism when the electrode assembly expands and deforms or the first wall is deformed by external force, thereby effectively improving the service life of the battery cell.

[0126] The battery cells described in the embodiments of this application are applicable to batteries and electrical devices that use battery cells.

[0127] Electrical equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.

[0128] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0129] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in some embodiments of this application. A battery 100 is disposed inside the vehicle 1000, and the battery 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000.

[0130] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0131] In some embodiments of this application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0132] Please refer to Figure 2, which is an exploded view of a battery 100 provided in some embodiments of this application. The battery 100 includes a battery cell 10 and a housing 20, with the battery cell 10 housed within the housing 20.

[0133] The housing 20 is a component that houses the battery cell 10, providing a space for the battery cell 10. The housing 20 can adopt various structures. In some embodiments, the housing 20 may include a first housing 201 and a second housing 202, which overlap each other to define a space for accommodating the battery cell 10. The first housing 201 and the second housing 202 can have various shapes, such as cuboid or cylindrical. The first housing 201 can be a hollow structure open on one side, and the second housing 202 can also be a hollow structure open on one side, with the open side of the second housing 202 overlapping the open side of the first housing 201, thus forming a housing 20 with a accommodating space. Alternatively, the first housing 201 can be a hollow structure open on one side, and the second housing 202 can be a plate-like structure, with the second housing 202 overlapping the open side of the first housing 201, thus forming a housing 20 with a accommodating space. The first housing 201 and the second housing 202 can be sealed by a sealing element, such as a sealing ring or sealant.

[0134] In battery 100, there can be one or more battery cells 10. If there are multiple battery cells 10, they can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 10 are connected in both series and parallel. Alternatively, multiple battery cells 10 can be first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed manner to form a whole, which is then housed within the housing 20. Another option is that all battery cells 10 can be directly connected in series, parallel, or in a mixed manner, and then the whole consisting of all battery cells 10 is housed within the housing 20.

[0135] Please refer to Figures 3 and 4. Figure 3 is an exploded view of a battery cell 10 provided in some embodiments of this application; Figure 4 is a cross-sectional view of the battery cell 10 shown in Figure 3. The battery cell 10 may include a housing 1 and an electrode assembly 2, the electrode assembly 2 being housed within the housing 1.

[0136] In some embodiments, the housing 1 may include a housing 11 and an end cap 12, the housing 11 having an opening and the end cap 12 closing the opening of the housing 11.

[0137] The housing 11 is a component used to house the electrode assembly 2. The housing 11 can be a hollow structure with an opening at one end, or a hollow structure with openings at both opposite ends. The housing 11 can be in various shapes, such as cylindrical or cuboid. The housing 11 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy.

[0138] End cap 12 is a component that closes the opening of housing 11 to isolate the internal environment of battery cell 10 from the external environment. End cap 12 and housing 11 together define a storage space for accommodating electrode assembly 2, electrolyte, and other components. End cap 12 can be connected to housing 11 by welding or roll sealing to close the opening of housing 11. The shape of end cap 12 can be adapted to the shape of housing 1. For example, if housing 11 is a cuboid structure, end cap 12 can be a rectangular plate structure adapted to housing 1; or if housing 11 is cylindrical, end cap 12 can be a circular plate structure adapted to housing 11. The material of end cap 12 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The materials of end cap 12 and housing 11 can be the same or different.

[0139] In an embodiment where the housing 11 has an opening at one end, one end cap 12 may be provided accordingly. In an embodiment where the housing 11 has openings at both opposite ends, two end caps 12 may be provided accordingly. The two end caps 12 respectively close the two openings of the housing 11, and the two end caps 12 and the housing 11 together define the receiving space.

[0140] In some embodiments, the battery cell 10 may further include an electrode terminal 3 disposed on the housing 1. The electrode terminal 3 is used for electrical connection with the tabs of the electrode assembly 2 to input or output electrical energy of the battery cell 10. The electrode terminal 3 may be disposed on the housing 11 of the housing 1 or on the end cap 12 of the housing 1. The electrode terminal 3 and the tab may be directly connected, for example, by welding the electrode terminal 3 to the tab. The electrode terminal 3 and the tab may also be indirectly connected.

[0141] Please refer to Figure 5, which is a partially enlarged view of the battery cell 10 shown in Figure 4. This application provides a battery cell 10, which includes a housing 1, an electrode assembly 2, a separator 4, and a pressure relief mechanism 131. The housing 1 has a first wall 13, and the pressure relief mechanism 131 is disposed on the first wall 13. The pressure relief mechanism 131 is configured to at least partially open when the battery cell 10 is depressurized. The electrode assembly 2 is housed within the housing 1, and the electrode assembly 2 is disposed opposite to the first wall 13 along a first direction Z. The separator 4 is disposed between the first wall 13 and the electrode assembly 2, and the separator 4 has a clearance space 41. Along the first direction Z, the projection of the pressure relief mechanism 131 is at least partially located within the clearance space 41, and the clearance space 41 is configured to avoid the pressure relief mechanism 131.

[0142] The outer shell 1 can be cylindrical, prismatic, or similar. The first wall portion 13 in the outer shell 1 can be single or multiple. An opening is formed at least at one end of the shell 11 along the first direction Z. In embodiments where the shell 11 has an opening at only one end, the first wall portion 13 can be only the end cap 12, the wall portion of the shell 11 opposite to the end cap 12, or both the end cap 12 and the wall portion of the shell 11 opposite to the end cap 12 can be the first wall portion 13. In embodiments where the shell 11 has openings at both opposite ends, either end cap 12 can be the first wall portion 13, or both end caps 12 can be the first wall portion 13.

[0143] The first direction Z is the arrangement direction of the electrode assembly 2 and the first wall portion 13, and the first direction Z can be parallel to the thickness direction of the first wall portion 13. In embodiments where the outer casing 1 is cylindrical, i.e., the battery cell 10 is a cylindrical battery cell, the first direction Z can be parallel to the axial direction of the outer casing 1. The electrode assembly 2 can be a wound structure or a stacked structure. If the electrode assembly 2 is a wound structure, the first direction Z can be parallel to the extension direction of the winding center line of the electrode assembly 2.

[0144] The electrode assembly 2 may include a main body 21, a first tab 22, and a second tab 23. The first tab 22 and the second tab 23 have opposite polarities. They may be connected to opposite ends of the main body 21 along the first direction Z, or they may be connected to the same end of the main body 21 along the first direction Z. One of the first tab 22 and the second tab 23 is a positive tab, and the other is a negative tab. The main body 21 may be the portion of the electrode assembly 2 corresponding to the area of ​​the electrode sheet coated with an active material layer. The positive tab may be the portion of the positive electrode sheet not coated with a positive active material layer, and the negative tab may be the portion of the negative electrode sheet not coated with a negative active material layer.

[0145] The separator 4 can be an insulating component disposed between the first wall portion 13 and the electrode assembly 2 to achieve insulation isolation between the electrode assembly 2 and the first wall portion 13. The insulating component can be made of materials such as plastic or rubber. As an example, the housing 11 has an opening at only one end, and the end cap 12 is the first wall portion 13. Along the first direction Z, the first electrode tab 22 and the second electrode tab 23 are respectively disposed at both ends of the main body portion 21. The walls of the housing 11 and the end cap 12 opposite each other are provided with electrode terminals 3. The electrode terminals 3 are insulated from the housing 11. The second electrode tab 23 of the electrode assembly 2 is electrically connected to the electrode terminals 3. The first electrode tab 22 of the electrode assembly 2 is electrically connected to the housing 11. A separator 4 is disposed between the first electrode tab 22 and the end cap 12, and the separator 4 insulates and isolates the first electrode tab 22 from the end cap 12.

[0146] The separator 4 can also be a conductive element disposed between the first wall portion 13 and the electrode assembly 2 to achieve electrical connection between the electrode assembly 2 and the first wall portion 13. The conductive element can be a conductive metal, such as copper, iron, aluminum, steel, aluminum alloy, etc. The separator 4 can be directly connected to the electrode assembly 2 or indirectly connected to achieve electrical connection between the separator 4 and the electrode assembly 2; the separator 4 can be directly connected to the first wall portion 13 or indirectly connected to achieve electrical connection between the separator 4 and the first wall portion 13. As an example, as shown in Figure 4, the housing 11 has an opening at only one end, and the end cap 12 is the first wall portion 13. Along the first direction Z, the first electrode tab 22 and the second electrode tab 23 are respectively disposed at both ends of the main body portion 21. The wall portion of the housing 11 opposite to the end cap 12 is provided with electrode terminals 3. The electrode terminals 3 are insulated from the housing 11. The second electrode tab 23 of the electrode assembly 2 is electrically connected to the electrode terminals 3 through the second current collector 6. A separator 4 is provided between the first electrode tab 22 of the electrode assembly 2 and the end cap 12. The separator 4 electrically connects the first electrode tab 22 to the end cap 12.

[0147] The clearance space 41 is a space on the partition 4 used to avoid the pressure relief mechanism 131. The projection of the pressure relief mechanism 131 along the first direction Z can be partially or entirely located within the clearance space 41. The clearance space 41 can be a through hole penetrating both ends of the partition 4 along the first direction Z, or it can be a clearance groove provided on the side of the partition 4 facing the first wall portion 13. In embodiments where the first wall portion 13 and the partition 4 are indirectly connected, for example, the first wall portion 13 and the partition 4 are connected by an intermediate member. The intermediate member can be an annular structure, and the central hole of the intermediate member also serves to avoid the pressure relief mechanism 131, so that the projection of the pressure relief mechanism 131 along the first direction Z is located within the clearance space 41.

[0148] The pressure relief mechanism 131 can be a separate component from the first wall portion 13. The pressure relief mechanism 131 is installed on the first wall portion 13. The pressure relief mechanism 131 can be an explosion-proof plate, a pressure relief valve, etc.; the pressure relief mechanism 131 can also be integrally formed with the first wall portion 13.

[0149] In this embodiment, by providing a separator 4 between the first wall portion 13 and the electrode assembly 2, the distance between the electrode assembly 2 and the first wall portion 13 is increased, reducing the risk of the electrode assembly 2 directly impacting the pressure relief mechanism 131 and causing damage to the pressure relief mechanism 131 when the electrode assembly 2 expands and deforms or the first wall portion 13 is deformed by external force. At the same time, since the separator 4 is provided with a clearance space 41, the clearance space 41 can avoid the pressure relief mechanism 131, reducing the risk of the separator 4 directly impacting the pressure relief mechanism 131 and causing damage to the pressure relief mechanism 131 when the electrode assembly 2 expands and deforms or the first wall portion 13 is deformed by external force, thereby effectively improving the service life of the battery cell 10.

[0150] In some embodiments, please continue to refer to Figure 6, the clearance space 41 is a through hole that passes through both ends of the separator 4 along the first direction Z.

[0151] The clearance space 41 can be a through hole that penetrates both ends of the partition 4 along the first direction Z. The through hole can be a circular hole, a square hole, etc., and the partition 4 can be an annular structure. Alternatively, the clearance space 41 can be a through hole that penetrates both ends of the partition 4 along the first direction Z and extends to the outer peripheral surface of the partition 4 in a direction perpendicular to the first direction Z. The partition 4 can be a U-shaped structure, a semi-annular structure, etc.

[0152] In this embodiment, the clearance space 41 extends through both ends of the separator 4 along the first direction Z. The clearance space 41 can serve as an exhaust channel, which facilitates the flow of emissions from the battery cell 10 located on the side of the separator 4 facing the electrode assembly 2 through the clearance space 41 to the pressure relief mechanism 131.

[0153] In some embodiments, please refer to FIG6, which is a partial view of a battery cell 10 provided in other embodiments of this application. Along the first direction Z, the projection of the separator 4 does not overlap with the projection of the pressure relief mechanism 131. In other words, the orthographic projections of the separator 4 and the pressure relief mechanism 131 in a plane perpendicular to the first direction Z do not overlap.

[0154] The clearance space 41 can be a through hole extending through both ends of the partition 4 along the first direction Z, so that the projection of the partition 4 along the first direction Z does not overlap with the projection of the pressure relief mechanism 131 along the first direction Z. The partition 4 can be a ring-shaped structure, a U-shaped structure, a semi-ring-shaped structure, etc. It can be understood that the projection of the partition 4 along the first direction Z does not overlap with the projection of the pressure relief mechanism 131, so that the projection of the pressure relief mechanism 131 along the first direction Z is completely located within the clearance space 41.

[0155] In this embodiment, the projection of the separator 4 along the first direction Z does not overlap with the projection of the pressure relief mechanism 131 along the first direction Z, further reducing the impact of the separator 4 on the pressure relief mechanism 131, and further reducing the risk of the separator 4 directly impacting the pressure relief mechanism 131 when the electrode assembly 2 expands and deforms or the first wall portion 13 is deformed by external force, thus causing damage to the pressure relief mechanism 131.

[0156] In some embodiments, the pressure relief mechanism 131 includes a weak portion 1311, which is configured to at least partially crack when the battery cell 10 is depressurized, and the projection of the weak portion 1311 is entirely within the clearance space 41 along the first direction Z.

[0157] It is understandable that, along the first direction Z, the projection of the weak part 1311 does not overlap with the projection of the separator 4.

[0158] The weak part 1311 is the part of the pressure relief mechanism 131 that is weaker than other areas. The weak part 1311 can be formed by setting a groove on the pressure relief mechanism 131, or by performing local heat treatment on the pressure relief mechanism 131 to weaken the strength of the local area and form a weak part.

[0159] As an example, in the embodiment shown in FIG6, the pressure relief mechanism 131 is integrally formed with the first wall portion 13. The pressure relief mechanism 131 is provided with a pressure relief groove 136 (not shown in FIG6). The pressure relief mechanism 131 forms a weak portion 1311 at the position where the pressure relief groove 136 is provided. The bottom wall of the pressure relief groove 136 can be the weak portion 1311.

[0160] When the battery cell 10 is depressurized, the depressurization mechanism 131 can crack at the weak point 1311 to at least partially open, thereby releasing the pressure inside the battery cell 10. The projection of the weak point 1311 is located within the clearance space 41, which can effectively reduce the impact of the separator 4 on the weak point 1311 and reduce the risk of the weak point 1311 cracking prematurely due to impact.

[0161] In some embodiments, please refer to Figures 7-10. Figure 7 is an exploded view of a battery cell 10 (the first portion 441 is connected to the outer peripheral surface 433 of the ring) provided in some embodiments of this application; Figure 8 is a cross-sectional view of the battery cell 10 shown in Figure 7; Figure 9 is a partially enlarged view of the battery cell 10 shown in Figure 8; and Figure 10 is an isometric view of the separator 4 shown in Figure 9. The housing 1 includes a sidewall 14 surrounding a first wall portion 13, which is disposed at one end of the sidewall 14 along a first direction Z. An electrode assembly 2 has a first tab 22 formed at one end along the first direction Z near the first wall portion 13. A first flow channel 7 is formed between the first tab 22 and the sidewall 14. The separator 4 directly or indirectly abuts against the first tab 22 along the first direction Z. The separator 4 is provided with a second flow channel 42, which connects the first flow channel 7 and the clearance space 41.

[0162] The sidewall 14 can be cylindrical, making the battery cell 10 a cylindrical battery cell; the sidewall 14 can also be cuboid, making the battery cell 10 a square battery cell 10 or a blade battery cell 10. The sidewall 14 and the first wall portion 13 can be integrally formed, and the sidewall 14 and the first wall portion 13 together constitute the housing 11. The end of the sidewall 14 away from the first wall portion 13 along the first direction Z forms an opening in the housing 11; the sidewall 14 and the first wall portion 13 can also be separate, with the first wall portion 13 serving as an end cap 12. The end of the sidewall 14 near the first wall portion 13 along the first direction Z forms an opening in the housing 11. The first wall portion 13 and the sidewall 14 can be connected by welding, bonding, rolling, or other methods.

[0163] The first flow channel 7 can be a gap formed between the outer peripheral surface of the electrode tab and the inner peripheral surface 141 of the sidewall. After the electrode assembly 2 is installed in the housing 1, a gap communicating with the first flow channel 7 can also be formed between the outer peripheral surface of the main body 21 and the inner peripheral surface 141 of the sidewall, allowing emissions generated by thermal runaway of the electrode assembly 2 to enter the first flow channel 7 through this gap. Of course, if the outer periphery of the main body 21 is covered with an insulating film, a gap communicating with the first flow channel can be formed between the outer peripheral surface of the insulating film and the inner peripheral surface 141 of the sidewall. The inner peripheral surface 141 of the sidewall is the surface of the sidewall 14 facing the electrode assembly 2, and the inner peripheral surface can extend circumferentially around the opening of the housing 11. It can be understood that if the sidewall 14 is cylindrical, the inner peripheral surface 141 of the sidewall is cylindrical; if the sidewall 14 is cuboid, the inner peripheral surface 141 of the sidewall is cuboid.

[0164] The separator 4 can directly abut against the first electrode 22, or indirectly abut against the first electrode 22 through an intermediate component. The intermediate component can be a conductive component or an insulating component. There can be one or more second flow channels 42 on the separator 4. If there are multiple second flow channels 42, they can be evenly distributed along the circumference of the separator 4, or non-uniformly distributed along the circumference of the separator 4. The circumference of the separator 4 can be the circumference of a circle surrounding a centerline extending along the first direction Z.

[0165] The second guide channel can be a through hole that penetrates the inner and outer peripheral surfaces of the separator 4 radially, or it can be a notch groove that penetrates the inner and outer peripheral surfaces of the separator 4 radially and extends along the first direction Z to one end of the end face of the separator 4.

[0166] In this embodiment, a second flow channel 42 is provided on the separator 4, and the avoidance space 41 and the first flow channel 7 are connected through the second flow channel 42. When the battery cell 10 thermally runs away, the discharge located on the side of the electrode assembly 2 flows to the first flow channel 7. The discharge can then enter the avoidance space 41 through the second flow channel 42 on the separator 4, so that the discharge can quickly reach the vicinity of the pressure relief mechanism 131, so that the pressure relief mechanism 131 can open and relieve pressure in time, reducing the risk of battery cell 10 explosion and fire, and effectively improving the reliability of battery cell 10.

[0167] In some embodiments, please continue to refer to Figures 9-11, where Figure 11 is a cross-sectional view of the separator 4 shown in Figure 10. The electrode assembly 2 has a first tab 22 formed at one end near the first wall portion 13 along the first direction Z. The separator 4 includes a ring body 43 and a plurality of protrusions 44. Along the first direction Z, the ring body 43 has opposing first surfaces 431 and second surfaces 432, with a clearance space 41 extending through the first surfaces 431 and 432. The plurality of protrusions 44 are spaced apart along the circumferential direction X of the ring body 43. Each protrusion 44 at least partially protrudes from the first surface 431, and a second flow channel 42 is formed between the portions of two adjacent protrusions 44 protruding from the first surface 431, communicating with the clearance space 41. Along the first direction Z, one of the ring body 43 and the protrusions 44 directly or indirectly abuts against the first tab 22, and the first wall portion 13 directly or indirectly abuts against the other of the ring body 43 and the protrusions 44.

[0168] It is understood that in the embodiment where a first flow channel 7 is formed between the first tab 22 and the side wall 14 of the outer shell 1, a second flow channel 42 is formed between two adjacent protrusions 44 to connect the first flow channel 7 with the clearance space 41.

[0169] The ring 43 has a ring-shaped structure, such as a rectangular ring or a circular ring. A clearance space 41 extends along the first direction Z through both ends of the separator 4 along the first direction Z. A portion of the clearance space 41 is located within the ring 43, and another portion is located in the central region of multiple protrusions 44. The protrusions 44 in the separator 4 can be two, three, four, five, or more. The multiple protrusions 44 can be evenly distributed or non-uniformly distributed along the circumferential direction X of the ring, which is the circumferential direction of the separator 4. A second flow channel 42 is formed between the portions of two adjacent protrusions 44 that protrude from the first surface 431. This second flow channel 42 can be a notch or groove provided on the separator 4. In the separator 4, the number of second flow channels 42 is equal to the number of protrusions 44, and the second flow channels 42 and protrusions 44 are alternately arranged along the circumferential direction X of the ring.

[0170] The first surface 431 and the second surface 432 can be the end faces of the two ends of the ring 43 in the thickness direction, and the thickness direction of the ring 43 is parallel to the first direction Z. The protrusion 44 can be entirely protruding from the first surface 431, such that the protrusion 44 protrudes from the first surface 431 in a direction away from the second surface 432; or the protrusion 44 can only be partially protruding from the first surface 431, for example, the protrusion 44 is connected to the outer peripheral surface 433 or the inner peripheral surface of the ring, and the protrusion 44 is partially located on the side of the first surface 431 away from the second surface 432, such that a part of the protrusion 44 protrudes from the first surface 431. The protrusion 44 and the ring 43 can be separately provided and connected, for example, the protrusion 44 and the ring 43 can be bonded, welded, etc.; or the protrusion 44 and the ring 43 can be integrally formed, so that the protrusion 44 and the ring 43 are an integrally formed structure.

[0171] The ring 43 may directly or indirectly abut against the first tab 22, the first wall portion 13 may directly or indirectly abut against the protrusion 44, the first surface 431 may face the first wall portion 13, and the second surface 432 may face the electrode assembly 2, that is, the first surface 431 is farther away from the electrode assembly 2 along the first direction Z than the second surface 432; or the protrusion 44 may directly or indirectly abut against the first tab 22, the first wall portion 13 may directly or indirectly abut against the ring 43, the first surface 431 may face the electrode assembly 2, and the second surface 432 may face the first wall portion 13, that is, the first surface 431 is closer to the electrode assembly 2 along the first direction Z than the second surface 432.

[0172] In this embodiment, since one of the ring body 43 and the protrusion 44 directly or indirectly abuts against the first electrode tab 22, and the first wall portion 13 directly or indirectly abuts against the other of the ring body 43 and the protrusion 44, the intermediate member is supported between the first electrode tab 22 and the first wall portion 13. The intermediate member can restrict the electrode assembly 2 from moving towards the first wall portion 13, reducing the risk of the electrode assembly 2 moving along the first direction Z within the housing 1. Since the second flow channel 42 between two adjacent protrusions 44 is connected to the clearance space 41 of the separator 4, when the battery cell 10 experiences thermal runaway, the discharge located on the side of the electrode assembly 2 can enter the clearance space 41 through the second flow channel 42 between two adjacent protrusions 44, so that the discharge can quickly reach the vicinity of the pressure relief mechanism 131, allowing the pressure relief mechanism 131 to release pressure in a timely manner, reducing the risk of the battery cell 10 exploding or catching fire, and effectively improving the reliability of the battery cell 10. In other words, the second flow channel 42 and the clearance space 41 can form a channel for the discharge between the electrode assembly 2 and the first wall portion 13, so that the discharge located on the side of the electrode assembly 2 can quickly flow to the pressure relief mechanism 131.

[0173] In some embodiments, the battery cell 10 may include a first current collector 5 disposed between the separator 4 and the first tab 22 along the first direction Z. The first current collector 5 is electrically connected to the separator 4 and the first tab 22, and the first wall portion 13 is electrically connected to the separator 4. Along the first direction Z, the protrusion 44 directly abuts against the first current collector 5, the first current collector 5 directly abuts against the first tab 22, and the first wall portion 13 directly abuts against the ring body 43.

[0174] The first current collector 5 and the separator 4 are conductive components disposed between the electrode assembly 2 and the first wall portion 13. The first current collector 5 is electrically connected to the separator 4 and the first tab 22, and the first wall portion 13 is electrically connected to the separator 4, thereby realizing the electrical connection between the first wall portion 13 and the first tab 22, making the first wall portion 13 an output electrode in the battery cell 10. If the first tab 22 is a positive tab, the first wall portion 13 is a positive output electrode; if the first tab 22 is a negative tab, the first wall portion 13 is a negative output electrode.

[0175] The protrusion 44 directly abuts against the first current collector 5, achieving an electrical connection between the separator 4 and the first current collector 5; the first current collector 5 directly abuts against the first electrode tab 22, achieving an electrical connection between the first current collector 5 and the first electrode tab 22; the first wall portion 13 directly abuts against the ring body 43, achieving an electrical connection between the first wall portion 13 and the separator 4. It can be understood that, in this embodiment, along the first direction Z, the first surface 431 is closer to the electrode assembly 2 than the second surface 432.

[0176] It should be noted that in the embodiments of this application, "direct contact" means that the two components are in direct contact without any intermediate parts between them. This does not limit the two components to simply maintaining contact without any other connection. In other words, after the two components are in direct contact, other connection methods can be used to fix the two components. For example, the protrusion 44 directly abuts against the first current collector 5, and the protrusion 44 is welded to the first current collector 5; the first current collector 5 directly abuts against the first electrode 22, and the first current collector 5 is welded to the first electrode 22; the first wall portion 13 directly abuts against the ring body 43, and the first wall portion 13 is welded to the ring body 43.

[0177] As an example, as shown in Figure 8, the housing 11 has an opening at only one end, and the end cap 12 is the first wall portion 13. Along the first direction Z, the first electrode tab 22 and the second electrode tab 23 are respectively disposed at both ends of the main body portion 21. The wall portion of the housing 11 opposite to the end cap 12 is provided with electrode terminals 3. The electrode terminals 3 are insulated from the housing 11. The second electrode tab 23 of the electrode assembly 2 is electrically connected to the electrode terminals 3 through the second current collector 6. The first current collector 5 is electrically connected to the separator 4 and the first electrode tab 22. The separator 4 is electrically connected to the first current collector 5 and the end cap 12. It can be understood that the electrode terminal 3 is one output terminal of the battery cell 10, and the first wall portion 13 is the other output terminal of the battery cell 10.

[0178] In this embodiment, by providing a first current collector 5 between the separator 4 and the first tab 22, the electrical connection between the first tab 22 and the separator 4 can be achieved, reducing the difficulty of the electrical connection between the first tab 22 and the separator 4. The protrusion 44 directly abuts against the first current collector 5, and the first wall portion 13 directly abuts against the ring body 43, so that the second flow channel 42 is formed on the side of the separator 4 facing the electrode assembly 2, so that the emissions located on the side of the electrode assembly 2 during thermal runaway of the battery cell 10 can enter the second flow channel 42 more quickly.

[0179] In some embodiments, please refer to FIG12, which is a view of the separator 4 shown in FIG11 from direction A. The ring body 43 is welded to the first wall portion 13 (shown in FIG9) to form a first solder area 45, and at least one protrusion 44 is welded to the first current collector 5 (shown in FIG9) to form a second solder area 46. Along the first direction Z, the projection of the first solder area 45 and the projection of the second solder area 46 do not overlap.

[0180] The first solder mark area 45 is the area where the ring body 43 and the first wall portion 13 are welded together to form a solder mark. The first solder mark area 45 can be the part where the ring body 43 and the first wall portion 13 are welded and fused together. There can be one or more first solder mark areas 45.

[0181] The second solder mark area 46 is the area where the protrusion 44 and the first current collector 5 are welded together to form a solder mark. The second solder mark area 46 can be the part where the protrusion 44 and the first current collector 5 are welded together. It can be that one protrusion 44 is welded to the first current collector 5 to form one second solder mark area 46, or multiple protrusions 44 are welded to the first current collector 5 to form multiple second solder mark areas 46.

[0182] The projection of the first solder area 45 along the first direction Z can be located at the position corresponding to the separator 4 and the second flow channel 42, and the projection of the first solder area 45 along the first direction Z can be located at the position corresponding to the separator 4 and the protrusion 44.

[0183] As an example, as shown in Figure 12, there are multiple first solder areas 45 and second solder areas 46. Along the circumferential direction X of the ring, the first solder areas 45 and second solder areas 46 are alternately arranged. The projection of the first solder area 45 along the first direction Z is located at the position corresponding to the separator 4 and the second guide channel 42.

[0184] In this embodiment, the projection of the first solder area 45 along the first direction Z does not overlap with the projection of the second solder area 46 along the first direction Z, which can reduce the mutual interference between the first solder area 45 and the second solder area 46, and reduce the risk of poor soldering when the ring body 43 is welded to the first wall portion 13 or the protrusion 44 is welded to the first current collector 5.

[0185] In some embodiments, referring to Figures 10 and 11, the protrusion 44 includes a first portion 441, which includes a first bending portion 4411 and a first connecting portion 4412. The first bending portion 4411 is connected to the outer peripheral surface 433 of the ring body, and the first connecting portion 4412 is connected to the first bending portion 4411. The first connecting portion 4412 is at least partially located on the side of the first surface 431 opposite to the second surface 432.

[0186] The protrusion 44 may include only the first portion 441, or it may include portions other than the first portion 441. The outer peripheral surface 433 of the ring body connects the first surface 431 and the second surface 432. The first connecting portion 4412 is at least partially located on the side of the first surface 431 facing away from the second surface 432, such that the first surface 431 is located between at least a portion of the first connecting portion 4412 and the second surface 432 along the first direction Z. The first connecting portion 4412 may be completely located on the side of the first surface 431 facing away from the second surface 432, such that the first connecting portion 4412 and the ring body 43 are arranged along the first direction Z; the first connecting portion 4412 may also be only partially located on the side of the first surface 431 facing away from the second surface 432. Along the first direction Z, the first connecting portion 4412 and the first surface 431 may be in contact or have a gap.

[0187] The first connecting portion 4412 can be a single-layer structure or a multi-layer structure formed by at least one bend. As an example, in the embodiment shown in FIG10, the first connecting portion 4412 is a single-layer structure.

[0188] The first bend 4411 may be provided with a process notch to reduce the force required when bending the first bend 4411.

[0189] In this embodiment, the first part 441 is a structure connected to the outer peripheral surface 433 of the ring body and partially bent on the side of the first surface 431 away from the second surface 432. The structure of the first part 441 is simple, thereby reducing the molding difficulty of the protrusion 44. In addition, since the first bent part 4411 is connected to the outer peripheral surface 433 of the ring body, the first bent part 4411 does not occupy the internal space of the ring body 43, which can increase the clearance space 41, improve the clearance space 41's ability to avoid the pressure relief mechanism 131 and the guiding ability for the flow of discharged materials.

[0190] In some embodiments, please continue to refer to Figures 10 and 11, along the first direction Z, the first connecting portion 4412 and the first surface 431 are spaced apart.

[0191] A first gap 4413 is formed between the first connecting part 4412 and the first surface 431, so that the first connecting part 4412 does not contact the first surface 431.

[0192] In this embodiment, the first connecting portion 4412 and the first surface 431 are spaced apart along the first direction Z. The separator 4 acts as a buffer between the first wall portion 13 and the electrode assembly 2 to absorb the impact force on the first wall portion 13 and reduce the risk of damage to the electrode assembly 2 caused by external impacts to the first wall portion 13. In addition, the first gap 4413 formed between the first connecting portion 4412 and the first surface 431 can connect two adjacent second guide channels 42. When the discharge located on the side of the electrode assembly 2 flows into one of the second guide channels 42, the discharge can flow through the first gap 4413 to the other adjacent second guide channel 42, allowing the discharge to enter the clearance space 41 more quickly.

[0193] In some embodiments, please refer to Figures 13-16. Figure 13 is a partial view of a battery cell 10 (the protrusion 44 includes a first portion 441, which is connected to the outer peripheral surface 433 of the ring body) provided in some embodiments of this application; Figure 14 is an isometric view of the separator 4 shown in Figure 13; Figure 15 is a partial view of a battery cell 10 (the protrusion 44 includes a first portion 441, which is connected to the outer peripheral surface 433 of the ring body) provided in other embodiments of this application; Figure 16 is an isometric view of the separator 4 shown in Figure 15. The first connecting portion 4412 includes a second bending portion 44121 and a plurality of first stacked portions 44122. The plurality of first stacked portions 44122 are located on the side of the first surface 431 facing away from the second surface 432, and the plurality of first stacked portions 44122 are arranged along the first direction Z. The second bending portion 44121 connects two adjacent first stacked portions 44122.

[0194] The first stacked portions 44122 in the first connecting portion 4412 can be two, three, four, five, or more. Two adjacent first stacked portions 44122 can be in direct contact or have a gap. Two adjacent first stacked portions 44122 are connected by a second bend 44121. In the first connecting portion 4412, there is one more first stacked portion 44122 than second bend 44121. The first bend 4411 can be connected to any one of the first stacked portions 44122, or to any one of the first bend 4411. Because the first connecting portion 4412 includes multiple first stacked portions 44122, the first connecting portion 4412 has a multi-layered structure.

[0195] The first part 441 can be made of metal or insulating material. In an embodiment where the protrusion 44 includes only the first part 441 and the protrusion 44 directly abuts against the first current collector 5, the first part 441 can be made of metal. It can be the first stacked part 44122 of the first connecting part 4412 that is farthest from the ring body 43 that abuts against the first current collector 5 to achieve electrical connection between the separator 4 and the first current collector 5.

[0196] The second bend 44121 may be provided with a process notch to reduce the force required when bending the second bend 44121.

[0197] In this embodiment, there are multiple first stacked portions 44122 in the first connecting portion 4412. The multiple first stacked portions 44122 are arranged along the first direction Z on the side of the first surface 431 away from the second surface 432, and two adjacent first stacked portions 44122 are connected by the second bending portion 44121. This structure can increase the height of the protrusion 44 protruding from the first surface 431, thereby increasing the size of the second guide channel 42 in the first direction Z and improving the smoothness of the flow of the discharge in the second guide channel 42.

[0198] In some embodiments, referring to Figures 14 and 16, the gap between two adjacent first stacked portions 44122 is set along the first direction Z.

[0199] Two adjacent first-layer stacks 44122 are spaced apart along the first direction Z, and a second gap 4414 is formed between the two adjacent first-layer stacks 44122, so that the two connected first-layer stacks 44122 do not contact each other.

[0200] In this embodiment, two adjacent first stacked portions 44122 are spaced apart along the first direction Z, forming a second gap 4414 between them. This allows the first connecting portion 4412 to act as a buffer between the first wall portion 13 and the electrode assembly 2, absorbing the impact force on the first wall portion 13 and reducing the risk of damage to the electrode assembly 2 caused by external impacts. Furthermore, the second gap 4414 formed between two adjacent first stacked portions 44122 can connect two adjacent second flow channels 42. When the discharge material located on the side of the electrode assembly 2 flows concentratedly into one of the second flow channels 42, the discharge material can flow through the second gap 4414 to the other adjacent second flow channel 42, allowing the discharge material to enter the clearance space 41 more quickly.

[0201] In some embodiments, referring to FIG14, along the first direction Z, a first stacked portion 44122 closest to the first surface 431 is connected to the first bent portion 4411.

[0202] As an example, there are two first stacked portions 44122 in the first connecting portion 4412, and one second bending portion 44121. The first bending portion 4411, a first stacked portion 44122 near the ring body 43, the second bending portion 44121, and a first stacked portion 44122 away from the ring body 43 are connected in sequence.

[0203] In some embodiments, referring to FIG16, along the first direction Z, a first stack portion 44122 that is furthest from the first surface 431 is connected to the first bend portion 4411.

[0204] As an example, there are two first stacked portions 44122 in the first connecting portion 4412, and one second bending portion 44121. The first bending portion 4411, a first stacked portion 44122 away from the ring body 43, the second bending portion 44121, and a first stacked portion 44122 close to the ring body 43 are arranged in sequence.

[0205] In some embodiments, as shown in Figures 14 and 16, the first part 441 is integrally bent from a sheet metal.

[0206] In this embodiment, the first part 441 and the ring 43 can be integrally formed; the first part 441 and the ring 43 can also be separately set and connected, such as by welding. By integrally bending the sheet metal, the first connecting part 4412 and the first bending part 4411 can be formed accordingly. After the first connecting part 4412 is bent multiple times, multiple first stacked parts 44122 can be formed.

[0207] In this embodiment, the first part 441 is integrally bent from a sheet metal. This structure of the first part 441 has high structural stability and is easy to form.

[0208] In some embodiments, please refer to Figures 17-20. Figure 17 is a partial view of a battery cell 10 (the protrusion 44 includes a first portion 441 and a second portion 442, the first portion 441 is connected to the outer peripheral surface 433 of the ring body, and the second portion 442 is connected to the inner peripheral surface 434 of the ring body) provided in some embodiments of this application; Figure 18 is an isometric view of the separator 4 shown in Figure 17; Figure 19 is a partial view of a battery cell 10 (the protrusion 44 includes a first portion 441 and a second portion 442, the first portion 441 is connected to the outer peripheral surface 433 of the ring body, and the second portion 442 is connected to the inner peripheral surface 434 of the ring body) provided in other embodiments of this application; Figure 20 is an isometric view of the separator 4 shown in Figure 19. The protrusion 44 includes a second portion 442, which includes a third bend 4421 and a second connecting portion 4422. The third bend 4421 is connected to the inner circumferential surface 434 of the ring body, and the second connecting portion 4422 is connected to the third bend 4421. The second connecting portion 4422 is at least partially located on the side of the first surface 431 opposite to the second surface 432. The second connecting portion 4422 and the first connecting portion 4412 are arranged along a first direction Z. Specifically, the first connecting portion 4412 is closer to the first surface 431 along the first direction Z than the second connecting portion 4422; or, the second connecting portion 4422 is closer to the first surface 431 along the first direction Z than the first connecting portion 4412.

[0209] In this embodiment, the protrusion 44 includes a first portion 441 and a second portion 442. The first portion 441 is connected to the outer peripheral surface 433 of the ring body, and the second portion 442 is connected to the inner peripheral surface 434 of the ring body. The first connecting portion 4412 can be a single-layer structure or a multi-layer structure formed by at least one bend.

[0210] In the embodiments shown in Figures 17 and 18, both the first connecting portion 4412 and the second connecting portion 4422 are single-layer structures. The first connecting portion 4412 is closer to the first surface 431 than the second connecting portion 4422, that is, the first connecting portion 4412 is located between the second connecting portion 4422 and the ring body 43. The second connecting portion 4422 directly abuts against the first current collecting member 5, and the first wall portion 13 directly abuts against the ring body 43.

[0211] In the embodiments shown in Figures 19 and 20, both the first connecting portion 4412 and the second connecting portion 4422 are single-layer structures. The second connecting portion 4422 is closer to the first surface 431 along the first direction Z than the first connecting portion 4412, that is, the second connecting portion 4422 is located between the first connecting portion 4412 and the ring body 43. The first connecting portion 4412 directly abuts against the first current collecting member 5, and the first wall portion 13 directly abuts against the ring body 43.

[0212] In this embodiment, the second connecting portion 4422 of the second portion 442 and the first connecting portion 4412 of the first portion 441 are arranged along the first direction Z, which can increase the height of the protrusion 44 protruding from the first surface 431, thereby increasing the size of the second guide channel 42 in the first direction Z and improving the smoothness of the discharge flowing in the second guide channel 42.

[0213] In some embodiments, please refer to Figures 21 and 22. Figure 21 is a partial view of a battery cell 10 (with a first portion 441 connected to the inner circumferential surface 434 of the ring body) provided in some embodiments of this application; Figure 22 is an isometric view of the separator 4 shown in Figure 21. The protrusion 44 includes a second portion 442, which includes a third bend 4421 and a second connecting portion 4422. The third bend 4421 is connected to the inner circumferential surface 434 of the ring body, and the second connecting portion 4422 is connected to the third bend 4421. The second connecting portion 4422 is at least partially located on the side of the first surface 431 opposite to the second surface 432.

[0214] The protrusion 44 may include only the second portion 442, or it may include other portions besides the second portion 442. For example, the protrusion 44 may also include the first portion 441 in the aforementioned embodiment. The inner circumferential surface 434 of the ring body connects the first surface 431 and the second surface 432. The second connecting portion 4422 is at least partially located on the side of the first surface 431 away from the second surface 432, such that the first surface 431 is located between at least a portion of the second connecting portion 4422 and the second surface 432 along the first direction Z. The second connecting portion 4422 may be completely located on the side of the first surface 431 away from the second surface 432, such that the second connecting portion 4422 and the ring body 43 are arranged along the first direction Z; the second connecting portion 4422 may also be only partially located on the side of the first surface 431 away from the second surface 432. Along the first direction Z, the second connecting portion 4422 and the first surface 431 may be in contact or there may be a gap.

[0215] The second connecting portion 4422 can be a single-layer structure or a multi-layer structure formed by at least one bend. As an example, in the embodiments shown in Figures 21 and 22, the second connecting portion 4422 is a single-layer structure.

[0216] The third bend 4421 may be provided with a process notch to reduce the force required when bending the third bend 4421.

[0217] In this embodiment, the second part 442 is a structure connected to the inner circumferential surface 434 of the ring body and partially bent on the side of the first surface 431 away from the second surface 432. The structure of the second part 442 is simple, thereby reducing the molding difficulty of the protrusion 44. In addition, since the third bent part 4421 is connected to the inner circumferential surface 434 of the ring body, the dimension of the third bent part 4421 along the circumferential direction X of the ring body can be reduced, thus reducing the material used for the third bent part 4421.

[0218] In some embodiments, the second connecting portion 4422 is spaced apart from the first surface 431 along the first direction Z.

[0219] A third gap 4423 is formed between the second connecting part 4422 and the first surface 431, so that the second connecting part 4422 does not contact the first surface 431.

[0220] In this embodiment, the second connecting portion 4422 and the first surface 431 are spaced apart along the first direction Z. The separator 4 acts as a buffer between the first wall portion 13 and the electrode assembly 2 to absorb the impact force on the first wall portion 13 and reduce the risk of damage to the electrode assembly 2 caused by external impacts to the first wall portion 13. In addition, a third gap 4423 can be formed between the second connecting portion 4422 and the first surface 431 to connect two adjacent second guide channels 42. When the discharge located on the side of the electrode assembly 2 flows into a certain second guide channel 42, the discharge can flow through the third gap 4423 to the other adjacent second guide channel 42, so that the discharge can enter the clearance space 41 more quickly.

[0221] In some embodiments, please refer to Figures 23-26. Figure 23 is a partial view of a battery cell 10 (the protrusion 44 includes a second portion 442, which is connected to the inner circumferential surface 434 of the ring body) provided in other embodiments of this application; Figure 24 is an isometric view of the separator 4 shown in Figure 23; Figure 25 is a partial view of a battery cell 10 (the protrusion 44 includes a second portion 442, which is connected to the inner circumferential surface 434 of the ring body) provided in yet another embodiment of this application; Figure 26 is an isometric view of the separator 4 shown in Figure 25. The second connecting portion 4422 includes a fourth bending portion 44221 and a plurality of second stacked portions 44222. The plurality of second stacked portions are located on the side of the first surface 431 opposite to the second surface 432, and the plurality of second stacked portions 44222 are arranged along the first direction Z. The fourth bending portion 44221 connects two adjacent second stacked portions 44222.

[0222] The second stacked portions 44222 in the second connecting portion 4422 can be two, three, four, five, or more. Two adjacent second stacked portions 44222 can be in direct contact or have a gap. Two adjacent second stacked portions 44222 are connected by a fourth bend 44221; in the second connecting portion 4422, there is one more second stacked portion 44222 than fourth bend 44221. The third bend 4421 can be connected to any one of the second stacked portions 44222 or any one of the fourth bend 44221. Because the second connecting portion 4422 includes multiple second stacked portions 44222, it has a multi-layered structure.

[0223] The second part 442 can be made of metal or insulating material. In an embodiment where the protrusion 44 includes only the second part 442 and the protrusion 44 directly abuts against the first current collector 5, the second part 442 can be made of metal. It can be the second stacked part 44222 furthest from the ring body 43 in the second connecting part 4422 abuts against the first current collector 5 to achieve electrical connection between the separator 4 and the first current collector 5.

[0224] The fourth bend 44221 may be provided with a process notch to reduce the force required when bending the fourth bend 44221.

[0225] In this embodiment, there are multiple second stacked portions 44222 in the second connecting portion 4422. The multiple second stacked portions 44222 are arranged along the first direction Z on the side of the first surface 431 away from the second surface 432, and two adjacent second stacked portions 44222 are connected by the fourth bending portion 44221. This structure can increase the height of the protrusion 44 protruding from the first surface 431, thereby increasing the size of the second guide channel 42 in the first direction Z and improving the smoothness of the flow of the discharge in the second guide channel 42.

[0226] In some embodiments, referring to Figures 24 and 26, the gap between two adjacent second layer stacks 44222 is set along the first direction Z.

[0227] Two adjacent second-layer stacks 44222 are spaced apart along the first direction Z, and a fourth gap 4424 is formed between two adjacent second-layer stacks 44222, so that the two connected second-layer stacks 44222 do not contact each other.

[0228] In this embodiment, two adjacent second stacked portions 44222 are spaced apart along the first direction Z, forming a fourth gap 4424 between them. This allows the second connecting portion 4422 to act as a buffer between the first wall portion 13 and the electrode assembly 2, absorbing the impact force on the first wall portion 13 and reducing the risk of damage to the electrode assembly 2 caused by external impacts. Furthermore, the fourth gap 4424 formed between two adjacent second stacked portions 44222 can connect two adjacent second guide channels 42. When the discharge material located on the side of the electrode assembly 2 flows concentratedly into one second guide channel 42, the discharge material can flow through the fourth gap 4424 to the other adjacent second guide channel 42, allowing the discharge material to enter the clearance space 41 more quickly.

[0229] In some embodiments, referring to FIG24, along the first direction Z, a second stack 44222 closest to the first surface 431 is connected to the third bend 4421.

[0230] As an example, there are two second stacked portions 44222 in the second connecting portion 4422, one fourth bending portion 44221, and the third bending portion 4421, a second stacked portion 44222 near the ring body 43, the fourth bending portion 44221 and a second stacked portion 44222 away from the ring body 43 are connected in sequence.

[0231] In some embodiments, referring to FIG26, along the first direction Z, a second stack 44222 that is furthest from the first surface 431 is connected to the third bend 4421.

[0232] As an example, there are two second stacked portions 44222 in the second connecting portion 4422, one fourth bending portion 44221, and the third bending portion 4421, a second stacked portion 44222 away from the ring body 43, the fourth bending portion 44221 and a second stacked portion 44222 close to the ring body 43 are arranged in sequence.

[0233] In some embodiments, the second part 442 is integrally bent from a sheet material.

[0234] In this embodiment, the second part 442 and the ring 43 can be integrally formed; the second part 442 and the ring 43 can also be separately set and connected, such as by welding. By integrally bending the sheet metal, the second connecting part 4422 and the third bending part 4421 can be formed accordingly. After the second connecting part 4422 is bent multiple times, multiple second stacked parts 44222 can be formed.

[0235] In this embodiment, the second part 442 is integrally bent from a sheet metal. This structure of the second part 442 has high structural stability and is easy to form.

[0236] In some embodiments, please continue to refer to FIG25, along the first direction Z, the minimum thickness of the ring 43 is D, D≥0.3mm.

[0237] The thickness of the ring 43 is the minimum distance between the first surface 431 and the second surface 432.

[0238] D can be any one of the following values: 0.3mm, 0.5mm, 0.8mm, 1mm, 1.3mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.5mm, 2.8mm, 3mm, 3.3mm, 3.5mm, 3.8mm, 4mm, 4.3mm, 4.5mm, 4.8mm, 5mm, or a range between any two.

[0239] In this embodiment, D≥0.3mm, so that the ring 43 has sufficient thickness. On the one hand, the ring 43 has sufficient structural strength, and on the other hand, there is a sufficiently large distance between the electrode assembly 2 and the first wall 13. This further reduces the risk of the electrode assembly 2 directly impacting the pressure relief mechanism 131 and causing damage to the pressure relief mechanism 131 when the electrode assembly 2 expands and deforms or the first wall 13 is deformed by external force.

[0240] In some embodiments, please continue to refer to Figures 25 and 26. The separator 4 is electrically connected to the first wall portion 13 and the first electrode 22. Along the circumferential direction X of the ring body, the sum of the maximum dimensions of all protrusions 44 is A1, and the sum of the maximum dimensions of all second guide channels 42 is A2. 0.1≤A1 / (A1+A2)≤0.8.

[0241] The separator 4 can be directly or indirectly connected to the first wall portion 13 to achieve electrical connection between the separator 4 and the first wall portion 13. The separator 4 can also be directly or indirectly connected to the first electrode tab 22 to achieve electrical connection between the separator 4 and the first electrode tab 22.

[0242] Along the circumferential direction X of the ring body, the maximum dimensions of each protrusion 44 can be equal or unequal, and the maximum dimensions of each second guide channel 42 can be equal or partially equal.

[0243] As an example, the ring body 43 is a circular ring structure. Along the circumferential direction X of the ring body, the protrusions 44 extend along an arc trajectory. The maximum size of all protrusions 44 is equal, and the maximum size of the protrusion 44 is the maximum arc length of the protrusion 44. The maximum size of the second flow channel 42 is the maximum arc length of the second flow channel 42. The maximum size of the protrusion 44 is a1, the maximum size of the second flow channel 42 is a2, and the number of protrusions 44 and the number of second flow channels 42 are both n. A1 = a1 × n, A2 = a2 × n, A1 / (A1 + A2) = a1 / (a1 + a2).

[0244] A1 / (A1+A2) can take any one of the following point values ​​or any range between two values: 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, and 0.8.

[0245] A1 / (A1+A2)≥0.1 ensures that the proportion of the dimensions of all protrusions 44 in the circumferential X direction of the ring body is not too small, and that all protrusions 44 as a whole have sufficient contact area with the parts they directly abut against, so as to achieve stable flow; A1 / (A1+A2)≤0.8 ensures that the proportion of the dimensions of all second flow channels 42 in the circumferential X direction of the ring body is not too small, and that the discharge material on the side of the electrode assembly 2 can quickly enter the clearance space 41, so that the pressure relief mechanism 131 can open and relieve pressure more promptly.

[0246] In some embodiments, the separator 4 is electrically connected to the first wall portion 13 and the electrode assembly 2.

[0247] It is understood that the separator 4 is a conductive component. The separator 4 can directly abut against the first wall portion 13 or indirectly abut against it to achieve electrical connection between the separator 4 and the first wall portion 13. The separator 4 can directly abut against the electrode assembly 2 or indirectly abut against the electrode assembly 2 to achieve electrical connection between the separator 4 and the electrode assembly 2.

[0248] In this embodiment, the separator 4 not only separates the first wall portion 13 and the electrode assembly 2, but also electrically connects the first wall portion 13 and the electrode assembly 2.

[0249] In some embodiments, the battery cell 10 includes a first current collector 5, which is disposed between the separator 4 and the electrode assembly 2 along a first direction Z. The first current collector 5 is electrically connected to the separator 4 and the electrode assembly 2. Along the first direction Z, the projection of the first current collector 5 covers the avoidance space 41.

[0250] It is understandable that the electrode assembly 2 and the first wall portion 13 are electrically connected through the first current collector 5 and the separator 4, both of which are conductive.

[0251] In this embodiment, the clearance space 41 can be a through hole penetrating both ends of the partition 4 along the first direction Z, or it can be a clearance groove provided on the side of the partition 4 facing the first wall portion 13.

[0252] In an embodiment where the clearance space 41 extends through both ends of the separator 4 along the first direction Z and the separator 4 directly abuts against the first current collector 5, the projection of the first current collector 5 along the first direction Z covers the clearance space 41, such that the first current collector 5 covers one end of the clearance space 41.

[0253] In embodiments where the separator 4 includes a ring 43 and a protrusion 44, the first wall portion 13 may directly abut against the ring 43, and the protrusion 44 may directly abut against the first flow collecting member 5, such that the second flow guiding channel 42 faces the first flow collecting member 5; alternatively, the first wall portion 13 may directly abut against the protrusion 44, and the ring 43 may directly abut against the first flow collecting member 5, such that the second flow guiding channel 42 faces the first wall portion 13.

[0254] In this embodiment, by setting a first current collector 5 between the separator 4 and the electrode assembly 2, the electrical connection between the electrode assembly 2 and the separator 4 can be realized, reducing the difficulty of the electrical connection between the electrode assembly 2 and the separator 4.

[0255] In some embodiments, the separator 4 is welded to the first wall portion 13 to form a first solder area 45, and the separator 4 is welded to the first current collector 5 to form a second solder area 46. Along the first direction Z, the projection of the first solder area 45 and the projection of the second solder area 46 do not overlap.

[0256] The first solder mark area 45 is the area where the separator 4 and the first wall portion 13 are welded together to form a solder mark. The first solder mark area 45 can be the part where the separator 4 and the first wall portion 13 are welded and fused together. There can be one or more first solder mark areas 45.

[0257] The second solder area 46 is the area where the separator 4 and the first current collector 5 are welded together, forming a solder mark. The second solder area 46 can be the part where the separator 4 and the first current collector 5 are welded and fused together. There can be one or more first solder areas 45. The number of first solder areas 45 and the number of second solder areas 46 can be equal or unequal. The projections of the first solder areas 45 along the first direction Z and the projections of the second solder areas 46 along the first direction Z can be spaced apart along the circumference of the separator 4 to ensure that the projections of the first solder areas 45 and the second solder areas 46 do not overlap. Taking the number of first solder areas 45 and the number of second solder areas 46 as an example, the first solder areas 45 and the second solder areas 46 can be alternately arranged along the circumference of the separator 4.

[0258] In embodiments where the separator 4 includes a ring 43 and a protrusion 44, the ring 43 may be welded to the first wall portion 13 to form a first solder area 45, and the protrusion 44 may be welded to the first current collector 5 to form a second solder area 46; alternatively, the protrusion 44 may be welded to the first wall portion 13 to form a first solder area 45, and the ring 43 may be welded to the first current collector 5 to form a second solder area 46.

[0259] As an example, the first current collector 5 is welded to the first tab 22 of the electrode assembly 2, and the first wall portion 13, the separator 4, the first current collector 5 and the first tab 22 are made of the same material.

[0260] In this embodiment, the projection of the first solder area 45 along the first direction Z does not overlap with the projection of the second solder area 46 along the first direction Z, which can reduce the mutual interference between the first solder area 45 and the second solder area 46, and reduce the risk of poor soldering when the separator 4 is welded to the first wall portion 13 or the separator 4 is welded to the first current collector 5.

[0261] In some embodiments, the electrode assembly 2 has a first tab 22 formed at one end near the first wall portion 13 along the first direction Z. The material of the first tab 22 is different from the material of the first wall portion 13. The material of the first current collector 5 is the same as the material of the first tab 22, and the first current collector 5 is welded to the first tab 22. The material of the separator 4 is the same as the material of the first wall portion 13, and the separator 4 is welded to the first wall portion 13. The first current collector 5 and the separator 4 are connected in a composite configuration.

[0262] The material of the first electrode ear 22 can be copper, iron, aluminum, steel, aluminum alloy, etc., and the material of the first wall 13 can be copper, iron, aluminum, steel, aluminum alloy, etc. The first current collector 5 and the separator 4 can be compositely connected by hot pressing, cold pressing, friction welding, etc., so as to fix the first current collector 5 and the separator 4.

[0263] As an example, the first electrode 22 is the negative electrode, the first electrode 22 and the first current collector 5 are made of copper, and the first wall portion 13 and the separator 4 are made of aluminum.

[0264] As an example, the first electrode 22 is the negative electrode, the first electrode 22 and the first current collector 5 are made of copper, and the first wall 13 and the separator 4 are made of steel.

[0265] In this embodiment, the material of the first current collector 5 is the same as that of the first electrode 22, which reduces the welding difficulty of the first current collector 5 and the first electrode 22, improves the firmness of the welded first current collector 5 and the first electrode 22, and realizes stable current flow between the first current collector 5 and the first electrode 22; the material of the separator 4 is the same as that of the first wall portion 13, which reduces the welding difficulty of the separator 4 and the first wall portion 13, improves the firmness of the welded separator 4 and the first wall portion 13, and realizes stable current flow between the separator 4 and the first wall portion 13; the composite connection of the first current collector 5 and the separator 4 realizes stable current flow between the first current collector 5 and the separator 4, thereby realizing stable current flow between the first wall portion 13 and the first electrode 22.

[0266] In some embodiments, the electrode assembly 2 is provided with a first central hole 24, and the first current collector 5 is provided with a second central hole 51, the second central hole 51 connecting the first central hole 24 and the clearance space 41.

[0267] The clearance space 41 can be a space that passes through both ends of the separator 4 along the first direction Z, so that the second center hole 51 can connect the first center hole 24 and the clearance space 41.

[0268] As an example, electrode assembly 2 is a wound structure, with the first central hole 24 located at the winding center of the wound structure. Both the first central hole 24 and the second central hole 51 are cylindrical holes, and the first central hole 24 and the second central hole 51 are coaxially arranged, with the diameter of the first central hole 24 being larger than the diameter of the second central hole 51.

[0269] When the battery cell 10 experiences thermal runaway, the emissions generated by the electrode assembly 2 can sequentially enter the clearance space 41 through the first central hole 24 and the second central hole 51, allowing the pressure relief mechanism 131 to open and release pressure more promptly.

[0270] In some embodiments, please refer to Figures 27 and 28. Figure 27 is a structural schematic diagram of the first wall portion 13 provided in some embodiments of this application; Figure 28 is a cross-sectional view of the first wall portion 13 shown in Figure 27. The first wall portion 13 includes a wall body 132 and an abutment portion 133. The wall body 132 is provided with a pressure relief mechanism 131, and the abutment portion 133 is disposed around the outer edge of the wall body 132. Along the first direction Z, the abutment portion 133 protrudes from the wall body 132 in a direction close to the electrode assembly 2 and directly or indirectly abuts against the separator 4.

[0271] The end cap 12 can serve as the first wall portion 13, or the wall portion of the housing 11 opposite to the end cap 12 can serve as the first wall portion 13. The wall body 132 and the abutment portion 133 can be integrally formed, or they can be separately arranged and connected. The pressure relief mechanism 131 can be a pressure relief component separately arranged from the wall body 132, or it can be a structure integrally formed with the wall body 132.

[0272] The abutment portion 133 may be an annular structure surrounding the outer edge of the wall body 132. After the abutment portion 133 directly or indirectly abuts against the separator 4, the abutment portion 133 and the electrode assembly 2 may be electrically connected or insulatedly connected. As an example, the abutment portion 133 directly abuts against the separator 4 to achieve an electrical connection between the first wall portion 13 and the separator 4.

[0273] The wall body 132 and the abutment part 133 can jointly define a flow guiding space 134, which is correspondingly provided with the clearance space 41 and is connected to it. After the pressure relief mechanism 131 is opened, the emissions entering the clearance space 41 can flow through the flow guiding space 134 to the pressure relief mechanism 131, and finally be discharged to the outside of the battery cell 10 through the pressure relief mechanism 131.

[0274] In this embodiment, the abutment portion 133 protrudes from the wall body 132 in the direction close to the electrode assembly 2 and directly or indirectly abuts against the partition 4. This increases the distance between the pressure relief mechanism 131 and the partition 4, thereby further reducing the impact of the partition 4 on the pressure relief mechanism 131. It also further reduces the risk of the partition 4 directly impacting the pressure relief mechanism 131 when the electrode assembly 2 expands and deforms or the first wall portion 13 is deformed by external force, thus causing damage to the pressure relief mechanism 131.

[0275] In some embodiments, referring to FIG25, the housing 1 includes a side wall 14 separately disposed from the first wall portion 13, the side wall 14 surrounding the first wall portion 13, and the first wall portion 13 being disposed at one end of the side wall 14 along a first direction Z. At least a portion of the abutment portion 133 is received within the side wall 14 and forms a positioning engagement with the side wall 14.

[0276] The first wall portion 13 and the side wall 14 are separate parts, meaning that the first wall portion 13 and the side wall 14 are two non-integral parts. As an example, the first wall portion 13 is the end cap 12 in the outer casing 1, and the first wall portion 13 and the side wall 14 are welded together.

[0277] The portion of the abutment 133 housed within the side wall 14 forms a positioning fit with the side wall 14, such that the outer peripheral surface of the abutment 133 is in contact with the inner peripheral surface 141 of the side wall. As an example, the portion of the abutment 133 housed within the side wall 14 forms an interference fit with the side wall 14.

[0278] As an example, the first wall portion 13 may also include an edge portion 135 (shown in Figures 27 and 28), which surrounds the outer edge of the abutment portion 133 and abuts against one end of the sidewall 14 to restrict the first wall portion 13 from moving relative to the sidewall 14 toward the electrode assembly 2.

[0279] In this embodiment, the first wall portion 13 and the side wall 14 are separately provided, which facilitates the installation of the electrode assembly 2 into the housing 1. The abutment portion 133 forms a positioning fit with the side wall 14, effectively reducing the assembly difficulty of the first wall portion 13 and the side wall 14. Taking the welding of the first wall portion 13 and the side wall 14 as an example, the positioning fit between the abutment portion 133 and the side wall 14 effectively reduces the risk of radial displacement of the first wall portion 13 relative to the side wall 14 during the welding process, thus reducing the welding difficulty.

[0280] In some embodiments, please continue to refer to Figures 27 and 28, the pressure relief mechanism 131 is integrally formed with the first wall portion 13.

[0281] In this embodiment, the pressure relief mechanism 131 is integrally formed with the first wall portion 13 to form an integral pressure relief mechanism 131. The pressure relief mechanism 131 has higher reliability and eliminates the installation process of the pressure relief mechanism 131, thus having better economic efficiency.

[0282] In other embodiments, the pressure relief mechanism 131 is separately disposed from the first wall portion 13, and the pressure relief mechanism 131 is installed on the first wall portion 13.

[0283] The first wall portion 13 may be provided with a pressure relief hole, and the pressure relief mechanism 131 covers the pressure relief hole.

[0284] In this embodiment, the pressure relief mechanism 131 is separately disposed from the first wall portion 13. The pressure relief mechanism 131 is installed on the first wall portion 13, so that the pressure relief mechanism 131 is a component independent of the outer shell 1. The pressure relief mechanism 131 and the outer shell 1 can be manufactured and assembled separately, which is easy to manufacture and efficient.

[0285] In some embodiments, referring to Figures 27 and 28, the pressure relief mechanism 131 includes a weak portion 1311 and a pressure relief area 1312, with the weak portion 1311 disposed along the edge of the pressure relief area 1312.

[0286] As an example, the pressure relief mechanism 131 is provided with a pressure relief groove 136 to form a weak portion 1311 at a position corresponding to the pressure relief mechanism 131 and the pressure relief groove 136. The weak portion 1311 can be the bottom wall of the pressure relief groove 136, which is the portion of the first wall portion 13 located at the bottom of the pressure relief groove 136 along its depth direction. The pressure relief groove 136 can be located on the side of the first wall portion 13 facing the electrode assembly 2, such that the opening of the pressure relief groove 136 faces the electrode assembly 2; alternatively, the pressure relief groove 136 can be located on the side of the first wall portion 13 away from the electrode assembly 2, such that the opening of the pressure relief groove 136 faces the outside of the battery cell 10. The pressure relief groove 136 can be formed in various ways, such as stamping, laser etching, or milling. The pressure relief groove 136 can be a groove extending along a closed trajectory, which can be a circular trajectory, a rectangular trajectory, etc.; the pressure relief groove 136 can also be a groove extending along a non-closed trajectory, which can be an H-shaped trajectory, a V-shaped trajectory, a C-shaped trajectory, a Y-shaped trajectory, etc.

[0287] As an example, in the embodiment shown in Figures 27 and 28, the wall body 132 has a third surface 1321 along the first direction Z. The third surface 1321 is the outer surface of the wall body 132 and also the surface of the first wall portion 13 furthest from the electrode assembly 2 along the first direction Z. The wall body 132 is provided with a groove 137. The internal space of the groove 137 can be cylindrical, prismatic, etc. The groove 137 is recessed from the third surface 1321 toward the electrode assembly 2. A pressure relief groove 136 is provided on the bottom wall 138 of the groove. The bottom wall 138 of the groove is the portion of the first wall portion 13 located at the bottom of the groove 137 along the depth direction of the groove 137. A recess 1381 is provided on the side of the bottom wall 138 of the groove facing away from the electrode assembly 2. A reinforcing rib 1382 is formed on the side of the bottom wall 138 of the groove facing the electrode assembly 2, corresponding to the recess 1381. The reinforcing rib 1382 has the same shape as the recess 1381 and is approximately X-shaped. The pressure relief groove 136 is an annular groove that surrounds the outside of the reinforcing rib 1382. The weak portion 1311 defines a pressure relief area 1312, in which the recess 1381 and the reinforcing rib 1382 are located. When the battery cell 10 is depressurized, the wall body 132 will crack along the weak portion 1311, thereby opening the pressure relief area 1312. The reinforcing rib 1382 is used to strengthen the pressure relief area 1312, improve the deformation resistance of the pressure relief area 1312, and reduce the risk that the weak part 1311 will prematurely break due to fatigue caused by the deformation of the pressure relief area 1312 due to the internal pressure change of the battery cell 10.

[0288] In some embodiments, the housing 1 includes a housing 11 and an end cap 12, wherein the housing 11 has an opening at at least one end along a first direction Z, and the end cap 12 closes the opening. At least one end cap 12 is a first wall portion 13.

[0289] The housing 11 may have an opening at only one end along the first direction Z, with one end cap 12 correspondingly provided. Alternatively, the housing 11 may have openings at both ends along the first direction Z, with two end caps 12 correspondingly provided. The two end caps 12 respectively close the two opposite openings of the housing 11. One end cap 12 may be the first wall portion 13, or both end caps 12 may be the first wall portion 13. It is understood that the first wall portion 13 and the side wall 14 are separately provided.

[0290] In this embodiment, at least one end cap 12 is a first wall portion 13, so that at least one end cap 12 is provided with a pressure relief mechanism 131, which reduces the molding difficulty or installation difficulty of the pressure relief mechanism 131.

[0291] In some embodiments, the battery cell 10 is a cylindrical battery cell.

[0292] It is understandable that the battery cell 10 is cylindrical, and the axial direction of the battery cell 10 is parallel to the first direction Z.

[0293] This application provides a battery 100, including the battery cell 10 provided in any of the above embodiments.

[0294] This application provides an electrical device, including a battery cell 10 provided in any of the above embodiments, the battery cell 10 being used to provide electrical energy to the electrical device.

[0295] Furthermore, referring to Figures 8-11, this embodiment of the application provides a cylindrical battery cell, including a housing 1, an electrode assembly 2, a pressure relief mechanism 131, electrode terminals 3, a separator 4, a first current collector 5, and a second current collector 6. The electrode assembly 2, separator 4, first current collector 5, and second current collector 6 are all housed within the housing 1. The housing 1 includes a shell 11 and an end cap 12. The shell 11 has an opening at only one end along a first direction Z, and the end cap 12 closes the opening. The first direction Z is parallel to the axial direction of the housing 1. The electrode assembly 2 includes a main body 21, a first tab 22, and a second tab 23. The first tab 22 and the second tab 23 have opposite polarities and are respectively disposed at both ends of the main body 21 along the first direction Z. The electrode terminals 3 are insulatedly mounted on the wall portion of the housing 11 opposite to the end cap 12, and the electrode terminals 3 and the second tabs 23 are electrically connected through the second current collector 6. Along the first direction Z, the first current collector 5 and the separator 4 are disposed between the electrode assembly 2 and the end cap 12. The first current collector 5 is located between the electrode assembly 2 and the separator 4. The first current collector 5 is electrically connected to the separator 4 and the first electrode tab 22. The separator 4 is electrically connected to the first current collector 5 and the end cap 12.

[0296] Wherein, end cap 12 is the first wall portion 13 of outer shell 1, pressure relief mechanism 131 is disposed on the first wall portion 13, pressure relief mechanism 131 is configured to be able to open at least partially when battery cell 10 is depressurized, separator 4 is provided with clearance space 41, clearance space 41 is a through hole passing through both ends of separator 4 along the first direction Z, clearance space 41 is configured to avoid pressure relief mechanism 131, and the projection of separator 4 along the first direction Z does not overlap with the projection of pressure relief mechanism 131.

[0297] A first flow channel 7 is formed between the first tab 22 and the side wall 14 of the housing 11. The separator 4 includes a ring 43 and a plurality of protrusions 44. The ring 43 has opposing first surfaces 431 and second surfaces 432. A clearance space 41 extends through the first surfaces 431 and second surfaces 432. The plurality of protrusions 44 are spaced apart along the circumferential direction X of the ring 43. The protrusions 44 at least partially protrude from the first surface 431. A second flow channel 42 is formed between the portions of two adjacent protrusions 44 that protrude from the first surface 431. The second flow channel 42 connects the clearance space 41 and the first flow channel 7. Along the first direction Z, the protrusions 44 directly abut against the first flow collector 5, and the first wall portion 13 directly abuts against the ring 43.

[0298] The protrusion 44 includes a first portion 441 integrally bent from a sheet metal. The first portion 441 includes a first bent portion 4411 and a first connecting portion 4412. The first bent portion 4411 is connected to the outer peripheral surface 433 of the ring body, and the first connecting portion 4412 is connected to the first bent portion 4411. The first connecting portion 4412 is located on the side of the first surface 431 facing away from the second surface 432, and a gap is provided between the first connecting portion 4412 and the first surface 431. Along the first direction Z, the first connecting portion 4412 directly abuts against the first current collecting member 5. The first connecting portion 4412 can be a single-layer structure or a multi-layer structure formed by at least one bending.

[0299] Referring to Figures 17 and 18, this embodiment of the application provides a cylindrical battery cell, including a housing 1, an electrode assembly 2, a pressure relief mechanism 131, electrode terminals 3 (not shown in Figures 17 and 18), a separator 4, a first current collector 5 (not shown in Figures 17 and 18), and a second current collector 6. The electrode assembly 2, separator 4, first current collector 5, and second current collector 6 are all housed within the housing 1. The housing 1 includes a shell 11 and an end cap 12. The shell 11 has an opening at only one end along a first direction Z, and the end cap 12 closes the opening. The first direction Z is parallel to the axial direction of the shell 1. The electrode assembly 2 includes a main body 21, a first tab 22, and a second tab 23. The first tab 22 and the second tab 23 have opposite polarities and are respectively disposed at both ends of the main body 21 along the first direction Z. The electrode terminals 3 are insulatedly mounted on the wall portion of the shell 11 opposite to the end cap 12, and the electrode terminals 3 and the second tabs 23 are electrically connected through the second current collector 6. Along the first direction Z, the first current collector 5 and the separator 4 are disposed between the electrode assembly 2 and the end cap 12. The first current collector 5 is located between the electrode assembly 2 and the separator 4. The first current collector 5 is electrically connected to the separator 4 and the first electrode tab 22. The separator 4 is electrically connected to the first current collector 5 and the end cap 12.

[0300] Wherein, end cap 12 is the first wall portion 13 of outer shell 1, pressure relief mechanism 131 is disposed on the first wall portion 13, pressure relief mechanism 131 is configured to be able to open at least partially when battery cell 10 is depressurized, separator 4 is provided with clearance space 41, clearance space 41 is a through hole passing through both ends of separator 4 along the first direction Z, clearance space 41 is configured to avoid pressure relief mechanism 131, and the projection of separator 4 along the first direction Z does not overlap with the projection of pressure relief mechanism 131.

[0301] A first flow channel 7 is formed between the first tab 22 and the side wall 14 of the housing 11. The separator 4 includes a ring 43 and a plurality of protrusions 44. The ring 43 has opposing first surfaces 431 and second surfaces 432. A clearance space 41 extends through the first surfaces 431 and second surfaces 432. The plurality of protrusions 44 are spaced apart along the circumferential direction X of the ring 43. The protrusions 44 at least partially protrude from the first surface 431. A second flow channel 42 is formed between the portions of two adjacent protrusions 44 that protrude from the first surface 431. The second flow channel 42 connects the clearance space 41 and the first flow channel 7. Along the first direction Z, the protrusions 44 directly abut against the first flow collector 5, and the first wall portion 13 directly abuts against the ring 43.

[0302] The protrusion 44 includes a first portion 441 integrally bent from a sheet metal and a second portion 442 integrally bent from a sheet metal. The first portion 441 includes a first bent portion 4411 and a first connecting portion 4412. The first bent portion 4411 is connected to the outer peripheral surface 433 of the ring body, and the first connecting portion 4412 is connected to the first bent portion 4411. The first connecting portion 4412 is located on the side of the first surface 431 opposite to the second surface 432. The first connecting portion 4412 can be a single-layer structure or a multi-layer structure formed by at least one bend. The second portion 442 includes a third bent portion 4421 and a second connecting portion 4422. The third bent portion 4421 is connected to the inner peripheral surface 434 of the ring body, and the second connecting portion 4422 is connected to the third bent portion 4421. The second connecting portion 4422 is located on the side of the first surface 431 opposite to the second surface 432. The second connecting portion 4422 can be a single-layer structure or a multi-layer structure formed by at least one bend. Along the first direction Z, the second connection part 4422 is closer to the electrode assembly 2 than the first connection part 4412, and the second connection part 4422 directly abuts against the first current collector 5.

[0303] Referring to Figures 19 and 20, this embodiment of the application provides a cylindrical battery cell, including a housing 1, an electrode assembly 2, a pressure relief mechanism 131, electrode terminals 3 (not shown in Figures 19 and 20), a separator 4, a first current collector 5 (not shown in Figures 19 and 20), and a second current collector 6. The electrode assembly 2, separator 4, first current collector 5, and second current collector 6 are all housed within the housing 1. The housing 1 includes a shell 11 and an end cap 12. The shell 11 has an opening at only one end along a first direction Z, and the end cap 12 closes the opening. The first direction Z is parallel to the axial direction of the shell 1. The electrode assembly 2 includes a main body 21, a first tab 22, and a second tab 23. The first tab 22 and the second tab 23 have opposite polarities and are respectively disposed at both ends of the main body 21 along the first direction Z. The electrode terminals 3 are insulatedly mounted on the wall portion of the shell 11 opposite to the end cap 12, and the electrode terminals 3 and the second tabs 23 are electrically connected through the second current collector 6. Along the first direction Z, the first current collector 5 and the separator 4 are disposed between the electrode assembly 2 and the end cap 12. The first current collector 5 is located between the electrode assembly 2 and the separator 4. The first current collector 5 is electrically connected to the separator 4 and the first electrode tab 22. The separator 4 is electrically connected to the first current collector 5 and the end cap 12.

[0304] Wherein, end cap 12 is the first wall portion 13 of outer shell 1, pressure relief mechanism 131 is disposed on the first wall portion 13, pressure relief mechanism 131 is configured to be able to open at least partially when battery cell 10 is depressurized, separator 4 is provided with clearance space 41, clearance space 41 is a through hole passing through both ends of separator 4 along the first direction Z, clearance space 41 is configured to avoid pressure relief mechanism 131, and the projection of separator 4 along the first direction Z does not overlap with the projection of pressure relief mechanism 131.

[0305] A first flow channel 7 is formed between the first tab 22 and the side wall 14 of the housing 11. The separator 4 includes a ring 43 and a plurality of protrusions 44. The ring 43 has opposing first surfaces 431 and second surfaces 432. A clearance space 41 extends through the first surfaces 431 and second surfaces 432. The plurality of protrusions 44 are spaced apart along the circumferential direction X of the ring 43. The protrusions 44 at least partially protrude from the first surface 431. A second flow channel 42 is formed between the portions of two adjacent protrusions 44 that protrude from the first surface 431. The second flow channel 42 connects the clearance space 41 and the first flow channel 7. Along the first direction Z, the protrusions 44 directly abut against the first flow collector 5, and the first wall portion 13 directly abuts against the ring 43.

[0306] The protrusion 44 includes a first portion 441 integrally bent from a sheet metal and a second portion 442 integrally bent from a sheet metal. The first portion 441 includes a first bent portion 4411 and a first connecting portion 4412. The first bent portion 4411 is connected to the outer peripheral surface 433 of the ring body, and the first connecting portion 4412 is connected to the first bent portion 4411. The first connecting portion 4412 is located on the side of the first surface 431 opposite to the second surface 432. The first connecting portion 4412 can be a single-layer structure or a multi-layer structure formed by at least one bend. The second portion 442 includes a third bent portion 4421 and a second connecting portion 4422. The third bent portion 4421 is connected to the inner peripheral surface 434 of the ring body, and the second connecting portion 4422 is connected to the third bent portion 4421. The second connecting portion 4422 is located on the side of the first surface 431 opposite to the second surface 432. The second connecting portion 4422 can be a single-layer structure or a multi-layer structure formed by at least one bend. Along the first direction Z, the first connecting part 4412 is closer to the electrode assembly 2 than the second connecting part 4422, and the first connecting part 4412 directly abuts against the first current collector 5.

[0307] Referring to Figures 21 and 22, this embodiment of the application provides a cylindrical battery cell, including a housing 1, an electrode assembly 2, a pressure relief mechanism 131, electrode terminals 3 (not shown in Figures 21 and 22), a separator 4, a first current collector 5 (not shown in Figures 21 and 22), and a second current collector 6. The electrode assembly 2, separator 4, first current collector 5, and second current collector 6 are all housed within the housing 1. The housing 1 includes a shell 11 and an end cap 12. The shell 11 has an opening at only one end along a first direction Z, and the end cap 12 closes the opening. The first direction Z is parallel to the axial direction of the housing 1. The electrode assembly 2 includes a main body 21, a first tab 22, and a second tab 23. The first tab 22 and the second tab 23 have opposite polarities and are respectively disposed at both ends of the main body 21 along the first direction Z. The electrode terminals 3 are insulatedly mounted on the wall portion of the shell 11 opposite to the end cap 12, and the electrode terminals 3 and the second tabs 23 are electrically connected through the second current collector 6. Along the first direction Z, the first current collector 5 and the separator 4 are disposed between the electrode assembly 2 and the end cap 12. The first current collector 5 is located between the electrode assembly 2 and the separator 4. The first current collector 5 is electrically connected to the separator 4 and the first electrode tab 22. The separator 4 is electrically connected to the first current collector 5 and the end cap 12.

[0308] Wherein, end cap 12 is the first wall portion 13 of outer shell 1, pressure relief mechanism 131 is disposed on the first wall portion 13, pressure relief mechanism 131 is configured to be able to open at least partially when battery cell 10 is depressurized, separator 4 is provided with clearance space 41, clearance space 41 is a through hole passing through both ends of separator 4 along the first direction Z, clearance space 41 is configured to avoid pressure relief mechanism 131, and the projection of separator 4 along the first direction Z does not overlap with the projection of pressure relief mechanism 131.

[0309] A first flow channel 7 is formed between the first tab 22 and the side wall 14 of the housing 11. The separator 4 includes a ring 43 and a plurality of protrusions 44. The ring 43 has opposing first surfaces 431 and second surfaces 432. A clearance space 41 extends through the first surfaces 431 and second surfaces 432. The plurality of protrusions 44 are spaced apart along the circumferential direction X of the ring 43. At least part of the protrusions 44 protrude from the first surface 431. A second flow channel 42 is formed between the portions of two adjacent protrusions 44 that protrude from the first surface 431. The second flow channel 42 connects the clearance space 41 and the first flow channel 7. Along the first direction Z, the protrusions 44 directly abut against the first flow collector 5, and the first wall portion 13 directly abuts against the ring 43.

[0310] The protrusion 44 includes a second part 442 integrally bent from a sheet metal. The second part 442 includes a third bent portion 4421 and a second connecting portion 4422. The third bent portion 4421 is connected to the inner circumferential surface 434 of the ring body, and the second connecting portion 4422 is connected to the third bent portion 4421. The second connecting portion 4422 is located on the side of the first surface 431 facing away from the second surface 432, and a gap is provided between the second connecting portion 4422 and the first surface 431. Along the first direction Z, the second connecting portion 4422 directly abuts against the first current-collecting member 5. The second connecting portion 4422 can be a single-layer structure or a multi-layer structure formed by at least one bending.

[0311] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0312] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit this application. For those skilled in the art, this application can have various modifications and variations. 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

A battery cell, characterized in that, include: The outer casing has a first wall portion; A pressure relief mechanism is disposed on the first wall portion, the pressure relief mechanism being configured to open at least partially when the battery cell is depressurized; An electrode assembly is housed within the housing, and the electrode assembly is disposed opposite to the first wall portion along a first direction; a partition is disposed between the first wall portion and the electrode assembly, and the partition is provided with a clearance space, and along the first direction, at least part of the projection of the pressure relief mechanism is located within the clearance space, and the clearance space is configured to avoid the pressure relief mechanism. The battery cell as described in claim 1, characterized in that, The clearance space is a through hole that runs through both ends of the separator along the first direction. The battery cell as described in claim 2, characterized in that, Along the first direction, the projection of the separator does not overlap with the projection of the pressure relief mechanism. The battery cell as described in any one of claims 1-3 is characterized in that, The pressure relief mechanism includes a weak portion configured to at least partially crack when the battery cell is depressurized, and the projection of the weak portion is entirely within the clearance space along the first direction. The battery cell as described in any one of claims 1-4 is characterized in that, The outer casing includes a sidewall surrounding the first wall portion, the first wall portion being disposed at one end of the sidewall along the first direction; the electrode assembly has a first electrode tab formed at one end of the first electrode portion along the first direction near the first wall portion, a first flow channel is formed between the first electrode tab and the sidewall, the separator directly or indirectly abuts against the first electrode tab along the first direction, the separator is provided with a second flow channel, the second flow channel connecting the first flow channel and the clearance space. The battery cell as described in any one of claims 1-5 is characterized in that, The electrode assembly has a first tab formed at one end near the first wall portion along the first direction. The separator includes: a ring body having opposing first and second surfaces along the first direction, with the clearance space penetrating the first and second surfaces; and a plurality of protrusions spaced circumferentially on the ring body, each protrusion at least partially protruding from the first surface, with a second flow channel formed between the portions of two adjacent protrusions protruding from the first surface, the second flow channel communicating with the clearance space; wherein, along the first direction, one of the ring body and the protrusions directly or indirectly abuts against the first tab, and the first wall portion directly or indirectly abuts against the other of the ring body and the protrusions. The battery cell as described in claim 6, characterized in that, The battery cell includes: a first current collector, disposed between the separator and the first electrode tab along the first direction; the first current collector is electrically connected to the separator and the first electrode tab; and the first wall portion is electrically connected to the separator. Along the first direction, the protrusion directly abuts against the first current collector, the first current collector directly abuts against the first electrode tab, and the first wall portion directly abuts against the ring body. The battery cell as described in claim 7, characterized in that, The ring body is welded to the first wall portion to form a first solder mark area, and at least one of the protrusions is welded to the first current collector to form a second solder mark area. Along the first direction, the projection of the first solder mark area and the projection of the second solder mark area do not overlap. The battery cell as described in any one of claims 6-8 is characterized in that, The protrusion includes a first portion, which includes a first bend and a first connecting portion. The first bend is connected to the outer peripheral surface of the ring body, and the first connecting portion is connected to the first bend. The first connecting portion is at least partially located on the side of the first surface opposite to the second surface. The battery cell as described in claim 9, characterized in that, Along the first direction, the first connecting portion is provided with a gap from the first surface. The battery cell as described in claim 9 or 10 is characterized in that, The first connecting portion includes: a plurality of first stacked portions located on the side of the first surface away from the second surface, the plurality of first stacked portions being arranged along the first direction; and a second bending portion connecting two adjacent first stacked portions. The battery cell as described in claim 11, characterized in that, Along the first direction, two adjacent first layer stacks are spaced apart. The battery cell as described in claim 11 or 12 is characterized in that, Along the first direction, the first stacked portion furthest from the first surface is connected to the first bend; or, along the first direction, the first stacked portion closest to the first surface is connected to the first bend. The battery cell as described in any one of claims 9-13 is characterized in that, The first part is formed by bending a sheet material in one piece. The battery cell as described in any one of claims 9-14 is characterized in that, The protrusion includes a second portion, which includes a third bend and a second connecting portion. The third bend is connected to the inner circumferential surface of the ring body, and the second connecting portion is connected to the third bend. The second connecting portion is at least partially located on the side of the first surface opposite to the second surface, and the second connecting portion and the first connecting portion are arranged along the first direction. The first connecting portion is closer to the first surface along the first direction than the second connecting portion; or the second connecting portion is closer to the first surface along the first direction than the first connecting portion. The battery cell as described in any one of claims 6-14 is characterized in that, The protrusion includes a second portion, which includes a third bend and a second connecting portion. The third bend is connected to the inner circumferential surface of the ring body, and the second connecting portion is connected to the third bend. The second connecting portion is at least partially located on the side of the first surface opposite to the second surface. The battery cell as described in claim 16, characterized in that, Along the first direction, the second connecting portion is spaced apart from the first surface. The battery cell as described in claim 16 or 17 is characterized in that, The second connecting portion includes: a plurality of second stacked portions located on the side of the first surface away from the second surface, the plurality of second stacked portions being arranged along the first direction; and a fourth bending portion connecting two adjacent second stacked portions. The battery cell as described in claim 18, characterized in that, Along the first direction, two adjacent second layer stacks are spaced apart. The battery cell as described in claim 18 or 19 is characterized in that, Along the first direction, the second layered portion furthest from the first surface is connected to the third bend; or, along the first direction, the second layered portion closest to the first surface is connected to the third bend. The battery cell as described in any one of claims 15-20 is characterized in that, The second part is formed by bending a sheet material in one piece. The battery cell as described in any one of claims 6-21 is characterized in that, Along the first direction, the minimum thickness of the ring is D, where D ≥ 0.3 mm. The battery cell as described in any one of claims 6-22 is characterized in that, The separator is electrically connected to the first wall portion and the first electrode ear. Along the circumference of the ring body, the sum of the maximum dimensions of all the protrusions is A1, and the sum of the maximum dimensions of all the second flow channels is A2, 0.1≤A1 / (A1+A2)≤0.

8. The battery cell as described in any one of claims 1-23 is characterized in that, The separator is electrically connected to the first wall portion and the electrode assembly. The battery cell as described in claim 24, characterized in that, The battery cell includes: a first current collector, disposed between the separator and the electrode assembly along the first direction, the first current collector being electrically connected to the separator and the electrode assembly, and the projection of the first current collector covering the clearance space along the first direction. The battery cell as described in claim 25, characterized in that, The separator is welded to the first wall portion to form a first solder mark area, and the separator is welded to the first current collector to form a second solder mark area. Along the first direction, the projection of the first solder mark area and the projection of the second solder mark area do not overlap. The battery cell as described in claim 25, characterized in that, The electrode assembly has a first tab formed at one end near the first wall portion along the first direction, and the material of the first tab is different from the material of the first wall portion; wherein, the material of the first current collector is the same as the material of the first tab, and the first current collector is welded to the first tab; the material of the separator is the same as the material of the first wall portion, and the separator is welded to the first wall portion; the first current collector and the separator are combined and connected. The battery cell as described in any one of claims 25-27 is characterized in that, The electrode assembly is provided with a first central hole, and the first current collector is provided with a second central hole, the second central hole connecting the first central hole and the clearance space. The battery cell as described in any one of claims 1-28 is characterized in that, The first wall portion includes a wall body and an abutment portion. The wall body is provided with the pressure relief mechanism, and the abutment portion is disposed around the outer edge of the wall body. Along the first direction, the abutment portion protrudes from the wall body in a direction close to the electrode assembly and directly or indirectly abuts against the separator. The battery cell as described in claim 29, characterized in that, The outer casing includes a sidewall that is integrally disposed with the first wall portion, the sidewall surrounding the first wall portion, and the first wall portion being disposed at one end of the sidewall along the first direction; at least a portion of the abutment portion is accommodated within the sidewall and forms a positioning engagement with the sidewall. The battery cell as described in any one of claims 1-30 is characterized in that, The pressure relief mechanism is integrally formed with the first wall portion; or, the pressure relief mechanism is separately disposed from the first wall portion, and the pressure relief mechanism is installed on the first wall portion. The battery cell as described in any one of claims 1-31 is characterized in that, The outer casing includes: a housing having an opening at at least one end along the first direction; and an end cap closing the opening; wherein at least one of the end caps is the first wall portion. The battery cell as described in any one of claims 1-32 is characterized in that, The battery cell is a cylindrical battery cell. A battery characterized in that, Includes the battery cell as described in any one of claims 1-33. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-33, the battery cell being used to provide electrical energy to the electrical equipment.

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