Battery monomer, battery and electric equipment

Abstract

The embodiment of the utility model provides a battery monomer, a battery and electric equipment. The battery monomer comprises a shell, the shell is provided with a first wall part, the first wall part is provided with a first groove and a second groove, the first groove defines at least one preset pressure relief area, the first wall part is configured to be capable of cracking along at least one part of the first groove when the battery monomer is subjected to pressure relief, and the first wall part is provided with a first surface and a second surface which are opposite to each other; the second groove is arranged on the first surface, and the second groove is used for guiding at least one part of the preset pressure relief area to turn over. The second groove comprises a first groove side face and a second groove side face which are oppositely arranged, the first groove side face is closer to the preset pressure relief area than the second groove side face, and the angle between the first groove side face and the first surface is smaller than that between the second groove side face and the first surface. The risk that the predetermined pressure relief area is opened in advance due to poor surface smoothness can be reduced, and the service life of the single battery is prolonged.

Description

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 cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.

[0003] For general battery cells, a pressure relief component is provided in the battery cell. When the battery cell is in thermal runaway, the pressure inside the battery cell is released through the pressure relief component to improve the reliability of the battery cell. In battery technology, not only the reliability of the battery cell needs to be considered, but also the service life of the battery cell. Therefore, how to improve the service life of the battery cell is an urgent problem to be solved in battery technology. Utility Model Content

[0004] The embodiments of the present application provide a battery cell, a battery and an electrical device, which can effectively improve the flatness of the surface of a pressure relief component.

[0005] In a 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, 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 arranged oppositely 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 first groove side surface being at an angle a to the first surface, the second groove side surface being at an angle b to the first surface, satisfying: 90°≤a<b<180°, and the width direction of the second groove being perpendicular to the thickness direction of the first wall portion.

[0006] In the above technical solution, the pressure relief component is provided with a first groove, and the first groove defines at least one predetermined pressure relief area, so that the pressure relief component can be split along at least a part of the first groove when the battery cell is relieved of pressure, so as to open the predetermined pressure relief area, so as to release the internal pressure of the battery cell. The pressure relief component is also provided with a second groove, and the second groove can 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 for pressure relief. The second groove plays an auxiliary role in 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, so that the predetermined pressure relief area can be opened more quickly in the process of the pressure relief component splitting along the first groove, and improving 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 extruded when forming the second groove and diffused to the predetermined pressure relief area, and reduce the height of the pile bulge formed by the excess material extruded from the area where the second groove of the pressure relief component is set in the predetermined pressure relief area. The flatness of the surface of the predetermined pressure relief area is improved, the risk of the predetermined pressure relief area opening prematurely due to poor surface flatness is reduced, and the service life of the battery cell is improved.

[0007] In some embodiments, 90°≤a≤150°. The influence of the side surface of the first groove on the molding tool is reduced, so that the molding tool is easier to be removed from the second groove, and the molding difficulty of the second groove is reduced.

[0008] In some embodiments, 90°<b≤170°. The influence of the side surface of the second groove on the molding tool is reduced, so that the molding tool is easier to be removed from the second groove, and the molding difficulty of the second groove is reduced.

[0009] In some embodiments, the second groove further includes a first groove bottom surface, the first groove bottom surface 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, the width of the first notch is L2, and the following is satisfied: L1<L2. In this way, the second groove is a structure with a wide top and a narrow bottom, which facilitates the removal of a molding tool used to mold the second groove from the second groove, and facilitates the molding of the second groove.

[0010] In some embodiments, 0.05mm≤L1≤0.3mm; L1≥0.05mm, so that the groove bottom surface of the second groove has sufficient width, which reduces the difficulty of forming the second groove on the one hand, and reduces the risk of insufficient strength of the residual part of the second groove due to stress concentration caused by the small width of the groove bottom surface of the second groove on the other hand. L1≤0.3mm, so that the groove bottom surface of the second groove is not too wide, reducing the amount of extrusion when forming the second groove, which is conducive to improving the flatness of the predetermined pressure relief area.

[0011] In some embodiments, 0.4 mm ≤ L2 ≤ 1.2 mm. L2 ≥ 0.4 mm, so that the first notch of the second groove has a sufficient width, reducing the difficulty of forming the second groove, and enhancing the auxiliary turning effect of the second groove on the predetermined pressure relief area; L2 ≤ 1.2 mm, so that the first notch of the second groove is not too wide, reducing the amount of extrusion when forming the second groove, which is conducive to improving the flatness of the surface of the predetermined pressure relief area.

[0012] 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: D1<D2. The strength of the area where the first groove is set in the pressure relief component is smaller than the strength of the area where the second groove is set in the pressure relief component, so that the pressure relief component can be preferentially split along the first groove to achieve rapid opening of the predetermined pressure relief area.

[0013] 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: H2

[0014] In some embodiments, 0.3mm≤D2≤1.2mm. D2≥0.3mm, so that the residual part of the second groove has sufficient strength. In addition, since D1<D2, D2≥0.3mm, the residual thickness of the first groove does not need to be processed too small, which is conducive to reducing the processing difficulty of the first groove and improving the strength of the residual part of the first groove during normal use of the battery cell. D2≤1.2mm, so that the thickness of the residual part of the second groove is not too large, which improves the auxiliary flipping effect of the second groove on the predetermined pressure relief area.

[0015] In some embodiments, the pressure relief component is provided with a plurality of second grooves, the first groove defines a plurality of predetermined pressure relief areas, and each predetermined pressure relief area is provided corresponding to at least one second groove. When the battery cell is in thermal runaway, the plurality of predetermined pressure relief areas can be opened, and when the total pressure relief area of ​​the pressure relief component is constant, the opening rate of the predetermined pressure relief areas can be increased, and pressure relief can be achieved more quickly.

[0016] ​In some embodiments, there are two predetermined pressure relief areas and two second grooves; the first groove includes a first groove section, and along 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 located on both sides of the first groove section, and the side surface of the first groove is closer to the first groove section than the side surface of the second groove. The first groove section of the first groove is located between the two predetermined pressure relief areas, and after the pressure relief component is split along the first groove section, the two predetermined pressure relief areas can be opened in a split manner to relieve pressure when the battery cell is depressurized, so that the two predetermined pressure relief areas can be opened quickly, which is conducive to improving the pressure relief rate of the battery cell.

[0017] 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 reducing the risk of the first groove and the second groove being connected to each other during the processing.

[0018] In some embodiments, the second groove is spaced apart from the first groove along the width direction of the second groove. In this way, the projection of the second groove along the thickness direction of the first wall portion and the projection of the first groove along the thickness direction of the first wall portion can be achieved without overlapping, which can reduce the mutual influence between the first groove and the second groove during the processing, and can reduce the residual stress between the area where the first groove is set and the area where the second groove is set, and can reduce the risk of cracks caused by the cracking of the pressure relief component along the first groove spreading to the second groove, thereby causing the pressure relief component to crack along the second groove.

[0019] In some embodiments, along the thickness direction of the first wall portion, two ends of the projection of the second groove along 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.

[0020] 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 respectively located on both sides of the pressure relief component in the thickness direction, so that the first groove and the second groove can be processed on both sides of the pressure relief component, which is conducive to reducing the mutual influence of the first groove and the second groove during the processing.

[0021] 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, so that the projections of the first groove and the second groove in the width direction of the second groove have overlapping areas, thereby, on the one hand, improving the absorption effect of the second groove on the residual material extruded during the molding of the first groove, reducing the risk of the extruded residual material of the first groove diffusing to the surface close to the shell along the width direction of the second groove, and causing the surface to be uneven, and on the other hand, improving 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 forces and deformed along the width direction of the second groove, 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.

[0022] 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 is conducive to achieving a larger overlap area between the projections of the second groove and the first groove in the width direction of the second groove, further improving the absorption effect of the second groove on the excess material extruded from the first groove during molding, and further improving 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 forces and deformed along the width direction of the second groove.

[0023] 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: D1<H2. Such a structure is conducive to achieving more overlapping areas between the projections of the second groove and the first groove in the width direction of the second groove, further improving the absorption effect of the second groove on the residual material extruded by the first groove during molding, and further improving 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 forces and deformed along the width direction of the second groove.

[0024] In some embodiments, the first groove includes a multi-level groove arranged in sequence along the direction from the second surface to the first surface, and along the thickness direction of the first wall portion, in two adjacent level grooves, the first level groove away from the second surface is arranged on the groove bottom surface of the first level groove close to the second surface; wherein, the first level groove arranged on the second surface in the multi-level groove is the first level groove, and along the width direction of the second groove, the projection of the second groove and the first level groove at least partially overlap. By arranging the first groove in the thickness direction of the first wall portion, the first level grooves can be processed 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 level groove, reducing the forming force on 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 projections of the first-stage 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 other stages in the first groove except the first-stage groove, thereby, on the one hand, improving the absorption effect of the second groove on the excess material squeezed out of the first groove when the multi-stage groove is formed, and on the other hand, further improving 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.

[0025] 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-stage groove. In this way, the projection of the second groove in the width direction can cover more parts of the first-stage groove, thereby, on the one hand, further improving the absorption effect of the second groove on the excess material squeezed out of the first groove when the multi-stage groove is formed, and on the other hand, further improving 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, the first groove is recessed from the first surface toward the second surface. In this way, the first groove and the second groove are arranged on the same side of the pressure relief component in the thickness direction, which makes it easier to process the first groove and the second groove on the pressure relief component, and the first groove and the second groove can be processed without turning the pressure relief component over, which is conducive to optimizing the production rhythm of the battery cell.

[0027] In some embodiments, the first groove includes a plurality of grooves arranged in sequence along the direction from the first surface to the second surface, and along the thickness direction of the first wall, in two adjacent grooves, the first groove away from the first surface is arranged at the groove bottom surface of the first groove close to the first surface; wherein, the first groove arranged on the first surface among the multi-level grooves is the first-level groove, and along the thickness direction of the first wall, the groove bottom surface of the first-level groove is closer to the first surface than the groove bottom surface of the second groove. By arranging the first groove in the thickness direction of the first wall, the grooves of each level can be processed one by one along the direction from the first surface to the second surface when forming the first groove, thereby reducing the forming depth of each level of groove, reducing the forming force on 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 the first-level groove is formed, 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.

[0028] 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-level groove is H3, satisfying: H3<H2. 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 the first-level groove is formed, 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, the first surface is the surface of the pressure relief component facing the inside of the shell. 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 turned outward and opened, the first groove side and the second groove side of the second groove are not easy 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 oxidation and corrosion of the pressure relief component in the second groove area. 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 inside of the shell, 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 oxidation and corrosion of the pressure relief component in the first groove area.

[0030] 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 is convenient for processing and forming the second groove on the outside of the battery cell, which is conducive to reducing the difficulty of forming the second groove, so as to improve 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 turned 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 is convenient for processing and forming the first groove on the outside of the battery cell, which is conducive to reducing the difficulty of forming the first groove, so as to improve the production efficiency of the battery cell.

[0031] In some embodiments, 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 predetermined pressure relief area. The first groove of this structure is simple in structure, and the stress at the position where the first groove section and the second groove section are connected is more concentrated and weaker, so that when the battery cell is thermally runaway, the pressure relief component can be quickly split from the first groove section and the second groove section after the position where the first groove section and the second groove section are connected is split, so that the predetermined pressure relief area is opened more quickly and the pressure is released in time.

[0032] 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 to each other, 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 arranged at intervals, and 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 such a structure makes the intersection position of the first groove section and the second groove section and the connection position of the first groove section and the third groove section weaker, and is easier to crack and open the predetermined pressure relief area for pressure relief, and can further increase the opening 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.

[0033] In some embodiments, the connection position of the second groove section and the first groove section deviates from the two ends of the second groove section, and the connection position of the third groove section and the first groove section deviates from the two ends of the third groove section, so that predetermined pressure relief areas are formed on both sides of the first groove section. The first groove section of the first groove is 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 be opened in a split manner to relieve pressure when the battery cell is depressurized, so that the two predetermined pressure relief areas can be opened quickly, which is conducive to improving the pressure relief rate of the battery cell.

[0034] In some embodiments, the first slot segment extends along a straight line or an arc track; and / or, the second slot segment extends along a straight line or an arc track; and / or, the third slot segment extends along a straight line or an arc track. If the first slot segment extends along a straight line track, 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 arc track, the first slot segment is an arc-shaped slot, and the pressure relief component is more likely to split along the first slot segment when the battery cell is depressurized, so that the predetermined pressure relief area is opened more quickly. If the second slot segment extends along a straight line track, the second slot segment is a straight line slot, which can reduce the difficulty of forming the second slot segment. If the second slot segment extends along an arc track, the second slot segment is an arc-shaped slot, and the pressure relief component is more likely to split along the second slot segment when the battery cell is depressurized, so that the predetermined pressure relief area is opened more quickly. If the third slot segment extends along a straight line track, 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.

[0035] 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.

[0036] In some embodiments, the second groove extends along a straight track. The second groove is a straight groove with a simple structure and is easy to process and shape.

[0037] 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 to form an integrated pressure relief structure, which has higher reliability, saves the installation process of the pressure relief component, and has better economy.

[0038] In some embodiments, the pressure relief component is separately arranged from the first wall portion, and the pressure relief component is installed 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, with low production difficulty and high efficiency.

[0039] In some embodiments, the first groove is stamped and formed on the pressure relief component. In this way, the first groove is formed in a simple manner, which is conducive to reducing the production cost of the battery cell.

[0040] 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.

[0041] 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 is depressurized. In addition, during the 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 absorb the deformation energy of the battery cell when the battery cell expands and deforms along the width direction of the first wall portion, reducing the impact of the expansion of the battery cell along the width direction of the first wall portion on the pressure relief component.

[0042] In some embodiments, the housing includes a shell and an end cover; an opening is formed at least at one end of the shell; the end cover corresponds to the opening one by one, and the end cover closes the opening; wherein at least one end cover is a first wall portion. This allows at least one end cover to have a pressure relief function, and the difficulty of forming the first groove and the second groove on the end cover or the difficulty of installing the pressure relief component is lower.

[0043] In some embodiments, the housing includes a shell and an end cover; an opening is formed at least at one end of the shell; the end cover corresponds to the opening one by one, and the end cover closes the opening; wherein at least one wall portion in the shell is a first wall portion. The shell has a pressure relief function, and when the battery cell is depressurized, the discharge discharged from the inside of the battery cell is not likely to affect the external components outside the end cover, thereby reducing the risk of external components being damaged by the discharge.

[0044] In some embodiments, the shell has an opening at only one end, and the wall portion of the shell opposite to the end cap is the first wall portion. The shell has an opening at one end, which makes the structure of the entire battery cell simpler. The first wall portion is the wall portion of the shell opposite to the end cap, which can achieve directional pressure relief from the bottom of the shell.

[0045] In some embodiments, openings are formed at both opposite ends of the shell, and at least one wall portion in the shell is a first wall portion. The shell is a structure with openings formed at both opposite ends, and the electrode assembly can be assembled into the shell through any opening, which can reduce the difficulty of assembling the battery cell and improve the assembly quality of the battery cell. The shell of this structure can make the length (openings are formed at both ends of the shell in the length direction) larger, which is conducive to increasing the capacity of the battery cell.

[0046] In some embodiments, the material of the pressure relief component includes steel. Steel has the characteristic of high strength, and the pressure relief component made of steel has better strength. Under the condition of a certain bursting pressure of the battery cell, the pressure relief component can be made thinner to reduce the volume of the pressure relief component.

[0047] In some embodiments, the steel material is carbon steel or stainless steel.

[0048] In some embodiments, the pressure relief component is made of aluminum alloy, which has the characteristics of light weight and good ductility, and it is easier to process the first groove and the second groove on the pressure relief component.

[0049] 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 single elements ≤ 0.03%. This aluminum alloy has lower hardness, better forming ability, reduces the difficulty of processing the first groove and the second groove, is conducive to improving the processing accuracy of the first groove and the second groove, and improves the pressure relief consistency of the pressure relief component.

[0050] In some embodiments, the aluminum alloy includes the following components in percentage by mass: 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 elements in total ≤ 0.15%. The pressure relief component made of such an aluminum alloy has higher hardness, greater strength, and good anti-destruction ability.

[0051] In a second aspect, an embodiment of the present application provides a battery, comprising a battery cell provided in any one of the embodiments of the first aspect.

[0052] In a third aspect, an embodiment of the present application provides an electrical device, comprising a battery cell provided by any one of the embodiments of the first aspect, wherein the battery cell is used to provide electrical energy to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. 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 related drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0055] Figure 2 An exploded view of a battery provided for some embodiments of the present application;

[0056] Figure 3 An exploded view of a battery cell provided for some embodiments of the present application;

[0057] Figure 4 for Figure 3 An assembly diagram of a battery cell is shown;

[0058] Figure 5 for Figure 4 A partial view of the housing is shown;

[0059] Figure 6 for Figure 5 AA section view of the housing shown;

[0060] Figure 7 for Figure 6 A partial enlarged view of point B in the middle;

[0061] Figure 8 for Figure 7 A partial enlarged view of point C in the middle;

[0062] Fig. 9 Assembly diagrams of battery cells provided for other embodiments of the present application;

[0063] Fig.10 for Fig. 9 A partial view of the housing is shown;

[0064] Fig.11 for Fig.10 DD section view of the housing shown;

[0065] Fig.12 for Fig.11 A partial enlarged view of point E in the middle;

[0066] Fig.13 A partial cross-sectional view of a housing provided for some embodiments of the present application;

[0067] Fig.14 for Fig.13 A partial enlarged view of point F in the middle;

[0068] Fig.15 A partial view of a housing provided for some other embodiments of the present application;

[0069] Fig.16 for Fig.15 GG section view of the housing shown;

[0070] Fig.17 A partial view of a housing provided for some further embodiments of the present application;

[0071] Fig.18 for Fig.17 HH section view of the housing shown;

[0072] Fig.19 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;

[0073] Fig. 20 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;

[0074] Fig.21 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;

[0075] Fig. 22 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 installed on the first wall portion) provided in some embodiments of the present application;

[0076] Fig.23 An exploded view of a battery cell provided for some other embodiments of the present application.

[0077] Icons: 1-housing; 11-housing; 12-end cover; 13-first wall; 131-pressure relief hole; 14-second wall; 15-third wall; 2-electrode assembly; 21-ear; 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

[0078] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0079] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. 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 and secondary relationship.

[0080] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0081] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0082] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0083] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0084] The term "plurality" used in the present application refers to two or more (including two).

[0085] 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.

[0086] 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, and the like.

[0087] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to reduce the risk of short circuit between the positive and negative electrodes, while allowing active ions to pass through.

[0088] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet 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.

[0089] 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 disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0090] 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 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.).

[0091] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries can also be used. These positive electrode active materials can 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 / 3O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and its modified compounds, etc.

[0092] In some embodiments, the positive electrode may be a foamed metal. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, or a carbon foam. When the foamed metal is used as the positive electrode, the positive electrode active material may not be provided on the surface of the foamed metal, but of course, the positive electrode active material may also be provided. As an example, a lithium source material, potassium metal or sodium metal may also be filled or / and deposited in the foamed metal, and the lithium source material is lithium metal and / or a lithium-rich material.

[0093] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0094] As an example, the negative electrode current collector may be a metal foil, a foamed metal or a composite current collector. For example, as the metal foil, aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc., treated with silver surface, may be used. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, etc. The composite current collector may include a polymer material base 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 and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0095] 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.

[0096] 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 disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0097] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells 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.

[0098] 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.

[0099] In some embodiments, the separator is a separator membrane, which can be any known porous separator membrane with good chemical stability and mechanical stability.

[0100] As an example, the material of the separator may include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or may be attached to the surface of the positive and negative electrodes.

[0101] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0102] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The electrolyte can be liquid, gel or solid. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0103] 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 dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0104] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl 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.

[0105] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0106] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0107] 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, and the like.

[0108] 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.

[0109] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0110] 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.

[0111] In some embodiments, the electrode assembly is a laminate structure.

[0112] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

[0113] 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.

[0114] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded sections that are stacked.

[0115] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0116] As an example, the separator may be disposed continuously, and may be disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0117] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0118] In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0119] In some embodiments, the 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 (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0120] 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. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery.

[0121] 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.

[0122] 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.

[0123] 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 accommodated in the case.

[0124] 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.

[0125] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0126] The development of battery technology must take into account many 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.

[0127] In order to improve the reliability of the battery cell, a pressure relief component can generally be provided in the battery cell. The pressure relief component can be a part of the outer shell of the battery cell or a component installed on the outer shell. When the battery cell thermally runs away, the pressure inside the battery cell can be released through the pressure relief component.

[0128] 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.

[0129] In order to make the predetermined pressure relief area of ​​the pressure relief component easier to open, a flip groove can be set on the pressure relief component, and the flip groove can be used to help the pressure relief area of ​​the pressure relief component open, thereby reducing the difficulty of opening the pressure relief area. For the flip notch, in the width direction of the flip groove, the flip groove has two opposite groove sides, and 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, so that the extruded excess material accumulates in the predetermined pressure relief area, forming a pile 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 set on the surface of the pressure relief component facing the inside of the shell, it may cause a pile bulge to form on the inner surface of the predetermined pressure relief area, increasing the risk of the components inside the shell applying an extrusion force to the pile bulge, causing the predetermined pressure relief area to open prematurely. For another example, a flip groove is set on the surface of the pressure relief component facing the outside of the shell, which 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.

[0130] Based on the above considerations, in order to alleviate the problem that the predetermined pressure relief zone is opened in advance and affects the service life of the battery cell, an embodiment of the present application provides a battery cell, the battery cell includes a shell and a pressure relief component, the shell includes a first wall portion, and the pressure relief component is arranged 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 be able to split along at least a portion of the first groove when the battery cell is depressurized, along the thickness direction of the first wall portion, the pressure relief component has a first surface and a second surface opposite to each other, the second groove is recessed from the first surface to the direction close to the second surface, and the second groove is configured to guide at least a portion of the predetermined pressure relief zone to flip to open at least a portion of the predetermined pressure relief zone. Along the width direction of the second groove, the second groove includes a first groove side surface and a second groove side surface that are arranged oppositely 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 and the first surface The angle formed by 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°.

[0131] 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 diffused to the predetermined pressure relief area, reduce the height of the pile bulge formed by the excess material squeezed out from the area where the second groove of the pressure relief component is set and accumulate 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.

[0132] The battery cells described in the embodiments of the present application are suitable for batteries and electrical equipment using the battery cells.

[0133] Electrical equipment may be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, electric tools, and the like. Vehicles may be fuel vehicles, gas vehicles, or new energy vehicles, and new energy vehicles may be pure electric vehicles, hybrid vehicles, or extended-range vehicles, and the like; spacecraft include airplanes, rockets, space shuttles, and spacecraft, and the like; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like; 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, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical equipment.

[0134] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0135] Please refer to Figure 1 , Figure 1 The schematic diagram of the structure of the vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 is provided with a battery 100 inside, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000, for example, the battery 100 can be used as an operating power source of the vehicle 1000.

[0136] The vehicle 1000 may further include a controller 200 and a motor 300 , wherein 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 starting, navigating, and driving the vehicle 1000 .

[0137] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0138] Please refer to Figure 2 , Figure 2 The exploded view of the battery 100 provided in some embodiments of the present application. The battery 100 includes a battery cell 10 and a box body 20, and the battery cell 10 is accommodated in the box body 20.

[0139] Among them, the box body 20 is a component for accommodating the battery cell 10. The box body 20 provides a storage space for the battery cell 10. The box body 20 can adopt a variety of structures. In some embodiments, the box body 20 may include a first part 201 and a second part 202, and the first part 201 and the second part 202 cover each other to define a storage space for accommodating the battery cell 10. The first part 201 and the second part 202 may be in a variety of shapes, such as a rectangular parallelepiped, a cylindrical shape, etc. The first part 201 may be a hollow structure with one side open, and the second part 202 may also be a hollow structure with one side open, and the open side of the second part 202 covers the open side of the first part 201, so as to form a box body 20 with a storage space. It is also possible that the first part 201 is a hollow structure with one side open, and the second part 202 is a plate-like structure, and the second part 202 covers the open side of the first part 201, so as to form a box body 20 with a storage space. The first part 201 and the second part 202 can be sealed by a sealing element, and the sealing element can be a sealing ring, a sealant, etc.

[0140] In the battery 100, there may be one or more battery cells 10. If there are more than one battery cell 10, the battery cells 10 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the battery cells 10 are both connected in series and in parallel. The battery modules may be connected in series, in parallel, or in a mixed connection to form a battery module, and then the battery modules may be connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 20. Alternatively, all the battery cells 10 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by all the battery cells 10 may be accommodated in the box 20.

[0141] Please refer to Figure 3 , Figure 3 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.

[0142] 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 .

[0143] The shell 11 is a component for accommodating the electrode assembly 2. The shell 11 may be a hollow structure with an opening formed at one end, or a hollow structure with openings formed at opposite ends. The shell 11 may be in various shapes, such as a cylindrical shape, a rectangular parallelepiped shape, etc. The shell 11 may be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0144] 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, the electrolyte and other components. The end cap 12 can be connected to the shell 11 by welding or crimping 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.

[0145] In the embodiment where the housing 11 is opened at one end, one end cap 12 may be provided. In the embodiment where the housing 11 is opened at two opposite ends, two end caps 12 may be provided, and the two end caps 12 respectively close the two openings of the housing 11, and the two end caps 12 and the housing 11 together define a receiving space.

[0146] In some embodiments, the battery cell 10 may further include an electrode terminal 3, which is disposed on the housing 1 and is used to electrically connect to the tab 21 of the electrode assembly 2 to output the electrical energy of the battery cell 10. The electrode terminal 3 may be disposed on the shell 11 of the housing 1 or on the end cover 12 of the housing 1. The electrode terminal 3 and the tab 21 may be directly connected, for example, the electrode terminal 3 and the tab 21 are directly welded. The electrode terminal 3 and the tab 21 may also be indirectly connected, for example, the electrode terminal 3 and the tab 21 are indirectly connected through a current collecting member 4. The current collecting member 4 may be a metal conductor, for example, copper, iron, aluminum, steel, aluminum alloy, etc.

[0147] As an example, Figure 3 As shown, an opening is formed at one end of the shell 11, and there is one end cap 12 in the shell 1, and one end cap 12 closes one opening of the shell 11. Two electrode terminals 3 are arranged on the end cap 12, and the two electrode terminals 3 are respectively a positive electrode terminal and a negative electrode terminal. A positive electrode ear and a negative electrode ear are formed at one end of the electrode assembly 2 facing the end cap 12, and the positive electrode terminal is connected to the positive electrode ear through a current collecting component 4, and the negative electrode terminal is connected to the negative electrode ear through another current collecting component 4.

[0148] In some embodiments, please refer to Figure 3 The battery cell 10 may further include an insulating member 5, which is a component that separates the housing 11 from the electrode assembly 2, and the insulating member 5 is used to achieve insulation isolation between the housing 11 and the electrode assembly 2. The insulating member 5 is made of insulating material, and the material of the insulating member 5 includes but is not limited to: plastic, rubber, etc.

[0149] As an example, the insulating member 5 is wrapped around the outside of the electrode assembly 2 along the circumferential direction of the opening of the shell 11. The electrode assembly 2 in the shell 1 can be one or more. If there is one electrode assembly 2, the insulating member 5 is wrapped around the electrode assembly 2; if there are multiple electrode assemblies 2, one insulating member 5 can be set corresponding to one electrode assembly 2, and each insulating member 5 is wrapped around one electrode assembly 2, or multiple electrode assemblies 2 can be used as an integral component, and the insulating member 5 is wrapped around the integral component.

[0150] Please refer to Figure 4-Figure 7 , Figure 4 for Figure 3 An assembly diagram of the battery cell 10 is shown; Figure 5 for Figure 4 A partial view of the housing 1 is shown; Figure 6 for Figure 5 AA sectional view of the housing 1 shown; Figure 7 for Figure 6A partial enlarged view of the B in the figure. The embodiment of the present application provides a battery cell 10, including a housing 1 and a pressure relief component 6, the housing 1 includes a first wall portion 13, and the pressure relief component 6 is arranged on the first wall portion 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, and the pressure relief component 6 is configured to be able to split along at least a portion of the first groove 61 when the battery cell 10 is depressurized. Along the thickness direction X of the first wall portion, the pressure relief component 6 has a first surface 64 and a second surface 65 opposite to each other, the second groove 62 is recessed from the first surface 64 to a direction close to the second surface 65, and the second groove 62 is configured to guide at least a portion of the predetermined pressure relief area 63 to flip, so as to open 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 arranged opposite to each other 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.

[0151] The housing 1 may include a plurality of walls, which together define a receiving space inside the housing 1 to accommodate the battery cell 10, electrolyte and other components, which may be current collecting components 4, insulating components 5 and other components. Among the plurality of walls of the housing 1, one wall may be the first wall 13, or a plurality of walls may be the first wall 13. Taking the housing 1 as a rectangular parallelepiped as an example, there are six walls in the housing 1, and one, two, three, four, five or six walls may be the first wall 13. In the housing 1, at least one end cover 12 may be the first wall 13, or at least one wall in the shell 11 may be the first wall 13.

[0152] The pressure relief component 6 is a component in the battery cell 10 for releasing the pressure inside the battery cell 10. The pressure relief component 6 is arranged on the first wall portion 13, and the pressure relief component 6 and the first wall portion 13 may be integrally formed, or the pressure relief component 6 and the first wall portion 13 may be separately arranged, and the pressure relief component 6 is installed on the first wall portion 13. If the pressure relief component 6 and the first wall portion 13 are integrally formed, so that the pressure relief component 6 is at least a part of the first wall portion 13, that is, the first wall portion 13 may be the entire pressure relief component 6, or a part of the first wall portion 13 may be the pressure relief component 6.

[0153] 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 bursting pressure of the pressure relief component 6, the pressure relief component 6 can be split along at least a portion of the first groove 61 to open the predetermined pressure relief area 63. It is understandable that when the pressure of the battery cell 10 is released, the pressure relief component 6 can be split along the entire first groove 61, or can be split 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 a variety of ways, such as stamping, milling, etc. The first groove 61 can include at least one groove segment, and the cross-section of the groove segment can be in a variety of shapes, such as rectangular, trapezoidal, etc., and the cross-section of the groove segment is perpendicular to the extension direction of the groove segment. The shape of the first groove 61 can be various, for example, the first groove 61 is a groove extending along an arc trajectory, and for another example, the first groove 61 includes a plurality of groove segments, and the plurality of groove segments can form a U-shape, an H-shape, a V-shape, a Y-shape, an X-shape, etc.

[0154] The second groove 62 is a flip groove provided on the pressure relief component 6. When the pressure relief component 6 is split along at least a portion of the first groove 61, the second groove 62 can guide at least a portion of the predetermined pressure relief area 63 to flip. That is, the second groove 62 plays a role in helping the predetermined pressure relief area 63 to flip, making it easier for the predetermined pressure relief area 63 to flip toward the outside of the battery cell 10, thereby quickly opening the predetermined pressure relief area 63. The second groove 62 can guide the entire flipping of the predetermined pressure relief area 63, or the second groove 62 can only guide the flipping of a portion of the predetermined pressure relief area 63. During the pressure relief process of the battery cell 10, the pressure relief component 6 can be split along at least a portion of the first groove 61, and generally will not be split along the second groove 62. The minimum thickness of the residual portion of the area where the first groove 61 of the pressure relief component 6 is provided can be less than the minimum thickness of the residual portion of the area where the second groove 62 of the pressure relief component 6 is provided, so that the area where the first groove 61 of the pressure relief component 6 is provided is easier to split than the area where the second groove 62 of the pressure relief component 6 is provided. The second groove 62 can be formed in various ways, such as stamping, milling, etc. The second groove 62 can have various shapes, such as the second groove 62 is a groove extending along an arc track, and the second groove 62 is a groove extending along a straight track. The cross-section of the second groove 62 can have various shapes, such as a rectangle, a trapezoid, etc.

[0155] The second groove 62 not only has the function of facilitating the flipping of the predetermined pressure relief area 63, but also has a buffering function. The second groove 62 can absorb the excess material extruded when the first groove 61 is formed, reducing the risk of the extruded excess material of the first groove 61 spreading to the surface close to the shell 1 along the width direction Z of the second groove, and improving the flatness of the surface of the shell 1 along the width direction Z of the second groove. When the shell 1 of the battery cell 10 is subjected to internal and external impact forces and deformed along the width direction Z of the second groove, the second groove 62 can also absorb the deformation energy of the shell 1, 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.

[0156] The second groove 62 and the first groove 61 may be directly connected, or the second groove 62 and the first groove 61 may not contact each other. The second groove 62 and the first groove 61 may be arranged on the same surface of the pressure relief component 6 along the thickness direction X of the first wall portion, or the second groove 62 and the first groove 61 may be arranged on two opposite 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, the second groove 62 and the first groove 61 may be arranged 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, along the thickness direction X of the first wall portion, the projection of the second groove 62 and the projection of the first groove 61 may partially overlap or may not overlap.

[0157] 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 split 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 corresponding to one second groove 62. Alternatively, each predetermined pressure relief area 63 may be provided corresponding to multiple second grooves 62. The predetermined pressure relief area 63 may be triangular, rectangular, trapezoidal, semicircular, etc. Figure 5 In the illustrated embodiment, there are two predetermined pressure relief areas 63. Figure 5 The two shaded parts shown in FIG. 6 are two predetermined pressure relief areas 63 .

[0158] One of the first surface 64 and the second surface 65 may be the outer surface of the pressure relief component 6, and the other may 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 may be planes. The first surface 64 and the second surface 65 may 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 may be arranged on the first surface 64 or on the second surface 65. As an example, in Figure 7 In the illustrated embodiment, 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 disposed on the second surface 65 .

[0159] 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 smoothly transition 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 smoothly transition through an arc surface. As an example, in Figure 7 In the illustrated embodiment, the first surface 64 , the first groove side surface 621 , and the second groove side surface 622 are all planar.

[0160] 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°.

[0161] When measuring the angle a and the angle b, the pressure relief component 6 can be cut along the direction Y perpendicular to the extension of the second groove, and then the angle between the first groove side surface 621 and the first surface 64 and the angle between the second groove side surface 622 and the first surface 64 can be measured on the cut surface by a measuring tool. Alternatively, the first groove side surface 621, the second groove side surface 622 and the first surface 64 can be scanned and imaged on the cut surface by a CT scanning device, and then the angle between the first groove side surface 621 and the first surface 64 and the angle between the second groove side surface 622 and the first surface 64 can be measured.

[0162] As an example, in Figure 4-Figure 7 In the illustrated embodiment, the thickness direction X of the first wall is parallel to the first direction, the wall of the housing 11 opposite to the end cover 12 serves as the pressure relief component 6, the first groove 61 and the second groove 62 are respectively arranged on two opposite surfaces of the first wall in the thickness direction X, the first groove 61 is H-shaped, the second groove 62 extends along a straight track, the extension direction Y of the second groove is parallel to the second direction, the width direction Z of the second groove is parallel to the third direction, and the first direction, the second direction and the third direction 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.

[0163] In the embodiment of the present application, the pressure relief component 6 is provided with a first groove 61, and the first groove 61 defines at least one predetermined pressure relief area 63, so that the pressure relief component 6 can be split along at least a portion of the first groove 61 when the battery cell 10 is depressurized, so as to open the predetermined pressure relief area 63, so as to release the internal pressure of the battery cell 10. The pressure relief component 6 is also provided with a second groove 62, and the second groove 62 can guide at least a portion of the predetermined pressure relief area 63 to flip, so as to open at least a portion of the predetermined pressure relief area 63 for pressure relief. The second groove 62 plays an auxiliary role in the predetermined pressure relief area 63, making it easier to flip the predetermined pressure relief area 63, reducing the difficulty of flipping the predetermined pressure relief area 63, and enabling the predetermined pressure relief area 63 to be opened 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 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.

[0164] In some embodiments, 90°≤a≤150°.

[0165] In this embodiment, a can be any point value among 90°, 100°, 110°, 120°, 130°, 135°, 140°, 150°, etc., or a range value between any two of them.

[0166] 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.

[0167] In some embodiments, 90°<b≤170°.

[0168] In this embodiment, b can be 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.

[0169] 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.

[0170] In some embodiments, please refer to Figure 8 , Figure 8 for Figure 7 The second groove 62 further includes a first groove bottom surface 625, the first groove bottom surface 625 connects the first groove side surface 621 and the second groove side surface 622, and 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, which satisfies: L1<L2.

[0171] 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 position between the first groove bottom surface 625 and the first groove side surface 621 can form a rounded corner, and the connection position between the first groove bottom surface 625 and the second groove side surface 622 can form a rounded corner.

[0172] As an example, the width of the second groove 62 gradually decreases in the direction from the first groove opening 626 to the first groove bottom surface 625, the groove bottom surface of the second groove 62 (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, and 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.

[0173] 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.

[0174] In some embodiments, 0.05 mm ≤ L1 ≤ 0.3 mm;

[0175] 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.

[0176] In this embodiment, L1≥0.05mm, so that the groove bottom surface of the second groove 62 has a sufficient width, which reduces the difficulty of forming the second groove 62 on the one hand, and reduces the risk of insufficient strength of the residual part of the second groove 62 due to stress concentration caused by too small width of the groove bottom surface of the second groove 62 on the other hand. L1≤0.3mm, so that the groove bottom surface of the second groove 62 is not too wide, reducing the amount of extrusion when forming the second groove 62, which is conducive to improving the flatness of the predetermined pressure relief area 63.

[0177] In some embodiments, 0.4 mm ≤ L2 ≤ 1.2 mm.

[0178] L2 can be 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.

[0179] In this embodiment, L2≥0.4mm, so that the first notch 626 of the second groove 62 has a sufficient width, which reduces the difficulty of forming the second groove 62 and enhances 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.

[0180] In some embodiments, please refer to Figure 7 and Figure 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.

[0181] The minimum residual thickness of the first groove 61 is the minimum thickness of the residual part after the pressure relief component 6 is provided with the first groove 61, and the residual part may be the groove bottom wall of the first groove 61. The thickness of the groove bottom wall of the first groove 61 may be uniform or uneven. If the thickness of the groove bottom wall of the first groove 61 is uneven, the thickness of the thinnest position of the groove bottom wall of the first groove 61 is the minimum residual thickness of the first groove 61. In the embodiment where the first groove 61 includes a plurality of groove sections, the minimum residual thickness of all groove sections may be equal, and the minimum residual thickness of any groove section is the minimum residual thickness of the first groove 61; if the minimum residual thickness of at least two groove sections is not equal, the minimum residual thickness of the groove section with the smallest minimum residual thickness is the minimum residual thickness of the first groove 61. Among them, the minimum residual thickness of a groove section is the minimum thickness of the residual part after the pressure relief component 6 is provided with the groove section, and the residual part may be the groove bottom wall of the groove section.

[0182] The minimum residual thickness of the second groove 62 is the minimum thickness of the residual portion of the pressure relief component 6 after the second groove 62 is provided, and the residual portion may be the groove bottom wall of the second groove 62. The thickness of the groove bottom wall of the second groove 62 may be uniform or non-uniform. If the thickness of the groove bottom wall of the second groove 62 is non-uniform, the thickness of the thinnest position of the groove bottom wall of the second groove 62 is the minimum residual thickness of the second groove 62.

[0183] 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.

[0184] 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

[0185] 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.

[0186] 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 .

[0187] ​In this embodiment, H2

[0188] 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.

[0189] 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.

[0190] It is understandable that if the pressure relief component 6 and the first wall portion 13 are formed integrally, the first wall portion 13 can serve as the pressure relief component 6 , and the thickness of the pressure relief component 6 is the thickness of the first wall portion 13 .

[0191] 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 beneficial to improving the timeliness of the pressure relief of the battery cell 10.

[0192] In some embodiments, 0.4 mm ≤ H1 ≤ 2 mm, 0.8 mm ≤ D ≤ 2.5 mm.

[0193] 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 any range value between any two of them.

[0194] ​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.

[0195] In some embodiments, 0.3 mm ≤ D2 ≤ 1.2 mm.

[0196] L2 can be 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.

[0197] In this embodiment, D2≥0.3mm, so that the remaining portion of the second groove 62 has sufficient strength. In addition, since D1<D2, D2≥0.3mm, the remaining thickness of the first groove 61 does not need to be processed too small, which is conducive to reducing the processing difficulty of the first groove 61 and improving the strength of the remaining portion of the first groove 61 during the normal use of the battery cell 10. D2≤1.2mm, so that the thickness of the remaining portion of the second groove 62 is not too large, and the auxiliary flipping effect of the second groove 62 on the predetermined pressure relief area 63 is improved.

[0198] In some embodiments, please refer to Figure 5 The pressure relief component 6 is provided with a plurality of second grooves 62 , and 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 .

[0199] 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 arranged corresponding to at least one second groove 62, that is, each predetermined pressure relief area 63 may be arranged corresponding to one second groove 62, or may be arranged corresponding to a plurality of second grooves 62.

[0200] 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, thereby achieving faster pressure relief.

[0201] 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, and along the width direction Z of the second groove, the first groove section 611 is located between the two second grooves 62, and the two predetermined pressure relief areas 63 are respectively located on both sides 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.

[0202] It can be understood that the predetermined pressure relief area 63 corresponds to the second groove 62 one by one.

[0203] 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 .

[0204] The areas of the two predetermined pressure relief areas 63 may be equal or unequal. 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 and the first groove section 611 may be parallel, or the extension line of the second groove 62 may intersect the extension line of the first groove section 611.

[0205] As an example, in Figure 5 In the illustrated embodiment, multiple groove sections of the first groove 61 form an H-shaped structure, the first groove section 611 and the second groove 62 both extend along a straight line trajectory, the first groove section 611 is parallel to the second groove 62, the two second grooves 62 are equidistant from the first groove section 611, and the two predetermined pressure relief areas 63 are symmetrically arranged on both sides of the first groove section 611, so that the areas of the two predetermined pressure relief areas 63 are equal.

[0206] In the present 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.

[0207] In some embodiments, please refer to Figure 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 .

[0208] 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 .

[0209] 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 .

[0210] 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.

[0211] 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.

[0212] In some embodiments, along the width direction Z of the second groove, the second groove 62 is spaced apart from the first groove 61 .

[0213] The second groove 62 and the first groove 61 are spaced apart in the width direction Z of the second groove, that is, the projection of the second groove 62 in the thickness direction X of the first wall portion and the projection of the first groove 61 in the thickness direction X of the first wall portion are spaced apart 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 two opposite sides of the pressure relief component 6 in the thickness direction X of the first wall portion. It can be understood that the projection of the second groove 62 in the thickness direction X of the first wall portion and the projection of the first groove 61 in the thickness direction X of the first wall portion are spaced apart in the width direction Z of the second groove.

[0214] As an example, in Figure 6In the illustrated embodiment, 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 arranged opposite to each other. The first wall portion 13 connects the first wall portion 13 and the third wall portion 15. The first wall portion 13 is a 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.

[0215] In this embodiment, the second groove 62 and the first groove 61 are spaced apart in 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, and 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.

[0216] In the above embodiment, along the width direction Z of the second groove, the second groove 62 is spaced apart from the first groove 61, so that the projection of the first groove 61 along the thickness direction X of the first wall portion is not located in the predetermined pressure relief area 63. In other embodiments, the projection of the first groove 61 along the thickness direction X of the first wall portion may be partially or entirely located in the predetermined pressure relief area 63.

[0217] In some embodiments, please refer to Figure 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 out of two ends of the projection of the first groove 61 .

[0218] 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 out of 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 extension direction Y of the second groove. As an example, along the extension direction Y of the second groove, 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 extension direction Y of the second groove).

[0219] In this embodiment, along the thickness direction X of the first wall portion, the two ends of the projection of the second groove 62 along the extension direction respectively extend out of the two ends of the projection of the first groove 61, so that the second groove 62 is longer, and the auxiliary flipping effect of the second groove 62 on the predetermined pressure relief area 63 is enhanced. In addition, this structure can also improve the separation effect of the second groove 62 on 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) and the first groove 61, improve the absorption effect of the second groove 62 on the excess material extruded during the molding of the first groove 61, improve the flatness of the surface of the battery cell 10 in the width direction Z of the second groove, and can improve the blocking 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 reduce the influence of the expansion of the battery cell 10 on the pressure relief component 6.

[0220] 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 .

[0221] In some embodiments, please refer to Figure 7 The first groove 61 is recessed from the second surface 65 toward the first surface 64 .

[0222] It can be understood that the first groove 61 is disposed on the second surface 65 , and the second groove 62 is disposed on the first surface 64 .

[0223] 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.

[0224] 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 as to facilitate the processing of the first groove 61 and the second groove 62 on both sides of the pressure relief component 6, which is beneficial to reduce the mutual influence of the first groove 61 and the second groove 62 during the processing.

[0225] In some embodiments, please refer to Figure 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.

[0226] 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 corresponding to the second groove 62 on the second surface 65, so that the second groove 62 does not penetrate the pressure relief component 6 along the thickness direction X of the first wall, and a second protrusion may be provided at a position corresponding to the first groove 61 on the first surface 64, so that the first groove 61 does not penetrate the pressure relief component 6 along the thickness direction X of the first wall.

[0227] 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 in the width direction Z of the second groove at least partially overlap.

[0228] 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.

[0229] 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 an overlapping area, thereby, on the one hand, being able to improve the absorption effect of the second groove 62 on the residual material extruded from the first groove 61 during molding, and reducing the risk of the extruded residual material of the first groove 61 diffusing to the surface close to the outer shell 1 along the width direction Z of the second groove, thereby causing the surface to be uneven; on the other hand, being able to 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 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.

[0230] 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.

[0231] 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 .

[0232] 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 that the projections of the second groove 62 and the first groove 61 in the width direction Z of the second groove have more overlapping areas, further improving the absorption effect of the second groove 62 on the excess 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.

[0233] 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.

[0234] As an example, the first surface 64 is parallel to the second surface 65, the notch (first notch 626) of the second groove 62 is located on the first surface 64, and 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 the residual portion is the minimum residual thickness of the first groove 61. The first surface 64 is a measurement reference surface for the maximum groove depth of the second groove 62 and the minimum residual thickness of the first groove 61.

[0235] In the present embodiment, D1<H2. 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.

[0236] In some embodiments, please refer to Figure 9-12 , Fig. 9 Assembly diagrams of battery cells 10 provided for other embodiments of the present application; Fig.10 for Fig. 9 A partial view of the housing 1 is shown; Fig.11 for Fig.10 DD sectional view of the housing 1 shown; Fig.12 for Fig.11The first groove 61 includes a multi-stage groove arranged in sequence 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 first-stage groove far from the second surface 65 is arranged on the groove bottom surface of the first-stage groove close to the second surface 65. Among them, the first-stage groove arranged on the second surface 65 in the multi-stage groove is the first-stage groove 615. Along the width direction Z of the second groove, the projection of the second groove 62 and the first-stage groove 615 at least partially overlap.

[0237] The first groove 61 can be a two-stage groove, a three-stage groove, a four-stage groove, a five-stage groove, etc. It can be understood that the first groove 61 is a stepped groove. Along the direction from the second surface 65 to the first surface 64, the groove width of each stage of the groove gradually decreases. Fig.12 As shown, taking the first groove 61 as a two-level groove as an example, the two-level grooves are respectively a first-level groove 615 and a second-level groove. During processing, a first-level groove 615 with a larger width can be processed on the second surface 65 first, and then a second-level groove with a smaller width can be processed on the bottom surface of the first-level groove 615.

[0238] The first-level groove 615 is a first-level groove disposed on the second surface 65 in the first groove 61. In the embodiment where the first groove 61 includes a plurality of groove sections, it can be understood that each groove section is a multi-level groove, and the first-level grooves of all groove sections disposed on the second surface 65 constitute the first-level groove 615. In the multi-level grooves of the first groove 61, the groove bottom surface of the first-level groove farthest from the second surface 65 is the groove bottom surface 614 of the first groove, the minimum residual thickness of the first-level 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-level groove farthest from the second surface 65 and the second surface 65 is equal to the maximum groove depth of the first groove 61.

[0239] 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 corresponding to the second groove 62 on the second surface 65, so that the second groove 62 does not penetrate the pressure relief component 6 along the thickness direction X of the first wall, and a second protrusion may be provided at a position corresponding to the first-stage groove 615 on the first surface 64, so that the first groove 61 does not penetrate the pressure relief component 6 along the thickness direction X of the first wall.

[0240] 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 in the width direction Z of the second groove at least partially overlap.

[0241] In this embodiment, by arranging the first groove 61 as a multi-stage groove along the thickness direction X of the first wall, the grooves of each stage can be processed one by one along the direction from the second surface 65 to the first surface 64 when forming the first groove 61, thereby reducing the forming depth of each stage of the groove, reducing the forming force on the pressure relief component 6 when forming the first groove 61, and reducing the risk of the pressure relief component 6 being damaged when forming the first groove 61. Since the projection 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 overlap at least partially, the projection of the second groove 62 in the width direction can cover the grooves of the first groove 61 except the first stage groove 615, so that on the one hand, the absorption effect of the second groove 62 on the residual material squeezed out of the first groove 61 when the multi-stage groove is formed can be improved, and on the other hand, 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 can be further improved, thereby reducing 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.

[0242] In some embodiments, along the thickness direction X of the first wall portion, the groove bottom surface (the 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 .

[0243] 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 .

[0244] The bottom surface of the second groove 62 (the first groove bottom surface 625) can be a plane or an arc surface; the bottom surface of the first-stage groove 615 can be a plane or an arc surface. Fig.12 In the illustrated embodiment, the groove bottom surface of the first-stage groove 615 and the groove bottom surface (first groove bottom surface 625 ) of the second groove 62 are both planes and are parallel to the first surface 64 and the second surface 65 .

[0245] 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, and on the other hand, 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 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.

[0246] 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 .

[0247] In some embodiments, please refer to Fig.13 and Fig.14 , Fig.13 A partial cross-sectional view of a housing 1 provided in some embodiments of the present application; Fig.14 for Fig.13 The first groove 61 is recessed from the first surface 64 toward the second surface 65 .

[0248] It can be understood that the first groove 61 and the second groove 62 are both disposed on the first surface 64 .

[0249] 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.

[0250] In some embodiments, please refer to Fig.14 The first groove 61 includes a plurality of grooves sequentially arranged along the 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 first groove far from the first surface 64 is arranged at the groove bottom surface of the first groove close to the first surface 64. Among them, the first groove arranged on the first surface 64 in the plurality of grooves 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.

[0251] The first-level groove 615 is a first-level groove disposed on the first surface 64 in the first groove 61. Among the multi-level grooves of the first groove 61, the groove bottom surface of the first-level groove farthest from the first surface 64 is the groove bottom surface 614 of the first groove, the minimum residual thickness of the first-level groove farthest from the first surface 64 is the minimum residual thickness of the first groove 61, and the maximum distance between the groove bottom surface of the first-level 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, and the minimum distance between the groove bottom surface of the first-level groove farthest from the first surface 64 and the second surface 65 is equal to the minimum residual thickness of the first groove 61.

[0252] 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 .

[0253] The bottom surface of the second groove 62 can be a plane or a curved surface; the bottom surface of the first-stage groove 615 can be a plane or a curved surface. Fig.14 In the illustrated embodiment, the bottom surface of the first-stage groove 615 and the bottom surface of the second groove 62 are both planes and are parallel to the first surface 64 and the second surface 65 .

[0254] In this embodiment, by arranging the first groove 61 with multiple grooves along the thickness direction X of the first wall, when forming the first groove 61, each groove can be processed one by one along the direction from the first surface 64 to the second surface 65, thereby reducing the forming depth of each groove, reducing the forming force to which the pressure relief component 6 is subjected when forming the first groove 61, and reducing the risk of the pressure relief component 6 being damaged when forming the first groove 61. Since the bottom surface of the first 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 groove 615 of the first groove 61, so that the second groove 62 has a deeper depth, so that the second groove 62 can have a good absorption effect on the excess material squeezed out when forming the first groove 615, and the second groove 62 can have a good absorption effect on the deformation energy of the battery cell 10 when the battery cell 10 is subjected to internal and external impact forces and deformed.

[0255] In some embodiments, please refer 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.

[0256] 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-level 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-level groove 615. The maximum groove depth of the second groove 62 is greater than the maximum groove depth of the first-level groove 615, so that the groove bottom surface of the first-level 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).

[0257] In this embodiment, H3<H2, so that the second groove 62 has a deeper depth, so that the second groove 62 can have a good absorption effect on the residual material squeezed out when the first-level groove 615 is formed, and the second groove 62 can have a good absorption effect on the deformation energy of the battery cell 10 when the battery cell 10 is subjected to internal and external impact forces and deformed.

[0258] In some embodiments, please refer to Figure 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 .

[0259] 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 .

[0260] In this embodiment, the first surface 64 is the surface of the pressure relief component 6 facing the inside 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 process of the predetermined pressure relief area 63 being turned outward and opened, the first groove side 621 and the second groove side 622 of the second groove 62 are not easy to abut against each other, which is conducive to increasing 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 corrosion of the pressure relief component 6 in the second groove 62 area. In addition, in the case where 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 inside 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 corrosion of the pressure relief component 6 in the first groove 61 area.

[0261] In other embodiments, the first surface 64 is a surface of the pressure relief component 6 facing the outside of the housing 1 .

[0262] 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 .

[0263] In this embodiment, the first surface 64 is the surface of the pressure relief component 6 facing the outside of the housing 1, so that the second groove 62 is arranged on the outside of the pressure relief component 6, which is convenient for processing and forming the second groove 62 on the outside of the battery cell 10, which is conducive to reducing the difficulty of forming the second groove 62, so as to improve the production efficiency of the battery cell 10. Since the angle a between the first groove side 621 and the first surface 64 is smaller than the angle b 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, and the opening angle of the predetermined pressure relief area 63 is increased when the predetermined pressure relief area 63 is turned outward so that the first groove side 621 and the second groove side 622 are against each other. 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 outside of the housing 1, so that the first groove 61 is arranged on the outside of the pressure relief component 6, which is convenient for processing and forming the first groove 61 on the outside of the battery cell 10, which is conducive to reducing the difficulty of forming the first groove 61, so as to improve the production efficiency of the battery cell 10.

[0264] In some embodiments, please refer to Fig.15 and Fig.16 , Fig.15 Partial views of the housing 1 provided for other embodiments of the present application; Fig.16 for Fig.15 The GG cross-sectional view of the housing 1 is shown. The first groove 61 includes a first groove section 611 and a second groove section 612 . The first groove section 611 is connected to the second groove section 612 . The first groove section 611 and the second groove section 612 define at least one predetermined pressure relief area 63 together.

[0265] The first slot section 611 and the second slot section 612 are two slot sections in the first groove 61. The first slot section 611 and the second slot section 612 can define a predetermined pressure relief area 63 together, which can be one or more. The first slot section 611 and the second slot section 612 can be a linear slot extending along a linear trajectory, or a non-linear slot extending along a non-linear trajectory, for example, an arcuate slot extending along an arc trajectory. If the first slot section 611 and the second slot section 612 both extend along a linear trajectory, the first slot section 611 and the second slot section 612 can be arranged at an acute angle, a right angle, or an obtuse angle. The first slot section 611 and the second slot section 612 can be connected at their ends to form a V-shaped, L-shaped, or other structure, and the first slot section 611 and the second slot section 612 can define a predetermined pressure relief area 63. The first slot section 611 and the second slot section 612 can also be arranged crosswise to form an X-shaped structure, and the first slot section 611 and the second slot section 612 can define four predetermined pressure relief areas 63.

[0266] As an example, in Fig.15 and Fig.16In the illustrated embodiment, the first groove section 611 and the second groove section 612 are connected to form a V-shaped structure, and the first groove section 611 and the second groove section 612 define a predetermined pressure relief area 63. The first groove 61 is provided on the second surface 65, and the second groove 62 is provided on the first surface 64. The line connecting the end of the first groove section 611 away from the second groove section 612 and the end of the second groove section 612 away from the first groove section 611 in the second surface 65 is a first connecting line W. The first connecting line W, the second groove section 612 and the second groove section 612 are connected end to end to enclose a predetermined pressure relief area 63. Fig.15 In the figure, the triangular shaded portion is the predetermined pressure relief area 63.

[0267] 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.

[0268] In this embodiment, at least one predetermined pressure relief area 63 is 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, so that when the battery cell 10 thermally runs away, the pressure relief component 6 can be quickly split from the first groove section 611 and the second groove section 612 after the first groove section 611 and the second groove section 612 are split at the position where the first groove section 611 and the second groove section 612 are connected, so that the predetermined pressure relief area 63 is opened more quickly to release pressure in time.

[0269] In some embodiments, please refer to Fig.10 and Fig.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 is spaced apart from the second groove 62. 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.

[0270] The first slot section 611, the second slot section 612 and the third slot section 613 can jointly define a predetermined pressure relief area 63 or multiple predetermined pressure relief areas 63. The first slot section 611, the second slot section 612 and the third slot section 613 are three slot sections in the first groove 61. The first slot section 611, the second slot section 612 and the third slot section 613 can be a straight slot extending along a straight track, or a non-straight slot extending along a non-straight track, for example, an arcuate slot extending along an arc track. If the first slot section 611, the second slot section 612 and the third slot section 613 all extend along a straight track, the first slot section 611 and the second slot section 612 can be arranged at an acute angle, a right angle, or an obtuse angle, the first slot section 611 and the second slot section 612 can be arranged at an acute angle, a right angle, or an obtuse angle, the second slot section 612 and the third slot section 613 can be arranged in parallel, or the extension line of the second slot section 612 and the extension line of the third slot section 613 can intersect.

[0271] The first slot section 611 connects the second slot section 612 and the third slot section 613. The two ends of the first slot section 611 may be connected to the second slot section 612 and the third slot section 613 respectively, or at least one of the second slot section 612 and the third slot section 613 may be connected to a position deviated from the end of the first slot section 611, so that at least one of the second slot section 612 and the third slot section 613 is located between the two ends of the first slot section 611. The position where the second slot section 612 is connected to the first slot section 611 may be located at one end of the second slot section 612 or between the two ends of the second slot section 612. The position where the third slot section 613 is connected to the first slot section 611 may be located at one end of the third slot section 613 or between the two ends of the third slot section 613. The first slot section 611, the second slot section 612, and the third slot section 613 may form a U-shaped, N-shaped, H-shaped, or other structures. 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.

[0272] As an example, in Fig.10 and Fig.11In the illustrated embodiment, the first slot section 611, the second slot section 612 and the third slot section 613 form an H-shaped structure, there are two predetermined pressure relief areas 63, the first groove 61 is arranged on the second surface 65, the second groove 62 is arranged on the first surface 64, the line connecting one end of the second slot section 612 and one end of the third slot section 613 in the second surface 65 forms a first connecting line W, the line connecting the other end of the second slot section 612 and the other end of the third slot section 613 in the second surface 65 forms another first connecting line W, the first slot section 611 is located between the two first connecting lines W, a part of the second slot section 612, the first slot section 611, a part of the third slot section 613 and a first connecting line W are connected end to end to enclose a predetermined pressure relief area 63, another part of the second slot section 612, the first slot section 611, another part of the third slot section 613 and another first connecting line W are connected end to end to enclose another predetermined pressure relief area 63, Fig.10 The two shaded parts shown in FIG. 6 are two predetermined pressure relief areas 63 .

[0273] In this embodiment, the first groove section 611 connects the second groove section 612 and the third groove section 613, so that the intersection of the first groove section 611 and the second groove section 612 and the connection position of the first groove section 611 and the third groove section 613 are weaker, and are more likely to be split 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 to each other, and the first groove section 611 and the second groove 62 are arranged at intervals along the width direction Z of the second groove. 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, which can further increase the opening 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.

[0274] 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 .

[0275] 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, that is, the connection position between the second slot segment 612 and the first slot segment 611 is not located at any one of the two ends of the second slot segment 612, and 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 can be deviated from the midpoint of the second slot segment 612.

[0276] 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, that is, the connection position between the third slot segment 613 and the first slot segment 611 is not located at any one of the two ends of the third slot segment 613, and 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 two 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 can be deviated from the midpoint of the third slot segment 613.

[0277] 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.

[0278] 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 improve the pressure relief rate of the battery cell 10.

[0279] In some embodiments, the first slot segment 611 extends along a straight line or an arc track; and / or the second slot segment 612 extends along a straight line or an arc track; and / or the third slot segment 613 extends along a straight line or an arc track. If the first slot segment 611 extends along a straight line track, the first slot segment 611 is a straight slot, which can reduce the difficulty of forming the first slot segment 611.

[0280] As an example, in Fig.10 In the illustrated embodiment, the first slot segment 611 , the second slot segment 612 , and the third slot segment 613 all extend along a straight line, and the second slot segment 612 and the third slot segment 613 are both perpendicular to the first slot segment 611 .

[0281] 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 is depressurized, so that the predetermined pressure relief area 63 is opened 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 is depressurized, so that the predetermined pressure relief area 63 is opened 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 split along the third groove section 613 when the battery cell 10 releases pressure, so that the predetermined pressure relief area 63 is opened more quickly.

[0282] In some embodiments, please refer to Fig.17 and Fig.18 , Fig.17 A partial view of a housing 1 provided for some further embodiments of the present application; Fig.18 for Fig.17 The HH cross-sectional view of the housing 1 is shown. The first groove 61 extends along an arc trajectory.

[0283] 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.

[0284] As an example, in Fig.17 and Fig.18 In the illustrated embodiment, the first groove 61 is disposed on the second surface 65 , the second groove 62 is disposed on the first surface 64 , the line connecting the two ends of the first groove 61 forms a first line W, and the first groove 61 and the first line W are connected end to end to enclose a predetermined pressure relief area 63 .

[0285] 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 includes only one groove segment, which simplifies the structure of the first groove 61.

[0286] In some embodiments, please refer to Fig.10 , Fig.15 and Fig.17 The second groove 62 extends along a straight track. The second groove 62 is a straight groove with a simple structure and is easy to process and shape.

[0287] In some embodiments, please refer to Fig.19 , Fig.19An exploded view of a housing 1 (an opening is formed at one end of the housing 11 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.

[0288] It can be understood that a part of the first wall portion 13 can be used as the pressure relief component 6; or the first wall portion 13 can be used as the pressure relief component 6 as a whole, 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 is the thickness direction of the pressure relief component 6, and 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.

[0289] 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 to form an integrated pressure relief structure with higher reliability, eliminating the installation process of the pressure relief component 6 and having better economy.

[0290] In some embodiments, please refer to Fig. 20 , Fig. 20 An exploded view of a housing 1 (an opening is formed at one end of the housing 11, the end cover 12 is a first wall portion 13, and a pressure relief component 6 is installed on the first wall portion 13) provided in some embodiments of the present application. The pressure relief component 6 is separately provided from the first wall portion 13, and the pressure relief component 6 is installed on the first wall portion 13.

[0291] The pressure relief component 6 and the housing 1 are two separate components, and the pressure relief component 6 can be produced separately and then installed on the first wall portion 13. The pressure relief component 6 can be installed on the first wall portion 13 by welding, riveting, bonding, etc. 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 the pressure relief component 6 is welded to the first wall portion 13.

[0292] 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.

[0293] In some embodiments, the first groove 61 is stamped and formed on the pressure relief component 6 .

[0294] It is understandable that the first groove 61 is formed on the pressure relief component 6 by stamping. If the first groove 61 is a primary groove structure, when the first groove 61 is formed on the pressure relief component 6, the first wall portion 13 may be stamped once to stamp out the first groove 61 on the pressure relief component 6; if the first groove 61 is a multi-stage groove structure, when the first groove 61 is formed on the pressure relief component 6, the pressure relief component 6 may be stamped multiple times, each time a primary groove is stamped out, and the first groove 61 is finally formed after multiple stampings. It is understandable 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 on the first wall portion 13.

[0295] 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 .

[0296] In some embodiments, the second groove 62 is stamped and formed on the pressure relief component 6 .

[0297] It is understandable that the second groove 62 is formed on 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 and formed on the first wall portion 13 .

[0298] 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 to reducing the production cost of the battery cell 10 .

[0299] 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 .

[0300] The housing 1 may be in a rectangular parallelepiped shape, and the first wall portion 13 may be any rectangular wall portion in the housing 1. The first wall portion 13 is a rectangular wall portion, that is, the first wall portion 13 is substantially in a rectangular shape when viewed along the thickness direction X of the first wall portion. The length of the first wall portion 13 is greater than the width of the first wall portion 13.

[0301] 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 may 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 may be 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 are just connected in the width direction of the first wall portion 13.

[0302] As an example, the width direction of the first wall portion 13 is parallel to the width direction Z of the second groove.

[0303] 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, so that the area where the second groove 62 is arranged in the pressure relief component 6 has a higher strength, reducing the risk of the pressure relief component 6 being cracked along the second groove 62 when the battery cell 10 releases pressure. In addition, during the normal use of the battery cell 10, the expansion amount of the battery cell 10 in the width direction of the first wall portion 13 is greater than the expansion amount in the length direction of the first wall portion 13, and the expansion of the battery cell 10 in the width direction of the first wall portion 13 has a greater impact on the pressure relief component 6, and the first groove 61 and the second groove 62 are arranged along the width direction of the first wall portion 13, and the second groove 62 can absorb the deformation energy of the battery cell 10 when the battery cell 10 expands and deforms along 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 component 6.

[0304] In some embodiments, please refer to Fig.19 and Fig. 20 The housing 1 comprises a shell 11 and an end cover 12. The shell 11 has an opening at at least one end. The end cover 12 corresponds to the opening one by one and closes the opening. At least one end cover 12 is a first wall portion 13.

[0305] The shell 11 may have only one opening, for example, the shell 11 has an opening at only one end; the shell 11 may also have multiple openings, for example, the shell 11 has openings at both opposite ends. The number of end caps 12 is the same as the number of openings of the shell 11. It is understandable that if the shell 11 has only one opening, there is one end cap 12, and the end cap 12 is the first wall portion 13; if the shell 11 has two openings, there are two end caps 12, and one end cap 12 may be the first wall portion 13, or both end caps 12 may be the first wall portion 13.

[0306] In an embodiment where the housing 11 is opened at one end, the positive electrode terminal and the negative electrode terminal may be provided at the end cap 12, and the positive electrode ear and the negative electrode ear may be formed at one end of the electrode assembly 2 facing the end cap 12, so as to be electrically connected to the positive electrode terminal and the negative electrode terminal, respectively. In an embodiment where openings are formed at both opposite ends of the housing 11, the positive electrode terminal may be provided at one end cap 12, the negative electrode terminal may be provided at the other end cap 12, and the positive electrode ear and the negative electrode ear may be formed at opposite ends of the electrode assembly 2, so as to be electrically connected to the positive electrode terminal and the negative electrode terminal.

[0307] exist Fig.19 In the embodiment shown, one end of the housing 11 forms an opening, and the end cover 12 is a first wall portion 13 ( Fig.19 (not shown), the first wall portion 13 is a pressure relief component 6. Fig. 20 In the illustrated embodiment, an opening is formed at one end of the housing 11 , the end cover 12 is a first wall portion 13 , and the pressure relief component 6 is mounted on the first wall portion 13 .

[0308] 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 installing the pressure relief component 6 is lower.

[0309] In some embodiments, please refer to Fig.21 and Fig. 22 , Fig.21 An exploded view of a housing 1 (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) provided in some embodiments of the present application; Fig. 22 An exploded view of a housing 1 (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) provided in some embodiments of the present application. The housing 1 includes a housing 11 and an end cover 12. The housing 11 has an opening formed at least at one end. The end cover 12 corresponds to the opening one by 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.

[0310] The shell 11 may have only one opening, for example, the shell 11 has an opening at only one end; the shell 11 may also have multiple openings, for example, the shell 11 has openings at both opposite ends. The number of end caps 12 is the same as the number of openings of the shell 11. It is understood that if the shell 11 has only one opening, the end cap 12 is one; if the shell 11 has two openings, the end caps 12 are two. In the embodiment in which the shell 11 has an opening at one end, the positive electrode terminal and the negative electrode terminal may be provided at the end cap 12, and the positive electrode ear and the negative electrode ear may be formed at one end of the electrode assembly 2 facing the end cap 12, so as to be electrically connected to the positive electrode terminal and the negative electrode terminal respectively. In the embodiment in which the shell 11 has openings at both opposite ends, the positive electrode terminal may be provided at one end cap 12, the negative electrode terminal may be provided at the other end cap 12, and the positive electrode ear and the negative electrode ear may be formed at the opposite ends of the electrode assembly 2, so as to be electrically connected to the positive electrode terminal and the negative electrode terminal. In the housing 11 , one wall portion may be the first wall portion 13 , or a plurality of wall portions may be the first wall portion 13 .

[0311] In this embodiment, at least one wall portion in the housing 11 is the first wall portion 13, so that the housing 11 has a pressure relief function. When the battery cell 10 is depressurized, the emissions discharged from the inside of the battery cell 10 are not likely to affect the external components outside the end cap 12, reducing the risk of external components being damaged by emissions. The external components can be a confluence component connected to the electrode terminal, a temperature detection component, a voltage detection component, etc. The emissions include, but are not limited to: electrolyte, dissolved or split positive and negative plates, fragments of separators, high-temperature and high-pressure gas generated by the reaction, flames, etc.

[0312] In some embodiments, please refer to Fig.21 and Fig. 22 The shell 11 has an opening at only one end, and the wall portion of the shell 11 that is opposite to the end cover 12 is the first wall portion 13 .

[0313] As an example, the housing 11 is in the shape of a cuboid, and the housing 11 further includes four side walls, which are arranged around the first wall portion 13, and the four side walls and the first wall portion 13 together define a space inside the housing 11. Fig.21 In the illustrated embodiment, an opening is formed at one end of the housing 11, a wall portion of the housing 11 opposite to the end cover 12 is a first wall portion 13, and the pressure relief component 6 is the first wall portion 13. Fig. 22 In the illustrated embodiment, an opening is formed at one end of the shell 11 , and a wall portion of the shell 11 opposite to the end cover 12 is a first wall portion 13 , and the pressure relief component 6 is mounted on the first wall portion 13 .

[0314] In this embodiment, the housing 11 is an open structure at one end, making the structure of the entire battery cell 10 simpler. The first wall 13 is a wall of the housing 11 opposite to the end cover 12, and can achieve directional pressure relief from the bottom of the housing 11.

[0315] In some embodiments, please refer to Fig.23 , Fig.23 The exploded view of the battery cell 10 provided in some other embodiments of the present application. The housing 11 has openings at both opposite ends, and at least one wall portion in the housing 11 is a first wall portion 13 .

[0316] In the housing 11 , one wall portion may be the first wall portion 13 , or a plurality of walls may be the first wall portion 13 . The pressure relief component 6 may be the first wall portion 13 , or the pressure relief component 6 may be installed on the first wall portion 13 .

[0317] As an example, the housing 11 is in a rectangular parallelepiped shape and includes four wall portions, which are connected end to end in sequence and together define the space inside the housing 11. Among the four wall portions, two opposite wall portions are large-area wall portions, and the other two wall portions are small-area wall portions, and the outer surface area of ​​the large-area wall portion is larger than the outer surface area of ​​the small-area wall portion, and one or two small-area wall portions in the housing 11 are first wall portions 13.

[0318] In this embodiment, the shell 11 is a structure with openings formed at both opposite ends, and the electrode assembly 2 can be assembled into the shell 11 through any opening, which can reduce the difficulty of assembling the battery cell 10 and improve the assembly quality of the battery cell 10. The shell 11 of this structure can be made longer (openings are formed at both ends of the shell 11 in the length direction), which is conducive to increasing the capacity of the battery cell 10.

[0319] In some embodiments, the material of the pressure relief component 6 includes steel.

[0320] The steel material can be carbon steel, alloy steel, stainless steel, etc.

[0321] It is understandable 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 cover 12, the end cover 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.

[0322] In this embodiment, steel has the characteristic of high strength, and the pressure relief component 6 made of steel has better strength. When the bursting pressure of the battery cell 10 is constant, the pressure relief component 6 can be made thinner to reduce the volume of 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 steel, and the first wall portion 13 can be made thinner. When the volume of the shell 1 is constant, the volume of the shell 1 can be increased to provide more space for the electrode assembly 2, which is conducive to improving the volume energy density of the battery cell 10.

[0323] In some embodiments, the steel material is carbon steel or stainless steel.

[0324] Carbon steel can be low carbon steel, medium carbon steel or high carbon steel.

[0325] In some embodiments, the pressure relief component 6 is made of aluminum alloy.

[0326] It is understandable 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 aluminum alloy. If the first wall portion 13 is the end cover 12, the end cover 12 can be made of aluminum alloy; if the first wall portion 13 is a wall portion in the housing 11, the housing 11 can be made of aluminum alloy.

[0327] 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 increasing the service life of the battery cell 10.

[0328] 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 single elements ≤ 0.03%.

[0329] This aluminum alloy belongs to the third series aluminum, and has lower hardness and better forming ability, which reduces the difficulty of processing 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.

[0330] 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 single element components ≤ 0.05%, and the total composition of other elements ≤ 0.15%.

[0331] This aluminum alloy belongs to the fifth series aluminum, and the pressure relief component 6 made of this aluminum alloy has higher hardness, greater strength, and good anti-destruction ability. The present application embodiment provides a battery 100, including the battery cell 10 provided by any of the above embodiments.

[0332] An embodiment of the present application provides a battery 100, comprising a battery cell 10 provided in any one of the above embodiments.

[0333] An embodiment of the present application provides an electrical device, including 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.

[0334] The embodiment of the present application also provides a battery cell 10, which includes a housing 1 and an electrode assembly 2, wherein the electrode assembly 2 has a positive electrode ear and a negative electrode ear, and the electrode assembly 2 is accommodated in the housing 1. The housing 1 is in the shape of a rectangular parallelepiped, and includes a shell 11 and an end cover 12, wherein an opening is formed at one end of the shell 11, and the end cover 12 closes the opening, and a positive electrode terminal and a negative electrode terminal are provided on the end cover 12, wherein the positive electrode terminal is electrically connected to the positive electrode ear through a current collecting member 4, and the negative electrode terminal is electrically connected to the negative electrode ear through another current collecting member 4.

[0335] Please refer to Figure 9-12The wall portion of the housing 11 opposite to the end cover 12 is a pressure relief component 6, which is a rectangular wall portion. The outer surface of the pressure relief component 6 is provided with a first groove 61, and the inner surface of the pressure relief component 6 is provided with two second grooves 62. 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 groove 62 is spaced 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 is an H-shaped structure. The first groove 61 includes a first groove section 611, a second groove section 612 and a third groove section 613. The first groove section 611, the second groove section 612 and the third groove section 613 all extend along a straight line. The second groove section 612 and the third groove section 613 are arranged in parallel. The first groove section 611 connects the second groove section 612 and the third groove section 613. The second groove section 612 and the third groove section 613 are both perpendicular to the first groove section 611. The connection position between the first groove section 611 and the second groove section 612 is located at the midpoint of the second groove section 612. The connection position between the first groove section 611 and the third groove section 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 the second groove section 612 and the third groove section 613 at both ends of the extension direction. The first groove 61 is a stepped groove. The first groove 61 includes two-stage grooves, and each stage of the groove is an H-shaped structure. The first groove section 611, the second groove section 612, and the third groove section 613 jointly define two predetermined pressure relief areas 63, each predetermined pressure relief area 63 is arranged corresponding to a second groove 62, and the pressure relief component 6 is configured to be able to split along at least a portion of the first groove 61 when the battery cell 10 is depressurized, and the second groove 62 is configured to guide at least a portion of the predetermined pressure relief area 63 to flip over to open 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 arranged oppositely 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, which satisfies: 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.

[0336] In such a battery cell 10, 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 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.

[0337] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0338] The above embodiments are only used to illustrate the technical solution of the present application and are not used to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: The housing comprises a first wall portion, wherein the first wall portion is provided with a first groove and a second groove, wherein the first groove defines at least one predetermined pressure relief zone, wherein the first wall portion is configured to be split along at least a portion of the first groove when the battery cell is pressure-released, wherein the first wall portion has a first surface and a second surface opposite to each other along a thickness direction of the first wall portion, wherein the second groove is recessed from the first surface toward a direction close to the second surface, and wherein the second groove is configured to guide at least a portion of the predetermined pressure relief zone to flip, so as to open at least a portion of the predetermined pressure relief zone; Among them, along the width direction of the second groove, the second groove includes a first groove side surface and a second groove side surface which are relatively 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 first groove side surface and the first surface The angle is a, and the angle between 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, characterized in that: 90°≤a≤150°; and / or, 90°<b≤170°.

3. The battery cell according to claim 1, characterized in that: The second groove also 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: L1<L2.

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

5. The battery cell according to claim 1, characterized in that: The minimum residual thickness of the first groove is D1, and the minimum residual thickness of the second groove is D2, satisfying: D1<D2.

6. The battery cell according to claim 5, characterized in that: 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: H2<H1.

7. The battery cell according to claim 5, characterized in that: 0.3mm≤D2≤1.2mm.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The first wall portion is provided with a plurality of the second grooves, the first grooves define a plurality of the predetermined pressure relief areas, and each of the predetermined pressure relief areas is provided corresponding to at least one of the second grooves.

9. The battery cell according to claim 8, characterized in that: There are two predetermined pressure relief areas and two second grooves; The first groove includes a first groove section. Along the width direction of the second groove, the first groove section is located between two second grooves. The two predetermined pressure relief areas are respectively located on both sides of the first groove section. 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 to 7, characterized in that: Along the thickness direction of the first wall portion, a projection of the second groove does not overlap with a projection of the first groove.

11. The battery cell according to claim 10, characterized in that: Along a width direction of the second groove, the second groove is spaced apart from the first groove.

12. The battery cell according to any one of claims 1 to 7, characterized in that: Along the thickness direction of the first wall portion, two ends of the projection of the second groove along the extension direction respectively extend out of two end portions of the projection of the first groove.

13. The battery cell according to any one of claims 1 to 7, characterized in that: The first groove is recessed from the second surface toward the first surface.

14. The battery cell according to claim 13, characterized in that: Along the width direction of the second groove, projections of the first groove and the second groove at least partially overlap.

15. The battery cell according to claim 13, characterized in that: Along the thickness direction of the first wall portion, a groove bottom surface of the second groove is closer to the second surface than a groove bottom surface of the first groove.

16. The battery cell according to claim 13, characterized in that: 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: D1<H2.

17. The battery cell according to claim 13, characterized in that: The first groove comprises a plurality of grooves arranged in sequence along the direction from the second surface to the first surface, and along the thickness direction of the first wall portion, in two adjacent grooves, the first groove away from the second surface is arranged at the groove bottom surface of the first groove close to the second surface; Among the multi-stage grooves, the first-stage groove arranged on the second surface is a first-stage groove, and along the width direction of the second groove, the projection of the second groove and the first-stage groove at least partially overlap.

18. The battery cell according to claim 17, characterized in that: Along the thickness direction of the first wall portion, the groove bottom surface of the second groove is closer to the second surface than the groove bottom surface of the first-stage groove.

19. The battery cell according to any one of claims 1 to 7, characterized in that: The first groove is recessed from the first surface toward the second surface.

20. The battery cell according to claim 19, characterized in that The first groove comprises a plurality of grooves arranged in sequence along a direction from the first surface to the second surface, and along a thickness direction of the first wall portion, in two adjacent grooves, a first-level groove away from the first surface is arranged at a groove bottom surface of a first-level groove close to the first surface; Among them, the first-level groove in the multi-level grooves arranged on the first surface is a first-level groove, and along the thickness direction of the first wall portion, the groove bottom surface of the first-level groove is closer to the first surface than the groove bottom surface of the second groove.

21. The battery cell according to claim 20, characterized in that 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-level groove is H3, satisfying: H3<H2.

22. The battery cell according to any one of claims 1 to 7, characterized in that: The first surface is a surface of the first wall portion facing the interior of the housing.

23. The battery cell according to any one of claims 1 to 7, characterized in that: The first surface is a surface of the first wall portion facing the outside of the housing.

24. The battery cell according to any one of claims 1 to 7, characterized in that: 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 predetermined pressure relief area.

25. The battery cell according to any one of claims 1 to 7, characterized in that: 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 to each other, 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 are arranged at intervals, and the first groove section, the second groove section and the third groove section jointly define at least one predetermined pressure relief area.

26. The battery cell according to claim 25, characterized in that The connection position between the second slot section and the first slot section deviates from the two ends of the second slot section, and the connection position between the third slot section and the first slot section deviates from the two ends of the third slot section, so that the predetermined pressure relief area is formed on both sides of the first slot section.

27. The battery cell according to claim 25, characterized in that 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.

28. The battery cell according to any one of claims 1 to 7, characterized in that: The first groove extends along an arc trajectory.

29. The battery cell according to any one of claims 1 to 7, characterized in that: The second groove extends along a straight line trajectory.

30. The battery cell according to any one of claims 1 to 7, characterized in that: The first groove is stamped and formed on the first wall portion; and / or the second groove is stamped and formed on the first wall portion.

31. The battery cell according to any one of claims 1 to 7, characterized in that: The first wall portion is a rectangular wall portion, and the first groove and the second groove are arranged along a width direction of the first wall portion.

32. The battery cell according to any one of claims 1 to 7, characterized in that: The housing comprises: A shell having an opening formed at at least one end; An end cover, corresponding to each of the openings, and closing the openings; Wherein, at least one of the end covers is the first wall portion.

33. The battery cell according to any one of claims 1 to 7, characterized in that: The housing comprises: A shell having an opening formed at at least one end; An end cover, corresponding to each of the openings, and closing the openings; Wherein, at least one wall portion in the shell is the first wall portion.

34. The battery cell according to claim 33, characterized in that The opening is formed at only one end of the shell, and the wall portion of the shell opposite to the end cover is the first wall portion.

35. The battery cell as claimed in claim 33, characterized in that The openings are formed at opposite ends of the shell, and at least one wall portion in the shell is the first wall portion.

36. The battery cell according to any one of claims 1 to 7, characterized in that: The material of the first wall portion includes steel.

37. The battery cell according to claim 36, characterized in that The steel material is carbon steel or stainless steel.

38. The battery cell according to any one of claims 1 to 7, characterized in that: The material of the first wall portion includes aluminum alloy.

39. A battery, characterized in that: Comprising the battery cell according to any one of claims 1-38.

40. An electrical device, characterized in that: It comprises a battery cell as described in any one of claims 1 to 38, and the battery cell is used to provide electrical energy to the electrical device.

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