Shell component, battery cell, battery and electric equipment

Abstract

The embodiment of the invention provides a shell component, a battery monomer, a battery and electric equipment, and belongs to the technical field of batteries. The shell component comprises a first surface and a second surface, the first surface and the second surface are oppositely arranged in the first direction, and the shell component is provided with a first groove part sunken from the first surface in the direction close to the second surface. The shell part forms a weak area at the bottom of the first groove part, the weak area is configured to be damaged when the battery monomer releases internal pressure, and a convex part protruding out of the second surface is arranged on one side, deviating from the first groove part, of the weak area in the first direction. And the convex part has a reinforcing effect on the weak area, so that the fatigue resistance of the weak area can be improved, and the risk that the weak area is damaged in the normal use of the battery monomer is reduced, thereby prolonging the service life of the battery monomer.

Description

Shell parts, battery cells, batteries and electrical equipment Technical Field

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

[0002] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and power tools.

[0003] Typical battery cells are equipped with pressure relief mechanisms. In the event of thermal runaway, these mechanisms release internal pressure to improve reliability. Of course, in addition to improving reliability, the lifespan of battery cells is also a consideration. Therefore, increasing the lifespan of battery cells is a pressing issue in battery technology.

[0004] Summary of the Invention

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

[0006] In a first aspect, an embodiment of the present application provides a shell component for a battery cell, the shell component including a first surface and a second surface, the first surface and the second surface being arranged opposite to each other along a first direction, the shell component being provided with a first groove portion recessed from the first surface along a direction close to the second surface; the shell component forming a weak area at the bottom of the first groove portion, the weak area being configured to be destroyed when the battery cell releases internal pressure, and a convex portion protruding from the second surface being provided on a side of the weak area away from the first groove portion along the first direction.

[0007] In the above technical solution, a convex portion protruding from the second surface is provided on the side of the weak area away from the first groove portion. The convex portion strengthens the weak area, thereby improving the fatigue strength of the weak area and reducing the risk of the weak area being damaged during normal use of the battery cell, thereby increasing the service life of the battery cell.

[0008] In some embodiments, along the first direction, the first groove portion includes a first groove bottom surface located between the first surface and the second surface, the minimum distance between the first groove bottom surface and the second surface is D, the height of the protrusion protruding from the second surface is H, and 0.01≤H / (D+H)≤0.67. When H / (D+H)>0.67, the strength of the weak zone is too great, making it more difficult to destroy the weak zone during thermal runaway of the battery cell, which can lead to untimely pressure relief and a higher probability of battery cell explosion. When H / (D+H)<0.01, the protrusion's ability to reinforce the weak zone is insufficient, increasing the risk of the weak zone being destroyed during normal use of the battery cell. A value of 0.01≤H / (D+H)≤0.67 can further reduce the risk of the weak zone being destroyed during normal use of the battery cell, thereby extending the battery cell's service life, reducing the risk of battery cell explosion during thermal runaway, and improving the battery cell's reliability.

[0009] In some embodiments, 0.03≤H / (D+H)≤0.33. This improves the overall performance of the housing component, allowing the weak area to be destroyed in a timely manner when the battery cell experiences thermal runaway, and the weak area has sufficient fatigue resistance under normal use conditions of the battery cell, thereby increasing the service life of the battery cell.

[0010] In some embodiments, along the first direction, the height of the protrusion protruding from the second surface is H, and 0.01 mm ≤ H ≤ 0.96 mm. In this way, the protrusion can effectively strengthen the weak area without being too high, thereby reducing the space occupied by the protrusion outside or inside the battery cell.

[0011] In some embodiments, 0.05 mm ≤ H ≤ 0.55 mm, which further reduces the space occupied by the protrusion outside or inside the battery cell and enhances the reinforcing effect of the protrusion on the weak area.

[0012] In some embodiments, the first groove portion includes a first groove bottom surface and a first groove side surface connected to the first groove bottom surface. The first groove side surface forms an angle θ with the first groove bottom surface, measured in degrees. The first groove side surface is connected to the first groove bottom surface at a connection location. Along the first direction, the minimum residual thickness of the housing component at the connection location is L, measured in mm. 90 ≤ θ / L ≤ 5833. This can extend the service life of the battery cell, reduce the risk of explosion of the battery cell during thermal runaway, and improve the reliability of the battery cell.

[0013] In some embodiments, 220≤θ / L≤933. In this way, the service life of the battery cell can be further increased, and the reliability of the battery cell can be improved.

[0014] In some embodiments, 90°≤θ≤175°.

[0015] In some embodiments, 0.03 mm ≤ L ≤ 1 mm.

[0016] In some embodiments, along the first direction, the first groove portion includes a first groove bottom surface located between the first surface and the second surface; the outer surface of the protrusion is connected to the second surface to form a first contour line, and the projection of the first contour line along the first direction is located within the first groove bottom surface. This reduces the coverage of the protrusion over the weak area, making it easier to destroy the weak area during thermal runaway of the battery cell and timely release the pressure inside the battery cell.

[0017] In some embodiments, the projection of the first contour line along the first direction within the bottom surface of the first groove coincides with the edge line of the bottom surface of the first groove. This allows the protrusion to completely cover the weak area, effectively reinforcing the weak area, improving its fatigue resistance and reducing the risk of damage during normal battery cell use. Furthermore, the weak area is further weakened at the edge line of the bottom surface of the first groove, facilitating its destruction in the event of thermal runaway of the battery cell.

[0018] In some embodiments, the projection of the first contour line along the first direction within the bottom surface of the first groove does not contact the edge line of the bottom surface of the first groove. This creates an area of ​​the weak zone that is not covered by the protrusion. This area is thinner and more easily damaged in the event of thermal runaway of the battery cell, thereby improving the timeliness of the pressure relief of the battery cell.

[0019] In some embodiments, along a first direction, the first groove portion includes a first groove bottom surface located between the first surface and the second surface; the outer surface of the protrusion is connected to the second surface to form a first contour line, the first contour line defining a first region, and the projection of the edge line of the first groove bottom surface along the first direction is located within the first region and does not contact the first contour line. In this way, the protrusion completely covers the weak area, connecting both the protrusion to the weak area and to areas of the housing component other than the weak area, further enhancing the protrusion's reinforcement effect on the weak area and further improving the fatigue resistance of the weak area.

[0020] In some embodiments, the outer surface of the protrusion is connected to the second surface to form a first contour line. The first contour line defines a first region. The area of ​​the first region is S1. The area of ​​the portion of the projection of the first region along the first direction located within the first groove is S2. S2 / S1 ≥ 0.6. This allows a larger portion of the protrusion to cover the weak area, thereby enhancing the reinforcement effect of the protrusion on the weak area.

[0021] In some embodiments, along the first direction, the surface of the protrusion facing away from the second surface is a plane. This allows the thickness of the area of ​​the protrusion covered by the plane to be more uniform, thus uniformly reinforcing different areas of the weak zone. This structure makes the protrusion easier to shape.

[0022] In some embodiments, along the first direction, the surface of the convex portion facing away from the second surface is an arc-shaped surface, and the cross-section of the arc-shaped surface is an arc that bulges outward from the second surface at the center. This structure makes the cross-section of the convex portion generally arched, which has better deformation resistance and is less likely to damage the weak area when the convex portion is subjected to impact force.

[0023] In some embodiments, the extending direction of the protrusion is consistent with the extending direction of the first groove, so as to strengthen more areas of the weak zone and enhance the strengthening effect of the protrusion on the weak zone.

[0024] In some embodiments, the protrusion is integrally formed with the weak area, so that the protrusion has a better reinforcement effect on the weak area.

[0025] In some embodiments, the first groove is stamped and formed on the housing component. When the first groove is stamped and formed on the housing component, a convex portion protruding from the second surface can be formed at a position corresponding to the first groove, thereby achieving integral formation of the convex portion and the weak area.

[0026] In some embodiments, the first groove defines a pressure relief zone, and the first groove is arranged along the edge of the pressure relief zone. During pressure relief, the pressure relief zone can be opened with the first groove as the boundary, thereby increasing the pressure relief area of ​​the housing component and improving the timeliness of pressure relief.

[0027] In some embodiments, the first groove portion includes a first groove section and a second groove section, the first groove section and the second groove section intersecting each other, and the first groove section and the second groove section are arranged along the edge of the pressure relief zone. The stress at the intersection of the first and second groove sections is more concentrated, making the weak zone at the intersection of the first and second groove sections more easily destroyed, thereby improving the pressure relief sensitivity of the housing component and promptly releasing pressure when the internal pressure of the battery cell reaches the detonation pressure. If the detonation pressure of the battery cell is constant, the weak zone can be made thicker, reducing the molding depth of the first groove portion.

[0028] In some embodiments, the first slot portion further includes a third slot section, the first slot section and the third slot section are arranged opposite each other, the third slot section intersects with the second slot section, and the first slot section, the second slot section, and the third slot section are arranged along the edge of the pressure relief zone. In this way, the pressure relief zone can be opened with the first slot section, the second slot section, and the third slot section as boundaries, and large-area pressure relief can be achieved. In addition, the intersection of the third slot section and the second slot section is more concentrated, making it easier to destroy the weak area at the intersection of the third slot section and the second slot section, thereby improving the pressure relief sensitivity of the shell component and timely releasing the pressure when the internal pressure of the battery cell reaches the detonation pressure.

[0029] In some embodiments, the first slot section, the second slot section and the third slot section are connected in sequence. Such a first slot section has a simple structure and is easy to form.

[0030] In some embodiments, the first slot segment intersects with the second slot segment at a first position offset from the ends of the first slot segment in its extension direction; the third slot segment intersects with the second slot segment at a second position offset from the ends of the third slot segment in its extension direction. This structure defines two pressure relief zones in the first slot portion, one located on either side of the second slot segment. The two pressure relief zones can be opened in a split manner to relieve pressure, effectively improving the pressure relief efficiency of the housing component.

[0031] In some embodiments, the first position is located at the midpoint of the first slot segment in the extension direction, and the second position is located at the midpoint of the third slot segment in the extension direction. In this way, the weak areas at the first and second positions are more easily destroyed, thereby improving the pressure relief sensitivity of the housing component and improving the timeliness of pressure relief.

[0032] In some embodiments, the first groove portion is a groove extending along a non-closed trajectory. The pressure relief area defined by the first groove portion can be opened in a flipping manner. After opening, the pressure relief area can eventually connect to other areas of the housing component, reducing the risk of splashing after the pressure relief area is opened.

[0033] In some embodiments, the first groove portion is an arc-shaped groove. The arc-shaped groove has a simple structure and is easy to form. During the pressure relief process, the pressure relief area can quickly rupture along the arc-shaped groove, so that the pressure relief area can be quickly opened.

[0034] In some embodiments, the first groove portion is a groove extending along a closed trajectory. During the pressure relief process, the housing component can rupture along the first groove portion, so that the pressure relief area can be opened in a detachable manner, thereby increasing the pressure relief area of ​​the housing component and improving the pressure relief rate of the housing component.

[0035] In some embodiments, the first groove is an annular groove. The annular groove has a simple structure and is easy to form. During the pressure relief process, the shell component can be quickly ruptured along the annular groove to quickly open the pressure relief area.

[0036] In some embodiments, the housing component is provided with a second groove portion, which is arranged in a direction from the first surface to the second surface. The second groove portion and the first groove portion are arranged sequentially, and the bottom surface of the second groove portion forms the first surface. During molding, the second groove portion can be molded into the housing component first, and then the first groove portion can be molded into the housing component to form a weak zone. In other words, forming the weak zone after forming at least two levels of grooves in the housing component can reduce the molding depth of each level of grooves, thereby reducing the molding force applied to the housing component during molding and reducing the risk of cracks in the housing component.

[0037] In some embodiments, the first groove portion and the pressure relief zone are both located on the groove bottom wall of the second groove portion. When the pressure relief zone opens into the second groove portion, the second groove portion can provide an escape space for the pressure relief zone.

[0038] In some embodiments, the cross section of the second groove portion perpendicular to the first direction is polygonal or circular. The second groove portion of this structure is simple in structure and easy to form, and can provide more avoidance space for the pressure relief area during the opening process.

[0039] In some embodiments, the second groove extends in the same direction as the first groove. The shape of the second groove is substantially the same as the shape of the first groove, facilitating the formation of the second groove. When the first and second grooves are formed by stamping, the amount of material extruded during the formation of the second groove can be reduced, thereby reducing the forming force on the housing component.

[0040] In some embodiments, the shell component is provided with a third groove portion, and the second groove portion is provided on the bottom surface of the third groove portion; the first groove portion, the second groove portion, and the pressure relief zone are all located on the bottom wall of the third groove portion. During molding, the third groove portion can be molded on the shell component first, then the second groove portion can be molded on the shell component, and then the first groove portion can be molded on the shell component to form a weak zone. In other words, after forming at least three levels of groove portions on the shell component to form a weak zone, the molding depth of each level of groove portion can be reduced, thereby reducing the molding force on the shell component during molding and reducing the risk of cracks in the shell component. In addition, since the pressure relief zone is located on the bottom wall of the third groove portion, when the pressure relief zone opens into the third groove portion, the third groove portion can provide an escape space for the pressure relief zone.

[0041] In some embodiments, the cross section of the third groove portion perpendicular to the first direction is polygonal or circular. The third groove portion of this structure is simple in structure and easy to form, and can provide more avoidance space for the pressure relief area during the opening process.

[0042] In some embodiments, the housing component is an end cap, which is used to seal the opening of the housing, which is used to accommodate the electrode assembly. This provides a pressure relief function for the end cap, improving the reliability of the battery cell. Furthermore, as a housing component, the end cap makes it easier to form weak areas on the end cap.

[0043] In some embodiments, the second surface is the surface of the end cap facing the interior of the housing. In this way, the protrusion protruding from the second surface is located inside the housing, effectively utilizing the interior space of the housing.

[0044] In some embodiments, the housing component is a shell having an opening for accommodating the electrode assembly. The shell has a pressure relief function, so that the battery cell has good reliability.

[0045] In some embodiments, the housing includes multiple integrally formed walls that collectively define an interior space of the housing, and at least one of the walls has a weakened area. The integrally formed walls provide the housing with excellent structural stability, and the walls are not easily damaged when the weakened area is formed.

[0046] In some embodiments, the multiple wall portions include a bottom wall and multiple side walls surrounding the bottom wall. The housing has an opening at one end opposite the bottom wall. The bottom wall has a weakened area. And / or at least one of the side walls has a weakened area. If the bottom wall of the housing has a weakened area, the battery cells can release pressure through the bottom wall. If at least one of the side walls has a weakened area, the battery cells can release pressure through the side walls.

[0047] In some embodiments, the second surface is the surface of the wall portion provided with the weak area facing the interior of the housing. In this way, the protrusion protruding from the second surface is located inside the housing, effectively utilizing the interior space of the housing.

[0048] In some embodiments, the housing is a rectangular parallelepiped, which is suitable for rectangular parallelepiped battery cells and can meet the large capacity requirements of battery cells.

[0049] In some embodiments, the material of the housing component includes aluminum alloy. The housing component made of aluminum alloy is light in weight, has good ductility, and is easy to form.

[0050] In a second aspect, an embodiment of the present application provides a battery cell, comprising the housing component provided in any one embodiment of the first aspect.

[0051] In some embodiments, the battery cell further includes a shell having an opening, and the shell is used to accommodate the electrode assembly; the outer shell component is an end cover, and the end cover closes the opening.

[0052] In some embodiments, the housing component is a shell having an opening, and the shell is used to accommodate the electrode assembly; the battery cell further includes an end cover, which closes the opening.

[0053] In a third aspect, an embodiment of the present application provides a battery, comprising a battery cell provided by any embodiment of the second aspect.

[0054] In a fourth aspect, an embodiment of the present application provides an electrical device, comprising a battery cell provided by any one embodiment of the second aspect, wherein the battery cell is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] 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.

[0056] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0057] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0058] FIG3 is an exploded view of a battery cell provided in some embodiments of the present application;

[0059] FIG4 is a schematic structural diagram of a housing component provided in some embodiments of the present application;

[0060] FIG5 is a cross-sectional view taken along line AA of the housing member shown in FIG4 ;

[0061] FIG6 is a partial enlarged view of the housing component (the bottom surface of the first groove is a flat surface) at B shown in FIG5 ;

[0062] FIG7 is a partial enlarged view of a housing component (the bottom surface of the first groove is an arc surface) provided in some embodiments of the present application;

[0063] FIG8 is a C-direction view of the housing component shown in FIG6;

[0064] FIG9 is a view of the housing member shown in FIG6 taken along the direction E;

[0065] FIG10 is a partial enlarged view of a housing component provided in some embodiments of the present application (the projection of the first contour line within the bottom surface of the first groove does not contact the edge line of the bottom surface of the first groove);

[0066] FIG11 is a partial enlarged view of a housing component provided in some other embodiments of the present application (the projection of the first contour line within the bottom surface of the first groove does not contact the edge line of the bottom surface of the first groove);

[0067] FIG12 is a view of the housing member shown in FIG10 taken along the arrow F;

[0068] FIG13 is a partial enlarged view of an external component provided in some embodiments of the present application (the projection of the edge line of the bottom surface of the first groove along the first direction is located within the first region and does not contact the first contour line);

[0069] FIG14 is a G-direction view of the housing member shown in FIG13;

[0070] FIG15 is a partial enlarged view of an external component provided in some other embodiments of the present application (the projection of the edge line of the bottom surface of the first groove along the first direction is located within the first region and does not contact the first contour line);

[0071] FIG16 is a partial enlarged view of an external component provided in some further embodiments of the present application (the projection of the edge line of the bottom surface of the first groove along the first direction is located within the first region and does not contact the first contour line);

[0072] FIG17 is a view of the housing component shown in FIG16 (showing the first area) taken along arrow I;

[0073] 18 is a view of the housing member shown in FIG. 16 (showing a portion where the projection of the first region along the first direction is located within the first groove);

[0074] FIG19 is a partial enlarged view of a housing component (the surface of the convex portion facing away from the second surface is an arc surface) provided in some embodiments of the present application;

[0075] FIG20 is a partial enlarged view of a housing component (the surface of the convex portion facing away from the second surface is an arc surface) provided in some other embodiments of the present application;

[0076] FIG21 is a schematic structural diagram of a housing component (the first groove portion is V-shaped) provided in some embodiments of the present application;

[0077] FIG22 is a schematic structural diagram of a housing component (the first groove portion is U-shaped) provided in some embodiments of the present application;

[0078] FIG23 is a schematic structural diagram of a housing component (the first groove portion is H-shaped) provided in some embodiments of the present application;

[0079] FIG24 is a schematic diagram of a housing component provided in some embodiments of the present application (the first groove is arc-shaped);

[0080] FIG25 is a schematic structural diagram of a housing component (the first groove portion is annular) provided in some embodiments of the present application;

[0081] FIG26 is an isometric view of a housing component provided in some embodiments of the present application;

[0082] FIG27 is a schematic structural diagram of the housing member shown in FIG26 (showing the first groove portion and the second groove portion);

[0083] FIG28 is a JJ sectional view of the housing member shown in FIG27 ;

[0084] FIG29 is a schematic structural diagram of a housing component (both the first groove portion and the second groove portion are H-shaped grooves) provided in some embodiments of the present application;

[0085] FIG30 is a cross-sectional view of the housing member taken along line KK shown in FIG29 ;

[0086] FIG31 is a schematic structural diagram of a housing component (showing a first slot portion, a second slot portion, and a third slot portion) provided in some embodiments of the present application;

[0087] FIG32 is a sectional view taken along line MM of the housing member shown in FIG31;

[0088] FIG33 is a schematic structural diagram of an end cap provided in some embodiments of the present application;

[0089] FIG34 is a schematic structural diagram of a housing provided in some embodiments of the present application;

[0090] FIG35 is a cross-sectional view of a shell provided in some other embodiments of the present application.

[0091] Icons: 1-housing; 11-shell; 12-end cap; 121-wall; 121a-side wall; 121b-bottom wall; 2-electrode assembly; 21-positive ear; 22-negative ear; 3-positive electrode terminal; 4-negative electrode terminal; 5-housing component; 51-first surface; 52-second surface; 53-first groove; 531-first groove bottom; 5311-edge line; 532-first groove side; 533-connection position; 534-second contour line; 535-first groove section; 536-second groove section; 537-third groove section; 538-first position; 539-second Position; 54-weak area; 55-convex portion; 551-first contour line; 552-outer side surface; 553-first end surface; 554-arc surface; 56-pressure relief area; 57-second groove portion; 571-bottom wall of the second groove portion; 58-third surface; 59-third groove portion; 591-bottom wall of the third groove portion; 10-battery cell; 20-casing; 201-first part; 202-second part; 100-battery; 200-controller; 300-motor; 1000-vehicle; X-width direction of the first groove portion; Y-extension direction of the first groove portion; Z-first direction. DETAILED DESCRIPTION

[0092] 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.

[0093] 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.

[0094] 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.

[0095] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0096] 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.

[0097] 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.

[0098] The term "plurality" used in this application refers to two or more (including two).

[0099] 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.

[0100] The battery cells can be 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., which are not limited in the embodiments of the present application.

[0101] 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 of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0102] 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.

[0103] 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.

[0104] 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 or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0105] 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.

[0106] 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.

[0107] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0108] 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.).

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0114] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical and mechanical stability can be selected.

[0115] As an example, the primary material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component positioned between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0116] 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.

[0117] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not specifically limit the type of electrolyte, and the electrolyte can be selected based on needs. The electrolyte can be liquid, gel, or solid.

[0118] The liquid electrolyte includes an electrolyte salt and a solvent.

[0119] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0120] In some embodiments, the solvent can be selected from 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 can also be an ether solvent. Ether solvents can 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.

[0121] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0122] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0123] 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.

[0124] As an example, the inorganic solid electrolyte can be an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphide, germanium silver sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0125] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0126] 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.

[0127] In some embodiments, the electrode assembly is a laminate structure.

[0128] 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.

[0129] 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.

[0130] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0131] 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.

[0132] 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.

[0133] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0134] 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.

[0135] 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.

[0136] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, and a polygonal battery. The polygonal battery is, for example, a hexagonal battery, etc. There is no special limitation in this application.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0142] The battery mentioned in the embodiments of the present application may include one or more battery cells to provide a single physical module with higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel or in hybrid through a busbar.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0147] 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, battery reliability must also be considered.

[0148] In a battery cell, a pressure relief mechanism may be provided on the outer shell of the battery cell. When the battery cell experiences thermal runaway, the pressure inside the battery cell is released through the pressure relief mechanism to improve the reliability of the battery cell.

[0149] For typical battery cells, the pressure relief mechanism is welded to the outer casing to secure it to the outer casing. For example, if the pressure relief mechanism is a rupture-proof disc installed on the end cap of the outer casing, in the event of thermal runaway of the battery cell, the rupture-proof disc is destroyed, thereby releasing the pressure inside the battery cell. Because the pressure relief mechanism is welded to the outer casing, cracks may form at the weld during long-term use of the battery cell, reducing the strength of the weld. This weld is prone to damage when the pressure inside the battery cell does not reach the detonation pressure of the pressure relief mechanism, causing the pressure relief mechanism to fail and reduce its reliability.

[0150] To improve the reliability of the pressure relief mechanism, the pressure relief mechanism and the housing can be integrated into a single structure, with a portion of the housing serving as the pressure relief mechanism. For example, the end cap or shell of the housing can be partially weakened to reduce the strength of the end cap, forming a weak area, thereby forming an integrated pressure relief mechanism. This can effectively improve the reliability of the pressure relief mechanism.

[0151] The inventors noticed that after forming an integrated pressure relief mechanism on the shell, the mechanical properties of the weak area of ​​the shell are poor. Under normal use conditions of the battery cell, the weak area is prone to fatigue damage due to long-term changes in the internal pressure of the battery cell, affecting the service life of the battery cell.

[0152] In view of this, an embodiment of the present application provides a shell component, which includes a first surface and a second surface, the first surface and the second surface are arranged opposite to each other along a first direction, and the shell component is provided with a first groove portion that is recessed from the first surface along a direction close to the second surface; the shell component forms a weak area at the bottom of the first groove portion, and the weak area is configured to be destroyed when the battery cell releases internal pressure, and a convex portion protruding from the second surface is provided on the side of the weak area away from the first groove portion along the first direction.

[0153] In such a shell component, a convex portion protruding from the second surface is provided on the side of the weak area away from the first groove portion. The convex portion strengthens the weak area, can improve the fatigue strength of the weak area, and reduce the risk of the weak area being damaged during normal use of the battery cell, thereby increasing the service life of the battery cell.

[0154] The housing component provided in the embodiment of the present application is applicable to battery cells, batteries, and electrical equipment using batteries.

[0155] 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.

[0156] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0157] 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.

[0158] 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.

[0159] 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.

[0160] 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 housing 20 is used to accommodate the battery cell 10.

[0161] 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 cylinder. 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, 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, forming the housing 20 with a storage space. As an example, the battery cell 10 can be a cylindrical battery cell 10, a prismatic battery cell 10, a soft-pack battery cell 10 or a battery cell 10 of other shapes. The prismatic battery cell 10 includes a square-shell battery cell 10, a blade-shaped battery cell 10, and a polygonal battery 100. The polygonal battery 100 is, for example, a hexagonal battery 100, etc. There is no special limitation in this application.

[0162] 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.

[0163] Please refer to Figure 3, which is an exploded 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.

[0164] The housing 1 is used to house the electrode assembly 2 and other components such as the electrolyte. The housing 1 may be a steel shell, an aluminum shell, a plastic shell (e.g., polypropylene), a composite metal shell (e.g., a copper-aluminum composite housing 1), or an aluminum-plastic film. As an example, the housing 1 may include a shell 11 and an end cap 12.

[0165] The housing 11 may be a hollow structure with an opening at one end, or a hollow structure with openings at two opposite ends. The housing 11 may be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, and the like.

[0166] 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 storage 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 cylinder, 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 various, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0167] In the battery cell 10, there can be one or two end caps 12. In embodiments where the housing 11 is a hollow structure with openings at both ends, two end caps 12 can be provided. The two end caps 12 respectively close the two openings of the housing 11, and the two end caps 12 and the housing 11 together define a storage space. In embodiments where the housing 11 is a hollow structure with an opening at one end, there can be one end cap 12 provided. The end cap 12 closes the opening at one end of the housing 11, and the end cap 12 and the housing 11 together define a storage space.

[0168] In some embodiments, the battery cell 10 may further include electrode terminals, which may be disposed on the housing 1 and electrically connected to the tabs of the electrode assembly 2 to output electrical energy from the battery cell 10. The electrode terminals may be directly connected to the tabs, for example, by direct welding. They may also be indirectly connected to the tabs, for example, through a current collecting member. The current collecting member may be a metal conductor, such as copper, iron, aluminum, steel, or an aluminum alloy.

[0169] As an example, as shown in Figure 3, the shell 11 is a hollow structure with an opening at one end, and the end cover 12 closes the opening of the shell 11. Two electrode terminals can be set on the end cover 12. The two electrode terminals are a positive electrode terminal 3 and a negative electrode terminal 4. The positive electrode terminal 3 is electrically connected to the positive electrode ear 21 of the electrode assembly 2, and the negative electrode terminal 4 is electrically connected to the negative electrode ear 22 of the electrode assembly 2.

[0170] Please refer to Figures 4 and 5. Figure 4 is a schematic structural diagram of a housing component 5 provided in some embodiments of the present application; Figure 5 is a cross-sectional view taken along line AA of the housing component 5 shown in Figure 4. Embodiments of the present application provide a housing component 5 for use with a battery cell 10. The housing component 5 includes a first surface 51 and a second surface 52. The first surface 51 and the second surface 52 are arranged opposite each other along a first direction Z. The housing component 5 is provided with a first groove 53 that is recessed from the first surface 51 in a direction approaching the second surface 52. The housing component 5 forms a weak area 54 at the bottom of the first groove 53. The weak area 54 is configured to be destroyed when the battery cell 10 releases internal pressure. Along the first direction Z, a protrusion 55 that protrudes from the second surface 52 is provided on the side of the weak area 54 that is away from the first groove 53.

[0171] The housing component 5 is a component that can accommodate the electrode assembly 2 together with other components. The housing component 5 can be a portion of the housing 1 of the battery cell 10, the end cap 12 of the housing 1 can be the housing component 5, or the shell 11 of the housing 1 can be the housing component 5. The housing component 5 can be made of metal, such as copper, iron, aluminum, steel, or an aluminum alloy. The housing component 5 can also be the outer shell of the battery cell 10. For example, the housing component 5 can be an aluminum-plastic film that is coated on the outside of the electrode assembly 2 to form a soft-pack battery.

[0172] The first surface 51 and the second surface 52 are two opposing surfaces of the outer shell component 5. Both the first surface 51 and the second surface 52 can be flat, and the first surface 51 can be parallel to the second surface 52. One of the first surface 51 and the second surface 52 faces the interior of the battery cell 10, while the other faces away from the interior of the battery cell 10. For example, taking the outer shell component 5 as the end cap 12, the first direction Z is the thickness direction of the end cap 12. The first surface 51 and the second surface 52 can be the surfaces of the end cap 12 that are farthest apart along the thickness direction. The distance between the first surface 51 and the second surface 52 is the thickness of the end cap 12. Of course, the distance between the first surface 51 and the second surface 52 can also be less than the thickness of the end cap 12. For example, taking the outer shell component 5 as the housing 11, the first direction Z is the thickness direction of the housing 11. The first surface 51 and the second surface 52 can be the surfaces of a wall portion of the housing 11 that are farthest apart along the thickness direction. The distance between the first surface 51 and the second surface 52 is the thickness of the wall portion. Of course, the distance between the first surface 51 and the second surface 52 can also be less than the thickness of the wall portion 121.

[0173] As an example, in the embodiment shown in FIG5 , the first surface 51 and the second surface 52 are respectively located on either side of the end cap 12, and the distance between the first surface 51 and the second surface 52 is the thickness of the end cap 12. The first surface 51 is the outer surface of the end cap 12, and the second surface 52 is the inner surface of the end cap 12, which faces the interior of the battery cell 10.

[0174] Along the first direction Z, the first groove portion 53 is recessed from the first surface 51 in a direction close to the second surface 52, and the first direction Z is the depth direction of the first groove portion 53. The first groove portion 53 can be formed in a variety of ways, such as stamping, laser etching, milling, etc. The first groove portion 53 can be a groove of various shapes, such as a linear groove, a circular groove, an elliptical groove, an annular groove, an arc-shaped groove, a U-shaped groove, an H-shaped groove, etc. Among them, a circular groove refers to a groove with a circular cross-section, and an elliptical groove refers to a groove with an elliptical cross-section, which is perpendicular to the first direction Z. As an example, in the embodiments shown in Figures 4 and 5, the first groove portion 53 is a linear groove.

[0175] A weak area 54 is formed at the bottom of the first groove portion 53. Along the first direction Z, the portion of the shell component 5 located between the bottom surface of the first groove portion 53 and the second surface 52 is the weak area 54. The weak area 54 is weaker than other areas of the shell component 5. After the first groove portion 53 is formed on the shell component 5, the shell component 5 is thinned in the area where the first groove portion 53 is provided, correspondingly forming the weak area 54. The shell component 5 also includes a non-weak area surrounding the outside of the first groove portion 53. It can be understood that the weak area 54 is integrally formed with the non-weak area. Among them, the strength of the weak area 54 is less than that of the non-weak area. The weak area 54 can be destroyed by rupture, falling off, etc. For example, when the internal pressure of the battery cell 10 reaches a threshold value, the weak area 54 ruptures under the action of the emissions (gas, electrolyte, etc.) inside the battery cell 10, so that the emissions inside the battery cell 10 can be discharged smoothly.

[0176] The protrusion 55 protrudes from the second surface 52 and is connected to the weak area 54. The protrusion 55 and the weak area 54 can be integrally formed, or they can be separately provided and connected, for example, by welding. The protrusion 55 reinforces the weak area 54 and can cover a portion of the weak area 54 or completely. The protrusion 55 can be continuous and extend along the extension direction of the weak area 54. For example, if the first groove 53 is a linear groove, the weak area 54 extends along a linear trajectory, and the protrusion 55 also extends along a linear trajectory. For another example, if the first groove 53 is an arc-shaped groove, the weak area 54 extends along a circular arc trajectory, and the protrusion 55 also extends along a circular arc trajectory. Of course, the protrusion 55 can also be discontinuous, for example, the protrusion 55 includes multiple segments, and the multiple segments are arranged at intervals along the extension direction Y of the first groove 53.

[0177] In the embodiment of the present application, a protrusion 55 protruding from the second surface 52 is provided on the side of the weak area 54 away from the first groove portion 53. The protrusion 55 strengthens the weak area 54, thereby improving the fatigue strength of the weak area 54 and reducing the risk of the weak area 54 being damaged during normal use of the battery cell 10, thereby improving the service life of the battery cell 10.

[0178] In some embodiments, please refer to Figures 6 and 7. Figure 6 is a partial enlarged view of the housing component 5 (the first groove bottom surface 531 is a flat surface) at point B shown in Figure 5; Figure 7 is a partial enlarged view of the housing component 5 (the first groove bottom surface 531 is an arcuate surface 554) provided in some embodiments of the present application. Along the first direction Z, the first groove portion 53 includes a first groove bottom surface 531 located between the first surface 51 and the second surface 52. The minimum distance between the first groove bottom surface 531 and the second surface 52 is D. The height of the protrusion 55 protruding from the second surface 52 is H, and 0.01≤H / (D+H)≤0.67.

[0179] The bottom surface of the first groove portion 53 is a first groove bottom surface 531. The first groove bottom surface 531 can be a plane, and can be parallel to the second surface 52, or can be arranged at a small angle, for example, the angle between the first groove bottom surface 531 and the second surface 52 is within 10 degrees. The first groove bottom surface 531 can also be a curved surface, for example, the first groove bottom surface 531 is an arc-shaped surface 554 with a cross-section that is perpendicular to the extension direction Y of the first groove portion (shown in FIG. 4 ).

[0180] The minimum distance D between the first groove bottom surface 531 and the second surface 52 is the minimum thickness of the weak area 54 in the first direction Z. The height H of the protrusion 55 protruding from the second surface 52 is the maximum thickness of the protrusion 55 in the first direction Z.

[0181] As an example, in the embodiment shown in Figure 6, the bottom surface 531 of the first groove is a plane, the bottom surface 531 of the first groove is parallel to the second surface 52, and the thickness of the weak zone 54 is uniform; in the embodiment shown in Figure 7, the bottom surface 531 of the first groove is a circular arc surface 554, and the distance from the position of the bottom surface 531 of the first groove closest to the second surface 52 along the first direction Z to the second surface 52 is D, and the thickness of the weak zone 54 is uneven. Along the width direction X of the first groove portion, the thickness of the weak zone 54 gradually increases from the middle to both ends.

[0182] H / (D+H) can be any one of 0.01, 0.02, 0.03, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.33, 0.35, 0.4, 0.45, 0.5, 0.52, 0.55, 0.6, 0.65, 0.67, or a range between any two of them.

[0183] The inventors conducted multiple experiments on battery cells 10 with end caps 12 as the outer shell component 5, and statistically analyzed the cracking rate of the weak area 54 of each battery cell 10 under normal use conditions and the explosion rate of the battery cell 10 during thermal runaway. The test results are shown in Table 1 below.

[0184] (1) The cracking rate of the weak area 54 of the battery cell 10 under normal use conditions is measured.

[0185] The battery cells 10 were placed at 25±2°C and cycled between 5% and 97% SOC. The gas pressure within the cells 10 was monitored, and 1000 tests were performed simultaneously. The test ended when the battery cell 10 lifespan decreased to 80% SOH or when any group of cells 10 cracked in the weak area 54 during cycling. The criterion for cracking in the weak area 54 was when the internal pressure of the battery cell 10 decreased by >10% of the maximum pressure. The crack rate in the weak area 54 was calculated as: number of cracks / total number of cracks*100%.

[0186] (2) Measure the explosion rate of the battery cell 10 during thermal runaway.

[0187] A small heating film was built into each battery cell 10. The heating film was energized to heat the battery cell 10 until thermal runaway occurred. The battery cell 10 was observed to see if it exploded. This test was repeated 1,000 times, and the explosion rate of the battery cells 10 was calculated: explosion rate = number of explosions / total number of explosions * 100%.

[0188] Table 1

[0189] Table 1 shows that when H / (D+H)>0.67, the strength of the weak zone 54 is too high, making it more difficult for the weak zone 54 to be destroyed during thermal runaway of the battery cell 10. This can lead to untimely pressure relief and a higher probability of explosion of the battery cell 10, with the probability of explosion exceeding 25%. When H / (D+H)<0.01, the protrusion 55's ability to reinforce the weak zone 54 is insufficient, increasing the risk of destruction of the weak zone 54 during normal use of the battery cell 10. Under normal use conditions, the cracking rate of the weak zone 54 exceeds 7%. When H / (D+H)≤0.67, the risk of destruction of the weak zone 54 during normal use of the battery cell 10 is further reduced, extending the service life of the battery cell 10, and reducing the risk of explosion of the battery cell 10 during thermal runaway, thereby improving the reliability of the battery cell 10.

[0190] In some embodiments, 0.03≤H / (D+H)≤0.33.

[0191] H / (D+H) can be any one of 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, or a range between any two of them.

[0192] As can be seen from Table 1, when 0.03≤H / (D+H)≤0.33, the overall performance of the outer shell component 5 is better, so that the weak area 54 can be destroyed in time when the battery cell 10 has thermal runaway, and the weak area 54 has sufficient fatigue strength under normal use conditions of the battery cell 10, thereby improving the service life of the battery cell 10.

[0193] In some embodiments, along the first direction Z, the height of the protrusion 55 protruding from the second surface 52 is H, and 0.01 mm≤H≤0.96 mm.

[0194] H can be any point value among 0.01mm, 0.03mm, 0.05mm, 0.1mm, 0.3mm, 0.55mm, 0.6mm, 0.7mm, 0.9mm, 0.96mm, or a range of values ​​between any two of them.

[0195] In this embodiment, 0.01 mm ≤ H ≤ 0.96 mm, so that the height of the protrusion 55 is not too high while effectively reinforcing the weak area 54, thereby reducing the space occupied by the protrusion 55 outside or inside the battery cell 10. Of course, if the protrusion 55 is located inside the battery cell 10, setting the height of the protrusion 55 within a reasonable range can reduce the space occupied by the protrusion 55 inside the battery cell 10; if the protrusion 55 is located outside the battery cell 10, setting the height of the protrusion 55 within a reasonable range can reduce the space occupied by the protrusion 55 outside the battery cell 10.

[0196] In some embodiments, 0.05 mm ≤ H ≤ 0.55 mm.

[0197] H can be any one of 0.05mm, 0.07mm, 0.09mm, 0.1mm, 0.13mm, 0.15mm, 0.17mm, 0.19mm, 0.21mm, 0.23mm, 0.25mm, 0.27mm, 0.29mm, 0.3mm, 0.31mm, 0.33mm, 0.35mm, 0.37mm, 0.39mm, 0.41mm, 0.43mm, 0.45mm, 0.47mm, 0.49mm, 0.51mm, 0.53mm, 0.55mm, or a range between any two of them.

[0198] In this embodiment, 0.05 mm≤H≤0.55 mm, which further reduces the space occupied by the protrusion 55 outside or inside the battery cell 10 and enhances the reinforcing effect of the protrusion 55 on the weak area 54 .

[0199] In some embodiments, referring again to Figures 6 and 7 , the first groove portion 53 includes a first groove bottom surface 531 and a first groove side surface 532 connected to the first groove bottom surface 531. The first groove side surface 532 forms an angle θ with the first groove bottom surface 531, measured in degrees. The first groove side surface 532 connects to the first groove bottom surface 531 at a connection position 533. Along the first direction Z, the minimum residual thickness of the housing component 5 at the connection position 533 is L, measured in mm. 90≤θ / L≤5833.

[0200] θ / L can be any one of 90, 100, 111, 200, 220, 300, 400, 500, 600, 650, 700, 800, 900, 933, 1200, 1500, 2000, 2500, 3200, 4000, 5000, 5833, or a range between any two of them.

[0201] The first groove side surface 532 is connected to the edge of the first groove bottom surface 531. In the width direction X of the first groove portion, the first groove portion 53 has two opposing first groove side surfaces 532, which are respectively connected to the two sides of the first groove bottom surface 531. The angle θ between the first groove side surface 532 and the first groove bottom surface 531 is the angle between the first groove side surface 532 and the first groove bottom surface 531 within the same cross-section, where the cross-section is perpendicular to the extension direction Y of the first groove portion.

[0202] The first groove side surface 532 and the first groove bottom surface 531 are connected at the edge of the first groove bottom surface 531. The edge line 5311 of the first groove bottom surface 531 (not shown in Figures 6 and 7) is the connection point 533 between the first groove bottom surface 531 and the first groove side surface 532. Along the first direction Z, the thickness of the remaining portion of the housing component 5 after the first groove portion 53 is provided at the connection point 533 is the minimum residual thickness L of the housing component 5 at the connection point 533. The minimum residual thickness L can be measured at the edge line 5311 of the first groove bottom surface 531.

[0203] It should be noted that, as shown in Figure 7, in the embodiment where the first groove bottom surface 531 is an arc surface 554, the angle θ between the first groove bottom surface 531 and the first groove side surface 532 is the angle between the tangent of the first groove bottom surface 531 at the connection position 533 and the first groove side surface 532.

[0204] The inventors conducted multiple sets of experiments on battery cells 10 with end caps 12 as the outer shell component 5. The θ / L ratio was different in each set of experiments. The cracking rate of the weak area 54 of each battery cell 10 under normal use conditions and the explosion rate of the battery cell 10 during thermal runaway were calculated. The test results are shown in Table 2 below.

[0205] Table 2

[0206] Table 2 shows that when θ / L>5833, the cracking rate of the weak area 54 under normal battery cell usage conditions and the probability of explosion of the battery cell 10 during thermal runaway are both high. When θ / L<90, the cracking rate of the weak area 54 under normal battery cell usage conditions and the probability of explosion of the battery cell 10 during thermal runaway are also high. When 90≤θ / L≤5833, the cracking rate of the weak area 54 under normal battery cell usage conditions and the probability of explosion of the battery cell 10 during thermal runaway are both low, thereby extending the service life of the battery cell 10 and reducing the risk of explosion of the battery cell 10 during thermal runaway, thereby improving the reliability of the battery cell.

[0207] In some embodiments, 220≤θ / L≤933.

[0208] θ / L can be any one of 220, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 933, or a range between any two of them.

[0209] According to Table 2, when 220≤θ / L≤933, the cracking rate of the weak area 54 under normal use conditions of the battery cell and the probability of explosion of the battery cell 10 during thermal runaway are further reduced, thereby further improving the service life of the battery cell 10 and the reliability of the battery cell 10.

[0210] In some embodiments, 90°≤θ≤175°.

[0211] θ can be any point value among 90°, 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, 150°, 155°, 160°, 165°, 170°, 175°, or a range between any two of them.

[0212] In some embodiments, 0.03 mm ≤ L ≤ 1 mm.

[0213] θ can be any point value among 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, or a range between any two of them.

[0214] In some embodiments, referring to Figures 6-8, Figure 8 is a view of the housing component 5 shown in Figure 6 taken along an arrow C. Along the first direction Z, the first groove portion 53 includes a first groove bottom surface 531 located between the first surface 51 and the second surface 52. The outer surface of the protrusion 55 is connected to the second surface 52 to form a first contour line 551, and the projection of the first contour line 551 along the first direction Z is located within the first groove bottom surface 531.

[0215] The location where the outer surface of the protrusion 55 connects with the second surface 52 forms a first contour line 551. As an example, as shown in Figures 6 and 7, the outer surface of the protrusion 55 includes an outer side surface 552 and a first end surface 553 facing away from the second surface 52 along the first direction Z. The outer side surface 552 surrounds the first end surface 553 and connects to the second surface 52 of the first end surface 553. The location where the outer side surface 552 connects with the second surface 52 forms the first contour line 551. As shown in Figure 8, with the protrusion 55 extending along a straight line, the first contour line 551 is a rectangle.

[0216] The first end surface 553 and the outer side surface 552 may be perpendicular or may be arranged at an obtuse angle. As an example, in the embodiments shown in Figures 6 and 7 , the first end surface 553 and the outer side surface 552 are arranged at an obtuse angle.

[0217] The first groove portion 53 forms a second contour line 534 on the first surface 51. As an example, along the first direction Z, the projection of the first groove bottom surface 531 is located within the second contour line 534 and does not contact the second contour line 534.

[0218] In this embodiment, the projection of the first contour line 551 along the first direction Z is located within the bottom surface 531 of the first groove, which reduces the coverage of the protrusion 55 on the weak area 54, reduces the difficulty of the weak area 54 being destroyed when the battery cell 10 thermally runs away, and timely releases the pressure inside the battery cell 10.

[0219] 6-9 , FIG9 is a view of the housing component 5 shown in FIG6 along the arrow E. The projection of the first contour line 551 along the first direction Z coincides with the edge line 5311 of the first groove bottom surface 531 within the first groove bottom surface 531 .

[0220] In the embodiments shown in Figures 6 and 7 , the minimum distance between the edge line 5311 of the first groove bottom surface 531 and the second surface 52 along the first direction Z, i.e., the minimum residual thickness of the housing component 5 at the connection position 533, is L. In the embodiment shown in Figure 6 , L=D; in the embodiment shown in Figure 7 , L>D.

[0221] As shown in FIG. 9 , taking the first groove bottom surface 531 as a rectangle as an example, the four sides of the rectangle together form an edge line 5311 of the first groove bottom surface 531 .

[0222] In this embodiment, the protrusion 55 completely covers the weak area 54, effectively reinforcing the weak area 54, improving its fatigue resistance and reducing the risk of damage during normal use of the battery cell 10. Furthermore, the weak area 54 is weaker at the edge 5311 of the first groove bottom surface 531, which facilitates its destruction in the event of thermal runaway of the battery cell 10.

[0223] In some embodiments, please refer to Figures 10 to 12. Figure 10 is a partially enlarged view of the housing component 5 provided in some embodiments of the present application (the projection of the first contour line 551 within the first groove bottom surface 531 does not contact the edge line 5311 of the first groove bottom surface 531). Figure 11 is a partially enlarged view of the housing component 5 provided in other embodiments of the present application (the projection of the first contour line 551 within the first groove bottom surface 531 does not contact the edge line 5311 of the first groove bottom surface 531). Figure 12 is a view of the housing component 5 shown in Figure 10 taken along the arrow F. The projection of the first contour line 551 along the first direction Z within the first groove bottom surface 531 does not contact the edge line 5311 of the first groove bottom surface 531.

[0224] It can be understood that, within the first groove bottom surface 531 , the projection of the first contour line 551 along the first direction Z is located on the inner side of the edge line 5311 of the first groove bottom surface 531 .

[0225] As an example, as shown in Figures 10 and 11 , along the first direction Z, the minimum distance between the edge line 5311 of the first groove bottom surface 531 and the second surface 52 is the minimum residual thickness of the housing component 5 at the connection location 533, L, where L = D. In the embodiment shown in Figure 10 , the first end surface 553 of the protrusion 55 is perpendicular to the outer side surface 552; in the embodiment shown in Figure 11 , the first end surface 553 of the protrusion 55 is disposed at an obtuse angle to the outer side surface 552.

[0226] As an example, as shown in FIG12 , the first contour line 551 and the edge line 5311 are both rectangles.

[0227] In this embodiment, there is an area in the weak zone 54 that is not covered by the protrusion 55 . This area is thinner and is more easily damaged when the battery cell 10 experiences thermal runaway, thereby improving the timeliness of pressure relief of the battery cell 10 .

[0228] In some embodiments, please refer to Figures 13 to 16. Figure 13 is a partial enlarged view of an external component provided in some embodiments of the present application (the projection of the edge line 5311 of the first groove bottom surface 531 along the first direction Z is located within the first region and does not contact the first contour line 551); Figure 14 is a G-direction view of the housing component 5 shown in Figure 13; Figure 15 is a partial enlarged view of an external component provided in other embodiments of the present application (the projection of the edge line 5311 of the first groove bottom surface 531 along the first direction Z is located within the first region and does not contact the first contour line 551); Figure 16 is a partial enlarged view of an external component provided in still other embodiments of the present application (the projection of the edge line 5311 of the first groove bottom surface 531 along the first direction Z is located within the first region and does not contact the first contour line 551). Along the first direction Z, the first groove portion 53 includes a first groove bottom surface 531 located between the first surface 51 and the second surface 52. The outer surface of the protrusion 55 is connected to the second surface 52 to form a first contour line 551 , which defines a first area. The projection of the edge line 5311 of the first groove bottom surface 531 along the first direction Z is located in the first area and does not contact the first contour line 551 .

[0229] It can be understood that, in the first region, the projection of the edge line 5311 of the first groove bottom surface 531 along the first direction Z is located inside the first contour line 551. The shaded area shown in FIG14 is the first region.

[0230] As an example, as shown in Figure 13, the first end surface 553 of the protrusion 55 forms an obtuse angle with the outer side surface 552. The projection of the edge line 5311 of the first groove bottom surface 531 along the first direction Z lies within the outer side surface 552 of the protrusion 55. Along the first direction Z, the minimum distance between the edge line 5311 of the first groove bottom surface 531 and the outer side surface 552 of the protrusion 55 is the minimum residual thickness L of the housing component 5 at the connection position 533, where L>D.

[0231] As an example, as shown in Figure 15 , the first end surface 553 of the protrusion 55 forms an obtuse angle with the outer side surface 552. The projection of the edge line 5311 of the first groove bottom surface 531 along the first direction Z lies within the first end surface 553 of the protrusion 55. Along the first direction Z, the minimum distance between the edge line 5311 of the first groove bottom surface 531 and the first end surface 553 of the protrusion 55 is the minimum residual thickness L of the housing component 5 at the connection location 533, where L>D.

[0232] As an example, as shown in Figure 16, the first end surface 553 of the protrusion 55 forms an obtuse angle with the outer side surface 552. A portion of the projection of the edge line 5311 of the first groove bottom surface 531 along the first direction Z lies within the first end surface 553 of the protrusion 55, while another portion lies within the outer side surface 552 of the protrusion 55. Along the first direction Z, the minimum distance between the edge line 5311 of the first groove bottom surface 531 and the outer side surface 552 of the protrusion 55 is the minimum residual thickness L of the housing component 5 at the connection location 533, where L>D.

[0233] In this embodiment, the protrusion 55 completely covers the weak area 54. The protrusion 55 is connected to the weak area 54 and is also connected to the area of ​​the shell component 5 other than the weak area 54, further enhancing the reinforcement effect of the protrusion 55 on the weak area 54 and further improving the fatigue strength of the weak area 54.

[0234] In some embodiments, referring to Figures 16-18, Figure 17 is a view of the housing component 5 shown in Figure 16 (showing the first region) taken along an arrow I; Figure 18 is a view of the housing component 5 shown in Figure 16 (showing the portion of the first region projected along the first direction Z within the first groove 53) taken along an arrow I. The outer surface of the protrusion 55 is connected to the second surface 52 to form a first contour line 551. The first contour line 551 defines a first region. The area of ​​the first region is S1. The area of ​​the portion of the first region projected along the first direction Z within the first groove 53 is S2, where S2 / S1 ≥ 0.6.

[0235] S2 / S1 can be any one of 0.6, 0.7, 0.8, 0.9, 1, or a range of values ​​between any two.

[0236] The first groove 53 forms a second contour line 534 on the first surface 51. The portion of the projection of the first region along the first direction Z that lies within the second contour line 534 is also the portion of the projection of the first region along the first direction Z that lies within the first groove 53. In other words, the area of ​​overlap between the projection of the region defined by the second contour line 534 along the first direction Z and the projection of the first region along the first direction Z is S2.

[0237] As an example, in the embodiments shown in Figures 17 and 18, the first contour line 551 is a rectangle, and the first region is the rectangular region defined by the first contour line 551. The shaded area shown in Figure 17 is the first region, and the shaded area shown in Figure 18 is the portion of the first region's projection along the first direction Z that is located within the first groove 53.

[0238] In this embodiment, S2 / S1 ≥ 0.6, so that more parts of the protrusions 55 can cover the weak area 54 , thereby improving the reinforcing effect of the protrusions 55 on the weak area 54 .

[0239] In some embodiments, referring to FIG. 6 , FIG. 7 , FIG. 10 , FIG. 11 , FIG. 13 , FIG. 15 and FIG. 16 , along the first direction Z, the surface of the protrusion 55 away from the second surface 52 is a plane.

[0240] The surface of the protrusion 55 facing away from the second surface 52 is the first end surface 553 of the protrusion 55 , i.e., the first end surface 553 is a plane. Along the first direction Z, there is a certain distance between the first end surface 553 and the second surface 52 . The distance between the first end surface 553 and the second surface 52 is the height of the protrusion 55 protruding from the second surface 52 .

[0241] In this embodiment, the surface of the protrusion 55 facing away from the second surface 52 is a plane, so that the thickness of the area of ​​the protrusion 55 covered by the plane is more uniform, and different areas of the weak area 54 are uniformly reinforced. The protrusion 55 of this structure is easier to shape.

[0242] In some embodiments, please refer to Figures 19 and 20. Figure 19 is a partial enlarged view of the housing component 5 provided in some embodiments of the present application (the surface of the protrusion 55 facing away from the second surface 52 is a circular arc surface 554); Figure 20 is a partial enlarged view of the housing component 5 provided in other embodiments of the present application (the surface of the protrusion 55 facing away from the second surface 52 is a circular arc surface 554). Along the first direction Z, the surface of the protrusion 55 facing away from the second surface 52 is a circular arc surface 554, and the cross-section of the circular arc surface 554 is an arc that bulges in the direction away from the second surface 52 at the middle position.

[0243] The cross section of the arcuate surface 554 is perpendicular to the extension direction of the protrusion 55. For example, if the protrusion 55 is a long strip extending along a straight line, the cross section of the arcuate surface 554 is perpendicular to the straight line. For another example, if the protrusion 55 is an arcuate structure extending along a circular arc, the cross section of the arcuate surface 554 is perpendicular to the circular arc. As an example, in the embodiments shown in Figures 19 and 20, the cross section is parallel to the first direction Z and the width direction X of the first groove, and the extension direction of the protrusion 55 is perpendicular to the first direction Z and the width direction X of the first groove.

[0244] The first arc surface 554 and the second surface 52 may be directly connected or indirectly connected.

[0245] As an example, as shown in FIG19 , arcuate surface 554 is directly connected to second surface 52. Arcuate surface 554 is the outer surface of convex portion 55. Arcuate surface 554 and second surface 52 are connected to form first contour line 551. First contour line 551 defines a first region. The projection of edge line 5311 (not shown in FIG19 ) of first groove bottom surface 531 along first direction Z is located within the first region and does not contact first contour line 551. Along the first direction Z, the distance from edge line 5311 of first groove bottom surface 531 to arcuate surface 554 is the minimum residual thickness L of housing component 5 at connection position 533.

[0246] As an example, as shown in FIG20 , the arcuate surface 554 is indirectly connected to the second surface 52 via the outer side surface 552 of the protrusion 55. The arcuate surface 554 is the first end surface 553 of the protrusion 55 facing away from the second surface 52 (not shown in FIG20 ). The outer side surface 552 of the protrusion 55 and the arcuate surface 554 together form the outer surface of the protrusion 55. The outer side surface 552 of the protrusion 55 is connected to the second surface 52 to form a first contour line 551. The projection of the first contour line 551 along the first direction Z is within the first groove bottom surface 531 and does not contact the edge line 5311 of the first groove bottom surface 531 (not shown in FIG20 ).

[0247] In this embodiment, the surface of the protrusion 55 facing away from the second surface 52 is an arc surface 554. This structure makes the cross-section of the protrusion 55 roughly arched, with better deformation resistance. When the protrusion 55 is subjected to impact force, it is not easy to cause damage to the weak area 54.

[0248] In some embodiments, the extending direction of the protrusion 55 is consistent with the extending direction Y of the first groove.

[0249] For example, the first groove portion 53 is a linear groove extending along a linear trajectory, and the convex portion 55 is a long strip structure extending along a linear trajectory; for another example, the first groove portion 53 is an annular groove, and the convex portion 55 is an annular structure; for another example, the first groove portion 53 is an arc-shaped groove, and the convex portion 55 is an arc-shaped structure; for another example, the first groove portion 53 is a U-shaped groove, and the convex portion 55 is a U-shaped structure; for another example, the first groove portion 53 is an H-shaped groove, and the convex portion 55 is an H-shaped structure.

[0250] In this embodiment, the extension direction of the protrusion 55 is consistent with the extension direction Y of the first groove portion, so as to strengthen more areas of the weak zone 54 and enhance the strengthening effect of the protrusion 55 on the weak zone 54 .

[0251] In some embodiments, the protrusion 55 is integrally formed with the weak area 54 , so that the protrusion 55 has a better reinforcement effect on the weak area 54 .

[0252] In some embodiments, the first groove portion 53 is stamped and formed on the housing component 5 .

[0253] When the first groove 53 is stamped on the housing component 5 , a convex portion 55 protruding from the second surface 52 may be formed at a position corresponding to the first groove 53 , thereby achieving integral molding of the convex portion 55 and the weak area 54 .

[0254] In addition, the first groove portion 53 is formed on the shell component 5 by stamping, which can achieve the purpose of refining the grain of the weak area 54, improve the material mechanical properties of the weak area 54, improve the fatigue strength of the weak area 54, and reduce the risk of the weak area 54 being damaged during normal use of the battery cell 10.

[0255] In some embodiments, please refer to Figures 21-25. Figure 21 is a schematic structural diagram of the shell component 5 (the first groove portion 53 is V-shaped) provided in some embodiments of the present application; Figure 22 is a schematic structural diagram of the shell component 5 (the first groove portion 53 is U-shaped) provided in some embodiments of the present application; Figure 23 is a schematic structural diagram of the shell component 5 (the first groove portion 53 is H-shaped) provided in some embodiments of the present application; Figure 24 is a schematic structural diagram of the shell component 5 (the first groove portion 53 is arc-shaped) provided in some embodiments of the present application; Figure 25 is a schematic structural diagram of the shell component 5 (the first groove portion 53 is annular) provided in some embodiments of the present application. The first groove portion 53 defines a pressure relief area 56, and the first groove portion 53 is arranged along the edge of the pressure relief area 56.

[0256] The pressure relief zone 56 is the area of ​​the outer shell 5 that can be opened after the weak zone 54 is broken. For example, when the pressure inside the battery cell 10 reaches a threshold, the weak zone 54 ruptures, and the pressure relief zone 56 opens outward under the action of the exhaust from the battery cell 10. During this process, the weak zone 54 ruptures along the first groove 53, allowing the pressure relief zone 56 to open with the first groove 53 as the boundary. After the pressure relief zone 56 opens, a discharge port is formed in the outer shell 5 at the position corresponding to the pressure relief zone 56. The exhaust from the battery cell 10 can be discharged through the discharge port, thereby relieving the pressure inside the battery cell 10.

[0257] During pressure relief, the pressure relief zone 56 can be opened with the first groove portion 53 as a boundary, thereby increasing the pressure relief area of ​​the housing component 5 and improving the timeliness of pressure relief.

[0258] In some embodiments, referring to FIG. 21 , the first groove portion 53 includes a first groove section 535 and a second groove section 536 . The first groove section 535 intersects with the second groove section 536 . The first groove section 535 and the second groove section 536 are arranged along the edge of the pressure relief area 56 .

[0259] The first and second slot sections 535, 536 can be straight or non-straight, such as arc-shaped. In embodiments where both the first and second slot sections 535, 536 are straight, it is understood that the first and second slot sections 535, 536 extend along straight lines. The first and second slot sections 535, 536 can be arranged at an acute, right, or obtuse angle. The first and second slot sections 535, 536 can be arranged in a cross-section, such that the intersection of the first and second slot sections 535, 536 is located at the midpoint of the first and second slot sections 535, 536. For example, as shown in FIG21 , the intersection of the first and second slot sections 535, 536 can be located at one end of the first and second slot sections 535, 536, forming a V-shaped structure, thus forming the first slot portion 53 as a V-shaped slot. The triangular shaded area shown in FIG21 represents the pressure relief area 56.

[0260] In this embodiment, stress is more concentrated at the intersection of the first groove section 535 and the second groove section 536, making the weak area 54 at this intersection more easily destroyed. This improves the pressure relief sensitivity of the housing component 5 and allows for timely pressure relief when the internal pressure of the battery cell 10 reaches the detonation pressure. If the detonation pressure of the battery cell 10 is constant, the weak area 54 can be made thicker, reducing the molding depth of the first groove portion 53.

[0261] In some embodiments, please continue to refer to Figures 22 and 23. The first groove portion 53 also includes a third groove section 537. The first groove section 535 is arranged opposite to the third groove section 537. The third groove section 537 intersects with the second groove section 536. The first groove section 535, the second groove section 536 and the third groove section 537 are arranged along the edge of the pressure relief zone 56.

[0262] The first slot section 535, the second slot section 536, and the third slot section 537 can all be linear slots or non-linear slots, such as arc-shaped slots. In an embodiment where the first slot section 535, the second slot section 536, and the third slot section 537 are all linear slots, the first slot section 535, the second slot section 536, and the third slot section 537 all extend along a straight line. The first slot section 535 and the third slot section 537 can be arranged in parallel or at a small non-zero angle, such as an angle of less than 10°. The first slot section 535 and the third slot section 537 can both be perpendicular to the second slot section 536 or non-perpendicular to the second slot section 536. The pressure relief zone 56 defined by the first slot section 535, the second slot section 536, and the third slot section 537 can be one or two.

[0263] In this embodiment, the pressure relief area 56 can be opened with the first groove section 535, the second groove section 536, and the third groove section 537 as the boundary, enabling large-area pressure relief. In addition, the intersection of the third groove section 537 and the second groove section 536 is more concentrated, making it easier to destroy the weak area 54 at the intersection of the third groove section 537 and the second groove section 536. This improves the pressure relief sensitivity of the outer shell component 5 and promptly relieves the pressure when the internal pressure of the battery cell 10 reaches the detonation pressure.

[0264] In some embodiments, please continue to refer to FIG. 22 , the first slot segment 535 , the second slot segment 536 , and the third slot segment 537 are connected in sequence.

[0265] The connection point 533 between the second slot segment 536 and the first slot segment 535 is located at one end of the first slot segment 535 and one end of the second slot segment 536. The connection point 533 between the second slot segment 536 and the third slot segment 537 is located at one end of the third slot segment 537 and the other end of the second slot segment 536. The first, second, and third slot segments 535, 536, 537 can be connected in sequence to form a U-shaped structure or a Z-shaped structure. As an example, in the embodiment shown in FIG22, the first, second, and third slot segments 535, 536, 537 are connected in sequence to form a U-shaped structure, and the first, second, and third slot segments 535, 536, 537 define a pressure relief zone 56. The rectangular shaded area shown in FIG22 is the pressure relief zone 56.

[0266] In this embodiment, the first slot section 535 , the second slot section 536 and the third slot section 537 are connected in sequence. Such a first slot portion 53 has a simple structure and is easy to form.

[0267] 23 , the first slot segment 535 and the second slot segment 536 intersect at a first position 538, which is offset from the ends of the first slot segment 535 in the extension direction. The third slot segment 537 and the second slot segment 536 intersect at a second position 539, which is offset from the ends of the third slot segment 537 in the extension direction.

[0268] The first position 538 is where the first slot segment 535 connects to the second slot segment 536. The first position 538 is offset from both ends of the first slot segment 535 in the extension direction. That is, in the extension direction of the first slot segment 535, there is a distance between the first position 538 and both ends of the first slot segment 535. The second position 539 is where the third slot segment 537 connects to the second slot segment 536. The second position 539 is offset from both ends of the third slot segment 537 in the extension direction. That is, in the extension direction of the third slot segment 537, there is a distance between the second position 539 and both ends of the third slot segment 537.

[0269] The first slot section 535, the second slot section 536 and the third slot section 537 define two pressure relief areas 56, which are located on both sides of the second slot section 536. The two rectangular shaded areas shown in FIG23 are both pressure relief areas 56.

[0270] During pressure relief, the two pressure relief areas 56 can be opened in a split manner to relieve pressure, which can effectively improve the pressure relief efficiency of the outer shell component 5 .

[0271] In some embodiments, referring to FIG. 23 , the first position 538 is located at the midpoint of the first slot segment 535 in the extension direction, and the second position 539 is located at the midpoint of the third slot segment 537 in the extension direction.

[0272] As an example, the first slot segment 535, the second slot segment 536, and the third slot segment 537 are all linear slots extending along a straight trajectory. The first slot segment 535 and the third slot segment 537 are arranged in parallel, perpendicular to each other, and have equal lengths. The two pressure relief areas 56 are symmetrically distributed on either side of the second slot segment 536.

[0273] In this embodiment, the first position 538 and the second position 539 are located at the midpoints of the first slot section 535 and the third slot section 537, respectively. The weak area 54 is more easily destroyed at the first position 538 and the second position 539, thereby improving the pressure relief sensitivity of the shell component 5 and improving the timeliness of pressure relief.

[0274] In some embodiments, please continue to refer to FIG. 24 , the first groove portion 53 is a groove extending along a non-closed track.

[0275] A non-closed trajectory refers to a trajectory whose two ends are not connected in the extension direction. The non-closed trajectory can be an arc trajectory, a U-shaped trajectory, a Z-shaped trajectory, etc.

[0276] The pressure relief area 56 defined by the first groove portion 53 can be opened in a flipping manner. After opening, the pressure relief area 56 can eventually be connected to other areas of the housing component 5, reducing the risk of splashing after the pressure relief area 56 is opened.

[0277] In some embodiments, please continue to refer to FIG. 24 , the first groove portion 53 is an arc-shaped groove.

[0278] A circular arc groove is a groove extending along a circular arc trajectory, which is a non-closed trajectory. The central angle of the circular arc groove can be less than, equal to, or greater than 180°. As an example, in the embodiment shown in Figure 24, the central angle of the circular arc groove is 180°, and the pressure relief area 56 defined by the circular arc groove is semicircular.

[0279] The arc-shaped groove has a simple structure and is easy to form. During the pressure relief process, the pressure relief area 56 can be quickly broken along the arc-shaped groove so that the pressure relief area 56 is quickly opened.

[0280] In some embodiments, please continue to refer to FIG. 25 , the first groove portion 53 is a groove extending along a closed track.

[0281] A closed trajectory refers to a trajectory that is connected at both ends. A closed trajectory can be a circular trajectory, a rectangular trajectory, an elliptical trajectory, etc.

[0282] During the pressure relief process, the shell component 5 can rupture along the first groove portion 53 , so that the pressure relief zone 56 can be opened in a detached manner, thereby increasing the pressure relief area of ​​the shell component 5 and improving the pressure relief rate of the shell component 5 .

[0283] In some embodiments, the first groove portion 53 is an annular groove.

[0284] The annular groove can be a rectangular annular groove, a circular annular groove, etc.

[0285] As an example, in FIG25 , the first groove portion 53 is a generally rectangular annular groove. The first groove portion 53 comprises two straight segments and two arc segments. The two straight segments are arranged in parallel, with one straight segment, one arc segment, another straight segment, and another arc segment connected end to end. The spacing between the two straight segments is less than the minimum spacing between the two arc segments.

[0286] In this embodiment, the annular groove has a simple structure and is easy to form. During the pressure relief process, the shell component 5 can be quickly broken along the annular groove to quickly open the pressure relief area 56.

[0287] In some embodiments, please refer to Figures 26-28. Figure 26 is an isometric view of the housing component 5 provided in some embodiments of the present application; Figure 27 is a schematic structural diagram of the housing component 5 shown in Figure 26 (showing the first groove portion 53 and the second groove portion 57); and Figure 28 is a JJ cross-sectional view of the housing component 5 shown in Figure 27. The housing component 5 is provided with a second groove portion 57, extending from the first surface 51 toward the second surface 52. The second groove portion 57 and the first groove portion 53 are provided in sequence, and the bottom surface of the second groove portion 57 forms the first surface 51.

[0288] The second groove 57 and the first groove 53 may have the same or different shapes. It is understood that the housing 5 is provided with at least two levels of grooves, such as two, three, four, or more. Along the first direction Z, the two grooves closest to the second surface 52 of the at least two levels are the first groove 53 and the second groove 57, respectively.

[0289] The groove bottom surface of the second groove portion 57 forms the first surface 51 . That is, the first groove portion 53 is recessed from the groove bottom surface of the second groove portion 57 in a direction approaching the second surface 52 .

[0290] In this embodiment, the first groove portion 53 can be a groove of various shapes, such as a V-shaped groove, a U-shaped groove, an H-shaped groove, an arc-shaped groove, an annular groove, etc. As an example, in the embodiment shown in Figures 26 to 28, the first groove portion 53 is an H-shaped groove.

[0291] As an example, as shown in FIG28 , the housing component 5 further includes a third surface 58, which is disposed opposite the second surface 52 along the first direction Z. The distance between the third surface 58 and the second surface 52 is greater than the distance between the first surface 51 and the second surface 52. The second groove 57 is recessed from the third surface 58 in a direction facing the second surface 52. The housing component 5 is provided with only the first groove 53 and the second groove 57 at locations corresponding to the weak areas 54.

[0292] In an embodiment where the outer shell component 5 is an end cover 12, the distance between the third surface 58 and the second surface 52 may be the thickness of the end cover 12, the third surface 58 may be the outer surface of the end cover 12, the second surface 52 may be the inner surface of the end cover 12, and the inner surface of the end cover 12 faces the interior of the battery cell 10; in an embodiment where the outer shell component 5 is a shell 11, the distance between the third surface 58 and the second surface 52 may be the wall thickness of the shell 11, the third surface 58 may be the outer surface of a wall portion of the shell 11, and the second surface 52 may be the inner surface of the wall portion of the shell 11.

[0293] During molding, the second groove 57 can be formed on the housing component 5 first, and then the first groove 53 can be formed on the housing component 5 to form the weak area 54. In other words, by forming at least two levels of grooves on the housing component 5 before forming the weak area 54, the molding depth of each level of grooves can be reduced, thereby reducing the molding force on the housing component 5 during molding and reducing the risk of cracks in the housing component 5.

[0294] In some embodiments, please continue to refer to Figures 26 to 28. The first groove portion 53 and the pressure relief area 56 are both located on the groove bottom wall 571 of the second groove portion.

[0295] The second groove bottom wall 571 is the portion of the housing 5 located between the bottom surface of the second groove 57 and the second surface 52. After the second groove 57 is formed on the housing 5, the remaining portion of the housing 5 in the area where the second groove 57 is located serves as the second groove bottom wall 571. The pressure relief area 56 may be a portion of the second groove bottom wall 571.

[0296] When the pressure relief area 56 opens into the second groove 57, the second groove 57 can provide a clearance space for the pressure relief area 56. For example, when the third surface 58 is blocked by an obstacle, the second groove 57 provides a clearance space for the pressure relief area 56, reducing the impact of the obstacle on the pressure relief area 56 and allowing the pressure relief area 56 to open normally.

[0297] In some embodiments, the cross section of the second groove portion 57 perpendicular to the first direction Z is polygonal or circular.

[0298] The polygonal shape may be a triangle, quadrilateral, pentagon, hexagon, etc. The second groove portion 57 may be a polygonal prism groove with a polygonal cross section, a cylindrical groove with a circular cross section, or a stepped groove with a polygonal or circular cross section, the cross section being perpendicular to the first direction Z.

[0299] As an example, in the embodiments shown in FIG. 26 to FIG. 28 , the second groove portion 57 is a quadrangular prism groove having a quadrilateral cross section.

[0300] In this embodiment, the cross-section of the second groove portion 57 perpendicular to the first direction Z is polygonal or circular. The second groove portion 57 of this structure is simple in structure and easy to form, and can provide more avoidance space for the pressure relief zone 56 during the opening process.

[0301] In some embodiments, please refer to Figures 29 and 30. Figure 29 is a schematic structural diagram of the housing component 5 (both the first groove 53 and the second groove 57 are H-shaped grooves) provided in some embodiments of the present application; Figure 30 is a KK cross-sectional view of the housing component 5 shown in Figure 29. The extension direction of the second groove 57 is consistent with the extension direction Y of the first groove.

[0302] As an example, as shown in Figures 29 and 30, the first slot portion 53 extends along an H-shaped trajectory, and the second slot portion 57 also extends along an H-shaped trajectory. The first slot portion 53 and the second slot portion 57 are both H-shaped slots. Each slot segment in the second slot portion 57 extends in the same direction as the corresponding slot segment in the first slot portion 53.

[0303] It can be understood that, in the embodiment where the first groove portion 53 is a V-shaped groove, the second groove portion 57 is also a V-shaped groove; in the embodiment where the first groove portion 53 is a U-shaped groove, the second groove portion 57 is also a U-shaped groove; in the embodiment where the first groove portion 53 is a circular arc groove, the second groove portion 57 is also a circular arc groove; in the embodiment where the first groove portion 53 is an annular groove, the second groove portion 57 is also an annular groove.

[0304] The extension direction of the second groove portion 57 is consistent with the extension direction Y of the first groove portion, so that the shape of the second groove portion 57 is substantially the same as that of the first groove portion 53, which facilitates the molding of the second groove portion 57. When the first groove portion 53 and the second groove portion 57 are molded by stamping, the amount of material extruded during the molding of the second groove portion 57 can be reduced, thereby reducing the molding force applied to the housing component 5.

[0305] In some embodiments, please refer to Figures 31 and 32. Figure 31 is a schematic structural diagram of a housing component 5 (illustrating a first groove 53, a second groove 57, and a third groove 59) provided in some embodiments of the present application; Figure 32 is a cross-sectional view taken along a line MM of the housing component 5 shown in Figure 31. The housing component 5 is provided with a third groove 59, and the second groove 57 is provided at the bottom surface of the third groove 59. The first groove 53, the second groove 57, and the pressure relief area 56 are all located at the bottom wall 591 of the third groove.

[0306] The third groove bottom wall 591 is the portion of the housing component 5 located between the bottom surface of the third groove 59 and the second surface 52. After the third groove 59 is formed in the housing component 5, the remaining portion of the housing component 5 in the area where the third groove 59 is located serves as the third portion's bottom wall 121b. The pressure relief area 56 may be a portion of the third groove bottom wall 591.

[0307] It is understood that the housing member 5 is provided with at least three levels of grooves, for example, three levels of grooves, four levels of grooves, five levels of grooves, or more. Along the first direction Z, the three levels of grooves closest to the second surface 52 of the at least three levels of grooves are respectively the first groove 53, the second groove 57, and the third groove 59.

[0308] As an example, as shown in FIG32 , the housing component 5 further includes a third surface 58, which is disposed opposite the second surface 52 along the first direction Z. The distance between the third surface 58 and the second surface 52 is greater than the distance between the first surface 51 and the second surface 52. A third groove 59 is recessed from the third surface 58 in a direction facing the second surface 52. The second groove 57 is recessed from the bottom surface of the third groove 59 in a direction facing the second surface 52. The first groove 53 is recessed from the bottom surface of the second groove 57 in a direction facing the second surface 52. The housing component 5 is provided with only the first groove 53, the second groove 57, and the third groove 59 at locations corresponding to the weak areas 54.

[0309] In an embodiment where the outer shell component 5 is an end cover 12, the distance between the third surface 58 and the second surface 52 may be the thickness of the end cover 12, the third surface 58 may be the outer surface of the end cover 12, the second surface 52 may be the inner surface of the end cover 12, and the inner surface of the end cover 12 faces the interior of the battery cell 10; in an embodiment where the outer shell component 5 is a shell 11, the distance between the third surface 58 and the second surface 52 may be the wall thickness of the shell 11, the third surface 58 may be the outer surface of a wall portion of the shell 11, and the second surface 52 may be the inner surface of the wall portion of the shell 11.

[0310] During molding, the third groove 59 can be formed on the housing component 5 first, followed by the second groove 57, and finally the first groove 53, to form the weak zone 54. In other words, by forming at least three levels of grooves on the housing component 5 before forming the weak zone 54, the molding depth of each level of grooves can be reduced, thereby reducing the molding force applied to the housing component 5 during molding and lowering the risk of cracks in the housing component 5. Furthermore, because the pressure relief zone 56 is located on the bottom wall 591 of the third groove, when the pressure relief zone 56 opens into the third groove 59, the third groove 59 provides a clearance for the pressure relief zone 56.

[0311] In some embodiments, the cross section of the third groove portion 59 perpendicular to the first direction Z is polygonal or circular.

[0312] The polygonal shape may be a triangle, quadrilateral, pentagon, hexagon, etc. The second groove portion 57 may be a polygonal prism groove with a polygonal cross section, a cylindrical groove with a circular cross section, or a stepped groove with a polygonal or circular cross section, the cross section being perpendicular to the first direction Z.

[0313] As an example, in the embodiment shown in FIG. 31 and FIG. 32 , the second groove portion 57 is a quadrangular prism groove having a quadrilateral cross section.

[0314] In this embodiment, the cross-section of the third groove portion 59 perpendicular to the first direction Z is polygonal or circular. The third groove portion 59 of this structure is simple in structure and easy to form, and can provide more avoidance space for the pressure relief zone 56 during the opening process.

[0315] It should be noted that, in other embodiments, the shell component 5 may also be provided with a third groove portion 59, and the second groove portion 57 may be provided on the bottom surface of the third groove portion 59, and the extension directions of the third groove portion 59 and the second groove portion 57 are consistent with the extension direction Y of the first groove portion.

[0316] In some embodiments, please refer to FIG33 , which is a schematic diagram of the structure of the end cap 12 provided in some embodiments of the present application. The housing component 5 is the end cap 12 , which is used to close the opening of the housing 11 , which is used to accommodate the electrode assembly 2 .

[0317] The end cap 12 may be a plate-like structure such as a circular or rectangular structure. As an example, in the embodiment shown in FIG33 , the end cap 12 is a rectangular plate-like structure.

[0318] In this embodiment, the end cap 12 has a pressure relief function, thereby improving the reliability of the battery cell 10. In addition, the end cap 12 serves as the outer shell component 5, making it easier to form the weak area 54 on the end cap 12.

[0319] In some embodiments, the second surface 52 is a surface of the end cap 12 facing the interior of the housing 11 .

[0320] The first surface 51 and the second surface 52 are two opposing surfaces of the end cap 12 along the first direction Z. The second surface 52 may be the surface of the end cap 12 farthest from the first surface 51 along the first direction Z. The second surface 52 is the inner surface of the end cap 12. The first direction Z is the thickness direction of the end cap 12. It is understood that in embodiments where only the first groove 53 is provided in the end cap 12, the first surface 51 is the outer surface of the end cap 12; in embodiments where only the first groove 53 and the second groove 57 are provided in the end cap 12, the third surface 58 is the outer surface of the end cap 12; and in embodiments where only the first groove 53, the second groove 57, and the third groove 59 are provided in the end cap 12, the third surface 58 is the outer surface of the end cap 12.

[0321] In this embodiment, the second surface 52 is the surface of the end cover 12 facing the interior of the housing 11 , and the protrusion 55 protruding from the second surface 52 is located inside the housing 11 , effectively utilizing the internal space of the housing 11 .

[0322] In some embodiments, please refer to Figures 34 and 35. Figure 34 is a schematic structural diagram of the housing 11 provided in some embodiments of the present application; Figure 35 is a cross-sectional view of the housing 11 provided in other embodiments of the present application. The outer shell component 5 is the housing 11, which has an opening and is used to accommodate the electrode assembly 2.

[0323] The housing 11 of the housing 1 is the housing component 5, and the end cap 12 of the housing 1 is used to close the opening of the housing 11. The housing 11 can be a hollow structure with an opening at one end, or a hollow structure with openings at two opposite ends. The housing 11 can be a rectangular parallelepiped, a cylinder, etc.

[0324] In this embodiment, the housing 1 has a pressure relief function, so that the battery cell 10 has good reliability.

[0325] In some embodiments, the housing 11 includes a plurality of integrally formed wall portions 121 , which together define an interior space of the housing 11 , and at least one of the wall portions 121 is formed with a weak area 54 .

[0326] In the shell 11 , a first groove portion 53 may be provided on one wall portion 121 to form a corresponding weak area 54 ; or first groove portions 53 may be provided on multiple wall portions 121 to form a corresponding weak area 54 on each wall portion 121 where the first groove portion 53 is provided.

[0327] For the wall portion 121 provided with the first groove portion 53, the first surface 51 and the second surface 52 are two surfaces of the wall portion 121 that are opposite to each other along the first direction Z. The first direction Z is the thickness direction of the wall portion 121 formed with the weak area 54. The first surface 51 may face the interior of the housing 11, and the second surface 52 may face away from the interior of the housing 11; alternatively, the second surface 52 may face the interior of the housing 11, and the first surface 51 may face away from the interior of the housing 11.

[0328] In this embodiment, the plurality of wall portions 121 are integrally formed, the housing 11 has good structural stability, and the wall portions 121 are not easily damaged when the weak areas 54 are formed.

[0329] In some embodiments, please continue to refer to Figures 34 and 35, the multiple wall portions 121 include a bottom wall 121b and multiple side walls 121a surrounding the bottom wall 121b, and the shell 11 forms an opening at the end opposite to the bottom wall 121b; the bottom wall 121b is formed with a weak area 54; and / or, at least one side wall 121a is formed with a weak area 54.

[0330] It is understandable that the housing 11 is a hollow structure with an opening formed at one end.

[0331] The housing 11 may have three, four, five, six, or more side walls 121a. In the housing 11, a portion of the side walls 121a may be formed with the weakened area 54, or all of the side walls 121a may be formed with the weakened area 54. For example, if the housing 11 has four side walls 121a, one, two, three, or four side walls 121a may be formed with the weakened area 54.

[0332] As an example, in the embodiment shown in Figure 34, there are four side walls 121a in the shell 11, and only one side wall 121a is formed with a weak area 54; in the embodiment shown in Figure 35, only the bottom wall 121b of the shell 11 is formed with a weak area 54, and the side wall 121a is not formed with a weak area 54.

[0333] For the battery cell 10, if the bottom wall 121b of the shell 11 is formed with a weak area 54, when the battery cell 10 thermally runs away, pressure can be released through the bottom wall 121b; if at least one side wall 121a is formed with a weak area 54, when the battery cell 10 thermally runs away, pressure can be released through the side wall 121a.

[0334] In some embodiments, the second surface 52 is the surface of the wall portion 121 provided with the weak area 54 facing the interior of the housing 11 .

[0335] For the wall portion 121 provided with the weakened area 54, the first surface 51 and the second surface 52 are two surfaces of the wall portion 121 that are opposite each other along the first direction Z. The second surface 52 may be the surface of the wall portion 121 that is farthest from the first surface 51 along the first direction Z. The second surface 52 is the inner surface of the wall portion 121. It is understood that in an embodiment in which only the first groove portion 53 is provided in the wall portion 121, the first surface 51 is the outer surface of the wall portion 121; in an embodiment in which only the first groove portion 53 and the second groove portion 57 are provided in the wall portion 121, the third surface 58 is the outer surface of the wall portion 121; and in an embodiment in which only the first groove portion 53, the second groove portion 57, and the third groove portion 59 are provided in the wall portion 121, the third surface 58 is the outer surface of the wall portion 121.

[0336] In this embodiment, the second surface 52 is the surface of the wall portion 121 provided with the weak area 54 facing the interior of the shell 11 , and the protrusion 55 protruding from the second surface 52 is located inside the shell 11 , effectively utilizing the internal space of the shell 11 .

[0337] In some embodiments, referring to Figures 34 and 35 , the housing 11 is a rectangular parallelepiped, which is suitable for rectangular parallelepiped battery cells 10 and can meet the large capacity requirements of the battery cells 10 .

[0338] In some embodiments, the material of the housing component 5 includes aluminum alloy.

[0339] It is understandable that, in the embodiment where the housing component 5 is the end cover 12 , the material of the end cover 12 may be aluminum alloy; and in the embodiment where the housing component 5 is the shell 11 , the material of the shell 11 may be aluminum alloy.

[0340] The housing component 5 made of aluminum alloy is light in weight, has good ductility and is easy to form.

[0341] An embodiment of the present application provides a battery cell 10 , comprising the housing component 5 provided in any one of the above embodiments.

[0342] In some embodiments, the battery cell 10 further includes a housing 11 having an opening for accommodating the electrode assembly 2. The outer shell component 5 is an end cap 12, which closes the opening.

[0343] In some embodiments, the housing component 5 is a shell 11 having an opening, and the shell 11 is used to accommodate the electrode assembly 2. The battery cell 10 further includes an end cap 12, which closes the opening.

[0344] An embodiment of the present application provides a battery 100 , comprising the battery cell 10 provided in any one of the above embodiments.

[0345] An embodiment of the present application provides an electrical device, comprising a battery cell 10 provided by any one of the above embodiments, wherein the battery cell 10 is used to provide electrical energy.

[0346] In some embodiments, the present application provides an end cap 12 for use with a battery cell 10. The end cap 12 has a first surface 51 and a second surface 52. The first surface 51 and the second surface 52 are arranged opposite each other along the thickness direction of the end cap 12. The first surface 51 is the outer surface of the end cap 12, and the second surface 52 is the inner surface of the end cap 12, which faces the interior of the battery cell 10. The end cap 12 is provided with a first groove 53 that is recessed from the first surface 51 toward the second surface 52. The end cap 12 forms a weak area 54 at the bottom of the first groove 53. The weak area 54 is configured to be destroyed when the internal pressure of the battery cell 10 is released. Along the first direction Z, a protrusion 55 is provided on the side of the weak area 54 facing away from the first groove 53, protruding from the second surface 52. The extension direction of the protrusion 55 is consistent with the extension direction Y of the first groove.

[0347] Along the first direction Z, the first groove portion 53 includes a first groove bottom surface 531 located between the first surface 51 and the second surface 52. The outer surface of the protrusion 55 is connected to the second surface 52 to form a first contour line 551. The first contour line 551 defines a first region. The projection of the edge line 5311 of the first groove bottom surface 531 along the first direction Z lies within the first region and does not contact the first contour line 551. The area of ​​the first region is S1, and the area of ​​the portion of the projection of the first region along the first direction Z located within the first groove portion 53 is S2, where S2 / S1 ≥ 0.6. The minimum distance between the first groove bottom surface 531 and the second surface 52 is D. The height of the protrusion 55 protruding from the second surface 52 is H, where 0.03 ≤ H / (D+H) ≤ 0.33, and 0.05 mm ≤ H ≤ 0.55 mm. The first groove portion 53 includes a first groove bottom surface 531 and a first groove side surface 532 connected to the first groove bottom surface 531. The angle between the first groove side surface 532 and the first groove bottom surface 531 is θ, measured in degrees. The first groove side surface 532 is connected to the first groove bottom surface 531 at a connection position 533. Along the first direction Z, the minimum residual thickness of the shell component 5 at the connection position 533 is L, measured in mm. 90≤θ / L≤5833.

[0348] In some embodiments, the present application provides a housing 11 for a battery cell 10. The housing 11 is a rectangular parallelepiped housing with an opening at one end. The housing 11 includes multiple integrally formed walls 121. The multiple walls 121 collectively define the interior space of the housing 11. At least one wall 121 has a weakened area 54. The wall 121 having the weakened area 54 has a first surface 51 and a second surface 52. The first and second surfaces 51 and 52 are disposed opposite each other along the thickness of the wall 121. The first surface 51 is the outer surface of the wall 121, and the second surface 52 is the inner surface of the wall 121, which faces the interior of the battery cell 10. The wall 121 has a first groove 53 recessed from the first surface 51 toward the second surface 52. The wall 121 forms a weakened area 54 at the bottom of the first groove 53. The weakened area 54 is configured to be destroyed when the internal pressure of the battery cell 10 is released. Along the first direction Z, a protrusion 55 protruding from the second surface 52 is provided on a side of the weak area 54 away from the first groove 53. The extending direction of the protrusion 55 is consistent with the extending direction Y of the first groove.

[0349] Along the first direction Z, the first groove portion 53 includes a first groove bottom surface 531 located between the first surface 51 and the second surface 52. The outer surface of the protrusion 55 is connected to the second surface 52 to form a first contour line 551. The first contour line 551 defines a first region. The projection of the edge line 5311 of the first groove bottom surface 531 along the first direction Z lies within the first region and does not contact the first contour line 551. The area of ​​the first region is S1, and the area of ​​the portion of the projection of the first region along the first direction Z located within the first groove portion 53 is S2, where S2 / S1 ≥ 0.6. The minimum distance between the first groove bottom surface 531 and the second surface 52 is D. The height of the protrusion 55 protruding from the second surface 52 is H, where 0.03 ≤ H / (D+H) ≤ 0.33, and 0.05 mm ≤ H ≤ 0.55 mm. The first groove portion 53 includes a first groove bottom surface 531 and a first groove side surface 532 connected to the first groove bottom surface 531. The angle between the first groove side surface 532 and the first groove bottom surface 531 is θ, measured in degrees. The first groove side surface 532 is connected to the first groove bottom surface 531 at a connection position 533. Along the first direction Z, the minimum residual thickness of the shell component 5 at the connection position 533 is L, measured in mm. 90≤θ / L≤5833.

[0350] 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.

[0351] 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 housing component for a battery cell, the housing component comprising a first surface and a second surface, the first surface and the second surface being arranged opposite to each other along a first direction, the housing component being provided with a first groove portion recessed from the first surface in a direction close to the second surface; The housing component forms a weak area at the bottom of the first groove, and the weak area is configured to be destroyed when the battery cell releases internal pressure. Along the first direction, a side of the weak area away from the first groove is provided with a convex portion protruding from the second surface.

2. The housing component according to claim 1, wherein: Along the first direction, the first groove portion includes a first groove bottom surface located between the first surface and the second surface, the minimum distance between the first groove bottom surface and the second surface is D, the height of the protrusion protruding from the second surface is H, 0.01≤H / (D+H)≤0.

67.

3. The housing component according to claim 1 or 2, wherein: 0.03≤H / (D+H)≤0.

33.

4. The housing component according to any one of claims 1 to 3, wherein: Along the first direction, the height of the protrusion protruding from the second surface is H, and 0.01 mm≤H≤0.96 mm.

5. The housing component according to claim 4, wherein: 0.05mm≤H≤0.55mm.

6. The housing component according to any one of claims 1 to 5, wherein: The first groove portion includes a first groove bottom surface and a first groove side surface connected to the first groove bottom surface, the angle between the first groove side surface and the first groove bottom surface is θ, measured in degrees; the first groove side surface is connected to the first groove bottom surface at a connection position, and along the first direction, the minimum residual thickness of the shell component at the connection position is L, measured in mm; 90≤θ / L≤5833.

7. The housing component according to claim 6, wherein: 220≤θ / L≤933.

8. The housing component according to claim 6 or 7, wherein: 90°≤θ≤175°.

9. The housing component according to any one of claims 6 to 8, wherein: 0.03mm≤L≤1mm.

10. The housing component according to any one of claims 1 to 9, wherein: Along the first direction, the first groove portion includes a first groove bottom surface located between the first surface and the second surface; The outer surface of the protrusion is connected to the second surface to form a first contour line, and the projection of the first contour line along the first direction is located within the bottom surface of the first groove.

11. The housing component according to claim 10, wherein: The projection of the first contour line along the first direction in the first groove bottom surface coincides with the edge line of the first groove bottom surface.

12. The housing component according to claim 10, wherein: A projection of the first contour line along the first direction does not contact an edge line of the first groove bottom surface within the first groove bottom surface.

13. The housing component according to any one of claims 1 to 9, wherein: Along the first direction, the first groove portion includes a first groove bottom surface located between the first surface and the second surface; The outer surface of the protrusion is connected to the second surface to form a first contour line, the first contour line defines a first area, and the projection of the edge line of the bottom surface of the first groove along the first direction is located in the first area and does not contact the first contour line.

14. The housing component according to any one of claims 1 to 13, wherein: The outer surface of the convex portion is connected to the second surface to form a first contour line, the first contour line defines a first region, the area of ​​the first region is S1, the area of ​​the projection of the first region along the first direction located in the first groove is S2, S2 / S1≥0.

6.

15. The housing component according to any one of claims 1 to 14, wherein: Along the first direction, a surface of the protrusion facing away from the second surface is a plane.

16. The housing component according to any one of claims 1 to 14, wherein: Along the first direction, the surface of the convex portion away from the second surface is an arc surface, and the cross section of the arc surface is an arc line convex in the middle position along the direction away from the second surface.

17. The housing component according to any one of claims 1 to 16, wherein: An extending direction of the convex portion is consistent with an extending direction of the first groove portion.

18. The housing component according to any one of claims 1 to 17, wherein: The convex portion and the weak area are integrally formed.

19. The housing component according to any one of claims 1 to 18, wherein: The first groove portion is stamped and formed on the housing component.

20. The housing component according to any one of claims 1 to 19, wherein: The first groove portion defines a pressure relief area, and the first groove portion is arranged along an edge of the pressure relief area.

21. The housing component of claim 20, wherein: The first slot portion includes a first slot segment and a second slot segment, the first slot segment intersects with the second slot segment, and the first slot segment and the second slot segment are arranged along the edge of the pressure relief area.

22. The housing component of claim 21, wherein: The first slot portion further includes a third slot section, the first slot section is arranged opposite to the third slot section, the third slot section intersects with the second slot section, and the first slot section, the second slot section and the third slot section are arranged along the edge of the pressure relief zone.

23. The housing component of claim 22, wherein: The first slot section, the second slot section and the third slot section are connected in sequence.

24. The housing component of claim 22, wherein: The first slot segment intersects with the second slot segment at a first position, and the first position deviates from the two ends of the first slot segment in the extension direction; the third slot segment intersects with the second slot segment at a second position, and the second position deviates from the two ends of the third slot segment in the extension direction.

25. The housing component of claim 24, wherein: The first position is located at the midpoint of the first slot segment in the extension direction, and the second position is located at the midpoint of the third slot segment in the extension direction.

26. The housing component of claim 20, wherein: The first groove portion is a groove extending along a non-closed track.

27. The housing component of claim 26, wherein: The first groove portion is an arc-shaped groove.

28. The housing component of claim 20, wherein: The first groove portion is a groove extending along a closed track.

29. The housing component of claim 28, wherein: The first groove portion is an annular groove.

30. A housing component according to any one of claims 20 to 29, wherein: The housing component is provided with a second groove portion, and the second groove portion and the first groove portion are arranged in sequence along a direction pointing from the first surface to the second surface, and a groove bottom surface of the second groove portion forms the first surface.

31. The housing component of claim 30, wherein: The first groove portion and the pressure relief area are both located on the groove bottom wall of the second groove portion.

32. The housing component of claim 31, wherein: A cross section of the second groove portion perpendicular to the first direction is polygonal or circular.

33. The housing component of claim 30, wherein: An extending direction of the second groove portion is consistent with an extending direction of the first groove portion.

34. The housing component of claim 33, wherein: The housing component is provided with a third groove portion, and the second groove portion is provided on the groove bottom surface of the third groove portion; The first groove portion, the second groove portion and the pressure relief area are all located on the groove bottom wall of the third groove portion.

35. The housing component of claim 34, wherein: A cross section of the third groove portion perpendicular to the first direction is polygonal or circular.

36. A housing component as claimed in any one of claims 1 to 35, wherein: The shell component is an end cover, which is used to close the opening of the shell, and the shell is used to accommodate the electrode assembly.

37. The housing component of claim 36, wherein: The second surface is a surface of the end cover facing the interior of the housing.

38. A housing component as claimed in any one of claims 1 to 35, wherein: The housing component is a shell having an opening and is used to accommodate the electrode assembly.

39. The housing component of claim 38, wherein: The shell includes a plurality of integrally formed wall portions, the plurality of wall portions jointly define an internal space of the shell, and at least one of the wall portions is formed with the weak area.

40. The housing component of claim 39, wherein: The plurality of wall portions include a bottom wall and a plurality of side walls surrounding the bottom wall, and the shell forms the opening at one end opposite to the bottom wall; The bottom wall is formed with the weakened area; and / or At least one of the side walls is formed with the weakened area.

41. A housing component as claimed in claim 39 or 40, wherein: The second surface is a surface of the wall portion provided with the weak area facing the interior of the housing.

42. A housing component as claimed in any one of claims 38 to 41, wherein: The shell is a cuboid.

43. A housing component as claimed in any one of claims 1 to 42, wherein: The material of the housing component includes aluminum alloy.

44. A battery cell comprising the housing component according to any one of claims 1 to 43.

45. The battery cell according to claim 44, wherein: The battery cell further comprises a shell having an opening, and the shell is used to accommodate the electrode assembly; The housing component is an end cover, and the end cover closes the opening.

46. ​​The battery cell according to claim 44, wherein: The housing component is a shell having an opening, and the shell is used to accommodate the electrode assembly; The battery cell further includes an end cover that closes the opening.

47. A battery comprising the battery cell according to any one of claims 44 to 46.

48. An electrical device comprising a battery cell as claimed in any one of claims 44 to 46, wherein the battery cell is used to provide electrical energy.

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