Battery cell, battery, and electric device

Abstract

Provided in the embodiments of the present application are a battery cell, a battery, and an electric device. The battery cell comprises: a casing and a pressure relief component, wherein the pressure relief component is arranged on a first wall portion of the casing. The pressure relief component is provided with a first groove and a second groove, the first groove defining at least one predetermined pressure relief region; the pressure relief component is configured to crack along at least part of the first groove during pressure relief of the battery cell; and the pressure relief component is provided with a first surface and a second surface opposite each other, the second groove being arranged on the first surface and used for guiding at least part of the predetermined pressure relief region to turn over. The second groove comprises a first groove side face and a second groove side face arranged opposite each other, the first groove side face being closer to the predetermined pressure relief region than the second groove side face, and the angle formed between the first groove side face and the first surface being smaller than the angle formed between the second groove side face and the first surface. Thus, the risk of the predetermined pressure relief region being opened prematurely due to a poor level of surface flatness can be reduced, thereby prolonging the service life of the battery cell.

Description

Battery cells, batteries and electrical equipment Technical Field

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

[0002] 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 components. In the event of thermal runaway, these components release internal pressure to improve reliability. Battery technology not only considers the reliability of battery cells, but also their service life. Therefore, increasing the service life of battery cells is a pressing issue in battery technology.

[0004] Summary of the Invention

[0005] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can effectively improve the surface flatness of a pressure relief component.

[0006] In the first aspect, an embodiment of the present application provides a battery cell, comprising a shell and a pressure relief component, the shell comprising a first wall portion, the pressure relief component being arranged on the first wall portion; the pressure relief component being provided with a first groove and a second groove, the first groove defining at least one predetermined pressure relief area, the pressure relief component being configured to be able to split along at least a portion of the first groove when the battery cell is pressure-relieved, and along the thickness direction of the first wall portion, the pressure relief component having a first surface and a second surface relative to each other, the second groove being recessed from the first surface toward a direction close to the second surface, the second groove being configured to guide at least a portion of the predetermined pressure relief area to flip over so as to open at least a portion of the predetermined pressure relief area; wherein, along the width direction of the second groove, the second groove comprises a first groove side surface and a second groove side surface which are oppositely arranged and connected to the first surface, the first groove side surface being closer to the predetermined pressure relief area than the second groove side surface, the angle between the first groove side surface and the first surface being a, the angle between the second groove side surface and the first surface being b, satisfying: 90°≤a<b<180°, and the width direction of the second groove being perpendicular to the thickness direction of the first wall portion.

[0007] In the above technical solution, the pressure relief component is provided with a first groove, which defines at least one predetermined pressure relief area. When the pressure of the battery cell is released, the pressure relief component can split along at least a portion of the first groove to open the predetermined pressure relief area and release the internal pressure of the battery cell. The pressure relief component is also provided with a second groove, which can guide at least a portion of the predetermined pressure relief area to flip, thereby opening at least a portion of the predetermined pressure relief area for pressure relief. The second groove assists the predetermined pressure relief area, making it easier to flip the predetermined pressure relief area, reducing the difficulty of flipping the predetermined pressure relief area, and allowing the predetermined pressure relief area to open more quickly during the process of the pressure relief component splitting along the first groove, thereby increasing the opening rate of the predetermined pressure relief area. In addition, since 90°≤a<b<180°, it is equivalent to reducing the angle between the side of the first groove and the first surface, which can reduce the amount of excess material squeezed out when forming the second groove and diffusing to the predetermined pressure relief area, and reduce the height of the pile bulge formed by the accumulation of excess material squeezed out from the area where the second groove of the pressure relief component is set in the predetermined pressure relief area, thereby improving the flatness of the surface of the predetermined pressure relief area, reducing the risk of the predetermined pressure relief area opening prematurely due to poor surface flatness, and improving the service life of the battery cell.

[0008] In some embodiments, 90°≤a≤150°. This reduces the impact of the side surface of the first groove on the molding tool, making it easier to remove the molding tool from the second groove, and reducing the difficulty of molding the second groove.

[0009] In some embodiments, 90°<b≤170°, which reduces the impact of the side surface of the second groove on the molding tool, making it easier to remove the molding tool from the second groove, and reducing the difficulty of molding the second groove.

[0010] In some embodiments, the second groove further includes a first groove bottom surface, which connects the first groove side surface and the second groove side surface. The second groove forms a first notch on the first surface. Along the width direction of the second groove, the width of the first groove bottom surface is L1, and the width of the first notch is L2, satisfying the following: L1 < L2. This makes the second groove have a structure with a wide top and a narrow bottom, which facilitates the removal of a molding tool used to form the second groove from the second groove, thereby facilitating the molding of the second groove.

[0011] In some embodiments, 0.05mm≤L1≤0.3mm; L1≥0.05mm ensures that the bottom surface of the second groove has sufficient width. This reduces the difficulty of forming the second groove and reduces the risk of stress concentration resulting from an excessively narrow bottom surface of the second groove, which could lead to insufficient strength in the remaining portion of the second groove. When L1≤0.3mm, the bottom surface of the second groove is not too wide, reducing the amount of material extruded during forming the second groove and facilitating smoothness of the predetermined pressure relief area.

[0012] In some embodiments, 0.4 mm ≤ L2 ≤ 1.2 mm. When L2 ≥ 0.4 mm, the first notch of the second groove has a sufficient width, which reduces the difficulty of forming the second groove and enhances the auxiliary turning effect of the second groove on the predetermined pressure relief area. When L2 ≤ 1.2 mm, the first notch of the second groove is not too wide, which reduces the amount of material extruded during the formation of the second groove and helps to improve the surface smoothness of the predetermined pressure relief area.

[0013] In some embodiments, the minimum residual thickness of the first groove is D1, and the minimum residual thickness of the second groove is D2, satisfying the following: D1 < D2. This ensures that the strength of the region where the first groove is located in the pressure relief component is less than the strength of the region where the second groove is located in the pressure relief component, so that the pressure relief component preferentially ruptures along the first groove, thereby achieving rapid opening of the predetermined pressure relief area.

[0014] In some embodiments, along the thickness direction of the first wall portion, the maximum groove depth of the first groove is H1, and the maximum groove depth of the second groove is H2, satisfying the following: H2 < H1. By setting the maximum groove depth of the first groove to be greater than the maximum depth of the second groove, the minimum residual thickness of the first groove is advantageously smaller than the minimum residual thickness of the second groove. During production, the depth of the first groove can be machined deeper than the depth of the second groove, thereby achieving a minimum residual thickness of the first groove smaller than the minimum residual thickness of the second groove.

[0015] In some embodiments, 0.3mm≤D2≤1.2mm. D2≥0.3mm ensures that the remaining portion of the second groove has sufficient strength. Furthermore, since D1<D2 and D2≥0.3mm, the remaining thickness of the first groove does not need to be machined too small, which helps reduce the difficulty of machining the first groove and improves the strength of the remaining portion of the first groove during normal use of the battery cell. D2≤1.2mm prevents the remaining thickness of the second groove from being too large, thereby improving the second groove's ability to assist in the flipping of the predetermined pressure relief area.

[0016] In some embodiments, the pressure relief component is provided with multiple second grooves, and the first groove defines multiple predetermined pressure relief areas, each of which corresponds to at least one second groove. In the event of thermal runaway of a battery cell, all of the predetermined pressure relief areas can be opened. Given a certain total pressure relief area of ​​the pressure relief component, the opening rate of the predetermined pressure relief areas can be increased, resulting in faster pressure relief.

[0017] In some embodiments, there are two predetermined pressure relief areas and two second grooves. The first groove includes a first groove section, which is located between the two second grooves along the width of the second groove. The two predetermined pressure relief areas are located on either side of the first groove section, with the side surface of the first groove closer to the first groove section than the side surface of the second groove. This allows the first groove section of the first groove to be located between the two predetermined pressure relief areas. After the pressure relief component is split along the first groove section, the two predetermined pressure relief areas can open in a split manner to relieve pressure when the battery cell releases pressure. This allows the two predetermined pressure relief areas to open quickly, which helps to increase the pressure relief rate of the battery cell.

[0018] In some embodiments, along the thickness direction of the first wall portion, the projection of the second groove does not overlap with the projection of the first groove, thereby reducing the mutual influence between the first groove and the second groove during the processing and lowering the risk of the first groove and the second groove communicating with each other during the processing.

[0019] In some embodiments, the second groove is spaced apart from the first groove along its width. This ensures that the projection of the second groove along the thickness of the first wall portion does not overlap with the projection of the first groove along the thickness of the first wall portion. This reduces the mutual influence between the first and second grooves during processing and reduces the residual stress between the region where the first groove is provided and the region where the second groove is provided. This reduces the risk of cracks in the pressure relief component along the first groove propagating to the second groove, thereby causing the pressure relief component to crack along the second groove.

[0020] In some embodiments, along the thickness direction of the first wall portion, two ends of the projection of the second groove in the extension direction respectively extend beyond two ends of the projection of the first groove, making the second groove longer and enhancing the auxiliary flipping effect of the second groove on the predetermined pressure relief area.

[0021] In some embodiments, the first groove is recessed from the second surface toward the first surface, so that the first groove and the second groove are located on opposite sides of the pressure relief component in the thickness direction, respectively. This facilitates machining the first groove and the second groove on opposite sides of the pressure relief component, thereby reducing mutual influence between the first groove and the second groove during machining.

[0022] In some embodiments, along the width direction of the second groove, the projections of the first groove and the second groove at least partially overlap. This allows the projections of the first groove and the second groove in the width direction of the second groove to have an overlapping area. This, on the one hand, can improve the second groove's ability to absorb excess material extruded from the first groove during molding, reducing the risk of the extruded material from the first groove diffusing to the surface of the housing along the width direction of the second groove, thereby causing surface unevenness. On the other hand, this can improve the second groove's ability to absorb deformation energy from the battery cell when the battery cell is subjected to internal and external forces and deformed along the width direction of the second groove, reducing the impact of the battery cell's expansion and deformation along the width direction of the second groove on the pressure relief component.

[0023] In some embodiments, along the thickness direction of the first wall portion, the bottom surface of the second groove is closer to the second surface than the bottom surface of the first groove. This structure facilitates achieving a greater overlap between the projections of the second groove and the first groove in the width direction of the second groove, further improving the second groove's ability to absorb excess material extruded from the first groove during molding, and further improving the second groove's ability to absorb deformation energy from the battery cell when the battery cell is deformed by internal and external forces along the width direction of the second groove.

[0024] In some embodiments, along the thickness direction of the first wall portion, the maximum groove depth of the second groove is H2, and the minimum residual thickness of the first groove is D1, satisfying the following relationship: D1 < H2. This structure facilitates achieving a greater overlap between the projections of the second groove and the first groove in the width direction of the second groove, further enhancing the second groove's ability to absorb excess material extruded from the first groove during molding. It also further enhances the second groove's ability to absorb deformation energy from the battery cell when the cell is deformed by internal and external forces along the width direction of the second groove.

[0025] In some embodiments, the first groove comprises a plurality of grooves arranged sequentially along a direction from the second surface to the first surface, wherein, along the thickness direction of the first wall portion, of two adjacent grooves, the first groove farther from the second surface is arranged at the bottom surface of the first groove closer to the second surface; wherein, among the plurality of grooves, the first groove arranged on the second surface is the first groove, and along the width direction of the second groove, the projections of the second groove and the first groove at least partially overlap. By arranging the first grooves as a plurality of grooves along the thickness direction of the first wall portion, each groove level can be machined one by one along the direction from the second surface to the first surface when forming the first groove, thereby reducing the forming depth of each groove level, reducing the forming force applied to the pressure relief component during the forming of the first groove, and reducing the risk of damage to the pressure relief component during the forming of the first groove. Since the projections of the first-level groove of the first groove and the second groove in the width direction of the second groove at least partially overlap, the projection of the second groove in the width direction can cover the grooves of all levels in the first groove except the first-level groove. On the one hand, this can improve the absorption effect of the second groove on the excess material squeezed out of the first groove when the multi-level groove is formed. On the other hand, it can further improve the absorption effect of the second groove on the deformation energy of the battery cell when the battery cell is subjected to internal and external impact forces and deformed, thereby reducing the influence of the expansion and deformation of the battery cell along the width direction of the second groove on the pressure relief component.

[0026] In some embodiments, along the thickness direction of the first wall portion, the bottom surface of the second groove is closer to the second surface than the bottom surface of the first groove. This allows the projection of the second groove in the width direction to cover a larger portion of the first groove. This, on the one hand, further improves the second groove's ability to absorb excess material extruded from the first groove during the multi-stage groove forming process. On the other hand, it further improves the second groove's ability to absorb deformation energy from the battery cell when it is deformed by internal and external impact forces, thereby reducing the impact of expansion and deformation of the battery cell along the width direction of the second groove on the pressure relief component.

[0027] In some embodiments, the first groove is recessed from the first surface toward the second surface. Thus, the first groove and the second groove are disposed on the same side of the pressure relief component in the thickness direction, making it easier to machine the first groove and the second groove on the pressure relief component. The first groove and the second groove can be machined without flipping the pressure relief component, which helps optimize the production cycle of battery cells.

[0028] In some embodiments, the first groove includes a plurality of grooves arranged in sequence along a direction pointing from the first surface to the second surface, and along the thickness direction of the first wall portion, in two adjacent grooves, the first groove farther away from the first surface is arranged at the groove bottom surface of the first groove closer to the first surface; wherein, among the multi-stage grooves, the first groove arranged on the first surface is the first-stage groove, and along the thickness direction of the first wall portion, the groove bottom surface of the first-stage groove is closer to the first surface than the groove bottom surface of the second groove. By arranging the first groove as a plurality of grooves along the thickness direction of the first wall portion, when forming the first groove, each stage of the groove can be processed one by one along the direction pointing from the first surface to the second surface, thereby reducing the forming depth of each stage of the groove, reducing the forming force applied to the pressure relief component when forming the first groove, and reducing the risk of the pressure relief component being damaged when forming the first groove. Since the bottom surface of the first-level groove is closer to the first surface than the bottom surface of the second groove, the projection of the second groove along the width direction at least covers the first-level groove of the first groove, so that the second groove has a deeper depth, so that the second groove can have a good absorption effect on the excess material squeezed out when forming the first-level groove, and the second groove can have a good absorption effect on the deformation energy of the battery cell when the battery cell is subjected to internal and external impact forces and deformed.

[0029] In some embodiments, along the thickness direction of the first wall portion, the maximum groove depth of the second groove is H2, and the maximum groove depth of the first groove is H3, satisfying the following: H3 < H2. This greater depth of the second groove effectively absorbs excess material extruded during the formation of the first groove and effectively absorbs deformation energy of the battery cell when the battery cell is deformed by internal and external impact forces.

[0030] In some embodiments, the first surface is the surface of the pressure relief component facing the interior of the housing. The second groove is arranged on the inner side of the pressure relief component. On the one hand, during the process of the predetermined pressure relief area being flipped outward and opened, the first groove side and the second groove side of the second groove are not likely to abut against each other, which is conducive to increasing the opening area of ​​the predetermined pressure relief area; on the other hand, the second groove is not exposed to the outside of the battery cell, reducing the risk of the pressure relief component being oxidized and corroded in the second groove area. In addition, when the first groove is arranged on the first surface, the first surface is the surface of the pressure relief component facing the interior of the housing, so that the first groove is arranged inside the pressure relief component, so that the first groove is not exposed to the outside of the battery cell, reducing the risk of the pressure relief component being oxidized and corroded in the first groove area.

[0031] In some embodiments, the first surface is the surface of the pressure relief component facing the outside of the shell. The second groove is arranged on the outside of the pressure relief component, which facilitates the processing and forming of the second groove on the outside of the battery cell, which is beneficial to reducing the difficulty of forming the second groove, thereby improving the production efficiency of the battery cell. Since the angle a between the side of the first groove and the first surface is smaller than the angle b between the side of the second groove and the first surface, the angle between the side of the first groove and the side of the second groove is increased, and the opening angle of the predetermined pressure relief area when the predetermined pressure relief area is flipped outward so that the side of the first groove and the side of the second groove are against each other is increased. In addition, in the case where the first groove is arranged on the first surface, the first surface is the surface of the pressure relief component facing the outside of the shell, so that the first groove is arranged on the outside of the pressure relief component, which facilitates the processing and forming of the first groove on the outside of the battery cell, thereby reducing the difficulty of forming the first groove, thereby improving the production efficiency of the battery cell.

[0032] In some embodiments, the first groove includes a first groove section and a second groove section, the first groove section and the second groove section being connected, and the first groove section and the second groove section together define at least one predetermined pressure relief area. This structure provides a simple first groove structure, and the stress at the connection between the first groove section and the second groove section is more concentrated, resulting in a weaker structure. This allows the pressure relief component to quickly separate from the first groove section and the second groove section after it ruptures at the connection between the first groove section and the second groove section during thermal runaway of the battery cell, allowing the predetermined pressure relief area to open more quickly and release pressure in a timely manner.

[0033] In some embodiments, the first groove includes a first groove section, a second groove section, and a third groove section. The second groove section and the third groove section are arranged opposite each other, and the first groove section connects the second groove section and the third groove section. Along the width direction of the second groove, the first groove section and the second groove section are spaced apart. The first groove section, the second groove section, and the third groove section jointly define at least one predetermined pressure relief area. The first groove with this structure makes the intersection of the first groove section and the second groove section and the connection between the first groove section and the third groove section weaker, making it easier to rupture and open the predetermined pressure relief area for pressure relief. It can also further increase the open area of ​​the predetermined pressure relief area, thereby increasing the pressure relief area of ​​the battery cell and improving the pressure relief rate of the battery cell.

[0034] In some embodiments, the connection position between the second groove section and the first groove section is offset from both ends of the second groove section, and the connection position between the third groove section and the first groove section is offset from both ends of the third groove section, so that predetermined pressure relief areas are formed on both sides of the first groove section. This allows the first groove section of the first groove to be located between the two predetermined pressure relief areas. After the pressure relief component is split along the first groove section, the two predetermined pressure relief areas can open in a split manner to relieve pressure when the battery cell is depressurized. This allows the two predetermined pressure relief areas to open quickly, which helps to increase the pressure relief rate of the battery cell.

[0035] In some embodiments, the first slot segment extends along a straight line or an arcuate trajectory; and / or the second slot segment extends along a straight line or an arcuate trajectory; and / or the third slot segment extends along a straight line or an arcuate trajectory. If the first slot segment extends along a straight line, the first slot segment is a straight slot, which can reduce the difficulty of forming the first slot segment. If the first slot segment extends along an arcuate trajectory, the first slot segment is an arcuate slot, and the pressure relief component is more likely to split along the first slot segment when the battery cell is depressurized, thereby achieving a faster opening of the predetermined pressure relief area. If the second slot segment extends along a straight line, the second slot segment is a straight slot, which can reduce the difficulty of forming the second slot segment. If the second slot segment extends along an arcuate trajectory, the second slot segment is an arcuate slot, and the pressure relief component is more likely to split along the second slot segment when the battery cell is depressurized, thereby achieving a faster opening of the predetermined pressure relief area. If the third slot segment extends along a straight line, the third slot segment is a straight slot, which can reduce the difficulty of forming the third slot segment. If the third groove section extends along an arc trajectory, the third groove section is an arc-shaped groove, and the pressure relief component is more likely to split along the third groove section when the battery cell releases pressure, thereby achieving faster opening of the predetermined pressure relief area.

[0036] In some embodiments, the first groove extends along an arc track. The first groove extends along an arc track, that is, the first groove is an arc groove. The first groove of this structure only includes one groove segment, which simplifies the structure of the first groove.

[0037] In some embodiments, the second groove extends along a straight line. The second groove is a straight groove with a simple structure and is easy to process and form.

[0038] In some embodiments, the pressure relief component is integrally formed with the first wall portion, so that the first groove and the second groove can be directly formed on the first wall portion, forming an integrated pressure relief structure, which has higher reliability, eliminates the installation process of the pressure relief component, and has better economy.

[0039] In some embodiments, the pressure relief component is separately provided with the first wall portion and is mounted on the first wall portion. The pressure relief component is a component independent of the housing, and the pressure relief component and the housing can be produced and assembled separately, which is easy to produce and efficient.

[0040] In some embodiments, the first groove is stamped and formed on the pressure relief component. In this way, the molding method of the first groove is simple, which is conducive to reducing the production cost of the battery cell.

[0041] In some embodiments, the second groove is stamped and formed on the pressure relief component. In this way, the second groove is formed in a simple manner, which is conducive to reducing the production cost of the battery cell.

[0042] In some embodiments, the first wall portion is a rectangular wall portion, and the first groove and the second groove are arranged along the width direction of the first wall portion. The second groove is closer to the edge of the first wall portion in the width direction of the first wall portion, so that the area where the second groove is set in the pressure relief component has higher strength, reducing the risk of the pressure relief component cracking along the second groove when the battery cell releases pressure. In addition, during normal use of the battery cell, the expansion of the battery cell in the width direction of the first wall portion is greater than the expansion in the length direction of the first wall portion, and the expansion of the battery cell in the width direction of the first wall portion has a greater impact on the pressure relief component. The first groove and the second groove are arranged along the width direction of the first wall portion, and the second groove can effectively absorb the deformation energy of the battery cell when the battery cell expands and deforms along the width direction of the first wall portion, thereby reducing the impact of the expansion of the battery cell along the width direction of the first wall portion on the pressure relief component.

[0043] In some embodiments, the housing includes a shell and an end cap; the shell has an opening formed at least at one end; the end cap corresponds to the opening and closes the opening; and at least one end cap is a first wall portion. This allows the at least one end cap to have a pressure relief function, making it easier to form the first and second grooves on the end cap or to install a pressure relief component.

[0044] In some embodiments, the housing includes a shell and an end cap; the shell has an opening formed at least at one end; the end cap corresponds to the opening and closes the opening; and at least one wall portion of the shell is a first wall portion. This allows the shell to have a pressure relief function. When the battery cell is depressurized, the exhaust from the battery cell is less likely to affect external components outside the end cap, thereby reducing the risk of damage to the external components by the exhaust.

[0045] In some embodiments, the housing has an opening at only one end, and the wall of the housing opposite the end cap is the first wall. This single-end opening simplifies the overall battery cell structure. The first wall, the wall of the housing opposite the end cap, allows for directional pressure relief from the bottom of the housing.

[0046] In some embodiments, the housing has openings at both opposing ends, and at least one wall portion of the housing is a first wall portion. The housing has openings at both opposing ends, and the electrode assembly can be assembled into the housing through either opening, which can reduce the difficulty of assembling the battery cells and improve the assembly quality of the battery cells. This housing structure can be made longer (the housing has openings at both ends in the longitudinal direction), which helps increase the capacity of the battery cells.

[0047] In some embodiments, the pressure relief component is made of steel. Steel has high strength, and the pressure relief component made of steel has better strength. Under a certain bursting pressure of the battery cell, the pressure relief component can be made thinner, reducing the volume of the pressure relief component.

[0048] In some embodiments, the steel material is carbon steel or stainless steel.

[0049] In some embodiments, the pressure relief component is made of aluminum alloy, which is lightweight and ductile, making it easier to machine the first groove and the second groove on the pressure relief component.

[0050] In some embodiments, the aluminum alloy includes the following composition by weight: aluminum ≥ 99.6%, copper ≤ 0.05%, iron ≤ 0.35%, magnesium ≤ 0.03%, manganese ≤ 0.03%, silicon ≤ 0.25%, titanium ≤ 0.03%, vanadium ≤ 0.05%, zinc ≤ 0.05%, and other individual elements ≤ 0.03%. This aluminum alloy has lower hardness and better formability, reduces the difficulty of machining the first and second grooves, improves the machining accuracy of the first and second grooves, and enhances the pressure relief consistency of the pressure relief component.

[0051] In some embodiments, the aluminum alloy includes the following composition by weight: aluminum ≥ 96.7%, copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other individual elements ≤ 0.05%, and other elements combined ≤ 0.15%. Pressure relief components made from this aluminum alloy have increased hardness, strength, and excellent damage resistance.

[0052] In a second aspect, an embodiment of the present application provides a battery, comprising a battery cell provided in any one embodiment of the first aspect.

[0053] In a third aspect, an embodiment of the present application provides an electrical device, comprising a battery cell provided in any one embodiment of the first aspect, wherein the battery cell is used to provide electrical energy to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] 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.

[0055] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0056] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0057] FIG3 is an exploded view of a battery cell provided in some embodiments of the present application;

[0058] FIG4 is an assembly diagram of the battery cell shown in FIG3 ;

[0059] FIG5 is a partial view of the housing shown in FIG4 ;

[0060] FIG6 is a cross-sectional view taken along line AA of the housing shown in FIG5 ;

[0061] FIG7 is a partial enlarged view of point B in FIG6;

[0062] FIG8 is a partial enlarged view of point C in FIG7;

[0063] FIG9 is an assembly diagram of battery cells provided in some other embodiments of the present application;

[0064] FIG10 is a partial view of the housing shown in FIG9;

[0065] FIG11 is a DD cross-sectional view of the housing shown in FIG10 ;

[0066] FIG12 is a partial enlarged view of point E in FIG11 ;

[0067] FIG13 is a partial cross-sectional view of a housing provided in some embodiments of the present application;

[0068] FIG14 is a partial enlarged view of point F in FIG13;

[0069] FIG15 is a partial view of a housing provided in some other embodiments of the present application;

[0070] FIG16 is a cross-sectional view taken along line GG of the housing shown in FIG15 ;

[0071] FIG17 is a partial view of a housing provided in some further embodiments of the present application;

[0072] FIG18 is a cross-sectional view taken along line HH of the housing shown in FIG17 ;

[0073] FIG19 is an exploded view of a housing (an opening is formed at one end of the housing, and the end cover is a pressure relief component) provided in some embodiments of the present application;

[0074] FIG20 is an exploded view of a housing (an opening is formed at one end of the housing, the end cover is a first wall portion, and a pressure relief component is installed on the first wall portion) provided in some embodiments of the present application;

[0075] FIG21 is an exploded view of a housing (an opening is formed at one end of the housing, the housing includes a first wall portion, and the pressure relief component is the first wall portion) provided in some embodiments of the present application;

[0076] FIG22 is an exploded view of a housing (an opening is formed at one end of the housing, the housing includes a first wall portion, and a pressure relief component is mounted on the first wall portion) provided in some embodiments of the present application;

[0077] FIG23 is an exploded view of a battery cell provided in some other embodiments of the present application.

[0078] Icons: 1-housing; 11-shell; 12-end cover; 13-first wall; 131-pressure relief hole; 14-second wall; 15-third wall; 2-electrode assembly; 21-electrode tab; 3-electrode terminal; 4-current collecting member; 5-insulating member; 6-pressure relief member; 61-first groove; 611-first groove section; 612-second groove section; 613-third groove section; 614-bottom surface of the first groove; 615-first-stage groove; 62-second groove; 621-side surface of the first groove; 622- Side surface of the second groove; 623-first end; 624-second end; 625-bottom surface of the first groove; 626-first notch; 63-predetermined pressure relief area; 64-first surface; 65-second surface; 10-battery cell; 20-housing; 201-first part; 202-second part; 100-battery; 200-controller; 300-motor; 1000-vehicle; W-first connecting line; X-thickness direction of the first wall; Y-extension direction of the second groove; Z-width direction of the second groove. DETAILED DESCRIPTION

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] The term "plurality" used in this application refers to two or more (including two).

[0086] 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.

[0087] Battery cells include but are not limited to lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0088] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process, active ions (such as lithium ions) move back and forth between the positive and negative electrodes. A separator, placed between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0089] 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.

[0090] 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.

[0091] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0092] 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 NCM622 ), 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.

[0093] 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.

[0094] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0095] As an example, the negative electrode current collector may be a metal foil, a metal foam, or a composite current collector. For example, the metal foil may be silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium. The metal foam may be nickel foam, copper foam, aluminum foam, or alloy foam. The composite current collector may include a polymer base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy, etc.) on a polymer substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] In some embodiments, the separator is a separator membrane, which can be any known porous separator membrane with good chemical and mechanical stability.

[0101] As an example, the separator can be made of at least one of fiberglass, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film. In the case of a multi-layer composite film, the materials of each layer can be the same or different. The separator can be a separate component positioned between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0102] 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.

[0103] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel, or solid. Liquid electrolytes include an electrolyte salt and a solvent.

[0104] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium bisoxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0105] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0106] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0107] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0108] 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.

[0109] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0110] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0111] 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.

[0112] In some embodiments, the electrode assembly is a laminate structure.

[0113] 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.

[0114] 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.

[0115] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0116] 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.

[0117] 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.

[0118] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0119] 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.

[0120] 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.

[0121] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. Prismatic battery cells include square-shell battery cells, blade-shaped battery cells, and polygonal prismatic batteries. Polygonal prismatic batteries are, for example, hexagonal prismatic batteries.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0127] 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.

[0128] In order to improve the reliability of battery cells, a pressure relief component can generally be provided in the battery cells. The pressure relief component can be a part of the battery cell shell or a component installed on the shell. When the battery cell thermally runs away, the pressure inside the battery cell can be released through the pressure relief component.

[0129] In order to achieve timely pressure relief of the battery cell, a pressure relief groove can be provided on the pressure relief component, and a predetermined pressure relief area is defined by the pressure relief groove so that the pressure relief component can be split along at least a portion of the pressure relief groove when the battery cell is relieved of pressure, so that the predetermined pressure relief area of ​​the pressure relief component can be quickly opened to release the pressure inside the battery cell more quickly.

[0130] In order to make the predetermined pressure relief area of ​​the pressure relief component easier to open, a flip groove can be provided on the pressure relief component. The flip groove can help the pressure relief area of ​​the pressure relief component to open, thereby reducing the difficulty of opening the pressure relief area. As for the flip notch, in the width direction of the flip groove, the flip groove has two opposite groove sides. The inclination angles of the two groove sides are the same and both are large. When forming the flip groove, the excess material squeezed out of the flip groove may diffuse to the predetermined pressure relief area, causing the extruded excess material to accumulate in the predetermined pressure relief area, forming a material bulge protruding from the surface of the predetermined pressure relief area, affecting the flatness of the surface of the predetermined pressure relief area, and causing the predetermined pressure relief area to open prematurely during normal use of the battery cell, affecting the service life of the battery cell. For example, if the flip groove is provided on the surface of the pressure relief component facing the interior of the shell, it may cause a material bulge to form on the inner surface of the predetermined pressure relief area, increasing the risk that the components inside the shell apply extrusion force to the material bulge, causing the predetermined pressure relief area to open prematurely. For example, if the flip groove is set on the surface of the pressure relief component facing the outside of the shell, it may cause a material pile protrusion to form on the outer surface of the predetermined pressure relief area, increasing the risk of the external component applying an extrusion force to the material pile protrusion, causing the predetermined pressure relief area to open prematurely.

[0131] Based on the above considerations, and to alleviate the problem of premature opening of a predetermined pressure relief zone affecting the service life of a battery cell, embodiments of the present application provide a battery cell comprising a housing and a pressure relief component. The housing comprises a first wall portion, and the pressure relief component is disposed on the first wall portion. The pressure relief component is provided with a first groove (pressure relief groove) and a second groove (flip groove). The first groove defines at least one predetermined pressure relief zone. The pressure relief component is configured to rupture along at least a portion of the first groove when the battery cell releases pressure. Along the thickness direction of the first wall portion, the pressure relief component has opposing first and second surfaces. The second groove is recessed from the first surface toward the second surface. The second groove is configured to guide the flipping of at least a portion of the predetermined pressure relief zone to open at least a portion of the predetermined pressure relief zone. Along the width direction of the second groove, the second groove comprises a first groove side surface and a second groove side surface disposed opposite and connected to the first surface. The first groove side surface is closer to the predetermined pressure relief zone than the second groove side surface. The first groove side surface forms an angle a with the first surface, and the second groove side surface forms an angle b with the first surface, satisfying the following: 90°≤a<b<180°.

[0132] In such a battery cell, the angle between the side surface of the first groove and the first surface is smaller than the angle between the side surface of the second groove and the first surface, which is equivalent to reducing the angle between the side surface of the first groove and the first surface. This can reduce the amount of excess material squeezed out when forming the second groove and diffusing to the predetermined pressure relief area, reduce the height of the pile bulge formed by the accumulation of excess material squeezed out from the area where the second groove of the pressure relief component is set in the predetermined pressure relief area, improve the flatness of the surface of the predetermined pressure relief area, reduce the risk of the predetermined pressure relief area opening prematurely due to poor surface flatness, and improve the service life of the battery cell.

[0133] The battery cells described in the embodiments of the present application are suitable for batteries and electrical equipment using the battery cells.

[0134] 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.

[0135] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] Please refer to Figure 2, which is an exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a battery cell 10 and a housing 20, wherein the battery cell 10 is accommodated in the housing 20.

[0140] The housing 20 is a component that houses the battery cells 10 and provides a storage space for the battery cells 10. The housing 20 can have various structures. In some embodiments, the housing 20 can include a first portion 201 and a second portion 202, which overlap to define a storage space for the battery cells 10. The first portion 201 and the second portion 202 can have various shapes, such as a rectangular parallelepiped or a cylindrical shape. The first portion 201 can be a hollow structure with one side open, and the second portion 202 can also be a hollow structure with one side open. The open side of the second portion 202 overlaps the open side of the first portion 201, thereby forming the housing 20 with a storage space. Alternatively, the first portion 201 can be a hollow structure with one side open, and the second portion 202 can be a plate-like structure. The second portion 202 overlaps the open side of the first portion 201, thereby forming the housing 20 with a storage space. The first portion 201 and the second portion 202 can be sealed by a sealing element, which can be a sealing ring, sealant, etc.

[0141] 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.

[0142] 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, wherein the electrode assembly 2 is accommodated in the housing 1.

[0143] In some embodiments, the housing 1 may include a shell 11 and an end cover 12 , wherein the shell 11 has an opening and the end cover 12 closes the opening of the shell 11 .

[0144] The housing 11 is a component for accommodating the electrode assembly 2. The housing 11 can be a hollow structure with an opening at one end, or a hollow structure with openings at opposite ends. The housing 11 can have various shapes, such as a cylinder or a rectangular parallelepiped. The housing 11 can be made of various materials, such as copper, iron, aluminum, steel, and aluminum alloys.

[0145] The end cap 12 is a component that closes the opening of the shell 11 to isolate the internal environment of the battery cell 10 from the external environment. The end cap 12 and the shell 11 together define a receiving space for accommodating the electrode assembly 2, electrolyte and other components. The end cap 12 can be connected to the shell 11 by welding or rolling to close the opening of the shell 11. The shape of the end cap 12 can be adapted to the shape of the shell 1. For example, the shell 11 is a rectangular parallelepiped structure, and the end cap 12 is a rectangular plate structure adapted to the shell 1. For another example, the shell 11 is a cylindrical structure, and the end cap 12 is a circular plate structure adapted to the shell 11. The material of the end cap 12 can also be a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, plastic, etc. The material of the end cap 12 and the shell 11 can be the same or different.

[0146] In an embodiment where the housing 11 is open at one end, one end cap 12 may be provided. In an embodiment where the housing 11 is open at two opposite ends, two end caps 12 may be provided, each of which closes the two openings of the housing 11, and the two end caps 12 and the housing 11 together define a receiving space.

[0147] In some embodiments, the battery cell 10 may further include an electrode terminal 3, which is disposed on the outer casing 1. The electrode terminal 3 is used to electrically connect to the tab 21 of the electrode assembly 2 to output electrical energy from the battery cell 10. The electrode terminal 3 may be disposed on the shell 11 of the outer casing 1 or on the end cap 12 of the outer casing 1. The electrode terminal 3 and the tab 21 may be directly connected, for example, by direct welding the electrode terminal 3 and the tab 21. The electrode terminal 3 and the tab 21 may also be indirectly connected, for example, by indirectly connecting the electrode terminal 3 and the tab 21 through a current collecting member 4. The current collecting member 4 may be a metal conductor, such as copper, iron, aluminum, steel, an aluminum alloy, or the like.

[0148] As an example, as shown in FIG3 , an opening is formed at one end of the housing 11. There is only one end cap 12 in the outer shell 1, and each end cap 12 closes the opening of the housing 11. Two electrode terminals 3 are provided on the end cap 12, which are respectively a positive electrode terminal and a negative electrode terminal. A positive electrode tab and a negative electrode tab are formed on the end of the electrode assembly 2 facing the end cap 12. The positive electrode terminal is connected to the positive electrode tab via a current collecting member 4, and the negative electrode terminal is connected to the negative electrode tab via another current collecting member 4.

[0149] 3 , the battery cell 10 may further include an insulating member 5 . The insulating member 5 is a component that separates the housing 11 from the electrode assembly 2 , thereby achieving insulation isolation between the housing 11 and the electrode assembly 2 . The insulating member 5 is made of an insulating material, including but not limited to plastic, rubber, and the like.

[0150] As an example, the insulating member 5 wraps around the outside of the electrode assembly 2 along the circumference of the opening of the housing 11. There can be one or more electrode assemblies 2 within the housing 1. If there is a single electrode assembly 2, the insulating member 5 wraps around it. If there are multiple electrode assemblies 2, one insulating member 5 can be provided for each electrode assembly 2, with each insulating member 5 wrapping around a single electrode assembly 2. Alternatively, multiple electrode assemblies 2 can be formed as a single integral component, with the insulating member 5 wrapping around the integral component.

[0151] Referring to Figures 4-7, Figure 4 is an assembly diagram of the battery cell 10 shown in Figure 3; Figure 5 is a partial view of the housing 1 shown in Figure 4; Figure 6 is a cross-sectional view taken along line AA of the housing 1 shown in Figure 5; and Figure 7 is a partial enlarged view of point B in Figure 6. An embodiment of the present application provides a battery cell 10 comprising a housing 1 and a pressure relief component 6. The housing 1 includes a first wall 13, and the pressure relief component 6 is disposed on the first wall 13. The pressure relief component 6 is provided with a first groove 61 and a second groove 62. The first groove 61 defines at least one predetermined pressure relief area 63. The pressure relief component 6 is configured to rupture along at least a portion of the first groove 61 when the battery cell 10 releases pressure. Along the thickness direction X of the first wall, the pressure relief component 6 has opposing first and second surfaces 64, 65. The second groove 62 is recessed from the first surface 64 toward the second surface 65. The second groove 62 is configured to guide at least a portion of the predetermined pressure relief area 63 to flip, thereby opening at least a portion of the predetermined pressure relief area 63. Along the width direction Z of the second groove, the second groove 62 includes a first groove side surface 621 and a second groove side surface 622 that are oppositely arranged and connected to the first surface 64. The first groove side surface 621 is closer to the predetermined pressure relief area 63 than the second groove side surface 622. The angle between the first groove side surface 621 and the first surface 64 is a, and the angle between the second groove side surface 622 and the first surface 64 is b, satisfying: 90°≤a<b<180°, and the width direction Z of the second groove is perpendicular to the thickness direction X of the first wall portion.

[0152] The outer shell 1 may include multiple walls, which together define a receiving space inside the outer shell 1 to accommodate the battery cells 10, electrolyte, and other components. The other components may be current collecting members 4, insulating members 5, and other components. Among the multiple walls of the outer shell 1, one wall may be the first wall 13, or multiple walls may be the first wall 13. Taking the outer shell 1 as an example, if there are six walls in the outer shell 1 in the shape of a rectangular parallelepiped, one, two, three, four, five, or six walls may be the first wall 13. In the outer shell 1, at least one end cap 12 may be the first wall 13, or at least one wall in the shell 11 may be the first wall 13.

[0153] The pressure relief component 6 is a component within the battery cell 10 that relieves pressure within the battery cell 10. The pressure relief component 6 is disposed on the first wall portion 13. The pressure relief component 6 and the first wall portion 13 may be integrally formed, or they may be separate components, with the pressure relief component 6 being mounted on the first wall portion 13. If the pressure relief component 6 is integrally formed with the first wall portion 13, such that the pressure relief component 6 forms at least a portion of the first wall portion 13, the entire first wall portion 13 may serve as the pressure relief component 6, or a portion of the first wall portion 13 may serve as the pressure relief component 6.

[0154] The first groove 61 is a pressure relief groove provided in the pressure relief component 6. When the pressure inside the battery cell 10 reaches the burst pressure of the pressure relief component 6, the pressure relief component 6 can rupture along at least a portion of the first groove 61 to open a predetermined pressure relief area 63. It is understood that when the pressure inside the battery cell 10 is released, the pressure relief component 6 can rupture along the entire first groove 61 or along a portion of the first groove 61 to release the pressure inside the battery cell 10. The first groove 61 can be formed in various ways, such as by stamping or milling. The first groove 61 can include at least one groove segment, and the cross-section of the groove segment can have various shapes, such as rectangular or trapezoidal, with the cross-section of the groove segment perpendicular to its extension direction. The first groove 61 can have various shapes, such as a groove extending along an arcuate trajectory. For example, the first groove 61 can include multiple groove segments, and the multiple groove segments can form a U-shape, H-shape, V-shape, Y-shape, X-shape, etc.

[0155] The second groove 62 is a rotation groove provided in the pressure relief component 6. When the pressure relief component 6 ruptures along at least a portion of the first groove 61, the second groove 62 guides the rotation of at least a portion of the predetermined pressure relief area 63. In other words, the second groove 62 facilitates the rotation of the predetermined pressure relief area 63, making it easier for the predetermined pressure relief area 63 to rotate toward the outside of the battery cell 10, thereby quickly opening the predetermined pressure relief area 63. The second groove 62 can guide the rotation of the predetermined pressure relief area 63 in its entirety or only in a portion. During the pressure relief process of the battery cell 10, the pressure relief component 6 can rupture along at least a portion of the first groove 61, and generally does not rupture along the second groove 62. The minimum thickness of the remaining portion of the pressure relief component 6 in the area where the first groove 61 is provided can be smaller than the minimum thickness of the remaining portion of the pressure relief component 6 in the area where the second groove 62 is provided, making the area where the first groove 61 is provided easier to rupture than the area where the second groove 62 is provided. The second groove 62 can be formed in various ways, such as by stamping, milling, etc. The second groove 62 can have various shapes, such as a groove extending along an arc trajectory, or a groove extending along a straight trajectory. The cross-sectional shape of the second groove 62 can be various shapes, such as a rectangle, a trapezoid, etc.

[0156] The second groove 62 not only facilitates the flipping of the predetermined pressure relief area 63 but also provides a buffering function. The second groove 62 absorbs any excess material extruded during the molding of the first groove 61, reducing the risk of the material from the first groove 61 spreading to the surface of the housing 1 along the width direction Z of the second groove, thereby improving the surface smoothness of the housing 1 along the width direction Z of the second groove. When the housing 1 of the battery cell 10 is subjected to internal and external impact forces and deforms along the width direction Z of the second groove, the second groove 62 can absorb the deformation energy of the housing 1, reducing the impact of the expansion and deformation of the battery cell 10 along the width direction Z of the second groove on the pressure relief component 6.

[0157] The second groove 62 and the first groove 61 may be directly connected, or they may not contact each other. The second groove 62 and the first groove 61 may be provided on the same surface of the pressure relief component 6 along the thickness direction X of the first wall portion, or they may be provided on two opposing surfaces of the pressure relief component 6 along the thickness direction X of the first wall portion. If the second groove 62 and the first groove 61 are directly connected, they may be provided on the same surface of the pressure relief component 6. If the second groove 62 and the first groove 61 do not contact each other, the projection of the second groove 62 and the projection of the first groove 61 along the thickness direction X of the first wall portion may partially overlap or may not overlap.

[0158] The predetermined pressure relief area 63 is the area defined by the first groove 61 of the pressure relief component 6. The predetermined pressure relief area 63 defined by the first groove 61 may be one or more. The predetermined pressure relief area 63 can be opened when the pressure relief component 6 is cracked along the first groove 61. The predetermined pressure relief area 63 and the second groove 62 may correspond one to one, that is, each predetermined pressure relief area 63 is provided in correspondence with one second groove 62. It is also possible that each predetermined pressure relief area 63 is provided in correspondence with multiple second grooves 62. The predetermined pressure relief area 63 may be in the shape of a triangle, a rectangle, a trapezoid, a semicircle, etc. In the embodiment shown in Figure 5, there are two predetermined pressure relief areas 63, and the two shaded parts shown in Figure 5 are the two predetermined pressure relief areas 63.

[0159] One of the first surface 64 and the second surface 65 can be the outer surface of the pressure relief component 6, and the other can be the inner surface of the pressure relief component 6. The outer surface of the pressure relief component 6 faces the outside of the battery cell 10, and the inner surface of the pressure relief component 6 faces the inside of the battery cell 10. The first surface 64 and the second surface 65 can be planes. The first surface 64 and the second surface 65 can be arranged in parallel or at a non-zero angle. The second groove 62 is recessed from the first surface 64 toward the direction close to the second surface 65, that is, the second groove 62 is arranged on the first surface 64. The first groove 61 can be arranged on the first surface 64 or on the second surface 65. As an example, in the embodiment shown in Figure 7, the first surface 64 is the inner surface of the pressure relief component 6, the second surface 65 is the outer surface of the pressure relief component 6, and the first groove 61 is arranged on the second surface 65.

[0160] The first groove side surface 621 can be a plane, an arc surface, etc. If the first groove side surface 621 is an arc surface, the angle between the line connecting the two ends of the first groove side surface 621 along the depth direction of the second groove 62 and the first surface 64 is the angle a between the first groove side surface 621 and the first surface 64. The second groove side surface 622 can be a plane or an arc surface. If the second groove side surface 622 is an arc surface, the angle between the line connecting the two ends of the second groove side surface 622 along the depth direction of the second groove 62 and the first surface 64 is the angle b between the second groove side surface 622 and the first surface 64. The first groove side surface 621 and the first surface 64 can be directly connected or indirectly connected, for example, the first groove side surface 621 and the first surface 64 are smoothly transitioned through an arc surface; the second groove side surface 622 and the first surface 64 can be directly connected or indirectly connected, for example, the second groove side surface 622 and the first surface 64 are smoothly transitioned through an arc surface. For example, in the embodiment shown in FIG. 7 , the first surface 64 , the first groove side 621 , and the second groove side 622 are all planar.

[0161] The first groove side surface 621 and the first surface 64 may be arranged at an obtuse angle or a right angle, and the second groove side surface 622 and the first surface 64 may be arranged at an obtuse angle. As an example, ba ≥ 3°.

[0162] When measuring angle a and angle b, the pressure relief component 6 can be cut along a direction perpendicular to the extension direction Y of the second groove, and then the angles between the first groove side surface 621 and the first surface 64, as well as the angles between the second groove side surface 622 and the first surface 64, can be measured on the cut surface using a measuring tool. Alternatively, a CT scanner can be used to scan and image the first groove side surface 621, the second groove side surface 622, and the first surface 64 on the cut surface, and then the angles between the first groove side surface 621 and the first surface 64, as well as the angles between the second groove side surface 622 and the first surface 64, can be measured.

[0163] As an example, in the embodiments shown in Figures 4-7 , the thickness direction X of the first wall is parallel to the first direction. The wall of the housing 11 opposite the end cap 12 serves as the pressure relief member 6. The first groove 61 and the second groove 62 are respectively provided on two opposing surfaces of the first wall in the thickness direction X. The first groove 61 is H-shaped, and the second groove 62 extends along a straight trajectory. The extension direction Y of the second groove is parallel to the second direction, and the width direction Z of the second groove is parallel to the third direction. The first, second, and third directions are perpendicular to each other. The first direction is the height direction of the battery cell 10, the second direction is the length direction of the battery cell 10, and the third direction is the thickness direction of the battery cell 10.

[0164] In the embodiment of the present application, the pressure relief component 6 is provided with a first groove 61, which defines at least one predetermined pressure relief area 63. This allows the pressure relief component 6 to split along at least a portion of the first groove 61 when the battery cell 10 releases pressure, thereby opening the predetermined pressure relief area 63 and releasing the internal pressure of the battery cell 10. The pressure relief component 6 is also provided with a second groove 62, which can guide at least a portion of the predetermined pressure relief area 63 to flip over, thereby opening at least a portion of the predetermined pressure relief area 63 for pressure relief. The second groove 62 assists the predetermined pressure relief area 63, making it easier to flip over the predetermined pressure relief area 63, reducing the difficulty of flipping the predetermined pressure relief area 63, and allowing the predetermined pressure relief area 63 to open more quickly during the process of the pressure relief component 6 splitting along the first groove 61, thereby increasing the opening rate of the predetermined pressure relief area 63. In addition, since a<b, it is equivalent to reducing the angle between the first groove side 621 and the first surface 64, which can reduce the amount of excess material squeezed out when forming the second groove 62 and diffused to the predetermined pressure relief area 63, and reduce the height of the pile bulge formed by the accumulation of excess material squeezed out from the area where the second groove 62 is set in the pressure relief component 6 in the predetermined pressure relief area 63, thereby improving the flatness of the surface of the predetermined pressure relief area 63, reducing the risk of the predetermined pressure relief area 63 opening prematurely due to poor surface flatness, and improving the service life of the battery cell 10.

[0165] In some embodiments, 90°≤a≤150°.

[0166] In this embodiment, a can take any point value among 90°, 100°, 110°, 120°, 130°, 135°, 140°, 150°, etc., or a range value between any two of them.

[0167] In this embodiment, 90°≤a≤150°, which reduces the influence of the first groove side surface 621 on the molding tool, makes it easier to remove the molding tool from the second groove 62, and reduces the molding difficulty of the second groove 62.

[0168] In some embodiments, 90°<b≤170°.

[0169] In this embodiment, b can take any point value among 91°, 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, 150°, 155°, 160°, 165°, 170°, etc., or a range value between any two of them.

[0170] In this embodiment, 90°<b≤170°, which reduces the influence of the second groove side surface 622 on the molding tool, makes it easier to remove the molding tool from the second groove 62, and reduces the molding difficulty of the second groove 62.

[0171] In some embodiments, please continue to refer to FIG8 , which is a partial enlarged view of point C in FIG7 . The second groove 62 further includes a first groove bottom surface 625 , which connects the first groove side surface 621 and the second groove side surface 622 . The second groove 62 forms a first notch 626 on the first surface 64 . Along the width direction Z of the second groove, the width of the first groove bottom surface 625 is L1 , and the width of the first notch 626 is L2 , satisfying the following: L1 < L2 .

[0172] The first groove bottom surface 625 can be a plane or an arc surface. If the first groove bottom surface 625 is a plane, the connection between the first groove bottom surface 625 and the first groove side surface 621 can form a rounded corner, and the connection between the first groove bottom surface 625 and the second groove side surface 622 can form a rounded corner.

[0173] As an example, the width of the second groove 62 gradually decreases from the first groove opening 626 to the direction of the first groove bottom surface 625. The groove bottom surface of the second groove 62 (the first groove bottom surface 625) is a plane parallel to the first surface 64. The angle between the groove bottom surface of the second groove 62 and the first groove side surface 621 is equal to the angle a between the first groove side surface 621 and the first surface 64. The angle between the groove bottom surface of the second groove 62 and the second groove side surface 622 is equal to the angle b between the second groove side surface 622 and the first surface 64.

[0174] In this embodiment, L1<L2, so that the second groove 62 has a structure with a wide top and a narrow bottom, which facilitates the removal of a molding tool used to mold the second groove 62 from the second groove 62 and facilitates the molding of the second groove 62.

[0175] In some embodiments, 0.05 mm ≤ L1 ≤ 0.3 mm;

[0176] L1 can be any point value among 0.05mm, 0.08mm, 0.1mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, etc., or a range value between any two of them.

[0177] In this embodiment, L1 is ≥ 0.05 mm, ensuring that the bottom surface of the second groove 62 has sufficient width. This reduces the difficulty of forming the second groove 62 and reduces the risk of stress concentration and insufficient strength of the remaining portion of the second groove 62 due to an excessively narrow bottom surface width. When L1 is ≤ 0.3 mm, the bottom surface of the second groove 62 is not too wide, reducing the amount of material extruded during forming the second groove 62 and facilitating the smoothness of the predetermined pressure relief area 63.

[0178] In some embodiments, 0.4 mm ≤ L2 ≤ 1.2 mm.

[0179] L2 can take any point value among 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, etc., or a range value between any two of them.

[0180] In this embodiment, L2≥0.4mm, so that the first notch 626 of the second groove 62 has a sufficient width, reducing the difficulty of forming the second groove 62 and enhancing the auxiliary flipping effect of the second groove 62 on the predetermined pressure relief area 63; L2≤1.2mm, so that the first notch 626 of the second groove 62 is not too wide, reducing the amount of extrusion when forming the second groove 62, which is beneficial to improving the flatness of the surface of the predetermined pressure relief area 63.

[0181] In some embodiments, referring to FIG. 7 and FIG. 8 , the minimum residual thickness of the first groove 61 is D1 , and the minimum residual thickness of the second groove 62 is D2 , satisfying: D1 < D2 .

[0182] The minimum residual thickness of the first groove 61 is the minimum thickness of the remaining portion after the pressure relief component 6 is provided with the first groove 61, and the remaining portion may be the bottom wall of the first groove 61. The thickness of the bottom wall of the first groove 61 may be uniform or uneven. If the thickness of the bottom wall of the first groove 61 is uneven, the thickness of the thinnest position of the bottom wall of the first groove 61 is the minimum residual thickness of the first groove 61. In an embodiment where the first groove 61 includes multiple groove segments, the minimum residual thicknesses of all groove segments may be equal, and the minimum residual thickness of any groove segment is the minimum residual thickness of the first groove 61; if the minimum residual thicknesses of at least two groove segments are unequal, the minimum residual thickness of the groove segment with the smallest minimum residual thickness is the minimum residual thickness of the first groove 61. The minimum residual thickness of a groove segment is the minimum thickness of the remaining portion after the pressure relief component 6 is provided with the groove segment, and the remaining portion may be the bottom wall of the groove segment.

[0183] The minimum residual thickness of the second groove 62 is the minimum thickness of the remaining portion of the pressure relief component 6 after the second groove 62 is provided. The remaining portion may be the bottom wall of the second groove 62. The thickness of the bottom wall of the second groove 62 may be uniform or uneven. If the thickness of the bottom wall of the second groove 62 is uneven, the thickness of the thinnest portion of the bottom wall of the second groove 62 is the minimum residual thickness of the second groove 62.

[0184] In this embodiment, D1<D2, so that the strength of the area where the first groove 61 of the pressure relief component 6 is set is less than the strength of the area where the second groove 62 of the pressure relief component 6 is set, so that the pressure relief component 6 can preferentially break along the first groove 61 to achieve rapid opening of the predetermined pressure relief area 63.

[0185] In some embodiments, along the thickness direction of the first wall portion 13 , the maximum groove depth of the first groove 61 is H1 , and the maximum groove depth of the second groove 62 is H2 , satisfying: H2 < H1 .

[0186] The maximum distance between the notch of the first groove 61 and the groove bottom surface 614 of the first groove along the thickness direction X of the first wall portion is the maximum groove depth of the first groove 61; the maximum distance between the notch of the second groove 62 (first notch 626) and the groove bottom surface (first groove bottom surface 625) of the second groove 62 along the thickness direction X of the first wall portion is the maximum groove depth of the second groove 62.

[0187] As an example, the first surface 64 is parallel to the second surface 65 , the distance between the first surface 64 and the second surface 65 is D, the thickness of the pressure relief component 6 is D, and D= D1 + H1 = D2 + H2 .

[0188] In this embodiment, H2

[0189] In some embodiments, along the thickness direction X of the first wall portion, the maximum groove depth of the first groove 61 is H1, the thickness of the pressure relief component 6 is D, and 0.16≤H1 / D<1.

[0190] H1 / D can take any point value among 0.16, 0.18, 0.2, 0.22, 0.25, 0.28, 0.3, 0.32, 0.35, 0.38, 0.4, 0.42, 0.45, 0.48, 0.5, 0.62, 0.65, 0.68, 0.7, 0.72, 0.75, 0.78, 0.8, 0.82, 0.85, 0.88, 0.9, 0.92, 0.95, 0.98, 0.99, etc., or a range of values ​​between any two of them.

[0191] ​It is understandable that if the pressure relief component 6 and the first wall portion 13 are integrally formed, the first wall portion 13 can serve as the pressure relief component 6 , and the thickness of the pressure relief component 6 is the same as the thickness of the first wall portion 13 .

[0192] In this embodiment, 0.16≤H1 / D<1, so that the maximum depth of the first groove 61 accounts for a small proportion of the thickness of the pressure relief component 6, and the bursting pressure of the battery cell 10 is not too high, which is conducive to improving the timeliness of the pressure relief of the battery cell 10.

[0193] In some embodiments, 0.4 mm ≤ H1 ≤ 2 mm, and 0.8 mm ≤ D ≤ 2.5 mm.

[0194] H1 can be any point value among 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.05mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.45mm, 1.5mm, 1.55mm, 1.6mm, 1.65mm, 1.7mm, 1.75mm, 1.8mm, 1.85mm, 1.9mm, 1.95mm, 2mm, etc., or a range value between any two of them.

[0195] D can be any point value among 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.05mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.45mm, 1.5mm, 1.55mm, 1.6mm, 1.65mm, 1.7mm, 1.75mm, 1.8mm, 1.85mm, 1.9mm, 1.95mm, 2mm, 2.05mm, 2.1mm, 2.15mm, 2.2mm, 2.25mm, 2.3mm, 2.35mm, 2.4mm, 2.45mm, 2.5mm, etc., or a range value between any two of them.

[0196] In some embodiments, 0.3 mm ≤ D2 ≤ 1.2 mm.

[0197] L2 can take any point value among 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, etc., or a range value between any two of them.

[0198] In this embodiment, D2 ≥ 0.3 mm ensures sufficient strength of the remaining portion of the second groove 62. Furthermore, since D1 < D2 and D2 ≥ 0.3 mm, the remaining thickness of the first groove 61 does not need to be machined too small, which reduces the difficulty of machining the first groove 61 and improves the strength of the remaining portion of the first groove 61 during normal use of the battery cell 10. D2 ≤ 1.2 mm prevents the remaining thickness of the second groove 62 from being excessively large, thereby enhancing the second groove 62's ability to assist in the flipping of the predetermined pressure relief area 63.

[0199] In some embodiments, referring to FIG. 5 , the pressure relief component 6 is provided with a plurality of second grooves 62 , the first groove 61 defines a plurality of predetermined pressure relief areas 63 , and each predetermined pressure relief area 63 is provided corresponding to at least one second groove 62 .

[0200] There may be two, three, four, or more second grooves 62, and there may be two, three, four, or more predetermined pressure relief areas 63 defined by the first groove 61. Each predetermined pressure relief area 63 may be provided corresponding to at least one second groove 62, that is, each predetermined pressure relief area 63 may be provided corresponding to one second groove 62, or may be provided corresponding to multiple second grooves 62.

[0201] In this embodiment, the first groove 61 defines a plurality of predetermined pressure relief areas 63. When the battery cell 10 thermally runs away, the plurality of predetermined pressure relief areas 63 can be opened. When the total pressure relief area of ​​the pressure relief component 6 is constant, the opening rate of the predetermined pressure relief areas 63 can be increased, and pressure relief can be achieved more quickly.

[0202] In some embodiments, there are two predetermined pressure relief areas 63 and two second grooves 62. The first groove 61 includes a first groove section 611. Along the width direction Z of the second groove, the first groove section 611 is located between the two second grooves 62. The two predetermined pressure relief areas 63 are located on either side of the first groove section 611, and the first groove side surface 621 is closer to the first groove section 611 than the second groove side surface 622.

[0203] It can be understood that the predetermined pressure relief area 63 corresponds to the second groove 62 on a one-to-one basis.

[0204] The first groove 61 may include a plurality of groove sections, and the first groove section 611 may be one of the plurality of groove sections. The first groove section 611 is a groove section in the first groove 61 that separates two predetermined pressure relief areas 63 .

[0205] The areas of the two predetermined pressure relief zones 63 may be equal or different. The first groove section 611 and the second groove 62 are arranged along the width direction Z of the second groove. The second groove 62 may be parallel to the first groove section 611, or the extension line of the second groove 62 may intersect the extension line of the first groove section 611.

[0206] As an example, in the embodiment shown in Figure 5, the multiple groove segments of the first groove 61 form an H-shaped structure, the first groove segment 611 and the second groove 62 both extend along a straight line, the first groove segment 611 is parallel to the second groove 62, the two second grooves 62 are equidistant from the first groove segment 611, and the two predetermined pressure relief areas 63 are symmetrically arranged on both sides of the first groove segment 611, so that the areas of the two predetermined pressure relief areas 63 are equal.

[0207] In this embodiment, there are two predetermined pressure relief areas 63 and two second grooves 62, and the first groove section 611 of the first groove 61 is located between the two second grooves 62, so that the first groove section 611 of the first groove 61 is located between the two predetermined pressure relief areas 63. After the pressure relief component 6 is split along the first groove section 611, the two predetermined pressure relief areas 63 can be opened in a split manner to relieve pressure when the battery cell 10 is depressurized, so that the two predetermined pressure relief areas 63 can be opened quickly, which is beneficial to improving the pressure relief rate of the battery cell 10.

[0208] In some embodiments, referring to FIG. 5 , along the thickness direction X of the first wall portion, the projection of the second groove 62 does not overlap with the projection of the first groove 61 .

[0209] It can be understood that, along the thickness direction X of the first wall portion, the projection of the second groove 62 has no overlapping portion with the projection of the first groove 61 .

[0210] Along the thickness direction X of the first wall portion, the projection of the extension line of the second groove 62 may be connected to the projection of the first groove 61, or the projection of the extension line of the first groove 61 may be connected to the projection of the second groove 62, or the projection of the extension line of the first groove 61 may be connected to the projection of the extension line of the second groove 62.

[0211] The second groove 62 and the first groove 61 can be arranged on the same side of the pressure relief component 6 in the thickness direction X of the first wall portion, for example, the second groove 62 and the first groove 61 are both arranged on the first surface 64; the second groove 62 and the first groove 61 can also be arranged on different sides of the pressure relief component 6 in the thickness direction X of the first wall portion, for example, the first groove 61 is arranged on the second surface 65, and the second groove 62 is arranged on the first surface 64.

[0212] In this embodiment, the projection of the second groove 62 along the thickness direction X of the first wall portion does not overlap with the projection of the first groove 61 along the thickness direction X of the first wall portion, which can reduce the mutual influence between the first groove 61 and the second groove 62 during the processing process and reduce the risk of the first groove 61 and the second groove 62 being connected to each other during the processing.

[0213] In some embodiments, along the width direction Z of the second groove, the second groove 62 is spaced apart from the first groove 61 .

[0214] The second groove 62 is spaced apart from the first groove 61 along the width direction Z of the second groove. That is, the projection of the second groove 62 along the thickness direction X of the first wall portion is spaced apart from the projection of the first groove 61 along the thickness direction X of the first wall portion by a certain distance in the width direction Z of the second groove. In this embodiment, the second groove 62 and the first groove 61 can be located on the same side of the pressure relief component 6 in the thickness direction X of the first wall portion, or can be located on opposite sides of the pressure relief component 6 in the thickness direction X of the first wall portion. It will be understood that the projection of the second groove 62 along the thickness direction X of the first wall portion is spaced apart from the projection of the first groove 61 along the thickness direction X of the first wall portion along the width direction Z of the second groove.

[0215] As an example, in the embodiment shown in FIG6 , the housing 1 further includes a second wall portion 14 and a third wall portion 15 . Along the width direction Z of the second groove, the second wall portion 14 and the third wall portion 15 are disposed opposite each other. The first wall portion 13 connects the first wall portion 13 and the third wall portion 15 . The first wall portion 13 serves as the pressure relief component 6 . The first wall portion 13 is provided with two second grooves 62 . Along the width direction Z of the second groove, one second groove 62 is located between the first groove 61 and the second wall portion 14 , and the other second groove 62 is located between the first groove 61 and the third wall portion 15 .

[0216] In this embodiment, the second groove 62 and the first groove 61 are spaced apart along the width direction Z of the second groove, so that the projection of the second groove 62 along the thickness direction X of the first wall portion and the projection of the first groove 61 along the thickness direction X of the first wall portion do not overlap. On the one hand, the mutual influence between the first groove 61 and the second groove 62 during the processing can be reduced. On the other hand, the residual stress between the area where the first groove 61 of the pressure relief component 6 is set and the area where the second groove 62 of the pressure relief component 6 is set can be reduced, and the risk of cracks generated by the cracking of the pressure relief component 6 along the first groove 61 spreading to the second groove 62, thereby causing the pressure relief component 6 to crack along the second groove 62, can be reduced.

[0217] In the above embodiment, the second groove 62 is spaced apart from the first groove 61 along the width direction Z of the second groove, such that the projection of the first groove 61 along the thickness direction X of the first wall portion does not lie within the predetermined pressure relief zone 63. In other embodiments, the projection of the first groove 61 along the thickness direction X of the first wall portion may partially or entirely lie within the predetermined pressure relief zone 63.

[0218] In some embodiments, referring to FIG. 5 , along the thickness direction X of the first wall portion, two ends of the projection of the second groove 62 along the extension direction respectively extend beyond two ends of the projection of the first groove 61 .

[0219] Along the thickness direction X of the first wall portion, the projection of the second groove 62 has two opposite ends in the extension direction, namely, a first end 623 and a second end 624. The two ends of the projection of the second groove 62 along the extension direction extend beyond the two ends of the projection of the first groove 61, that is, the two ends of the projection of the first groove 61 are located between the first end 623 and the second end 624 along the extension direction of the projection of the second groove 62. The extension direction of the projection of the second groove 62 along the thickness direction X of the first wall portion is parallel to the second groove extension direction Y. As an example, along the second groove extension direction Y, the length of the second groove 62 is greater than the length of the first groove 61 (the maximum span of the first groove 61 along the second groove extension direction Y).

[0220] In this embodiment, along the thickness direction X of the first wall portion, the projection of the second groove 62 extends beyond the projection of the first groove 61 at both ends along the extension direction, making the second groove 62 longer and enhancing the second groove 62's assistive flipping effect on the predetermined pressure relief area 63. Furthermore, this structure can enhance the second groove 62's ability to separate the surface of the battery cell 10 in the width direction Z of the second groove (the outer surface of the second wall portion 14 or the outer surface of the third wall portion 15) from the first groove 61, improve the second groove 62's ability to absorb excess material extruded during the molding of the first groove 61, and improve the flatness of the surface of the battery cell 10 in the width direction Z of the second groove. Furthermore, it can enhance the second groove 62's ability to block deformation energy of the battery cell 10 when subjected to internal or external impact forces, thereby reducing the impact of battery cell 10 expansion on the pressure relief component 6.

[0221] In other embodiments, along the thickness direction X of the first wall portion, the projection of the second groove 62 may be located between two ends of the projection of the first groove 61 .

[0222] In some embodiments, referring again to FIG. 7 , the first groove 61 is recessed from the second surface 65 toward the first surface 64 .

[0223] It can be understood that the first groove 61 is provided on the second surface 65 , and the second groove 62 is provided on the first surface 64 .

[0224] As an example, the first surface 64 is parallel to the second surface 65, the minimum distance between the groove bottom surface 614 of the first groove and the first surface 64 along the thickness direction X of the first wall portion is equal to the minimum residual thickness of the first groove 61, and the minimum distance between the groove bottom surface (first groove bottom surface 625) of the second groove 62 and the second surface 65 along the thickness direction X of the first wall portion is equal to the minimum residual thickness of the second groove 62. The maximum groove depth of the first groove 61 is equal to the maximum distance between the second surface 65 and the groove bottom surface 614 of the first groove along the thickness direction X of the first wall portion, and the maximum groove depth of the second groove 62 is equal to the maximum distance between the first surface 64 and the groove bottom surface of the second groove 62 along the thickness direction X of the first wall portion.

[0225] In this embodiment, the first groove 61 is recessed from the second surface 65 toward the direction close to the first surface 64, so that the first groove 61 and the second groove 62 are respectively located on both sides of the pressure relief component 6 in the thickness direction X of the first wall portion, so that the first groove 61 and the second groove 62 can be processed on both sides of the pressure relief component 6, which is beneficial to reducing the mutual influence between the first groove 61 and the second groove 62 during the processing.

[0226] In some embodiments, referring to FIG. 7 , along the width direction Z of the second groove, the projections of the first groove 61 and the second groove 62 at least partially overlap.

[0227] The projection of the first groove 61 along the width direction Z of the second groove and the projection of the second groove 62 along the width direction Z of the second groove may partially overlap or completely overlap. If the two completely overlap, a first protrusion may be provided at a position on the second surface 65 corresponding to the second groove 62, so that the second groove 62 does not penetrate the pressure relief component 6 along the thickness direction X of the first wall. A second protrusion may be provided at a position on the first surface 64 opposite the first groove 61, so that the first groove 61 does not penetrate the pressure relief component 6 along the thickness direction X of the first wall.

[0228] It can be understood that the projections of the first groove 61 and the second groove 62 along the width direction Z of the second groove have an overlapping area. It can also be understood that the projections of the groove wall surface (groove bottom surface and groove side surface) of the first groove 61 and the groove wall surface (groove bottom surface and groove side surface) of the second groove 62 along the width direction Z of the second groove at least partially overlap.

[0229] It should be noted that if the groove bottom surface 614 of the first groove and the groove bottom surface of the second groove 62 (the first groove bottom surface 625) are exactly flush, the groove bottom surface 614 of the first groove and the groove bottom surface of the second groove 62 (the first groove bottom surface 625) overlap along the width direction Z of the second groove, and the overlapping area is a line. In this case, the projections of the first groove 61 and the second groove 62 also overlap.

[0230] In this embodiment, the projections of the first groove 61 and the second groove 62 at least partially overlap, so that the projections of the first groove 61 and the second groove 62 in the width direction Z of the second groove have overlapping areas. This can, on the one hand, improve the absorption effect of the second groove 62 on the residual material squeezed out during molding of the first groove 61, and reduce the risk of the extruded residual material of the first groove 61 diffusing to the surface close to the shell 1 along the width direction Z of the second groove, thereby causing the surface to be uneven. On the other hand, it can improve the absorption effect of the second groove 62 on the deformation energy of the battery cell 10 when the battery cell 10 is subjected to internal and external forces and deformed along the width direction Z of the second groove, and reduce the influence of the expansion and deformation of the battery cell 10 along the width direction Z of the second groove on the pressure relief component 6.

[0231] In some embodiments, along the thickness direction X of the first wall portion, the groove bottom surface of the second groove 62 (the first groove bottom surface 625 ) is closer to the second surface 65 than the groove bottom surface 614 of the first groove.

[0232] It can be understood that, along the thickness direction X of the first wall portion, the groove bottom surface of the second groove 62 (the first groove bottom surface 625 ) is located between the groove bottom surface 614 of the first groove and the second surface 65 .

[0233] In this embodiment, the groove bottom surface of the second groove 62 (the first groove bottom surface 625) is closer to the first surface 64 than the groove bottom surface 614 of the first groove. This structure is conducive to achieving more overlapping areas between the projections of the second groove 62 and the first groove 61 in the width direction Z of the second groove, further improving the absorption effect of the second groove 62 on the residual material squeezed out of the first groove 61 during molding, and further improving the absorption effect of the second groove 62 on the deformation energy of the battery cell 10 when the battery cell 10 is subjected to internal and external forces and deformed along the width direction Z of the second groove.

[0234] In some embodiments, along the thickness direction X of the first wall portion, the maximum groove depth of the second groove 62 is H2, and the minimum residual thickness of the first groove 61 is D1, satisfying: D1<H2.

[0235] As an example, the first surface 64 is parallel to the second surface 65, and the notch (first notch 626) of the second groove 62 is located on the first surface 64. The maximum distance between the notch (first notch 626) of the second groove 62 and the groove bottom surface (first groove bottom surface 625) of the second groove 62 along the thickness direction X of the first wall portion is the maximum groove depth of the second groove 62. Along the thickness direction X of the first wall portion, the portion between the groove bottom surface 614 of the first groove and the first surface 64 is the residual portion of the first groove 61, and the minimum thickness of this residual portion is the minimum residual thickness of the first groove 61. The first surface 64 serves as the reference surface for measuring the maximum groove depth of the second groove 62 and the minimum residual thickness of the first groove 61.

[0236] In this embodiment, D1<H2. This structure is conducive to achieving a larger overlapping area between the projections of the second groove 62 and the first groove 61 in the width direction Z of the second groove, further improving the absorption effect of the second groove 62 on the residual material squeezed out of the first groove 61 during molding, and further improving the absorption effect of the second groove 62 on the deformation energy of the battery cell 10 when the battery cell 10 is subjected to internal and external forces and deformed along the width direction Z of the second groove.

[0237] In some embodiments, please refer to Figures 9-12. Figure 9 is an assembly diagram of a battery cell 10 provided in other embodiments of the present application; Figure 10 is a partial view of the housing 1 shown in Figure 9; Figure 11 is a cross-sectional view taken along line DD of the housing 1 shown in Figure 10; and Figure 12 is a partial enlarged view of point E in Figure 11. The first groove 61 comprises a plurality of grooves arranged sequentially along the direction from the second surface 65 to the first surface 64. Along the thickness direction X of the first wall portion, in two adjacent grooves, the primary groove farther from the second surface 65 is arranged at the bottom surface of the primary groove closer to the second surface 65. The primary groove of the multi-stage groove arranged on the second surface 65 is the first groove 615. Along the width direction Z of the second groove, the projections of the second groove 62 and the first groove 615 at least partially overlap.

[0238] The first groove 61 can be a two-stage groove, a three-stage groove, a four-stage groove, a five-stage groove, or the like. It is understood that the first groove 61 is a stepped groove. The groove width of each stage gradually decreases as the second surface 65 points toward the first surface 64. As shown in FIG12 , taking the first groove 61 as a two-stage groove as an example, the two stages are a first-stage groove 615 and a second-stage groove. During machining, the first-stage groove 615 with a larger width can be machined first on the second surface 65, and then the second-stage groove with a smaller width can be machined on the bottom surface of the first-stage groove 615.

[0239] The first-stage groove 615 is a first-stage groove disposed on the second surface 65 within the first groove 61. In embodiments where the first groove 61 includes multiple groove segments, it is understood that each groove segment is a multi-stage groove, and all first-stage groove segments disposed on the second surface 65 constitute the first-stage groove 615. Among the multi-stage grooves of the first groove 61, the groove bottom surface of the first-stage groove farthest from the second surface 65 is the groove bottom surface 614 of the first groove, the minimum residual thickness of the first-stage groove farthest from the second surface 65 is the minimum residual thickness of the first groove 61, and the maximum distance between the groove bottom surface of the first-stage groove farthest from the second surface 65 and the second surface 65 is equal to the maximum groove depth of the first groove 61.

[0240] The projection of the second groove 62 along the width direction Z of the second groove may partially overlap or completely overlap with the projection of the first-stage groove 615 along the width direction Z of the second groove. If the two completely overlap, a first protrusion may be provided at a position on the second surface 65 corresponding to the second groove 62, so that the second groove 62 does not penetrate the pressure relief component 6 along the thickness direction X of the first wall. A second protrusion may be provided at a position on the first surface 64 opposite the first-stage groove 615, so that the first groove 61 does not penetrate the pressure relief component 6 along the thickness direction X of the first wall.

[0241] It can be understood that the projections of the second groove 62 and the first-stage groove 615 along the width direction Z of the second groove have an overlapping area. It can also be understood that the projections of the groove wall surface (groove bottom surface and groove side surface) of the second groove 62 and the groove wall surface (groove bottom surface and groove side surface) of the first-stage groove 615 along the width direction Z of the second groove at least partially overlap.

[0242] In this embodiment, by configuring the first groove 61 as a multi-stage groove arranged along the thickness direction X of the first wall portion, each stage of grooves can be machined one by one in the direction from the second surface 65 to the first surface 64 during the formation of the first groove 61. This reduces the depth of each stage of grooves, reduces the forming force applied to the pressure relief component 6 during the formation of the first groove 61, and reduces the risk of damage to the pressure relief component 6 during the formation of the first groove 61. Because the projections of the first stage groove 615 of the first groove 61 and the second groove 62 in the width direction Z of the second groove at least partially overlap, the projection of the second groove 62 in the width direction Z of the second groove 61 can cover all stages of grooves in the first groove 61 except the first stage groove 615. This improves the ability of the second groove 62 to absorb excess material extruded from the first groove 61 during the multi-stage groove formation process. Furthermore, it further improves the ability of the second groove 62 to absorb deformation energy from the battery cell 10 when the battery cell 10 is subjected to internal or external impact forces and deforms, thereby reducing the impact of expansion and deformation of the battery cell 10 in the width direction Z of the second groove on the pressure relief component 6.

[0243] In some embodiments, along the thickness direction X of the first wall portion, the groove bottom surface (first groove bottom surface 625 ) of the second groove 62 is closer to the second surface 65 than the groove bottom surface of the first-stage groove 615 .

[0244] It can be understood that, along the thickness direction X of the first wall portion, the groove bottom surface of the second groove 62 (the first groove bottom surface 625 ) is located between the groove bottom surface of the first-stage groove 615 and the second surface 65 .

[0245] The bottom surface of the second groove 62 (first groove bottom surface 625) can be a flat surface or an arcuate surface; the bottom surface of the first-stage groove 615 can be a flat surface or an arcuate surface. As an example, in the embodiment shown in FIG12 , the bottom surface of the first-stage groove 615 and the bottom surface of the second groove 62 (first groove bottom surface 625) are both flat surfaces and parallel to the first surface 64 and the second surface 65.

[0246] In this embodiment, the groove bottom surface of the second groove 62 (the first groove bottom surface 625) is closer to the second surface 65 than the groove bottom surface of the first-level groove 615, and the projection of the second groove 62 in the width direction can cover more parts of the first-level groove 615, thereby, on the one hand, further improving the absorption effect of the second groove 62 on the residual material squeezed out of the first groove 61 during the processing of the multi-level groove. On the other hand, it can further improve the absorption effect of the second groove 62 on the deformation energy of the battery cell 10 when the battery cell 10 is subjected to internal and external impact forces and deformed, thereby reducing the influence of the expansion deformation of the battery cell 10 along the width direction Z of the second groove on the pressure relief component 6.

[0247] In some other embodiments, along the thickness direction X of the first wall portion, the groove bottom surface of the second groove 62 (the first groove bottom surface 625 ) is flush with the groove bottom surface of the first-stage groove 615 .

[0248] In some embodiments, please refer to Figures 13 and 14. Figure 13 is a partial cross-sectional view of the housing 1 provided in some embodiments of the present application; Figure 14 is a partial enlarged view of point F in Figure 13. The first groove 61 is recessed from the first surface 64 toward the second surface 65.

[0249] It can be understood that the first groove 61 and the second groove 62 are both provided on the first surface 64 .

[0250] In this embodiment, the first groove 61 and the second groove 62 are arranged on the same side of the pressure relief component 6 in the thickness direction X of the first wall portion, which makes it easier to process the first groove 61 and the second groove 62 on the pressure relief component 6. The first groove 61 and the second groove 62 can be processed without flipping the pressure relief component 6, which is beneficial to optimizing the production rhythm of the battery cell 10.

[0251] In some embodiments, referring again to FIG. 14 , the first groove 61 includes a plurality of grooves sequentially arranged along a direction from the first surface 64 to the second surface 65. Along the thickness direction X of the first wall portion, in two adjacent grooves, the primary groove farther from the first surface 64 is arranged at the groove bottom surface of the primary groove closer to the first surface 64. Among the plurality of grooves, the primary groove arranged on the first surface 64 is the first groove 615. Along the thickness direction X of the first wall portion, the groove bottom surface of the first groove 615 is closer to the first surface 64 than the groove bottom surface of the second groove 62.

[0252] The first-stage groove 615 is a first-stage groove disposed on the first surface 64 of the first groove 61. Among the multi-stage grooves of the first groove 61, the groove bottom surface of the first-stage groove farthest from the first surface 64 is the groove bottom surface 614 of the first groove. The minimum residual thickness of the first-stage groove farthest from the first surface 64 is the minimum residual thickness of the first groove 61. The maximum distance between the groove bottom surface of the first-stage groove farthest from the first surface 64 and the first surface 64 is equal to the maximum groove depth of the first groove 61. Along the thickness direction X of the first wall portion, the minimum distance between the groove bottom surface of the second groove 62 (first groove bottom surface 625) and the second surface 65 is equal to the minimum residual thickness of the second groove 62. The minimum distance between the groove bottom surface of the first-stage groove farthest from the first surface 64 and the second surface 65 is equal to the minimum residual thickness of the first groove 61.

[0253] It can be understood that, along the thickness direction X of the first wall portion, the groove bottom surface of the first-stage groove 615 is located between the groove bottom surface of the second groove 62 (the first groove bottom surface 625 ) and the first surface 64 .

[0254] The bottom surface of the second groove 62 can be a flat surface or an arcuate surface; the bottom surface of the first-stage groove 615 can be a flat surface or an arcuate surface. As an example, in the embodiment shown in FIG14 , the bottom surface of the first-stage groove 615 and the bottom surface of the second groove 62 are both flat surfaces and parallel to the first surface 64 and the second surface 65.

[0255] In this embodiment, by configuring the first groove 61 as a multi-stage groove arranged along the thickness direction X of the first wall portion, each stage of grooves can be machined one by one in the direction from the first surface 64 to the second surface 65 during the formation of the first groove 61. This reduces the forming depth of each stage of grooves, reduces the forming force applied to the pressure relief component 6 during the formation of the first groove 61, and reduces the risk of damage to the pressure relief component 6 during the formation of the first groove 61. Because the bottom surface of the first stage groove 615 is closer to the first surface 64 than the bottom surface of the second groove 62, the projection of the second groove 62 along the width direction at least covers the first stage groove 615 of the first groove 61, resulting in a deeper depth of the second groove 62. This allows the second groove 62 to effectively absorb excess material extruded during the formation of the first stage groove 615. Furthermore, the second groove 62 effectively absorbs deformation energy of the battery cell 10 when the battery cell 10 is subjected to internal and external impact forces and deforms.

[0256] In some embodiments, referring to FIG. 14 , along the thickness direction X of the first wall portion, the maximum groove depth of the second groove 62 is H2, and the maximum groove depth of the first-level groove 615 is H3, satisfying: H3<H2.

[0257] As an example, the maximum distance between the groove bottom surface of the second groove 62 (the first groove bottom surface 625) and the first surface 64 along the thickness direction X of the first wall portion is the maximum groove depth of the second groove 62, and the maximum distance between the groove bottom surface of the first-stage groove 615 and the first surface 64 along the thickness direction X of the first wall portion is the maximum groove depth of the first-stage groove 615. The maximum groove depth of the second groove 62 is greater than the maximum groove depth of the first-stage groove 615, so that the groove bottom surface of the first-stage groove 615 is closer to the first surface 64 than the groove bottom surface of the second groove 62 (the first groove bottom surface 625).

[0258] In this embodiment, H3 is less than H2, so that the second groove 62 has a deeper depth, so that the second groove 62 can effectively absorb the excess material squeezed out when the first-level groove 615 is formed, and the second groove 62 can effectively absorb the deformation energy of the battery cell 10 when the battery cell 10 is subjected to internal and external impact forces and deformed.

[0259] In some embodiments, referring to FIG. 7 , FIG. 12 and FIG. 14 , the first surface 64 is the surface of the pressure relief component 6 facing the interior of the housing 1 .

[0260] The first surface 64 is the outer surface of the pressure relief component 6 , and the second surface 65 is the inner surface of the pressure relief component 6 .

[0261] In this embodiment, the first surface 64 is the surface of the pressure relief component 6 facing the interior of the housing 1, so that the second groove 62 is arranged on the inner side of the pressure relief component 6. On the one hand, during the outward flipping and opening of the predetermined pressure relief area 63, the first groove side 621 and the second groove side 622 of the second groove 62 are unlikely to abut each other, which helps to increase the opening area of ​​the predetermined pressure relief area 63. On the other hand, the second groove 62 is not exposed to the outside of the battery cell 10, reducing the risk of oxidation and corrosion of the pressure relief component 6 in the area of ​​the second groove 62. In addition, when the first groove 61 is arranged on the first surface 64, the first surface 64 is the surface of the pressure relief component 6 facing the interior of the housing 1, so that the first groove 61 is arranged inside the pressure relief component 6, so that the first groove 61 is not exposed to the outside of the battery cell 10, reducing the risk of oxidation and corrosion of the pressure relief component 6 in the area of ​​the first groove 61.

[0262] In other embodiments, the first surface 64 is the surface of the pressure relief component 6 facing the outside of the housing 1 .

[0263] The first surface 64 is the outer surface of the pressure relief component 6 , and the second surface 65 is the inner surface of the pressure relief component 6 .

[0264] In this embodiment, the first surface 64 is the surface of the pressure relief component 6 facing the exterior of the housing 1. This allows the second groove 62 to be positioned outside the pressure relief component 6, facilitating the machining of the second groove 62 on the exterior of the battery cell 10. This reduces the difficulty in molding the second groove 62, thereby improving the production efficiency of the battery cell 10. Because the angle a formed between the first groove side 621 and the first surface 64 is smaller than the angle b formed between the second groove side 622 and the first surface 64, the angle between the first groove side 621 and the second groove side 622 is increased, thereby increasing the opening angle of the predetermined pressure relief area 63 when the predetermined pressure relief area 63 is turned outward and abuts the first groove side 621 and the second groove side 622. Furthermore, when the first groove 61 is positioned on the first surface 64, the first surface 64 is the surface of the pressure relief component 6 facing the exterior of the housing 1. This allows the first groove 61 to be positioned outside the pressure relief component 6, facilitating the machining of the first groove 61 on the exterior of the battery cell 10. This reduces the difficulty in molding the first groove 61, thereby improving the production efficiency of the battery cell 10.

[0265] In some embodiments, referring to Figures 15 and 16 , Figure 15 is a partial view of a housing 1 provided in other embodiments of the present application; Figure 16 is a cross-sectional view taken along line GG of the housing 1 shown in Figure 15 . The first groove 61 includes a first groove section 611 and a second groove section 612 . The first groove section 611 and the second groove section 612 are connected, and the first groove section 611 and the second groove section 612 together define at least one predetermined pressure relief area 63 .

[0266] The first slot segment 611 and the second slot segment 612 are two slot segments in the first groove 61. The first slot segment 611 and the second slot segment 612 can collectively define one or more predetermined pressure relief zones 63. The first slot segment 611 and the second slot segment 612 can be linear slots extending along a linear trajectory, or non-linear slots extending along a non-linear trajectory, such as an arcuate slot extending along an arcuate trajectory. If both the first slot segment 611 and the second slot segment 612 extend along a linear trajectory, the first slot segment 611 and the second slot segment 612 can be arranged at an acute angle, a right angle, or an obtuse angle. The first slot segment 611 and the second slot segment 612 can be connected end-to-end to form a V-shaped, L-shaped, or other structure, and the first slot segment 611 and the second slot segment 612 can define one predetermined pressure relief zone 63. The first slot segment 611 and the second slot segment 612 can also be arranged crosswise to form an X-shaped structure, and the first slot segment 611 and the second slot segment 612 can define four predetermined pressure relief zones 63.

[0267] As an example, in the embodiments shown in Figures 15 and 16, a first slot segment 611 and a second slot segment 612 are connected to form a V-shaped structure, defining a predetermined pressure relief zone 63. A first groove 61 is provided on a second surface 65, and a second groove 62 is provided on a first surface 64. A line connecting the end of the first slot segment 611 away from the second slot segment 612 and the end of the second slot segment 612 away from the first slot segment 611 within the second surface 65 is a first line W. The first line W, the second slot segment 612, and the second slot segment 612 are connected end to end to enclose the predetermined pressure relief zone 63. In Figure 15, the triangular shaded portion represents the predetermined pressure relief zone 63.

[0268] It should be noted that, in the embodiment where the first groove 61 is a multi-stage groove structure, both the first groove section 611 and the second groove section 612 are multi-stage groove structures.

[0269] In this embodiment, at least one predetermined pressure relief area 63 is jointly defined by the first groove section 611 and the second groove section 612. The first groove 61 of this structure has a simple structure, and the stress at the position where the first groove section 611 and the second groove section 612 are connected is more concentrated and weaker. Therefore, when the battery cell 10 thermally runs away, the pressure relief component 6 can quickly split from the first groove section 611 and the second groove section 612 after the position where the first groove section 611 and the second groove section 612 are connected is split, so that the predetermined pressure relief area 63 is opened more quickly and the pressure is relieved in time.

[0270] In some embodiments, please continue to refer to Figures 10 and 11. The first groove 61 includes a first groove section 611, a second groove section 612 and a third groove section 613. The second groove section 612 and the third groove section 613 are arranged opposite to each other. The first groove section 611 is arranged opposite to the second groove 62. The first groove section 611 connects the second groove section 612 and the third groove section 613. Along the width direction Z of the second groove, the first groove section 611 and the second groove 62 are spaced apart. The first groove section 611, the second groove section 612 and the third groove section 613 jointly define at least one predetermined pressure relief area 63.

[0271] The first slot segment 611, the second slot segment 612, and the third slot segment 613 can collectively define a predetermined pressure relief area 63 or multiple predetermined pressure relief areas 63. The first slot segment 611, the second slot segment 612, and the third slot segment 613 are three slot segments in the first groove 61. The first slot segment 611, the second slot segment 612, and the third slot segment 613 can be linear slots extending along a linear trajectory, or non-linear slots extending along a non-linear trajectory, for example, arcuate slots extending along an arcuate trajectory. If the first slot segment 611, the second slot segment 612, and the third slot segment 613 all extend along a linear trajectory, the first slot segment 611 and the second slot segment 612 can be arranged at an acute angle, a right angle, or an obtuse angle. The first slot segment 611 and the second slot segment 612 can be arranged at an acute angle, a right angle, or an obtuse angle. The second slot segment 612 and the third slot segment 613 can be arranged parallel to each other, or the extension line of the second slot segment 612 and the extension line of the third slot segment 613 can intersect.

[0272] The first trough section 611 connects the second trough section 612 and the third trough section 613. Either end of the first trough section 611 is connected to the second trough section 612 and the third trough section 613, respectively. Alternatively, at least one of the second trough section 612 and the third trough section 613 is connected to a position offset from the end of the first trough section 611, such that at least one of the second trough section 612 and the third trough section 613 is located between the two ends of the first trough section 611. The second trough section 612 can be connected to the first trough section 611 at one end or between the two ends of the second trough section 612. The third trough section 613 can be connected to the first trough section 611 at one end or between the two ends of the third trough section 613. The first trough section 611, the second trough section 612, and the third trough section 613 can form a U-shaped, N-shaped, or H-shaped structure. If the first slot section 611, the second slot section 612, and the third slot section 613 form a U-shaped structure, the first slot section 611, the second slot section 612, and the third slot section 613 jointly define a predetermined pressure relief area 63. If the first slot section 611, the second slot section 612, and the third slot section 613 form an N-shaped or H-shaped structure, the first slot section 611, the second slot section 612, and the third slot section 613 jointly define two predetermined pressure relief areas 63.

[0273] As an example, in the embodiment shown in Figures 10 and 11, the first groove section 611, the second groove section 612 and the third groove section 613 form an H-shaped structure, there are two predetermined pressure relief areas 63, the first groove 61 is provided on the second surface 65, the second groove 62 is provided on the first surface 64, and the line connecting one end of the second groove section 612 and one end of the third groove section 613 in the second surface 65 forms a first connecting line W, and the line connecting the other end of the second groove section 612 and the other end of the third groove section 613 in the second surface 65 forms a first connecting line W. The line forms another first connecting line W, the first slot segment 611 is located between the two first connecting lines W, a portion of the second slot segment 612, the first slot segment 611, a portion of the third slot segment 613 and a first connecting line W are connected end to end to enclose a predetermined pressure relief area 63, and another portion of the second slot segment 612, the first slot segment 611, another portion of the third slot segment 613 and another first connecting line W are connected end to end to enclose another predetermined pressure relief area 63. The two shaded parts shown in Figure 10 are the two predetermined pressure relief areas 63.

[0274] In this embodiment, the first groove section 611 connects the second groove section 612 and the third groove section 613, making the intersection of the first and second groove sections 611, 612, and the connection between the first and third groove sections 611, 613, weaker, making it easier to rupture and open the predetermined pressure relief area 63 for pressure relief. The second groove section 612 and the third groove section 613 are arranged opposite each other, and the first groove section 611 and the second groove 62 are spaced apart along the width direction Z of the second groove. The first, second, and third groove sections 611, 612, and 613 collectively define at least one predetermined pressure relief area 63, further increasing the open area of ​​the predetermined pressure relief area 63, thereby increasing the pressure relief area of ​​the battery cell 10 and improving the pressure relief rate of the battery cell 10.

[0275] In some embodiments, the connection position between the second slot segment 612 and the first slot segment 611 deviates from the two ends of the second slot segment 612, and the connection position between the third slot segment 613 and the first slot segment 611 deviates from the two ends of the third slot segment 613, so that a predetermined pressure relief area 63 is formed on both sides of the first slot segment 611.

[0276] The connection position between the second slot segment 612 and the first slot segment 611 is offset from the two ends of the second slot segment 612. That is, the connection position between the second slot segment 612 and the first slot segment 611 is not located at either end of the second slot segment 612. Along the extension direction of the second slot segment 612, the connection position between the second slot segment 612 and the first slot segment 611 is located between the two ends of the second slot segment 612. The connection position between the second slot segment 612 and the first slot segment 611 can be located at the midpoint of the second slot segment 612 or offset from the midpoint of the second slot segment 612.

[0277] The connection position between the third slot segment 613 and the first slot segment 611 is offset from the ends of the third slot segment 613. That is, the connection position between the third slot segment 613 and the first slot segment 611 is not located at either end of the third slot segment 613. Along the extension direction of the third slot segment 613, the connection position between the third slot segment 613 and the first slot segment 611 is located between the ends of the third slot segment 613. The connection position between the third slot segment 613 and the first slot segment 611 can be located at the midpoint of the third slot segment 613 or offset from the midpoint of the third slot segment 613.

[0278] It should be noted that, in the embodiment where the first groove 61 is a multi-stage groove structure, the first groove section 611 , the second groove section 612 and the third groove section 613 are all multi-stage groove structures.

[0279] In this embodiment, the connection position of the second groove section 612 and the first groove section 611 deviates from the two ends of the second groove section 612, and the connection position of the third groove section 613 and the first groove section 611 deviates from the two ends of the third groove section 613, so that the first groove section 611 of the first groove 61 is located between the two predetermined pressure relief areas 63. After the pressure relief component 6 is split along the first groove section 611, the two predetermined pressure relief areas 63 can be opened in a split manner to relieve pressure when the battery cell 10 is relieved of pressure, so that the two predetermined pressure relief areas 63 can be opened quickly, which is beneficial to improving the pressure relief rate of the battery cell 10.

[0280] In some embodiments, the first slot segment 611 extends along a straight line or an arcuate trajectory; and / or the second slot segment 612 extends along a straight line or an arcuate trajectory; and / or the third slot segment 613 extends along a straight line or an arcuate trajectory. If the first slot segment 611 extends along a straight line, the first slot segment 611 is a straight slot, which can reduce the difficulty of forming the first slot segment 611.

[0281] As an example, in the embodiment shown in FIG. 10 , the first slot segment 611 , the second slot segment 612 and the third slot segment 613 all extend along straight lines, and the second slot segment 612 and the third slot segment 613 are both perpendicular to the first slot segment 611 .

[0282] If the first groove section 611 extends along an arc trajectory, the first groove section 611 is an arc-shaped groove, and the pressure relief component 6 is more likely to split along the first groove section 611 when the battery cell 10 releases pressure, thereby enabling the predetermined pressure relief area 63 to open more quickly. If the second groove section 612 extends along a straight trajectory, the second groove section 612 is a straight groove, which can reduce the difficulty of forming the second groove section 612. If the second groove section 612 extends along an arc trajectory, the second groove section 612 is an arc-shaped groove, and the pressure relief component 6 is more likely to split along the second groove section 612 when the battery cell 10 releases pressure, thereby enabling the predetermined pressure relief area 63 to open more quickly. If the third groove section 613 extends along a straight trajectory, the third groove section 613 is a straight groove, which can reduce the difficulty of forming the third groove section 613. If the third groove section 613 extends along an arc trajectory, the third groove section 613 is an arc-shaped groove, and the pressure relief component 6 is more likely to break along the third groove section 613 when the battery cell 10 releases pressure, thereby achieving faster opening of the predetermined pressure relief area 63.

[0283] In some embodiments, please refer to Figures 17 and 18, Figure 17 is a partial view of the housing 1 provided in some embodiments of the present application; Figure 18 is a HH cross-sectional view of the housing 1 shown in Figure 17. The first groove 61 extends along an arc trajectory.

[0284] The central angle of the first groove 61 may be less than 15°, 30°, 45°, 60°, 90°, 120°, 150°, 180°, 210°, 240°, 270°, 300°, 330°, etc.

[0285] As an example, in the embodiments shown in Figures 17 and 18, the first groove 61 is arranged on the second surface 65, the second groove 62 is arranged on the first surface 64, and the line connecting the two ends of the first groove 61 forms a first line W. The first groove 61 and the first line W are connected end to end to enclose a predetermined pressure relief area 63.

[0286] In this embodiment, the first groove 61 extends along an arc track. The first groove 61 is an arc-shaped groove. The first groove 61 of this structure only includes one groove segment, which simplifies the structure of the first groove 61.

[0287] In some embodiments, referring to Figures 10, 15, and 17, the second groove 62 extends along a straight line. The second groove 62 is a straight groove with a simple structure and is easy to process and form.

[0288] In some embodiments, please refer to FIG19 , which is an exploded view of the housing 1 (one end of the housing 11 is open, and the end cover 12 is a pressure relief component 6 ) provided in some embodiments of the present application. The pressure relief component 6 is integrally formed with the first wall portion 13 .

[0289] It is understood that a portion of the first wall portion 13 can serve as the pressure relief component 6, or the entire first wall portion 13 can serve as the pressure relief component 6, that is, the first wall portion 13 and the pressure relief component 6 are the same component. The first groove 61 and the second groove 62 are both provided in the first wall portion 13. The thickness direction X of the first wall portion corresponds to the thickness direction of the pressure relief component 6. One of the first surface 64 and the second surface 65 of the pressure relief component 6 is the inner surface of the first wall portion 13, and the other is the outer surface of the first wall portion 13.

[0290] In this embodiment, the pressure relief component 6 is integrally formed with the first wall portion 13, so that the first groove 61 and the second groove 62 can be directly formed on the first wall portion 13, forming an integrated pressure relief structure with higher reliability, eliminating the installation process of the pressure relief component 6, and having better economy.

[0291] In some embodiments, please refer to FIG. 20 , which is an exploded view of a housing 1 (one end of the housing 11 is open, the end cap 12 forms a first wall portion 13, and the pressure relief component 6 is mounted on the first wall portion 13) provided in some embodiments of the present application. The pressure relief component 6 is provided separately from the first wall portion 13 and is mounted on the first wall portion 13.

[0292] The pressure relief component 6 and the housing 1 are separate components. The pressure relief component 6 can be manufactured separately and then mounted on the first wall portion 13. The pressure relief component 6 can be mounted on the first wall portion 13 by welding, riveting, bonding, or other methods. As an example, the first wall portion 13 is provided with a pressure relief hole 131. The pressure relief component 6 covers the pressure relief hole 131 and is welded to the first wall portion 13.

[0293] In this embodiment, the pressure relief component 6 is a component independent of the housing 1 , and the pressure relief component 6 and the housing 1 can be produced and assembled separately, with low production difficulty and high efficiency.

[0294] In some embodiments, the first groove 61 is stamped and formed on the pressure relief component 6 .

[0295] It is understood that the first groove 61 is formed in the pressure relief component 6 by stamping. If the first groove 61 is a single-stage groove structure, when forming the first groove 61 in the pressure relief component 6, the first wall portion 13 can be stamped once to stamp out the first groove 61 in the pressure relief component 6. If the first groove 61 is a multi-stage groove structure, when forming the first groove 61 in the pressure relief component 6, the pressure relief component 6 can be stamped multiple times, each time stamping out a single stage of the groove, and finally forming the first groove 61 after multiple stampings. It is understood that in the embodiment where the pressure relief component 6 and the first wall portion 13 are integrally formed, the first groove 61 is stamped and formed in the first wall portion 13.

[0296] In this embodiment, the first groove 61 is stamped and formed on the pressure relief component 6 . The molding method of the first groove 61 is simple, which is beneficial to reducing the production cost of the battery cell 10 .

[0297] In some embodiments, the second groove 62 is stamped and formed on the pressure relief component 6 .

[0298] It is understandable that the second groove 62 is formed in the pressure relief component 6 by stamping. In the embodiment where the pressure relief component 6 and the first wall portion 13 are integrally formed, the second groove 62 is stamped in the first wall portion 13 .

[0299] In this embodiment, the second groove 62 is stamped and formed on the pressure relief component 6 . The second groove 62 is formed in a simple manner, which is beneficial for reducing the production cost of the battery cell 10 .

[0300] In some embodiments, the first wall portion 13 is a rectangular wall portion, and the first groove 61 and the second groove 62 are arranged along the width direction of the first wall portion 13 .

[0301] The housing 1 can be in the shape of a rectangular parallelepiped, and the first wall 13 can be any rectangular wall in the housing 1. The first wall 13 is a rectangular wall, that is, when viewed along the thickness direction X of the first wall, the first wall 13 is generally rectangular. The length of the first wall 13 is greater than the width of the first wall 13.

[0302] The first groove 61 and the second groove 62 are arranged along the width direction of the first wall portion 13. The first groove 61 and the second groove 62 can be spaced apart along the width direction of the first wall portion 13, or the projection of the first groove 61 along the thickness direction X of the first wall portion and the projection of the second groove 62 along the thickness direction X of the first wall portion are just connected in the width direction of the first wall portion 13. Taking the H-shaped first groove 61 as an example, the second groove section 612 and the third groove section 613 of the first groove 61 may both be at a certain distance from the second groove 62 along the width direction of the first wall portion 13, so that the first groove 61 and the second groove 62 are spaced apart along the width direction of the first wall portion 13. Alternatively, the projection of at least one of the second groove section 612 and the third groove section 613 of the first groove 61 along the thickness direction X of the first wall portion at one end of the extension direction just extends along the width direction of the first wall portion 13 to the projection of the second groove 62 along the thickness direction X of the first wall portion, so that the projection of the first groove 61 along the thickness direction X of the first wall portion and the projection of the second groove 62 along the thickness direction X of the first wall portion just connect in the width direction of the first wall portion 13.

[0303] As an example, the width direction of the first wall portion 13 is parallel to the width direction Z of the second groove.

[0304] In this embodiment, the first groove 61 and the second groove 62 are arranged along the width direction of the first wall portion 13, so that the second groove 62 is closer to the edge of the first wall portion 13 in the width direction of the first wall portion 13. This provides greater strength in the area of ​​the pressure relief member 6 where the second groove 62 is provided, thereby reducing the risk of the pressure relief member 6 cracking along the second groove 62 when the battery cell 10 releases pressure. Furthermore, during normal use of the battery cell 10, the battery cell 10 expands more in the width direction of the first wall portion 13 than in the length direction of the first wall portion 13, and this expansion of the battery cell 10 in the width direction of the first wall portion 13 has a greater impact on the pressure relief member 6. Since the first groove 61 and the second groove 62 are arranged along the width direction of the first wall portion 13, the second groove 62 can effectively absorb the deformation energy of the battery cell 10 when it expands and deforms in the width direction of the first wall portion 13, thereby reducing the impact of the expansion of the battery cell 10 in the width direction of the first wall portion 13 on the pressure relief member 6.

[0305] 19 and 20 , the housing 1 includes a shell 11 and an end cap 12 . The shell 11 has an opening at at least one end. The end cap 12 corresponds to the opening and closes the opening. At least one end cap 12 is a first wall portion 13 .

[0306] The housing 11 may have only one opening, for example, only one end of the housing 11 may have an opening; the housing 11 may also have multiple openings, for example, openings at both opposite ends of the housing 11. The number of end caps 12 is the same as the number of openings of the housing 11. It is understood that if the housing 11 has only one opening, there is only one end cap 12, which serves as the first wall portion 13; if the housing 11 has two openings, there are two end caps 12, and one end cap 12 may serve as the first wall portion 13, or both end caps 12 may serve as the first wall portion 13.

[0307] In an embodiment where the housing 11 is open at one end, the positive electrode terminal and the negative electrode terminal can be provided on the end cap 12, and the positive and negative electrode tabs can be formed at the end of the electrode assembly 2 facing the end cap 12, so as to facilitate electrical connection with the positive and negative electrode terminals, respectively. In an embodiment where openings are formed at both opposing ends of the housing 11, the positive electrode terminal can be provided at one end cap 12, and the negative electrode terminal can be provided at the other end cap 12, and the positive and negative electrode tabs can be formed at opposing ends of the electrode assembly 2, so as to facilitate electrical connection between the positive tab and the positive electrode terminal, and between the negative tab and the negative electrode terminal, respectively.

[0308] In the embodiment shown in FIG19 , an opening is formed at one end of the housing 11, and the end cap 12 forms a first wall portion 13 (not shown in FIG19 ). The first wall portion 13 serves as the pressure relief component 6. In the embodiment shown in FIG20 , an opening is formed at one end of the housing 11, and the end cap 12 forms a first wall portion 13. The pressure relief component 6 is mounted on the first wall portion 13.

[0309] In this embodiment, at least one end cover 12 in the shell 11 is the first wall portion 13, so that at least one end cover 12 has a pressure relief function, and the difficulty of forming the first groove 61 and the second groove 62 on the end cover 12 or the difficulty of installing the pressure relief component 6 is lower.

[0310] In some embodiments, please refer to Figures 21 and 22. Figure 21 is an exploded view of the housing 1 provided in some embodiments of the present application (an opening is formed at one end of the housing 11, the housing 11 includes a first wall portion 13, and the pressure relief component 6 is the first wall portion 13); Figure 22 is an exploded view of the housing 1 provided in some embodiments of the present application (an opening is formed at one end of the housing 11, the housing 11 includes a first wall portion 13, and the pressure relief component 6 is installed on the first wall portion 13). The housing 1 includes a housing 11 and an end cover 12. An opening is formed at least at one end of the housing 11. The end cover 12 corresponds to the opening one-to-one, and the end cover 12 closes the opening. Among them, at least one wall portion in the housing 11 is the first wall portion 13.

[0311] The housing 11 may have only one opening, for example, only one end of the housing 11 may have an opening; the housing 11 may also have multiple openings, for example, openings at both opposing ends of the housing 11. The number of end caps 12 is the same as the number of openings in the housing 11. It is understood that if the housing 11 has only one opening, there is one end cap 12; if the housing 11 has two openings, there are two end caps 12. In embodiments where the housing 11 has an opening at one end, the positive and negative electrode terminals may be disposed on the end cap 12, and the positive and negative tabs may be formed on the end of the electrode assembly 2 facing the end cap 12 to facilitate electrical connection with the positive and negative electrode terminals, respectively. In embodiments where openings are formed at both opposing ends of the housing 11, the positive electrode terminal may be disposed on one end cap 12, and the negative electrode terminal may be disposed on the other end cap 12. The positive and negative tabs may be formed on opposing ends of the electrode assembly 2 to facilitate electrical connection with the positive electrode terminal and with the negative electrode terminal, respectively. In the housing 11 , one wall portion may serve as the first wall portion 13 , or a plurality of wall portions may serve as the first wall portion 13 .

[0312] In this embodiment, at least one wall portion of the housing 11 is a first wall portion 13, providing the housing 11 with a pressure relief function. When the battery cell 10 releases pressure, the exhaust from the interior of the battery cell 10 is less likely to affect external components outside the end cap 12, reducing the risk of damage to these external components from the exhaust. These external components may include a busbar connected to the electrode terminals, a temperature sensor, a voltage sensor, and the like. Exhausts include, but are not limited to, electrolyte, dissolved or split positive and negative electrode sheets, separator fragments, high-temperature, high-pressure gases generated by the reaction, and flames.

[0313] In some embodiments, please continue to refer to Figures 21 and 22. Only one end of the shell 11 is formed with an opening, and the wall portion of the shell 11 opposite to the end cover 12 is the first wall portion 13.

[0314] As an example, the housing 11 is rectangular and further includes four side walls, which are arranged around the first wall portion 13. The four side walls and the first wall portion 13 together define the space inside the housing 11. In the embodiment shown in FIG21 , an opening is formed at one end of the housing 11. The wall portion of the housing 11 opposite the end cap 12 is the first wall portion 13, and the pressure relief component 6 is the first wall portion 13. In the embodiment shown in FIG22 , an opening is formed at one end of the housing 11. The wall portion of the housing 11 opposite the end cap 12 is the first wall portion 13, and the pressure relief component 6 is mounted on the first wall portion 13.

[0315] In this embodiment, the housing 11 is open at one end, simplifying the structure of the entire battery cell 10. The first wall 13 is the wall of the housing 11 opposite the end cap 12, and can achieve directional pressure relief from the bottom of the housing 11.

[0316] In some embodiments, please refer to FIG23 , which is an exploded view of a battery cell 10 provided in some other embodiments of the present application. Openings are formed at opposite ends of the housing 11 , and at least one wall portion of the housing 11 is a first wall portion 13 .

[0317] In the housing 11 , one wall portion or multiple walls may be the first wall portion 13 . The pressure relief component 6 may be the first wall portion 13 , or may be mounted on the first wall portion 13 .

[0318] As an example, the housing 11 is in the shape of a rectangular parallelepiped and includes four walls, which are connected end to end and together define the space inside the housing 11. Two opposing walls are large-area walls, and the other two are small-area walls. The outer surfaces of the large-area walls are larger than the outer surfaces of the small-area walls. One or two of the small-area walls in the housing 11 are first walls 13.

[0319] In this embodiment, the housing 11 has openings at both opposing ends. The electrode assembly 2 can be assembled into the housing 11 through either opening, which reduces the difficulty of assembling the battery cell 10 and improves the assembly quality of the battery cell 10. This structure of the housing 11 allows for a longer length (openings are formed at both ends of the housing 11 in the longitudinal direction), which helps increase the capacity of the battery cell 10.

[0320] In some embodiments, the pressure relief component 6 is made of steel.

[0321] The steel material can be carbon steel, alloy steel, stainless steel, etc.

[0322] It is understood that in the embodiment where the pressure relief component 6 and the first wall portion 13 are integrally formed, the material of the first wall portion 13 includes steel. If the first wall portion 13 is the end cap 12, the end cap 12 can be made of steel; if the first wall portion 13 is a wall portion in the housing 11, the housing 11 can be made of steel.

[0323] In this embodiment, steel has the characteristic of high strength, and the pressure relief component 6 made of steel has greater strength. Under the condition of a constant burst pressure of the battery cell 10, the pressure relief component 6 can be made thinner, thereby reducing the volume of the pressure relief component 6. In the embodiment where the pressure relief component 6 is integrally formed with the first wall portion 13, the first wall portion 13 is made of steel and can be made thinner. Under the condition of a constant volume of the outer shell 1, the volume of the outer shell 1 can be increased to provide more space for the electrode assembly 2, which is conducive to improving the volumetric energy density of the battery cell 10.

[0324] In some embodiments, the steel material is carbon steel or stainless steel.

[0325] Carbon steel can be low carbon steel, medium carbon steel or high carbon steel.

[0326] In some embodiments, the pressure relief component 6 is made of aluminum alloy.

[0327] It is understood that in the embodiment where the pressure relief component 6 and the first wall portion 13 are integrally formed, the material of the first wall portion 13 includes an aluminum alloy. If the first wall portion 13 is the end cap 12, the end cap 12 can be made of an aluminum alloy; if the first wall portion 13 is a wall portion in the housing 11, the housing 11 can be made of an aluminum alloy.

[0328] Aluminum alloy has the characteristics of light weight and good ductility, and it is easier to process the first groove 61 and the second groove 62 on the pressure relief component 6. In the embodiment where the pressure relief component 6 and the first wall portion 13 are integrally formed, the first wall portion 13 is made of aluminum alloy, which can effectively reduce the difficulty of forming the first wall portion 13. Since aluminum alloy has good ductility, it is easier to pile materials in the predetermined pressure relief area 63 when forming the first groove 61. However, making the angle between the first groove side 621 and the first surface 64 smaller than the angle between the second groove side 622 and the first surface 64 can effectively reduce the impact of the pile of materials in the predetermined pressure relief area 63 on the performance of the battery cell 10, thereby improving the service life of the battery cell 10.

[0329] In some embodiments, the aluminum alloy includes the following components in mass percentage: aluminum ≥ 99.6%, copper ≤ 0.05%, iron ≤ 0.35%, magnesium ≤ 0.03%, manganese ≤ 0.03%, silicon ≤ 0.25%, titanium ≤ 0.03%, vanadium ≤ 0.05%, zinc ≤ 0.05%, and other individual elements ≤ 0.03%.

[0330] This aluminum alloy belongs to the third series aluminum, has lower hardness and better forming ability, reduces the processing difficulty of the first groove 61 and the second groove 62, is conducive to improving the processing accuracy of the first groove 61 and the second groove 62, and improves the pressure relief consistency of the pressure relief component 6.

[0331] In some embodiments, the aluminum alloy includes the following components in mass percentage: aluminum ≥ 96.7%, 0.05% ≤ copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other individual element components ≤ 0.05%, and the total composition of other elements ≤ 0.15%.

[0332] This aluminum alloy belongs to the fifth series aluminum. The pressure relief component 6 made of this aluminum alloy has higher hardness, greater strength, and good anti-destruction ability. The embodiment of the present application provides a battery 100, including the battery cell 10 provided by any of the above embodiments.

[0333] An embodiment of the present application provides a battery 100 , comprising the battery cell 10 provided in any one of the above embodiments.

[0334] An embodiment of the present application provides an electrical device, comprising a battery cell 10 provided by any one of the above embodiments, and the battery cell 10 is used to provide electrical energy to the electrical device.

[0335] The present embodiment further provides a battery cell 10, comprising a housing 1 and an electrode assembly 2, wherein the electrode assembly 2 has a positive tab and a negative tab, and the electrode assembly 2 is housed within the housing 1. The housing 1 is rectangular and comprises a shell 11 and an end cap 12. The shell 11 has an opening at one end, and the end cap 12 seals the opening. The end cap 12 is provided with a positive electrode terminal and a negative electrode terminal. The positive electrode terminal is electrically connected to the positive tab via a current collecting member 4, and the negative electrode terminal is electrically connected to the negative tab via another current collecting member 4.

[0336] Referring to Figures 9-12 , the wall of the housing 11 facing the end cap 12 is the pressure relief component 6 . The pressure relief component 6 is a rectangular wall. A first groove 61 is provided on the outer surface of the pressure relief component 6 , and two second grooves 62 are provided on the inner surface of the pressure relief component 6 . Along the width direction of the pressure relief component 6 , the first groove 61 is located between the two second grooves 62 , and the second grooves 62 are spaced apart from the first groove 61 . The minimum residual thickness of the first groove 61 is less than the minimum residual thickness of the second groove 62 . The first groove 61 has an H-shaped structure and includes a first groove section 611, a second groove section 612, and a third groove section 613. The first, second, and third groove sections 611, 612, 613 all extend along straight lines. The second and third groove sections 612, 613 are arranged in parallel. The first groove section 611 connects the second and third groove sections 612, 613. The second and third groove sections 612, 613 are both perpendicular to the first groove section 611. The connection between the first and second groove sections 611, 612 is located at the midpoint of the second groove section 612, and the connection between the first and third groove sections 611, 613 is located at the midpoint of the third groove section 613. Along the thickness direction X of the first wall portion, the projection of the second groove 62 extends from both ends of the extension direction to form the second and third groove sections 612, 613, respectively. The first groove 61 is a stepped groove and includes two stages, each of which has an H-shaped structure. The first, second, and third groove sections 611, 612, and 613 collectively define two predetermined pressure relief areas 63. Each predetermined pressure relief area 63 corresponds to a second groove 62. The pressure relief component 6 is configured to rupture along at least a portion of the first groove 61 when pressure is released from the battery cell 10. The second groove 62 is configured to guide at least a portion of the predetermined pressure relief area 63 to flip, thereby opening at least a portion of the predetermined pressure relief area 63. Along the width direction Z of the second groove, the second groove 62 includes a first groove side surface 621 and a second groove side surface 622, which are oppositely disposed and connected to the inner surface of the pressure relief component 6. The first groove side surface 621 is closer to the predetermined pressure relief area 63 than the second groove side surface 622. The first groove side surface 621 and the inner surface of the pressure relief component 6 form an angle a, and the second groove side surface 622 and the inner surface of the pressure relief component 6 form an angle b, satisfying the following conditions: 90°≤a<b<180°. The width direction Z of the second groove is perpendicular to the thickness direction X of the first wall portion.

[0337] In such a battery cell 10, since a<b, the angle between the first groove side 621 and the first surface 64 is reduced, which can reduce the amount of excess material squeezed out when forming the second groove 62 and diffused to the predetermined pressure relief area 63, and reduce the height of the pile bulge formed by the excess material squeezed out from the area where the second groove 62 is set in the pressure relief component 6 and accumulated in the predetermined pressure relief area 63, thereby improving the flatness of the surface of the predetermined pressure relief area 63, reducing the risk of the predetermined pressure relief area 63 opening prematurely due to poor surface flatness, and improving the service life of the battery cell 10.

[0338] 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.

[0339] The above embodiments are intended only to illustrate the technical solutions of this application and are not intended to limit this application. Those skilled in the art will appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application are intended to be within the scope of protection of this application.

Claims

1. A battery cell, comprising: A housing, including a first wall portion; A pressure relief component disposed on the first wall portion, the pressure relief component being provided with a first groove and a second groove, the first groove defining at least one predetermined pressure relief area, the pressure relief component being configured to be able to crack along at least a part of the first groove when the battery cell relieves pressure, in the thickness direction of the first wall portion, the pressure relief component has opposite first and second surfaces, the second groove is recessed from the first surface towards the direction close to the second surface, the second groove is configured to guide at least a part of the predetermined pressure relief area to flip, so as to open at least a part of the predetermined pressure relief area; Wherein, in the width direction of the second groove, the second groove includes a first groove side surface and a second groove side surface which are oppositely arranged and connected to the first surface, the first groove side surface is closer to the predetermined pressure relief area than the second groove side surface, the angle formed by the first groove side surface and the first surface is a, and the angle formed by the second groove side surface and the first surface is b, satisfying: 90° ≤ a < b < 180°, and the width direction of the second groove is perpendicular to the thickness direction of the first wall portion.

2. The battery cell according to claim 1, wherein, 90° ≤ a ≤ 150°; and / or, 90° < b ≤ 170°.

3. The battery cell according to claim 1 or 2, wherein, The second groove further includes a first groove bottom surface connecting the first groove side surface and the second groove side surface, the second groove forms a first groove opening on the first surface, in the width direction of the second groove, the width of the first groove bottom surface is L1, and the width of the first groove opening is L2, satisfying: L1 < L2.

4. The battery cell according to claim 3, wherein, 0.05 mm ≤ L1 ≤ 0.3 mm; and / or, 0.4 mm ≤ L2 ≤ 1.2 mm.

5. The battery cell according to any one of claims 1-4, wherein, The minimum remaining thickness of the first groove is D1, and the minimum remaining thickness of the second groove is D2, satisfying: D1 < D2.

6. The battery cell according to claim 5, wherein, In the thickness direction of the first wall portion, the maximum groove depth of the first groove is H1, and the maximum groove depth of the second groove is H2, satisfying: H2 < H1.

7. The battery cell according to claim 5 or 6, wherein, 0.3 mm ≤ D2 ≤ 1.2 mm.

8. The battery cell according to any one of claims 1-7, wherein, The pressure relief component is provided with a plurality of the second grooves, the first groove defines a plurality of the predetermined pressure relief areas, and each of the predetermined pressure relief areas is correspondingly arranged with at least one of the second grooves.

9. The battery cell according to claim 8, wherein, Both the predetermined pressure relief area and the second groove are two; The first groove includes a first groove section, in the width direction of the second groove, the first groove section is located between the two second grooves, and the two predetermined pressure relief areas are respectively located on both sides of the first groove section, and the first groove side surface is closer to the first groove section than the second groove side surface.

10. The battery cell according to any one of claims 1-9, wherein, In the thickness direction of the first wall portion, the projection of the second groove does not overlap with the projection of the first groove.

11. The battery cell according to claim 10, wherein, In the width direction of the second groove, the second groove and the first groove are arranged at intervals.

12. The battery cell according to any one of claims 1-11, wherein, In the thickness direction of the first wall portion, both ends of the projection of the second groove along the extending direction respectively extend out of the two ends of the projection of the first groove.

13. The battery cell according to any one of claims 1-12, wherein, The first groove is recessed from the second surface towards the direction close to the first surface.

14. The battery cell according to claim 13, wherein, In the width direction of the second groove, at least part of the projection of the first groove overlaps with the second groove.

15. The battery cell according to claim 13 or 14, wherein, In the thickness direction of the first wall portion, the bottom surface of the second groove is closer to the second surface than the bottom surface of the first groove.

16. The battery cell according to any one of claims 13-15, wherein, In the thickness direction of the first wall portion, the maximum groove depth of the second groove is H2, and the minimum remaining thickness of the first groove is D1, satisfying: D1 < H2.

17. The battery cell according to any one of claims 13-16, wherein, The first groove includes multiple levels of grooves arranged in sequence in the direction from the second surface to the first surface. In the thickness direction of the first wall portion, in two adjacent levels of grooves, the level of groove farther from the second surface is arranged on the bottom surface of the level of groove closer to the second surface. Among them, the level of groove arranged on the second surface in the multiple levels of grooves is the first-level groove. In the width direction of the second groove, at least part of the projection of the second groove overlaps with the first-level groove.

18. The battery cell according to claim 17, wherein, In the thickness direction of the first wall portion, the bottom surface of the second groove is closer to the second surface than the bottom surface of the first-level groove.

19. The battery cell according to any one of claims 1-12, wherein, The first groove is recessed from the first surface towards the direction close to the second surface.

20. The battery cell according to claim 19, wherein, The first groove includes multiple levels of grooves arranged in sequence in the direction from the first surface to the second surface. In the thickness direction of the first wall portion, in two adjacent levels of grooves, the level of groove farther from the first surface is arranged on the bottom surface of the level of groove closer to the first surface. Among them, the level of groove arranged on the first surface in the multiple levels of grooves is the first-level groove. In the thickness direction of the first wall portion, the bottom surface of the first-level groove is closer to the first surface than the bottom surface of the second groove.

21. The battery cell according to claim 20, wherein, In the thickness direction of the first wall portion, the maximum groove depth of the second groove is H2, and the maximum groove depth of the first-level groove is H3, satisfying: H3 < H2.

22. The battery cell according to any one of claims 1-21, wherein, The first surface is the surface of the pressure relief component facing the interior of the housing.

23. The battery cell according to any one of claims 1-21, wherein, The first surface is the surface of the pressure relief component facing the exterior of the housing.

24. The battery cell according to any one of claims 1-23, wherein, The first groove includes a first groove section and a second groove section. The first groove section is connected to the second groove section, and the first groove section and the second groove section jointly define at least one of the predetermined pressure relief areas.

25. The battery cell according to any one of claims 1-23, wherein, The first groove includes a first groove section, a second groove section, and a third groove section. The second groove section and the third groove section are arranged oppositely. The first groove section connects the second groove section and the third groove section. In the width direction of the second groove, the first groove section is arranged at an interval from the second groove. The first groove section, the second groove section, and the third groove section jointly define at least one of the predetermined pressure relief areas.

26. The battery cell according to claim 25, wherein, The connection position of the second groove section and the first groove section deviates from both ends of the second groove section, and the connection position of the third groove section and the first groove section deviates from both ends of the third groove section, so that the predetermined pressure relief areas are formed on both sides of the first groove section.

27. The battery cell according to claim 25 or 26, wherein The first groove section extends along a straight or arc trajectory; and / or, the second groove section extends along a straight or arc trajectory; and / or, the third groove section extends along a straight or arc trajectory.

28. The battery cell according to any one of claims 1-8 and 10-23, wherein, The first groove extends along an arc trajectory.

29. The battery cell according to any one of claims 1-28, wherein, The second groove extends along a straight trajectory.

30. The battery cell according to any one of claims 1-29, wherein, The pressure relief component is integrally formed with the first wall portion; or, the pressure relief component is separately provided from the first wall portion, and the pressure relief component is installed on the first wall portion.

31. The battery cell according to any one of claims 1-30, wherein, The first groove is formed by stamping on the pressure relief component; and / or, the second groove is formed by stamping on the pressure relief component.

32. The battery cell according to any one of claims 1-31, wherein, The first wall portion is a rectangular wall portion, and the first groove and the second groove are arranged along the width direction of the first wall portion.

33. The battery cell according to any one of claims 1-32, wherein, The housing includes: A housing body having an opening formed at at least one end; End caps corresponding to the openings one by one, and the end caps close the openings; Wherein, at least one of the end caps is the first wall portion.

34. The battery cell according to any one of claims 1-32, wherein, The housing includes: A housing body having an opening formed at at least one end; End caps corresponding to the openings one by one, and the end caps close the openings; Wherein, at least one wall portion of the housing body is the first wall portion.

35. The battery cell according to claim 34, wherein, The housing body has the opening formed only at one end, and the wall portion of the housing body opposite to the end cap is the first wall portion.

36. The battery cell according to claim 34, wherein, Openings are formed at both opposite ends of the housing body, and at least one wall portion of the housing body is the first wall portion.

37. The battery cell according to any one of claims 1-36, wherein, The material of the pressure relief component includes steel material.

38. The battery cell according to claim 37, wherein, The steel material is carbon steel or stainless steel.

39. The battery cell according to any one of claims 1-36, wherein, The material of the pressure relief component includes aluminum alloy.

40. The battery cell according to claim 39, wherein, The aluminum alloy includes the following components by mass percentage: aluminum ≥ 99.6%, copper ≤ 0.05%, iron ≤ 0.35%, magnesium ≤ 0.03%, manganese ≤ 0.03%, silicon ≤ 0.25%, titanium ≤ 0.03%, vanadium ≤ 0.05%, zinc ≤ 0.05%, and other single elements ≤ 0.03%.

41. The battery cell according to claim 39, wherein, The aluminum alloy includes the following components by mass percentage: aluminum ≥ 96.7%, 0.05% ≤ copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other single element components ≤ 0.05%, and other element total components ≤ 0.15%.

42. A battery, comprising a battery cell according to any one of claims 1-41.

43. An electrical device, comprising a battery cell according to any one of claims 1-41, and the battery cell is used to supply electrical energy to the electrical device.

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