Battery monomer, battery and electric equipment

Abstract

The invention provides a battery monomer, a battery and electric equipment. The battery cell includes a housing and a pressure relief member. The shell comprises a first wall part, the first wall part is provided with a first groove, the first groove comprises a groove side face and a first groove bottom face, the groove side face is arranged around the first groove bottom face in a surrounding mode, and the first groove bottom face is provided with a pressure relief hole. The pressure relief component is arranged in the first groove, abuts against the first groove bottom face and covers the pressure relief hole. A gap is formed between at least part of the groove side face in the circumferential direction of the first groove and the pressure relief component. When the first wall part deforms due to expansion of the battery monomer, the gap between the pressure relief component and the groove side surface can provide a buffer space for the pressure relief component, so that the risk of deformation of the pressure relief component caused by extrusion of the groove side surface on the pressure relief component is reduced, and the risk of opening the pressure relief component in advance in the normal use process of the battery monomer is further reduced; and the service life of the pressure relief component is prolonged, so that the service life of the single battery is prolonged.

Description

Battery cells, batteries and electrical equipment Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0002] Batteries are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes and power tools, etc.

[0003] In battery technology, pressure relief components can be installed in battery cells to relieve pressure in the event of thermal runaway. However, for typical battery cells, these components can prematurely open during normal use, impacting the battery's service life. Therefore, improving the service life of battery cells is a pressing technical challenge in battery technology.

[0004] Summary of the Invention

[0005] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can effectively increase the service life of the battery cell.

[0006] In a first aspect, an embodiment of the present application provides a battery cell, comprising a shell and a pressure relief component; the shell comprises a first wall portion, the first wall portion is provided with a first groove, the first groove comprises a groove side surface and a first groove bottom surface, the groove side surface is arranged around the first groove bottom surface, and the first groove bottom surface is provided with a pressure relief hole; the pressure relief component is arranged in the first groove, the pressure relief component abuts against the first groove bottom surface and covers the pressure relief hole; wherein, a gap is formed between the groove side surface and the pressure relief component along at least a portion of the circumference of the first groove.

[0007] In the above technical solution, a gap is formed between the groove side surface along the circumference of at least a portion of the first groove and the pressure relief component. When the first wall portion is deformed due to the expansion of the battery cell, the gap between the pressure relief component and the groove side surface can provide a buffer space for the pressure relief component, thereby reducing the risk of the groove side surface squeezing the pressure relief component and causing deformation of the pressure relief component, thereby reducing the risk of the pressure relief component opening prematurely during normal use of the battery cell, and improving the service life of the pressure relief component, thereby improving the service life of the battery cell.

[0008] In some embodiments, the groove side includes a first region that forms a gap with the pressure relief component. Along the circumference of the first groove, the length of the first region is L1, and the circumference of the groove side is L, satisfying the following relationship: 0.2 ≤ L1 / L ≤ 1. This creates a gap between the longer circumferential portion of the groove side and the pressure relief component, reducing the extent to which the groove side compresses the pressure relief component when the first wall portion deforms, further reducing the risk of premature opening of the pressure relief component during normal use of the battery cell.

[0009] In some embodiments, 0.5≤L1 / L≤1.

[0010] In some embodiments, a gap is formed between the groove side surface and the pressure relief component along the entire circumference of the first groove. This allows a gap to exist between the groove side surface and the pressure relief component along the entire circumference. This gap is an annular structure surrounding the pressure relief component, further reducing the squeezing effect of the groove side surface on the pressure relief component when the first wall portion deforms, further reducing the risk of premature opening of the pressure relief component during normal use of the battery cell.

[0011] In some embodiments, the pressure relief component is welded to the bottom wall of the first groove and a weld mark is formed, thereby fixing the pressure relief component to the first wall and improving the connection strength between the pressure relief component and the first wall.

[0012] In some embodiments, the projection of the weld mark along the thickness direction of the first wall is entirely located on the pressure relief component. This allows the pressure relief component to be welded to the bottom wall of the first groove via penetration welding. This simple welding method allows the weld mark formed after welding to pass through the pressure relief component and embed into the bottom wall of the first groove, thereby improving the connection strength between the pressure relief component and the first wall. Furthermore, because the projection of the weld mark along the thickness direction of the first wall is located on the pressure relief component, the weld mark does not protrude beyond the edge of the pressure relief component and is not located within the gap between the pressure relief component and the side surface of the groove. This reduces the risk of the side surface of the groove squeezing the pressure relief component through the weld mark when the first wall deforms.

[0013] In some embodiments, the pressure relief component and the bottom wall of the groove have an overlapping area, comprising a first weld area located on the pressure relief component and a second weld area located on the bottom wall of the groove. The second weld area defines a pressure relief hole. The first weld area and the second weld area are welded together to form a weld mark. Along the thickness direction of the first wall, the minimum thickness of the first weld area is H1, the minimum thickness of the second weld area is H2, and the maximum height of the weld mark is H3, satisfying the following conditions: H1 < H3 ≤ H1 + H2. H3 > H1 allows a portion of the weld mark to be embedded in the second weld area, achieving a stable connection between the pressure relief component and the bottom wall of the groove. H3 ≤ H1 + H2 ensures that the weld mark does not completely penetrate the second weld area, reducing the risk of the second weld area being welded through.

[0014] In some embodiments, 0.2 mm ≤ H1 ≤ 1 mm. H1 ≥ 0.2 mm ensures that the first welding area has sufficient thickness and strength; H1 ≤ 1 mm ensures that the thickness of the first welding area is not too large, which is beneficial for reducing welding power and improving welding effect.

[0015] In some embodiments, 0.45 mm ≤ H1 ≤ 0.75 mm.

[0016] In some embodiments, 0.2 mm ≤ H2 ≤ 5 mm. H2 ≥ 0.2 mm ensures that the second welding zone has sufficient thickness, reducing the risk of the second welding zone being welded through; H2 ≤ 5 mm ensures that the thickness of the second welding zone is not too large, saving materials and having better economic efficiency.

[0017] In some embodiments, 0.8 mm ≤ H2 ≤ 3 mm.

[0018] In some embodiments, along a first direction, at least one end of the pressure relief component is formed with a first side surface, the groove side surface includes a second side surface facing the first side surface, a gap is formed between the first side surface and the second side surface, and the first direction intersects with the thickness direction of the first wall portion. Due to the gap between the first side surface and the second side surface, when the wall portion deforms, the second side surface is less likely to squeeze the first side surface along the first direction, thereby reducing the risk of deformation of the pressure relief component due to squeezing force in the first direction.

[0019] In some embodiments, the first side surface is parallel to the second side surface, so that the distance between the first side surface and the second side surface does not change significantly along the depth direction of the first groove, and the second side surface is unlikely to squeeze the first side surface along the first direction.

[0020] In some embodiments, the second side surface is parallel to the thickness direction of the first wall portion, which helps to reduce the difficulty of forming the first groove.

[0021] In some embodiments, the distance between the first side surface and the second side surface along the first direction gradually decreases along the depth direction of the first groove. When the first wall portion deforms, the portion of the second side surface closer to the bottom surface of the first groove deforms less, resulting in less squeezing effect on the first side surface. The portion of the second side surface closer to the notch of the first groove deforms more, resulting in greater squeezing effect on the first side surface. Gradually decreasing the distance between the first side surface and the second side surface along the first direction along the depth direction of the first groove can reduce the squeezing effect of the second side surface on the first side surface when the first wall portion deforms, and can also reduce the range of motion of the pressure relief component within the first groove along the first direction during installation, thereby reducing the difficulty of installing the pressure relief component.

[0022] In some embodiments, the second side surface is an inclined surface arranged at a non-zero angle with respect to the thickness direction of the first wall portion. By configuring the second side surface as an inclined surface, the distance between the first side surface and the second side surface along the first direction gradually decreases along the depth direction of the first groove. During assembly, the inclined second side surface can guide the pressure relief component, facilitating its entry into the first groove.

[0023] In some embodiments, at least a portion of the longitudinal cross-section of the second side surface is arc-shaped, and the longitudinal cross-section is parallel to the first direction and the thickness direction of the first wall portion. This facilitates gradually decreasing the distance between the first side surface and the second side surface along the first direction along the depth direction of the first groove. During assembly, the second side surface can guide the pressure relief component, facilitating its entry into the first groove.

[0024] In some embodiments, the first side surface is parallel to the thickness direction of the first wall portion, which helps to reduce the difficulty of forming the pressure relief component.

[0025] In some embodiments, the pressure relief component has a weakened portion configured to rupture to release internal pressure from the battery cell. The pressure relief component is welded to the bottom wall of the first groove and forms a weld mark. Along the first direction, the weld mark is at least partially located between the first side surface and the weakened portion. The maximum distance between the first side surface and the second side surface is B1, the minimum distance between the weld mark and the first side surface is B2, and the minimum distance between the weld mark and the weakened portion is B3, satisfying the following: 0.3 ≤ (B1 + B2) / B3 ≤ 2.5. This reduces the impact of the weld mark on the strength of the weakened portion and reduces the squeezing effect of the second side surface on the first side surface when the first wall surface deforms, thereby enhancing the cushioning effect of the gap on the pressure relief component when the first wall surface deforms.

[0026] In some embodiments, 0.8≤(B1+B2) / B3≤1.5.

[0027] In some embodiments, 0.05 mm ≤ B1 ≤ 20 mm. B1 ≥ 0.05 mm increases the distance between the first side surface and the second side surface, reducing the squeezing effect of the second side surface on the first side surface when the first wall portion deforms. B1 ≤ 20 mm prevents the distance between the first side surface and the second side surface from being too large, reduces the size of the first groove in the first direction, and reduces the difficulty of forming the first groove.

[0028] In some embodiments, 1.5 mm ≤ B1 ≤ 10 mm.

[0029] In some embodiments, 0.1 mm ≤ B2 ≤ 20 mm. When B2 ≥ 0.1 mm, the distance between the weld mark and the first side surface is not too small, thereby reducing the risk of deformation in the area near the first side surface during welding of the pressure relief component, thereby reducing the risk of the gap being reduced. When B2 ≤ 20 mm, the distance between the weld mark and the first side surface is not too large, thereby eliminating the need to oversize the pressure relief component and facilitating miniaturization of the pressure relief component.

[0030] In some embodiments, 2 mm ≤ B2 ≤ 10 mm.

[0031] In some embodiments, 1 mm ≤ B3 ≤ 20 mm. B3 ≥ 1 mm ensures a sufficient distance between the weld mark and the weak portion, thereby reducing the impact of the weld mark on the weak portion and reducing the impact on the bursting pressure of the pressure relief component caused by the distance between the weld mark and the weak portion being too small. B3 ≤ 20 mm prevents the distance between the weld mark and the weak portion from being too large, thereby facilitating miniaturization of the pressure relief component.

[0032] In some embodiments, 3 mm ≤ B3 ≤ 10 mm.

[0033] In some embodiments, the first wall portion is a rectangular wall portion, and the first direction is parallel to the length direction of the first wall portion. Because the first direction is parallel to the length direction of the first wall portion, a gap is formed between the first side surface and the second side surface along the length direction of the first wall portion, that is, a gap is formed between the pressure relief component and the groove side surface of the first groove along the length direction of the first wall portion. Because the first wall portion is a rectangular wall portion, when the battery cell expands, the phase change amount of the first wall portion along the length direction is greater. This gap can provide a buffer space for the pressure relief component along the length direction of the first wall portion, reducing the risk of the pressure relief component being squeezed by the groove side surface along the length direction of the first wall portion, causing deformation of the pressure relief component.

[0034] In some embodiments, along the thickness direction of the first wall portion, the pressure relief component is located on the side of the pressure relief hole away from the interior of the housing. In this way, the pressure relief component can be installed on the outside of the first wall portion, making it more convenient to install the pressure relief component.

[0035] In some embodiments, the battery cell further includes a protective member located along the thickness direction of the first wall portion on a side of the pressure relief component facing away from the interior of the housing, and the protective member covers the first groove. The protective member can protect the pressure relief component and reduce the risk of foreign matter (impurities, electrolyte) entering the first groove and corroding the pressure relief component.

[0036] In some embodiments, the first wall portion has an outer surface facing away from the interior of the housing along its thickness, and the outer surface is provided with a second groove. The first groove is provided at the bottom of the second groove, and the protective member is at least partially accommodated in the second groove. This can reduce the height of the protective member protruding from the outer surface of the first wall portion, thereby reducing the space occupied by the protective member outside the housing.

[0037] In some embodiments, the pressure relief component is located on the side of the pressure relief hole facing the interior of the housing along the thickness direction of the first wall. In this way, the pressure relief component can be installed on the inner side of the first wall, and the first wall can protect the pressure relief component and reduce the risk of damage to the first wall by external components.

[0038] In some embodiments, the battery cell further includes a protective member located along the thickness direction of the first wall portion on a side of the pressure relief hole facing away from the interior of the housing, and covering the pressure relief hole. The protective member can protect the pressure relief component and reduce the risk of foreign matter (impurities, electrolyte) entering the pressure relief hole and corroding the pressure relief component.

[0039] In some embodiments, the housing comprises a shell and an end cover, the shell has an opening, and the end cover closes the opening; wherein the end cover is the first wall portion; and / or, at least one wall portion of the shell is the first wall portion.

[0040] In a second aspect, an embodiment of the present application provides a battery, comprising a battery cell provided by any embodiment of the first aspect.

[0041] In a third aspect, an embodiment of the present application provides an electrical device, comprising a battery cell provided by any embodiment of the first aspect. 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] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0044] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0045] FIG3 is an exploded view of a battery cell provided in some embodiments of the present application;

[0046] FIG4 is a cross-sectional view of a battery cell provided in some embodiments of the present application;

[0047] FIG5 is an isometric view of the battery cell shown in FIG4 (the pressure relief component is separated from the first wall portion);

[0048] FIG6 is a partial view of the pressure relief component and the first wall portion shown in FIG5 after being assembled;

[0049] FIG7 is a partial view of the first wall portion shown in FIG6;

[0050] FIG8 is a top view of the assembled pressure relief component and the first wall portion according to some embodiments of the present application;

[0051] FIG9 is a top view of the first wall portion shown in FIG8 ;

[0052] FIG10 is a top view of the assembled pressure relief component and the first wall portion according to other embodiments of the present application;

[0053] FIG11 is a partial view of the assembled pressure relief component and the first wall portion according to some embodiments of the present application;

[0054] FIG12 is a partial view of the assembled pressure relief component and the first wall portion according to other embodiments of the present application;

[0055] FIG13 is a partial view of the assembled pressure relief component and the first wall portion according to some other embodiments of the present application;

[0056] FIG14 is a partial enlarged view of the battery cell at point A shown in FIG4 ;

[0057] FIG15 is an isometric view of a battery cell (the pressure relief component and the protective member are separated from the first wall portion) provided in some other embodiments of the present application;

[0058] FIG16 is a partial view of a battery cell provided in some embodiments of the present application;

[0059] FIG17 is a partial view of a battery cell provided in some other embodiments of the present application;

[0060] FIG18 is a partial view of a battery cell provided in some other embodiments of the present application;

[0061] FIG19 is an exploded view of a battery cell provided in some other embodiments of the present application;

[0062] FIG20 is a cross-sectional view of the battery cell shown in FIG19;

[0063] FIG21 is a partial enlarged view of the battery cell at position B shown in FIG20 ;

[0064] FIG22 is a partial view of the assembled pressure relief component, the protective component, and the first wall portion provided by still other embodiments of the present application;

[0065] FIG23 is a partial view of the assembled pressure relief component, the protective component, and the first wall portion provided in some other embodiments of the present application;

[0066] FIG24 is an exploded view of a battery cell provided in some further embodiments of the present application;

[0067] FIG25 is a cross-sectional view of the battery cell shown in FIG24 .

[0068] Icons: 1-housing; 11-shell; 12-end cover; 13-first wall; 131-first groove; 1311-groove side; 1311a-first area; 1311b-second side; 1311c-third side; 1312-first groove bottom; 1313-groove bottom wall; 1313a-second welding area; 132-pressure relief hole; 133-welding stamp; 134-first surface; 135-outer surface; 136-second groove; 137-protrusion; 2-electrode assembly; 21-ear; 3 -electrode terminal; 4-current collecting member; 5-first insulating member; 6-second insulating member; 7-pressure relief member; 71-outer peripheral surface; 711-first side surface; 72-first welding area; 73-weak part; 74-notched groove; 75-sunk groove; 8-gap; 9-protective member; 10-battery cell; 20-housing; 201-first part; 202-second part; 100-battery; 200-controller; 300-motor; 1000-vehicle; X-length direction; Y-width direction; Z-thickness direction. DETAILED DESCRIPTION

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] The term "plurality" used in this application refers to two or more (including two).

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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 silver-plated surface, stainless steel with a silver-plated surface, 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.).

[0081] 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 battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. 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 / 3 Mn 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 0.05 O2) and at least one of its modified compounds, etc.

[0082] In some embodiments, a positive electrode may be a metal foam. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam, among others. When a metal foam is used as the positive electrode, the surface of the metal foam may or may not be provided with a positive electrode active material. For example, a lithium source material, potassium metal, or sodium metal may be filled and / or deposited within the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

[0083] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0084] 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 or stainless steel with a silver surface treatment, 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, or carbon foam. 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.).

[0085] 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.

[0086] 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.

[0087] 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 batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0088] 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.

[0089] In some embodiments, the separator is a separator membrane, which can be any known porous separator membrane with good chemical and mechanical stability.

[0090] 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.

[0091] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0096] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0097] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, or the like.

[0098] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0099] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0100] 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.

[0101] In some embodiments, the electrode assembly is a laminate structure.

[0102] 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.

[0103] 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.

[0104] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0105] 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.

[0106] 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.

[0107] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0108] 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.

[0109] 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.

[0110] 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 prismatic batteries. Polygonal prismatic batteries are, for example, hexagonal prismatic batteries.

[0111] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0112] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0113] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0114] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0115] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0116] The development of battery technology must take into account multiple design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, the reliability of battery cells must also be considered.

[0117] In battery technology, pressure relief components can be installed in battery cells to improve their reliability. These components have a significant impact on battery reliability. For example, short circuits and overcharging can cause thermal runaway within the battery cell, leading to a sudden increase in pressure or temperature. In these situations, the pressure relief components release internal pressure and temperature, reducing the likelihood of explosion or fire.

[0118] In a battery cell, a pressure relief component can be integrally formed with the wall of the housing, or a separate pressure relief component can be used. For a separate pressure relief component, a pressure relief hole can be provided in the wall of the housing, and the pressure relief component can be fixed to the wall of the housing and cover the pressure relief hole. In the event of thermal runaway of the battery cell, the pressure relief component releases the pressure inside the battery cell.

[0119] To reduce the impact of external components on the pressure relief component, a groove can be provided on the wall of the housing, with a pressure relief hole provided at the bottom of the groove. The pressure relief component is accommodated within the groove and covers the pressure relief hole. Once the pressure relief component is accommodated within the groove, it forms an interference fit with the side surfaces of the groove. During normal use of the battery cell, the battery cell may expand, causing deformation of the wall of the housing. The side surfaces of the groove will squeeze the pressure relief component, causing deformation of the pressure relief component, which can easily cause the pressure relief component to break and open prematurely, shortening the service life of the battery cell.

[0120] In view of this, an embodiment of the present application provides a battery cell, which forms a gap between the pressure relief component and at least a portion of the groove side surface along the circumference of the groove. When the first wall portion is deformed due to the expansion of the battery cell, the gap between the pressure relief component and the groove side surface can provide a buffer space for the pressure relief component, thereby reducing the risk of the groove side surface squeezing the pressure relief component and causing deformation of the pressure relief component, thereby reducing the risk of the pressure relief component opening prematurely during normal use of the battery cell, and improving the service life of the pressure relief component, thereby improving the service life of the battery cell.

[0121] The battery cells described in the embodiments of the present application are suitable for batteries and electrical equipment using the battery cells.

[0122] Electrical equipment can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical equipment.

[0123] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0124] Please refer to Figure 1, which is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application. A battery 100 is disposed within vehicle 1000. Battery 100 can be located at the bottom, front, or rear of vehicle 1000. Battery 100 can be used to power vehicle 1000, for example, as an operating power source for vehicle 1000.

[0125] The vehicle 1000 may further include a controller 200 and a motor 300 . The controller 200 is used to control the battery 100 to supply power to the motor 300 , for example, to meet the power requirements of the vehicle 1000 during startup, navigation, and driving.

[0126] In some embodiments of the present application, the battery 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.

[0127] Please refer to Figure 2, which is an exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a battery cell 10 and a housing 20, wherein the battery cell 10 is accommodated in the housing 20.

[0128] The housing 20 is a component that houses the battery cells 10 and provides a storage space for the battery cells 10. The housing 20 can have various structures. In some embodiments, the housing 20 can include a first portion 201 and a second portion 202, which overlap to define a storage space for the battery cells 10. The first portion 201 and the second portion 202 can have various shapes, such as a rectangular parallelepiped or a cylindrical shape. The first portion 201 can be a hollow structure with one side open, and the second portion 202 can also be a hollow structure with one side open. The open side of the second portion 202 overlaps the open side of the first portion 201, thereby forming the housing 20 with a storage space. Alternatively, the first portion 201 can be a hollow structure with one side open, and the second portion 202 can be a plate-like structure. The second portion 202 overlaps the open side of the first portion 201, thereby forming the housing 20 with a storage space. The first portion 201 and the second portion 202 can be sealed by a sealing element, which can be a sealing ring, sealant, etc.

[0129] In the battery 100, there can be one or more battery cells 10. If there are multiple battery cells 10, the multiple battery cells 10 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 10. Multiple battery cells 10 can be connected in series, parallel, or in a hybrid connection to form a battery module, which can then be connected in series, parallel, or in a hybrid connection to form a single unit and housed within the housing 20. Alternatively, all battery cells 10 can be directly connected in series, parallel, or in a hybrid connection, and then the entire unit formed by all battery cells 10 can be housed within the housing 20.

[0130] 3 and 4 , FIG3 is an exploded view of a battery cell 10 provided in some embodiments of the present application, and FIG4 is a cross-sectional view of a battery cell 10 provided in some embodiments of the present application. The battery cell 10 may include a housing 1 and an electrode assembly 2 , wherein the electrode assembly 2 is accommodated in the housing 1 .

[0131] In some embodiments, the housing 1 may include a shell 11 and an end cover 12 , wherein the shell 11 has an opening and the end cover 12 closes the opening of the shell 11 .

[0132] The housing 11 is a component for accommodating the electrode assembly 2. The housing 11 can be a hollow structure with an opening at one end, or a hollow structure with openings at opposite ends. The housing 11 can have various shapes, such as a cylinder or a rectangular parallelepiped. The housing 11 can be made of various materials, such as copper, iron, aluminum, steel, and aluminum alloys.

[0133] The end cap 12 is a component that closes the opening of the shell 11 to isolate the internal environment of the battery cell 10 from the external environment. The end cap 12 and the shell 11 together define a receiving space for accommodating the electrode assembly 2, electrolyte and other components. The end cap 12 can be connected to the shell 11 by welding or rolling to close the opening of the shell 11. The shape of the end cap 12 can be adapted to the shape of the shell 1. For example, the shell 11 is a rectangular parallelepiped structure, and the end cap 12 is a rectangular plate structure adapted to the shell 1. For another example, the shell 11 is a cylindrical structure, and the end cap 12 is a circular plate structure adapted to the shell 11. The material of the end cap 12 can also be a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, plastic, etc. The material of the end cap 12 and the shell 11 can be the same or different.

[0134] In an embodiment where the housing 11 is open at one end, one end cap 12 may be provided. In an embodiment where the housing 11 is open at two opposite ends, two end caps 12 may be provided, each of which closes the two openings of the housing 11, and the two end caps 12 and the housing 11 together define a receiving space.

[0135] In some embodiments, the battery cell 10 may further include an electrode terminal 3, which is disposed on the outer casing 1. The electrode terminal 3 is used to electrically connect to the tab 21 of the electrode assembly 2 to input or output electrical energy from the battery cell 10. The electrode terminal 3 may be disposed on the shell 11 of the outer casing 1 or on the end cap 12 of the outer casing 1. The electrode terminal 3 and the tab 21 may be directly connected, for example, by direct welding the electrode terminal 3 and the tab 21. The electrode terminal 3 and the tab 21 may also be indirectly connected, for example, by indirectly connecting the electrode terminal 3 and the tab 21 through a current collecting member 4. The current collecting member 4 may be a metal conductor, such as copper, iron, aluminum, steel, or an aluminum alloy.

[0136] As an example, as shown in Figures 3 and 4, the housing 11 is a hollow structure with an opening formed at one end. The housing 1 includes a single end cap 12, which closes the opening of the housing 11. Two electrode terminals 3 are provided on the end cap 12, one positive electrode terminal and one negative electrode terminal. A positive tab and a negative tab are formed on the end of the electrode assembly 2 facing the end cap 12. The positive electrode terminal is connected to the positive tab via a current collecting member 4, and the negative electrode terminal is connected to the negative tab via another current collecting member 4.

[0137] In some embodiments, referring to Figures 3 and 4 , the battery cell 10 may further include a first insulating member 5 and a second insulating member 6 . The first insulating member 5 and the second insulating member 6 are components that separate the housing 11 from the electrode assembly 2. The first insulating member 5 surrounds the electrode assembly 2, and the second insulating member 6 is disposed on the side of the electrode assembly 2 facing away from the end cap 12 . The first insulating member 5 and the second insulating member 6 are used to achieve insulation isolation between the housing 11 and the electrode assembly 2. The first insulating member 5 and the second insulating member 6 are made of an insulating material, such as plastic, rubber, etc.

[0138] It should be noted that there can be one or more electrode assemblies 2 in the housing 1. If there is one electrode assembly 2, the first insulating member 5 is wrapped around the electrode assembly 2; if there are multiple electrode assemblies 2, one first insulating member 5 can be provided for each electrode assembly 2, with each first insulating member 5 wrapped around one electrode assembly 2, or multiple electrode assemblies 2 can be formed as an integral component, with the first insulating member 5 wrapped around the integral component.

[0139] As an example, as shown in Figures 3 and 4, there are two electrode assemblies 2 in the housing 1, the first insulating member 5 is an insulating film wrapped around the two electrode assemblies 2, and the second insulating member 6 is a bottom support plate arranged at the bottom of the two electrode assemblies 2.

[0140] Please refer to Figures 5-7. Figure 5 is an isometric view of the battery cell 10 shown in Figure 4 (with the pressure relief component 7 separated from the first wall portion 13); Figure 6 is a partial view of the pressure relief component 7 and the first wall portion 13 shown in Figure 5 after assembly; and Figure 7 is a partial view of the first wall portion 13 shown in Figure 6. This embodiment of the present application provides a battery cell 10 comprising a housing 1 and a pressure relief component 7. The housing 1 comprises a first wall portion 13, which is provided with a first groove 131. The first groove 131 comprises groove side surfaces 1311 and a first groove bottom surface 1312. The groove side surfaces 1311 surround the first groove bottom surface 1312, and the first groove bottom surface 1312 is provided with a pressure relief hole 132. The pressure relief component 7 is disposed within the first groove 131, abutting against the first groove bottom surface 1312 and covering the pressure relief hole 132. A gap 8 is formed between the groove side surfaces 1311 and the pressure relief component 7 along at least a portion of the circumference of the first groove 131.

[0141] The pressure relief component 7 is a component that releases pressure from the battery cell 10. When the internal pressure of the battery cell 10 reaches a threshold, the pressure relief component 7 can be used to discharge the exhaust medium from the battery cell 10 to achieve the purpose of pressure relief. The exhaust medium includes, but is not limited to, electrolyte, dissolved or split positive and negative electrode sheets, separator fragments, reaction gases, flames, etc. The pressure relief component 7 can be a sheet-like component mounted on the outer casing 1. The pressure relief component 7 can be mounted on the shell 11 of the outer casing 1 or on the end cap 12 of the outer casing 1.

[0142] The first wall portion 13 can be the end cover 12 of the outer shell 1. It is understood that the pressure relief component 7 is provided on the end cover 12. The first wall portion 13 can also be at least one wall portion of the shell 11 in the outer shell 1. It is understood that the pressure relief component 7 is provided on the shell 11. The first wall portion 13 can be a circular wall portion, a polygonal wall portion, etc. The polygonal wall portion can be a triangular wall portion, a quadrilateral wall portion, a pentagonal wall portion, a hexagonal wall portion, etc. In some embodiments, the outer shell 1 is cylindrical, and the first wall portion 13 is a circular wall portion; in other embodiments, the outer shell 1 is rectangular, and the first wall portion 13 is a rectangular wall portion. The pressure relief component 7 can be fixed to the first wall portion 13, and there are various ways to connect the pressure relief component 7 and the first wall portion 13, such as welding, bonding, etc.

[0143] The first groove 131 can be formed in the first wall portion 13 in a variety of ways, such as stamping, milling, laser etching, etc. The groove side surface 1311 is a closed structure extending along the circumference of the first groove 131. Along the depth direction of the first groove 131, the notch of the first groove 131 is arranged opposite to the first groove bottom surface 1312, and the depth direction of the first groove 131 can be parallel to the thickness direction Z of the first wall portion 13. The first groove 131 can be a polygonal groove, a circular groove, etc. If the first groove 131 is a polygonal groove, the cross-section of the groove side surface 1311 is polygonal, and the first groove bottom surface 1312 can be polygonal; if the first groove 131 is circular, the cross-section of the groove side surface 1311 is circular, and the first groove bottom surface 1312 can be circular. Among them, the cross-section of the groove side surface 1311 is perpendicular to the depth direction of the first groove 131. The groove side surface 1311 may include multiple side surfaces, connected end to end along the circumference of the first groove 131. The side surfaces may be parallel to the thickness direction Z of the first wall portion 13, or perpendicular to the first groove bottom surface 1312. The side surfaces may also be inclined surfaces arranged at an obtuse angle to the first groove bottom surface 1312. Of course, the side surfaces may be flat or arcuate. If the side surfaces are arcuate, the side surfaces may be arcuate surfaces with a centerline parallel to the thickness direction Z of the first wall portion 13, or may be arcuate surfaces with a centerline perpendicular to the thickness direction Z of the first wall portion 13.

[0144] The pressure relief component 7 is disposed in the groove. The pressure relief component 7 can be located entirely within the first groove 131, or partially within the first groove 131 and partially outside the first groove 131. The pressure relief component 7 can directly contact the first groove bottom surface 1312, so that the pressure relief component 7 directly abuts the first groove bottom surface 1312; the pressure relief component 7 can also indirectly abut the first groove bottom surface 1312 through an intermediate component. For example, the pressure relief component 7 is welded to the groove bottom wall 1313 of the first groove 131, so that the pressure relief component 7 contacts the first groove bottom surface 1312, and the pressure relief component 7 directly abuts the first groove bottom surface 1312; for another example, the pressure relief component 7 is bonded to the groove bottom wall 1313 of the first groove 131 via an adhesive layer, so that the pressure relief component 7 indirectly abuts the first groove bottom surface 1312 via the adhesive layer.

[0145] The pressure relief component 7 covers the pressure relief hole 132, obstructing it. Along the thickness direction Z of the first wall portion 13, the projection of the hole wall of the pressure relief hole 132 can be entirely located within the pressure relief component 7. The pressure relief component 7 can be located on the side of the pressure relief hole 132 facing the interior of the housing 1 along the thickness direction Z of the first wall portion 13, or it can be located on the side of the pressure relief hole 132 facing away from the interior of the housing 1 along the thickness direction Z of the first wall portion 13. If the pressure relief component 7 is located on the side of the pressure relief hole 132 facing the interior of the housing 1 along the thickness direction Z of the first wall portion 13, the pressure relief component 7 separates the pressure relief hole 132 from the interior space of the housing 1. In the event of thermal runaway of the battery cell 10, the pressure relief component 7 is destroyed, connecting the pressure relief hole 132 to the interior space of the housing 1, and the exhaust medium inside the housing 1 can be discharged through the pressure relief hole 132. If the pressure relief component 7 is located on the side of the pressure relief hole 132 away from the interior of the shell 1 along the thickness direction Z of the first wall portion 13, the pressure relief hole 132 is connected to the internal space of the shell 1, and the pressure relief component 7 separates the pressure relief hole 132 from the external space of the shell 1. When the battery cell 10 thermally runs away, the pressure relief component 7 is destroyed, and the pressure relief hole 132 connects the internal space of the shell 1 with the external space of the shell 1. The discharge medium inside the shell 1 can be discharged through the pressure relief hole 132.

[0146] The circumference of the first groove 131 surrounds the depth direction of the first groove 131, and the circumference of the notch of the first groove 131 is the circumference of the first groove 131. The gap 8 may be formed between the groove side surface 1311 and the pressure relief component 7 along a portion of the circumference of the first groove 131, or the gap 8 may be formed between the groove side surface 1311 and the pressure relief component 7 along the entire circumference of the first groove 131. The pressure relief component 7 has an outer peripheral surface 71 facing the groove side surface 1311. The outer peripheral surface 71 is a closed structure extending along the circumference of the pressure relief component 7. If a gap 8 is formed between the groove side surface 1311 and the outer peripheral surface 71 of the pressure relief component 7 along a part of the circumference of the first groove 131, and no gap 8 is formed between the groove side surface 1311 and the outer peripheral surface 71 of the pressure relief component 7 along another part of the first groove 131, then a gap 8 is formed between the groove side surface 1311 and the pressure relief component 7 along a part of the circumference of the first groove 131, and the gap 8 is a non-closed structure extending along the circumference of the first groove 131; if a gap 8 is formed between the groove side surface 1311 and the outer peripheral surface 71 of the pressure relief component 7 along the entire circumference of the first groove 131, then a gap 8 is formed between the groove side surface 1311 and the pressure relief component 7 along the entire circumference of the first groove 131, and the gap 8 is a closed structure extending along the circumference of the first groove 131, that is, the gap 8 is an annular gap.

[0147] In this embodiment, a gap 8 is formed between the groove side surface 1311 and the pressure relief component 7 along at least a portion of the circumference of the first groove 131. When the first wall portion 13 is deformed due to the expansion of the battery cell 10, the gap 8 between the pressure relief component 7 and the groove side surface 1311 can provide a buffer space for the pressure relief component 7, thereby reducing the risk of the groove side surface 1311 squeezing the pressure relief component 7 and causing deformation of the pressure relief component 7, thereby reducing the risk of the pressure relief component 7 opening prematurely during normal use of the battery cell 10, thereby increasing the service life of the pressure relief component 7, and thereby increasing the service life of the battery cell 10.

[0148] In some embodiments, please refer to Figures 8 and 9. Figure 8 is a top view of the assembled pressure relief component 7 and first wall portion 13 provided in some embodiments of the present application; Figure 9 is a top view of the first wall portion 13 shown in Figure 8. The groove side surface 1311 (shown in Figure 7) includes a first region 1311a that forms a gap 8 with the pressure relief component 7. Along the circumference of the first groove 131, the length of the first region 1311a is L1, and the circumference of the groove side surface 1311 is L, satisfying the following: 0.2 ≤ L1 / L ≤ 1.

[0149] The length of the first region 1311a is the total length of the portion of the groove side surface 1311 that forms the gap 8 with the pressure relief component 7 along the circumference of the first groove 131. When measuring the length of the first region 1311a and the circumference of the groove side surface 1311, the measurement can be made along the edge of the groove side surface 1311 located at the notch of the first groove 131.

[0150] L1 / L can be any point value among 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc., or a range of values ​​between any two of them.

[0151] As an example, as shown in Figures 8 and 9, the groove side surface 1311 includes two second side surfaces 1311b and two third side surfaces 1311c. The first wall portion 13 is a rectangular wall portion. The two second side surfaces 1311b are arranged opposite each other along the length direction X of the first wall portion 13, and the two third side surfaces 1311c are arranged opposite each other along the width direction Y of the first wall portion 13. One second side surface 1311b, one third side surface 1311c, another second side surface 1311b, and another third side surface 1311c are sequentially connected end to end to form a closed structure. The second side surface 1311b extends along the width direction Y of the first wall portion 13, and the third side surface 1311c is an arc surface. A gap 8 is formed between the two second side surfaces 1311b and the pressure relief component 7, and only a portion of each third side surface 1311c forms a gap 8 with the pressure relief component 7. It can be understood that the parts of the two third side surfaces 1311c and the pressure relief component 7 forming the gap 8 and the two second side surfaces 1311b constitute the first area 1311a. Along the circumference of the first groove 131, the total length of the parts of the two third side surfaces 1311c and the pressure relief component 7 forming the gap 8 and the two second side surfaces 1311b is the length of the first area 1311a, and the total length of the two second side surfaces 1311b and the two third side surfaces 1311c is the circumference of the groove side surface 1311.

[0152] In this embodiment, 0.2≤L1 / L≤1, so that a gap 8 is formed between the longer part of the groove side surface 1311 in the circumferential direction and the pressure relief component 7, reducing the extrusion range of the groove side surface 1311 on the pressure relief component 7 when the first wall portion 13 is deformed, and further reducing the risk of the pressure relief component 7 opening prematurely during normal use of the battery cell 10.

[0153] In some embodiments, 0.5≤L1 / L≤1.

[0154] In this embodiment, L1 / L can be any one of the point values ​​of 0.5, 0.53, 0.55, 0.58, 0.6, 0.63, 0.65, 0.68, 0.7, 0.73, 0.75, 0.78, 0.8, 0.83, 0.85, 0.88, 0.9, 0.93, 0.95, 0.98, 1, etc., or a range value between any two of them.

[0155] In some embodiments, please refer to Figure 10, which is a top view of the pressure relief component 7 and the first wall portion 13 after assembly according to other embodiments of the present application. A gap 8 is formed between the groove side surface 1311 and the pressure relief component 7 along the entire circumference of the first groove 131.

[0156] It is understood that the gap 8 formed between the groove side surface 1311 and the outer peripheral surface 71 of the pressure relief component 7 is an annular gap extending along the circumference of the first groove 131. In this embodiment, the first area 1311a is the groove side surface 1311, and L1 / L=1.

[0157] In this embodiment, there is a gap 8 around the entire circumference of the groove side 1311 and the pressure relief component 7. The gap 8 is an annular structure surrounding the pressure relief component 7, further reducing the squeezing effect of the groove side 1311 on the pressure relief component 7 when the first wall portion 13 is deformed, further reducing the risk of the pressure relief component 7 opening prematurely during normal use of the battery cell 10.

[0158] In some embodiments, please refer to Figure 11, which is a partial view of the pressure relief component 7 and the first wall portion 13 after assembly. The pressure relief component 7 is welded to the bottom wall 1313 of the first groove 131, and a weld mark 133 is formed.

[0159] The bottom wall 1313 of the first groove 131 is a substantial portion of the pressure relief component 7, located below the first groove bottom surface 1312 along the depth direction of the first groove 131, and having a thickness. The welded portion 133 is formed by welding the pressure relief component 7 to the bottom wall 1313. The welded portion 133 can be formed by fusing a portion of the pressure relief component 7 and a portion of the bottom wall 1313 together. The welded portion 133 can be an annular structure extending along the circumference of the pressure relief component 7, a multi-segment structure spaced apart along the circumference of the pressure relief component 7, or a long strip extending along a straight path.

[0160] In this embodiment, the pressure relief component 7 is welded to the groove bottom wall 1313 , so that the pressure relief component 7 is fixed to the first wall portion 13 , thereby improving the connection strength between the pressure relief component 7 and the first wall portion 13 .

[0161] In some embodiments, please continue to refer to FIG. 11 , along the thickness direction Z of the first wall portion 13 , the projections of the weld marks 133 are all located on the pressure relief component 7 .

[0162] When viewed along the thickness direction Z of the first wall portion 13, the entire welded portion 133 is located within the region defined by the outer edge of the pressure relief component 7. The welded portion 133 does not have any portion located outside the region defined by the outer edge of the pressure relief component 7. The welded portion 133 includes a portion located within the pressure relief component 7 and a portion located within the groove bottom wall 1313.

[0163] In this embodiment, the pressure relief component 7 can be welded to the bottom wall 1313 of the first groove 131 by penetration welding. This welding method is simple, and the weld mark 133 formed after welding can pass through the pressure relief component 7 and embed into the bottom wall 1313 of the first groove 131, thereby improving the connection strength between the pressure relief component 7 and the first wall portion 13. In addition, because the projection of the weld mark 133 along the thickness direction Z of the first wall portion 13 is located on the pressure relief component 7, the weld mark 133 does not protrude from the edge of the pressure relief component 7. Furthermore, the weld mark 133 is not located within the gap 8 between the pressure relief component 7 and the groove side surface 1311, thereby reducing the risk of the groove side surface 1311 squeezing the pressure relief component 7 through the weld mark 133 when the first wall portion 13 deforms.

[0164] Continuing with FIG. 11 , in some embodiments, the pressure relief component 7 and the groove bottom wall 1313 have an overlapping area. The pressure relief component 7 includes a first welding area 72 located on the pressure relief component 7 and a second welding area 1313a located on the groove bottom wall 1313. The second welding area 1313a defines a pressure relief hole 132. The first welding area 72 and the second welding area 1313a are welded together to form a weld mark 133. Along the thickness direction Z of the first wall portion 13, the minimum thickness of the first welding area 72 is H1, the minimum thickness of the second welding area 1313a is H2, and the maximum height of the weld mark 133 is H3, satisfying the following: H1<H3≤H1+H2.

[0165] The overlapping area is the portion where the pressure relief component 7 and the groove bottom wall 1313 overlap along the thickness direction Z of the first wall portion 13. The first welded area 72 is the portion where the pressure relief component 7 and the groove bottom wall 1313 overlap along the thickness direction Z of the first wall portion 13. The second welded area 1313a is the portion where the groove bottom wall 1313 and the pressure relief component 7 overlap along the thickness direction Z of the first wall portion 13. The second welded area 1313a can be the groove bottom wall 1313 or a portion of the groove bottom wall 1313. It is understood that, when viewed along the thickness direction Z of the first wall portion 13, the first welded area 72 and the second welded area 1313a overlap.

[0166] Along the thickness direction Z of the first wall portion 13, the thickness of the first weld zone 72 at its thinnest location is the minimum thickness of the first weld zone 72. If the thickness of the first weld zone 72 is uniform, the thickness of any region of the first weld zone 72 is the minimum thickness of the first weld zone 72. Along the thickness direction Z of the first wall portion 13, the thickness of the second weld zone 1313a at its thinnest location is the minimum thickness of the second weld zone 1313a. If the thickness of the second weld zone 1313a is uniform, the thickness of any region of the second weld zone 1313a is the minimum thickness of the second weld zone 1313a. The maximum height of the weld print 133 is the maximum dimension of the weld print 133 in the thickness direction Z of the first wall portion 13.

[0167] In this embodiment, H3>H1, so that part of the weld mark 133 can be embedded in the second welding area 1313a, thereby achieving a stable connection between the pressure relief component 7 and the groove bottom wall 1313; H3≤H1+H2, so that the weld mark 133 does not completely penetrate the second welding area 1313a, reducing the risk of the second welding area 1313a being welded through.

[0168] In some embodiments, 0.2 mm ≤ H1 ≤ 1 mm.

[0169] In this embodiment, H1 can be any point value among 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc., or a range value between any two of them.

[0170] In this embodiment, H1≥0.2mm, so that the first welding area 72 has sufficient thickness and sufficient strength; H1≤1mm, so that the thickness of the first welding area 72 is not too large, which is conducive to reducing welding power and improving welding effect.

[0171] In some embodiments, 0.45 mm ≤ H1 ≤ 0.75 mm.

[0172] In this embodiment, H1 can be any point value of 0.45mm, 0.48mm, 0.5mm, 0.53mm, 0.55mm, 0.58mm, 0.6mm, 0.63mm, 0.65mm, 0.68mm, 0.7mm, 0.73mm, 0.75mm, etc., or a range value between any two of them.

[0173] In some embodiments, 0.2 mm ≤ H2 ≤ 5 mm.

[0174] In this embodiment, H2 can be any point value of 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc., or a range value between any two of them.

[0175] In this embodiment, H2≥0.2mm, so that the second welding area 1313a has sufficient thickness, reducing the risk of the second welding area 1313a being welded through; H2≤5mm, so that the thickness of the second welding area 1313a is not too large, saving materials and having better economy.

[0176] In some embodiments, 0.8 mm ≤ H2 ≤ 3 mm.

[0177] In this embodiment, H2 can be any point value of 0.8mm, 1mm, 1.3mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.5mm, 2.8mm, 3mm, etc., or a range value between any two of them.

[0178] In some embodiments, please continue to refer to Figure 11. Along the first direction, at least one end of the pressure relief component 7 is formed with a first side surface 711, the groove side surface 1311 includes a second side surface 1311b facing the first side surface 711, and a gap 8 is formed between the first side surface 711 and the second side surface 1311b. The first direction intersects with the thickness direction Z of the first wall portion 13.

[0179] The first direction may be perpendicular to the thickness direction Z of the first wall portion 13, or may be arranged at an acute or obtuse angle. If the first wall portion 13 is a circular wall portion, the first direction may be parallel to the radial direction of the first wall portion 13. If the first wall portion 13 is a polygonal wall portion, for example, taking the first wall portion 13 as a rectangular wall portion, the first direction may be parallel to the length direction X of the first wall portion 13, or parallel to the width direction Y of the first wall portion 13. In the embodiment shown in Figure 11, the first wall portion 13 is a rectangular wall portion, the first direction is parallel to the length direction X of the first wall portion 13, and the first direction is perpendicular to the thickness direction Z of the first wall portion 13.

[0180] The first side surface 711 is the end surface of the pressure relief component 7 along the first direction. The first side surface 711 is a portion of the outer peripheral surface 71 (shown in FIG. 10 ) of the pressure relief component 7. The number of first side surfaces 711 in the outer peripheral surface 71 can be one or two. The second side surface 1311b is a portion of the groove side surface 1311. The second side surface 1311b corresponds one-to-one with the first side surface 711. The number of second side surfaces 1311b in the groove side surface 1311 can be one or two. As an example, along the first direction, a first side surface 711 is formed at both ends of the pressure relief component 7. The groove side surface 1311 includes two second side surfaces 1311b. A gap 8 is formed between one first side surface 711 and one second side surface 1311b. A gap 8 is also formed between the other first side surface 711 and the second side surface 1311b.

[0181] The first side surface 711 may be parallel to the thickness direction Z of the first wall portion 13, or may be set at a non-zero angle to the thickness direction Z of the first wall portion 13. The first side surface 711 may be a plane or a non-plane, such as a circular arc surface. If the first side surface 711 is a circular arc surface, the center line of the first side surface 711 may be parallel to or perpendicular to the thickness direction Z of the first wall portion 13. The second side surface 1311b may be parallel to the thickness direction Z of the first wall portion 13, or may be set at a non-zero angle to the thickness direction Z of the first wall portion 13. The second side surface 1311b may be a plane or a non-plane, such as a circular arc surface. If the second side surface 1311b is a circular arc surface, the center line of the second side surface 1311b may be parallel to or perpendicular to the thickness direction Z of the first wall portion 13.

[0182] In this embodiment, since a gap 8 is formed between the first side surface 711 and the second side surface 1311b, when the first wall portion 13 is deformed, the second side surface 1311b is unlikely to squeeze the first side surface 711 along the first direction, thereby reducing the risk of the pressure relief component 7 being deformed by the squeezing force in the first direction.

[0183] In some embodiments, referring again to FIG. 11 , the first side surface 711 is parallel to the second side surface 1311 b .

[0184] As an example, the first side surface 711 and the second side surface 1311 b are both planes.

[0185] As an example, the groove side 1311 includes two second side surfaces 1311b and two third side surfaces 1311c (shown in Figure 9), one second side surface 1311b, one third side surface 1311c, another second side surface 1311b and another third side surface 1311c are connected end to end to form a closed structure, the side surface of the pressure relief component 7 facing the third side surface 1311c is parallel to the third side surface 1311c, the third side surface 1311c is a circular arc surface, and the center line of the third side surface 1311c is parallel to the thickness direction Z of the first wall portion 13.

[0186] In this embodiment, the first side surface 711 is parallel to the second side surface 1311b, so that the distance between the first side surface 711 and the second side surface 1311b does not change significantly along the depth direction of the first groove 131, and it is difficult for the second side surface 1311b to squeeze the first side surface 711 along the first direction.

[0187] In some embodiments, referring again to FIG. 11 , the second side surface 1311 b is parallel to the thickness direction Z of the first wall portion 13 .

[0188] As an example, the second side surface 1311 b and the first groove bottom surface 1312 are both planes, and the second side surface 1311 b is perpendicular to the first groove bottom surface 1312 (shown in FIG. 7 ).

[0189] In this embodiment, the second side surface 1311 b is parallel to the thickness direction Z of the first wall portion 13 , which can simplify the structure of the first wall portion 13 and help reduce the difficulty of forming the first groove 131 .

[0190] In some embodiments, referring to Figures 12 and 13, Figure 12 is a partial view of the pressure relief component 7 and the first wall portion 13 after being assembled according to other embodiments of the present application; Figure 13 is a partial view of the pressure relief component 7 and the first wall portion 13 after being assembled according to still other embodiments of the present application. The distance between the first side surface 711 and the second side surface 1311b along the first direction gradually decreases along the depth direction of the first groove 131.

[0191] The depth direction of the first groove 131 is a direction from the groove opening of the first groove 131 to the first groove bottom surface 1312 of the first groove 131 . The depth direction of the first groove 131 may be parallel to the thickness direction Z of the first wall portion 13 .

[0192] It can be understood that the gap 8 formed between the first side surface 711 and the second side surface 1311b in the first direction gradually decreases along the depth direction of the first groove 131, and the distance at the narrowest position between the first side surface 711 and the second side surface 1311b can be equal to zero or greater than zero.

[0193] When the first wall portion 13 is deformed, the closer the second side surface 1311b is to the bottom surface 1312 of the first groove, the smaller the deformation is, and the smaller the extrusion effect on the first side surface 711 is; the closer the second side surface 1311b is to the notch of the first groove 131, the greater the deformation is, and the greater the extrusion effect on the first side surface 711 is. Gradually reducing the distance between the first side surface 711 and the second side surface 1311b along the first direction along the depth direction of the first groove 131 can reduce the extrusion effect of the second side surface 1311b on the first side surface 711 when the first wall portion 13 is deformed, and can reduce the range of movement of the pressure relief component 7 in the first groove 131 along the first direction when installing, thereby reducing the difficulty of installing the pressure relief component 7 and improving the installation accuracy of the pressure relief component 7.

[0194] In some embodiments, referring to FIG. 12 , the second side surface 1311 b is an inclined surface that forms a non-zero angle with the thickness direction Z of the first wall portion 13 .

[0195] The angle formed between the second side surface 1311 b and the thickness direction Z of the first wall portion 13 is a, and 0°<a≤90°.

[0196] As an example, the first groove bottom surface 1312 is a plane, the second side surface 1311b is set at an obtuse angle to the first groove bottom surface 1312 (shown in Figure 7), and the gap 8 along the first direction between the connection position of the first side surface 711 and the first groove bottom surface 1312 and the second side surface 1311b is the smallest.

[0197] As an example, the groove side surface 1311 (shown in FIG. 7 ) includes two second side surfaces 1311b and two third side surfaces 1311c (shown in FIG. 9 ). One second side surface 1311b, one third side surface 1311c, another second side surface 1311b, and another third side surface 1311c are sequentially connected end to end to form a closed structure. The third side surface 1311c forms a non-zero angle with the thickness direction Z of the first wall portion 13, forms an obtuse angle with the first groove bottom surface 1312, and is a conical surface.

[0198] In this embodiment, by setting the second side surface 1311b as a slope, it is beneficial to achieve that the distance between the first side surface 711 and the second side surface 1311b along the first direction gradually decreases along the depth direction of the first groove 131. During assembly, the inclined second side surface 1311b can play a role in guiding the pressure relief component 7, making it easier for the pressure relief component 7 to enter the first groove 131.

[0199] In some embodiments, referring to FIG. 13 , at least a portion of the longitudinal section of the second side surface 1311 b is arc-shaped, and the longitudinal section of the second side surface 1311 b is parallel to the first direction and the thickness direction Z of the first wall portion 13 .

[0200] The longitudinal section of the second side surface 1311 b may be arc-shaped as a whole, or only a portion thereof may be arc-shaped.

[0201] As an example, the second side surface 1311b is an arc surface, and the extension direction of the center line of the second side surface 1311b, the first direction, and the thickness direction Z of the first wall portion 13 are perpendicular to each other. The center of the longitudinal section of the second side surface 1311b is located at the center line of the second side surface 1311b. The gap 8 along the first direction between the connection position of the first side surface 711 and the first groove bottom surface 1312 (shown in Figure 7) and the second side surface 1311b is the smallest. Among them, the extension direction of the center line of the second side surface 1311b can be parallel to the width direction Y of the first wall portion 13, and the first direction can be parallel to the length direction X of the first wall portion 13.

[0202] As an example, the groove side surface 1311 includes two second side surfaces 1311b and two third side surfaces 1311c (shown in FIG9 ). One second side surface 1311b, one third side surface 1311c, another second side surface 1311b, and another third side surface 1311c are connected end to end to form a closed structure. Along the circumference of the first groove 131, the third side surface 1311c extends in an arc direction. The cross-sectional and longitudinal cross-sectional shapes of the third side surface 1311c are both arc-shaped, wherein the longitudinal cross-sectional shape of the third side surface 1311c is perpendicular to the extension direction of the third side surface 1311c; the cross-sectional shape of the third side surface 1311c is parallel to the first direction and perpendicular to the thickness direction Z of the first wall portion 13.

[0203] In this embodiment, at least a portion of the longitudinal cross-section of the second side surface 1311b is arc-shaped, which is conducive to achieving a gradual decrease in the distance between the first side surface 711 and the second side surface 1311b along the first direction along the depth direction of the first groove 131. During assembly, the second side surface 1311b can play a role in guiding the pressure relief component 7, facilitating the pressure relief component 7 to enter the first groove 131.

[0204] In some embodiments, referring to FIG. 11 to FIG. 13 , the first side surface 711 is parallel to the thickness direction Z of the first wall portion 13 .

[0205] As an example, the first side surface 711 is a plane perpendicular to the first groove bottom surface 1312 of the first groove 131 .

[0206] As an example, the surface of the pressure relief component 7 facing the third side surface 1311 c is parallel to the thickness direction Z of the first wall portion 13 .

[0207] In this embodiment, the first side surface 711 is parallel to the thickness direction Z of the first wall portion 13 , which can simplify the structure of the pressure relief component 7 and help reduce the difficulty of forming the pressure relief component 7 .

[0208] Continuing with reference to Figures 11-13 , in some embodiments, the pressure relief component 7 has a weak portion 73 configured to rupture to release the internal pressure of the battery cell 10. The pressure relief component 7 is welded to the bottom wall 1313 of the first groove 131 and forms a weld mark 133. Along the first direction, the weld mark 133 is at least partially located between the first side surface 711 and the weak portion 73. The maximum distance between the first side surface 711 and the second side surface 1311b is B1, the minimum distance between the weld mark 133 and the first side surface 711 is B2, and the minimum distance between the weld mark 133 and the weak portion 73 is B3, satisfying the following: 0.3≤(B1+B2) / B3≤2.5.

[0209] The weak portion 73 is a portion of the pressure relief component 7 that is weaker than other areas. This weak portion 73 can be a weakened portion of the pressure relief component 7. For example, the component 7 can be partially annealed to reduce the strength of that area, thereby forming the weak portion 73. Alternatively, a groove can be provided in the pressure relief component 7 to form a weak area in the area of ​​the groove. In the event of thermal runaway of the battery cell 10, the pressure relief component 7 can rupture at the weak portion 73, opening the pressure relief component 7 and releasing the pressure within the battery cell 10.

[0210] As an example, the pressure relief component 7 is provided with a notched groove 74, and the pressure relief component 7 forms a weakened portion 73 in the area where the notched groove 74 is provided. Along the first direction, the minimum distance between the weld mark 133 and the weakened portion 73 can be the minimum distance between the weld mark 133 and the edge of the bottom surface of the notched groove 74. The notched groove 74 can extend along a closed trajectory, for example, an annular groove; or it can extend along a non-closed trajectory, for example, an arc-shaped groove, a U-shaped groove, an H-shaped groove, etc. In the embodiment shown in Figures 11-13, the notched groove 74 is an annular groove, and the weld mark 133 is disposed around the outside of the notched groove 74.

[0211] In order to reduce the processing depth of the notched groove 74, a recessed groove 75 can be provided on the pressure relief component 7, and the notched groove 74 is provided on the bottom surface of the recessed groove 75. The recessed groove 75 can be a polygonal groove, a circular groove, or the like.

[0212] Along the first direction, the distance between the two positions farthest apart from each other on the first side surface 711 and the second side surface 1311 b is the maximum distance between the first side surface 711 and the second side surface 1311 b .

[0213] As an example, along the thickness direction Z of the first wall portion 13, the first wall portion 13 has a first surface 134, and the first groove 131 is provided on the first surface 134. A groove side surface 1311 (shown in FIG. 7 ) connects the first surface 134 and the first groove bottom surface 1312 (shown in FIG. 7 ). The position where the first surface 134 and the groove side surface 1311 connect forms the notch of the first groove 131. The distance between the position where the second side surface 1311b connects to the first surface 134 and the first side surface 711 along the first direction can be the maximum distance between the first side surface 711 and the second side surface 1311b. Along the thickness direction Z of the first wall portion 13, the first surface 134 can face or face away from the interior of the housing 1.

[0214] Along the first direction, the distance between the two closest positions of the welding portion 133 and the first side surface 711 is the minimum distance between the welding portion 133 and the first side surface 711 .

[0215] In this embodiment, (B1+B2) / B3 can be any point value of 0.3mm, 0.5mm, 0.8mm, 1mm, 1.3mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.5mm, etc., or a range value between any two of them.

[0216] In some embodiments, 0.8≤(B1+B2) / B3≤1.5.

[0217] In this embodiment, (B1+B2) / B3 can be any point value of 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, etc., or a range value between any two of them.

[0218] In some embodiments, 0.05 mm ≤ B1 ≤ 20 mm.

[0219] In this embodiment, B1 can be any point value of 0.05mm, 0.1mm, 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, etc., or a range value between any two of them.

[0220] B1≥0.05mm, so that the distance between the first side surface 711 and the second side surface 1311b is larger, reducing the extrusion effect of the second side surface 1311b on the first side surface 711 when the first wall portion 13 is deformed; B1≤20mm, so that the distance between the first side surface 711 and the second side surface 1311b is not too large, reducing the size of the first groove 131 in the first direction, and reducing the difficulty of forming the first groove 131.

[0221] In some embodiments, 1.5 mm ≤ B1 ≤ 10 mm.

[0222] In this embodiment, B1 can be any one of the point values ​​of 1.5mm, 1.8mm, 2mm, 2.3mm, 2.5mm, 2.8mm, 3mm, 3.3mm, 3.5mm, 3.8mm, 4mm, 4.3mm, 4.5mm, 4.8mm, 5mm, 5.3mm, 5.5mm, 5.8mm, 6mm, 6.3mm, 6.5mm, 6.8mm, 7mm, 7.3mm, 7.5mm, 7.8mm, 8mm, 8.3mm, 8.5mm, 8.8mm, 9mm, 9.3mm, 9.5mm, 9.8mm, 10mm, etc., or a range value between any two of them.

[0223] In some embodiments, 0.1 mm ≤ B2 ≤ 20 mm.

[0224] In this embodiment, B2 can be any point value of 0.1mm, 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, etc., or a range value between any two of them.

[0225] In this embodiment, B2 ≥ 0.1 mm, so that the distance between the weld mark 133 and the first side surface 711 is not too small, thereby reducing the risk of deformation of the area near the first side surface 711 during welding of the pressure relief component 7, thereby reducing the risk of the gap 8 becoming smaller; B2 ≤ 20 mm, so that the distance between the weld mark 133 and the first side surface 711 is not too large, and the pressure relief component 7 does not need to be made too large, which is conducive to miniaturization of the pressure relief component 7.

[0226] In some embodiments, 2 mm ≤ B2 ≤ 10 mm

[0227] In this embodiment, B2 can be any one of the point values ​​of 2mm, 2.3mm, 2.5mm, 2.8mm, 3mm, 3.3mm, 3.5mm, 3.8mm, 4mm, 4.3mm, 4.5mm, 4.8mm, 5mm, 5.3mm, 5.5mm, 5.8mm, 6mm, 6.3mm, 6.5mm, 6.8mm, 7mm, 7.3mm, 7.5mm, 7.8mm, 8mm, 8.3mm, 8.5mm, 8.8mm, 9mm, 9.3mm, 9.5mm, 9.8mm, 10mm, etc., or a range value between any two of them.

[0228] In some embodiments, 1 mm ≤ B3 ≤ 20 mm.

[0229] In this embodiment, B3 can be any point value of 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, etc., or a range value between any two of them.

[0230] In this embodiment, B3 ≥ 1 mm, so that there is a sufficient distance between the weld stamp 133 and the weak portion 73. The influence of the weld stamp 133 on the weak portion 73 is reduced, thereby reducing the impact of the distance between the weld stamp 133 and the weak portion 73 on the bursting pressure of the pressure relief component 7. B3 ≤ 20 mm, so that the distance between the weld stamp 133 and the weak portion 73 is not too large, which is conducive to miniaturization of the pressure relief component 7.

[0231] In some embodiments, 3 mm ≤ B3 ≤ 10 mm.

[0232] In this embodiment, B3 can be any one of the point values ​​of 3mm, 3.3mm, 3.5mm, 3.8mm, 4mm, 4.3mm, 4.5mm, 4.8mm, 5mm, 5.3mm, 5.5mm, 5.8mm, 6mm, 6.3mm, 6.5mm, 6.8mm, 7mm, 7.3mm, 7.5mm, 7.8mm, 8mm, 8.3mm, 8.5mm, 8.8mm, 9mm, 9.3mm, 9.5mm, 9.8mm, 10mm, etc., or a range value between any two of them.

[0233] In some embodiments, please continue to refer to FIG. 11 to FIG. 13 , the first wall portion 13 is a rectangular wall portion, and the first direction is parallel to the length direction X of the first wall portion 13 .

[0234] The first wall portion 13 is substantially in the shape of a rectangle when viewed along the thickness direction Z of the first wall portion 13. Two adjacent sides of the rectangle may be connected directly or through rounded corners.

[0235] The length direction X of the first wall portion 13 , the width direction Y of the first wall portion 13 , and the thickness direction Z of the first wall portion 13 are perpendicular to each other.

[0236] In this embodiment, since the first direction is parallel to the longitudinal direction X of the first wall portion 13, a gap 8 is formed between the first side surface 711 and the second side surface 1311b in the longitudinal direction X of the first wall portion 13. That is, a gap 8 is formed between the pressure relief component 7 and the groove side surface 1311 of the first groove 131 along the longitudinal direction X of the first wall portion 13. Since the first wall portion 13 is a rectangular wall portion, when the battery cell 10 expands, the phase change amount of the first wall portion 13 along the longitudinal direction X is greater. This gap 8 can provide a buffer space for the pressure relief component 7 along the longitudinal direction X of the first wall portion 13, thereby reducing the risk of the groove side surface 1311 squeezing the pressure relief component 7 along the longitudinal direction X of the first wall portion 13 and causing deformation of the pressure relief component 7.

[0237] In some embodiments, please refer to Figure 14, which is a partial enlarged view of the battery cell 10 at point A shown in Figure 4. Along the thickness direction Z of the first wall 13, the pressure relief component 7 is located on the side of the pressure relief hole 132 facing away from the interior of the housing 1 (not shown in Figure 14).

[0238] It is understood that, along the thickness direction Z of the first wall portion 13, the pressure relief component 7 is located on the side of the pressure relief hole 132 away from the electrode assembly 2. The side of the pressure relief hole 132 away from the interior of the housing 1 is the side of the pressure relief hole 132 facing the exterior of the housing 1.

[0239] In this embodiment, the pressure relief component 7 is located on the side of the pressure relief hole 132 away from the interior of the housing 1. The pressure relief component 7 can be installed on the outside of the first wall portion 13, making it more convenient to install the pressure relief component 7.

[0240] In some embodiments, please refer to Figure 15 , which is an isometric view of a battery cell 10 (both the pressure relief component 7 and the protective member 9 are separated from the first wall portion 13) provided in other embodiments of the present application. The battery cell 10 also includes a protective member 9 , which is located along the thickness direction Z of the first wall portion 13 on the side of the pressure relief component 7 facing away from the interior of the housing 1 , and covers the first groove 131 .

[0241] Along the thickness direction Z of the first wall portion 13, the side of the pressure relief component 7 that faces away from the interior of the housing 1 is the outside of the pressure relief component 7. The protective member 9 covers the first groove 131, so that the notch of the first groove 131 is blocked by the protective member 9. Along the thickness direction Z of the first wall portion 13, the projection of the notch of the first groove 131 is entirely located on the protective member 9. The protective member 9 can be a flat plate structure. The protective member 9 can be made of metal, such as copper, iron, aluminum, steel, etc. The protective member 9 can also be made of non-metallic materials, such as plastic, rubber, etc. The protective member 9 is fixed to the first wall portion 13. The protective member 9 can be fixed to the first wall portion 13 by welding, bonding, etc.

[0242] In this embodiment, the protective member 9 can protect the pressure relief component 7 and reduce the risk of external substances (impurities, electrolyte) entering the first groove 131 and corroding the pressure relief component 7.

[0243] In some embodiments, referring to Figures 16-18 , Figure 16 is a partial view of a battery cell 10 provided in some embodiments of the present application; Figure 17 is a partial view of a battery cell 10 provided in other embodiments of the present application; and Figure 18 is a partial view of a battery cell 10 provided in yet other embodiments of the present application. Along the thickness direction Z of the first wall portion 13 , the first wall portion 13 has an outer surface 135 facing away from the interior of the housing 1 . The outer surface 135 is provided with a second groove 136 . The first groove 131 is provided at the bottom surface of the second groove 136 , and the protective member 9 is at least partially accommodated in the second groove 136 .

[0244] The outer surface 135 of the first wall portion 13 may be the surface of the first wall portion 13 that is farthest from the electrode assembly 2 along the thickness direction Z. The bottom surface of the second groove 136 may be the first surface 134. The first groove 131 is disposed on the first surface 134. The protective member 9 may abut against the first surface 134 so that the protective member 9 covers the first groove 131. The second groove 136 may be a polygonal groove, a circular groove, or the like. The protective member 9 may be partially or completely contained within the second groove 136.

[0245] In this embodiment, the first wall portion 13 is provided with a second groove 136, and the protective member 9 is at least partially located in the second groove 136, which can reduce the height of the protective member 9 protruding from the outer surface 135 of the first wall portion 13 and reduce the space occupied by the protective member 9 outside the shell 1.

[0246] In some embodiments, referring to Figures 19 and 20 , Figure 19 is an exploded view of a battery cell 10 provided in another embodiment of the present application; and Figure 20 is a cross-sectional view of the battery cell 10 shown in Figure 19 . Along the thickness direction Z of the first wall portion 13 , the pressure relief component 7 is located on the side of the pressure relief hole 132 facing the interior of the housing 1 .

[0247] It can be understood that, along the thickness direction Z of the first wall portion 13 , the pressure relief component 7 is located on the side of the pressure relief hole 132 facing the electrode assembly 2 .

[0248] In this embodiment, the pressure relief component 7 is located on the side of the pressure relief hole 132 facing the interior of the shell 1. The pressure relief component 7 can be installed on the inner side of the first wall portion 13. The first wall portion 13 can protect the pressure relief component 7 and reduce the risk of the first wall portion 13 being damaged by external components.

[0249] In some embodiments, please refer to Figures 21-23. Figure 21 is a partial enlarged view of the battery cell 10 at point B shown in Figure 20. Figure 22 is a partial view of the assembled pressure relief component 7, protective member 9, and first wall portion 13 provided in some other embodiments of the present application. Figure 23 is a partial view of the assembled pressure relief component 7, protective member 9, and first wall portion 13 provided in some other embodiments of the present application. The battery cell 10 also includes a protective member 9. Along the thickness direction Z of the first wall portion 13, the protective member 9 is located on the side of the pressure relief hole 132 facing away from the interior of the housing 1 (shown in Figure 20). The protective member 9 covers the pressure relief hole 132.

[0250] Along the thickness direction Z of the first wall portion 13, the side of the pressure relief hole 132 facing away from the interior of the housing 1 is the side of the pressure relief hole 132 facing the exterior of the housing 1. Along the thickness direction Z of the first wall portion 13, the pressure relief component 7 and the protective member 9 are respectively located on either side of the pressure relief hole 132, with the pressure relief component 7 being located on the side of the pressure relief hole 132 facing the interior of the housing 1, and the protective member 9 being located on the side of the pressure relief hole 132 facing away from the interior of the housing 1.

[0251] The protective member 9 covers the pressure relief hole 132 , and the protective member 9 blocks the pressure relief hole 132 . Along the thickness direction Z of the first wall portion 13 , the projection of the hole wall surface of the pressure relief hole 132 can be entirely located on the protective member 9 .

[0252] As an example, along the thickness direction Z of the first wall portion 13 , a protrusion 137 arranged around the pressure relief hole 132 is formed on the side of the first wall portion 13 facing away from the interior of the housing 1 , and the protective member 9 is fixed to the protrusion 137 to cover the pressure relief hole 132 .

[0253] In this embodiment, the protective member 9 can protect the pressure relief component 7 and reduce the risk of external substances (impurities, electrolyte) entering the pressure relief hole 132 and corroding the pressure relief component 7.

[0254] In some embodiments, the housing 1 includes a housing 11 and an end cap 12 . The housing 11 has an opening, and the end cap 12 closes the opening. The end cap 12 is a first wall 13 ; and / or at least one wall of the housing 11 is a first wall 13 .

[0255] In the embodiment where the end cap 12 serves as the first wall portion 13, if only one end cap 12 is provided in the housing 1, the end cap 12 serves as the first wall portion 13; if two end caps 12 are provided in the housing 1, either one end cap 12 or both end caps 12 may serve as the first wall portion 13. As an example, in the embodiment of Figures 19 to 23, the housing 11 is a hollow structure with an opening formed at one end, and there is only one end cap 12, which serves as the first wall portion 13.

[0256] In embodiments where at least one wall portion of the housing 11 is the first wall portion 13, one wall portion of the housing 11 may be the first wall portion 13, or multiple walls of the housing 11 may be the first wall portion 13. In some embodiments, the housing 11 is a hollow structure with an opening formed at one end, and the wall portion of the housing 11 opposite the end cap 12 serves as the first wall portion 13. In other embodiments, please refer to Figures 24 and 25. Figure 24 is an exploded view of a battery cell 10 provided in still other embodiments of the present application; Figure 25 is a cross-sectional view of the battery cell 10 shown in Figure 24. The housing 11 is a hollow structure with openings formed at opposite ends. There are two end caps 12, and both end caps 12 are provided with electrode terminals 3. Tabs 21 are formed at opposite ends of the electrode assembly 2. The electrode terminal 3 on one end cap 12 is electrically connected to the tab 21 at one end of the electrode assembly 2, and the electrode terminal on the other end cap 12 is electrically connected to the tab 21 at the other end of the electrode assembly 2. One wall portion in the shell 11 is a first wall portion 13 , and the first wall portion 13 supports the electrode assembly 2 along the direction of gravity.

[0257] An embodiment of the present application provides a battery 100 , comprising the battery cell 10 provided in any one of the above embodiments.

[0258] An embodiment of the present application provides an electrical device, comprising the battery cell 10 provided in any one of the above embodiments.

[0259] The embodiment of the present application also provides a battery cell 10, which includes a shell 1, an electrode assembly 2, a pressure relief component 7 and a protective member 9. The electrode assembly 2 is accommodated in the shell 1. The shell 1 includes a shell body 11 and an end cover 12. An opening is formed at one end of the shell body 11, and the end cover 12 closes the opening of the shell body 11. The wall portion of the shell body 11 opposite to the end cover 12 is a first wall portion 13. Along the thickness direction Z of the first wall portion 13, the first wall portion 13 has an outer surface 135 facing away from the interior of the shell body 1. The outer surface 135 is provided with a second groove 136. The groove bottom surface of the second groove 136 is provided with a first groove 131. The first groove 131 includes a groove side surface 1311 and a first groove bottom surface 1312. The groove side surface 1311 is arranged around the first groove bottom surface 1312. The first groove bottom surface 1312 is provided with a pressure relief hole 132. The pressure relief component 7 is disposed within the first groove 131, resting against the first groove bottom surface 1312 and covering the pressure relief hole 132. Along the thickness direction Z of the first wall portion 13, the pressure relief component 7 is located on the side of the pressure relief hole 132 facing away from the electrode assembly 2. A gap 8 is formed between the groove side surface 1311 and the pressure relief component 7 along the entire circumference of the first groove 131. A protective member 9 is disposed within the second groove 136 and covers the first groove 131.

[0260] The pressure relief component 7 includes a first welded area 72, and the groove bottom wall 1313 includes a second welded area 1313a. The second welded area 1313a defines the pressure relief hole 132. The first welded area 72 and the second welded area 1313a overlap along the thickness direction Z of the first wall portion 13. The first welded area 72 and the second welded area 1313a are welded together to form the welded portion 133. Along the thickness direction Z of the first wall portion 13, the projection of the welded portion 133 is entirely located on the pressure relief component 7. The minimum thickness of the first welded area 72 is H1, the minimum thickness of the second welded area 1313a is H2, and the maximum height of the welded portion 133 is H3. The following conditions are met: H1 < H3 ≤ H1 + H2, 0.2 mm ≤ H1 ≤ 1 mm, and 0.2 mm ≤ H2 ≤ 5 mm.

[0261] The first wall portion 13 is a rectangular wall portion. The pressure relief component 7 has first side surfaces 711 formed at opposite ends along the length direction X of the first wall portion 13. The groove side surfaces 1311 include second side surfaces 1311b facing the first side surfaces 711. The second side surfaces 1311b correspond one-to-one with the first side surfaces 711, and a gap 8 is formed between the first side surfaces 711 and the second side surfaces 1311b. The length direction X of the first wall portion 13 is perpendicular to the thickness direction Z of the first wall portion 13, and the first side surfaces 711 are parallel to the thickness direction Z of the first wall portion 13. The second side surfaces 1311b are parallel to the thickness direction Z of the first wall portion 13; alternatively, the second side surfaces 1311b are inclined surfaces arranged at a non-zero angle with the thickness direction Z of the first wall portion 13; alternatively, the second side surfaces 1311b have an arc-shaped longitudinal cross-section, and the longitudinal cross-sections of the second side surfaces 1311b are parallel to both the length direction X and the thickness direction Z of the first wall portion 13. The pressure relief component 7 has a weak portion 73. Both the weak portion 73 and the welded portion 133 are annular. The welded portion 133 surrounds the outside of the weak portion 73, and the outer peripheral surface 71 of the pressure relief component 7 surrounds the outside of the weak portion 73. Along the length direction X of the first wall portion 13, the maximum distance between the first side surface 711 and the second side surface 1311b is B1, the minimum distance between the welded portion 133 and the first side surface 711 is B2, the minimum distance between the welded portion 133 and the weak portion 73 is B3, and the minimum distance between the welded portion 133 and the first side surface 711 is B2. 0.3 ≤ (B1 + B2) / B3 ≤ 2.5, 0.05 mm ≤ B1 ≤ 20 mm, 0.1 mm ≤ B2 ≤ 20 mm, and 1 mm ≤ B3 ≤ 20 mm.

[0262] The embodiment of the present application also provides a battery cell 10, which includes an outer shell 1, an electrode assembly 2, a pressure relief component 7 and a protective member 9. The electrode assembly 2 is accommodated in the outer shell 1. The outer shell 1 includes a shell body 11 and an end cover 12. An opening is formed at one end of the shell body 11, and the end cover 12 closes the opening of the shell body 11. The end cover 12 is a first wall portion 13. Along the thickness direction Z of the first wall portion 13, the first wall portion 13 has a first surface 134. The first surface 134 is the inner surface of the first wall portion 13. The first surface 134 is provided with a first groove 131. The first groove 131 includes a groove side surface 1311 and a first groove bottom surface 1312. The groove side surface 1311 is arranged around the first groove bottom surface 1312. The first groove bottom surface 1312 is provided with a pressure relief hole 132. The pressure relief component 7 is disposed within the first groove 131, abutting against the first groove bottom surface 1312 and covering the pressure relief hole 132. Along the thickness direction Z of the first wall portion 13, the pressure relief component 7 is located on the side of the pressure relief hole 132 facing the electrode assembly 2. A gap 8 is formed between the groove side surface 1311 and the pressure relief component 7 along the entire circumference of the first groove 131. Along the thickness direction Z of the first wall portion 13, a protective member 9 is disposed on the side of the pressure relief hole 132 facing away from the electrode terminal 3, covering the first groove 131.

[0263] The pressure relief component 7 includes a first welded area 72, and the groove bottom wall 1313 includes a second welded area 1313a. The second welded area 1313a defines the pressure relief hole 132. The first welded area 72 and the second welded area 1313a overlap along the thickness direction Z of the first wall portion 13. The first welded area 72 and the second welded area 1313a are welded together to form the welded portion 133. Along the thickness direction Z of the first wall portion 13, the projection of the welded portion 133 is entirely located on the pressure relief component 7. The minimum thickness of the first welded area 72 is H1, the minimum thickness of the second welded area 1313a is H2, and the maximum height of the welded portion 133 is H3. The following conditions are met: H1 < H3 ≤ H1 + H2, 0.2 mm ≤ H1 ≤ 1 mm, and 0.2 mm ≤ H2 ≤ 5 mm.

[0264] The first wall portion 13 is a rectangular wall portion. The pressure relief component 7 has first side surfaces 711 formed at opposite ends along the length direction X of the first wall portion 13. The groove side surfaces 1311 include second side surfaces 1311b facing the first side surfaces 711. The second side surfaces 1311b correspond one-to-one with the first side surfaces 711, and a gap 8 is formed between the first side surfaces 711 and the second side surfaces 1311b. The length direction X of the first wall portion 13 is perpendicular to the thickness direction Z of the first wall portion 13, and the first side surfaces 711 are parallel to the thickness direction Z of the first wall portion 13. The second side surfaces 1311b are parallel to the thickness direction Z of the first wall portion 13; alternatively, the second side surfaces 1311b are inclined surfaces arranged at a non-zero angle with the thickness direction Z of the first wall portion 13; alternatively, the second side surfaces 1311b have an arc-shaped longitudinal cross-section, and the longitudinal cross-sections of the second side surfaces 1311b are parallel to both the length direction X and the thickness direction Z of the first wall portion 13. The pressure relief component 7 has a weak portion 73. Both the weak portion 73 and the welded portion 133 are annular. The welded portion 133 surrounds the outside of the weak portion 73, and the outer peripheral surface 71 of the pressure relief component 7 surrounds the outside of the weak portion 73. Along the length direction X of the first wall portion 13, the maximum distance between the first side surface 711 and the second side surface 1311b is B1, the minimum distance between the welded portion 133 and the first side surface 711 is B2, the minimum distance between the welded portion 133 and the weak portion 73 is B3, and the minimum distance between the welded portion 133 and the first side surface 711 is B2. 0.3 ≤ (B1 + B2) / B3 ≤ 2.5, 0.05 mm ≤ B1 ≤ 20 mm, 0.1 mm ≤ B2 ≤ 20 mm, and 1 mm ≤ B3 ≤ 20 mm.

[0265] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0266] The above embodiments are intended only to illustrate the technical solutions of this application and are not intended to limit this application. Those skilled in the art will appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application are intended to be within the scope of protection of this application.

Claims

1. A battery cell, comprising: The housing comprises a first wall portion, the first wall portion is provided with a first groove, the first groove comprises a groove side surface and a first groove bottom surface, the groove side surface is arranged around the first groove bottom surface, and the first groove bottom surface is provided with a pressure relief hole; A pressure relief component is disposed in the first groove, the pressure relief component abuts against the bottom surface of the first groove and covers the pressure relief hole; Wherein, a gap is formed between at least a portion of the groove side surface along the circumference of the first groove and the pressure relief component.

2. The battery cell according to claim 1, wherein: The groove side includes a first area with a gap formed with the pressure relief component; Along the circumference of the first groove, the length of the first area is L1, and the circumference of the groove side is L, satisfying: 0.2≤L1 / L≤1; optionally, 0.5≤L1 / L≤1.

3. The battery cell according to claim 1 or 2, wherein: A gap is formed between the groove side surface and the pressure relief component along the entire circumference of the first groove.

4. The battery cell according to any one of claims 1 to 3, wherein: The pressure relief component is welded to the bottom wall of the first groove and has a weld mark.

5. The battery cell according to claim 4, wherein: Along the thickness direction of the first wall portion, projections of the welded portions are all located on the pressure relief component.

6. The battery cell according to claim 5, wherein: The pressure relief component and the groove bottom wall have an overlapping area, the overlapping area includes a first welding area located on the pressure relief component and a second welding area located on the groove bottom wall, the second welding area defines the pressure relief hole, the first welding area and the second welding area are welded and connected to form the weld mark; Along the thickness direction of the first wall portion, the minimum thickness of the first welding area is H1, the minimum thickness of the second welding area is H2, and the maximum height of the weld mark is H3, satisfying: H1<H3≤H1+H2.

7. The battery cell according to claim 6, wherein: 0.2mm≤H1≤1mm; optionally, 0.45mm≤H1≤0.75mm.

8. The battery cell according to claim 6 or 7, wherein: 0.2mm≤H2≤5mm; optionally, 0.8mm≤H2≤3mm.

9. The battery cell according to any one of claims 1 to 8, wherein: Along a first direction, at least one end of the pressure relief component forms a first side surface, the groove side surface includes a second side surface facing the first side surface, a gap is formed between the first side surface and the second side surface, and the first direction intersects with a thickness direction of the first wall portion.

10. The battery cell according to claim 9, wherein: The first side surface is parallel to the second side surface.

11. The battery cell according to claim 9 or 10, wherein: The second side surface is parallel to a thickness direction of the first wall portion.

12. The battery cell according to claim 9, wherein: The distance between the first side surface and the second side surface along the first direction gradually decreases along the depth direction of the first groove.

13. The battery cell according to claim 12, wherein: The second side surface is an inclined surface that is arranged at a non-zero angle with the thickness direction of the first wall portion.

14. The battery cell according to claim 12, wherein: At least a portion of a longitudinal section of the second side surface is in an arc shape, and the longitudinal section is parallel to the first direction and a thickness direction of the first wall portion.

15. The battery cell according to any one of claims 9 to 14, wherein: The first side surface is parallel to a thickness direction of the first wall portion.

16. The battery cell according to any one of claims 9 to 15, wherein: The pressure relief component has a weak portion, and the weak portion is configured to be broken to release the internal pressure of the battery cell; The pressure relief component is welded to the bottom wall of the first groove and is formed with a weld mark. Along the first direction, the weld mark is at least partially located between the first side surface and the weak portion. The maximum distance between the first side surface and the second side surface is B1, the minimum distance between the weld mark and the first side surface is B2, and the minimum distance between the weld mark and the weak portion is B3, satisfying: 0.3≤(B1+B2) / B3≤2.5; optionally, 0.8≤(B1+B2) / B3≤1.

5.

17. The battery cell according to claim 16, wherein: 0.05mm≤B1≤20mm; optionally, 1.5mm≤B1≤10mm.

18. The battery cell according to claim 16 or 17, wherein: 0.1mm≤B2≤20mm; optionally, 2mm≤B2≤10mm.

19. The battery cell according to any one of claims 16 to 18, wherein: 1mm≤B3≤20mm; optionally, 3mm≤B3≤10mm.

20. The battery cell according to any one of claims 9 to 19, wherein: The first wall portion is a rectangular wall portion, and the first direction is parallel to a length direction of the first wall portion.

21. The battery cell according to any one of claims 1 to 20, wherein: Along the thickness direction of the first wall portion, the pressure relief component is located at a side of the pressure relief hole facing away from the interior of the housing.

22. The battery cell according to claim 21, wherein: The battery cell further includes a protection member, which is located at a side of the pressure relief component away from the interior of the housing along a thickness direction of the first wall portion, and covers the first groove.

23. The battery cell according to claim 22, wherein: Along the thickness direction of the first wall portion, the first wall portion has an outer surface facing away from the interior of the housing, the outer surface is provided with a second groove, the first groove is provided at the groove bottom surface of the second groove, and the protective member is at least partially accommodated in the second groove.

24. The battery cell according to any one of claims 1 to 20, wherein: Along the thickness direction of the first wall portion, the pressure relief component is located at a side of the pressure relief hole facing the interior of the housing.

25. The battery cell according to claim 24, wherein: The battery cell further includes a protective member, which is located on a side of the pressure relief hole away from the interior of the housing along a thickness direction of the first wall portion, and covers the pressure relief hole.

26. The battery cell according to any one of claims 1 to 25, wherein: The housing comprises: a housing having an opening; an end cap for closing the opening; Wherein, the end cover is the first wall portion; and / or, at least one wall portion of the shell is the first wall portion.

27. A battery comprising the battery cell according to any one of claims 1 to 26.

28. An electrical device comprising the battery cell according to any one of claims 1 to 26.

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