Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device, and relates to the field of batteries. The battery monomer comprises a shell and a pressure relief mechanism, the shell is provided with a wall part, and the pressure relief mechanism is arranged on the wall part. The base material of the pressure relief mechanism is iron. The pressure relief mechanism is provided with a first groove, and the pressure relief mechanism is configured to be cracked along at least part of the first groove when the pressure in the shell reaches a threshold value so as to release the pressure. Wherein the first groove is provided with a first groove bottom surface, the first groove bottom surface is an arc surface which is sunken in the direction away from a groove opening of the first groove, the arc surface is in an arc shape on the cross section of the first groove, and the cross section is perpendicular to the extending direction of the first groove. The groove bottom surface of the first groove is arranged to be the arc surface which is recessed along the direction far away from the groove opening of the first groove, so that material flowing is facilitated during punch forming of the first groove, stress concentration can be relieved, the bursting pressure of a plurality of battery monomers can be kept consistent during manufacturing of the plurality of battery monomers, and the reliability of the battery monomers can be improved.

Description

Technical Field

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

[0002] Batteries are widely used in new energy applications, such as electric vehicles and new energy vehicles. These have become a new trend in the automotive industry. The development of battery technology requires consideration of multiple design factors, including performance parameters such as energy density, discharge capacity, and charge / discharge rate. Furthermore, battery reliability must be considered. However, current battery reliability is relatively poor. Utility Model Content

[0003] The purpose of the embodiments of the present application is to provide a battery cell, a battery device, and an electrical device, which are intended to improve the problem of poor reliability of batteries in related technologies.

[0004] In a first aspect, an embodiment of the present application provides a battery cell, comprising a shell and a pressure relief mechanism, the shell having a wall portion; the pressure relief mechanism is arranged on the wall portion, the base material of the pressure relief mechanism is iron, the pressure relief mechanism is provided with a first groove, and the pressure relief mechanism is configured to crack along at least part of the first groove when the pressure inside the shell reaches a threshold value to release the pressure; wherein the first groove has a first groove bottom surface, the first groove bottom surface is an arc surface that is concave in a direction away from the notch of the first groove, the arc surface is arc-shaped in the cross section of the first groove, and the cross section is perpendicular to the extension direction of the first groove.

[0005] In the above technical solution, the base material of the pressure relief mechanism is iron, which can effectively improve the structural strength of the pressure relief mechanism and reduce the risk of premature valve opening and pressure relief, thereby improving the service life and reliability of the battery cells. By configuring the first groove bottom surface of the first groove to be an arc surface that is concave in the direction away from the notch of the first groove, material flow is facilitated during the stamping and forming of the first groove, which helps to alleviate stress concentration and maintain consistent burst pressure of multiple battery cells during manufacturing, thereby improving the reliability of the battery cells.

[0006] As an optional technical solution of the embodiment of the present application, the arc surface is a circular arc surface.

[0007] In the above technical solution, by setting the bottom surface of the first groove of the first groove to be an arc surface that is concave in the direction away from the groove mouth of the first groove, it is easier to flow the material when stamping the first groove, which is more conducive to alleviating stress concentration, and is more conducive to keeping the bursting pressure of multiple battery cells consistent when manufacturing multiple battery cells, which is more conducive to improving the reliability of the battery cells.

[0008] As an optional technical solution of the embodiment of the present application, the arc surface defines a notch of the first groove.

[0009] In the above technical solution, the arc surface defines the notch of the first groove, and the cross-section of the first groove is arc-shaped as a whole, which is convenient for material flow when the first groove is stamped and formed, is beneficial to alleviating stress concentration, is beneficial to keeping the bursting pressure of multiple battery cells consistent when manufacturing multiple battery cells, and is beneficial to improving the reliability of the battery cells.

[0010] As an optional technical solution of an embodiment of the present application, the first groove includes a first groove side surface and a second groove side surface. Along the width direction of the first groove, the first groove side surface and the second groove side surface are arranged opposite to each other, and the first groove bottom surface connects the first groove side surface and the second groove side surface.

[0011] In the above technical solution, the bottom surface of the first groove connects the first groove side surface and the second groove side surface, the first groove side surface and the second groove side surface are flat, and the bottom surface of the first groove is an arc surface, which makes it convenient to keep the width of the first groove small when the depth of the first groove is large, so as to facilitate controlling the bursting pressure of the pressure relief mechanism.

[0012] As an optional technical solution of an embodiment of the present application, the first groove side surface and the second groove side surface define a notch of the first groove.

[0013] In the above technical solution, the first groove side surface and the second groove side surface define the notch of the first groove, so that the cross-sectional shape of the first groove is relatively simple, which is beneficial to reducing the stress between the groove side surface and the bottom surface of the first groove, alleviating stress concentration, and is beneficial to keeping the bursting pressure of multiple battery cells consistent when manufacturing multiple battery cells, which is beneficial to improving the reliability of the battery cells.

[0014] As an optional technical solution of an embodiment of the present application, the first groove side surface and the second groove side surface are both inclined, and the distance between the first groove side surface and the second groove side surface gradually decreases from the groove opening to the bottom surface of the first groove.

[0015] In the above technical solution, by making the first groove side surface and the second groove side surface both inclined, the distance between the first groove side surface and the second groove side surface gradually decreases from the groove mouth to the bottom surface of the first groove, which is beneficial to the flow of material when stamping the first groove and reducing stress concentration.

[0016] As an optional technical solution of an embodiment of the present application, the side surface of the first groove is parallel to the side surface of the second groove.

[0017] In the above technical solution, when the first groove side surface and the second groove side surface are parallel, the width of the first groove is easier to control, which is beneficial to keep the bursting pressure of multiple battery cells consistent when manufacturing multiple battery cells, and is beneficial to improving the reliability of the battery cells.

[0018] As an optional technical solution of an embodiment of the present application, the first groove also includes a third groove side surface and a fourth groove side surface. Along the width direction of the first groove, the third groove side surface and the fourth groove side surface are arranged opposite to each other, and the first groove side surface connects one end of the first groove bottom surface and the third groove side surface, and the second groove side surface connects the other end of the first groove bottom surface and the fourth groove side surface.

[0019] In the above technical solution, by providing the third groove side surface and the fourth groove side surface, it is convenient to keep the width of the first groove small when the depth of the first groove is large, so as to facilitate controlling the bursting pressure of the pressure relief mechanism.

[0020] As an optional technical solution of the embodiment of the present application, the third groove side surface and the fourth groove side surface define a notch of the first groove.

[0021] In the above technical solution, the third groove side surface and the fourth groove side surface define the notch of the first groove, so that the cross-sectional shape of the first groove is relatively simple, which is beneficial to reducing the stress between two adjacent groove side surfaces and between the groove side surface and the bottom surface of the first groove, alleviating stress concentration, and is beneficial to keeping the bursting pressure of multiple battery cells consistent when manufacturing multiple battery cells, which is beneficial to improving the reliability of the battery cells.

[0022] As an optional technical solution of an embodiment of the present application, the first groove side surface is parallel to the second groove side surface; the third groove side surface and the fourth groove side surface are both inclined, and the distance between the third groove side surface and the fourth groove side surface gradually decreases from the groove opening to the direction of the bottom surface of the first groove.

[0023] In the above technical solution, by making the first groove side parallel to the second groove side, the third groove side and the fourth groove side are both inclined, and the distance between the third groove side and the fourth groove side gradually decreases from the groove mouth to the bottom surface of the first groove, which is beneficial to the flow of material when stamping the first groove and reducing stress concentration.

[0024] As an optional technical solution of an embodiment of the present application, the first groove side surface and the second groove side surface are both inclined, and along the thickness direction of the wall portion, the distance between the first groove side surface and the second groove side surface gradually decreases from the groove opening to the direction of the first groove bottom surface; the third groove side surface is parallel to the fourth groove side surface.

[0025] In the above technical solution, by making the first groove side surface and the second groove side surface both inclined, along the thickness direction of the wall portion, the distance between the first groove side surface and the second groove side surface gradually decreases from the groove opening to the bottom surface of the first groove, and the third groove side surface is parallel to the fourth groove side surface, so that the width of the first groove is easier to control, which is beneficial to keep the bursting pressure of multiple battery cells consistent when manufacturing multiple battery cells, and is beneficial to improving the reliability of the battery cells.

[0026] As an optional technical solution of an embodiment of the present application, the first groove side surface and the second groove side surface are both inclined, and the distance between the first groove side surface and the second groove side surface gradually decreases from the direction of the groove opening to the bottom surface of the first groove; the third groove side surface and the fourth groove side surface are both inclined, and the distance between the third groove side surface and the fourth groove side surface gradually decreases from the direction of the groove opening to the bottom surface of the first groove; the angle between the first groove side surface and the second groove side surface is a, and the angle between the third groove side surface and the fourth groove side surface is b, a>b or a<b.

[0027] In the above technical solution, by making the first groove side and the second groove side both inclined, and making the third groove side and the fourth groove side both inclined, and a>b or a<b, it is beneficial to flow the material when stamping the first groove and reduce stress concentration.

[0028] As an optional technical solution of an embodiment of the present application, the pressure relief mechanism is provided with a second groove, the first groove and the second groove are arranged along the thickness direction of the wall portion, the second groove has a second groove bottom surface, and the notch of the first groove is formed on the second groove bottom surface.

[0029] In the above technical solution, the notch of the first groove is formed on the bottom surface of the first groove of the second groove. During stamping, the second groove can be stamped first and then the first groove is stamped, thereby reducing the forming force on the pressure relief mechanism, reducing the risk of cracks in the pressure relief mechanism, and improving the reliability of the battery cell.

[0030] As an optional technical solution of an embodiment of the present application, the pressure relief mechanism has a first surface and a second surface arranged opposite to each other in the thickness direction of the wall portion, and the second groove includes a multi-level groove arranged in sequence along the direction from the first surface to the second surface. In the two adjacent levels of the grooves, the first-level groove away from the first surface is arranged at the groove bottom surface of the first-level groove close to the first surface; the groove bottom surface of the first-level groove farthest from the first surface among the multi-level grooves is the second groove bottom surface.

[0031] In the above technical solution, the second groove comprises a multi-level groove. During stamping, the multi-level grooves can be stamped out step by step, thereby reducing the forming force on the pressure relief mechanism, reducing the risk of cracks in the pressure relief mechanism, and improving the reliability of the battery cell. Furthermore, the first groove is stamped in the last step, without any subsequent stamping steps. This helps maintain the shape of the first groove, ensuring consistent burst pressure across multiple battery cells during manufacturing, and thus improving battery cell reliability.

[0032] As an optional technical solution of an embodiment of the present application, the pressure relief mechanism is separately provided from the wall portion, the wall portion is provided with a pressure relief hole, and the pressure relief mechanism is installed on the wall portion and covers the pressure relief hole.

[0033] In the above technical solution, the pressure relief mechanism is separated from the wall portion and installed on the wall portion, so as to facilitate processing and manufacturing.

[0034] As an optional technical solution of an embodiment of the present application, the base material of the wall portion is iron, and the pressure relief mechanism is welded to the wall portion.

[0035] In the above technical solution, the base materials of the pressure relief mechanism and the wall are both iron, which makes it easier to weld the pressure relief mechanism and the wall, thereby reducing the phenomenon of welding cracks between the pressure relief mechanism and the wall, thereby reducing the risk of leakage of the battery cell and improving the reliability of the battery cell.

[0036] As an optional technical solution of the embodiment of the present application, the pressure relief mechanism is integrally formed with the wall portion.

[0037] In the above technical solution, the pressure relief mechanism is integrally formed with the wall, eliminating the need for additional welding or bonding processes, which helps reduce the risk of leakage from the pressure relief mechanism. Furthermore, during production, it is easier to ensure that the detonation pressure of multiple processed battery cells is relatively consistent.

[0038] As an optional technical solution of the embodiment of the present application, the material of the pressure relief mechanism is 304 stainless steel, 305 stainless steel or 316 stainless steel.

[0039] In the above technical solution, 304 stainless steel, 305 stainless steel and 316 stainless steel have the advantages of corrosion resistance, high temperature resistance and good processing performance. The pressure relief mechanism manufactured with 304 stainless steel, 305 stainless steel or 316 stainless steel has high strength, which can reduce the risk of deformation of the pressure relief mechanism due to force, which is beneficial to reducing the risk of premature valve opening and pressure relief of the pressure relief mechanism, which is beneficial to improving the service life and reliability of the battery cell and improving the consistency of the detonation pressure of multiple battery cells.

[0040] In a second aspect, an embodiment of the present application further provides a battery device, which includes the above-mentioned battery cell.

[0041] In a third aspect, an embodiment of the present application further provides an electric device, which includes the above-mentioned battery cell, and the battery cell is used to provide electric energy for the electric device. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0044] Figure 2 An exploded view of a battery device provided in some embodiments of the present application;

[0045] Figure 3 A schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0046] Figure 4 An exploded view of a battery cell provided in some embodiments of the present application;

[0047] Figure 5 A schematic top view of a pressure relief mechanism provided in some embodiments of the present application;

[0048] Figure 6 for Figure 5 Cross-sectional view at the AA position;

[0049] Figure 7 for Figure 6 A magnified view of position B in the middle;

[0050] Figure 8 A partial cross-sectional view of a pressure relief mechanism provided in some other embodiments of the present application;

[0051] Figure 9 A partial cross-sectional view of a pressure relief mechanism provided in some other embodiments of the present application;

[0052] Figure 10 A partial cross-sectional view of a pressure relief mechanism provided in some further embodiments of the present application;

[0053] Figure 11 A partial cross-sectional view of a pressure relief mechanism provided in some embodiments of the present application;

[0054] Figure 12 A partial cross-sectional view of a pressure relief mechanism provided in some other embodiments of the present application;

[0055] Figure 13 Cross-sectional views of pressure relief mechanisms provided in some further embodiments of the present application.

[0056] Icons: 10-box; 11-first box body; 12-second box body; 20-battery cell; 21-shell; 211-shell; 212-end cover; 213-wall; 2131-pressure relief hole; 23-electrode assembly; 231-main body; 232-ear; 24-pressure relief mechanism; 241-first groove; 2411-first groove bottom; 2412-notch; 2413-first groove side; 2414-second groove side; 2415-third groove side; 2416-fourth groove side; 242-second groove; 2421-first level groove; 2422-second level groove; 24221-second groove bottom; 243-first surface; 244-second surface; 25-electrode terminal; 26-protective member; 27-insulating member; 100-battery device; 200-controller; 300-motor; 1000-vehicle. DETAILED DESCRIPTION

[0057] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0058] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0059] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0060] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0061] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0062] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0063] The term "plurality" used in this application refers to two or more (including two).

[0064] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0065] Battery cells include but are not limited to lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0066] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process, active ions (such as lithium ions) move back and forth between the positive and negative electrodes. A separator, placed between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0067] 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.

[0068] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0069] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a surface silver plating treatment, stainless steel with a surface silver plating treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0070] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include but are not limited to at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include but are not limited to lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3Mn 1 / 3 O2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05O2) and at least one of its modified compounds, etc.

[0071] In some embodiments, a positive electrode may utilize a metal foam. The metal foam may include nickel foam, copper foam, aluminum foam, alloy foam, or the like. When a metal foam is used as the positive electrode, the surface of the metal foam may or may not include a positive electrode active material. For example, a lithium source material, potassium metal, or sodium metal may be filled or / and deposited within the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

[0072] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0073] As an example, the negative electrode current collector can be a metal foil, a metal foam, or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium can be used. The metal foam can be nickel foam, copper foam, aluminum foam, alloy foam, etc. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0074] 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.

[0075] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0076] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells that is well known in the art. 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, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional 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.

[0077] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0078] In some embodiments, the separator is a separator membrane, which can be any known porous separator membrane with good chemical and mechanical stability.

[0079] As an example, the separator can be made of at least one of fiberglass, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film. In the case of a multi-layer composite film, the materials of each layer can be the same or different. The separator can be a separate component positioned between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0080] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel, or solid. Liquid electrolytes include an electrolyte salt and a solvent.

[0081] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium bisoxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0082] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent 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, methyltetrahydrofuran, diphenyl ether and crown ether.

[0083] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0084] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0085] In some embodiments, the electrode assembly is a laminate structure.

[0086] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0087] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0088] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0089] As an example, a plurality of separators may be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0090] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0091] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0092] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0093] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0094] In some embodiments, the housing can be a sealed structure or a non-sealed structure. For example, when the housing is a sealed structure, the housing can protect the electrode assembly and, to a certain extent, prevent leakage of the electrolyte. When the housing is a non-sealed structure, the housing can also protect the electrode assembly. A sealing bag can be included between the housing and the electrode assembly to encapsulate the electrode assembly and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum-plastic film.

[0095] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. Prismatic battery cells include square-shell battery cells, blade-shaped battery cells, and polygonal battery cells. Polygonal battery cells are, for example, hexagonal battery cells.

[0096] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, parallel, or hybrid via a busbar.

[0097] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells. As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module.

[0098] As an example, a battery module may be formed by bundling a plurality of battery cells by cable ties.

[0099] In some embodiments, the battery device may be a battery pack, which may include a case and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case.

[0100] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0101] As an example, the battery cell assembly may also be housed in the box by directly fixing the plurality of battery cells to the box.

[0102] As an example, the housing may include a first housing body and a second housing body. The first and second housing bodies engage to form an enclosed space within the housing to house the battery cell assembly. Enclosed here means covered or closed, and can be either sealed or unsealed. The first housing body may be a top cover or a bottom plate.

[0103] As an example, the box body may include a top cover, a frame, and a bottom plate, wherein the top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body to accommodate the battery cell assembly.

[0104] As an example, the box body can be used as a part of the chassis structure of the vehicle. For example, the top cover of the box body can become at least a part of the floor of the vehicle, or the frame of the box body can become at least a part of the crossbeam and longitudinal beam of the vehicle.

[0105] In some embodiments, the battery device refers to an energy storage device, which includes a box with a door on at least one side. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0106] Currently, market developments indicate that batteries are increasingly being used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As battery applications continue to expand, market demand is also growing.

[0107] Batteries are widely used in new energy applications, such as electric vehicles and new energy vehicles. These have become a new trend in the automotive industry. The development of battery technology requires consideration of multiple design factors, including performance parameters such as energy density, discharge capacity, and charge / discharge rate. Furthermore, battery reliability must be considered. However, current battery reliability is relatively poor.

[0108] For battery cells, in order to improve the reliability of battery cells, the existing technology is to set a pressure relief mechanism on the end cover of the battery cell. The pressure relief mechanism is provided with a notched groove. When the internal pressure of the battery cell reaches the bursting pressure, the notched groove cracks to release the pressure inside the battery cell, thereby reducing the risk of battery cell explosion and fire.

[0109] The pressure relief mechanism in the existing technology is generally made of aluminum. The strength of the aluminum pressure relief mechanism is relatively low, and the weak part is easy to crack prematurely due to the pressure change inside the battery cell or the external impact. That is, before the internal pressure of the battery cell reaches the desired bursting pressure of the project, the weak part has already cracked, causing the battery cell to be scrapped prematurely and the reliability of the battery cell to be poor.

[0110] If only higher-strength materials are used to manufacture the pressure relief mechanism, due to the higher strength of the material, it will be difficult to flow the material when stamping the notched grooves, which can easily lead to stress concentration. As a result, the bursting pressures of multiple battery cells will vary greatly when manufacturing multiple battery cells. Some battery cells will have cracked at weak parts before the internal pressure reaches the bursting pressure, while some battery cells will still not crack at weak parts after the internal pressure exceeds the bursting pressure, which increases the risk of battery cell explosion and fire, resulting in poor reliability of the battery cells.

[0111] In view of this, an embodiment of the present application provides a battery cell, which includes a shell and a pressure relief mechanism, wherein the shell has a wall portion, and the pressure relief mechanism is arranged on the wall portion. The base material of the pressure relief mechanism is iron. The pressure relief mechanism is provided with a first groove, and the pressure relief mechanism is configured to break along at least part of the first groove when the pressure inside the shell reaches a threshold value to release pressure. The first groove has a first groove bottom surface, which is an arc surface that is concave in a direction away from the notch of the first groove, and the arc surface is arc-shaped in the cross section of the first groove. The cross section is perpendicular to the extension direction of the first groove.

[0112] The pressure relief mechanism's base material is iron, which effectively enhances its structural strength and reduces the risk of premature valve opening, thereby improving the lifespan and reliability of the battery cells. By configuring the bottom surface of the first groove as a curved surface that is concave away from the notch of the first groove, material flow is facilitated during stamping and forming the first groove, alleviating stress concentration and ensuring consistent burst pressure across multiple battery cells during manufacturing, thereby improving battery cell reliability.

[0113] The technical solutions described in the embodiments of the present application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0114] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0115] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application. A battery device 100 is disposed within vehicle 1000. Battery device 100 can be located at the bottom, front, or rear of vehicle 1000. Battery device 100 can be used to power vehicle 1000. For example, battery device 100 can serve as the operating power source of vehicle 1000.

[0116] The vehicle 1000 may further include a controller 200 and a motor 300 . The controller 200 is used to control the battery device 100 to supply power to the motor 300 , for example, to meet the power requirements of the vehicle 1000 during startup, navigation, and driving.

[0117] In some embodiments of the present application, the battery device 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0118] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of the present application. The battery device 100 may include a housing 10 and a battery cell 20 , wherein the housing 10 is used to accommodate the battery cell 20 .

[0119] Among them, a closed space for accommodating the battery cells 20 is formed inside the box body 10. The box body 10 can adopt a variety of structures. In some embodiments, the box body 10 may include a first box body 11 and a second box body 12, and the first box body 11 and the second box body 12 are buckled with each other. The first box body 11 and the second box body 12 can be in various shapes, such as a rectangular parallelepiped, a cylinder, etc. The first box body 11 can be a hollow structure with one side open, and the second box body 12 can also be a hollow structure with one side open. The open side of the second box body 12 is buckled with the open side of the first box body 11 to form a box body 10 with a closed space. The first box body 11 can also be a hollow structure with one side open, and the second box body 12 can be a plate-like structure. The second box body 12 is buckled with the open side of the first box body 11 to form a box body 10 with an accommodating space.

[0120] In the battery device 100, there can be one or more battery cells 20. If there are multiple battery cells 20, the multiple battery cells 20 can be connected in series, parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. Multiple battery cells 20 can be connected in series, parallel, or in a hybrid connection to form a battery module, which is then connected in series, parallel, or in a hybrid connection to form a single unit and housed within the housing 10. Alternatively, all battery cells 20 can be directly connected in series, parallel, or in a hybrid connection, and then the entire unit formed by all battery cells 20 is housed within the housing 10.

[0121] In some embodiments, the battery device 100 may further include a busbar component, through which the multiple battery cells 20 can be electrically connected to each other, thereby enabling series connection, parallel connection, or hybrid connection of the multiple battery cells 20. The busbar component may be a metal conductor, such as copper, iron, aluminum, stainless steel, or aluminum alloy.

[0122] Please refer to Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 and Figure 7 , Figure 3 This is a schematic structural diagram of a battery cell 20 provided in some embodiments of the present application. Figure 4 An exploded view of a battery cell 20 provided in some embodiments of the present application. Figure 5 Schematic top view of the pressure relief mechanism 24 provided in some embodiments of the present application. Figure 6 for Figure 5 Cross-sectional view at position AA. Figure 7 for Figure 6 An enlarged view of position B in the middle. An embodiment of the present application provides a battery cell 20, which includes a shell 21 and a pressure relief mechanism 24, the shell 21 having a wall portion 213, and the pressure relief mechanism 24 is arranged on the wall portion 213. The base material of the pressure relief mechanism 24 is iron. The pressure relief mechanism 24 is provided with a first groove 241, and the pressure relief mechanism 24 is configured to crack along at least part of the first groove 241 when the pressure inside the shell 21 reaches a threshold value to release pressure. The first groove 241 has a first groove bottom surface 2411, and the first groove bottom surface 2411 is an arc surface that is concave in the direction of the notch 2412 away from the first groove 241, and the arc surface is arc-shaped in the cross section of the first groove 241. The cross section is perpendicular to the extension direction of the first groove 241.

[0123] The battery cell 20 refers to the smallest unit constituting the battery device 100 .

[0124] The housing 21 includes a shell 211 and an end cap 212. The shell 211 has an accommodation space with one end open, and the accommodation space is used to accommodate the electrode assembly 23. The end cap 212 is connected to the shell 211 and closes the opening.

[0125] The end cap 212 refers to a component that covers the opening of the shell 211 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 212 can be adapted to the shape of the shell 211 to match the shell 211. Optionally, the end cap 212 can be made of a material with a certain hardness and strength (such as an aluminum alloy). In this way, the end cap 212 is not easily deformed when squeezed or collided, so that the battery cell 20 can have a higher structural strength and improved reliability. The material of the end cap 212 can include but is not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. The end cap 212 is also provided with an electrode terminal 25, which is used to electrically connect to the tab 232 of the electrode assembly 23 to input or output electrical energy of the battery cell 20. The electrode terminal 25 and the tab 232 can be directly connected, for example, the electrode terminal 25 and the tab 232 are directly welded. The electrode terminal 25 and the tab 232 can also be indirectly connected, for example, through a current collecting member. The battery cell 20 also includes an insulator 27, which is disposed inside the end cap 212. The insulator 27 can be used to isolate the electrical connection components within the housing 211 from the end cap 212 to reduce the risk of short circuits. Exemplarily, the insulator 27 can be made of plastic, rubber, or the like.

[0126] The housing 211 is a component that cooperates with the end cap 212 to form the internal environment of the battery cell 20. This internal environment can be used to accommodate the electrode assembly 23, electrolyte, and other components. The housing 211 and end cap 212 can be separate components. An opening can be provided in the housing 211, and the end cap 212 is placed over the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 212 and housing 211 can be integrated. Specifically, the end cap 212 and housing 211 can form a common joint surface before other components are inserted into the housing. When the interior of the housing 211 needs to be enclosed, the end cap 212 is placed over the housing 211. The housing 211 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the housing 211 can be determined based on the specific shape and size of the electrode assembly 23. The material of the housing 211 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0127] The electrode assembly 23 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 23 may be contained in the housing 211. The electrode assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active materials constitute the main body 231 of the electrode assembly 23, and the portions of the positive and negative electrode sheets without active materials each constitute a tab 232. The positive tab and the negative tab may be located together at one end of the main body 231 or respectively at both ends of the main body 231. During the charge and discharge process of the battery cell 20, the positive electrode active material and the negative electrode active material react with the electrolyte.

[0128] The wall portion 213 may be the end cover 212 of the housing 21 or a wall of the shell 211 of the housing 21. Figure 3 and Figure 4 In the embodiment, the wall portion 213 is the end cap 212. In other embodiments, the wall portion 213 is the bottom wall of the housing 211 opposite to the end cap 212. In still other embodiments, the wall portion 213 may also be a side wall of the housing 211 adjacent to and connected to the end cap 212.

[0129] The pressure relief mechanism 24 is a component designed to release the internal pressure of the battery cell 20 when the internal pressure or temperature reaches the burst pressure. The pressure relief mechanism 24 is mounted on the wall portion 213. The pressure relief mechanism 24 is separate from and connected to the wall portion 213. During manufacturing, a pressure relief hole 2131 is formed in the wall portion 213. The pressure relief mechanism 24 and the wall portion 213 are provided separately and then connected together so that the pressure relief mechanism 24 covers the pressure relief hole 2131. For example, the pressure relief mechanism 24 can be welded to the wall portion 213. The pressure relief mechanism 24 can be a burst disk mounted on the wall portion 213. The location of the pressure relief mechanism 24 can be used to identify which wall of the housing 21 is the wall portion 213. For example, if the pressure relief mechanism 24 is mounted on the end cap 212, the end cap 212 is the wall portion 213. If the pressure relief mechanism 24 is mounted on the bottom wall of the housing 211, the bottom wall is the wall portion 213. When the pressure relief mechanism 24 is disposed on a side wall of the housing 211 , the side wall serves as the wall portion 213 .

[0130] "The base material of the pressure relief mechanism 24 is iron" means that the material of the pressure relief mechanism 24 has the largest mass percentage of iron. For example, the pressure relief mechanism 24 can be made of carbon steel or stainless steel. The carbon steel can be low carbon steel, medium carbon steel, or high carbon steel.

[0131] The first groove 241 is a pressure relief groove provided in the pressure relief mechanism 24. When the pressure inside the battery cell 20 reaches the burst pressure of the pressure relief mechanism 24, the pressure relief mechanism 24 can rupture along at least a portion of the first groove 241 to release the pressure. It is understood that when the pressure of the battery cell 20 is released, the pressure relief mechanism 24 can rupture along all or a portion of the first groove 241. The first groove 241 can be an annular groove, for example, the first groove 241 can be in the shape of a circular ring or an elliptical ring. The first groove 241 can also be a non-annular groove, for example, the first groove 241 can be a C-shaped groove, a U-shaped groove, etc.

[0132] Please refer to Figure 7 , the thickness direction of the wall portion 213 is the Z direction shown in the figure.

[0133] The first groove bottom surface 2411 is the bottom surface of the first groove 241. Along the thickness direction of the wall portion 213, the first groove bottom surface 2411 is the surface of the first groove 241 farthest from the notch 2412 of the first groove 241. The first groove bottom surface 2411 is an arcuate surface and is concave in a direction away from the notch 2412 of the first groove 241.

[0134] The first groove 241 may include at least one groove segment. The first groove bottom surface 2411 corresponding to the groove segment may be arc-shaped in cross-section, with the cross-section being perpendicular to the extension direction of the groove segment. For example, the groove segment may be a linear groove extending along a straight line, in which case the cross-section is perpendicular to the straight line. Alternatively, the groove segment may be an arc groove extending along a circular arc, in which case the cross-section is perpendicular to the circular arc.

[0135] In some embodiments, the arc shape may be a circular arc, in other embodiments, the arc shape may be an elliptical arc, and in still other embodiments, the arc shape may be a parabolic arc.

[0136] The base material of the pressure relief mechanism 24 is iron, which effectively enhances the structural strength of the pressure relief mechanism 24 and reduces the risk of premature valve opening and pressure relief by the pressure relief mechanism 24, thereby improving the service life and reliability of the battery cells 20. By configuring the first groove bottom surface 2411 of the first groove 241 as a curved surface that is concave in a direction away from the notch 2412 of the first groove 241, material flow is facilitated during the stamping and forming of the first groove 241, thereby alleviating stress concentration and ensuring consistent burst pressure across multiple battery cells 20 during manufacture, thereby improving the reliability of the battery cells 20.

[0137] Please refer to Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 and Figure 7 In some embodiments, the arc surface is a circular arc surface.

[0138] When the arc surface is a circular arc surface, the arc surface is in an arc shape in the cross section of the first groove 241 .

[0139] By setting the first groove bottom surface 2411 of the first groove 241 to be an arc surface that is concave in the direction of the groove opening 2412 away from the first groove 241, it is easier to flow the material when stamping the first groove 241, which is more conducive to alleviating stress concentration, and is more conducive to keeping the bursting pressure of multiple battery cells 20 consistent when manufacturing multiple battery cells 20, which is more conducive to improving the reliability of the battery cells 20.

[0140] Please refer to Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 and Figure 7 In some embodiments, the arc surface defines a notch 2412 of the first groove 241 .

[0141] The arc surface defines a notch 2412 of the first groove 241 , and the cross section of the first groove 241 is arc-shaped as a whole.

[0142] By making the cross section of the first groove 241 as a whole arc-shaped, it is convenient for material flow when the first groove 241 is stamped and formed, which is beneficial to relieve stress concentration, and is beneficial to maintaining the same bursting pressure of multiple battery cells 20 when manufacturing multiple battery cells 20, which is beneficial to improving the reliability of the battery cells 20.

[0143] Please refer to Figure 8 , Figure 8 This is a partial cross-sectional view of a pressure relief mechanism 24 provided in some other embodiments of the present application. In some other embodiments, the first groove 241 includes a first groove side surface 2413 and a second groove side surface 2414. The first groove side surface 2413 and the second groove side surface 2414 are arranged opposite each other along the width direction of the first groove 241. The first groove bottom surface 2411 connects the first groove side surface 2413 and the second groove side surface 2414.

[0144] Please refer to Figure 8 , the width direction of the first groove 241 is the X direction shown in the figure.

[0145] The first groove side surface 2413 and the second groove side surface 2414 are both flat. The first groove side surface 2413 is connected to one end of the first groove bottom surface 2411, and the second groove side surface 2414 is connected to the other end of the first groove bottom surface 2411. The first groove side surface 2413 is arranged opposite to the second groove side surface 2414 along the width direction of the first groove 241.

[0146] The first groove bottom surface 2411 connects the first groove side surface 2413 and the second groove side surface 2414. The first groove side surface 2413 and the second groove side surface 2414 are flat surfaces, and the first groove bottom surface 2411 is an arc surface. This makes it convenient to keep the width of the first groove 241 small when the depth of the first groove 241 is large, so as to facilitate controlling the bursting pressure of the pressure relief mechanism 24.

[0147] Please refer to Figure 8 In some embodiments, the first groove side surface 2413 and the second groove side surface 2414 define a notch 2412 of the first groove 241 .

[0148] One end of the first groove side surface 2413 is connected to one end of the first groove bottom surface 2411, one end of the second groove side surface 2414 is connected to the other end of the first groove bottom surface 2411, and the other end of the first groove side surface 2413 and the other end of the second groove side surface 2414 jointly define the groove opening 2412 of the first groove 241.

[0149] The first groove side surface 2413 and the second groove side surface 2414 define the groove opening 2412 of the first groove 241, so that the cross-sectional shape of the first groove 241 is relatively simple, which is beneficial to reducing the stress between the groove side surface and the first groove bottom surface 2411, alleviating stress concentration, and is beneficial to keeping the bursting pressure of multiple battery cells 20 consistent when manufacturing multiple battery cells 20, which is beneficial to improving the reliability of the battery cells 20.

[0150] Please refer to Figure 8 In some embodiments, the first groove side surface 2413 and the second groove side surface 2414 are both inclined, and the distance between the first groove side surface 2413 and the second groove side surface 2414 gradually decreases from the groove opening 2412 to the first groove bottom surface 2411.

[0151] The first groove side surface 2413 and the second groove side surface 2414 are both inclined. The inclination degree of the first groove side surface 2413 and the second groove side surface 2414 can be the same, or the inclination degree of the first groove side surface 2413 and the second groove side surface 2414 can be different. Figure 8 ,exist Figure 8 In the illustrated embodiment, the first groove side surface 2413 and the second groove side surface 2414 have the same degree of inclination.

[0152] In the projection plane perpendicular to the thickness direction of the wall portion 213 , the orthographic projection of the first groove side surface 2413 and the orthographic projection of the first groove bottom surface 2411 do not overlap, and the orthographic projection of the second groove side surface 2414 and the orthographic projection of the first groove bottom surface 2411 do not overlap.

[0153] By tilting the first groove side 2413 and the second groove side 2414 , the distance between the first groove side 2413 and the second groove side 2414 gradually decreases from the groove opening 2412 to the first groove bottom 2411 , which is beneficial to material flow during stamping of the first groove 241 and reduces stress concentration.

[0154] Please refer to Figure 9 , Figure 9 This is a partial cross-sectional view of the pressure relief mechanism 24 provided in some other embodiments of the present application. In some other embodiments, the first groove side surface 2413 is parallel to the second groove side surface 2414.

[0155] The first groove side surface 2413 is parallel to the thickness direction of the wall portion 213 , and the second groove side surface 2414 is also parallel to the thickness direction of the wall portion 213 .

[0156] When the first groove side surface 2413 and the second groove side surface 2414 are parallel, the width of the first groove 241 is easier to control, which is beneficial for maintaining the same bursting pressure of multiple battery cells 20 when manufacturing multiple battery cells 20 and improving the reliability of the battery cells 20.

[0157] Please refer to Figure 10 , Figure 10 This is a partial cross-sectional view of a pressure relief mechanism 24 provided in some further embodiments of the present application. In some further embodiments, the first groove 241 further includes a third groove side surface 2415 and a fourth groove side surface 2416, which are disposed opposite each other along the width direction of the first groove 241. The first groove side surface 2413 connects one end of the first groove bottom surface 2411 and the third groove side surface 2415, and the second groove side surface 2414 connects the other end of the first groove bottom surface 2411 and the fourth groove side surface 2416.

[0158] The third groove side surface 2415 and the fourth groove side surface 2416 are both flat. The third groove side surface 2415 is connected to the end of the first groove side surface 2413 away from the first groove bottom surface 2411, and the fourth groove side surface 2416 is connected to the end of the second groove side surface 2414 away from the first groove bottom surface 2411. The third groove side surface 2415 is arranged opposite to the fourth groove side surface 2416 along the width direction of the first groove 241.

[0159] By providing the third groove side surface 2415 and the fourth groove side surface 2416 , it is convenient to keep the width of the first groove 241 small when the depth of the first groove 241 is large, so as to facilitate controlling the bursting pressure of the pressure relief mechanism 24 .

[0160] Please refer to Figure 10 In some embodiments, the third groove side surface 2415 and the fourth groove side surface 2416 define the notch 2412 of the first groove 241 .

[0161] One end of the third groove side 2415 is connected to one end of the first groove side 2413 away from the first groove bottom surface 2411, one end of the fourth groove side 2416 is connected to one end of the second groove side 2414 away from the first groove bottom surface 2411, and the other end of the third groove side 2415 and the other end of the fourth groove side 2416 jointly define the groove opening 2412 of the first groove 241.

[0162] The third groove side surface 2415 and the fourth groove side surface 2416 define the groove opening 2412 of the first groove 241, so that the cross-sectional shape of the first groove 241 is relatively simple, which is beneficial to reducing the stress between two adjacent groove side surfaces and between the groove side surfaces and the first groove bottom surface 2411, alleviating stress concentration, and is beneficial to keeping the bursting pressure of multiple battery cells 20 consistent when manufacturing multiple battery cells 20, thereby improving the reliability of the battery cells 20.

[0163] Please refer to Figure 10 In some embodiments, the first groove side surface 2413 is parallel to the second groove side surface 2414. The third groove side surface 2415 and the fourth groove side surface 2416 are both inclined, and the distance between the third groove side surface 2415 and the fourth groove side surface 2416 gradually decreases from the groove opening 2412 to the first groove bottom surface 2411.

[0164] The first groove side surface 2413 is parallel to the thickness direction of the wall portion 213 , and the second groove side surface 2414 is also parallel to the thickness direction of the wall portion 213 .

[0165] The third groove side surface 2415 and the fourth groove side surface 2416 are both inclined. The inclination degree of the third groove side surface 2415 and the fourth groove side surface 2416 can be the same, or the inclination degree of the third groove side surface 2415 and the fourth groove side surface 2416 can be different. Figure 10 ,exist Figure 10 In the illustrated embodiment, the third groove side 2415 and the fourth groove side 2416 have the same degree of inclination.

[0166] In the projection plane perpendicular to the thickness direction of the wall portion 213 , the orthographic projection of the third groove side surface 2415 and the orthographic projection of the first groove bottom surface 2411 do not overlap, and the orthographic projection of the fourth groove side surface 2416 and the orthographic projection of the first groove bottom surface 2411 do not overlap.

[0167] By making the first groove side surface 2413 parallel to the second groove side surface 2414, the third groove side surface 2415 and the fourth groove side surface 2416 are both inclined, and the distance between the third groove side surface 2415 and the fourth groove side surface 2416 gradually decreases from the groove opening 2412 to the first groove bottom surface 2411, which is beneficial to the flow of material when stamping the first groove 241 and reducing stress concentration.

[0168] Please refer to Figure 11 , Figure 11 This is a partial cross-sectional view of a pressure relief mechanism 24 provided in some other embodiments of the present application. In some other embodiments, the first groove side surface 2413 and the second groove side surface 2414 are both inclined, and along the thickness direction of the wall portion 213, the distance between the first groove side surface 2413 and the second groove side surface 2414 gradually decreases from the groove opening 2412 toward the first groove bottom surface 2411. The third groove side surface 2415 is parallel to the fourth groove side surface 2416.

[0169] The first groove side surface 2413 and the second groove side surface 2414 are both inclined. The inclination degree of the first groove side surface 2413 and the second groove side surface 2414 can be the same, or the inclination degree of the first groove side surface 2413 and the second groove side surface 2414 can be different. Figure 11 ,exist Figure 11 In the illustrated embodiment, the first groove side surface 2413 and the second groove side surface 2414 have the same degree of inclination. In a projection plane perpendicular to the thickness direction of the wall portion 213, the orthographic projection of the first groove side surface 2413 and the orthographic projection of the first groove bottom surface 2411 do not overlap, and the orthographic projection of the second groove side surface 2414 and the orthographic projection of the first groove bottom surface 2411 do not overlap.

[0170] The third groove side surface 2415 is parallel to the thickness direction of the wall portion 213 , and the fourth groove side surface 2416 is also parallel to the thickness direction of the wall portion 213 .

[0171] By making the first groove side surface 2413 and the second groove side surface 2414 both inclined, along the thickness direction of the wall portion 213, the distance between the first groove side surface 2413 and the second groove side surface 2414 gradually decreases from the groove opening 2412 to the first groove bottom surface 2411, and the third groove side surface 2415 is parallel to the fourth groove side surface 2416, so that the width of the first groove 241 is easier to control, which is beneficial to keep the bursting pressure of multiple battery cells 20 consistent when manufacturing multiple battery cells 20, and is beneficial to improving the reliability of the battery cells 20.

[0172] Please refer to Figure 12 , Figure 12A partial cross-sectional view of a pressure relief mechanism 24 provided in yet other embodiments of the present application. In yet other embodiments, the first groove side surface 2413 and the second groove side surface 2414 are both inclined, and the distance between the first groove side surface 2413 and the second groove side surface 2414 gradually decreases from the groove opening 2412 toward the first groove bottom surface 2411. The third groove side surface 2415 and the fourth groove side surface 2416 are both inclined, and the distance between the third groove side surface 2415 and the fourth groove side surface 2416 gradually decreases from the groove opening 2412 toward the first groove bottom surface 2411. The angle between the first groove side surface 2413 and the second groove side surface 2414 is a, and the angle between the third groove side surface 2415 and the fourth groove side surface 2416 is b, where a>b or a<b.

[0173] The first groove side surface 2413 and the second groove side surface 2414 are both inclined. The inclination degree of the first groove side surface 2413 and the second groove side surface 2414 can be the same, or the inclination degree of the first groove side surface 2413 and the second groove side surface 2414 can be different. Figure 12 ,exist Figure 12 In the illustrated embodiment, the first groove side surface 2413 and the second groove side surface 2414 have the same degree of inclination. In a projection plane perpendicular to the thickness direction of the wall portion 213, the orthographic projection of the first groove side surface 2413 and the orthographic projection of the first groove bottom surface 2411 do not overlap, and the orthographic projection of the second groove side surface 2414 and the orthographic projection of the first groove bottom surface 2411 do not overlap.

[0174] The third groove side surface 2415 and the fourth groove side surface 2416 are both inclined. The inclination degree of the third groove side surface 2415 and the fourth groove side surface 2416 can be the same, or the inclination degree of the third groove side surface 2415 and the fourth groove side surface 2416 can be different. Figure 12 ,exist Figure 12 In the illustrated embodiment, the third groove side surface 2415 and the fourth groove side surface 2416 have the same degree of inclination. In a projection plane perpendicular to the thickness direction of the wall portion 213, the orthographic projection of the third groove side surface 2415 and the orthographic projection of the first groove bottom surface 2411 do not overlap, and the orthographic projection of the fourth groove side surface 2416 and the orthographic projection of the first groove bottom surface 2411 do not overlap.

[0175] a is the angle between the first groove side surface 2413 and the second groove side surface 2414. b is the angle between the third groove side surface 2415 and the fourth groove side surface 2416. a≠b, meaning the angle between the first groove side surface 2413 and the second groove side surface 2414 is not equal to the angle between the third groove side surface 2415 and the fourth groove side surface 2416.

[0176] Please refer to Figure 12 ,exist Figure 12In the illustrated embodiment, b>a, that is, the angle between the third groove side surface 2415 and the fourth groove side surface 2416 is greater than the angle between the first groove side surface 2413 and the second groove side surface 2414 .

[0177] In other embodiments, b<a, that is, the angle between the third groove side surface 2415 and the fourth groove side surface 2416 is smaller than the angle between the first groove side surface 2413 and the second groove side surface 2414 .

[0178] By making the first groove side surface 2413 and the second groove side surface 2414 both inclined, and making the third groove side surface 2415 and the fourth groove side surface 2416 both inclined, and a>b or a<b, it is beneficial to flow the material when stamping the first groove 241 and reduce stress concentration.

[0179] Please refer to Figure 5 and Figure 6 In some embodiments, the pressure relief mechanism 24 is provided with a second groove 242 , and the first groove 241 and the second groove 242 are arranged along the thickness direction of the wall portion 213 . The second groove 242 has a second groove bottom surface 24221 , and the notch 2412 of the first groove 241 is formed on the second groove bottom surface 24221 .

[0180] The pressure relief mechanism 24 includes a first surface 243 , wherein the second groove 242 is disposed on the first surface 243 , and the first groove 241 is disposed on the second groove bottom surface 24221 of the second groove 242 .

[0181] The notch 2412 of the first groove 241 is formed on the first groove bottom surface 2411 of the second groove 242. During stamping, the second groove 242 can be stamped first, and then the first groove 241 can be stamped, thereby reducing the forming force on the pressure relief mechanism 24, reducing the risk of cracks in the pressure relief mechanism 24, and improving the reliability of the battery cell 20.

[0182] Please refer to Figure 13 , Figure 13 This is a cross-sectional view of a pressure relief mechanism 24 provided in yet other embodiments of the present application. In yet other embodiments, the pressure relief mechanism 24 has a first surface 243 and a second surface 244 disposed opposite each other in the thickness direction of the wall portion 213. The second groove 242 includes multiple stages of grooves sequentially arranged from the first surface 243 to the second surface 244. In two adjacent stages of grooves, the first stage groove farther from the first surface 243 is disposed at the bottom surface of the first stage groove closer to the first surface 243. The bottom surface of the first stage groove furthest from the first surface 243 in the multiple stages of grooves is the second groove bottom surface 24221.

[0183] The pressure relief mechanism 24 includes a first surface 243 and a second surface 244. The first surface 243 and the second surface 244 are arranged opposite to each other along the thickness direction of the wall portion 213. The second groove 242 includes a multi-stage groove. The multi-stage groove is arranged in sequence on the pressure relief mechanism 24 along the direction from the first surface 243 to the second surface 244. The contour of the bottom surface of the multi-stage groove decreases step by step.

[0184] The bottom surface of the first groove farthest from the first surface 243 in the multi-stage grooves is the second groove bottom surface 24221 , that is, the first groove 241 is disposed on the bottom surface of the first groove farthest from the first surface 243 in the multi-stage grooves.

[0185] For example, Figure 13 As shown, the second groove 242 includes two levels of grooves, namely a first-level groove 2421 and a second-level groove 2422. During processing and forming, the first-level groove 2421 can be first stamped on the first surface 243, and then the second-level groove 2422 can be stamped on the bottom surface of the first-level groove 2421. Finally, the first groove 241 can be stamped on the bottom surface of the second-level groove 2422.

[0186] The second groove 242 comprises multiple levels of grooves. During the stamping process, the multiple levels of grooves can be stamped out step by step, thereby reducing the forming force on the pressure relief mechanism 24 and the risk of cracks in the pressure relief mechanism 24, thereby improving the reliability of the battery cell 20. Furthermore, the first groove 241 is stamped out in the last step, with no subsequent stamping steps. This helps maintain the shape of the first groove 241, ensuring consistent burst pressure across multiple battery cells 20 during manufacture, thereby improving the reliability of the battery cells 20.

[0187] Please refer again Figure 3 、 Figure 4 and Figure 5 In some embodiments, the pressure relief mechanism 24 is separately provided from the wall portion 213 , the wall portion 213 is provided with a pressure relief hole 2131 , and the pressure relief mechanism 24 is installed on the wall portion 213 and covers the pressure relief hole 2131 .

[0188] The phrase "pressure relief mechanism 24 is provided separately from wall portion 213, wall portion 213 is provided with a pressure relief hole 2131, and pressure relief mechanism 24 is mounted on wall portion 213 and covers pressure relief hole 2131" means that during manufacturing, pressure relief hole 2131 is provided on wall portion 213, and the pressure relief mechanism 24 and wall portion 213 are provided separately and ultimately connected together. For example, the pressure relief mechanism 24 can be welded to wall portion 213. The pressure relief mechanism 24 can be a bursting disk mounted on wall portion 213.

[0189] In some embodiments, the pressure relief mechanism 24 is disposed at the end of the pressure relief hole 2131 facing the electrode assembly 23 . The battery cell 20 includes a protective member 26 disposed at the end of the pressure relief hole 2131 facing away from the electrode assembly 23 and covering the pressure relief hole 2131 .

[0190] The pressure relief mechanism 24 is provided separately from the wall portion 213 and is installed on the wall portion 213 , thereby facilitating processing and manufacturing.

[0191] Optionally, the base material of the wall portion 213 is iron, and the pressure relief mechanism 24 is connected to the wall portion 213 by welding.

[0192] "The base material of wall portion 213 is iron" means that iron is the largest material by mass in wall portion 213. For example, wall portion 213 can be made of carbon steel or stainless steel. Carbon steel can be low carbon steel, medium carbon steel, or high carbon steel. For example, wall portion 213 can be made of 304 stainless steel, 305 stainless steel, 316 stainless steel, etc.

[0193] The base material of the pressure relief mechanism 24 and the wall portion 213 is both iron. This effectively enhances the structural strength of the wall portion 213 and the pressure relief mechanism 24, reduces the risk of deformation due to stress, and helps reduce the risk of premature valve opening and pressure relief by the pressure relief mechanism 24, thereby improving the service life and reliability of the battery cell 20. Furthermore, welding the pressure relief mechanism 24 to the wall portion 213 is easier, which helps reduce the risk of weld cracks between the pressure relief mechanism 24 and the end cap 212, thereby reducing the risk of leakage from the battery cell 20 and improving the reliability of the battery cell 20.

[0194] In other embodiments, the pressure relief mechanism 24 and the wall portion 213 are integrally formed.

[0195] Integrally formed means that the wall portion 213 and the pressure relief mechanism 24 are an integral structure when provided. For example, the pressure relief mechanism 24 can be formed on the wall portion 213 by stamping.

[0196] Integrating the pressure relief mechanism 24 with the wall portion 213 eliminates the need for additional welding or bonding processes, which helps reduce the risk of leakage from the pressure relief mechanism 24. Furthermore, during production, it is easier to ensure that the detonation pressures of multiple battery cells 20 produced are more consistent.

[0197] In some embodiments, the pressure relief mechanism 24 is made of 304 stainless steel, 305 stainless steel, or 316 stainless steel.

[0198] 304 stainless steel, 305 stainless steel and 316 stainless steel have the advantages of corrosion resistance, high temperature resistance and good processing performance. The pressure relief mechanism 24 manufactured using 304 stainless steel, 305 stainless steel or 316 stainless steel has high strength, which can reduce the risk of deformation of the pressure relief mechanism 24 due to force, and is beneficial to reducing the risk of the pressure relief mechanism 24 opening the valve to relieve pressure prematurely, which is beneficial to improving the service life and reliability of the battery cell 20, and is beneficial to improving the consistency of the detonation pressure of multiple battery cells 20.

[0199] The embodiment of the present application further provides a battery device 100 , which includes the above-mentioned battery cell 20 .

[0200] An embodiment of the present application further provides an electrical device, which includes the above-mentioned battery cell 20, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0201] According to some embodiments of this application, please refer to Figures 3 to 13 .

[0202] The embodiment of the present application provides a battery cell 20, which includes a shell 21 and a pressure relief mechanism 24. The shell 21 has a wall portion 213, and the pressure relief mechanism 24 is arranged on the wall portion 213. The base material of the pressure relief mechanism 24 is iron. The pressure relief mechanism 24 is provided with a first groove 241. The pressure relief mechanism 24 is configured to break along at least part of the first groove 241 when the pressure inside the shell 21 reaches a threshold value to release pressure. The first groove 241 has a first groove bottom surface 2411, which is an arc surface that is concave in the direction away from the notch 2412 of the first groove 241. The arc surface is arc-shaped in the cross section of the first groove 241. The cross section is perpendicular to the extension direction of the first groove 241. The base material of the pressure relief mechanism 24 is iron, which can effectively improve the structural strength of the pressure relief mechanism 24, reduce the risk of the pressure relief mechanism 24 opening the valve to release pressure prematurely, and is conducive to improving the service life and reliability of the battery cell 20. By setting the first groove bottom surface 2411 of the first groove 241 to be an arc surface that is concave in the direction of the groove opening 2412 away from the first groove 241, it is convenient to flow the material when stamping the first groove 241, which is beneficial to relieve stress concentration and to ensure that the bursting pressure of multiple battery cells 20 is consistent when manufacturing multiple battery cells 20, which is beneficial to improving the reliability of the battery cells 20.

[0203] In some embodiments, the arc surface is a circular arc surface, which defines the notch 2412 of the first groove 241. The circular arc surface defines the notch 2412 of the first groove 241, so that the cross-section of the first groove 241 is generally circular arc-shaped, which facilitates material flow during stamping and forming the first groove 241, helps alleviate stress concentration, helps maintain consistent burst pressure of multiple battery cells 20 when manufacturing multiple battery cells 20, and helps improve the reliability of the battery cells 20.

[0204] In other embodiments, the first groove 241 includes a first groove side surface 2413 and a second groove side surface 2414, which are arranged opposite each other along the width direction of the first groove 241. The first groove bottom surface 2411 connects the first groove side surface 2413 and the second groove side surface 2414. The first groove side surface 2413 and the second groove side surface 2414 define a notch 2412 of the first groove 241. The first groove bottom surface 2411 connects the first groove side surface 2413 and the second groove side surface 2414. The first groove side surface 2413 and the second groove side surface 2414 are flat, while the first groove bottom surface 2411 is an arcuate surface. This facilitates maintaining a small width of the first groove 241 when the depth of the first groove 241 is large, thereby facilitating control of the bursting pressure of the pressure relief mechanism 24. The first groove side surface 2413 and the second groove side surface 2414 define the groove opening 2412 of the first groove 241, so that the cross-sectional shape of the first groove 241 is relatively simple, which is beneficial to reducing the stress between the groove side surface and the first groove bottom surface 2411, alleviating stress concentration, and is beneficial to keeping the bursting pressure of multiple battery cells 20 consistent when manufacturing multiple battery cells 20, which is beneficial to improving the reliability of the battery cells 20.

[0205] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, characterized in that: include: a housing having a wall portion; a pressure relief mechanism disposed on the wall portion, wherein the base material of the pressure relief mechanism is iron and the pressure relief mechanism is provided with a first groove, and the pressure relief mechanism is configured to rupture along at least a portion of the first groove when the pressure inside the housing reaches a threshold value to release the pressure; The first groove has a first groove bottom surface, which is an arc surface concave in a direction away from the groove opening of the first groove. The arc surface is arc-shaped in the cross section of the first groove, and the cross section is perpendicular to the extension direction of the first groove.

2. The battery cell according to claim 1, characterized in that: The arc surface is a circular arc surface.

3. The battery cell according to claim 1, characterized in that: The arc surface defines a notch of the first groove.

4. The battery cell according to claim 1, characterized in that: The first groove includes a first groove side surface and a second groove side surface. Along the width direction of the first groove, the first groove side surface and the second groove side surface are arranged opposite to each other, and the first groove bottom surface connects the first groove side surface and the second groove side surface.

5. The battery cell according to claim 4, characterized in that: The first groove side surface and the second groove side surface define a groove opening of the first recess.

6. The battery cell according to claim 4, characterized in that: The first groove side surface and the second groove side surface are both inclined, and the distance between the first groove side surface and the second groove side surface gradually decreases from the groove opening to the first groove bottom surface.

7. The battery cell according to claim 4, characterized in that: The first groove side surface is parallel to the second groove side surface.

8. The battery cell according to claim 4, characterized in that: The first groove also includes a third groove side surface and a fourth groove side surface. Along the width direction of the first groove, the third groove side surface and the fourth groove side surface are arranged opposite to each other. The first groove side surface connects one end of the first groove bottom surface and the third groove side surface, and the second groove side surface connects the other end of the first groove bottom surface and the fourth groove side surface.

9. The battery cell according to claim 8, characterized in that: The third groove side surface and the fourth groove side surface define a groove opening of the first recess.

10. The battery cell according to claim 8, characterized in that: The first groove side surface is parallel to the second groove side surface; The third groove side surface and the fourth groove side surface are both inclined, and the distance between the third groove side surface and the fourth groove side surface gradually decreases from the groove opening to the bottom surface of the first groove.

11. The battery cell according to claim 8, characterized in that: The first groove side surface and the second groove side surface are both inclined, and along the thickness direction of the wall portion, the distance between the first groove side surface and the second groove side surface gradually decreases from the groove opening to the bottom surface of the first groove; The third groove side surface is parallel to the fourth groove side surface.

12. The battery cell according to claim 8, characterized in that: The first groove side surface and the second groove side surface are both inclined, and the distance between the first groove side surface and the second groove side surface gradually decreases from the groove opening to the bottom surface of the first groove; The third groove side surface and the fourth groove side surface are both inclined, and the distance between the third groove side surface and the fourth groove side surface gradually decreases from the groove opening to the bottom surface of the first groove; The angle formed by the first groove side surface and the second groove side surface is a, the angle formed by the third groove side surface and the fourth groove side surface is b, and a>b or a<b.

13. The battery cell according to any one of claims 1 to 12, characterized in that: The pressure relief mechanism is provided with a second groove, the first groove and the second groove are arranged along the thickness direction of the wall portion, the second groove has a second groove bottom surface, and the notch of the first groove is formed on the second groove bottom surface.

14. The battery cell according to claim 13, characterized in that: The pressure relief mechanism has a first surface and a second surface arranged opposite to each other in the thickness direction of the wall portion, the second groove includes a plurality of grooves arranged in sequence from the first surface to the second surface, and in two adjacent grooves, the first groove farther from the first surface is arranged at the groove bottom surface of the first groove closer to the first surface; The bottom surface of the first-stage groove farthest from the first surface among the multi-stage grooves is the second groove bottom surface.

15. The battery cell according to any one of claims 1 to 12, characterized in that: The pressure relief mechanism is separately provided with the wall portion, the wall portion is provided with a pressure relief hole, and the pressure relief mechanism is installed on the wall portion and covers the pressure relief hole.

16. The battery cell according to claim 15, characterized in that: The base material of the wall portion is iron, and the pressure relief mechanism is connected to the wall portion by welding.

17. The battery cell according to any one of claims 1 to 12, characterized in that: The pressure relief mechanism is integrally formed with the wall portion.

18. The battery cell according to any one of claims 1 to 12, characterized in that: The pressure relief mechanism is made of 304 stainless steel, 305 stainless steel or 316 stainless steel.

19. A battery device, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 18.

20. An electrical device, characterized in that: The battery cell comprises a battery cell according to any one of claims 1 to 18, wherein the battery cell is used to provide electrical energy to the electrical device.

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