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 a shell, an electrode assembly, a pressure relief mechanism and a current collecting member. The shell has a first wall, and the electrode assembly is accommodated in the shell. The electrode assembly comprises a main body and a first tab, and the first tab is arranged at one end of the main body facing the first wall in a first direction. The pressure relief mechanism is arranged on the first wall. The current collecting member comprises a current collecting body and a first protruding part. In the first direction, at least part of the current collecting body is arranged between the first wall and the first tab, and the current collecting body is connected with the first tab. The current collecting body has a first surface facing the first wall, and the first protruding part is arranged on the first surface. The first protruding part abuts against the first wall, and the first surface and the first wall form an exhaust gap leading to the pressure relief mechanism. The hardness of the current collecting body is greater than that of the first wall. The current collecting body is not easy to deform under the action of internal air pressure, which is beneficial to maintaining the exhaust gap and improving the reliability 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. Furthermore, battery reliability also needs to be considered. However, current battery reliability is relatively poor. 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 poor battery reliability in related technologies.

[0004] In a first aspect, embodiments of this application provide a battery cell, the battery cell including a casing, an electrode assembly, a pressure relief mechanism, and a current collector. The casing has a first wall; the electrode assembly is housed within the casing, the electrode assembly including a main body and a first tab, the first tab being disposed at one end of the main body facing the first wall along a first direction; the pressure relief mechanism is disposed on the first wall; the current collector includes a current collector body and a first protrusion, at least a portion of the current collector body being disposed between the first wall and the first tab along the first direction, the current collector body being connected to the first tab, the current collector body having a first surface facing the first wall, the first protrusion being disposed on the first surface, the first protrusion abutting against the first wall, and forming an exhaust gap between the first surface and the first wall leading to the pressure relief mechanism, the hardness of the current collector body being greater than the hardness of the first wall.

[0005] In the above technical solution, the current collector of the battery cell is provided with a first protrusion, which can directly or indirectly abut against the first wall, thereby forming an exhaust gap between the current collector body and the first wall leading to the pressure relief mechanism. By making the hardness of the current collector body greater than that of the first wall, the current collector body also has higher strength. This makes the current collector body less prone to deformation under the internal air pressure of the battery cell, thus maintaining the exhaust gap and reducing the risk of the current collector body blocking the pressure relief mechanism. When the battery cell is depressurized, the emissions from the battery cell can flow to the pressure relief mechanism through the exhaust gap, facilitating smooth pressure relief and improving the reliability of the battery cell.

[0006] As an optional technical solution in this application embodiment, the Vickers hardness of the current collection body is A1, and the Vickers hardness of the first wall is A2, satisfying: 1.2≤A1 / A2≤1.8.

[0007] In the above technical solution, when A1 / A2 ≥ 1.2, the Vickers hardness of the current collector is relatively high, and the current collector also has correspondingly high strength. This makes the current collector less prone to deformation under the internal gas pressure of the battery cell, thus helping to maintain the exhaust gap, reducing the risk of the current collector blocking the pressure relief mechanism, and improving the reliability of the battery cell. When A1 / A2 ≤ 1.8, the Vickers hardness of the current collector is not too high, thus facilitating processing and manufacturing, and helping to reduce the manufacturing cost of the battery cell. Therefore, when 1.2 ≤ A1 / A2 ≤ 1.8, both the reliability of the battery cell can be improved and the manufacturing cost is relatively low.

[0008] As an optional technical solution in this application embodiment, 1.3≤A1 / A2≤1.6.

[0009] In the above technical solution, when A1 / A2 ≥ 1.3, the Vickers hardness of the current collector is greater, and the current collector also has higher strength. This makes the current collector less prone to deformation under the internal gas pressure of the battery cell, thus better maintaining the exhaust gap and further reducing the risk of the current collector blocking the pressure relief mechanism, which is beneficial to improving the reliability of the battery cell. When A1 / A2 ≤ 1.6, the Vickers hardness of the current collector is not too high, which facilitates processing and manufacturing, and helps to reduce the manufacturing cost of the battery cell. Therefore, when 1.3 ≤ A1 / A2 ≤ 1.6, both the reliability of the battery cell can be improved and the manufacturing cost is lower.

[0010] As an optional technical solution in this application embodiment, the Vickers hardness of the current collector body is A1, which satisfies: 110HV≤A1≤150HV.

[0011] In the above technical solution, when A1 ≥ 110 HV, the Vickers hardness of the current collector is relatively high, and the current collector also has correspondingly high strength. This makes the current collector less prone to deformation under the internal gas pressure of the battery cell, thus helping to maintain the exhaust gap, reducing the risk of the current collector blocking the pressure relief mechanism, and improving the reliability of the battery cell. When A1 ≤ 150 HV, the Vickers hardness of the current collector is not too high, thus facilitating processing and manufacturing, and helping to reduce the manufacturing cost of the battery cell. Therefore, when 110 HV ≤ A1 ≤ 150 HV, both the reliability of the battery cell can be improved and the manufacturing cost is relatively low.

[0012] As an optional technical solution in this application embodiment, 120HV≤A1≤140HV.

[0013] In the above technical solution, when A1 ≥ 120 HV, the Vickers hardness of the current collector is greater, and the current collector also has higher strength. This makes the current collector less prone to deformation under the internal gas pressure of the battery cell, thus better maintaining the venting gap and further reducing the risk of the current collector blocking the pressure relief mechanism, which is beneficial to improving the reliability of the battery cell. When A1 ≤ 140 HV, the Vickers hardness of the current collector is not too high, which facilitates processing and manufacturing, and helps to reduce the manufacturing cost of the battery cell. Therefore, when 120 HV ≤ A1 ≤ 140 HV, both the reliability of the battery cell can be improved and the manufacturing cost is lower.

[0014] As an optional technical solution in this application embodiment, along the first direction, the first wall has a second surface facing the electrode assembly, and the exhaust gap is formed between the second surface and the first surface. A second protrusion is provided on the second surface, and the second protrusion is disposed opposite to the current collecting body. The hardness of the second protrusion is greater than the hardness of the first wall.

[0015] In the above technical solution, by providing a second protrusion on the second surface, if the second protrusion is spaced apart from the current collector body, when the battery cell is depressurized, even if the current collector body deforms towards the first wall under the internal pressure of the battery cell, the second protrusion can still abut against the space between the first and second surfaces, ensuring a gap between the current collector body and the first wall. This facilitates the flow of effluent from the battery cell to the depressurization mechanism, promoting smooth depressurization and improving the reliability of the battery cell. If the second protrusion abuts against the current collector body, it can prevent the current collector body from deforming towards the first wall, maintaining the exhaust gap and promoting smooth depressurization of the battery cell, thus improving the reliability of the battery cell.

[0016] As an optional technical solution in this application embodiment, the second protrusion is separately disposed from and connected to the first wall.

[0017] In the above technical solution, when the second protrusion and the first wall are separately configured and connected, the second protrusion and the first wall can be made of different materials so that the hardness of the second protrusion is greater than that of the first protrusion. Furthermore, the second protrusion and the first wall can be manufactured separately and then connected together, making processing and manufacturing relatively convenient.

[0018] As an optional technical solution in this application embodiment, the first wall has a third surface facing away from the electrode assembly, the first wall is provided with a first groove, the first groove is recessed from the third surface in a direction pointing from the third surface to the second surface, and a second protrusion protruding from the second surface is formed at a position corresponding to the first groove on the first wall.

[0019] In the above technical solution, during the forming process, a first groove can be formed on the third surface by stamping, thereby forming a second protrusion protruding from the second surface. The forming method of the second protrusion is simple. Furthermore, by stamping the first groove, the groove wall of the first groove will undergo work hardening (the grain arrangement changes, resulting in lattice distortion, which reduces the plasticity of the metal and increases the hardness of the material), thus making the hardness of the formed second protrusion greater than the hardness of the first wall.

[0020] As an optional technical solution in this application embodiment, the surface of the second protrusion is provided with an anti-corrosion layer and / or a wear-resistant layer.

[0021] In the above technical solution, by providing an anti-corrosion layer on the surface of the second protrusion, the risk of electrochemical corrosion of the second protrusion is reduced, and the height of the second protrusion above the second surface is maintained, thereby helping to maintain the exhaust clearance. Under vibration conditions, the current collector may be subjected to the action of the electrode assembly and come into contact with the second protrusion. By providing a wear-resistant layer on the surface of the second protrusion, the risk of wear on the second protrusion is reduced. On the one hand, this helps to maintain the height of the second protrusion above the second surface, thereby helping to maintain the exhaust clearance; on the other hand, it helps to reduce the risk of metal debris generated by the wear of the second protrusion falling into the electrode assembly and causing a short circuit.

[0022] As an optional technical solution in this application embodiment, the first wall is provided with a through hole, a part of the first protrusion extends out of the through hole along the direction of the electrode assembly pointing to the first wall, and forms the electrode lead-out part of the battery cell, and the first protrusion is insulated from the first wall.

[0023] In the above technical solution, the first protrusion serves as the electrode lead-out portion of the battery cell. The first protrusion can output or input electrical energy into the battery cell. The first protrusion can also serve as a limiting structure to restrict the current collector from moving toward the first wall, thereby forming an exhaust gap between the current collector and the first surface leading to the pressure relief mechanism. The first protrusion can also serve as the electrode lead-out portion of the battery cell. One structure realizes multiple functions, which helps to simplify the structure of the battery cell and reduce the cost of the battery cell.

[0024] As an optional technical solution in this application embodiment, the first wall is provided with a through hole, and the first protrusion passes through the through hole and is welded to the first wall.

[0025] In the above technical solution, the first protrusion passes through the through hole. On the one hand, the through hole can position the first protrusion, thus facilitating welding. On the other hand, the first protrusion and the first wall can be welded from the outside of the outer casing, which simplifies the operation and improves the welding quality. When the first protrusion is welded to the first wall, the first wall serves as the electrode lead-out part of the battery cell, and the first wall can output electrical energy to or input electrical energy to the battery cell.

[0026] As an optional technical solution in this application embodiment, the first protrusion is welded to the first wall to form a weld mark, the pressure relief mechanism is separately disposed from the first wall, the first wall is provided with a pressure relief hole, and the pressure relief mechanism is welded to the first wall and covers the pressure relief hole; the minimum distance between the weld mark and the pressure relief mechanism is L, which satisfies: 1.5mm≤L≤15mm.

[0027] In the above technical solution, when L ≥ 1.5 mm, the minimum distance between the soldered part and the pressure relief mechanism is relatively large. When the first protrusion is welded to the first wall, the heat from the welding is less likely to affect the weld strength between the pressure relief mechanism and the first wall, nor is it likely to affect the burst pressure of the pressure relief mechanism, which is beneficial to improving the reliability of the battery cell. When L ≤ 15 mm, the minimum distance between the soldered part and the pressure relief mechanism is not too large, which is beneficial to making full use of the space of the battery cell and reducing the risk of interference with other components. Therefore, when 1.5 mm ≤ L ≤ 15 mm, it can both improve the reliability of the battery cell and make full use of the space of the battery cell, reducing the risk of interference with other components.

[0028] As an optional technical solution in this application embodiment, the first protrusion and the current collection body are integrally formed.

[0029] In the above technical solution, when the first protrusion and the current collector body are integrally formed, the integrity of the first protrusion and the current collector body is better, the connection strength between the first protrusion and the current collector body is higher, and the connection position between the first protrusion and the current collector body is not easily deformed or damaged. This is conducive to maintaining the exhaust gap between the current collector body and the first wall, thereby facilitating smooth pressure release of the battery cell and improving the reliability of the battery cell.

[0030] Secondly, embodiments of this application also provide a battery device, which includes the aforementioned battery cell.

[0031] 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

[0032] 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.

[0033] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0034] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0035] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0036] Figure 4 Exploded views of a single battery cell provided in some embodiments of this application;

[0037] Figure 5 This application provides a schematic diagram of the connection between the first wall and the flow collection component in some embodiments;

[0038] Figure 6 A side view schematic diagram of the connection between the first wall and the flow collection member provided for some embodiments of this application;

[0039] Figure 7 A schematic diagram of the structure of the current collector component on the side away from the electrode assembly provided in some embodiments of this application;

[0040] Figure 8 A schematic diagram of the structure of the side of the first wall facing away from the electrode assembly provided in some embodiments of this application;

[0041] Figure 9 A schematic diagram of the structure of the first wall facing the electrode assembly, provided for some embodiments of this application;

[0042] Figure 10 A cross-sectional view of the second protrusion provided in some embodiments of this application;

[0043] Figure 11 A cross-sectional view of the second protrusion provided in some other embodiments of this application;

[0044] Figure 12 This is a top view schematic diagram of the connection between the first wall and the flow collection member provided for 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; 212-End cap; 213-First wall; 2131-Through hole; 2132-Second surface; 2133-Second protrusion; 2134-Pressure relief hole; 2135-Third surface; 2136-First groove; 2137-Anti-corrosion layer; 2138-Wear-resistant layer; 2139-Fourth surface; 214 - Exhaust gap; 22- Electrode assembly; 231- Main body; 232- First tab; 23- Pressure relief mechanism; 24- Current collector; 241- Current collector body; 2411- First surface; 242- First protrusion; 2421- First part; 2422- Second part; 2423- Transition part; 243- Soldering part; 25- Liquid injection hole; 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 0.05At 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 component 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 individual battery cell assemblies housed within the housing.

[0089] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the 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, battery reliability must also be considered. However, current battery reliability is relatively poor.

[0097] To improve the reliability of individual battery cells, existing technologies include installing a pressure relief mechanism on the outer casing of the battery cell. When the internal pressure of the battery cell reaches the burst pressure, the pressure relief mechanism opens to release the internal pressure of the battery cell, thereby reducing the risk of battery cell explosion and fire.

[0098] However, in related technologies, a current collector is connected between the wall of the casing where the pressure relief mechanism is located and the electrode assembly. When a battery cell experiences thermal runaway, the current collector is easily pressed against the wall of the casing where the pressure relief mechanism is located under the pressure inside the battery cell, thereby blocking the pressure relief mechanism. The pressure relief mechanism cannot release pressure normally, resulting in poor reliability of the battery cell.

[0099] In view of this, embodiments of this application provide a battery cell, which includes a casing, an electrode assembly, a pressure relief mechanism, and a current collector. The casing has a first wall, and the electrode assembly is housed within the casing. The electrode assembly includes a main body and a first tab, the first tab being disposed at one end of the main body facing the first wall along a first direction. The pressure relief mechanism is disposed on the first wall. The current collector includes a current collector body and a first protrusion, at least a portion of which is disposed between the first wall and the first tab along the first direction, and the current collector body is connected to the first tab. The current collector body has a first surface facing the first wall, and the first protrusion is disposed on the first surface. The first protrusion abuts against the first wall, forming a venting gap between the first surface and the first wall leading to the pressure relief mechanism. The hardness of the current collector body is greater than the hardness of the first wall.

[0100] The current collector of the battery cell has a first protrusion that can directly or indirectly abut against the first wall, thereby creating an exhaust gap between the current collector body and the first wall, leading to the pressure relief mechanism. By making the hardness of the current collector body greater than that of the first wall, the current collector body also has higher strength. This makes the current collector body less prone to deformation under the internal pressure of the battery cell, thus maintaining the exhaust gap and reducing the risk of the current collector body blocking the pressure relief mechanism. When the battery cell is depressurized, the emissions from the battery cell can flow to the pressure relief mechanism through the exhaust gap, facilitating smooth pressure relief and improving the reliability of the battery cell.

[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 1This 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 and Figure 8 , 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 This is a schematic diagram of the connection between the first wall 213 and the flow collection member 24 provided for some embodiments of this application. Figure 6 This is a side view schematic diagram showing the connection between the first wall 213 and the flow collection member 24, provided for some embodiments of this application. Figure 7 This is a schematic diagram of the structure of the current collector 24 on the side opposite to the electrode assembly 22, provided in some embodiments of this application. Figure 8 This is a schematic diagram of the structure of the first wall 213 facing away from the electrode assembly 22, provided in some embodiments of this application. Embodiments of this application provide a battery cell 20, which includes a housing 21, an electrode assembly 22, a pressure relief mechanism 23, and a current collector 24. The housing 21 has a first wall 213, and the electrode assembly 22 is housed within the housing 21. The electrode assembly 22 includes a main body 231 and a first tab 232, the first tab 232 being disposed at the end of the main body 231 facing the first wall 213 along a first direction. The pressure relief mechanism 23 is disposed on the first wall 213. The current collector 24 includes a current collector body 241 and a first protrusion 242. Along the first direction, at least a portion of the current collector body 241 is disposed between the first wall 213 and the first tab 232, and the current collector body 241 is connected to the first tab 232. The current collector body 241 has a first surface 2411 facing the first wall 213, and the first protrusion 242 is disposed on the first surface 2411. The first protrusion 242 abuts against the first wall 213, forming an exhaust gap 214 between the first surface 2411 and the first wall 213, leading to the pressure relief mechanism 23. The hardness of the collector body 241 is greater than that of the first wall 213.

[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 less prone to deformation under pressure and impact, enabling battery cell 20 to have 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, and plastic.

[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 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 231 of the electrode assembly 22, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body 231 or separately at both ends of the main body 231. During the charging and discharging process of the battery cell 20, the positive and negative active materials react with the electrolyte.

[0117] Please refer to Figure 3 and Figure 4 The first direction is the X direction shown in the figure. Along the first direction, the first electrode tab 232 is disposed at the end of the main body 231 facing the first wall 213. The first electrode tab 232 can be the positive electrode tab described above, or the first electrode tab 232 can be the negative electrode tab described above.

[0118] The first wall 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 first wall 213 is an end cap 212. In other embodiments, the first wall 213 is a bottom wall of the housing 211 opposite to the end cap 212. In still other embodiments, the housing 211 includes a side wall, and the first wall 213 is a portion of the side wall.

[0119] exist Figure 3 and Figure 4 In the illustrated embodiment, the battery cell 20 is a cylindrical battery cell. The first wall 213 is located at one end of the electrode assembly 22 along a first direction. In embodiments where the housing 211 has an opening at only one end, the first wall 213 can be an end cap 212 or a wall portion of the housing 211 opposite to the end cap 212. In embodiments where both opposite ends of the housing 211 have openings, one of the two end caps 212 serves as the first wall 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 a predetermined value, thereby releasing the internal pressure of the battery cell 20. The pressure relief mechanism 23 can be a component mounted on the first wall 213, in which case the pressure relief mechanism 23 is separately configured and connected to the first wall 213. For example, the pressure relief mechanism 23 is an explosion-proof plate mounted on the first wall 213. Alternatively, the pressure relief mechanism 23 can be part of the first wall 213, in which case the pressure relief mechanism 23 is integrally formed with the first wall 213.

[0121] The pressure relief mechanism 23 includes a weak portion that 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 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 may be lower than the strength at other locations, so that when the internal pressure or temperature of the battery cell 20 reaches the predetermined value, the weak portion can crack under the internal pressure to release the internal pressure of the battery cell 20. In other embodiments, the melting point of the pressure relief mechanism 23 at the weak portion may be lower than the melting point at other locations. Thus, when the internal pressure or temperature of the battery cell 20 reaches the predetermined value, the weak portion can crack under the high temperature to release the internal pressure of the battery cell 20.

[0122] The current collector 24 is a conductive element electrically connected to the electrode assembly 22. In some embodiments, the current collector 24 is electrically connected to the electrode assembly 22 and the first wall 213 to output electrical energy from the battery cell 20 or input electrical energy to the battery cell 20 through the first wall 213. In other embodiments, the current collector 24 is electrically connected to the electrode assembly 22 and the electrode terminals to output electrical energy from the battery cell 20 or input electrical energy to the battery cell 20 through the electrode terminals. In still other embodiments, the current collector 24 extends at least partially beyond the housing 21 to output electrical energy from the battery cell 20 or input electrical energy to the battery cell 20 through the current collector 24.

[0123] The current collector body 241 is the main part of the current collector component 24 that enables it to perform its function. The current collector body 241 is located inside the housing 21 and is positioned between the first wall 213 and the electrode assembly 22 along the first direction. The current collector body 241 is electrically connected to the electrode assembly 22. For example, the current collector body 241 can be welded to the first tab 232 of the electrode assembly 22 to achieve electrical connection between the current collector body 241 and the electrode assembly 22.

[0124] Please refer to Figure 7 In the embodiment shown in the figure, the current collection body 241 is in the shape of a disk.

[0125] The first surface 2411 is the surface of the current collector 241 facing the first wall 213 along the first direction. The first protrusion 242 is a protruding structure that protrudes from the first surface 2411 and is a conductive element. The first protrusion 242 and the current collector 241 can be integrally formed, or the first protrusion 242 and the current collector 241 can be separately arranged and connected.

[0126] After the first protrusion 242 directly or indirectly abuts against the first wall 213, the first protrusion 242 and the first wall 213 can be electrically connected or insulated. If the first protrusion 242 directly abuts against the first wall 213, making direct contact between the first protrusion 242 and the first wall 213, then the first protrusion 242 and the first wall 213 are electrically connected, and the current collector 24 is electrically connected to the first wall 213 and the electrode assembly 22. If the first protrusion 242 indirectly abuts against the first wall 213, an intermediate member is provided between the first protrusion 242 and the first wall 213. This intermediate member can be an insulating member or a conductive member. Taking an insulating member as an example, the first protrusion 242 can indirectly abut against the first wall 213 through an insulating member. In this case, the first protrusion 242 and the first wall 213 are insulated. Taking the intermediate component as a conductive component as an example, the first protrusion 242 can indirectly abut against the first wall 213 through the conductive component. At this time, the first protrusion 242 and the first wall 213 are electrically connected, and the current collector 24 is electrically connected to the first wall 213 and the electrode assembly 22.

[0127] Please refer to Figure 5 , Figure 6 , Figure 7 and Figure 8 In some embodiments, the first wall 213 is provided with a through hole 2131, and at least a portion of the first protrusion 242 is inserted into the through hole 2131 and positioned in conjunction with the through hole 2131. The positioning and engagement of the first protrusion 242 with the through hole 2131 facilitates the assembly of the first wall 213 and the current collector 24, and also limits the current collector 24, reducing the risk of the current collector 24 deviating from its original position. This helps maintain the exhaust gap 214 between the current collector body 241 and the first wall 213, thereby facilitating smooth pressure release of the battery cell 20 and improving the reliability of the battery cell 20.

[0128] In some embodiments, the first protrusion 242 includes a first portion 2421 and a second portion 2422, wherein the first portion 2421 is closer to the current collector body 241 than the second portion 2422. Along a direction perpendicular to the first direction, the first portion 2421 extends beyond the outer peripheral surface of the second portion 2422, and at least a portion of the second portion 2422 is inserted into the through hole 2131, forming a positioning engagement with the through hole 2131. Along the first direction, the first portion 2421 directly or indirectly abuts against the first wall 213. At least a portion of the second portion 2422 is inserted into the recess, thereby facilitating a positioning engagement with the recess. The direct or indirect abutment of the first portion 2421 against the first wall 213 makes it less likely that the current collector body 241 will abut against the first wall 213 under the influence of internal air pressure in the battery cell 20, and the current collector body 241 is less likely to block the pressure relief mechanism 23 disposed on the first wall 213, which facilitates smooth pressure relief in the battery cell 20, thereby improving the reliability of the battery cell 20.

[0129] In some embodiments, the first protrusion 242 further includes a transition portion 2423, which connects the first portion 2421 and the second portion 2422. The outer surface of the transition portion 2423 connects the outer peripheral surface of the second portion 2422 and the surface of the first portion 2421 facing away from the current collecting body 241. The first portion 2421 abuts against the first wall 213 through the transition portion 2423. This abutment of the first portion 2421 against the first wall 213 through the transition portion 2423 helps to reduce the gap between the outer peripheral surface of the first portion 2421 and the wall surface of the through hole 2131, thus improving the positioning effect. Furthermore, if the first portion 2421 is welded to the first wall 213, a smaller gap between the outer peripheral surface of the first portion 2421 and the wall surface of the through hole 2131 helps to improve the connection quality.

[0130] In other embodiments, the second portion 2422 is connected to the surface of the first portion 2421 that faces away from the current collector 241, or is further away from the current collector 241 than the surface of the first portion 2421 that faces away from the current collector 241. The surface of the first portion 2421 that faces away from the current collector 241 directly abuts against the first wall 213. The large contact area between the surface of the first portion 2421 that faces away from the current collector 241 and the first wall 213 is beneficial for dispersing stress and reducing the risk of stress concentration.

[0131] Please refer to Figure 5 , Figure 6 , Figure 7 and Figure 8 In some embodiments, the orthographic projection of the pressure relief mechanism 23 and the orthographic projection of the first protrusion 242 do not overlap in the projection plane perpendicular to the first direction. Since the orthographic projections of the pressure relief mechanism 23 and the first protrusion 242 do not overlap in the projection plane perpendicular to the first direction, the first protrusion 242 is less likely to obstruct the opening of the pressure relief mechanism 23 when the battery cell 20 is depressurized, which facilitates smooth pressure relief of the battery cell 20 and improves the reliability of the battery cell 20.

[0132] The first protrusion 242 directly or indirectly abuts against the first wall 213, which allows the first wall 213 and the current collector 241 to be spaced apart, so that an exhaust gap 214 leading to the pressure relief mechanism 23 is formed between the first wall 213 and the current collector 241. Furthermore, due to the presence of the first protrusion 242, the current collector 241 is less likely to abut against the first wall 213 under the action of the internal air pressure of the battery cell 20, and the current collector 241 is less likely to block the pressure relief mechanism 23 provided on the first wall 213.

[0133] Hardness refers to a material's ability to resist indentation by a hard object. Different testing methods exist, resulting in different hardness standards, such as Rockwell hardness, Brinell hardness, and Vickers hardness. "The hardness of the manifold body 241 is greater than the hardness of the first wall 213" can mean: the Rockwell hardness of the manifold body 241 is greater than the Rockwell hardness of the first wall 213; the Brinell hardness of the manifold body 241 is greater than the Brinell hardness of the first wall 213; or the Vickers hardness of the manifold body 241 is greater than the Vickers hardness of the first wall 213.

[0134] Taking Vickers hardness as an example, Vickers hardness refers to the process of pressing a diamond pyramid indenter with a 136-degree angle between its opposite faces into the surface of the test sample under a specified load. After holding the indenter for a certain period of time, the load is removed, the diagonal length of the indentation is measured, and the surface area of ​​the indentation is calculated. Finally, the average pressure on the surface area of ​​the indentation is calculated, which is the Vickers hardness value of the metal, represented by the symbol HV. In actual measurement, calculation is not required; instead, the hardness value is obtained directly from a table based on the measured diagonal length of the indentation.

[0135] The current collector 24 of the battery cell 20 has a first protrusion 242 that can directly or indirectly abut against the first wall 213, thereby forming an exhaust gap 214 between the current collector body 241 of the current collector 24 and the first wall 213, leading to the pressure relief mechanism 23. By making the hardness of the current collector body 241 greater than that of the first wall 213, the current collector body 241 also has higher strength. This makes the current collector body 241 less prone to deformation under the internal air pressure of the battery cell 20, thus maintaining the exhaust gap 214 and reducing the risk of the current collector body 241 blocking the pressure relief mechanism 23. When the battery cell 20 is depressurized, the emissions from the battery cell 20 can flow to the pressure relief mechanism 23 through the exhaust gap 214, facilitating smooth pressure relief of the battery cell 20 and improving its reliability.

[0136] In some embodiments, the Vickers hardness of the current collector 241 is A1, and the Vickers hardness of the first wall 213 is A2, satisfying: 1.2≤A1 / A2≤1.8.

[0137] A1 represents the Vickers hardness of the manifold body 241. A2 represents the Vickers hardness of the first wall 213. A1 / A2 represents the ratio of the Vickers hardness of the manifold body 241 to the Vickers hardness of the first wall 213.

[0138] A1 / A2 can be 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, etc.

[0139] When A1 / A2 ≥ 1.2, the Vickers hardness of the current collector 241 is relatively high, and the current collector 241 also has higher strength. This makes the current collector 241 less prone to deformation under the internal air pressure of the battery cell 20, which helps maintain the exhaust gap 214, reduces the risk of the current collector 241 blocking the pressure relief mechanism 23, and improves the reliability of the battery cell 20. When A1 / A2 ≤ 1.8, the Vickers hardness of the current collector 241 is not too high, which facilitates processing and manufacturing, and helps reduce the manufacturing cost of the battery cell 20. Therefore, when 1.2 ≤ A1 / A2 ≤ 1.8, both the reliability of the battery cell 20 can be improved and the manufacturing cost is lower.

[0140] Optionally, 1.3 ≤ A1 / A2 ≤ 1.6.

[0141] A1 / A2 can be 1.3, 1.32, 1.35, 1.38, 1.4, 1.42, 1.45, 1.48, 1.5, 1.52, 1.55, 1.58, 1.6, etc.

[0142] When A1 / A2 ≥ 1.3, the Vickers hardness of the current collector 241 is greater, and the current collector 241 also has higher strength. This makes the current collector 241 less prone to deformation under the internal air pressure of the battery cell 20, which is more conducive to maintaining the exhaust gap 214 and further reduces the risk of the current collector 241 blocking the pressure relief mechanism 23, thus improving the reliability of the battery cell 20. When A1 / A2 ≤ 1.6, the Vickers hardness of the current collector 241 is not too high, which facilitates processing and manufacturing and helps to reduce the manufacturing cost of the battery cell 20. Therefore, when 1.3 ≤ A1 / A2 ≤ 1.6, both the reliability of the battery cell 20 can be improved and the manufacturing cost is lower.

[0143] In some embodiments, the Vickers hardness of the current collector 241 is A1, satisfying: 110HV≤A1≤150HV.

[0144] The Vickers hardness of the current collector 241 is 110-150.

[0145] The Vickers hardness of the current collector 241 can be 110HV, 115HV, 120HV, 125HV, 130HV, 135HV, 140HV, 145HV, 150HV, etc.

[0146] When A1 ≥ 110 HV, the Vickers hardness of the current collector 241 is relatively high, and the current collector 241 also has correspondingly high strength. This makes the current collector 241 less prone to deformation under the internal air pressure of the battery cell 20, thus helping to maintain the exhaust gap 214, reducing the risk of the current collector 241 blocking the pressure relief mechanism 23, and improving the reliability of the battery cell 20. When A1 ≤ 150 HV, the Vickers hardness of the current collector 241 is not too high, thus facilitating processing and manufacturing, and helping to reduce the manufacturing cost of the battery cell 20. Therefore, when 110 HV ≤ A1 ≤ 150 HV, both the reliability of the battery cell 20 can be improved and the manufacturing cost can be lower.

[0147] Optionally, 120HV≤A1≤140HV.

[0148] The Vickers hardness of the current collector 241 can be 120HV, 122HV, 125HV, 128HV, 130HV, 132HV, 135HV, 138HV, 140HV, etc.

[0149] When A1 ≥ 120 HV, the Vickers hardness of the current collector 241 is greater, and the current collector 241 also has higher strength. This makes the current collector 241 less prone to deformation under the internal air pressure of the battery cell 20, which is more conducive to maintaining the exhaust gap 214 and further reduces the risk of the current collector 241 blocking the pressure relief mechanism 23, thus improving the reliability of the battery cell 20. When A1 ≤ 140 HV, the Vickers hardness of the current collector 241 is not too high, which facilitates processing and manufacturing and helps to reduce the manufacturing cost of the battery cell 20. Therefore, when 120 HV ≤ A1 ≤ 140 HV, the reliability of the battery cell 20 can be improved while maintaining a lower manufacturing cost.

[0150] Please refer to Figure 5 , Figure 6 , Figure 7 and Figure 8 In some embodiments, the size of the exhaust gap 214 along the first direction is H, which satisfies: 0.6mm≤H≤1.5mm.

[0151] H represents the dimension of the exhaust gap 214 along the first direction. The dimension of the exhaust gap 214 along the first direction can be the same at multiple different positions, or the dimension of the exhaust gap 214 along the first direction can vary at multiple different positions. In this case, the minimum dimension of the exhaust gap 214 along the first direction is greater than or equal to 0.6 mm, and the maximum dimension of the exhaust gap 214 along the first direction is less than or equal to 1.5 mm.

[0152] H can be 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, etc.

[0153] When H ≥ 0.6 mm, the exhaust gap 214 has a relatively large dimension along the first direction, which facilitates the flow of effluent from the battery cell 20 to the pressure relief mechanism 23, promoting smooth pressure relief in the battery cell 20 and improving its reliability. When H ≤ 1.5 mm, the exhaust gap 214 is not too large along the first direction, reducing its impact on the internal space of the battery cell 20 and improving its energy density. Therefore, when 0.6 mm ≤ H ≤ 1.5 mm, both the reliability and energy density of the battery cell 20 can be balanced.

[0154] Please refer to Figure 9 , Figure 9 This is a schematic diagram of the structure of the first wall 213 facing the electrode assembly 22 according to some embodiments of this application. In some embodiments, along a first direction, the first wall 213 has a second surface 2132 facing the electrode assembly 22, and an exhaust gap 214 is formed between the second surface 2132 and the first surface 2411. A second protrusion 2133 is provided on the second surface 2132, and the second protrusion 2133 is disposed opposite to the current collecting body 241. The hardness of the second protrusion 2133 is greater than the hardness of the first wall 213.

[0155] The second surface 2132 is the surface of the first wall 213 facing the electrode assembly 22 along the first direction. Along the first direction, the first surface 2411 and the second surface 2132 are disposed opposite to each other, and an exhaust gap 214 leading to the pressure relief mechanism 23 is formed between the first surface 2411 and the second surface 2132.

[0156] The second protrusion 2133 is a protruding structure that protrudes from the second surface 2132. The second protrusion 2133 and the first wall 213 can be integrally formed, or they can be separately arranged and connected. Along the first direction, the second protrusion 2133 is arranged opposite to the current collector 241. The second protrusion 2133 can contact the current collector 241, or it can have a gap with the current collector 241. If the second protrusion 2133 is spaced apart from the current collector 241, when the battery cell 20 is depressurized, even if the current collector 241 deforms towards the first wall 213 under the internal pressure of the battery cell 20, the second protrusion 2133 can still abut against the space between the first surface 2411 and the second surface 2132, so that there is still a gap between the current collector 241 and the first wall 213. If the second protrusion 2133 abuts against the collector body 241, the second protrusion 2133 can prevent the collector body 241 from deforming toward the first wall 213, so as to maintain the exhaust gap 214.

[0157] In the projection plane perpendicular to the first direction, the orthographic projection of the second protrusion 2133 overlaps with a portion of the orthographic projection of the current collecting body 241, but does not overlap with the orthographic projection of the pressure relief mechanism 23.

[0158] "The hardness of the second protrusion 2133 is greater than the hardness of the first wall 213" can be: the Rockwell hardness of the second protrusion 2133 is greater than the Rockwell hardness of the first wall 213, or the Brinell hardness of the second protrusion 2133 is greater than the Brinell hardness of the first wall 213, or the Vickers hardness of the second protrusion 2133 is greater than the Vickers hardness of the first wall 213.

[0159] By providing a second protrusion 2133 on the second surface 2132, if the second protrusion 2133 is spaced apart from the current collector 241, when the battery cell 20 is depressurized, even if the current collector 241 deforms towards the first wall 213 under the internal pressure of the battery cell 20, the second protrusion 2133 can still abut against the space between the first surface 2411 and the second surface 2132, so that there is still a gap between the current collector 241 and the first wall 213. This facilitates the flow of the exhaust gas inside the battery cell 20 to the pressure relief mechanism 23, which is beneficial for the smooth depressurization of the battery cell 20 and thus improves the reliability of the battery cell 20. If the second protrusion 2133 abuts against the current collector 241, the second protrusion 2133 can prevent the current collector 241 from deforming towards the first wall 213 to maintain the exhaust gap 214, which is beneficial for the smooth depressurization of the battery cell 20 and thus improves the reliability of the battery cell 20.

[0160] In some embodiments, a plurality of second protrusions 2133 are provided on the first wall 213, and the plurality of second protrusions 2133 are arranged at intervals along the circumferential direction of the pressure relief mechanism 23.

[0161] By arranging multiple second protrusions 2133 at intervals along the circumference of the pressure relief mechanism 23, the multiple second protrusions 2133 can better support the current collector body 241, thereby reducing the deformation range of the current collector body 241, making it less likely for the current collector body 241 to block the pressure relief mechanism 23, which is conducive to the smooth pressure relief of the battery cell 20, thereby improving the reliability of the battery cell 20.

[0162] In some embodiments, the second protrusion 2133 is separately disposed from and connected to the first wall 213.

[0163] "The second protrusion 2133 and the first wall 213 are separately provided and connected" means that during manufacturing, the second protrusion 2133 and the first wall 213 are provided separately, and then the second protrusion 2133 and the first wall 213 are finally connected together. For example, the second protrusion 2133 can be riveted to the first wall 213. Or, the second protrusion 2133 can be welded to the first wall 213.

[0164] When the second protrusion 2133 and the first wall 213 are separately provided and connected, the second protrusion 2133 and the first wall 213 can be made of different materials so that the hardness of the second protrusion 2133 is greater than that of the first protrusion 242. In addition, the second protrusion 2133 and the first wall 213 can be manufactured separately and then connected together, which is more convenient for processing and manufacturing.

[0165] Please refer to Figure 9 and Figure 10 , Figure 10 This is a cross-sectional view of a second protrusion 2133 provided in some embodiments of this application. In some embodiments, the first wall 213 has a third surface 2135 facing away from the electrode assembly 22, and the first wall 213 is provided with a first groove 2136. The first groove 2136 is recessed from the third surface 2135 in a direction pointing from the third surface 2135 to the second surface 2132, and a second protrusion 2133 protruding from the second surface 2132 is formed at a position on the first wall 213 corresponding to the first groove 2136.

[0166] The third surface 2135 is the surface of the first wall 213 facing away from the electrode assembly 22. Along a first direction, the third surface 2135 and the second surface 2132 are disposed opposite to each other. In some embodiments, the second surface 2132 is the inner surface of the first wall 213, and the third surface 2135 is the outer surface of the first wall 213.

[0167] The first groove 2136 is a groove provided on the third surface 2135. During the forming process, the first groove 2136 can be formed on the third surface 2135 by stamping, thereby forming the second protrusion 2133 protruding from the second surface 2132. The forming method of the second protrusion 2133 is simple.

[0168] The use of stamping to form the first groove 2136 will cause the groove wall of the first groove 2136 to undergo cold work hardening (the grain arrangement changes, resulting in lattice distortion, which reduces the plasticity of the metal and increases the hardness of the material), thereby making the hardness of the formed second protrusion 2133 greater than that of the first wall 213.

[0169] Please refer to Figure 10 and Figure 11 , Figure 11 This is a cross-sectional view of a second protrusion 2133 provided for other embodiments of this application. In some embodiments, the surface of the second protrusion 2133 is provided with an anti-corrosion layer 2137 and / or a wear-resistant layer 2138.

[0170] The anti-corrosion layer 2137 is a coating applied to the surface of a workpiece to reduce the risk of electrochemical corrosion. The anti-corrosion layer 2137 can be a coating or an electroplated layer. For example, the anti-corrosion layer 2137 can be a nickel-copper composite plating layer.

[0171] Please refer to Figure 10 The surface of the second protrusion 2133 may only be provided with an anti-corrosion layer 2137. By providing an anti-corrosion layer 2137 on the surface of the second protrusion 2133, it is beneficial to reduce the risk of electrochemical corrosion of the second protrusion 2133 and to maintain the height of the second protrusion 2133 protruding from the second surface 2132, thereby helping to maintain the exhaust gap 214.

[0172] Wear-resistant layer 2138 is a coating layer applied to the surface of a workpiece to reduce the risk of wear. Wear-resistant layer 2138 can be a metal-based composite coating, a metal-based nano-coating, or a metal-based ceramic coating.

[0173] Please refer to Figure 11 Alternatively, the surface of the second protrusion 2133 may only have a wear-resistant layer 2138. Under vibration conditions, the current collector 241 may be subjected to the action of the electrode assembly 22 and come into contact with the second protrusion 2133. By providing a wear-resistant layer 2138 on the surface of the second protrusion 2133, it is beneficial to reduce the risk of the second protrusion 2133 being worn. On the one hand, it is beneficial to maintain the height of the second protrusion 2133 protruding from the second surface 2132, thereby helping to maintain the exhaust gap 214. On the other hand, it is beneficial to reduce the risk of metal debris generated by the wear of the second protrusion 2133 falling into the electrode assembly 22 and causing a short circuit.

[0174] Of course, the surface of the second protrusion 2133 can be provided with both an anti-corrosion layer 2137 and a wear-resistant layer 2138. In some embodiments, the anti-corrosion layer 2137 and the wear-resistant layer 2138 are the same coating. This coating is both resistant to electrochemical corrosion and has good wear resistance. For example, a metal-based nano-coating or a metal-based ceramic coating can be applied to the surface of the second protrusion 2133 to achieve both wear resistance and resistance to electrochemical corrosion. In other embodiments, the anti-corrosion layer 2137 and the wear-resistant layer 2138 are two layered coatings; for example, the wear-resistant layer 2138 can be applied to the outside of the anti-corrosion layer 2137.

[0175] In some embodiments, the first wall 213 is provided with a through hole 2131. A portion of the first protrusion 242 extends out of the through hole 2131 in the direction of the electrode assembly 22 toward the first wall 213, and forms an electrode lead-out portion of the battery cell 20. The first protrusion 242 is insulated from the first wall 213.

[0176] The first wall 213 is provided with a through hole 2131, which penetrates two opposing surfaces of the first wall 213 along a first direction. For example, the first wall 213 includes a second surface 2132 and a third surface 2135 disposed opposite to each other along the first direction, wherein the second surface 2132 faces the electrode assembly 22, and the third surface 2135 faces away from the electrode assembly 22. The through hole 2131 penetrates the second surface 2132 and the third surface 2135 along the first direction.

[0177] "A portion of the first protrusion 242 extends out of the through hole 2131 along the direction of the electrode assembly 22 pointing to the first wall 213", that is, the first protrusion 242 extends beyond the third surface 2135 along the direction of the electrode assembly 22 pointing to the first wall 213.

[0178] The first protrusion 242 serves as the electrode lead-out portion of the battery cell 20. The first protrusion 242 can output electrical energy from the battery cell 20 or input electrical energy into the battery cell 20. That is, the first protrusion 242 serves as the positive or negative output of the battery cell 20.

[0179] The first protrusion 242 is insulated from the first wall 213, that is, the first protrusion 242 is insulated from the first wall 213. Optionally, the battery cell 20 includes an insulating member disposed between the first protrusion 242 and the first wall 213 to insulate the first protrusion 242 from the first wall 213.

[0180] The first protrusion 242 serves as the electrode lead-out portion of the battery cell 20. The first protrusion 242 can output electrical energy from the battery cell 20 or input electrical energy into the battery cell 20. The first protrusion 242 can also serve as a limiting structure to restrict the current collector 24 from moving toward the first wall 213, thereby forming an exhaust gap 214 between the current collector 24 and the first surface 2411 leading to the pressure relief mechanism 23. The first protrusion 242 can also serve as the electrode lead-out portion of the battery cell 20. One structure realizes multiple functions, which helps to simplify the structure of the battery cell 20 and reduce the cost of the battery cell 20.

[0181] Please refer to this again. Figure 5 , Figure 6 , Figure 7 and Figure 8 In some embodiments, the first wall 213 is provided with a through hole 2131, and the first protrusion 242 passes through the through hole 2131 and is welded to the first wall 213.

[0182] The first wall 213 is provided with a through hole 2131, which penetrates two opposing surfaces of the first wall 213 along a first direction. For example, the first wall 213 includes a second surface 2132 and a fourth surface 2139 disposed opposite each other along the first direction, wherein the second surface 2132 faces the electrode assembly 22, and the fourth surface 2139 faces away from the electrode assembly 22. The through hole 2131 penetrates the second surface 2132 and the fourth surface 2139 along the first direction.

[0183] The first protrusion 242 passes through the through hole 2131. In some embodiments, the first protrusion 242 may extend beyond the fourth surface 2139 in the direction of the electrode assembly 22 pointing towards the first wall 213. In other embodiments, the first protrusion 242 does not extend beyond the fourth surface 2139 in the direction of the electrode assembly 22 pointing towards the first wall 213.

[0184] In some embodiments, the third surface 2135 is provided with a second groove, and the fourth surface 2139 is the bottom surface of the second groove. Along the direction from the electrode assembly 22 to the first wall 213, the first protrusion 242 does not extend beyond the third surface 2135.

[0185] The first protrusion 242 is welded to the first wall 213, which can be achieved by welding the outer peripheral surface of the first protrusion 242 to the wall surface of the through hole 2131. Both the current collector 24 and the first wall 213 are conductive components. When the first protrusion 242 is welded to the first wall 213, the first wall 213 serves as the electrode lead-out portion of the battery cell 20. The first wall 213 can output electrical energy from the battery cell 20 or input electrical energy into the battery cell 20, that is, the first wall 213 serves as the positive or negative electrode output of the battery cell 20.

[0186] The first protrusion 242 passes through the through hole 2131. On the one hand, the through hole 2131 can position the first protrusion 242, thereby facilitating welding. On the other hand, the first protrusion 242 and the first wall 213 can be welded from the outside of the outer casing 21, which simplifies the operation and improves the welding quality. When the first protrusion 242 is welded to the first wall 213, the first wall 213 serves as the electrode lead-out part of the battery cell 20, and the first wall 213 can output electrical energy to the battery cell 20 or input electrical energy to the battery cell 20.

[0187] In some embodiments, the current collector 24 is provided with an injection hole 25 for injecting electrolyte into the battery cell 20. One end of the injection hole 25 extends to the end of the first protrusion 242 away from the current collector body 241.

[0188] The current collector 24 is provided with an injection hole 25. One end of the injection hole 25 extends to the end of the first protrusion 242 away from the current collector body 241. That is to say, the first protrusion 242 is provided with an injection hole 25, which allows electrolyte to be injected into the battery cell 20 through the injection hole 25 on the first protrusion 242 without the need to open a hole in the first wall 213. This helps to improve the strength of the first wall 213, reduce the risk of deformation of the first wall 213 under external force, and help maintain the venting gap 214 between the current collector body 241 and the first wall 213, thereby improving the reliability of the battery cell 20.

[0189] In some embodiments, along a first direction, the injection hole 25 penetrates the first protrusion 242 and the collection body 241.

[0190] By allowing the injection hole 25 to pass through the first protrusion 242 and the current collector body 241, the electrolyte injected from the injection hole 25 can flow more quickly to the side of the current collector 24 facing the electrode assembly 22, which helps to improve the injection efficiency.

[0191] In other embodiments, the other end of the injection hole 25 extends to the outer peripheral surface of the first protrusion 242.

[0192] By extending the other end of the injection hole 25 to the outer peripheral surface of the first protrusion 242, the electrolyte injected from the end of the first protrusion 242 away from the current collector 241 can flow into the battery cell 20 from the outer peripheral surface of the first protrusion 242.

[0193] Please refer to Figure 12 , Figure 12This is a top view schematic diagram illustrating the connection between the first wall 213 and the current collecting member 24 in some embodiments of this application. In some embodiments, the first protrusion 242 is welded to the first wall 213 to form a weld mark 243. The pressure relief mechanism 23 is separately disposed from the first wall 213, and the first wall 213 is provided with a pressure relief hole 2134. The pressure relief mechanism 23 is welded to the first wall 213 and covers the pressure relief hole 2134. The minimum distance between the weld mark 243 and the pressure relief mechanism 23 is L, satisfying: 1.5mm ≤ L ≤ 15mm.

[0194] The weld mark 243 is a weld formed by welding the first protrusion 242 and the first wall 213.

[0195] The phrase "the pressure relief mechanism 23 is separately provided from the first wall 213, the first wall 213 is provided with a pressure relief hole 2134, and the pressure relief mechanism 23 is welded to the first wall 213 and covers the pressure relief hole 2134" means that during manufacturing, a pressure relief hole 2134 is provided on the first wall 213, the pressure relief mechanism 23 and the first wall 213 are provided separately, and finally the pressure relief mechanism 23 and the first wall 213 are welded together. For example, the pressure relief mechanism 23 can be an explosion-proof plate welded to the first wall 213.

[0196] L represents the minimum distance between the soldering part 243 and the pressure relief mechanism 23. L can be 1.5mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, etc.

[0197] When L ≥ 1.5 mm, the minimum distance between the solder mark 243 and the pressure relief mechanism 23 is relatively large. When the first protrusion 242 is welded to the first wall 213, the heat from the welding is less likely to affect the weld strength between the pressure relief mechanism 23 and the first wall 213, nor is it likely to affect the burst pressure of the pressure relief mechanism 23, which is beneficial to improving the reliability of the battery cell 20. When L ≤ 15 mm, the minimum distance between the solder mark 243 and the pressure relief mechanism 23 is not too large, which is beneficial to making full use of the space of the battery cell 20 and reducing the risk of interference with other components. Therefore, when 1.5 mm ≤ L ≤ 15 mm, it is possible to improve the reliability of the battery cell 20 and make full use of the space of the battery cell 20, while reducing the risk of interference with other components.

[0198] Optionally, 5mm ≤ L ≤ 10mm.

[0199] L can be 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, etc.

[0200] When L ≥ 5mm, the minimum distance between the solder mark 243 and the pressure relief mechanism 23 is larger. When the first protrusion 242 is welded to the first wall 213, the heat from the welding is less likely to affect the weld strength between the pressure relief mechanism 23 and the first wall 213, and also less likely to affect the burst pressure of the pressure relief mechanism 23, which is beneficial to improving the reliability of the battery cell 20. When L ≤ 10mm, the minimum distance between the solder mark 243 and the pressure relief mechanism 23 is not too large, which is beneficial to making full use of the space of the battery cell 20 and reducing the risk of interference with other components. Therefore, when 5mm ≤ L ≤ 10mm, it is possible to improve the reliability of the battery cell 20 and make full use of the space of the battery cell 20, while reducing the risk of interference with other components.

[0201] In some other embodiments, the pressure relief mechanism 23 is integrally formed with the first wall 213.

[0202] "One-piece molding" means that the first wall 213 and the pressure relief mechanism 23 are provided as a single structure. For example, the pressure relief mechanism 23 can be formed on the first wall 213 by means of stamping or cold forging.

[0203] The pressure relief mechanism 23 is integrally formed with the first wall 213, eliminating the need for additional welding or bonding processes, which helps reduce the risk of leakage from the pressure relief mechanism 23. Furthermore, during production, it is easier to ensure that the detonation pressure of multiple battery cells 20 produced is more consistent.

[0204] Please refer to this again. Figure 5 , Figure 6 and Figure 7 In some embodiments, the first protrusion 242 and the current collection body 241 are integrally formed.

[0205] "The first protrusion 242 and the current collecting body 241 are integrally formed" means that the first protrusion 242 and the current collecting body 241 are provided as a single structure. For example, the current collecting member 24 can be manufactured by casting, in which case the first protrusion 242 and the current collecting body 241 are a single structure. Alternatively, the first protrusion 242 can be stamped onto the current collecting body 241 by stamping.

[0206] When the first protrusion 242 and the current collector body 241 are integrally formed, the integrity of the first protrusion 242 and the current collector body 241 is better, the connection strength of the first protrusion 242 and the current collector body 241 is higher, and the connection position of the first protrusion 242 and the current collector body 241 is not easily deformed or damaged. This is conducive to maintaining the exhaust gap 214 between the current collector body 241 and the first wall 213, thereby facilitating the smooth pressure release of the battery cell 20 and improving the reliability of the battery cell 20.

[0207] This application embodiment also provides a battery device 100, which includes the aforementioned battery cell 20.

[0208] 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.

[0209] According to some embodiments of this application, please refer to Figures 3 to 12 .

[0210] This application provides a battery cell 20, which includes a housing 21, an electrode assembly 22, a pressure relief mechanism 23, and a current collector 24. The housing 21 has a first wall 213, and the electrode assembly 22 is housed within the housing 21. The electrode assembly 22 includes a main body 231 and a first tab 232, with the first tab 232 disposed at the end of the main body 231 facing the first wall 213 along a first direction. The pressure relief mechanism 23 is disposed on the first wall 213. The current collector 24 includes a current collector body 241 and a first protrusion 242. Along the first direction, at least a portion of the current collector body 241 is disposed between the first wall 213 and the first tab 232, and the current collector body 241 is connected to the first tab 232. The current collector body 241 has a first surface 2411 facing the first wall 213, and the first protrusion 242 is disposed on the first surface 2411. The first protrusion 242 abuts against the first wall 213, forming an exhaust gap 214 between the first surface 2411 and the first wall 213, leading to the pressure relief mechanism 23. The hardness of the current collector body 241 is greater than that of the first wall 213. The current collector 24 of the battery cell 20 is provided with the first protrusion 242, which can directly or indirectly abut against the first wall 213, thereby forming an exhaust gap 214 between the current collector body 241 and the first wall 213, leading to the pressure relief mechanism 23. By making the hardness of the current collector body 241 greater than that of the first wall 213, the current collector body 241 also has higher strength. Thus, the current collector body 241 is less likely to deform under the internal air pressure of the battery cell 20, thereby maintaining the exhaust gap 214 and reducing the risk of the current collector body 241 blocking the pressure relief mechanism 23. When the battery cell 20 is depressurized, the emissions from the battery cell 20 can flow to the depressurization mechanism 23 through the exhaust gap 214, which facilitates the smooth depressurization of the battery cell 20 and helps to improve the reliability of the battery cell 20.

[0211] The Vickers hardness of the current collector 241 is A1, and the Vickers hardness of the first wall 213 is A2, satisfying 1.2 ≤ A1 / A2 ≤ 1.8. When A1 / A2 ≥ 1.2, the Vickers hardness of the current collector 241 is relatively high, and the current collector 241 also has relatively high strength, making it less prone to deformation under the internal air pressure of the battery cell 20. This helps maintain the exhaust gap 214, reduces the risk of the current collector 241 blocking the pressure relief mechanism 23, and improves the reliability of the battery cell 20. When A1 / A2 ≤ 1.8, the Vickers hardness of the current collector 241 is not too high, which facilitates processing and manufacturing, and helps reduce the manufacturing cost of the battery cell 20. Therefore, when 1.2 ≤ A1 / A2 ≤ 1.8, both the reliability of the battery cell 20 can be improved, and the manufacturing cost is lower.

[0212] 1.3 ≤ A1 / A2 ≤ 1.6. When A1 / A2 ≥ 1.3, the Vickers hardness of the current collector 241 is greater, and the current collector 241 also has higher strength. This makes the current collector 241 less prone to deformation under the internal air pressure of the battery cell 20, thus better maintaining the exhaust gap 214 and further reducing the risk of the current collector 241 blocking the pressure relief mechanism 23, which is beneficial to improving the reliability of the battery cell 20. When A1 / A2 ≤ 1.6, the Vickers hardness of the current collector 241 is not too high, which facilitates processing and manufacturing, and helps to reduce the manufacturing cost of the battery cell 20. Therefore, when 1.3 ≤ A1 / A2 ≤ 1.6, both the reliability of the battery cell 20 can be improved and the manufacturing cost is lower.

[0213] The Vickers hardness of the current collector 241 is A1, satisfying: 110HV ≤ A1 ≤ 150HV. When A1 ≥ 110HV, the Vickers hardness of the current collector 241 is relatively high, and the current collector 241 also has correspondingly high strength. This makes the current collector 241 less prone to deformation under the internal air pressure of the battery cell 20, thus helping to maintain the exhaust gap 214, reducing the risk of the current collector 241 blocking the pressure relief mechanism 23, and improving the reliability of the battery cell 20. When A1 ≤ 150HV, the Vickers hardness of the current collector 241 is not too high, thus facilitating processing and manufacturing, and helping to reduce the manufacturing cost of the battery cell 20. Therefore, when 110HV ≤ A1 ≤ 150HV, both the reliability of the battery cell 20 can be improved, and the manufacturing cost is lower.

[0214] 120HV≤A1≤140HV. When A1≥120HV, the Vickers hardness of the current collector 241 is greater, and the current collector 241 also has higher strength. This makes the current collector 241 less prone to deformation under the internal air pressure of the battery cell 20, thus better maintaining the exhaust gap 214 and further reducing the risk of the current collector 241 blocking the pressure relief mechanism 23, which is beneficial to improving the reliability of the battery cell 20. When A1≤140HV, the Vickers hardness of the current collector 241 is not too high, which facilitates processing and manufacturing, and helps to reduce the manufacturing cost of the battery cell 20. Therefore, when 120HV≤A1≤140HV, both the reliability of the battery cell 20 can be improved and the manufacturing cost can be lower.

[0215] Along a first direction, the first wall 213 has a second surface 2132 facing the electrode assembly 22, and an exhaust gap 214 is formed between the second surface 2132 and the first surface 2411. A second protrusion 2133 is provided on the second surface 2132, and the second protrusion 2133 is disposed opposite to the current collecting body 241. The hardness of the second protrusion 2133 is greater than the hardness of the first wall 213. By providing a second protrusion 2133 on the second surface 2132, if the second protrusion 2133 is spaced apart from the current collector 241, when the battery cell 20 is depressurized, even if the current collector 241 deforms towards the first wall 213 under the internal pressure of the battery cell 20, the second protrusion 2133 can still abut against the space between the first surface 2411 and the second surface 2132, so that there is still a gap between the current collector 241 and the first wall 213. This facilitates the flow of the exhaust gas inside the battery cell 20 to the pressure relief mechanism 23, which is beneficial for the smooth depressurization of the battery cell 20 and thus improves the reliability of the battery cell 20. If the second protrusion 2133 abuts against the current collector 241, the second protrusion 2133 can prevent the current collector 241 from deforming towards the first wall 213 to maintain the exhaust gap 214, which is beneficial for the smooth depressurization of the battery cell 20 and thus improves the reliability of the battery cell 20.

[0216] The surface of the second protrusion 2133 is provided with an anti-corrosion layer 2137 and / or a wear-resistant layer 2138. By providing the anti-corrosion layer 2137 on the surface of the second protrusion 2133, the risk of electrochemical corrosion of the second protrusion 2133 is reduced, and the height of the second protrusion 2133 protruding from the second surface 2132 is maintained, thereby maintaining the exhaust gap 214. Under vibration conditions, the current collector 241 may be subjected to the action of the electrode assembly 22 and come into contact with the second protrusion 2133. By providing the wear-resistant layer 2138 on the surface of the second protrusion 2133, the risk of wear on the second protrusion 2133 is reduced. On the one hand, this helps maintain the height of the second protrusion 2133 protruding from the second surface 2132, thereby maintaining the exhaust gap 214; on the other hand, it reduces the risk of metal debris generated by wear on the second protrusion 2133 falling into the electrode assembly 22 and causing a short circuit.

[0217] The first wall 213 is provided with a through hole 2131. A portion of the first protrusion 242 extends out of the through hole 2131 along the direction of the electrode assembly 22 pointing towards the first wall 213, forming the electrode lead-out portion of the battery cell 20. The first protrusion 242 is insulated from the first wall 213. As the electrode lead-out portion of the battery cell 20, the first protrusion 242 can output or input electrical energy to the battery cell 20. The first protrusion 242 can also serve as a limiting structure, restricting the current collector 24 from moving towards the first wall 213, thereby forming an exhaust gap 214 between the current collector 24 and the first surface 2411 leading to the pressure relief mechanism 23. The first protrusion 242 can also serve as the electrode lead-out portion of the battery cell 20. One structure realizes multiple functions, which helps to simplify the structure of the battery cell 20 and reduce the cost of the battery cell 20.

[0218] 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: The outer shell has a first wall; An electrode assembly is housed within the housing. The electrode assembly includes a main body and a first electrode tab, wherein the first electrode tab is disposed at one end of the main body facing the first wall along a first direction. A pressure relief mechanism is installed on the first wall; A flow collector includes a flow collector body and a first protrusion. Along the first direction, at least a portion of the flow collector body is disposed between the first wall and the first electrode tab. The flow collector body is connected to the first electrode tab. The flow collector body has a first surface facing the first wall. The first protrusion is disposed on the first surface and abuts against the first wall, thereby forming an exhaust gap between the first surface and the first wall leading to the pressure relief mechanism. The hardness of the flow collector body is greater than the hardness of the first wall.

2. The battery cell according to claim 1, characterized in that, The Vickers hardness of the current collector body is A1, and the Vickers hardness of the first wall is A2, satisfying: 1.2≤A1 / A2≤1.

8.

3. The battery cell according to claim 2, characterized in that, 1.3≤A1 / A2≤1.

6.

4. The battery cell according to claim 1, characterized in that, The Vickers hardness of the current collector is A1, which satisfies: 110HV≤A1≤150HV.

5. The battery cell according to claim 4, characterized in that, 120HV≤A1≤140HV.

6. The battery cell according to claim 1, characterized in that, Along the first direction, the first wall has a second surface facing the electrode assembly, and the exhaust gap is formed between the second surface and the first surface. A second protrusion is provided on the second surface, and the second protrusion is disposed opposite to the current collecting body. The hardness of the second protrusion is greater than the hardness of the first wall.

7. The battery cell according to claim 6, characterized in that, The second protrusion is separately disposed from and connected to the first wall.

8. The battery cell according to claim 6, characterized in that, The first wall has a third surface facing away from the electrode assembly. The first wall is provided with a first groove, which is recessed from the third surface in a direction pointing from the third surface to the second surface. A second protrusion is formed on the first wall at a position corresponding to the first groove, protruding from the second surface.

9. The battery cell according to claim 6, characterized in that, The surface of the second protrusion is provided with an anti-corrosion layer and / or a wear-resistant layer.

10. The battery cell according to any one of claims 1-9, characterized in that, The first wall is provided with a through hole, and a portion of the first protrusion extends out of the through hole in the direction of the electrode assembly pointing towards the first wall, forming the electrode lead-out portion of the battery cell. The first protrusion is insulated from and connected to the first wall.

11. The battery cell according to any one of claims 1-9, characterized in that, The first wall is provided with a through hole, and the first protrusion passes through the through hole and is welded to the first wall.

12. The battery cell according to claim 11, characterized in that, The first protrusion is welded to the first wall to form a weld mark. The pressure relief mechanism is separately disposed from the first wall. The first wall is provided with a pressure relief hole. The pressure relief mechanism is welded to the first wall and covers the pressure relief hole. The minimum distance between the soldering part and the pressure relief mechanism is L, which satisfies: 1.5mm≤L≤15mm.

13. The battery cell according to any one of claims 1-9, characterized in that, The first protrusion and the current collection body are integrally formed.

14. A battery device, characterized in that, Includes the battery cell according to any one of claims 1-13.

15. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1-13, the battery cell being used to provide electrical energy to the electrical device.

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