Battery cell, battery device, and electric device

Abstract

The application provides a battery cell, a battery device and a power utilization device. The battery cell comprises an electrode assembly, a shell, a pressure relief mechanism and a support. The shell contains the electrode assembly. The shell has a wall part, which is arranged opposite the electrode assembly along a first direction. The wall part has a first surface facing the electrode assembly along the first direction. The wall part is provided with a pressure relief hole, one end of which extends to the first surface. The pressure relief mechanism abuts against the first surface and covers the pressure relief hole. The pressure relief mechanism is welded to the wall part to form a welding mark part. The support is at least partially arranged between the electrode assembly and the wall part along the first direction, and supports the electrode assembly. The support is provided with a relief part, which contains at least part of the welding mark part. When the pressure relief mechanism is subjected to internal pressure of the battery cell, the first surface can share the stress of the welding mark part, thereby reducing the risk of damage to the welding mark part. The relief part can avoid the welding mark part, thereby reducing the risk of interference between the welding mark part and the support and prolonging the service life of the battery cell.

Description

Technical Field

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

[0002] Batteries are widely used in the new energy field, such as in electric vehicles and new energy vehicles, which have become a new trend in the automotive industry. The development of battery technology must consider multiple design factors simultaneously, such as energy density, discharge capacity, and charge / discharge rate. Additionally, battery cycle life must be considered. However, currently, the cycle life of batteries is relatively short. Utility Model Content

[0003] The purpose of this application is to provide a battery cell, a battery device, and an electrical device, which aims to improve the problem of short battery life in related technologies.

[0004] In a first aspect, embodiments of this application provide a battery cell, the battery cell including an electrode assembly, a housing, a pressure relief mechanism, and a support member. The housing accommodates the electrode assembly and has a wall portion. The wall portion and the electrode assembly are disposed opposite each other along a first direction. The wall portion has a first surface facing the electrode assembly along the first direction. The wall portion is provided with a pressure relief hole, one end of which extends to the first surface. The pressure relief mechanism abuts against the first surface and covers the pressure relief hole. The pressure relief mechanism is welded to the wall portion to form a solder mark. The support member is at least partially disposed between the electrode assembly and the wall portion along the first direction. The support member supports the electrode assembly and is provided with a clearance portion that accommodates at least a portion of the solder mark.

[0005] In the above technical solution, the wall portion has a first surface facing the electrode assembly along a first direction. The pressure relief mechanism abuts against the first surface and covers the pressure relief hole, that is, the pressure relief mechanism is located on the side of the pressure relief hole facing the electrode assembly. The pressure relief mechanism is welded to the wall portion to form a solder joint. When the pressure relief mechanism is subjected to pressure from inside the battery cell, the first surface can distribute the force because the pressure relief mechanism abuts against it, reducing the stress on the solder joint, thereby reducing the risk of damage to the solder joint and extending the life of the battery cell. By providing a support member to support the electrode assembly, the risk of interference between the electrode assembly and other components is reduced, the stress on the electrode assembly is reduced, thereby reducing the risk of damage to the electrode assembly and extending the life of the battery cell. By providing a clearance portion on the support member, the clearance portion can avoid the solder joint, thereby reducing the risk of interference between the solder joint and the support member. On the one hand, this reduces the external force on the solder joint and the risk of damage to the solder joint. On the other hand, it allows the support member to support the electrode assembly more stably, thereby reducing the risk of damage to the electrode assembly and extending the life of the battery cell.

[0006] As an optional technical solution in this application embodiment, the avoidance part is an exhaust channel provided on the support member.

[0007] In the above technical solution, the clearance part can not only avoid the soldering part, but also serve as an exhaust channel. When the battery cell is depressurized, the fluid medium inside the casing can flow to the depressurization mechanism through the exhaust channel to release the pressure, reducing the risk of pressure buildup and improving the reliability of the battery cell.

[0008] As an optional technical solution in this application embodiment, the support member includes a connected support plate and a support portion. Along the first direction, the support plate is disposed opposite to the wall portion, and the support portion is disposed between the support plate and the wall portion. The space between the support plate and the wall portion that is not occupied by the support portion forms the clearance portion.

[0009] In the above technical solution, by setting a support part on the side of the support plate facing the wall, the support part can support the support plate, so that there is a gap between the support plate and the wall. The space between the support plate and the wall that is not occupied by the support part forms a clearance part. It is simple, convenient, easy to manufacture, and has a low cost.

[0010] As an optional technical solution in this application embodiment, the support member includes a plurality of support portions, which are spaced apart on the support plate.

[0011] In the above technical solution, by setting multiple support parts, on the one hand, the support plate can be better supported, enabling the support plate to better support the electrode assembly and reducing the risk of damage to the electrode assembly. On the other hand, the space between the multiple support parts is relatively large, leaving a large unoccupied space, which makes the clearance part larger, better avoiding the soldering part, and better guiding the fluid medium inside the casing to the pressure relief mechanism for pressure relief, which is beneficial to improving the life and reliability of the battery cell.

[0012] As an optional technical solution in this application embodiment, there is a gap between the solder mark and the support plate along the first direction.

[0013] In the above technical solution, by creating a gap between the solder joint and the support plate, interference between them is less likely. On the one hand, this reduces the external force on the solder joint, lowering the risk of damage. On the other hand, it allows the support plate to more stably support the electrode assembly, thereby reducing the risk of damage to the electrode assembly and extending the lifespan of the battery cell.

[0014] As an optional technical solution in this application embodiment, the avoidance part is a through hole provided in the support member, and the through hole penetrates two surfaces of the support member that are disposed opposite to each other along the first direction.

[0015] In the above technical solution, the avoidance part is a through hole set in the support member, which can effectively avoid the soldering part, reduce the risk of interference between the soldering part and the support member, and facilitate the flow of the fluid medium in the battery cell to the pressure relief mechanism, which is beneficial to open the pressure relief mechanism to relieve pressure when the pressure inside the battery cell reaches the threshold.

[0016] As an optional technical solution in this application embodiment, the support member includes a first part and a second part that are separately arranged. Along the first direction, at least a portion of the first part and at least a portion of the second part are located between the electrode assembly and the wall portion. Along the second direction, the first part and the second part are spaced apart, and the space between the first part and the second part forms the clearance portion. The second direction is perpendicular to the first direction.

[0017] In the above technical solution, the support component includes a first part and a second part that are separately arranged, so that the space between the first part and the second part forms a clearance portion. On the one hand, this effectively avoids the risk of interference between the soldering portion and the support component. On the other hand, it facilitates the flow of the fluid medium inside the battery cell to the pressure relief mechanism, making it less likely to affect the opening of the pressure relief mechanism, which is beneficial for the pressure relief mechanism to open when the pressure inside the battery cell reaches the threshold. Furthermore, during manufacturing, the first part and the second part can be manufactured separately and then set on both sides of the soldering portion, which simplifies manufacturing and reduces assembly difficulty.

[0018] As an optional technical solution in this application embodiment, the solder stamp portion does not contact the support member; and / or the solder stamp portion does not contact the electrode assembly.

[0019] In the above technical solution, by preventing the solder joint from contacting the support component, the risk of interference between the solder joint and the support component can be reduced. On the one hand, this reduces the external force on the solder joint, lowering the risk of damage. On the other hand, it allows the support component to more stably support the electrode assembly, thereby reducing the risk of damage to the electrode assembly and extending the lifespan of the battery cell.

[0020] As an optional technical solution in this application embodiment, the wall portion has a second surface facing the electrode assembly, the second surface is provided with a mounting groove, the bottom surface of the mounting groove is the first surface, and the pressure relief mechanism is at least partially accommodated in the mounting groove.

[0021] In the above technical solution, by providing a mounting groove on the second surface and accommodating at least a portion of the pressure relief mechanism within the mounting groove, the height of the pressure relief mechanism extending beyond the second surface along the wall towards the electrode assembly is reduced. This reduces the risk of interference between the pressure relief mechanism and other components, minimizes the impact on burst pressure, and improves the reliability of the battery cell. Furthermore, it reduces the space occupied by the pressure relief mechanism within the battery cell, thereby increasing the energy density of the battery cell.

[0022] As an optional technical solution in this application embodiment, the second surface is the surface of the wall closest to the electrode assembly, the solder mark protrudes from the second surface, and the clearance portion accommodates the portion of the solder mark protruding from the second surface.

[0023] In the above technical solution, the solder stamp protrudes from the surface of the wall closest to the electrode assembly, and the clearance portion accommodates the portion of the solder stamp protruding from the surface of the wall closest to the electrode assembly, so as to further reduce the risk of interference between the solder stamp and the support.

[0024] As an optional technical solution in this application embodiment, along the first direction, the wall portion has a third surface facing the electrode assembly, the wall portion includes a protrusion, the protrusion at least partially protruding from the third surface in the direction of the wall portion pointing towards the electrode assembly, the end face of the protrusion facing the electrode assembly is the second surface, the support member abuts against the third surface, and the clearance portion accommodates at least a portion of the protrusion.

[0025] In the above technical solution, at least a portion of the protrusion extends from the third surface along the direction from the wall portion toward the electrode assembly. A mounting groove is provided on the protrusion to accommodate at least a portion of the pressure relief mechanism. This allows the pressure relief mechanism to be positioned further away from the outer surface of the wall portion, thereby reducing the risk of external impacts on the pressure relief mechanism and improving the reliability of the battery cell. The clearance portion can avoid at least a portion of the protrusion, reducing the risk of interference between the protrusion and the support member. This allows the support member to more stably support the electrode assembly, thereby reducing the risk of damage to the electrode assembly and extending the lifespan of the battery cell.

[0026] As an optional technical solution in this application embodiment, the wall portion includes a main body area and an overlapping area that overlaps with the pressure relief mechanism along a first direction. The surface of the overlapping area facing the electrode assembly is the first surface. The pressure relief hole is located in the overlapping area. The main body area is arranged around the overlapping area. Along the first direction, the minimum thickness of the main body area is H1, and the minimum thickness of the overlapping area is H2, satisfying: 0.5≤H2 / H1≤1, and optionally, 0.6≤H2 / H1≤0.9.

[0027] In the above technical solution, when H2 / H1≥0.5, the minimum thickness of the overlapping area is relatively large, resulting in higher strength. This effectively supports the pressure relief mechanism, distributes the stress on the solder joint, reduces the risk of solder joint damage, and helps extend the lifespan of the battery cell. When H2 / H1≤1, the minimum thickness of the overlapping area is not too large. On the one hand, this helps reduce the risk of interference between the overlapping area and other components; on the other hand, it facilitates manufacturing and helps reduce manufacturing costs. Therefore, when 0.5≤H2 / H1≤1, both the lifespan of the battery cell and manufacturing costs can be balanced.

[0028] When H2 / H1 ≥ 0.6, the minimum thickness of the overlapping area is greater, resulting in higher strength. This effectively supports the pressure relief mechanism, distributes the stress on the solder joint, reduces the risk of solder joint damage, and helps extend the lifespan of the battery cell. When H2 / H1 ≤ 0.9, the minimum thickness of the overlapping area is not too large. On the one hand, this helps reduce the risk of interference between the overlapping area and other components; on the other hand, it facilitates manufacturing and helps reduce manufacturing costs. Therefore, when 0.6 ≤ H2 / H1 ≤ 0.9, it better balances the lifespan of the battery cell and manufacturing costs.

[0029] As an optional technical solution in this application embodiment, the housing includes a shell and an end cap. The shell has an opening, and the end cap closes the opening. The shell includes a wall portion, and the wall portion is disposed opposite to the end cap along the first direction.

[0030] In the above technical solution, the wall portion is the bottom wall of the casing, which is opposite to the end cap, and the pressure relief mechanism is located on the bottom wall. In this way, when a battery cell is depressurized, the fluid medium inside the battery cell can be ejected from the bottom of the battery cell, which helps reduce the risk of personal injury caused by the fluid medium and improves the reliability of the battery cell.

[0031] Secondly, embodiments of this application also provide a battery device, which includes the aforementioned battery cell.

[0032] Thirdly, embodiments of this application also provide an electrical device, which includes the aforementioned battery cell, and the battery cell is used to provide electrical energy to the electrical device. Attached Figure Description

[0033] 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.

[0034] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0035] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0036] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0037] Figure 4 Exploded views of a single battery cell provided in some embodiments of this application;

[0038] Figure 5 Exploded views of the housing, pressure relief mechanism, and support provided for some embodiments of this application;

[0039] Figure 6 A partial cross-sectional view of a battery cell (equipped with a pressure relief mechanism) provided in some embodiments of this application;

[0040] Figure 7 for Figure 6 A magnified view of position A in the middle;

[0041] Figure 8 Partial cross-sectional view of a battery cell (without pressure relief mechanism installed) provided in some embodiments of this application;

[0042] Figure 9 for Figure 8 A magnified view of position B in the middle;

[0043] Figure 10 This is a schematic diagram of the structure of the support member provided in some other embodiments of this application;

[0044] Figure 11 This is a structural schematic diagram of a support member provided in some embodiments of this application.

[0045] Icons: 10-Box body; 11-First box body; 12-Second box body; 20-Battery cell; 21-Outer shell; 211-Shell; 2111-Side wall; 2112-Bottom wall; 212-End cap; 213-Wall section; 2131-Pressure relief hole; 2132-First surface; 2133-Protrusion; 21331-Second surface; 2134-Third surface; 2135-Overlapping area; 21351-Fifth surface; 2136-Main body area; 2137-Fourth surface; 2138- 2139 - Recess; 22 - Mounting groove; 22 - Electrode assembly; 221 - Main body; 222 - Electrode tab; 23 - Pressure relief mechanism; 231 - Soldering part; 232 - Weak part; 233 - Pressure relief area; 24 - Support member; 241 - Support plate; 242 - Support part; 243 - Clearance part; 244 - First part; 245 - Second part; 25 - Electrode terminal; 26 - Protective component; 27 - Insulating component; 100 - Battery device; 200 - Controller; 300 - Motor; 1000 - Vehicle. Detailed Implementation

[0046] 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.

[0047] 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.

[0048] 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.

[0049] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0050] 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.

[0051] 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.

[0052] In this application, "multiple" means two or more (including two).

[0053] 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.

[0054] 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.

[0055] 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.

[0056] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0057] 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.

[0058] As an example, the positive electrode current collector can be a foil or a composite current collector. For example, as a foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0059] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials in battery cells 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 / 3Mn 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 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 )), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0060] 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.

[0061] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0062] As an example, the negative electrode current collector can be a foil, a foamed metal, or a composite current collector. For example, as a foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, carbon electrodes, carbon, nickel, or titanium, etc. The foamed metal can be nickel foam, copper foam, aluminum foam, foam alloy, etc. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0063] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0064] 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.

[0065] 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 negative electrode active materials in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0066] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0073] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0074] In some implementations, the electrode assembly is a stacked structure.

[0075] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0076] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0077] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0078] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0079] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0080] In some implementations, the electrode assembly may be flat or polygonal in shape.

[0081] 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.

[0082] 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, or a composite metal (such as a copper-aluminum composite housing).

[0083] In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a sealed structure, it can protect the electrode assembly and prevent, to some extent, electrolyte leakage. When the housing is a non-sealed structure, it can still protect the electrode assembly, and a sealing bag may be included between the housing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag can be a bag-shaped insulating material or an aluminum-plastic film.

[0084] As an example, a battery cell can be a prismatic 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.

[0085] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0086] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging multiple battery cells and fixing them together to form an independent module.

[0087] As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0088] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more battery cell assemblies housed within the housing.

[0089] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0090] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0091] As an example, the enclosure may include a first enclosure body and a second enclosure body. The first enclosure body and the second enclosure body are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, which can be either sealed or unsealed. The first enclosure body may be a top cover or a bottom plate.

[0092] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0093] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0094] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0095] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0096] The development of battery technology must consider multiple design factors simultaneously, such as energy density, discharge capacity, and charge / discharge rate. Additionally, cycle life must be considered. However, current battery cycle life is relatively short.

[0097] To improve the reliability of individual battery cells, existing technologies involve creating pressure relief holes in the walls of the cell's casing, welding a pressure relief mechanism to the wall, and covering the pressure relief holes. When the internal pressure of the battery cell reaches the burst pressure, the pressure relief mechanism opens to release the internal pressure, thereby reducing the risk of the battery cell exploding or catching fire.

[0098] However, in related technologies, the pressure relief mechanism is welded to the side of the pressure relief hole away from the inside of the casing. During the use of the battery cell, the pressure relief mechanism is easily subjected to the internal pressure of the battery cell, resulting in outward pressure on the mechanism. This outward pressure is ultimately borne by the weld mark formed by the welding connection between the pressure relief mechanism and the wall. If the strength of the weld mark is insufficient, it will lead to the damage of the weld mark, causing premature failure of the battery cell and a shorter lifespan.

[0099] In view of this, this application provides a battery cell, which includes an electrode assembly, a housing, a pressure relief mechanism, and a support member. The housing houses the electrode assembly. The housing has a wall portion, which is disposed opposite to the electrode assembly along a first direction. The wall portion has a first surface facing the electrode assembly along the first direction, and the wall portion is provided with a pressure relief hole, one end of which extends to the first surface. The pressure relief mechanism abuts against the first surface and covers the pressure relief hole, and the pressure relief mechanism is welded to the wall portion to form a solder mark portion. The support member is at least partially disposed between the electrode assembly and the wall portion along the first direction, and the support member supports the electrode assembly. The support member is provided with a clearance portion, which accommodates at least a portion of the solder mark portion.

[0100] The wall portion has a first surface facing the electrode assembly along a first direction. A pressure relief mechanism abuts against the first surface and covers the pressure relief hole; that is, the pressure relief mechanism is located on the side of the pressure relief hole facing the electrode assembly. The pressure relief mechanism is welded to the wall portion to form a solder joint. When the pressure relief mechanism is subjected to pressure from inside the battery cell, the first surface distributes the force, reducing the stress on the solder joint, thus reducing the risk of damage to the solder joint and extending the battery cell's lifespan. By providing a support member to support the electrode assembly, the risk of interference between the electrode assembly and other components is reduced, as is the stress on the electrode assembly, further reducing the risk of damage and extending the battery cell's lifespan. By providing a clearance portion on the support member, the clearance portion can avoid the solder joint, reducing the risk of interference between the solder joint and the support member. On the one hand, this reduces the external force on the solder joint, lowering the risk of damage. On the other hand, it allows the support member to support the electrode assembly more stably, further reducing the risk of damage and extending the battery cell's lifespan.

[0101] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0102] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0103] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. A battery device 100 is disposed inside the vehicle 1000, and the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000.

[0104] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0105] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0106] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 may include a housing 10 and battery cells 20, the housing 10 being used to house the battery cells 20.

[0107] The housing 10 has an enclosed space inside for accommodating the battery cells 20. The housing 10 can have various structures. In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, which are interlocked. The first housing body 11 and the second housing body 12 can have various shapes, such as cuboids or cylinders. The first housing body 11 can be a hollow structure open on one side, and the second housing body 12 can also be a hollow structure open on one side. The open side of the second housing body 12 interlocks with the open side of the first housing body 11, thus forming a housing 10 with an enclosed space. Alternatively, the first housing body 11 can be a hollow structure open on one side, and the second housing body 12 can be a plate-like structure, with the second housing body 12 interlocked with the open side of the first housing body 11, thus forming a housing 10 with an accommodating chamber.

[0108] In the battery device 100, there can be one or more battery cells 20. If there are multiple battery cells 20, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel. Alternatively, multiple battery cells 20 can be first connected in series, parallel, or in a mixed configuration to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10. Another option is that all battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the whole consisting of all battery cells 20 is housed within the housing 10.

[0109] In some embodiments, the battery device 100 may further include a busbar component, through which multiple battery cells 20 can be electrically connected to each other to achieve series, parallel, or mixed connection of the multiple battery cells 20. The busbar component may be a metallic conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0110] Please refer to Figure 3, Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 , Figure 3 This is a schematic diagram of the structure of a battery cell 20 provided in some embodiments of this application. Figure 4 An exploded view of a battery cell 20 provided in some embodiments of this application. Figure 5 Exploded views of the housing 211, pressure relief mechanism 23, and support member 24 provided for some embodiments of this application. Figure 6 This is a partial cross-sectional view of a battery cell 20 (with a pressure relief mechanism 23) provided in some embodiments of this application. Figure 7 for Figure 6 A magnified view of position A in the middle. Figure 8 This is a partial cross-sectional view of a battery cell 20 (without pressure relief mechanism 23) provided in some embodiments of this application. Figure 9 for Figure 8 Enlarged view of position B. This application provides a battery cell 20, which includes an electrode assembly 22, a housing 21, a pressure relief mechanism 23, and a support member 24. The housing 21 houses the electrode assembly 22. The housing 21 has a wall portion 213, which is disposed opposite to the electrode assembly 22 along a first direction. The wall portion 213 has a first surface 2132 facing the electrode assembly 22 along the first direction, and a pressure relief hole 2131 is provided in the wall portion 213, one end of which extends to the first surface 2132. The pressure relief mechanism 23 abuts against the first surface 2132 and covers the pressure relief hole 2131, and is welded to the wall portion 213 to form a solder mark portion 231. The support member 24 is at least partially disposed between the electrode assembly 22 and the wall portion 213 along the first direction, and supports the electrode assembly 22. The support member 24 has a clearance portion 243 that accommodates at least a portion of the solder mark portion 231.

[0111] Battery cell 20 refers to the smallest unit that makes up battery device 100.

[0112] The housing 21 includes a housing 211 and an end cap 212. The housing 211 has a receiving space with an opening at one end for accommodating the electrode assembly 22. The end cap 212 is connected to the housing 211 and closes the opening.

[0113] End cap 212 refers to a component that covers the opening of housing 211 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 212 can be adapted to the shape of housing 211 to fit it. Optionally, end cap 212 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that end cap 212 is not easily deformed under pressure and impact, giving battery cell 20 higher structural strength and improved reliability. The material of end cap 212 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. Battery cell 20 also includes an insulating member 27, which is disposed inside end cap 212. The insulating member 27 can be used to isolate the electrical connection components inside housing 211 from end cap 212 to reduce the risk of short circuit. For example, insulating member 27 can be plastic, rubber, etc.

[0114] The housing 211 is a component used to cooperate with the end cap 212 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 22, electrolyte, and other components. The housing 211 and the end cap 212 can be independent components. An opening can be provided on the housing 211, and the end cap 212 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 212 and the housing 211 can be integrated. Specifically, the end cap 212 and the housing 211 can form a common mating surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 211, the end cap 212 closes the housing 211. The housing 211 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the electrode assembly 22. The material of the housing 211 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0115] In some embodiments, the housing 211 may have an opening at only one end, with one end cap 212 correspondingly provided. In other embodiments, the housing 211 may have openings at both ends, with two end caps 212 correspondingly provided, the two end caps 212 respectively closing the two opposite openings of the housing 211. Figure 3 and Figure 4 In the embodiment shown, the housing 211 has an opening at only one end, and an end cap 212 is provided accordingly.

[0116] Electrode terminals 25 may also be provided on the end cap 212 or the housing 211. These terminals are used for electrical connection to the tabs 222 of the electrode assembly 22 to input or output electrical energy from the battery cell 20. The electrode terminals 25 and tabs 222 can be directly connected, for example, by direct welding. Alternatively, they can be indirectly connected, for example, through a current collector. The current collector can be a metallic conductor, such as copper, iron, aluminum, steel, or aluminum alloy.

[0117] Electrode assembly 22 is the component in the battery cell 20 where electrochemical reactions occur. The housing 211 may contain one or more electrode assemblies 22. The electrode assembly 22 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body 221 of the electrode assembly 22, while the portions of the positive and negative electrode sheets without active material each constitute a tab 222. The positive and negative tabs may be located together at one end of the main body 221 or separately at both ends of the main body 221. During the charging and discharging process of the battery cell 20, the positive and negative active materials react with the electrolyte.

[0118] The wall portion 213 can be an end cap 212 of the outer casing 21, or it can be a wall of the housing 211 of the outer casing 21. For example, in... Figure 3 and Figure 4 In some embodiments, the wall portion 213 is the bottom wall 2112 of the housing 211, which is disposed opposite to the end cap 212. In other embodiments, the wall portion 213 is the end cap 212. In still other embodiments, the housing 211 includes a plurality of side walls 2111, and the wall portion 213 is one of the plurality of side walls 2111.

[0119] The wall portion 213 is provided with a pressure relief hole 2131, which is a through hole that penetrates two opposing surfaces of the wall portion 213 along the thickness direction of the wall portion 213.

[0120] The pressure relief mechanism 23 is a component used to open when the internal pressure or temperature of the battery cell 20 reaches the burst pressure, thereby releasing the internal pressure of the battery cell 20. During manufacturing, a pressure relief hole 2131 is provided in the wall portion 213. The pressure relief mechanism 23 and the wall portion 213 are provided separately and ultimately connected together, with the pressure relief mechanism 23 covering the pressure relief hole 2131. For example, the pressure relief mechanism 23 can be welded to the wall portion 213. The pressure relief mechanism 23 can be a burst-proof plate mounted on the wall portion 213.

[0121] The pressure relief mechanism 23 can be partially housed within the pressure relief hole 2131 and partially located outside the pressure relief hole 2131, or it can be completely housed within the pressure relief hole 2131.

[0122] The pressure relief mechanism 23 includes a weak portion 232, which serves to relieve pressure. When the internal pressure or temperature of the battery cell 20 reaches a predetermined value, the pressure relief mechanism 23 can crack along the weak portion 232 to release the internal pressure of the battery cell 20. In some embodiments, the strength of the pressure relief mechanism 23 at the weak portion 232 may be lower than the strength at other locations of the pressure relief mechanism 23. This allows the weak portion 232 to crack under the internal pressure when the internal pressure or temperature of the battery cell 20 reaches the predetermined value, thus releasing the internal pressure of the battery cell 20. In other embodiments, the melting point of the pressure relief mechanism 23 at the weak portion 232 may be lower than the melting point at other locations of the pressure relief mechanism 23. This allows the weak portion 232 to crack under high temperature when the internal pressure or temperature of the battery cell 20 reaches the predetermined value, thus releasing the internal pressure of the battery cell 20.

[0123] The location of the pressure relief mechanism 23 can be used to determine which wall of the housing 21 is wall portion 213. For example, when the pressure relief mechanism 23 is located on the end cap 212, then the end cap 212 is wall portion 213. When the pressure relief mechanism 23 is located on the bottom wall 2112 of the housing 211, then the bottom wall 2112 is wall portion 213. When the pressure relief mechanism 23 is located on one side wall 2111 of the housing 211, then that side wall 2111 is wall portion 213.

[0124] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 The first direction is the X direction shown in the figure.

[0125] Along a first direction, the wall portion 213 is disposed opposite to the electrode assembly 22. The wall portion 213 has a first surface 2132 facing the electrode assembly 22 along the first direction, and one end of the pressure relief hole 2131 extends to the first surface 2132. In other words, the pressure relief hole 2131 penetrates the first surface 2132 and another surface of the wall portion 213 disposed opposite to the first surface 2132.

[0126] Along the first direction, the pressure relief mechanism 23 abuts against the first surface 2132 and covers the pressure relief hole 2131. In other words, the pressure relief mechanism 23 is disposed on the side of the pressure relief hole 2131 facing the electrode assembly 22, and at least a portion of the wall portion 213 abuts against the side of the pressure relief mechanism 23 opposite to the electrode assembly 22.

[0127] In some embodiments, the battery cell 20 further includes a protective member 26, which is disposed on the side of the pressure relief hole 2131 away from the electrode assembly 22 and covers the pressure relief hole 2131. The protective member 26 can protect the pressure relief mechanism 23 and further reduce the risk of the pressure relief mechanism 23 being subjected to external impacts.

[0128] The weld mark 231 is a weld formed by welding the pressure relief mechanism 23 and the wall 213.

[0129] The support member 24 is a support structure disposed along a first direction between the wall portion 213 and the electrode assembly 22, and the support member 24 is used to support the electrode assembly 22. Understandably, the support member 24 is located at the bottom of the electrode assembly 22 so that the support member 24 can support the electrode assembly 22 in the direction of gravity. For example, the support member 24 can be a base plate.

[0130] The support member 24 is made of insulating material, which can insulate and isolate the electrode assembly 22 and the wall portion 213, reducing the risk of short circuit due to contact between the electrode assembly 22 and the wall portion 213. For example, the support member 24 can be made of plastic, rubber, or other materials.

[0131] The support member 24 is provided with a relief portion 243, which is used to avoid at least a portion of the solder mark portion 231. The relief portion 243 can be a groove provided in the support member 24, or it can be a through hole provided in the support member 24.

[0132] The wall portion 213 has a first surface 2132 facing the electrode assembly 22 along a first direction. The pressure relief mechanism 23 abuts against the first surface 2132 and covers the pressure relief hole 2131, that is, the pressure relief mechanism 23 is disposed on the side of the pressure relief hole 2131 facing the electrode assembly 22. The pressure relief mechanism 23 is welded to the wall portion 213 to form a solder mark 231. When the pressure relief mechanism 23 is subjected to pressure from inside the battery cell 20, since the pressure relief mechanism 23 abuts against the first surface 2132, the first surface 2132 can distribute the force, reducing the stress on the solder mark 231, thereby reducing the risk of damage to the solder mark 231 and extending the life of the battery cell 20. By providing a support member 24 to support the electrode assembly 22, the risk of interference between the electrode assembly 22 and other components is reduced, the stress on the electrode assembly 22 is reduced, thereby reducing the risk of damage to the electrode assembly 22 and extending the life of the battery cell 20. By providing a clearance portion 243 on the support member 24, the clearance portion 243 can avoid the solder stamp portion 231, thereby reducing the risk of interference between the solder stamp portion 231 and the support member 24. On the one hand, it can reduce the external force on the solder stamp portion 231 and reduce the risk of the solder stamp portion 231 being damaged. On the other hand, it can enable the support member 24 to support the electrode assembly 22 more stably, thereby reducing the risk of damage to the electrode assembly 22 and helping to extend the life of the battery cell 20.

[0133] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 In some embodiments, the clearance portion 243 is an exhaust channel provided on the support member 24.

[0134] The clearance section 243 can be used as an exhaust channel, and the clearance section 243 can guide the fluid medium inside the casing 21 to the pressure relief mechanism 23 when the battery cell 20 is depressurized.

[0135] The clearance part 243 can not only avoid the soldering part 231, but also serve as an exhaust channel. When the battery cell 20 is depressurized, the fluid medium inside the casing 21 can flow to the pressure relief mechanism 23 through the exhaust channel to relieve pressure, reducing the risk of pressure buildup and improving the reliability of the battery cell 20.

[0136] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9In some embodiments, the support member 24 includes a connected support plate 241 and a support portion 242. Along a first direction, the support plate 241 is disposed opposite to the wall portion 213, and the support portion 242 is disposed between the support plate 241 and the wall portion 213. The space between the support plate 241 and the wall portion 213 that is not occupied by the support portion 242 forms a clearance portion 243.

[0137] The support plate 241 is the main part of the support member 24 that supports the electrode assembly 22. The support plate 241 has a plate structure. The side of the support plate 241 that is away from the support part 242 is relatively flat. The side of the support plate 241 that is away from the support part 242 can directly contact the electrode assembly 22 and support the electrode assembly 22, so as to reduce the stress on the electrode assembly 22 and reduce the risk of damage to the electrode assembly 22.

[0138] The support portion 242 is a support block disposed on the side of the support plate 241 facing the wall portion 213 along the first direction. The support portion 242 is connected to the support plate 241 so that the relative position of the support portion 242 and the support plate 241 is relatively fixed, which helps to reduce the risk of the support plate 241 running off-center and enables the support plate 241 to stably support the electrode assembly 22.

[0139] The support plate 241 is disposed opposite to the wall portion 213 along the first direction, and the support portion 242 is disposed between the support plate 241 and the wall portion 213 along the first direction. The support portion 242 can support the support plate 241, so that there is a gap between the support plate 241 and the wall portion 213. The space between the support plate 241 and the wall portion 213 that is not occupied by the support portion 242 forms a clearance portion 243.

[0140] Optionally, there is a gap between the support plate 241 and the side wall 2111 of the housing 211, and the clearance part 243 connects the gap and the pressure relief mechanism 23. When the battery cell 20 is depressurized, the fluid medium inside the housing 21 can reach the pressure relief mechanism 23 through the gap and the clearance part 243 to achieve rapid pressure relief.

[0141] By providing a support portion 242 on the side of the support plate 241 facing the wall portion 213, the support portion 242 can support the support plate 241, so that there is a gap between the support plate 241 and the wall portion 213. The space between the support plate 241 and the wall portion 213 that is not occupied by the support portion 242 forms a clearance portion 243. This method is simple, convenient, easy to manufacture, and has a low cost.

[0142] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9In some embodiments, the support member 24 includes a plurality of support portions 242, which are spaced apart from the support plate 241.

[0143] The support member 24 may include two, three, four, or more support portions 242. The structures of the multiple support portions 242 may be identical or different. The multiple support portions 242 are spaced apart between the support plate 241 and the wall portion 213; optionally, the multiple support portions 242 are arranged in a matrix.

[0144] Please refer to Figure 5 In the embodiment shown in the figure, the support member 24 includes four support portions 242, which are generally distributed at the four corners of the support plate 241.

[0145] By providing multiple support portions 242, on the one hand, the support plate 241 can be better supported, allowing the support plate 241 to better support the electrode assembly 22 and reducing the risk of damage to the electrode assembly 22. On the other hand, the spaced-apart support portions 242 leave a large unoccupied space, resulting in a larger space for the clearance portion 243, which can better avoid the soldering portion 231 and better guide the fluid medium inside the casing 21 to the pressure relief mechanism 23 for pressure relief, which is beneficial to improving the life and reliability of the battery cell 20.

[0146] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 In some embodiments, there is a gap between the solder mark 231 and the support plate 241 along the first direction.

[0147] The solder mark 231 is located on the side of the support plate 241 away from the electrode assembly 22 along the first direction, and there is a gap between the solder mark 231 and the support plate 241 along the first direction, which can reduce the risk of interference between the solder mark 231 and the support plate 241.

[0148] By creating a gap between the solder joint 231 and the support plate 241, interference between them is less likely. This reduces the external force on the solder joint 231, lowering the risk of damage. Furthermore, the support plate 241 provides more stable support for the electrode assembly 22, further reducing the risk of damage and extending the lifespan of the battery cell 20.

[0149] Please refer to Figure 10 , Figure 10This is a schematic diagram of the structure of the support member 24 provided in some other embodiments of this application. In some other embodiments, the clearance portion 243 is a through hole provided in the support member 24, and the through hole penetrates two surfaces of the support member 24 that are disposed opposite to each other along a first direction.

[0150] The clearance portion 243 is a through hole that extends through two opposing surfaces of the support member 24 along the first direction. Optionally, the shape of the clearance portion 243 matches the outer contour of the pressure relief mechanism 23. For example, when the outer contour of the pressure relief mechanism 23 is racetrack-shaped, the clearance portion 243 can be a racetrack-shaped hole.

[0151] The clearance part 243 is a through hole provided in the support member 24, which can effectively avoid the soldering part 231, reduce the risk of interference between the soldering part 231 and the support member 24, and facilitate the flow of the fluid medium in the battery cell 20 to the pressure relief mechanism 23, which is beneficial to open the pressure relief mechanism 23 to relieve pressure when the pressure inside the battery cell 20 reaches the threshold.

[0152] Please refer to Figure 11 , Figure 11 This is a schematic diagram of the structure of the support member 24 provided in some embodiments of this application. In some embodiments, the support member 24 includes a first portion 244 and a second portion 245 that are separately disposed. Along a first direction, at least a portion of the first portion 244 and at least a portion of the second portion 245 are located between the electrode assembly 22 and the wall portion 213. Along a second direction, the first portion 244 and the second portion 245 are spaced apart, and the space between the first portion 244 and the second portion 245 forms a clearance portion 243. The second direction is perpendicular to the first direction.

[0153] Please refer to Figure 11 The second direction is the Y direction shown in the figure.

[0154] The support member 24 includes a first part 244 and a second part 245 that are separately arranged, and the first part 244 and the second part 245 are independent of each other and not connected to each other. The first part 244 and the second part 245 are spaced apart along a second direction. During manufacturing, the first part 244 and the second part 245 can be manufactured separately and then assembled to both ends of the soldering part 231 respectively.

[0155] Both the first portion 244 and the second portion 245 are made of insulating material and possess insulating properties. Along the first direction, the first portion 244 is partially or entirely located between the electrode assembly 22 and the wall portion 213 to insulate and isolate the electrode assembly 22 and the wall portion 213, reducing the risk of a short circuit between the electrode assembly 22 and the wall portion 213. Similarly, along the first direction, the second portion 245 is partially or entirely located between the electrode assembly 22 and the wall portion 213 to insulate and isolate the electrode assembly 22 and the wall portion 213, reducing the risk of a short circuit between the electrode assembly 22 and the wall portion 213.

[0156] Along the second direction, the first portion 244 and the second portion 245 are spaced apart, and the space between the first portion 244 and the second portion 245 forms a clearance portion 243 for avoiding the solder stamp portion 231.

[0157] The support member 24 includes a first part 244 and a second part 245 that are separately arranged, so that the space between the first part 244 and the second part 245 forms a clearance part 243. On the one hand, this effectively avoids the risk of interference between the soldering part 231 and the support member 24. On the other hand, it facilitates the flow of fluid medium inside the battery cell 20 to the pressure relief mechanism 23, making it less likely to affect the opening of the pressure relief mechanism 23, which is beneficial for the pressure relief mechanism 23 to open when the pressure inside the battery cell 20 reaches a threshold. Furthermore, during manufacturing, the first part 244 and the second part 245 can be manufactured separately and then placed on both sides of the soldering part 231, which simplifies manufacturing and reduces assembly difficulty.

[0158] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 In some embodiments, the solder stamp 231 does not contact the support member 24; and / or the solder stamp 231 does not contact the electrode assembly 22.

[0159] By preventing the solder joint 231 from contacting the support member 24, the risk of interference between the solder joint 231 and the support member 24 can be reduced. This reduces the external force on the solder joint 231, lowering the risk of damage. Furthermore, it allows the support member 24 to more stably support the electrode assembly 22, further reducing the risk of damage to the electrode assembly 22 and extending the lifespan of the battery cell 20.

[0160] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 In some embodiments, the wall portion 213 has a second surface 21331 facing the electrode assembly 22, and the second surface 21331 is provided with a mounting groove 2139. The bottom surface of the mounting groove 2139 is a first surface 2132, and the pressure relief mechanism 23 is at least partially accommodated within the mounting groove 2139.

[0161] The wall portion 213 has a second surface 21331 facing the electrode assembly 22. The second surface 21331 may be the surface of the wall portion 213 closest to the electrode assembly 22, or it may not be the surface of the wall portion 213 closest to the electrode assembly 22.

[0162] The mounting groove 2139 is a groove structure disposed on the second surface 21331. The mounting groove 2139 is recessed from the second surface 21331 in the direction from the electrode assembly 22 toward the wall portion 213. The bottom surface of the mounting groove 2139 is the first surface 2132, and the pressure relief hole 2131 is disposed on the bottom wall of the mounting groove 2139.

[0163] In some embodiments, a portion of the pressure relief mechanism 23 is housed within the mounting groove 2139, while another portion of the pressure relief mechanism 23 is located outside the mounting groove 2139. In other embodiments, the pressure relief mechanism 23 is completely housed within the mounting groove 2139.

[0164] In some embodiments, the profile shape of the sidewall of the mounting groove 2139 is the same as the outer profile shape of the pressure relief mechanism 23. The outer peripheral surface of the pressure relief mechanism 23 is welded to the side surface of the mounting groove 2139 to form a weld mark 231.

[0165] By providing a mounting groove 2139 on the second surface 21331 and accommodating at least a portion of the pressure relief mechanism 23 within the mounting groove 2139, the height of the pressure relief mechanism 23 extending beyond the second surface 21331 along the wall portion 213 towards the electrode assembly 22 is reduced. This reduces the risk of interference between the pressure relief mechanism 23 and other components, minimizes its impact on burst pressure, and improves the reliability of the battery cell 20. Furthermore, it reduces the space occupied by the pressure relief mechanism 23 within the battery cell 20, thereby increasing the energy density of the battery cell 20.

[0166] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 In some embodiments, the second surface 21331 is the surface of the wall portion 213 closest to the electrode assembly 22, the solder mark portion 231 protrudes from the second surface 21331, and the clearance portion 243 accommodates the portion of the solder mark portion 231 that protrudes from the second surface 21331.

[0167] The second surface 21331 is the surface of the wall portion 213 that is closest to the electrode assembly 22 along the first direction.

[0168] Please refer to Figure 6 , Figure 7 , Figure 8 and Figure 9 The second surface 21331 is provided with a mounting groove 2139, and the pressure relief mechanism 23 is completely accommodated within the mounting groove 2139. The surface of the pressure relief mechanism 23 closest to the electrode assembly 22 along the first direction is flush with the second surface 21331. The outer peripheral surface of the pressure relief mechanism 23 is welded to the side of the mounting groove 2139 to form a solder mark 231. The solder mark 231 protrudes from the second surface 21331 along the direction of the wall portion 213 towards the electrode assembly 22.

[0169] The clearance portion 243 can accommodate the portion of the solder stamp 231 that protrudes from the second surface 21331, so as to clear the solder stamp 231.

[0170] The solder mark 231 protrudes from the surface of the wall portion 213 closest to the electrode assembly 22, and the clearance portion 243 accommodates the portion of the solder mark 231 that protrudes from the surface of the wall portion 213 closest to the electrode assembly 22, so as to further reduce the risk of interference between the solder mark 231 and the support member 24.

[0171] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 In some embodiments, along a first direction, the wall portion 213 has a third surface 2134 facing the electrode assembly 22. The wall portion 213 includes a protrusion 2133, which at least partially protrudes from the third surface 2134 in the direction of the wall portion 213 toward the electrode assembly 22. The end face of the protrusion 2133 facing the electrode assembly 22 is a second surface 21331. The support member 24 abuts against the third surface 2134, and the clearance portion 243 accommodates at least a portion of the protrusion 2133.

[0172] The third surface 2134 is the surface of the wall portion 213 facing the electrode assembly 22 along the first direction. Optionally, the third surface 2134 is the inner surface of the wall portion 213.

[0173] The wall portion 213 includes a main body region 2136 and a protrusion 2133. The surface of the main body region 2136 facing the electrode assembly 22 along the first direction is a third surface 2134, and the protrusion 2133 at least partially protrudes from the third surface 2134. Optionally, the protrusion 2133 is an annular protrusion. The end face of the protrusion 2133 facing the electrode assembly 22 along the first direction is a second surface 21331, that is, the end face of the protrusion 2133 facing the electrode assembly 22 along the first direction is the surface of the wall portion 213 closest to the electrode assembly 22.

[0174] In some embodiments, the wall portion 213 includes a third surface 2134 and a fourth surface 2137, which are disposed opposite to each other along a first direction. The wall portion 213 is provided with a recess 2138, which is recessed from the fourth surface 2137 in a direction pointing from the fourth surface 2137 toward the third surface 2134, so that a protrusion 2133 at least partially protrudes from the third surface 2134 is formed at a position in the wall portion 213 corresponding to the recess 2138.

[0175] In some embodiments, the pressure relief mechanism 23 includes a pressure relief region 233, with a weak portion 232 surrounding the outer side of the pressure relief region 233. The pressure relief region 233 arches at least partially in a direction away from the electrode assembly 22. When the wall portion 213 is thin, a recess 2138 can be formed on the fourth surface 2137 of the wall portion 213 to correspond to a protrusion 2133 formed on the third surface 2134 of the wall portion 213. The pressure relief mechanism 23 is mounted on a mounting groove 2139 of the protrusion 2133, so that the pressure relief region 233 of the pressure relief mechanism 23 can arch outward using the space protruding inward from the protrusion 2133, thereby reducing the height by which the pressure relief region 233 protrudes from the fourth surface 2137 in the direction from the electrode assembly 22 toward the wall portion 213.

[0176] In an embodiment where the support member 24 includes a support plate 241 and a support portion 242, the support portion 242 abuts against the third surface 2134, and the side of the support plate 241 facing away from the wall portion 213 is supported on the electrode assembly 22.

[0177] In an embodiment where the support member 24 includes a first part 244 and a second part 245 that are separately arranged, one side of the first part 244 abuts against the third surface 2134 and the other side of the first part 244 is supported on the electrode assembly 22, one side of the second part 245 abuts against the third surface 2134 and the other side of the second part 245 is supported on the electrode assembly 22.

[0178] The clearance portion 243 accommodates part or all of the protrusion 2133 to avoid the protrusion 2133. Please refer to... Figure 6 and Figure 7 In the embodiment shown in the figure, the avoidance part 243 accommodates the entire protrusion 2133, and has a better avoidance effect on the protrusion 2133.

[0179] At least a portion of the protrusion 2133 protrudes from the third surface 2134 along the direction from the wall 213 toward the electrode assembly 22. A mounting groove 2139 is provided on the protrusion 2133 to accommodate at least a portion of the pressure relief mechanism 23. This helps to move the pressure relief mechanism 23 further away from the outer surface of the wall 213, thereby reducing the risk of the pressure relief mechanism 23 being subjected to external impacts and improving the reliability of the battery cell 20. The clearance portion 243 can avoid at least a portion of the protrusion 2133 to reduce the risk of interference between the protrusion 2133 and the support member 24, allowing the support member 24 to support the electrode assembly 22 more stably, thereby reducing the risk of damage to the electrode assembly 22 and extending the life of the battery cell 20.

[0180] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 In some embodiments, the wall portion 213 includes a main body region 2136 and an overlapping region 2135 that overlaps with the pressure relief mechanism 23 along a first direction. The surface of the overlapping region 2135 facing the electrode assembly 22 is a first surface 2132. A pressure relief hole 2131 is located in the overlapping region 2135, and the main body region 2136 is disposed around the overlapping region 2135. Along the first direction, the minimum thickness of the main body region 2136 is H1, and the minimum thickness of the overlapping region 2135 is H2, satisfying: 0.5 ≤ H2 / H1 ≤ 1.

[0181] The overlapping area 2135 is the portion of the wall 213 that overlaps with the pressure relief mechanism 23 along the first direction. Along the first direction, the overlapping area 2135 is located on the side of the pressure relief mechanism 23 facing away from the electrode assembly 22. The surface of the overlapping area 2135 facing the electrode assembly 22 is the first surface 2132, and the pressure relief mechanism 23 abuts against the first surface 2132. The overlapping area 2135 has an annular structure, and the central hole of the annular structure is the pressure relief hole 2131.

[0182] The main body area 2136 is the main part of the wall 213, and the main body area 2136 is arranged around the overlapping area 2135.

[0183] In an embodiment where the wall portion 213 includes a protrusion 2133, the protrusion 2133 includes an overlapping area 2135, which can be regarded as the bottom wall of the mounting groove 2139.

[0184] H1 represents the minimum thickness of the main body region 2136 along the first direction. Along the first direction, the main body region 2136 includes a third surface 2134 and a fourth surface 2137 disposed opposite to each other, wherein the third surface 2134 is the surface of the main body region 2136 closest to the electrode assembly 22, and the fourth surface 2137 is the surface of the main body region 2136 furthest from the electrode assembly 22. During measurement, the minimum distance between the third surface 2134 and the fourth surface 2137 along the first direction can be measured as H1.

[0185] H2 represents the minimum thickness of the overlap region 2135 along the first direction. Along the first direction, the overlap region 2135 includes a first surface 2132 and a fifth surface 21351 disposed opposite to each other, wherein the first surface 2132 faces the electrode assembly 22, and the fifth surface 21351 faces away from the electrode assembly 22. During measurement, the minimum distance between the first surface 2132 and the fifth surface 21351 along the first direction can be measured as H2.

[0186] H2 / H1 represents the ratio of the minimum thickness of the overlapping region 2135 along the first direction to the minimum thickness of the main body region 2136 along the first direction.

[0187] H2 / H1 can take values ​​of: 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, etc.

[0188] When H2 / H1 ≥ 0.5, the minimum thickness of the overlapping region 2135 is relatively large, giving it higher strength. This effectively supports the pressure relief mechanism 23, distributes the stress on the solder joint 231, reduces the risk of damage to the solder joint 231, and helps extend the lifespan of the battery cell 20. When H2 / H1 ≤ 1, the minimum thickness of the overlapping region 2135 is not too large. On the one hand, this helps reduce the risk of interference between the overlapping region 2135 and other components; on the other hand, it facilitates manufacturing and helps reduce manufacturing costs. Therefore, when 0.5 ≤ H2 / H1 ≤ 1, both the lifespan of the battery cell 20 and manufacturing costs can be balanced.

[0189] Optionally, 0.6 ≤ H2 / H1 ≤ 0.9.

[0190] H2 / H1 can take values ​​of: 0.6, 0.62, 0.65, 0.68, 0.7, 0.72, 0.75, 0.78, 0.8, 0.82, 0.85, 0.88, 0.9, etc.

[0191] When H2 / H1 ≥ 0.6, the minimum thickness of the overlapping region 2135 is greater, resulting in higher strength. This effectively supports the pressure relief mechanism 23, distributes the stress on the solder joint 231, reduces the risk of damage to the solder joint 231, and helps extend the lifespan of the battery cell 20. When H2 / H1 ≤ 0.9, the minimum thickness of the overlapping region 2135 is not too large. On the one hand, this helps reduce the risk of interference between the overlapping region 2135 and other components; on the other hand, it facilitates manufacturing and helps reduce manufacturing costs. Therefore, when 0.6 ≤ H2 / H1 ≤ 0.9, it is possible to better balance the lifespan of the battery cell 20 and manufacturing costs.

[0192] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 In some embodiments, the housing 21 includes a housing 211 and an end cap 212, the housing 211 having an opening and the end cap 212 closing the opening. The housing 211 includes a wall portion 213 disposed opposite to the end cap 212 along a first direction.

[0193] The housing 211 includes an integrally formed bottom wall 2112 and multiple side walls 2111. That is, the housing 211 is manufactured using an integral forming process, such as stamping, casting, or extrusion molding. In other words, the bottom wall 2112 and the multiple side walls 2111 are a single, integral structure. The multiple side walls 2111 form a cylindrical structure. One end of each side wall 2111 is connected to the bottom wall 2112, and the other ends of the side walls 2111 together form an opening. An end cap 212 is connected to the side walls 2111 and closes the opening.

[0194] "The housing 211 includes a wall portion 213, which is disposed opposite to the end cap 212 along the first direction." That is, the wall portion 213 is the bottom wall 2112 of the housing 211 that is disposed opposite to the end cap 212.

[0195] The wall portion 213 is the bottom wall 2112 of the housing 211, which is opposite to the end cap 212, and the pressure relief mechanism 23 is disposed on the bottom wall 2112. In this way, when the battery cell 20 is depressurized, the fluid medium inside the battery cell 20 can be ejected from the bottom of the battery cell 20, which helps to reduce the risk of personal injury caused by the fluid medium and improves the reliability of the battery cell 20.

[0196] This application embodiment also provides a battery device 100, which includes the aforementioned battery cell 20.

[0197] This application embodiment also provides an electrical device, which includes the aforementioned battery cell 20, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0198] According to some embodiments of this application, please refer to Figures 3-9 .

[0199] This application provides a battery cell 20, which includes an electrode assembly 22, a housing 21, a pressure relief mechanism 23, and a support member 24. The housing 21 houses the electrode assembly 22. The housing 21 has a wall portion 213, which is disposed opposite to the electrode assembly 22 along a first direction. The wall portion 213 has a first surface 2132 facing the electrode assembly 22 along the first direction, and a pressure relief hole 2131 is provided in the wall portion 213, one end of which extends to the first surface 2132. The pressure relief mechanism 23 abuts against the first surface 2132 and covers the pressure relief hole 2131, and the pressure relief mechanism 23 is welded to the wall portion 213 to form a solder mark portion 231. The support member 24 is at least partially disposed between the electrode assembly 22 and the wall portion 213 along the first direction, and the support member 24 supports the electrode assembly 22. The support member 24 has a clearance portion 243, which accommodates at least a portion of the solder mark portion 231. The wall portion 213 has a first surface 2132 facing the electrode assembly 22 along a first direction. The pressure relief mechanism 23 abuts against the first surface 2132 and covers the pressure relief hole 2131, that is, the pressure relief mechanism 23 is disposed on the side of the pressure relief hole 2131 facing the electrode assembly 22. The pressure relief mechanism 23 is welded to the wall portion 213 to form a solder mark 231. When the pressure relief mechanism 23 is subjected to pressure from inside the battery cell 20, since the pressure relief mechanism 23 abuts against the first surface 2132, the first surface 2132 can distribute the force, reducing the stress on the solder mark 231, thereby reducing the risk of damage to the solder mark 231 and extending the life of the battery cell 20. By providing a support member 24 to support the electrode assembly 22, the risk of interference between the electrode assembly 22 and other components is reduced, the stress on the electrode assembly 22 is reduced, thereby reducing the risk of damage to the electrode assembly 22 and extending the life of the battery cell 20. By providing a clearance portion 243 on the support member 24, the clearance portion 243 can avoid the solder stamp portion 231, thereby reducing the risk of interference between the solder stamp portion 231 and the support member 24. On the one hand, it can reduce the external force on the solder stamp portion 231 and reduce the risk of the solder stamp portion 231 being damaged. On the other hand, it can enable the support member 24 to support the electrode assembly 22 more stably, thereby reducing the risk of damage to the electrode assembly 22 and helping to extend the life of the battery cell 20.

[0200] The clearance portion 243 is an exhaust channel provided on the support member 24. The clearance portion 243 not only avoids the solder mark portion 231, but also serves as an exhaust channel. When the battery cell 20 is depressurized, the fluid medium inside the casing 21 can flow to the depressurization mechanism 23 through the exhaust channel to release pressure, reducing the risk of pressure buildup and improving the reliability of the battery cell 20.

[0201] The support member 24 includes a connected support plate 241 and a support portion 242. Along a first direction, the support plate 241 is disposed opposite to the wall portion 213, and the support portion 242 is disposed between the support plate 241 and the wall portion 213. The space between the support plate 241 and the wall portion 213 not occupied by the support portion 242 forms a clearance portion 243. By providing the support portion 242 on the side of the support plate 241 facing the wall portion 213, the support portion 242 can support the support plate 241, creating a gap between the support plate 241 and the wall portion 213. The space between the support plate 241 and the wall portion 213 not occupied by the support portion 242 forms the clearance portion 243. This design is simple, convenient, easy to manufacture, and has a low cost.

[0202] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: Electrode assembly; A housing for accommodating the electrode assembly, the housing having a wall portion disposed opposite to the electrode assembly along a first direction, the wall portion having a first surface facing the electrode assembly along the first direction, and the wall portion having a pressure relief hole, one end of the pressure relief hole extending to the first surface; A pressure relief mechanism abuts against the first surface and covers the pressure relief hole; the pressure relief mechanism is welded to the wall to form a weld mark. A support member is at least partially disposed between the electrode assembly and the wall portion along the first direction, the support member supports the electrode assembly, and the support member is provided with a clearance portion that accommodates at least a portion of the solder mark portion.

2. The battery cell according to claim 1, characterized in that, The clearance portion is an exhaust channel provided on the support member.

3. The battery cell according to claim 1, characterized in that, The support member includes a connected support plate and a support portion. Along the first direction, the support plate is disposed opposite to the wall portion, and the support portion is disposed between the support plate and the wall portion. The space between the support plate and the wall portion that is not occupied by the support portion forms the clearance portion.

4. The battery cell according to claim 3, characterized in that, The support member includes a plurality of support portions, which are spaced apart on the support plate.

5. The battery cell according to claim 3, characterized in that, Along the first direction, there is a gap between the solder mark and the support plate.

6. The battery cell according to claim 1, characterized in that, The clearance portion is a through hole provided in the support member, and the through hole penetrates two surfaces of the support member that are disposed opposite to each other along the first direction.

7. The battery cell according to claim 1, characterized in that, The support member includes a first part and a second part that are separately arranged. Along the first direction, at least a portion of the first part and at least a portion of the second part are located between the electrode assembly and the wall portion. Along the second direction, the first part and the second part are spaced apart, and the space between the first part and the second part forms the clearance portion, and the second direction is perpendicular to the first direction.

8. The battery cell according to claim 1, characterized in that, The solder mark does not contact the support member; and / or The solder mark is not in contact with the electrode assembly.

9. The battery cell according to any one of claims 1-8, characterized in that, The wall portion has a second surface facing the electrode assembly, the second surface being provided with a mounting groove, the bottom surface of the mounting groove being the first surface, and the pressure relief mechanism being at least partially accommodated within the mounting groove.

10. The battery cell according to claim 9, characterized in that, The second surface is the surface of the wall closest to the electrode assembly, the solder mark protrudes from the second surface, and the clearance portion accommodates the portion of the solder mark protruding from the second surface.

11. The battery cell according to claim 9, characterized in that, Along the first direction, the wall portion has a third surface facing the electrode assembly, the wall portion includes a protrusion, the protrusion at least partially protruding from the third surface in the direction of the wall portion toward the electrode assembly, the end face of the protrusion facing the electrode assembly is the second surface, the support abuts against the third surface, and the clearance portion accommodates at least a portion of the protrusion.

12. The battery cell according to any one of claims 1-8, characterized in that, The wall portion includes a main body area and an overlapping area that overlaps with the pressure relief mechanism along a first direction. The surface of the overlapping area facing the electrode assembly is the first surface. The pressure relief hole is located in the overlapping area. The main body area is arranged around the overlapping area. Along the first direction, the minimum thickness of the main body region is H1, and the minimum thickness of the overlapping region is H2, satisfying: 0.5≤H2 / H1≤1.

13. The battery cell according to claim 12, characterized in that, 0.6≤H2 / H1≤0.

9.

14. The battery cell according to any one of claims 1-8, characterized in that, The housing includes a shell and an end cap. The shell has an opening, and the end cap closes the opening. The shell includes a wall portion, which is disposed opposite to the end cap along the first direction.

15. A battery device, characterized in that, Includes the battery cell according to any one of claims 1-14.

16. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1-14, the battery cell being used to provide electrical energy to the electrical device.

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