Battery cell, battery device, power consuming device, and energy storage device

Abstract

Embodiments of the present application provide a battery monomer, a battery device, a power consumption device and an energy storage device, which can improve the use performance of the battery monomer. The battery monomer comprises a shell, an electrode assembly and a pressure relief mechanism, the shell has a first wall, the first wall is provided with a pressure relief hole penetrating along the thickness direction of the first wall, the electrode assembly is contained in the shell, the pressure relief mechanism covers the pressure relief hole, the pressure relief mechanism comprises a pressure relief part and a connecting part, the connecting part is located outside the pressure relief part, at least part of the connecting part is connected to the first wall, one side of the pressure relief part close to the connecting part is provided with a weak part, the weak part is configured to be damaged to release pressure when the temperature or pressure inside the shell reaches a threshold value, the pressure relief mechanism further comprises at least one bending part arranged between the connecting part and the weak part, the bending part is bent relative to the connecting part, and the material of the pressure relief mechanism is steel or titanium alloy.

Description

Technical Field

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

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] In the development of battery technology, besides improving the electrical performance of battery devices, safety is also a crucial issue. If the safety of individual battery cells cannot be guaranteed, they become unusable, reducing their performance. Therefore, improving the performance of individual battery cells has become a pressing technical problem to be solved in this field. Utility Model Content

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

[0005] In a first aspect, a battery cell is provided, comprising: a housing having a first wall having a pressure relief hole extending through the thickness of the first wall; an electrode assembly housed within the housing; and a pressure relief mechanism covering the pressure relief hole, the pressure relief mechanism including a pressure relief portion and a connecting portion, the connecting portion being located outside the pressure relief portion and at least partially connected to the first wall, the pressure relief portion having a weak portion on the side near the connecting portion, the weak portion being configured to be destroyed to release the pressure when the temperature or pressure inside the housing reaches a threshold; wherein the pressure relief mechanism further includes at least one bending portion disposed between the connecting portion and the weak portion, the bending portion being bent relative to the connecting portion, and the pressure relief mechanism being made of steel or titanium alloy.

[0006] In this embodiment, the pressure relief mechanism of the battery cell is configured to include a pressure relief portion and a connecting portion. The connecting portion is located outside the pressure relief portion and is at least partially connected to the first wall. A weak portion is provided on the side of the pressure relief portion near the connecting portion. The weak portion is configured to be broken to release the pressure when the temperature or pressure inside the housing reaches a threshold. The pressure relief mechanism also includes at least one bending portion disposed between the connecting portion and the weak portion. The bending portion is bent relative to the connecting portion. Thus, during the welding process of the pressure relief mechanism to the first wall, since the material of the pressure relief mechanism is steel or titanium alloy, the pressure relief mechanism is not easily deformed. Stress concentration is easily generated in the weak portion of the pressure relief mechanism. The bending portion can absorb the radial thermal stress generated during the welding process, reducing the risk of a decrease in the actuation performance of the pressure relief mechanism due to cracking in the weak portion, thereby improving the performance of the pressure relief mechanism and thus improving the performance of the battery cell.

[0007] In some embodiments, along the thickness direction of the pressure relief mechanism, there is a height difference between the side of the bend near the first wall and the side of the bend near the weak portion.

[0008] In this embodiment, along the thickness direction of the pressure relief mechanism, a height difference is set between the side of the bend near the first wall and the side of the bend near the weak part. During the welding process of the pressure relief mechanism to the first wall, the radial thermal stress generated during the welding process is effectively absorbed by the bend, reducing the risk of a decrease in the actuation performance of the pressure relief mechanism due to cracking at the weak part, thereby improving the performance of the pressure relief mechanism and thus improving the performance of the battery cell.

[0009] In some embodiments, the bent portion is inclined relative to the thickness direction of the pressure relief mechanism.

[0010] In this embodiment, by tilting the bent portion relative to the thickness direction of the pressure relief mechanism, the radial thermal stress generated during the welding process of the pressure relief mechanism to the first wall is effectively absorbed by the bent portion, while the maximum size of the pressure relief mechanism along the thickness direction of the pressure relief mechanism is reduced, thereby improving the space utilization rate inside the battery cell casing, facilitating the processing and manufacturing of the pressure relief mechanism, and thus improving the performance of the battery cell.

[0011] In some embodiments, at least one of the bends includes an adjacent first bend and a second bend, the first bend and the second bend forming a protrusion protruding toward or away from the electrode assembly, the protrusion being disposed around the pressure relief portion.

[0012] In this embodiment, by configuring at least one of the bending portions as including an adjacent first bending portion and a second bending portion, and the first bending portion and the second bending portion forming a protrusion protruding in a direction toward or away from the electrode assembly, the radial thermal stress generated during the welding process of the pressure relief mechanism to the first wall can be absorbed by the protrusion, reducing the risk of a decrease in the actuation performance of the pressure relief mechanism due to cracking in the weak part, thereby improving the performance of the pressure relief mechanism and thus improving the performance of the battery cell.

[0013] In some embodiments, the protrusion protrudes in a direction away from the electrode assembly. Thus, in this embodiment, by setting the protrusion to protrude in a direction away from the electrode assembly, the impact of the protrusion on the interior of the battery cell's casing is reduced, improving the space utilization within the battery cell's casing. During the welding of the pressure relief mechanism to the first wall, the protrusion can absorb the radial thermal stress generated during welding, reducing the risk of decreased actuation performance of the pressure relief mechanism due to cracking at weak points, thereby improving the performance of the pressure relief mechanism and ultimately improving the performance of the battery cell.

[0014] In some embodiments, in the thickness direction of the first wall, the dimension D1 of the protrusion satisfies: 0.05mm≤D1≤0.5mm.

[0015] In this embodiment of the application, in the thickness direction of the first wall, by setting the size D1 of the protrusion to satisfy: 0.05mm≤D1≤0.5mm, during the process of welding the pressure relief mechanism to the first wall, the radial thermal stress generated during the welding process by the protrusion is taken into account, and the performance of the pressure relief mechanism is improved. This reduces the risk of the pressure relief mechanism's actuation performance being reduced due to cracking in the weak part, thereby improving the performance of the battery cell.

[0016] In some embodiments, the side of the protrusion facing the electrode assembly has a groove structure with an opening facing the electrode assembly.

[0017] In this embodiment, by forming a groove structure with an opening facing the electrode assembly on the side of the protrusion facing the electrode assembly, the radial thermal stress generated during the welding process can be effectively absorbed by the protrusion containing the groove structure during the welding process of the pressure relief mechanism to the first wall. This reduces the risk of the pressure relief mechanism's actuation performance deteriorating due to cracking in the weak part, thereby improving the performance of the pressure relief mechanism and thus improving the performance of the battery cell.

[0018] In some embodiments, the dimension D2 of the groove structure in the thickness direction perpendicular to the first wall satisfies: 0.1mm≤D2≤2mm.

[0019] In this embodiment, in the direction perpendicular to the thickness of the first wall, by setting the dimension D2 of the groove structure to satisfy: 0.1mm≤D2≤2mm, during the welding of the pressure relief mechanism to the first wall, the radial thermal stress generated during the welding process is absorbed by the protrusion containing the groove structure, and the performance of the pressure relief mechanism is balanced. This reduces the risk of a decrease in the actuation performance of the pressure relief mechanism due to cracking in the weak part, and at the same time facilitates the processing and manufacturing of the pressure relief mechanism, thereby improving the performance of the battery cell.

[0020] In some embodiments, in the thickness direction perpendicular to the first wall, the dimension D3 between the inner wall of the groove structure on the side away from the pressure relief portion and the surface of the protrusion on the side away from the pressure relief portion satisfies: 0.05mm≤D3≤1mm.

[0021] In this embodiment, in the thickness direction perpendicular to the first wall, by setting the dimension D3 between the inner wall of the groove structure away from the pressure relief part and the surface of the protrusion away from the pressure relief part to satisfy: 0.05mm≤D3≤1mm, during the welding process of the pressure relief mechanism to the first wall, the protrusion can effectively absorb the radial thermal stress generated during the welding process, reduce the risk of the pressure relief mechanism's actuation performance deteriorating due to cracking in the weak part, and improve the performance of the battery cell.

[0022] In some embodiments, in the thickness direction perpendicular to the first wall, the dimension D4 between the inner wall of the groove structure away from the pressure relief portion and the surface of the connection portion near the pressure relief hole satisfies: 0.3mm≤D4≤10mm.

[0023] In this embodiment, in the thickness direction perpendicular to the first wall, by setting the dimension D4 between the inner wall of the groove structure away from the pressure relief part and the surface of the connecting part near the pressure relief hole to satisfy: 0.3mm≤D4≤10mm, during the welding process of the pressure relief mechanism to the first wall, both the connection strength between the first wall and the pressure relief mechanism and the ability of the protrusion to absorb the radial thermal stress generated during the welding process are taken into account. This reduces the risk of the pressure relief mechanism's actuation performance deteriorating due to cracking in the weak part, thereby improving the performance of the battery cell.

[0024] In some embodiments, the inner wall of the groove structure on the side away from the pressure relief hole is the portion of the pressure relief part closest to the pressure relief hole.

[0025] In this embodiment of the application, by making the inner wall of the groove structure away from the pressure relief hole the part of the pressure relief part close to the pressure relief hole, during the process of welding the pressure relief mechanism to the first wall, the ability of the protrusion to absorb the radial thermal stress generated during the welding process and the manufacturing performance of the pressure relief mechanism are taken into account. This reduces the risk of the pressure relief mechanism's actuation performance being reduced due to cracking in the weak part, thereby improving the performance of the battery cell.

[0026] In some embodiments, the pressure relief hole includes a first hole and a second hole distributed in a stepped manner. One end of the first hole is formed on the surface of the first wall facing the electrode assembly. The second hole is located on the side of the first hole away from the electrode assembly. The diameter of the first hole is smaller than the diameter of the second hole. The side of the connection portion away from the pressure relief portion is welded to the inner wall of the second hole.

[0027] In this embodiment, the pressure relief hole is configured to include a first hole and a second hole distributed in a stepped manner. One end of the first hole is formed on the surface of the first wall facing the electrode assembly, and the second hole is located on the side of the first hole away from the electrode assembly. The diameter of the first hole is smaller than that of the second hole. The side of the connecting part away from the pressure relief part is welded to the inner wall of the second hole. This is to balance the connection strength and assembly performance between the pressure relief mechanism and the first wall, thereby improving the performance of the battery cell.

[0028] In some embodiments, a first surface away from the electrode assembly is formed between the first hole and the second hole, and at least a portion of the surface of the connection portion facing the electrode assembly abuts against the first surface.

[0029] In this embodiment, a first surface away from the electrode assembly is formed between the first hole and the second hole. By setting at least a portion of the surface of the connection portion facing the electrode assembly to abut against the first surface, the connection strength between the pressure relief mechanism and the first wall and the performance of the pressure relief mechanism are taken into account, thereby improving the performance of the battery cell.

[0030] In a second aspect, a battery device is provided, comprising: a plurality of battery cells, wherein the battery cells are those described in the first aspect or its various implementations.

[0031] Thirdly, an electrical device is provided, including the battery device described in the second aspect, the battery device being used to provide electrical energy to the electrical device.

[0032] In some implementations, the electrical device can be a vehicle, ship, or spacecraft.

[0033] Fourthly, an energy storage device is provided, including the battery device described in the second aspect, the battery device being used to store electrical energy for the energy storage device. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of a vehicle provided in one embodiment of this application.

[0036] Figure 2 This is a schematic diagram of the structure of a battery device provided in an embodiment of this application.

[0037] Figure 3 This is a schematic diagram of the structure of a battery cell provided in an embodiment of this application.

[0038] Figure 4 This is a schematic diagram of the structure of a battery cell provided in another embodiment of this application.

[0039] Figure 5 This is an exploded structural diagram of a battery cell provided in an embodiment of this application.

[0040] Figure 6 This is a cross-sectional schematic diagram of a battery cell provided in an embodiment of this application.

[0041] Figure 7 This is a partially enlarged cross-sectional schematic diagram of a battery cell provided in an embodiment of this application.

[0042] Figure 8 This is a partially enlarged cross-sectional schematic diagram of a battery cell provided in another embodiment of this application.

[0043] Figure 9 This is a partially enlarged cross-sectional schematic diagram of a battery cell provided in another embodiment of this application.

[0044] Figure 10 This is a partially enlarged cross-sectional schematic diagram of a battery cell provided in another embodiment of this application.

[0045] Figure 11 This is a partially enlarged cross-sectional schematic diagram of a battery cell provided in another embodiment of this application.

[0046] Figure 12 This is a partially enlarged cross-sectional schematic diagram of a battery cell provided in another embodiment of this application.

[0047] Figure 13 This is a partially enlarged cross-sectional schematic diagram of a battery cell provided in another embodiment of this application.

[0048] Figure 14 This is a partially enlarged cross-sectional schematic diagram of a battery cell provided in another embodiment of this application.

[0049] Figure 15 This is a partially enlarged cross-sectional schematic diagram of a battery cell provided in another embodiment of this application.

[0050] Figure 16 This is a partially enlarged cross-sectional schematic diagram of a battery cell provided in another embodiment of this application.

[0051] Explanation of reference numerals in the attached drawings: 1-Vehicle; 10-Battery unit; 20-Battery cell; 30-Controller; 40-Motor; 11-Casing; 111-First part; 112-Second part; 112a-Base plate; 112b-Side plate; 21-Outer shell; 22-Electrode assembly; 211-Housing shell; 212-End cap assembly; 222-Electrode tab; 222a-Positive electrode tab; 222b-Negative electrode tab; 213-Pressure relief mechanism; 2131-Pressure relief section; 2132-Connection section; 2133-Weak section; 214-Electrode Terminal; 214a-First electrode terminal; 214b-Second electrode terminal; 23-Connecting member; 50-Receiving cavity; 215-First wall; 2151-First surface; 216-Injection hole; 217-Bottom plate; 218-Insulating component; 219-Adhesive component; 60-Protective component; 70-Pressure relief hole; 710-First hole; 720-Second hole; 730-Third hole; 80-Soldering part; 90-Bending part; 901-First bending part; 902-Second bending part; 910-Protrusion; 911-Groove structure.

[0052] The accompanying drawings are not drawn to scale. Detailed Implementation

[0053] 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.

[0054] 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.

[0055] In this application, the reference to "embodiment" means that a specific 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 throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0060] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0061] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0062] 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.

[0063] 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.

[0064] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0065] 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 for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate 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 manganese iron phosphate, and lithium manganese iron phosphate and carbon composites. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also abbreviated as NCM333), LiNi0.5Co0.2Mn0.3O2 (also abbreviated as NCM523), LiNi0.5Co The following are included: 0.25Mn0.25O2 (also known as NCM211), LiNi0.6Co0.2Mn0.2O2 (also known as NCM622), LiNi0.8Co0.1Mn0.1O2 (also known as NCM811), lithium nickel cobalt aluminum oxides (such as LiNi0.8Co0.15Al0.05O2), and their modified compounds. Modified compounds refer to substances obtained by doping or coating, etc., based on the above-mentioned materials.

[0066] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, 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, a positive electrode active material is filled and / or deposited within the foamed metal.

[0067] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0068] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0069] 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.

[0070] 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.

[0071] 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 for battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0072] In some embodiments, the negative electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0073] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0074] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0075] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0076] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0077] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0078] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0079] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0080] Liquid electrolytes include electrolyte salts and solvents.

[0081] In some embodiments, the electrolyte salt may be selected from 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.

[0082] In some embodiments, the solvent may be selected from at least one of 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 of 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.

[0083] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of the battery cell, such as additives that improve the overcharge / fast charge performance of the battery cell, additives that improve the high-temperature performance of the battery cell, and additives that improve the low-temperature performance of the battery cell.

[0084] The gel electrolyte includes a polymer as a backbone network and can be used in conjunction with an ionic liquid-lithium salt.

[0085] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0086] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0087] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0088] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0089] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0090] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0091] In some implementations, the electrode assembly is a stacked structure.

[0092] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0093] 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.

[0094] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0095] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0096] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0097] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0098] In some embodiments, the electrode assembly has tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0099] In some embodiments, the battery cell may include a casing. The casing may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. In some embodiments, the casing may be a sealed structure or a non-sealed structure. As an example, when the casing is a non-sealed structure, the casing serves to protect the electrode assembly, and a sealing bag is included between the casing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag may be a bag-shaped insulating component or an aluminum-plastic film. When the casing is a sealed structure, it is used to encapsulate components such as the electrode assembly and electrolyte.

[0100] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0101] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab. The electrode terminal can be directly connected to the tab, or it can be indirectly connected to the tab through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0102] In some embodiments, a pressure relief mechanism is provided on the casing. The pressure relief mechanism is used to release the internal gas of the battery cell.

[0103] As an example, the internal pressure or temperature of a battery cell is actuated to release the internal pressure or temperature when it reaches a predetermined threshold. When the internal pressure or temperature of the battery cell reaches the predetermined threshold, the pressure relief mechanism is activated or a weak structure in the pressure relief mechanism is broken, thereby creating an opening or channel for the internal pressure or temperature to be released. The threshold design varies depending on the design requirements. The threshold may depend on the materials of one or more of the positive electrode, negative electrode, electrolyte, and separator in the battery cell.

[0104] As an example, the pressure relief mechanism can be integrally molded with the housing.

[0105] As an example, the pressure relief mechanism can also be separately installed and connected to the housing.

[0106] The term "actuation" as used in this application refers to the activation or actuation of the pressure relief mechanism to a certain state, thereby releasing the internal pressure and temperature of the battery cell. The actions of the pressure relief mechanism may include, but are not limited to: movement of components within the mechanism to form an exhaust channel, rupture, breakage, tearing, or opening of at least a portion of the mechanism, etc. When the pressure relief mechanism is activated, the high-temperature, high-pressure substances inside the battery cell are discharged as waste from the activated portion. This method allows for pressure and temperature relief of the battery cell under controllable pressure or temperature, thereby preventing potentially more serious accidents.

[0107] In some embodiments, when the housing is a non-sealed structure, the pressure relief mechanism can be configured as a through hole for venting gas inside the battery cell.

[0108] The emissions from battery cells mentioned in this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of separators, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0109] 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.

[0110] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0111] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0112] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0113] 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.

[0114] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0115] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0116] 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.

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

[0118] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use individual battery cells, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0119] This application provides an energy storage device including one or more battery clusters to increase the voltage and capacity of the energy storage device. The battery clusters may include multiple battery devices, which are connected in series via a busbar to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, the multiple battery clusters are connected in parallel to increase the capacity of the energy storage device.

[0120] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, an energy storage device can store electrical energy during off-peak hours and provide power to relevant users or electrical devices during peak hours. The energy storage system provided in this application embodiment can be any power system that requires energy storage devices.

[0121] In some embodiments, the energy storage device is an energy storage container or an energy storage cabinet.

[0122] In some embodiments, the energy storage device may include a cabinet and one or more battery clusters housed within the cabinet.

[0123] In some embodiments, the energy storage device may include modules such as a thermal management module, a main control module, a central control module, a power distribution module, and a fire protection module.

[0124] As an example, the thermal management module may include a liquid cooling unit that supplies coolant to each battery device via piping to regulate the temperature of the individual battery cells.

[0125] As an example, the main control module can serve as the battery management unit for the battery cluster, used to monitor and manage the battery cluster. The main control module can monitor information such as the current, voltage, power, or temperature of the battery cluster. For instance, it can control the charging and discharging current and voltage of the battery cluster. The main control module includes auxiliary battery management units, integrated switches, and other modules.

[0126] As an example, the central control module can serve as the battery management unit for an energy storage device, used to monitor and manage the device. The central control module can monitor information such as the energy storage device's current, voltage, power, state of charge, or temperature. For instance, it can control the charging and discharging current and voltage of the energy storage device. As an example, the central control module includes modules such as an insulation monitoring module, a main battery management unit, and Ethernet and fiber optic conversion modules.

[0127] As an example, a fire protection system includes control panels, detectors, alarm devices, etc., used to detect, alarm, or extinguish fires in energy storage systems.

[0128] As an example, the power distribution unit can be used to distribute power to the power modules of the energy storage device.

[0129] Currently, energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development. In the development of battery technology, besides improving the electrical performance of battery devices, safety is also a critical issue. During the assembly of battery cells, a thin groove is typically made on the surface of the pressure relief mechanism's cavity, away from the battery cell. During the welding of the pressure relief mechanism to the housing, the thermal stress generated in the welding area is easily conducted to the groove, causing the pressure relief mechanism to crack at that location. This reduces the performance of the pressure relief mechanism and, consequently, the performance of the battery cell. If the safety of the battery cell cannot be guaranteed, the battery cell becomes unusable, further reducing its performance. Therefore, improving the performance of battery cells has become a pressing technical problem in this field.

[0130] Therefore, embodiments of this application provide a battery cell, a battery device, an electrical device, and an energy storage device. The battery cell includes a housing, an electrode assembly, and a pressure relief mechanism. The housing has a first wall with a pressure relief hole extending through the thickness of the first wall. The electrode assembly is housed within the housing. The pressure relief mechanism covers the pressure relief hole and includes a pressure relief portion and a connecting portion. The connecting portion is located outside the pressure relief portion and is at least partially connected to the first wall. A weak portion is provided on the side of the pressure relief portion near the connecting portion. The weak portion is configured to be destroyed to release the pressure when the temperature or pressure inside the housing reaches a threshold. The pressure relief mechanism also includes at least one bending portion disposed between the connecting portion and the weak portion, the bending portion being bent relative to the connecting portion. The material of the pressure relief mechanism is steel or titanium alloy. Thus, in this embodiment, by configuring the pressure relief mechanism of the battery cell to include a pressure relief portion and a connecting portion, the connecting portion being located outside the pressure relief portion and at least partially connected to the first wall, and a weak portion being provided on the side of the pressure relief portion near the connecting portion, the weak portion being configured to be destroyed to release the pressure when the temperature or pressure inside the housing reaches a threshold, the pressure relief mechanism also includes at least one bending portion disposed between the connecting portion and the weak portion, the bending portion being bent relative to the connecting portion, so that during the welding process of the pressure relief mechanism to the first wall, since the material of the pressure relief mechanism is set to steel or titanium alloy, the pressure relief mechanism is not easily deformed, and stress concentration is easily generated in the weak portion of the pressure relief mechanism. The radial thermal stress generated during the welding process can be absorbed through the bending portion, reducing the risk of a decrease in the actuation performance of the pressure relief mechanism due to cracking in the weak portion, thereby improving the performance of the pressure relief mechanism and thus improving the performance of the battery cell.

[0131] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery devices.

[0132] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0133] It should be understood that the technical solutions described in the embodiments of this application are not limited to the electrical devices described above, but can also be applied to all devices that use batteries. For the sake of simplicity, the following embodiments will be described in detail using a vehicle as an example of an electrical device.

[0134] For example, such as Figure 1 The diagram shown is a structural schematic of a vehicle 1 according to one embodiment of this application. Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A motor 40, a controller 30, and a battery device 10 can be installed inside vehicle 1. The controller 30 controls the battery device 10 to supply power to the motor 40. For example, the battery device 10 can be installed at the bottom, front, or rear of vehicle 1. The battery device 10 can be used to power vehicle 1. For example, the battery device 10 can serve as the operating power source for vehicle 1, for example, to meet the electrical system requirements of vehicle 1, such as for starting, navigation, and operation. In another embodiment of this application, the battery device 10 can not only serve as the operating power source for vehicle 1, but also as the driving power source for vehicle 1, replacing or partially replacing gasoline or natural gas to provide driving power for vehicle 1.

[0135] To meet different power demands, the battery device 10 in this embodiment may include at least one battery cell assembly, which comprises multiple battery cells. These multiple battery cells can be electrically connected in series, parallel, or a combination thereof to form the battery device 10. A combination of series and parallel connections is used. The battery device 10 may also be referred to as a battery pack. For example, multiple battery cells can first be connected in series, parallel, or a combination to form a battery module, and then multiple battery modules can be connected in series, parallel, or a combination thereof to form the battery device 10. That is, multiple battery cells can directly form the battery device 10, or they can first be assembled into battery modules, and then the battery modules can be assembled into the battery device 10.

[0136] For example, such as Figure 2 The diagram shown is a structural schematic of a battery device 10 according to an embodiment of this application. The battery device 10 may include a plurality of battery cells 20. The battery device 10 may also include a housing 11 (or cover), the housing 11 having a hollow structure, and the plurality of battery cells 20 are housed within the housing 11. For example, the plurality of battery cells 20 may be connected in parallel, in series, or in a mixed configuration and then placed within the housing 11.

[0137] like Figure 2As shown, the housing 11 may include two parts, referred to here as the first part 111 and the second part 112, which are fastened together. The shapes of the first part 111 and the second part 112 can be determined according to the combined shape of multiple battery cells 20. Both the first part 111 and the second part 112 may have an opening. For example, both the first part 111 and the second part 112 may be hollow cuboids with only one open face. The openings of the first part 111 and the second part 112 are opposite to each other, and the first part 111 and the second part 112 are fastened together to form a housing 11 with a closed cavity. The housing may include a bottom plate 112a, side plates 112b, and beams. Multiple battery cells 20 are connected in parallel, series, or mixed configurations and placed inside the housing 11 formed by the fastening of the first part 111 and the second part 112.

[0138] Optionally, the battery device 10 may also include other structures, which will not be described in detail here. For example, the battery device 10 may also include a busbar component for realizing the electrical connection between multiple battery cells 20, such as parallel, series, or mixed connection. Specifically, the busbar component can realize the electrical connection between battery cells 20 by connecting the electrode terminals of the battery cells 20. Further, the busbar component can be fixed to the electrode terminals of the battery cells 20 by welding. The electrical energy of the multiple battery cells 20 can be further led out through the housing by a conductive mechanism. Optionally, the conductive mechanism may also be part of the busbar component.

[0139] The number of battery cells 20 can be set to any value depending on different power requirements. Multiple battery cells 20 can be connected in series, parallel, or mixed to achieve a larger capacity or power. Since each battery device 10 may include a large number of battery cells 20, for ease of installation, the battery cells 20 can be grouped, with each group of battery cells 20 forming a battery module. The number of battery cells 20 included in a battery module is unlimited and can be set according to requirements.

[0140] In this embodiment, the number of battery cells 20 can be set to any value according to different power requirements. Multiple battery cells 20 can be connected in series, parallel, or mixed connection to achieve a larger capacity or power. Since each battery device 10 may include a large number of battery cells 20, for ease of installation, the battery cells 20 can be grouped, with each group of battery cells 20 forming a battery module. The number of battery cells 20 included in a battery module is not limited and can be set according to requirements. The battery device 10 may include multiple battery modules, which can be connected in series, parallel, or mixed connection.

[0141] Figure 3This paper shows a schematic diagram of the structure of a battery cell 20 provided in an embodiment of this application. Figure 4 A schematic diagram of the structure of a battery cell 20 according to another embodiment of this application is shown. Figure 5 An exploded structural diagram of a battery cell 20 provided in an embodiment of this application is shown. Figures 3 to 5 As shown, the battery cell 20 in this embodiment may include: a housing 21 and an electrode assembly 22. The housing 21 has a closed receiving space, and the electrode assembly 22 is placed in the receiving space within the housing 21. The housing 21 may include a shell 211 and an end cap assembly 212. The shell 211 is a hollow structure with at least one opening; the end cap assembly 212 is used to fasten with the shell 211 to form the housing 21 with a closed receiving space.

[0142] It should be understood that the battery cell 20 in this application embodiment can be a secondary battery. A secondary battery refers to a battery cell 20 that can be recharged after being discharged to activate the active materials and continue to be used. For example, the battery cell 20 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc.

[0143] The electrode assembly 22 in this embodiment includes a positive electrode, a negative electrode, and a separator, with the separator disposed between the negative and positive electrodes. During the charging and discharging process of the battery cell 20, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, disposed between the positive and negative electrodes, serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0144] In some embodiments, the end cap assembly 212 may be a plate-like structure used to cover the opening of the housing 211. In other embodiments, the end cap assembly 212 has a similar structure to the housing 211, that is, both the housing 211 and the end cap assembly 212 are hollow structures with one opening, and the two openings are joined together to form an outer shell 21 with a closed receiving space.

[0145] It should be understood that if the end cap assembly 212 is a plate-shaped structure, the housing 211 can be a hollow structure with an opening at one or more ends. For example, if the housing 211 is a hollow structure with an opening at one end, the end cap assembly 212 can be set as one; if the housing 211 is a hollow structure with openings at opposite ends, the end cap assembly 212 can be set as two, and the two end cap assemblies 212 respectively cover the openings at both ends of the housing 211.

[0146] The outer shell 21 can be of various shapes, such as a cylinder, a cuboid, or other polyhedrons. For example, ... Figure 3 and Figure 4As shown in the embodiments of this application, the description mainly takes the outer shell 21 as a cuboid structure.

[0147] It should be understood that the end cap assembly 212 in this embodiment of the application is used to cooperate with the housing 211 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap assembly 212 can be adapted to the shape of the housing 211, such as... Figure 3 and Figure 4 As shown, the housing 211 has a cuboid structure, and the end cap assembly 212 has a rectangular plate structure that is adapted to the housing 211.

[0148] The material of the housing 211 in this embodiment may include one or more materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the end cap assembly 212 may also be one or more materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the end cap assembly 212 may be the same as or different from that of the housing 211; the materials of different walls of the housing 211 may also be the same or different.

[0149] The end cap assembly 212 in this embodiment can be any wall of the housing 21. For example, the end cap assembly 212 can be the wall with the largest area among the multiple walls included in the housing 21, or the wall with the smallest area, or it can be other walls. This embodiment is not limited to this. Alternatively, the end cap assembly 212 can also be other structures. For example, the end cap assembly 212 can also be a groove with an opening to cover the opening of the housing 211. This embodiment is not limited to this.

[0150] It should be understood that the battery cell 20 also includes electrode terminals 214. In this embodiment, the electrode terminals 214 are used for electrical connection with the electrode assembly 22 inside the battery cell 20 to output the electrical energy of the battery cell 20. Figures 3 to 5As shown, the battery cell 20 may include at least two electrode terminals 214, which may include at least one first electrode terminal 214a and at least one second electrode terminal 214b. Exemplarily, if the first electrode terminal 214a is a positive electrode terminal, it is used for electrical connection to the positive electrode tab 222a of the electrode assembly 22; if the second electrode terminal 214b is a negative electrode terminal, it is used for electrical connection to the negative electrode tab 222b of the electrode assembly 22. The first electrode terminal 214a and the positive electrode tab 222a may be directly connected or indirectly connected, as may the negative electrode terminal 214b and the negative electrode tab 222b. Exemplarily, the first electrode terminal 214a may be electrically connected to the positive electrode tab 222a via a connecting member 23, and the second electrode terminal 214b may be electrically connected to the negative electrode tab 222b via a connecting member 23. It should be understood that in the embodiments of this application, the positive electrode tab 222a and the negative electrode tab 222b can be collectively referred to as electrode tab 222.

[0151] In this embodiment, the wall of the housing 211 and the wall of the end cap assembly 212 are both referred to as the wall of the battery cell 20, wherein for Figures 3 to 5 The rectangular battery cell 20 shown has a housing 211 with a bottom wall and four side walls. The housing 211 is shaped according to the combination of one or more electrode assemblies 22. For example, the housing 211 can be a hollow cuboid, cube, or cylinder, and one face of the housing 211 has an opening to allow one or more electrode assemblies 22 to be placed inside. For example, when the housing 211 is a hollow cuboid or cube, one plane of the housing 211 is an open face, meaning that this plane has no wall, allowing communication between the inside and outside of the housing 211. When the housing 211 can be a hollow cylinder, the end face of the housing 211 is an open face, meaning that this end face has no wall, allowing communication between the inside and outside of the housing 211. An end cap assembly 212 covers the opening and connects to the housing 211 to form a closed cavity for placing the electrode assemblies 22. The housing 211 is filled with an electrolyte, such as an electrolyte solution.

[0152] In this battery cell 20, the electrode assembly 22 is the component in which the electrochemical reaction occurs. Depending on actual usage requirements, the electrode assembly 22 within the casing 211 can be one or multiple. For example, as... Figure 5 As shown, two electrode assemblies 22 are provided inside the battery cell 20. The electrode assembly 22 can be a cylinder, a cuboid, etc. If the electrode assembly 22 is a cylindrical structure, the housing 211 can also be a cylindrical structure. If the electrode assembly 22 is a cuboid structure, the housing 211 can also be a cuboid structure.

[0153] In this battery cell 20, the electrode assembly 22 is the component in which the electrochemical reaction occurs. Depending on actual usage requirements, the electrode assembly 22 within the casing 211 can be one or multiple. For example, as... Figure 5 As shown, two electrode assemblies 22 are disposed within the battery cell 20. The electrode assembly 22 can be a cylinder, a cuboid, etc. If the electrode assembly 22 is a cylindrical structure, the housing 211 can also be a cylindrical structure; if the electrode assembly 22 is a cuboid structure, the housing 211 can also be a cuboid structure. In this embodiment, the material of the housing 211 may include the following materials: copper, iron, aluminum, steel, aluminum alloy, etc.

[0154] A pressure relief mechanism 213 may also be provided on the battery cell 20. The pressure relief mechanism 213 is actuated to release the internal pressure or temperature when the internal pressure or temperature of the battery cell 20 reaches a threshold.

[0155] The pressure relief mechanism 213 can be any of the possible pressure relief mechanisms 213. For example, the pressure relief mechanism 213 can be a temperature-sensitive pressure relief mechanism, which is configured to melt when the internal temperature of the battery cell 20 with the pressure relief mechanism 213 reaches a threshold; and / or, the pressure relief mechanism 213 can be a pressure-sensitive pressure relief mechanism, which is configured to rupture when the internal gas pressure of the battery cell 20 with the pressure relief mechanism 213 reaches a threshold.

[0156] In some implementations, the end cap assembly 212 of the battery cell 20 is provided with an injection hole 216, through which electrolyte is injected into the battery cell 20 to replenish the electrolyte in the battery cell 20.

[0157] In some implementations, the battery cell 20 further includes a base plate 217 disposed inside the housing 211, with the side of the base plate 217 away from the electrode assembly 22 attached to the side of the bottom wall of the housing 211 facing the electrode assembly 22. Exemplarily, the base plate 217 may be fixedly connected to or not fixedly connected to the side of the bottom wall of the housing 211 facing the electrode assembly 22; for example, the side of the base plate 217 away from the electrode assembly 22 may be bonded to the side of the bottom wall of the housing 211 facing the electrode assembly 22.

[0158] In some implementations, the battery cell 20 may also include an insulating member 218, which is disposed within the receiving space of the housing 211. The insulating member 218 may be a hollow structure with openings at one or more ends. The receiving space within this hollow structure is used to accommodate the electrode assembly 22, thereby improving the insulation performance of the battery cell 20. It should also be understood that in some implementations, the battery cell 20 further includes an adhesive member 219, which may be disposed between the insulating member 218 and the base plate 217 for fixing the insulating member 218 and the base plate 217 together. For example, the adhesive member 219 may be... Figure 5 The L-shaped structure shown in the figure.

[0159] In some implementations, a protective member 60 may also be provided in the battery cell 20. This protective member 60 may be located on the side of the pressure relief mechanism 213 away from the electrode assembly 22, providing protection for the pressure relief mechanism 213. Exemplarily, the protective member 60 may be welded or bonded to the pressure relief mechanism 213. The protective member 60 serves to protect the pressure relief mechanism 213, reducing the risk of wear or damage during use and improving its operational stability. The material of the protective member 60 includes, but is not limited to, plastic, rubber, or silicone. The shape of the protective member 60 can be customized according to actual needs; for example, the shape of the protective member 60 may be tailored to the shape of the pressure relief mechanism 213.

[0160] Figure 6 A cross-sectional schematic diagram of a battery cell 20 provided in an embodiment of this application is shown. Figure 7 This diagram shows a partially enlarged cross-sectional view of a battery cell 20 according to an embodiment of this application. Exemplarily, Figure 7 Can be Figure 6 An enlarged cross-sectional view of part A in the cross-sectional diagram of the battery cell 20.

[0161] In some implementations, such as Figure 6 and Figure 7As shown, the battery cell 20 includes: a housing 21, an electrode assembly 22, and a pressure relief mechanism 213. The housing 211 has a first wall 215, and the first wall 215 is provided with a pressure relief hole 70 extending through the thickness direction of the first wall 215. The electrode assembly 22 is housed within the housing 211. The pressure relief mechanism 213 covers the pressure relief hole 70. The pressure relief mechanism 213 includes a pressure relief portion 2131 and a connecting portion 2132. The connecting portion 2132 is located outside the pressure relief portion 2131. A small portion is connected to the first wall 215. A weak portion 2133 is provided on the side of the pressure relief portion 2131 near the connecting portion 2132. The weak portion 2133 is configured to be destroyed to release the pressure when the temperature or pressure inside the housing 211 reaches a threshold. The pressure relief mechanism 213 also includes at least one bending portion 90 disposed between the connecting portion 2132 and the weak portion 2133. The bending portion 90 is bent relative to the connecting portion 2132. The material of the pressure relief mechanism 213 is steel or titanium alloy.

[0162] It should be understood that the housing 211 in this embodiment includes a receiving cavity 50 with an opening at one end. The electrode assembly 22 being housed within the housing 211 means that the electrode assembly 22 can be housed within the receiving cavity 50. That is, the housing 211 can be a hollow structure with an opening, and the electrode assembly 22 is housed inside the hollow structure. It should also be understood that the shape of the opening can be circular, square, or polygonal, etc. Specifically, the shape of the opening can be matched to the shape of the housing 211. For example, when the housing 211 is configured as follows... Figures 3 to 5 In the case of the square structure shown, the opening can be square. Secondly, the end cap assembly 212 can cover the opening so that the electrode assembly 22 is accommodated inside the housing 211.

[0163] It should also be understood that the first wall 215 includes, but is not limited to, the following examples: the first wall 215 may be the wall with the smallest area of ​​the housing 211 of the battery cell 20; the first wall 215 may also be the wall with the largest area of ​​the housing 211 of the battery cell 20; the first wall 215 may be the wall of the housing 211 of the battery cell 20 where the electrode terminals 214 are provided; the first wall 215 may be a wall adjacent to the wall of the battery cell 20 where the electrode terminals 214 are provided; the first wall 215 may be a wall opposite to the wall of the battery cell 20 where the electrode terminals 214 are provided.

[0164] It should also be understood that the pressure relief hole 70 provided on the first wall 215 means that the pressure relief hole 70 communicates with the receiving cavity 50 of the housing 211, that is, a through hole structure is provided on the first wall 215 as a pressure relief hole 70. The shape of the pressure relief hole 70 on the plane perpendicular to the thickness direction of the first wall 215 can be set according to actual needs. For example, the shape of the pressure relief hole 70 on the plane perpendicular to the thickness direction of the first wall 215 can be circular, elliptical, polygonal, rectangular, etc. As an example, this application embodiment does not limit this.

[0165] It should also be understood that the first wall 215 is provided with a pressure relief hole 70, which is covered by a pressure relief mechanism 213. That is, on a plane perpendicular to the thickness direction of the first wall 215, the orthographic projection of the pressure relief mechanism 213 covers the orthographic projection of the pressure relief hole 70, and the area of ​​the orthographic projection of the pressure relief mechanism 213 is greater than or equal to the area of ​​the orthographic projection of the pressure relief hole 70.

[0166] It should also be understood that the housing 211 in the embodiments of this application includes a receiving cavity 50 which can be used to receive the electrode assembly 22. The receiving cavity 50 can be an open receiving space with an opening at one or both ends. Specifically, the receiving cavity 50 can be sealed by the end cap assembly 212.

[0167] It should also be understood that the pressure relief mechanism 213 in this embodiment may include a pressure relief part 2131 and a connecting part 2132 connected to each other. The pressure relief part 2131 and the connecting part 2132 may be integrally formed or separately formed. When the pressure relief part 2131 and the connecting part 2132 are integrally formed, they may be integrally formed by stamping. When the pressure relief part 2131 and the connecting part 2132 are separately formed, they may be connected by welding.

[0168] It should also be understood that at least a portion of the connecting portion 2132 in the embodiments of this application is connected to the first wall 215, which may mean that at least a portion of the connecting portion 2132 near the first wall 215 is welded to the first wall 215 to form a weld mark 80 between the connecting portion 2132 and the first wall 215.

[0169] It should also be understood that a weak portion 2133 is provided on the side of the pressure relief portion 2131 near the connection portion 2132 in the embodiments of this application. The weak portion 2133 can be configured to be destroyed to release the pressure when the temperature or pressure inside the housing 211 reaches a threshold. Exemplarily, the weak portion 2133 can be a groove with an opening facing away from the electrode assembly 22, and the groove can be continuous or intermittent. As an example, the embodiments of this application do not limit this.

[0170] It should also be understood that the pressure relief mechanism 213 further includes at least one bent portion 90 disposed between the connecting portion 2132 and the weak portion 2133. The bent portion 90 is bent relative to the connecting portion 2132, meaning that during the welding process of the pressure relief mechanism 213 to the first wall 215, the bent portion 90 can absorb the radial thermal stress generated during welding, reducing the risk of decreased actuation performance of the pressure relief mechanism 213 due to cracking at the weak portion 2133. It should also be understood that when the pressure relief mechanism 213 is provided with multiple bent portions 90, at least two of the multiple bent portions 90 can be provided alternately or continuously. Furthermore, the bent portion 90 in the embodiments of this application can be formed by stamping or forging.

[0171] It should also be understood that the material of the pressure relief mechanism 213 in this embodiment can be steel or titanium alloy. During the welding process of the pressure relief mechanism 213 to the first wall 215, due to the high strength of the material of the pressure relief mechanism 213, i.e., the pressure relief mechanism 213 is difficult to deform, stress concentration is likely to occur at the weak part 2133 of the pressure relief mechanism 213 during the welding process. This can easily cause the pressure relief mechanism 213 to crack at the weak part 2133, resulting in premature actuation of the pressure relief mechanism 213 and reducing its performance. In this embodiment, at least one bending part 90 provided between the connecting part 2132 and the weak part 2133 can absorb the radial thermal stress generated during the welding process, reduce the risk of decreased actuation performance of the pressure relief mechanism 213 due to cracking at the weak part 2133, and improve the performance of the pressure relief mechanism 213.

[0172] In this embodiment, the pressure relief mechanism 213 of the battery cell 20 is configured to include a pressure relief portion 2131 and a connecting portion 2132. The connecting portion 2132 is located outside the pressure relief portion 2131, and at least a portion of the connecting portion 2132 is connected to the first wall 215. A weak portion 2133 is provided on the side of the pressure relief portion 2131 near the connecting portion 2132. The weak portion 2133 is configured to be broken when the temperature or pressure inside the housing 211 reaches a threshold to release the pressure. The pressure relief mechanism 213 also includes at least one bending portion 90 disposed between the connecting portion 2132 and the weak portion 2133. The bending portion 90 is bent relative to the connecting portion 2132. In this way, during the welding process of the pressure relief mechanism 213 to the first wall 215, since the material of the pressure relief mechanism 213 is steel or titanium alloy, the pressure relief mechanism 213 is not easily deformed. Stress concentration is easily generated in the weak part 2133 of the pressure relief mechanism 213. The bending portion 90 can absorb the radial thermal stress generated during the welding process, reduce the risk of the pressure relief mechanism 213 cracking in the weak part 2133 and thus reduce the risk of the pressure relief mechanism 213's actuation performance being reduced, thereby improving the performance of the pressure relief mechanism 213 and thus improving the performance of the battery cell 20.

[0173] In some implementations, such as Figure 7 As shown, along the thickness direction of the pressure relief mechanism 213, there is a height difference between the side of the bent portion 90 near the first wall 215 and the side of the bent portion 90 near the weak portion 2133.

[0174] It should be understood that, along the thickness direction of the pressure relief mechanism 213, the height difference between the side of the bent portion 90 near the first wall 215 and the side of the bent portion 90 near the weak portion 2133 can be set according to actual needs. For example, this height difference can be set based on the dimension of the pressure relief hole 70 along the thickness direction of the first wall 215 or the dimension of the first wall 215 itself, to balance the actuation performance of the pressure relief mechanism 213 and the energy density of the battery cell 20, while also balancing the manufacturing performance of the pressure relief mechanism 213 and the assembly performance of the battery cell 20.

[0175] In this embodiment, along the thickness direction of the pressure relief mechanism 213, a height difference is set between the side of the bent portion 90 near the first wall 215 and the side of the bent portion 90 near the weak portion 2133. During the welding process of the pressure relief mechanism 213 to the first wall 215, the radial thermal stress generated during the welding process is effectively absorbed by the bent portion 90, reducing the risk of a decrease in the actuation performance of the pressure relief mechanism 213 due to cracking at the weak portion 2133, thereby improving the performance of the pressure relief mechanism 213 and thus improving the performance of the battery cell 20.

[0176] Figure 8 A partially enlarged cross-sectional schematic diagram of a battery cell 20 provided in another embodiment of this application is shown.

[0177] In some implementations, such as Figure 8 As shown, the bent portion 90 is inclined relative to the thickness direction of the pressure relief mechanism 213.

[0178] It should be understood that the tilt angle of the bent portion 90 relative to the thickness direction of the pressure relief mechanism 213 in the embodiments of this application can be set according to actual needs. For example, the tilt angle of the bent portion 90 relative to the thickness direction of the pressure relief mechanism 213 can be set to 30°, 45° or 60°, etc. As an example, the embodiments of this application do not limit this.

[0179] In this embodiment, by tilting the bending portion 90 relative to the thickness direction of the pressure relief mechanism 213, during the welding process of the pressure relief mechanism 213 to the first wall 215, the bending portion 90 effectively absorbs the radial thermal stress generated during the welding process, while reducing the maximum size of the pressure relief mechanism 213 along the thickness direction, thereby improving the space utilization rate inside the casing 211 of the battery cell 20, facilitating the processing and manufacturing of the pressure relief mechanism 213, and thus improving the performance of the battery cell 20.

[0180] Figure 9 A partially enlarged cross-sectional schematic diagram of a battery cell 20 provided in another embodiment of this application is shown. Figure 10 A partially enlarged cross-sectional schematic diagram of a battery cell 20 provided in another embodiment of this application is shown. Figure 11 A partially enlarged cross-sectional schematic diagram of a battery cell 20 provided in another embodiment of this application is shown. Figure 12 A partially enlarged cross-sectional schematic diagram of a battery cell 20 provided in another embodiment of this application is shown. Figure 13 A partially enlarged cross-sectional schematic diagram of a battery cell 20 provided in another embodiment of this application is shown.

[0181] In some implementations, such as Figures 9 to 13 As shown, at least one of the bending portions 90 includes an adjacent first bending portion 901 and a second bending portion 902. The first bending portion 901 and the second bending portion 902 form a protrusion 910 that protrudes toward or away from the electrode assembly 22. The protrusion 910 is disposed around the pressure relief portion 2131.

[0182] It should be understood that the adjacent first bends 901 and second bends 902 may be provided continuously or at intervals. For example, when the adjacent first bends 901 and second bends 902 are provided continuously, they may be formed together in a cross-section perpendicular to the thickness direction of the battery cell 20. Figure 9 The protrusion 910 shown has a V-shaped groove formed on the side facing the electrode assembly 22. When adjacent first bends 901 and second bends 902 are spaced apart, they can be formed together in a cross-section perpendicular to the thickness direction of the battery cell 20. Figures 10 to 13 The protrusion 910 shown in the figure has a groove structure 911 formed on the side facing the electrode assembly 22.

[0183] It should also be understood that the protrusion 910 surrounding the pressure relief portion 2131 can mean that, on a plane perpendicular to the thickness direction of the first wall 215, the protrusion 910 can be configured as an annular structure and surround the pressure relief portion 2131.

[0184] In this embodiment, by configuring at least one of the bending portions 90 to include adjacent first bending portions 901 and second bending portions 902, and the first bending portion 901 and the second bending portion 902 forming a protrusion 910 protruding in a direction toward or away from the electrode assembly 22, the protrusion 910 can absorb the radial thermal stress generated during the welding process of welding the pressure relief mechanism 213 to the first wall 215, thereby reducing the risk of a decrease in the actuation performance of the pressure relief mechanism 213 due to cracking at the weak part 2133, thus improving the performance of the pressure relief mechanism 213 and thereby improving the performance of the battery cell 20.

[0185] In some implementations, such as Figure 9 , Figure 11 and Figure 13 As shown, the protrusion 910 protrudes in a direction away from the electrode assembly 22.

[0186] It should be understood that the size of the protrusion 910 protruding away from the electrode assembly 22 can be set according to actual needs. For example, the size of the protrusion 910 protruding away from the electrode assembly 22 can be set according to the thickness of the first wall 215. Secondly, by setting the protrusion 910 to protrude away from the electrode assembly 22, the space occupied by the protrusion 910 inside the battery cell 20 can be reduced, thereby improving the space utilization rate inside the casing 211 of the battery cell 20 and increasing the energy density of the battery cell 20.

[0187] In this embodiment, by setting the protrusion 910 to protrude in a direction away from the electrode assembly 22, the impact of the protrusion 910 on the interior of the housing 211 of the battery cell 20 is reduced, and the space utilization rate inside the housing 211 of the battery cell 20 is improved. During the process of welding the pressure relief mechanism 213 to the first wall 215, the protrusion 910 can absorb the radial thermal stress generated during the welding process, reducing the risk of a decrease in the actuation performance of the pressure relief mechanism 213 due to cracking at the weak part 2133, thereby improving the performance of the pressure relief mechanism 213 and thus improving the performance of the battery cell 20.

[0188] In some implementations, such as Figures 9 to 13 As shown, in the thickness direction of the first wall 215, the dimension D1 of the protrusion 910 satisfies: 0.05mm≤D1≤0.5mm.

[0189] It should be understood that, in the thickness direction of the first wall 215, the dimension D1 of the protrusion 910 can refer to the maximum dimension, minimum dimension, or average dimension of the protrusion 910 along the thickness direction of the first wall 215.

[0190] For example, in the thickness direction of the first wall 215, the size D1 of the protrusion 910 can be set to: 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, etc., or its value is within the range obtained by any combination of the above two values.

[0191] In some other implementations, the dimension D1 of the protrusion 910 in the thickness direction of the first wall 215 can also satisfy: 0.1mm≤D1≤0.3mm.

[0192] In this embodiment, in the thickness direction of the first wall 215, by setting the size D1 of the protrusion 910 to satisfy: 0.05mm≤D1≤0.5mm, during the welding process of the pressure relief mechanism 213 to the first wall 215, the radial thermal stress generated during the welding process of the protrusion 910 and the performance of the pressure relief mechanism 213 are taken into account. This reduces the risk of the pressure relief mechanism 213's actuation performance decreasing due to cracking at the weak part 2133, thereby improving the performance of the battery cell 20.

[0193] In some implementations, such as Figure 9 , Figure 11 and Figure 13 As shown, the protrusion 910 has a groove structure 911 with an opening facing the electrode assembly 22 on the side facing the electrode assembly 22.

[0194] It should be understood that the groove structure 911 can be formed by two adjacent bends 90, namely, a first bend 901 and a second bend 902 that are opposite to each other and spaced apart. On a plane perpendicular to the thickness direction of the first wall 215, the shape of the groove structure 911 can be set as an annular ring. For example, the shape of the groove structure 911 can be set as a rectangular ring or a circular ring, and the rectangular ring or circular ring surrounds the pressure relief part 2131.

[0195] In this embodiment, by forming a groove structure 911 with an opening facing the electrode assembly 22 on the side of the protrusion 910 facing the electrode assembly 22, the radial thermal stress generated during the welding process of welding the pressure relief mechanism 213 to the first wall 215 can be effectively absorbed by the protrusion 910 containing the groove structure 911. This reduces the risk of a decrease in the actuation performance of the pressure relief mechanism 213 due to cracking at the weak part 2133, thereby improving the performance of the pressure relief mechanism 213 and thus improving the performance of the battery cell 20.

[0196] In some implementations, such as Figure 9 , Figure 11 and Figure 13 As shown, in the thickness direction perpendicular to the first wall 215, the dimension D2 of the groove structure 911 satisfies: 0.1mm≤D2≤2mm.

[0197] It should be understood that, in the thickness direction perpendicular to the first wall 215, the dimension D2 of the groove structure 911 can refer to the maximum, minimum, or average dimension of the groove structure 911 in the thickness direction perpendicular to the first wall 215.

[0198] For example, in the thickness direction perpendicular to the first wall 215, the dimension D2 of the groove structure 911 can be set to: 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2mm, etc., or its value is within the range obtained by any combination of the above two values.

[0199] In some other implementations, the dimension D2 of the groove structure 911 in the thickness direction perpendicular to the first wall 215 can also satisfy: 0.2mm≤D2≤0.5mm.

[0200] In this embodiment, in the thickness direction perpendicular to the first wall 215, by setting the dimension D2 of the groove structure 911 to satisfy: 0.1mm≤D2≤2mm, during the welding process of the pressure relief mechanism 213 to the first wall 215, the radial thermal stress generated during the welding process of the protrusion 910 containing the groove structure 911 is taken into account, and the performance of the pressure relief mechanism 213 is reduced. This reduces the risk of a decrease in the actuation performance of the pressure relief mechanism 213 due to cracking at the weak part 2133, and at the same time facilitates the processing and manufacturing of the pressure relief mechanism 213, thereby improving the performance of the battery cell 20.

[0201] In some implementations, such as Figure 9 , Figure 11 and Figure 13 As shown, in the thickness direction perpendicular to the first wall 215, the dimension D3 between the inner wall of the groove structure 911 on the side away from the pressure relief part 2131 and the surface of the protrusion 910 on the side away from the pressure relief part 2131 satisfies: 0.05mm≤D3≤1mm.

[0202] It should be understood that, in the thickness direction perpendicular to the first wall 215, the dimension D3 between the inner wall of the groove structure 911 on the side away from the pressure relief portion 2131 and the surface of the protrusion 910 on the side away from the pressure relief portion 2131 can refer to the maximum, minimum, or average dimension between the inner wall of the groove structure 911 on the side away from the pressure relief portion 2131 and the surface of the protrusion 910 on the side away from the pressure relief portion 2131.

[0203] For example, in the thickness direction perpendicular to the first wall 215, the dimension D3 between the inner wall of the groove structure 911 on the side away from the pressure relief part 2131 and the surface of the protrusion 910 on the side away from the pressure relief part 2131 can be set to: 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc., or its value is within the range obtained by any combination of the above two values.

[0204] In some other implementations, the dimension D3 between the inner wall of the groove structure 911 on the side away from the pressure relief part 2131 and the surface of the protrusion 910 on the side away from the pressure relief part 2131 in the thickness direction perpendicular to the first wall 215 can also satisfy: 0.1mm≤D3≤0.3mm.

[0205] In this embodiment, in the thickness direction perpendicular to the first wall 215, by setting the dimension D3 between the inner wall of the groove structure 911 on the side away from the pressure relief portion 2131 and the surface of the protrusion 910 on the side away from the pressure relief portion 2131 to satisfy: 0.05mm≤D3≤1mm, during the process of welding the pressure relief mechanism 213 to the first wall 215, the protrusion 910 can effectively absorb the radial thermal stress generated during the welding process, reduce the risk of the pressure relief mechanism 213's actuation performance decreasing due to cracking at the weak portion 2133, and improve the performance of the battery cell 20.

[0206] In some implementations, such as Figure 9 , Figure 11 and Figure 13 As shown, in the thickness direction perpendicular to the first wall 215, the dimension D4 between the inner wall of the groove structure 911 away from the pressure relief part 2131 and the surface of the connecting part 2132 near the pressure relief hole 70 satisfies: 0.3mm≤D4≤10mm.

[0207] It should be understood that, in the thickness direction perpendicular to the first wall 215, the dimension D4 between the inner wall of the groove structure 911 on the side away from the pressure relief part 2131 and the surface of the connecting part 2132 on the side near the pressure relief hole 70 can refer to the maximum, minimum, or average dimension between the inner wall of the groove structure 911 on the side away from the pressure relief part 2131 and the surface of the connecting part 2132 on the side near the pressure relief hole 70.

[0208] For example, in the thickness direction perpendicular to the first wall 215, the dimension D4 between the inner wall of the groove structure 911 away from the pressure relief part 2131 and the surface of the connecting part 2132 near the pressure relief hole 70 can be set to: 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc., or its value is within the range obtained by any combination of the above two values.

[0209] In some other implementations, the dimension D4 between the inner wall of the groove structure 911 away from the pressure relief part 2131 and the surface of the connecting part 2132 near the pressure relief hole 70 in the thickness direction perpendicular to the first wall 215 can also satisfy: 0.5mm≤D4≤5mm.

[0210] In this embodiment, in the thickness direction perpendicular to the first wall 215, by setting the dimension D4 between the inner wall of the groove structure 911 away from the pressure relief portion 2131 and the surface of the connecting portion 2132 near the pressure relief hole 70 to satisfy: 0.3mm≤D4≤10mm, during the welding process of the pressure relief mechanism 213 to the first wall 215, the connection strength between the first wall 215 and the pressure relief mechanism 213 and the ability of the protrusion 910 to absorb the radial thermal stress generated during the welding process are taken into account. This reduces the risk of a decrease in the actuation performance of the pressure relief mechanism 213 due to cracking at the weak portion 2133, thereby improving the performance of the battery cell 20.

[0211] Figure 14 A partially enlarged cross-sectional schematic diagram of a battery cell 20 provided in another embodiment of this application is shown. Figure 15 A partially enlarged cross-sectional schematic diagram of a battery cell 20 provided in another embodiment of this application is shown. Figure 16 A partially enlarged cross-sectional schematic diagram of a battery cell 20 provided in another embodiment of this application is shown.

[0212] In some implementations, such as Figures 14 to 16 As shown, the inner wall of the groove structure 911 on the side away from the pressure relief hole 70 is the part of the pressure relief portion 2131 that is close to the pressure relief hole 70.

[0213] It should be understood that, in the embodiments of this application, the inner wall of the groove structure 911 on the side away from the pressure relief hole 70 is set as the part of the pressure relief portion 2131 near the pressure relief hole 70. That is, the groove structure 911 has a larger dimension in the thickness direction perpendicular to the first wall 215. During the process of welding the pressure relief mechanism 213 to the first wall 215, the protrusion 910 can effectively absorb the radial thermal stress generated during the welding process, thereby reducing the risk of the pressure relief mechanism 213's actuation performance decreasing due to cracking in the weak part 2133.

[0214] In this embodiment, by using the inner wall of the groove structure 911 on the side away from the pressure relief hole 70 as the part of the pressure relief portion 2131 near the pressure relief hole 70, during the welding process of the pressure relief mechanism 213 to the first wall 215, the ability of the protrusion 910 to absorb the radial thermal stress generated during the welding process and the manufacturing performance of the pressure relief mechanism 213 are taken into account. This reduces the risk of a decrease in the actuation performance of the pressure relief mechanism 213 due to cracking at the weak part 2133, thereby improving the performance of the battery cell 20.

[0215] In some implementations, such as Figure 14 and Figure 15The pressure relief hole 70 includes a first hole 710 and a second hole 720 distributed in a stepped manner. One end of the first hole 710 is formed on the surface of the first wall 215 facing the electrode assembly 22. The second hole 720 is located on the side of the first hole 710 away from the electrode assembly 22. The diameter of the first hole 710 is smaller than the diameter of the second hole 720. The side of the connecting portion 2132 away from the pressure relief portion 2131 is welded to the inner wall of the second hole 720.

[0216] It should be understood that the shapes of the first hole 710 and the second hole 720 included in the pressure relief hole 70 in this application embodiment can be set according to actual needs. For example, on a plane perpendicular to the thickness direction of the first wall 215, the shapes of the first hole 710 and the second hole 720 can be circular, elliptical, polygonal, rectangular, etc. As an example, this application embodiment does not limit this.

[0217] It should also be understood that the side of the connecting part 2132 away from the pressure relief part 2131 is welded to the inner wall of the second hole 720 to increase the actuation space of the pressure relief mechanism 213, improve the actuation performance of the pressure relief mechanism 213, and facilitate the assembly of the pressure relief mechanism 213.

[0218] In this embodiment, the pressure relief hole 70 is configured to include a first hole 710 and a second hole 720 distributed in a stepped manner. One end of the first hole 710 is formed on the surface of the first wall 215 facing the electrode assembly 22, and the second hole 720 is located on the side of the first hole 710 away from the electrode assembly 22. The diameter of the first hole 710 is smaller than the diameter of the second hole 720. The side of the connecting portion 2132 away from the pressure relief portion 2131 is welded to the inner wall of the second hole 720. This is to balance the connection strength and assembly performance between the pressure relief mechanism 213 and the first wall 215, thereby improving the performance of the battery cell 20.

[0219] In some implementations, such as Figure 14 and Figure 15 As shown, a first surface 2151 is formed between the first hole 710 and the second hole 720, away from the electrode assembly 22, and at least a portion of the surface of the connecting portion 2132 facing the electrode assembly 22 abuts against the first surface 2151.

[0220] It should be understood that at least a portion of the surface of the connection portion 2132 facing the electrode assembly 22 can abut against the first surface 2151 to improve the connection strength between the connection portion 2132 and the first wall 215, thereby improving the connection strength between the pressure relief mechanism 213 and the first wall 215, and facilitating the assembly of the pressure relief mechanism 213.

[0221] In this embodiment, a first surface 2151 is formed between the first hole 710 and the second hole 720, away from the electrode assembly 22. By setting at least a portion of the surface of the connecting portion 2132 facing the electrode assembly 22 to abut against the first surface 2151, the connection strength between the pressure relief mechanism 213 and the first wall 215 and the performance of the pressure relief mechanism 213 are taken into account, thereby improving the performance of the battery cell 20.

[0222] In some implementations, such as Figure 15 As shown, the surface of the protrusion 910 on the side away from the electrode assembly 22 does not protrude from the surface of the first wall 215 on the side away from the electrode assembly 22.

[0223] It should be understood that, such as Figure 15 As shown, the fact that the surface of the protrusion 910 away from the electrode assembly 22 does not protrude from the surface of the first wall 215 away from the electrode assembly 22 can mean that, along the thickness direction of the first wall 215, the portion of the protrusion 910 protruding towards the side away from the electrode assembly 22 does not protrude from the surface of the first wall 215 away from the electrode assembly 22. During the use of the battery cell 20, the impact of external impact on the protrusion 910 is reduced, so as to balance the performance of the pressure relief mechanism 213 in use and manufacturing performance.

[0224] For example, the pressure relief hole 70 also includes a third hole 730, which is disposed on the side of the second hole 720 away from the electrode assembly 22, and the diameter of the third hole 730 is larger than the diameter of the second hole 720. That is, the first hole 710, the second hole 720 and the third hole 730 are distributed in a stepped manner. The surface of the protrusion 910 away from the electrode assembly 22 does not protrude from the surface of the first wall 215 away from the electrode assembly 22. This can mean that the portion of the protrusion 910 protruding towards the side away from the electrode assembly 22 does not protrude from the surface of the third hole 730 away from the electrode assembly 22. It should also be understood that a protective member 60 may be provided on the inner wall of the third hole 730. The protective member 60 may be welded or bonded to the inner wall of the third hole 730. There is a distance between the surface of the protrusion 910 away from the electrode assembly 22 and the surface of the protective member 60 facing the electrode assembly 22, that is, the protrusion 910 and the protective member 60 do not contact each other, so as to balance the performance of the pressure relief mechanism 213 and the performance of the protective member 60.

[0225] In this embodiment, by setting the surface of the protrusion 910 away from the electrode assembly 22 to not protrude from the surface of the first wall 215 away from the electrode assembly 22, the impact of external impact on the protrusion 910 during the use of the battery cell 20 is reduced, so that the pressure relief mechanism 213 can be actuated normally, thereby improving the performance of the pressure relief mechanism 213 and thus improving the performance of the battery cell 20.

[0226] In some implementations, such as Figures 9 to 16 As shown, along the thickness direction of the first wall 215, the dimension D5 of the connecting part 2132 satisfies: 0.05mm≤D5≤1mm.

[0227] It should be understood that, along the thickness direction of the first wall 215, the dimension D5 of the connecting part 2132 may refer to the maximum dimension, minimum dimension, or average dimension of the connecting part 2132 in the thickness direction of the first wall 215.

[0228] For example, along the thickness direction of the first wall 215, the dimension D5 of the connecting portion 2132 can be set to: 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc., or its value is within the range obtained by any combination of the above two values.

[0229] In this embodiment, by setting the thickness D5 of the connecting portion 2132 to satisfy 0.05mm≤D5≤1mm, during the welding process of the pressure relief mechanism 213 to the first wall 215, the ability of the protrusion 910 to absorb the radial thermal stress generated during the welding process and the manufacturing performance of the pressure relief mechanism 213 are taken into account. This reduces the risk of a decrease in the actuation performance of the pressure relief mechanism 213 due to cracking at the weak part 2133, and at the same time reduces the space occupied by the pressure relief mechanism 213 inside the housing 211, thereby improving the performance of the battery cell 20.

[0230] In some implementations, such as Figures 9 to 16 As shown, in the thickness direction of the first wall 215, the dimension D6 of the weak part 2133 satisfies: 0.01mm≤D6≤0.25mm.

[0231] It should be understood that, in the thickness direction of the first wall 215, the dimension D6 of the weak portion 2133 can refer to the maximum, minimum, or average dimension of the weak portion 2133 in the thickness direction of the first wall 215.

[0232] For example, in the thickness direction of the first wall 215, the dimension D6 of the weak portion 2133 can be set to: 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, etc., or its value is within the range obtained by any combination of the above two values.

[0233] In this embodiment of the application, in the thickness direction of the first wall 215, the dimension D6 of the weak part 2133 is set to satisfy: 0.01mm≤D6≤0.25mm, so as to take into account both the actuation performance and manufacturing performance of the pressure relief mechanism 213, thereby improving the performance of the battery cell 20.

[0234] In some implementations, such as Figures 12 to 16 As shown, the pressure relief section 2131 is a raised structure that protrudes in the direction of the electrode assembly 22 or away from the electrode assembly 22.

[0235] It should be understood that the pressure relief portion 2131 in this embodiment is a raised structure protruding towards or away from the electrode assembly 22, i.e., the pressure relief portion 2131 is not flat. For example, the entire area of ​​the pressure relief portion 2131 is a raised structure protruding towards the electrode assembly 22; or, the entire area of ​​the pressure relief portion 2131 is a raised structure protruding away from the electrode assembly 22; or, a portion of the pressure relief portion 2131 is a raised structure protruding towards the electrode assembly 22, and a portion of the pressure relief portion 2131 is a raised structure protruding away from the electrode assembly 22. For example, the pressure relief portion 2131 can be a wavy structure. As an example, this embodiment is not limited to this.

[0236] In this embodiment, during the use of the battery cell 20, the electrode assembly 22 repeatedly expands and contracts, and the weak part 2133 of the pressure relief mechanism 213 is repeatedly stretched and contracted, which is prone to fatigue. The pressure relief part 2131 is set as a raised structure protruding in the direction of the electrode assembly 22 or away from the electrode assembly 22, which can play a buffering role, bear part of the force, reduce the deformation of the weak part 2133, reduce the fatigue of the weak part 2133, improve the actuation performance of the pressure relief mechanism 213, and thus improve the performance of the battery cell 20.

[0237] In some implementations, the pressure relief part 2131 and the connecting part 2132 are integrally formed.

[0238] For example, when the pressure relief part 2131 and the connecting part 2132 are integrally formed, the pressure relief part 2131 and the connecting part 2132 can be integrally formed by stamping.

[0239] In this embodiment, by making the pressure relief part 2131 and the connecting part 2132 integrally formed, the actuation performance and manufacturing performance of the pressure relief mechanism 213 are taken into account, thereby improving the performance of the battery cell 20.

[0240] According to some embodiments of this application, this application also provides a battery device 10, including a plurality of battery cells 20, wherein the battery cell 20 is the battery cell 20 in any of the above embodiments.

[0241] According to some embodiments of this application, this application also provides an electrical device, including the battery device 10 in any of the above embodiments, the battery device 10 being used to provide electrical energy to the electrical device. Specifically, the electrical device can be the above... Figure 1 The vehicle 1 shown can also be any electrical device that uses the battery device 10.

[0242] The power supply device can be any of the aforementioned devices or systems that utilize battery device 10.

[0243] According to some embodiments of this application, this application also provides an energy storage device, including the battery device 10 in any of the above embodiments, the battery device 10 being used to store electrical energy for the energy storage device.

[0244] Based on some embodiments of this application, see again the above. Figures 7 to 16As shown, a battery cell 20 is provided, comprising: a housing 211, an electrode assembly 22, and a pressure relief mechanism 213. The housing 211 has a first wall 215, and the first wall 215 is provided with a pressure relief hole 70 extending through the thickness direction of the first wall 215. The electrode assembly 22 is accommodated within the housing 211. The pressure relief mechanism 213 covers the pressure relief hole 70. The pressure relief mechanism 213 includes a pressure relief portion 2131 and a connecting portion 2132. The connecting portion 2132 is located outside the pressure relief portion 2131. At least a portion of 2132 is connected to the first wall 215. A weak portion 2133 is provided on the side of the pressure relief portion 2131 near the connecting portion 2132. The weak portion 2133 is configured to be broken when the temperature or pressure inside the housing 211 reaches a threshold to release the pressure. The pressure relief mechanism 213 also includes at least one bend 90 disposed between the connecting portion 2132 and the weak portion 2133, the bend 90 being bent relative to the connecting portion 2132. The pressure relief mechanism 213 is made of steel or titanium alloy. Along the thickness direction of the pressure relief mechanism 213, there is a height difference between the side of the bend 90 near the first wall 215 and the side of the bend 90 near the weak portion 2133. At least one of the bending portions 90 includes an adjacent first bending portion 901 and a second bending portion 902, wherein the first bending portion 901 and the second bending portion 902 form a protrusion 910 that protrudes toward or away from the electrode assembly 22, the protrusion 910 is disposed around the pressure relief portion 2131, and the protrusion 910 protrudes toward or away from the electrode assembly 22.

[0245] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The housing (211) has a first wall (215) and a pressure relief hole (70) extending through the thickness direction of the first wall (215). Electrode assembly (22), which is housed within the housing (211); A pressure relief mechanism (213) covering the pressure relief hole (70) includes a pressure relief part (2131) and a connecting part (2132), the connecting part (2132) being located outside the pressure relief part (2131), at least a portion of the connecting part (2132) being connected to the first wall (215), a weak part (2133) being provided on the side of the pressure relief part (2131) near the connecting part (2132), the weak part (2133) being configured to be destroyed to release the pressure when the temperature or pressure inside the housing (211) reaches a threshold. The pressure relief mechanism (213) further includes at least one bending portion (90) disposed between the connecting portion (2132) and the weak portion (2133), the bending portion (90) being bent relative to the connecting portion (2132), and the material of the pressure relief mechanism (213) being steel or titanium alloy.

2. The battery cell according to claim 1, characterized in that, Along the thickness direction of the pressure relief mechanism (213), there is a height difference between the side of the bent portion (90) near the first wall (215) and the side of the bent portion (90) near the weak portion (2133).

3. The battery cell according to claim 2, characterized in that, The bent portion (90) is inclined relative to the thickness direction of the pressure relief mechanism (213).

4. The battery cell according to claim 2, characterized in that, At least one of the bending portions (90) includes an adjacent first bending portion (901) and a second bending portion (902), the first bending portion (901) and the second bending portion (902) forming a protrusion (910) protruding toward or away from the electrode assembly (22), the protrusion (910) being disposed around the pressure relief portion (2131).

5. The battery cell according to claim 4, characterized in that, The protrusion (910) protrudes in a direction away from the electrode assembly (22).

6. The battery cell according to claim 5, characterized in that, In the thickness direction of the first wall (215), the dimension D1 of the protrusion (910) satisfies: 0.05mm≤D1≤0.5mm.

7. The battery cell according to claim 5, characterized in that, The protrusion (910) has a groove structure (911) with an opening facing the electrode assembly (22) on the side facing the electrode assembly (22).

8. The battery cell according to claim 7, characterized in that, In the thickness direction perpendicular to the first wall (215), the dimension D2 of the groove structure (911) satisfies: 0.1mm≤D2≤2mm.

9. The battery cell according to claim 7, characterized in that, In the thickness direction perpendicular to the first wall (215), the dimension D3 between the inner wall of the groove structure (911) on the side away from the pressure relief part (2131) and the surface of the protrusion (910) on the side away from the pressure relief part (2131) satisfies: 0.05mm≤D3≤1mm.

10. The battery cell according to claim 7, characterized in that, In the thickness direction perpendicular to the first wall (215), the dimension D4 between the inner wall of the groove structure (911) away from the pressure relief part (2131) and the surface of the connecting part (2132) near the pressure relief hole (70) satisfies: 0.3mm≤D4≤10mm.

11. The battery cell according to claim 7, characterized in that, The inner wall of the groove structure (911) on the side away from the pressure relief hole (70) is the part of the pressure relief section (2131) near the pressure relief hole (70).

12. The battery cell according to any one of claims 1 to 11, characterized in that, The pressure relief hole (70) includes a first hole (710) and a second hole (720) distributed in a stepped manner. One end of the first hole (710) is formed on the surface of the first wall (215) facing the electrode assembly (22). The second hole (720) is located on the side of the first hole (710) away from the electrode assembly (22). The diameter of the first hole (710) is smaller than the diameter of the second hole (720). The side of the connecting part (2132) away from the pressure relief part (2131) is welded to the inner wall of the second hole (720).

13. The battery cell according to claim 12, characterized in that, A first surface (2151) is formed between the first hole (710) and the second hole (720) away from the electrode assembly (22), and at least a portion of the surface of the connecting portion (2132) facing the electrode assembly (22) abuts against the first surface (2151).

14. A battery device, characterized in that, include: Multiple battery cells, wherein the battery cells are as described in any one of claims 1 to 13.

15. An electrical appliance, characterized in that, include: The battery device as claimed in claim 14, wherein the battery device is used to provide electrical energy to the electrical device.

16. An energy storage device, characterized in that, include: The battery device of claim 14, wherein the battery device is used to store electrical energy for the energy storage device.

Images