WO2024103355A1 - 外壳部件、电池单体、电池及用电设备 - Google Patents

外壳部件、电池单体、电池及用电设备 Download PDF

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Publication number
WO2024103355A1
WO2024103355A1 PCT/CN2022/132665 CN2022132665W WO2024103355A1 WO 2024103355 A1 WO2024103355 A1 WO 2024103355A1 CN 2022132665 W CN2022132665 W CN 2022132665W WO 2024103355 A1 WO2024103355 A1 WO 2024103355A1
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WO
WIPO (PCT)
Prior art keywords
groove
shell
weak area
battery cell
housing component
Prior art date
Application number
PCT/CN2022/132665
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English (en)
French (fr)
Inventor
陈小波
顾明光
Original Assignee
宁德时代新能源科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Priority to PCT/CN2022/132665 priority Critical patent/WO2024103355A1/zh
Publication of WO2024103355A1 publication Critical patent/WO2024103355A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/103—Primary casings; Jackets or wrappings characterised by their shape or physical structure prismatic or rectangular
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/204—Racks, modules or packs for multiple batteries or multiple cells
    • H01M50/207—Racks, modules or packs for multiple batteries or multiple cells characterised by their shape
    • H01M50/209—Racks, modules or packs for multiple batteries or multiple cells characterised by their shape adapted for prismatic or rectangular cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/249—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders specially adapted for aircraft or vehicles, e.g. cars or trains
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/342—Non-re-sealable arrangements

Definitions

  • the present application relates to the field of battery technology, and in particular to a housing component, a battery cell, a battery and an electrical device.
  • 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.
  • the embodiments of the present application provide a housing component, a battery cell, a battery and an electrical device, which can effectively increase the service life of the battery.
  • an embodiment of the present application provides a shell component for a battery cell, comprising an integrally formed non-weak area and a weak area, the shell component is provided with a groove portion, the non-weak area is formed around the groove portion, the weak area is formed at the bottom of the groove portion, and the weak area is configured to be destroyed when the battery cell releases internal pressure; wherein the average grain size of the weak area is S 1 , and the average grain size of the non-weak area is S 2 , satisfying: S 1 /S 2 ⁇ 0.9.
  • the average grain size of the weak area is significantly different from the average grain size of the non-weak area, the average grain size of the weak area is reduced, the mechanical properties of the material in the weak area are improved, the toughness and fatigue strength of the weak area are improved, the risk of the weak area being damaged under normal use conditions of the battery cell is reduced, and the service life of the battery cell is increased.
  • S 1 /S 2 ⁇ 0.05 If S 1 /S 2 is too small, the difficulty of forming the weak area increases, and if the strength of the weak area is too large, the difficulty of destroying the weak area during thermal runaway of the battery cell increases, and the pressure relief is prone to be delayed. Therefore, S 1 /S 2 ⁇ 0.05 reduces the difficulty of forming the weak area and improves the timeliness of pressure relief of the battery cell during thermal runaway.
  • 0.4 ⁇ m ⁇ S 1 ⁇ 75 ⁇ m If S 1 is too large, the toughness and fatigue resistance of the weak zone are poor; if S 1 is too small, the molding of the weak zone is difficult, and the strength of the weak zone is too large, which increases the difficulty of destroying the weak zone during thermal runaway of the battery cell, and it is easy to cause untimely pressure relief. Therefore, 0.4 ⁇ m ⁇ S 1 ⁇ 75 ⁇ m, on the one hand, reduces the difficulty of molding the weak zone and improves the timeliness of pressure relief of the battery cell during thermal runaway; on the other hand, it improves the toughness and fatigue resistance of the weak zone and reduces the risk of the weak zone being destroyed under normal use conditions of the battery cell.
  • 1 ⁇ m ⁇ S 1 ⁇ 10 ⁇ m 1 ⁇ m ⁇ S 1 ⁇ 10 ⁇ m. This makes the overall performance of the housing component better, ensures that the weak area can be destroyed in time when the battery cell is in thermal runaway, and ensures that the weak area has sufficient strength under normal use conditions of the battery cell.
  • the minimum thickness of the weak zone is A, which satisfies: 1 ⁇ A/S 1 ⁇ 100. If A/S 1 is too small, the number of grain layers in the weak zone in the thickness direction of the weak zone is smaller, and the fatigue strength of the weak zone is too small; if A/S 1 is too large, the number of grain layers in the weak zone in the thickness direction of the weak zone is too large, and the strength of the weak zone is too large, which may lead to the risk that the weak zone cannot be destroyed in time when the battery cell is in thermal runaway.
  • 1 ⁇ A/S 1 ⁇ 100 makes the number of grain layers in the thickness direction of the weak zone larger, improves the fatigue strength of the weak zone, and reduces the risk of the weak zone being destroyed under normal use conditions of the battery cell; on the other hand, it enables the weak zone to be destroyed more promptly when the battery cell is in thermal runaway, so as to achieve the purpose of timely pressure relief.
  • 5 ⁇ A/S 1 ⁇ 20 This makes the overall performance of the housing component better, ensures that the weak area can be destroyed in time when the battery cell is in thermal runaway, ensures that the weak area has sufficient fatigue resistance under normal use conditions of the battery cell, and improves the service life of the battery cell.
  • the minimum thickness of the weak area is A
  • the hardness of the weak area is H 1 , which satisfies: 5HBW/mm ⁇ H 1 /A ⁇ 10000HBW/mm.
  • 5HBW/mm ⁇ H 1 /A ⁇ 10000HBW/mm can not only make the weak area have sufficient strength under the normal use conditions of the battery cell, and the weak area is not easily damaged by fatigue, thereby improving the service life of the battery cell; but also can make the shell component release pressure through the weak area in time when the battery cell is thermally runaway, thereby reducing the risk of explosion of the battery cell and improving the safety of the battery cell.
  • 190HBW/mm ⁇ H 1 /A ⁇ 4000HBW/mm This makes the overall performance of the housing component better, ensures that the weak area can be destroyed in time when the battery cell is in thermal runaway, and ensures that the weak area has sufficient strength under normal use conditions of the battery cell. Under the premise of ensuring the safety of the battery cell, the service life of the battery cell is improved.
  • 0.02mm ⁇ A ⁇ 1.6mm If A is too small, the molding difficulty of the weak zone is difficult, and the weak zone is easily damaged during the molding process; if A is too large, the difficulty of destroying the weak zone during thermal runaway of the battery cell increases, and the pressure relief is likely to be delayed. Therefore, 0.02mm ⁇ A ⁇ 1.6mm improves the timeliness of pressure relief of the battery cell during thermal runaway while reducing the molding difficulty of the pressure relief zone.
  • 0.06 mm ⁇ A ⁇ 0.4 mm This further reduces the difficulty of forming the pressure relief zone and improves the timeliness of pressure relief of the battery cell during thermal runaway.
  • the hardness of the weak area is H 1
  • the hardness of the non-weak area is H 2 , satisfying: H 1 > H 2 . This is equivalent to increasing the hardness of the weak area, thereby increasing the strength of the weak area and reducing the risk of the weak area being damaged under normal use conditions of the battery cell.
  • H 1 /H 2 ⁇ 5 reduces the risk that the weak area cannot be destroyed in time when the battery cell thermal runaways, thereby improving the safety of the battery cell.
  • H 1 /H 2 ⁇ 2.5.
  • the minimum thickness of the weak area is A
  • the minimum thickness of the non-weak area is B, satisfying: 0.05 ⁇ A/B ⁇ 0.95. If A/B is too small, the strength of the weak area may be insufficient. If A/B is too large, the weak area may not be easily destroyed when the battery cell is in thermal runaway, and the pressure relief is not timely, resulting in an increased probability of battery cell explosion. Therefore, 0.05 ⁇ A/B ⁇ 0.95 can reduce the probability of the weak area rupturing under normal use conditions of the battery cell, and reduce the probability of explosion when the battery cell is in thermal runaway.
  • 0.12 ⁇ A/B ⁇ 0.8 0.12 ⁇ A/B ⁇ 0.8. In this way, the comprehensive performance of the external components is better, and the weak area is ensured to have sufficient strength under normal use conditions of the battery cell while ensuring that the weak area can be destroyed in time when the battery cell is in thermal runaway.
  • 1mm ⁇ B ⁇ 5mm In some embodiments, 1mm ⁇ B ⁇ 5mm. If B is too large, the thickness of the non-weak area is large, more materials are used for the shell component, the weight of the shell component is large, and the economic efficiency is poor. If B is too small, the thickness of the non-weak area is small, and the anti-deformation ability of the shell component is poor. Therefore, 1mm ⁇ B ⁇ 5mm makes the shell component have better economic efficiency and better anti-deformation ability.
  • 1.2 mm ⁇ B ⁇ 3.5 mm so that the housing component has better economy and anti-deformation ability.
  • the housing component has a pressure relief area
  • the groove portion includes a primary notch groove
  • the notch groove is arranged along the edge of the pressure relief area
  • the pressure relief area is configured to be able to open with the notch groove as a boundary
  • the weak area forms the bottom of the notch groove.
  • the housing component has a first surface and a second surface that are arranged opposite to each other, and the notched groove is recessed from the first surface toward the second surface.
  • the notched groove is a groove portion, and the structure is simple. During molding, the notched groove can be molded on the first surface, which is simple to mold, improves production efficiency, and reduces production costs.
  • the shell component includes a first surface and a second surface that are arranged opposite to each other, the groove portion includes a multi-level notch groove, the multi-level notch groove is sequentially arranged on the shell component along the direction from the first surface to the second surface, and the weak area is formed at the bottom of the first-level notch groove farthest from the first surface; wherein the shell component has a pressure relief area, each level of notch groove is arranged along the edge of the pressure relief area, and the pressure relief area is configured to be able to open with the first-level notch groove farthest from the first surface as a boundary.
  • the multi-level notch groove can be molded step by step on the shell component, which can reduce the molding depth of each level of notch groove, thereby reducing the molding force on the shell component when molding each level of notch groove, reducing the risk of cracks in the shell component, and the shell component is not easy to fail due to cracks at the position where the notch groove is set, thereby increasing the service life of the shell component.
  • the primary notch groove farthest from the second surface is recessed from the first surface toward the second surface.
  • the groove portion is composed of multiple notches, and during molding, the multiple notches can be gradually processed from the first surface to the second surface.
  • the shell component includes a first surface and a second surface that are arranged opposite to each other, and the groove portion further includes a primary groove, the groove is recessed from the first surface toward the second surface, and the pressure relief zone is formed on the bottom wall of the groove.
  • the arrangement of the groove can reduce the depth of the notched groove while ensuring that the thickness of the final weak zone is constant, thereby reducing the forming force on the shell component when forming the notched groove and reducing the risk of cracks in the shell component.
  • the groove can provide an escape space for the pressure relief zone during the opening process, and even if the first surface is blocked by an obstacle, the pressure relief zone can still be opened to relieve pressure.
  • the shell component includes a first surface and a second surface that are arranged opposite to each other, and the groove portion also includes a multi-stage groove.
  • the multi-stage groove is sequentially arranged on the shell component along the direction from the first surface to the second surface, and the first-stage groove farthest from the second surface is recessed from the first surface to the second surface, and the pressure relief zone is formed on the bottom wall of the first-stage groove farthest from the first surface.
  • the multi-stage groove can provide an escape space for the pressure relief zone during the opening process, and even if the first surface is blocked by an obstacle, the pressure relief zone can still be opened to relieve pressure.
  • the internal space of the sink is a cylinder, a prism, a truncated cone or a prism.
  • the sink of this structure is simple in structure, easy to shape, and can provide more avoidance space for the pressure relief area during the opening process.
  • the notched groove includes a first groove section and a second groove section, the first groove section intersects with the second groove section, and the first groove section and the second groove section are arranged along the edge of the pressure relief zone.
  • the stress at the intersection of the first groove section and the second groove section is more concentrated, so that the weak area can be first destroyed at the intersection of the first groove section and the second groove section.
  • the weak area can be made thicker to reduce the molding depth of the notched groove.
  • the notched groove further includes a third groove section, the first groove section and the third groove section are arranged opposite to each other, the second groove section intersects with the third groove section, and the first groove section, the second groove section and the third groove section are arranged along the edge of the pressure relief zone.
  • the pressure relief zone can be opened with the first groove section, the second groove section and the third groove section as the boundary, and when the battery cell is depressurized, the pressure relief zone is opened more easily, thereby realizing large-area pressure relief of the housing component.
  • first trough section, the second trough section and the third trough section are connected in sequence, and the first trough section, the second trough section and the third trough section define a pressure relief area.
  • the first slot segment, the second slot segment and the third slot segment define two pressure relief areas, and the two pressure relief areas are respectively located on both sides of the second slot segment.
  • the two pressure relief areas can be opened in a split form to relieve pressure, which can effectively improve the pressure relief efficiency of the housing component.
  • the notched groove is a groove extending along a non-closed track.
  • the pressure relief area can be opened in a flipping manner, and the pressure relief area is finally connected to other areas of the housing component after opening, reducing the risk of splashing after the pressure relief area is opened.
  • the notched groove is an arc-shaped groove.
  • the arc-shaped groove has a simple structure and is easy to form. During the pressure relief process, the pressure relief area can be quickly ruptured along the arc-shaped groove, so that the pressure relief area is quickly opened.
  • the notched groove is a groove extending along a closed track.
  • the shell component can be broken along the notched groove, so that the pressure relief area can be opened in a disengaged manner, thereby increasing the pressure relief area of the shell component and improving the pressure relief rate of the shell component.
  • the notched groove is an annular groove.
  • the annular groove has a simple structure and is easy to form. During the pressure relief process, the shell component can be quickly broken along the annular groove to quickly open the pressure relief area.
  • the area of the pressure relief zone is D, which satisfies: 90mm 2 ⁇ D ⁇ 1500mm 2 . If D is too small, the pressure relief area of the housing component is small, and the timeliness of pressure relief during thermal runaway of the battery cell is poor; if D is too large, the impact resistance of the pressure relief zone is poor, the deformation of the pressure relief zone after being stressed increases, and the weak area is easily damaged under normal use conditions of the battery cell, affecting the service life of the battery cell. Therefore, 90mm 2 ⁇ D ⁇ 1500mm 2 can not only improve the service life of the battery cell, but also improve the safety of the battery cell.
  • 150 mm 2 ⁇ D ⁇ 1200 mm 2 In some embodiments, 150 mm 2 ⁇ D ⁇ 1200 mm 2 .
  • 200 mm 2 ⁇ D ⁇ 1000 mm 2 In some embodiments, 200 mm 2 ⁇ D ⁇ 1000 mm 2 .
  • 250 mm 2 ⁇ D ⁇ 800 mm 2 In some embodiments, 250 mm 2 ⁇ D ⁇ 800 mm 2 .
  • the housing component has a first surface and a second surface that are arranged opposite to each other, the groove portion is recessed from the first surface toward the second surface, the groove portion forms an outer edge on the first surface, and the area of the housing component outside a preset distance from the outer edge is a non-weak area. In this way, the non-weak area is not easily affected by the process of forming the groove portion, so that the grains in the non-weak area are more uniform.
  • the housing component further includes a transition zone, the transition zone connects the weak zone and the non-weak zone, the average grain size of the transition zone is S 3 , and S 3 ⁇ S 2 .
  • the transition zone connects the weak zone and the non-weak zone to achieve integrated molding of the weak zone and the non-weak zone.
  • the housing component is an end cap, which is used to close the opening of the housing, and the housing is used to accommodate the electrode assembly, so that the end cap has a pressure relief function to ensure the safety of the battery cell.
  • the outer shell component is a shell having an opening, and the shell is used to accommodate the electrode assembly, so that the shell has a pressure relief function to ensure the safety of the battery cell.
  • the housing includes a plurality of integrally formed walls, the plurality of walls together define an internal space of the housing, and at least one wall is provided with a groove.
  • the plurality of walls are integrally formed so that the wall provided with the groove has better reliability.
  • the multiple wall portions include a bottom wall and multiple side walls surrounding the bottom wall, and the shell forms an opening at an end opposite to the bottom wall; the bottom wall is provided with a groove portion; and/or at least one side wall is provided with a groove portion.
  • the housing is a rectangular parallelepiped, which is suitable for square battery cells and can meet the large capacity requirements of battery cells.
  • the material of the housing component includes aluminum alloy.
  • the housing component of aluminum alloy is light in weight, has good ductility, and is easy to form.
  • the aluminum alloy includes the following components by mass percentage: aluminum ⁇ 99.6%, copper ⁇ 0.05%, iron ⁇ 0.35%, magnesium ⁇ 0.03%, manganese ⁇ 0.03%, silicon ⁇ 0.25%, titanium ⁇ 0.03%, vanadium ⁇ 0.05%, zinc ⁇ 0.05%, and other single elements ⁇ 0.03%.
  • This aluminum alloy has lower hardness, better forming ability, reduces the difficulty of forming the groove, improves the forming accuracy of the groove, and improves the pressure relief consistency of the shell components.
  • 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 total components ⁇ 0.15%.
  • the housing parts made of such aluminum alloy have higher hardness, greater strength, and good anti-destruction ability.
  • an embodiment of the present application provides a battery cell, comprising a housing component provided by any one of the embodiments of the first aspect above.
  • the battery cell further includes a shell having an opening, and the shell is used to accommodate the electrode assembly; the outer shell component is an end cover, and the end cover closes the opening.
  • the housing component is a shell having an opening, and the shell is used to accommodate the electrode assembly; the battery cell also includes an end cover, which closes the opening.
  • an embodiment of the present application provides a battery, comprising a battery cell provided by any one of the embodiments of the second aspect above.
  • the weak area is located at the bottom of the battery cell. During the use of the battery, the weak area will be subjected to a large force under the gravity of the electrode assembly, electrolyte, etc. inside the battery cell. Since the weak area and the non-weak area are an integrated structure, it has good structural strength and better reliability, thereby increasing the service life of the battery cell.
  • the battery cell includes a shell, which is used to accommodate an electrode assembly.
  • the shell includes a bottom wall and multiple side walls surrounding the bottom wall.
  • the bottom wall and the side walls are integrally formed.
  • the shell forms an opening at one end opposite to the bottom wall, and the weak area is located on the bottom wall.
  • the battery cell includes an end cover, which is used to close an opening of a shell, and the shell is used to accommodate the electrode assembly, and the weak area is located at the end cover.
  • an embodiment of the present application provides an electrical device, comprising a battery provided by any one of the embodiments of the third aspect above.
  • FIG1 is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application.
  • FIG2 is an exploded view of a battery provided in some embodiments of the present application.
  • FIG3 is an exploded view of a battery cell provided in some embodiments of the present application.
  • FIG4 is a schematic structural diagram of a housing component provided in some embodiments of the present application.
  • Fig. 5 is a C-C sectional view of the housing component shown in Fig. 4;
  • FIG6 is a grain map (schematic diagram) of the housing component shown in FIG5 ;
  • FIG7 is a partial enlarged view of the portion E of the housing component shown in FIG5 ;
  • FIG8 is a partial enlarged view of a housing component provided in some other embodiments of the present application.
  • FIG9 is a schematic structural diagram of a housing component provided in some other embodiments of the present application (showing a primary notch groove);
  • Fig. 10 is a cross-sectional view of the housing component taken along line E-E shown in Fig. 9;
  • FIG11 is a schematic structural diagram of a housing component provided in some other embodiments of the present application (showing a primary notch groove);
  • Fig. 12 is a cross-sectional view of the housing component taken along line F-F shown in Fig. 11;
  • FIG13 is a schematic structural diagram of a housing component provided in some other embodiments of the present application (showing a primary notch groove);
  • Fig. 14 is a G-G cross-sectional view of the housing component shown in Fig. 13;
  • FIG15 is a schematic structural diagram of a housing component provided in some other embodiments of the present application (showing two-level notch grooves);
  • Fig. 16 is a cross-sectional view of the housing component taken along line K-K shown in Fig. 15;
  • FIG17 is a schematic structural diagram of a housing component provided in some other embodiments of the present application (showing two-level notch grooves);
  • Fig. 18 is a cross-sectional view of the housing component taken along line M-M shown in Fig. 17;
  • FIG19 is a schematic structural diagram of a housing component provided in some other embodiments of the present application (showing two-level notch grooves);
  • Fig. 20 is a cross-sectional view of the housing component taken along line N-N shown in Fig. 19;
  • FIG21 is an isometric view of a housing component provided in some embodiments of the present application.
  • FIG22 is a schematic structural diagram of the housing component shown in FIG21 (showing a primary scoring groove and a primary sink groove);
  • Fig. 23 is a cross-sectional view of the housing component taken along line O-O shown in Fig. 22;
  • FIG24 is a schematic structural diagram of a housing component provided in some other embodiments of the present application (showing a primary notch groove and a primary sink groove);
  • Fig. 25 is a P-P cross-sectional view of the housing component shown in Fig. 24;
  • FIG26 is a schematic structural diagram of a housing component provided in some other embodiments of the present application (showing a primary notch groove and a primary sink groove);
  • Fig. 27 is a Q-Q cross-sectional view of the housing component shown in Fig. 26;
  • FIG28 is a schematic diagram of the structure of a housing component provided in some embodiments of the present application (showing a primary scoring groove and a two-stage sinking groove);
  • Fig. 29 is a cross-sectional view of the housing component shown in Fig. 28 taken along line R-R;
  • FIG30 is a schematic structural diagram of a housing component provided in some other embodiments of the present application (showing a primary scoring groove and a two-stage sinking groove);
  • Fig. 31 is a S-S sectional view of the housing component shown in Fig. 30;
  • FIG32 is a schematic structural diagram of a housing component provided in some other embodiments of the present application (showing a primary notch groove and a two-stage sink groove);
  • Fig. 33 is a T-T cross-sectional view of the housing component shown in Fig. 32;
  • FIG34 is a schematic structural diagram of a housing component provided in some embodiments of the present application (showing a primary notch groove, which is V-shaped);
  • FIG35 is a schematic structural diagram of a housing component provided in another embodiment of the present application.
  • FIG36 is a grain map (schematic diagram) of a housing component provided in some other embodiments of the present application.
  • FIG37 is a schematic diagram of the structure of an end cap provided in some embodiments of the present application.
  • FIG38 is a schematic diagram of the structure of a housing provided in some embodiments of the present application.
  • FIG39 is a schematic diagram of the structure of a housing provided in some other embodiments of the present application.
  • FIG40 is a schematic diagram of the structure of a battery cell provided in some embodiments of the present application.
  • Icons 1-housing; 11-end cap; 12-housing; 121-wall; 121a-side wall; 121b-bottom wall; 2-electrode assembly; 21-positive ear; 22-negative ear; 3-positive electrode terminal; 4-negative electrode terminal; 5-housing component; 51-non-weak area; 511-inner edge; 52-weak area; 53-groove; 531-bottom surface of the groove; 532-notched groove; 532a-outermost primary notched groove; 532b-innermost primary notched groove; 5321-first groove section ;5322-second slot section;5323-third slot section;533-sink;533a-outermost primary sink;533b-innermost primary sink;5331-bottom wall of the sink;534-outer edge;54-first surface;55-second surface;56-pressure relief zone;57-transition zone;10-battery cell;20-casing;201-first part;202-second part;100-battery;200-
  • a and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone.
  • the character "/" in this application generally indicates that the associated objects before and after are in an "or" relationship.
  • 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.
  • the battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.
  • the battery mentioned in the embodiments of the present application may include one or more battery cells to provide a single physical module with higher voltage and capacity.
  • the multiple battery cells are connected in series, in parallel or in mixed connection through a busbar component.
  • the battery may be a battery module.
  • the multiple battery cells are arranged and fixed to form a battery module.
  • 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.
  • the box body can be used as a part of the chassis structure of the vehicle.
  • 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.
  • the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.
  • a pressure relief mechanism may be provided on the outer shell of the battery cell. When the battery cell thermally runs away, the pressure inside the battery cell is released through the pressure relief mechanism to improve the safety of the battery cell.
  • the pressure relief mechanism is welded to the outer shell to fix the pressure relief mechanism to the outer shell.
  • the pressure relief mechanism as an explosion-proof plate set on the end cover of the outer shell as an example, when the battery cell is in thermal runaway, the explosion-proof plate is destroyed to discharge the emissions inside the battery cell to achieve the purpose of releasing the pressure inside the battery cell. Since the pressure relief mechanism is welded to the outer shell, cracks may appear at the welding position during the long-term use of the battery cell, resulting in reduced strength at the welding position. It is easy for the welding position to be damaged when the pressure inside the battery cell does not reach the detonation pressure of the pressure relief mechanism, resulting in failure of the pressure relief mechanism and low reliability of the pressure relief mechanism.
  • the pressure relief mechanism and the housing can be set as an integral structure, that is, a part of the housing is used as the pressure relief mechanism.
  • a part of the end cover is weakened so that the strength of the part of the end cover is reduced to form a weak area, thereby forming an integrated pressure relief mechanism, which can effectively improve the reliability of the pressure relief mechanism.
  • an embodiment of the present application provides a shell component, wherein a groove is provided on the shell component to form an integrally formed non-weak area and a weak area, wherein the non-weak area is formed around the groove, and the weak area is formed at the bottom of the groove, the average grain size of the weak area is S 1 , and the average grain size of the non-weak area is S 2 , and S 1 /S 2 ⁇ 0.9.
  • S 1 /S 2 ⁇ 0.9 which reduces the average grain size of the weak area, improves the mechanical properties of the material in the weak area, improves the toughness and fatigue strength of the weak area, reduces the risk of the weak area being damaged under normal use conditions of the battery cell, and increases the service life of the battery cell.
  • 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.
  • FIG. 1 is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application.
  • a battery 100 is disposed inside the vehicle 1000, and the battery 100 can be disposed 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 for the vehicle 1000.
  • 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 .
  • 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.
  • FIG. 2 is an exploded view of a battery 100 provided in some embodiments of the present application.
  • the battery 100 includes a battery cell 10 and a box 20 , wherein the box 20 is used to accommodate the battery cell 10 .
  • the box body 20 is a component for accommodating the battery cell 10, and the box body 20 provides a placement space for the battery cell 10.
  • the box body 20 can adopt a variety of structures.
  • 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 placement 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 cuboid, a cylinder, etc.
  • the first part 201 may be a hollow structure with one side open
  • the second part 202 may also be a hollow structure with one side open
  • 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 placement space.
  • the first part 201 is a hollow structure with one side open
  • the second part 202 is a plate-like structure
  • the second part 202 covers the open side of the first part 201, so as to form a box body 20 with a placement space.
  • the battery cell 10 can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell 10 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, etc. There is no special limitation in the present application.
  • 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.
  • a battery module may be formed by connecting a plurality of battery cells 10 in series, in parallel, or in a mixed connection, and then the plurality of battery modules are connected in series, in parallel, or in a mixed connection to form a whole and accommodated in the box 20.
  • 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 is accommodated in the box 20.
  • FIG3 is an exploded view of a battery cell 10 provided in some embodiments of the present application.
  • the battery cell 10 may include a housing 1 and an electrode assembly 2 .
  • the housing 1 is used to accommodate the electrode assembly 2 and the electrolyte and other components.
  • the housing 1 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell) or an aluminum-plastic film, etc.
  • the housing 1 can include a shell 12 and an end cap 11.
  • the shell 12 may be a hollow structure with an opening at one end, or a hollow structure with openings at two opposite ends.
  • the shell 12 may be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, and the like.
  • the end cap 11 is a component that closes the opening of the shell 12 to isolate the internal environment of the battery cell 10 from the external environment.
  • the end cap 11 and the shell 12 together define a storage space for accommodating the electrode assembly 2, the electrolyte and other components.
  • the end cap 11 can be connected to the shell 12 by welding or crimping to close the opening of the shell 12.
  • the shape of the end cap 11 can be adapted to the shape of the shell 1.
  • the shell 12 is a rectangular parallelepiped structure, and the end cap 11 is a rectangular plate structure adapted to the shell 1.
  • the shell 12 is a cylinder, and the end cap 11 is a circular plate structure adapted to the shell 12.
  • the material of the end cap 11 can also be a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.
  • the battery cell 10 there may be one or two end caps 11.
  • two end caps 11 may be provided, and the two end caps 11 respectively close the two openings of the shell 12, and the two end caps 11 and the shell 12 together define a storage space.
  • the electrode assembly 2 includes a positive electrode, a negative electrode, and a separator.
  • active ions such as lithium ions
  • the separator is arranged between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing the active ions to pass through.
  • 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.
  • 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.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • 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 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.).
  • 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.
  • the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more.
  • lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.
  • lithium iron phosphate such as LiFePO 4 (also referred to as LFP)
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate and carbon
  • 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 LiNi1 / 3Co1 / 3Mn1 / 3O2 (also referred to as NCM333 ), LiNi0.5Co0.2Mn0.3O2 (also referred to as NCM523 ) , LiNi0.5Co0.25Mn0.25O2 (also referred to as NCM211 ) , LiNi0.6Co0.2Mn0.2O2 (also referred to as NCM622 ), LiNi0.8Co0.1Mn0.1O2 (also referred to as NCM811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O 2 ) and lithium
  • 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.
  • 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.
  • 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.
  • the negative electrode may be a negative electrode sheet, and 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.
  • 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.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • the metal foil aluminum or stainless steel treated with silver, 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 (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.).
  • the negative electrode active material may adopt the negative electrode active material for the battery known in the art.
  • 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 and 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.
  • 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.
  • the negative electrode may be a foam metal.
  • the foam metal may be foam nickel, foam copper, foam aluminum, foam alloy, or foam carbon, etc.
  • the surface of the foam metal may not be provided with a negative electrode active material, but of course, a negative electrode active material may also be provided.
  • a lithium source material, potassium metal or sodium metal may be filled or/and deposited in the negative electrode current collector, and the lithium source material is lithium metal and/or lithium-rich material.
  • the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.
  • the electrode assembly 2 further includes a separator, which is disposed between the positive electrode and the negative electrode.
  • the separator is a separator.
  • the present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.
  • the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic.
  • the separator can be a single-layer film or a multi-layer composite film, without special restrictions. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without special restrictions.
  • the separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surface of the positive and negative electrodes.
  • 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.
  • the battery cell 10 further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes.
  • an electrolyte which plays a role in conducting ions between the positive and negative electrodes.
  • the present application has no specific restrictions on the type of electrolyte, which can be selected according to needs.
  • the electrolyte can be liquid, gel or solid.
  • the liquid electrolyte includes an electrolyte salt and a solvent.
  • the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.
  • the solvent can be selected from 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 can also be selected from ether solvents.
  • Ether solvents can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.
  • the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.
  • solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.
  • 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.
  • the inorganic solid electrolyte can be an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphide, germanium argentum sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.
  • oxide solid electrolyte crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film
  • a sulfide solid electrolyte crystalline lithium superion conductor (lithium germanium phosphide, germanium argentum sulfide), amorphous sulfide)
  • a halide solid electrolyte a nitride solid electro
  • the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.
  • the electrode assembly 2 is a wound structure.
  • the positive electrode sheet and the negative electrode sheet are wound into a wound structure.
  • the electrode assembly 2 is a laminate structure.
  • 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.
  • 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.
  • both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded sections that are stacked.
  • a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.
  • the separator may be disposed continuously, and disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.
  • the shape of the electrode assembly 2 can be cylindrical, flat, or polygonal.
  • the electrode assembly 2 is provided with tabs, which can lead current out of the electrode assembly 2.
  • the tabs include a positive tab 21 and a negative tab 22.
  • the battery cell 10 may further include an electrode terminal, which may be disposed on the housing 1 and is used to electrically connect to the tab of the electrode assembly 2 to output the electrical energy of the battery cell 10.
  • the electrode terminal and the tab may be directly connected, for example, the electrode terminal and the tab are directly welded.
  • the electrode terminal and the tab may also be indirectly connected, for example, the electrode terminal and the tab are indirectly connected through a current collecting member.
  • the current collecting member may be a metal conductor, for example, copper, iron, aluminum, steel, aluminum alloy, etc.
  • two electrode terminals can be provided on the end cover 11 , and the two electrode terminals are respectively a positive electrode terminal 3 and a negative electrode terminal 4 , the positive electrode terminal 3 is electrically connected to the positive electrode ear 21 , and the negative electrode terminal 4 is electrically connected to the negative electrode ear 22 .
  • Figure 4 is a schematic diagram of the structure of the shell component 5 provided in some embodiments of the present application;
  • Figure 5 is a CC cross-sectional view of the shell component 5 shown in Figure 4;
  • Figure 6 is a grain map (schematic diagram) of the shell component 5 shown in Figure 5;
  • Figure 7 is a partial enlarged view of the E of the shell component 5 shown in Figure 5.
  • the embodiment of the present application provides a shell component 5 for a battery cell 10, including a non-weak area 51 and a weak area 52 formed in one piece, the shell component 5 is provided with a groove 53, the non-weak area 51 is formed around the groove 53, the weak area 52 is formed at the bottom of the groove 53, and the weak area 52 is configured to be destroyed when the battery cell 10 releases internal pressure.
  • the average grain size of the weak area 52 is S 1
  • the average grain size of the non-weak area 51 is S 2 , satisfying: S 1 /S 2 ⁇ 0.9.
  • the shell component 5 is a component that can accommodate the electrode assembly 2 together with other components.
  • the shell component 5 is a part of the shell 1.
  • the end cap 11 of the shell 1 can be the shell component 5, and the shell 12 of the shell 1 can be the shell component 5.
  • the shell component 5 can be made of metal, such as copper, iron, aluminum, steel, aluminum alloy, etc., and the shell component 5 can be an aluminum-plastic film.
  • the weak area 52 is a portion of the outer shell component 5 that is weaker than other areas.
  • the weak area 52 of the outer shell component 5 can be destroyed to release the pressure inside the battery cell 10.
  • the weak area 52 can be destroyed by rupture, detachment, etc.
  • the weak area 52 ruptures under the action of the emissions (gas, electrolyte, etc.) inside the battery cell 10, so that the emissions inside the battery cell 10 can be discharged smoothly.
  • the weak area 52 can be in a variety of shapes, such as rectangular, circular, elliptical, annular, arc-shaped, U-shaped, H-shaped, etc.
  • the thickness of the weak area 52 can be uniform or uneven.
  • the weak area 52 is formed at the bottom of the groove 53.
  • the groove 53 can be formed in a variety of ways.
  • the groove 53 can be formed by stamping, milling, laser etching, etc., so as to realize the integral molding of the weak area 52 and the non-weak area 51.
  • the shell component 5 is thinned in the area where the groove 53 is set, and the weak area 52 is formed accordingly.
  • the groove 53 can be a primary groove, and the groove side of the groove 53 is continuous along the depth direction of the groove 53.
  • the groove 53 is a groove whose internal space is a rectangular parallelepiped, a columnar body, etc.
  • the groove 53 can also be a multi-level groove, and the multi-level grooves are arranged along the depth direction of the groove 53.
  • the inner (deeper position) primary groove is set on the groove bottom surface of the outer (shallower position) primary groove.
  • the groove 53 is a stepped groove.
  • the multi-stage grooves can be formed by stamping step by step along the depth direction of the groove portion 53 , and the weak area 52 is formed at the bottom of the first-stage groove located at the deepest position (innermost) among the multi-stage grooves.
  • the non-weak area 51 is formed around the groove 53, and the strength of the non-weak area 51 is greater than that of the weak area 52.
  • the weak area 52 is more easily damaged than the non-weak area 51.
  • the non-weak area 51 can be a portion of the shell component 5 that is not stamped.
  • the thickness of the non-weak area 51 can be uniform or non-uniform.
  • the method for measuring the average grain size can refer to the intercept method in GB 6394-2017, which will not be described in detail here.
  • the measurement can be performed along the thickness direction of the weak area 52; when measuring the average grain size of the non-weak area 51, the measurement can be performed along the thickness direction of the non-weak area 51.
  • the thickness direction of the weak area 52 is consistent with the thickness direction of the non-weak area 51 , both of which are in the Z direction.
  • S 1 /S 2 can be any one of 0.01, 0.03, 0.04, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9 or a range between any two of them.
  • the weak area 52 and the non-weak area 51 are integrally formed, and the reliability of the housing component 5 is higher. Since S 1 /S 2 ⁇ 0.9, the average grain size of the weak area 52 is greatly different from the average grain size of the non-weak area 51, and the average grain size of the weak area 52 is reduced, so as to achieve the purpose of refining the grains of the weak area 52, improve the mechanical properties of the material of the weak area 52, improve the toughness and fatigue resistance of the weak area 52, reduce the risk of the weak area 52 being damaged under normal use conditions of the battery cell 10, and improve the service life of the battery cell 10.
  • S 1 /S 2 ⁇ 0.05.
  • the inventors have noticed that when S 1 /S 2 ⁇ 0.05, the difficulty of forming the weak area 52 increases, and the strength of the weak area 52 is too large, making it more difficult for the weak area 52 to be destroyed when the battery cell 10 thermally runs away, and the pressure relief is likely to be delayed.
  • S 1 /S 2 can be any one of 0.1, 0.12, 0.15, 0.17, 0.2, 0.22, 0.25, 0.27, 0.3, 0.32, 0.35, 0.37, 0.4, 0.42, 0.45, 0.47, 0.5, or a range between any two of them.
  • 0.1 ⁇ S 1 /S 2 ⁇ 0.5 so that the overall performance of the housing component 5 is better, and the weak area 52 can be destroyed in time when the battery cell 10 is in thermal runaway, and the weak area 52 has sufficient strength under normal use conditions of the battery cell 10.
  • S 1 can be any point value among 0.4 ⁇ m, 0.5 ⁇ m, 1 ⁇ m, 2 ⁇ m, 3 ⁇ m, 4 ⁇ m, 5 ⁇ m, 10 ⁇ m, 15 ⁇ m, 20 ⁇ m, 25 ⁇ m, 28 ⁇ m, 30 ⁇ m, 35 ⁇ m, 36 ⁇ m, 40 ⁇ m, 45 ⁇ m, 49 ⁇ m, 50 ⁇ m, 55 ⁇ m, 60 ⁇ m, 65 ⁇ m, 70 ⁇ m, 72 ⁇ m, 75 ⁇ m, or any range value between any two of them.
  • 0.1 ⁇ m ⁇ S 1 ⁇ 75 ⁇ m reduces the difficulty of forming the weak area 52 and improves the timeliness of pressure relief of the battery cell 10 during thermal runaway; on the other hand, improves the toughness and fatigue resistance of the weak area 52 and reduces the risk of the weak area 52 being damaged under normal use conditions of the battery cell 10.
  • S 1 can be any point value among 1 ⁇ m, 1.5 ⁇ m, 1.6 ⁇ m, 2 ⁇ m, 2.5 ⁇ m, 2.6 ⁇ m, 3 ⁇ m, 3.5 ⁇ m, 3.6 ⁇ m, 4 ⁇ m, 4.5 ⁇ m, 4.6 ⁇ m, 5 ⁇ m, 5.5 ⁇ m, 5.6 ⁇ m, 6 ⁇ m, 6.5 ⁇ m, 6.6 ⁇ m, 7 ⁇ m, 7.5 ⁇ m, 7.6 ⁇ m, 8 ⁇ m, 8.5 ⁇ m, 8.6 ⁇ m, 9 ⁇ m, 9.5 ⁇ m, 9.6 ⁇ m, 10 ⁇ m, or any range value between any two of them.
  • S 2 can be any point value among 10 ⁇ m, 15 ⁇ m, 20 ⁇ m, 25 ⁇ m, 30 ⁇ m, 35 ⁇ m, 40 ⁇ m, 45 ⁇ m, 50 ⁇ m, 55 ⁇ m, 60 ⁇ m, 65 ⁇ m, 70 ⁇ m, 75 ⁇ m, 80 ⁇ m, 85 ⁇ m, 90 ⁇ m, 95 ⁇ m, 100 ⁇ m, 105 ⁇ m, 110 ⁇ m, 115 ⁇ m, 120 ⁇ m, 125 ⁇ m, 130 ⁇ m, 135 ⁇ m, 140 ⁇ m, 145 ⁇ m, 150 ⁇ m, or any range value between any two of them.
  • S 2 can be any point value among 30 ⁇ m, 32 ⁇ m, 35 ⁇ m, 37 ⁇ m, 40 ⁇ m, 42 ⁇ m, 45 ⁇ m, 47 ⁇ m, 50 ⁇ m, 52 ⁇ m, 55 ⁇ m, 57 ⁇ m, 60 ⁇ m, 62 ⁇ m, 65 ⁇ m, 67 ⁇ m, 70 ⁇ m, 72 ⁇ m, 75 ⁇ m, 77 ⁇ m, 80 ⁇ m, 82 ⁇ m, 85 ⁇ m, 87 ⁇ m, 90 ⁇ m, 92 ⁇ m, 95 ⁇ m, 97 ⁇ m, 100 ⁇ m, or any range value between any two of them.
  • the minimum thickness of the weak area 52 is A, satisfying: 1 ⁇ A/S 1 ⁇ 100.
  • A/S 1 can be any point value among 1, 2, 4, 5, 10, 15, 20, 21, 22, 23, 25, 30, 33, 34, 35, 37, 38, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 93, 94, 95, 100 or any range between two of them.
  • A/S 1 can be any one of 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20 or a range between any two of them.
  • the minimum thickness of the weak area 52 is A, and the hardness of the weak area 52 is H 1 , satisfying: 5HBW/mm ⁇ H 1 /A ⁇ 10000HBW/mm.
  • H 1 /A may be any one of 5HBW/mm, 6HBW/mm, 7HBW/mm, 20HBW/mm, 50HBW/mm, 61HBW/mm, 62HBW/mm, 63HBW/mm, 64HBW/mm, 75HBW/mm, 90HBW/mm, 100HBW/mm, 120HBW/mm, 150HBW/mm, 190HBW/mm, 500HBW/mm, 1000HBW/mm, 1200HBW/mm, 1750HBW/mm, 1800HBW/mm, 2100HBW/mm, 4000HBW/mm, 5000HBW/mm, 8000HBW/mm, 9000HBW/mm, and 10000HBW/mm, or a range between any two of them.
  • the hardness of the weak area 52 is the Brinell hardness, and the unit is HBW.
  • the Brinell hardness measurement method can be implemented by referring to the measurement principle in GB/T 23.1-2018. In the actual measurement process, the hardness of the weak area 52 can be measured on the inner surface or outer surface in the thickness direction of the weak area 52. Taking the shell component 5 as the end cover 11 of the battery cell 10 as an example, the hardness of the weak area 52 can be measured on the outer surface of the weak area 52 away from the inside of the battery cell 10, and the hardness of the weak area 52 can also be measured on the inner surface of the weak area 52 facing the inside of the battery cell 10.
  • the weak area 52 When H 1 /A>10000HBW/mm, the weak area 52 is thinner and has a higher hardness, which makes the weak area 52 very thin and brittle, and the weak area 52 is easily damaged under normal use conditions of the battery cell 10, and the service life of the battery cell 10 is short.
  • H 1 /A ⁇ 5HBW/mm the weak area 52 is thicker and has a lower hardness. When the battery cell 10 thermally runs away, the weak area 52 will be stretched and extended, and the timeliness of pressure relief is poor.
  • the influence of the thickness of the weak area 52 on the performance of the shell component 5 is taken into consideration, but also the influence of the hardness of the weak area 52 on the performance of the shell component 5 is taken into consideration, 5HBW/mm ⁇ H 1 /A ⁇ 10000HBW/mm, which can not only ensure that the weak area 52 has sufficient strength under normal use conditions of the battery cell 10, and the weak area 52 is not easily damaged due to fatigue, thereby improving the service life of the battery cell 10; and can also enable the shell component 5 to release pressure in time through the weak area 52 when the battery cell 10 is thermally runaway, thereby reducing the risk of explosion of the battery cell 10 and improving the safety of the battery cell 10.
  • H 1 /A may be any one of 190 HBW/mm, 250 HBW/mm, 280 HBW/mm, 300 HBW/mm, 350 HBW/mm, 400 HBW/mm, 450 HBW/mm, 500 HBW/mm, 600 HBW/mm, 700 HBW/mm, 875 HBW/mm, 1000 HBW/mm, 1200 HBW/mm, 1500 HBW/mm, 1750 HBW/mm, 1800 HBW/mm, 2000 HBW/mm, 2100 HBW/mm, 2500 HBW/mm, 3000 HBW/mm, 3500 HBW/mm, and 4000 HBW/mm, or a range between any two of them.
  • 190HBW/mm ⁇ H 1 /A ⁇ 4000HBW/mm so that the overall performance of the housing component 5 is better, and the weak area 52 can be destroyed in time when the battery cell 10 is in thermal runaway, and the weak area 52 has sufficient strength under normal use conditions of the battery cell 10. Under the premise of ensuring the safety of the battery cell 10, the service life of the battery cell 10 is improved.
  • A can be any point value among 0.02mm, 0.04mm, 0.05mm, 0.06mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 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, 1.42mm, 1.43mm, 1.45mm, 1.47mm, 1.5mm, 1.55mm, 1.6mm, or any range value between any two of them.
  • the weak area 52 When A is less than 0.02 mm, the weak area 52 is difficult to form, and the weak area 52 is easily damaged during the forming process; when A is greater than 1.6 mm, the weak area 52 is more difficult to be destroyed when the battery cell 10 has thermal runaway, and the pressure relief is likely to be untimely.
  • A can be any point value among 0.06mm, 0.07mm, 0.08mm, 0.1mm, 0.15mm, 0.18mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, or a range value between any two of them.
  • 0.06 mm ⁇ A ⁇ 0.4 mm 0.06 mm ⁇ A ⁇ 0.4 mm, which further reduces the difficulty of forming the weak area 52 and improves the timeliness of pressure relief of the battery cell 10 during thermal runaway.
  • the hardness of the weak region 52 is H 1
  • the hardness of the non-weak region 51 is H 2 , satisfying: H 1 >H 2 .
  • the hardness of the non-weak area 51 is the Brinell hardness, and the unit is HBW. In the actual measurement process, the hardness of the non-weak area 51 can be measured on the inner surface or outer surface of the non-weak area 51 in the thickness direction. Taking the shell component 5 as the end cover 11 of the battery cell 10 as an example, the hardness of the non-weak area 51 can be measured on the outer surface of the non-weak area 51 away from the inside of the battery cell 10, and the hardness of the non-weak area 51 can also be measured on the inner surface of the non-weak area 51 facing the inside of the battery cell 10.
  • H 1 >H 2 , which is equivalent to increasing the hardness of the weak area 52 , thereby increasing the strength of the weak area 52 and reducing the risk of the weak area 52 being damaged under normal use conditions of the battery cell 10 .
  • H 1 /H 2 ⁇ 5.
  • H 1 /H 2 can be any one of 1.1, 1.5, 2, 2.5, 3, 3.5, 3.6, 4, 4.5, 5, or a range of values between any two of them.
  • the hardness of the weak area 52 may be too large, and the weak area 52 may be difficult to be destroyed when the battery cell 10 thermally runs away.
  • H 1 /H 2 ⁇ 5 which reduces the risk that the weak area 52 cannot be destroyed in time when the battery cell 10 is in thermal runaway, thereby improving the safety of the battery cell 10 .
  • H 1 /H 2 ⁇ 2.5.
  • H 1 /H 2 can be any one of 1.1, 1.11, 1.12, 1.2, 1.25, 1.3, 1.4, 1.5, 1.6, 1.7, 1.71, 1.72, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5 or a range between any two of them.
  • H 1 /H 2 ⁇ 2.5 which can further reduce the risk that the weak area 52 cannot be destroyed in time when the battery cell 10 has thermal runaway.
  • H2 can be any one of 5HBW, 8HBW, 9HBW, 9.5HBW, 10HBW, 15HBW, 16HBW, 19HBW, 20HBW, 30HBW, 40HBW, 50HBW, 52HBW, 52.5HBW, 53HBW, 60HBW, 70HBW, 80HBW, 90HBW, 100HBW, 110HBW, 120HBW, 130HBW, 140HBW, and 150HBW, or a range between any two of them.
  • H1 can be any one of 5HBW, 6HBW, 8HBW, 10HBW, 15HBW, 19HBW, 20HBW, 30HBW, 50HBW, 60HBW, 70HBW, 80HBW, 90HBW, 100HBW, 110HBW, 120HBW, 130HBW, 140HBW, 150HBW, 160HBW, 170HBW, 180HBW, 190HBW, and 200HBW, or a range between any two of them.
  • Figure 7 and Figure 8 is a partial enlarged view of the housing component 5 provided in some other embodiments of the present application.
  • the minimum thickness of the weak area 52 is A
  • the minimum thickness of the non-weak area 51 is B, satisfying: 0.05 ⁇ A/B ⁇ 0.95.
  • the minimum thickness of the weak area 52 is the thickness at the thinnest position of the weak area 52.
  • the minimum thickness of the non-weak area 51 is the thickness at the thinnest position of the non-weak area 51.
  • the shell component 5 has a first surface 54 and a second surface 55 that are arranged opposite to each other.
  • the groove 53 is recessed from the first surface 54 toward the second surface 55.
  • the portion of the shell component 5 located between the groove bottom surface 531 and the second surface 55 is a weak area 52.
  • the first surface 54 and the second surface 55 can be arranged in parallel or at a small angle. If the first surface 54 and the second surface 55 are arranged at a small angle, for example, the angle between the two is within 10 degrees, the minimum distance between the first surface 54 and the second surface 55 is the minimum thickness of the non-weak area 51; as shown in Figures 7 and 8, if the first surface 54 and the second surface 55 are parallel, the distance between the first surface 54 and the second surface 55 is the minimum thickness of the non-weak area 51.
  • the groove bottom surface 531 of the groove portion can be a plane or a curved surface. If the groove bottom surface 531 of the groove portion is a plane, the groove bottom surface 531 of the groove portion and the second surface 55 can be parallel or set at a small angle. If the groove bottom surface 531 of the groove portion and the second surface 55 are set at a small angle, for example, the angle between the two is within 10 degrees, the minimum distance between the groove bottom surface 531 of the groove portion and the second surface 55 is the minimum thickness of the weak area 52; as shown in FIG7, if the groove bottom surface 531 of the groove portion is parallel to the second surface 55, the distance between the groove bottom surface 531 of the groove portion and the second surface 55 is the minimum thickness of the weak area 52.
  • the minimum distance between the groove bottom surface 531 of the groove portion and the second surface 55 is the minimum thickness of the weak area 52.
  • A/B can be any point value among 0.05, 0.06, 0.07, 0.08, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.8, 0.85, 0.9, 0.95 or any range between two of them.
  • the weak area 52 When A/B ⁇ 0.05, the weak area 52 may be insufficient in strength, and the probability of the weak area 52 rupturing under normal use conditions of the battery cell 10 increases. When A/B>0.95, the weak area 52 may not be easily destroyed when the battery cell 10 is in thermal runaway, and the pressure relief is not timely, resulting in an increased probability of the battery cell 10 exploding. Therefore, 0.05 ⁇ A/B ⁇ 0.95 can reduce the probability of the weak area 52 rupturing under normal use conditions of the battery cell 10, and can also reduce the probability of the battery cell 10 exploding when it is in thermal runaway.
  • A/B can be any one of 0.12, 0.13, 0.14, 0.15, 0.17, 0.2, 0.22, 0.25, 0.27, 0.3, 0.32, 0.35, 0.37, 0.4, 0.42, 0.45, 0.47, 0.5, 0.52, 0.55, 0.57, 0.6, 0.62, 0.65, 0.66, 0.67, 0.7, 0.72, 0.75, 0.77, 0.8 or any range between two of them.
  • A/B can be any one of 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, or a range between any two of them.
  • A/B is controlled between 0.2 and 0.5, which further reduces the risk of the weak area 52 being damaged under normal use conditions of the battery cell 10 and ensures that the weak area 52 is damaged in time when the battery cell 10 has thermal runaway, thereby improving the timeliness of pressure relief.
  • B can be any point value among 1mm, 2mm, 3mm, 4mm, 5mm, or a range value between any two of them.
  • B can be any point value among 1.2mm, 1.25mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, or a range value between any two of them.
  • FIG9 is a schematic diagram of the structure of the shell component 5 provided in some other embodiments of the present application (showing the primary notch groove 532);
  • FIG10 is an E-E cross-sectional view of the shell component 5 shown in FIG9;
  • FIG11 is a schematic diagram of the structure of the shell component 5 provided in some other embodiments of the present application (showing the primary notch groove 532);
  • FIG12 is an F-F cross-sectional view of the shell component 5 shown in FIG11;
  • FIG13 is a schematic diagram of the structure of the shell component 5 provided in some other embodiments of the present application (showing the primary notch groove 532);
  • FIG14 is a G-G cross-sectional view of the shell component 5 shown in FIG13.
  • the shell component 5 has a pressure relief area 56, and the groove portion 53 includes a primary notch groove 532, and the notch groove 532 is arranged along the edge of the pressure relief area 56, and the pressure relief area 56 is configured to be able to be opened with the notch groove 532 as the boundary, and the weak area 52 forms the bottom of the notch groove 532.
  • the pressure relief area 56 is an area of the outer shell component 5 that can be opened after the weak area 52 is damaged. For example, when the pressure inside the battery cell 10 reaches a threshold, the weak area 52 is cracked, and the pressure relief area 56 is opened outward under the action of the discharge inside the battery cell 10. In this process, the weak area 52 is cracked along the notched groove 532, and the pressure relief area 56 is opened, so that the pressure relief area 56 is opened with the notched groove 532 as the boundary. After the pressure relief area 56 is opened, the outer shell component 5 can form a discharge port at a position corresponding to the pressure relief area 56, and the discharge inside the battery cell 10 can be discharged through the discharge port to release the pressure inside the battery cell 10.
  • the notched groove 532 can be formed in the housing component 5 in a variety of ways, such as stamping, milling, laser etching, etc.
  • the notched groove 532 in the groove portion 53 is only one level, and the first-level notched groove 532 can be formed by one stamping.
  • the notched groove 532 can be a groove of various shapes, such as an annular groove, an arc groove, a U-shaped groove, an H-shaped groove, etc.
  • the weak area 52 is formed at the bottom of the notched groove 532, and the shape of the weak area 52 is the same as the shape of the notched groove 532.
  • the weak area 52 is a U-shaped groove, and the weak area 52 extends along the U-shaped track.
  • the maximum width of the notch groove 532 is X, where X ⁇ 10 mm.
  • the width of the notch groove 532 at its widest position is the maximum width of the notch groove 532 .
  • the weak area 52 forms the bottom of the notch groove 532 .
  • the pressure relief area 56 can be opened with the weak area 52 as the boundary to achieve pressure relief, thereby increasing the pressure relief area of the shell component 5 .
  • the housing component 5 has a first surface 54 and a second surface 55 that are oppositely disposed, and the notched groove 532 is recessed from the first surface 54 toward the direction close to the second surface 55 .
  • the first surface 54 may be the inner surface of the shell component 5 facing the inside of the battery cell 10, and the second surface 55 may be the outer surface of the shell component 5 away from the inside of the battery cell 10; or the first surface 54 may be the outer surface of the shell component 5 away from the inside of the battery cell 10, and the second surface 55 may be the inner surface of the shell component 5 facing the inside of the battery cell 10.
  • the first surface 54 is parallel to the second surface 55, and the minimum thickness of the non-weak area 51 is the distance between the first surface 54 and the second surface 55.
  • the groove bottom surface of the notched groove 532 is the groove bottom surface 531 of the groove portion.
  • the portion of the housing component 5 between the groove bottom surface of the notched groove 532 and the second surface 55 is the groove bottom wall of the notched groove 532, and the groove bottom wall of the notched groove 532 is the weak area 52.
  • the groove portion 53 only includes a primary notch groove 532, and the notch groove 532 is the groove portion 53.
  • the groove portion 53 is a primary groove with a simple structure.
  • the notch groove 532 can be molded on the first surface 54, which is simple to mold, improves production efficiency, and reduces production costs.
  • Figure 15 is a schematic structural diagram of a shell component 5 provided in some other embodiments of the present application (showing a two-stage notch groove 532);
  • Figure 16 is a K-K cross-sectional view of the shell component 5 shown in Figure 15;
  • Figure 17 is a schematic structural diagram of a shell component 5 provided in some other embodiments of the present application (showing a two-stage notch groove 532);
  • Figure 18 is an M-M cross-sectional view of the shell component 5 shown in Figure 17;
  • Figure 19 is a schematic structural diagram of a shell component 5 provided in some other embodiments of the present application (showing a two-stage notch groove 532);
  • Figure 20 is an N-N cross-sectional view of the shell component 5 shown in Figure 19.
  • the shell component 5 includes a first surface 54 and a second surface 55 arranged oppositely, and the groove portion 53 includes a multi-stage notch groove 532, which is sequentially arranged on the shell component 5 along the direction from the first surface 54 to the second surface 55, and the weak area 52 is formed at the bottom of the first-stage notch groove 532 farthest from the first surface 54.
  • the housing component 5 has a pressure relief zone 56 , each level of notched groove 532 is arranged along the edge of the pressure relief zone 56 , and the pressure relief zone 56 is configured to be able to open with the first level notched groove 532 farthest from the first surface 54 as a boundary.
  • the groove portion 53 includes a multi-stage notched groove 532. It is understandable that the groove portion 53 is a multi-stage groove. Each stage of the notched groove 532 is arranged along the edge of the pressure relief zone 56. It is understandable that the multi-stage notched groove 532 is arranged around the pressure relief zone 56, so that the extension direction of the multi-stage notched groove 532 is basically the same, so that the shape of the multi-stage notched groove 532 is basically the same.
  • the notched groove 532 in the groove portion 53 can be two-stage, three-stage, four-stage or more. Each stage of the notched groove 532 can be formed on the shell component 5 by stamping.
  • the notched groove 532 of each stage can be stamped and formed in sequence along the direction from the first surface 54 to the second surface 55.
  • the multi-stage notched groove 532 can be formed by multiple stampings, and each stamping forms a stage of notched groove 532.
  • the notched groove 532 can be a groove of various shapes, such as an annular groove, an arc groove, a U-shaped groove, an H-shaped groove, etc.
  • the pressure relief area 56 is an area of the housing component 5 that can be opened after the weak area 52 is damaged.
  • the primary notch 532 farthest from the first surface 54 is located at the edge of the pressure relief area 56.
  • the weak area 52 is split along the primary notch 532 farthest from the first surface 54, so that the pressure relief area 56 is opened with the primary notch 532 farthest from the first surface 54 as the boundary.
  • the weak area 52 is formed at the bottom of the primary notch groove 532 farthest from the first surface 54, and the primary notch groove 532 farthest from the first surface 54 is the primary notch groove 532 at the deepest position (innermost).
  • the primary notch groove 532 farthest from the first surface 54 is arranged at the bottom surface of the primary notch groove 532 close to the first surface 54.
  • the portion of the housing component 5 between the groove bottom surface of the primary notch groove 532 farthest from the first surface 54 and the second surface 55 is the groove bottom wall of the primary notch groove 532 farthest from the first surface 54, and the groove bottom wall is the weak area 52.
  • the groove bottom surface of the primary notch groove 532 farthest from the first surface 54 is the groove bottom surface 531 of the groove portion.
  • the primary scoring groove 532 farthest from the first surface 54 is the innermost primary scoring groove 532b, and the primary scoring groove 532 closest to the first surface 54 is the outermost primary scoring groove 532a.
  • the maximum width of the outermost primary notch groove 532a is X, where X ⁇ 10 mm.
  • the width of the outermost primary notch groove 532a at the widest position is the maximum width of the outermost primary notch groove 532a.
  • multiple levels of notched grooves 532 can be formed step by step on the shell component 5, and the molding depth of each level of notched groove 532 can be reduced, thereby reducing the molding force applied to the shell component 5 when molding each level of notched groove 532, reducing the risk of cracks in the shell component 5, and making it less likely for the shell component 5 to fail due to cracks at the location where the notched groove 532 is set, thereby increasing the service life of the shell component 5.
  • the primary notch groove 532 farthest from the second surface 55 is recessed from the first surface 54 toward the direction close to the second surface 55 .
  • the two-level notched groove 532 is a first-level notched groove and a second-level notched groove.
  • the first-level notched groove is arranged on the first surface 54, that is, the first-level notched groove is recessed from the first surface 54 toward the direction close to the second surface 55
  • the second-level notched groove is arranged on the groove bottom surface of the first-level notched groove; that is, the second-level notched groove is recessed from the groove bottom surface of the first-level notched groove toward the direction close to the second surface 55.
  • the first-level notched groove is the outermost first-level notched groove 532a
  • the second-level notched groove is the innermost first-level notched groove 532b.
  • the groove portion 53 is composed of a multi-stage notched groove 532 .
  • the multi-stage notched groove 532 can be gradually machined from the first surface 54 to the second surface 55 , and the molding efficiency is high.
  • Figure 21 is an isometric view of the housing component 5 provided in some embodiments of the present application
  • Figure 22 is a structural schematic diagram of the housing component 5 shown in Figure 21 (showing the primary notch groove 532 and the primary sink groove 533);
  • Figure 23 is an O-O cross-sectional view of the housing component 5 shown in Figure 22
  • Figure 24 is a structural schematic diagram of the housing component 5 provided in some other embodiments of the present application (showing the primary notch groove 532 and the primary sink groove 533);
  • Figure 25 is a P-P cross-sectional view of the housing component 5 shown in Figure 24
  • Figure 26 is a structural schematic diagram of the housing component 5 provided in some other embodiments of the present application (showing the primary notch groove 532 and the primary sink groove 533);
  • Figure 27 is a Q-Q cross-sectional view of the housing component 5 shown in Figure 26.
  • the housing component 5 includes a first surface 54 and a second surface 55 arranged opposite to each other, and the groove portion 53 also includes a primary sink groove 533, the sink groove 533 is recessed from the first surface 54 to the direction close to the second surface 55, and the pressure relief area 56 is formed on the bottom wall 5331 of the sink groove.
  • the groove portion 53 may include a one-stage sink groove 533. It is understandable that the groove portion 53 has both the notched groove 532 and the sink groove 533, and the groove portion 53 is a multi-stage groove.
  • the sink groove 533 and the notched groove 532 are arranged along the direction from the first surface 54 to the second surface 55.
  • the sink groove 533 can be molded on the shell component 5 first, and then the notched groove 532 can be molded on the bottom wall 5331 of the sink groove.
  • the sink groove 533 can be molded on the shell component 5 in a variety of ways, such as stamping molding, milling molding, laser etching molding, etc.
  • the bottom wall 5331 of the sink is the portion of the housing component 5 located below the bottom surface of the sink 533. After the sink 533 is formed on the first surface 54, the remaining portion of the housing component 5 in the area where the sink 533 is set is the bottom wall 5331 of the sink. As shown in Figures 23, 25, and 27, the portion of the housing component 5 located between the bottom surface of the sink 533 and the second surface 55 is the bottom wall 5331 of the sink.
  • the pressure relief area 56 may be a portion of the bottom wall 5331 of the sink.
  • the arrangement of the recessed groove 533 can reduce the depth of the notched groove 532 while ensuring that the thickness of the final weak area 52 is constant, thereby reducing the forming force on the shell component 5 when forming the notched groove 532, and reducing the risk of cracks in the shell component 5.
  • the recessed groove 533 can provide an escape space for the pressure relief area 56 during the opening process, and even if the first surface 54 is blocked by an obstacle, the pressure relief area 56 can still be opened to relieve pressure.
  • Figure 28 is a structural schematic diagram of the shell component 5 provided in some embodiments of the present application (showing the primary notch groove 532 and the two-stage sink groove 533);
  • Figure 29 is an R-R cross-sectional view of the shell component 5 shown in Figure 28;
  • Figure 30 is a structural schematic diagram of the shell component 5 provided in some other embodiments of the present application (showing the primary notch groove 532 and the two-stage sink groove 533);
  • Figure 31 is an S-S cross-sectional view of the shell component 5 shown in Figure 30;
  • Figure 32 is a structural schematic diagram of the shell component 5 provided in other embodiments of the present application (showing the primary notch groove 532 and the two-stage sink groove 533);
  • Figure 33 is a T-T cross-sectional view of the shell component 5 shown in Figure 32.
  • the shell component 5 includes a first surface 54 and a second surface 55 that are arranged opposite to each other, and the groove portion 53 also includes a multi-stage groove 533.
  • the multi-stage groove 533 is sequentially arranged on the shell component 5 along the direction from the first surface 54 to the second surface 55.
  • the first-stage groove 533 farthest from the second surface 55 is recessed from the first surface 54 to the second surface 55, and the pressure relief area 56 is formed on the groove bottom wall 5331 of the first-stage groove farthest from the first surface 54.
  • the groove portion 53 may include multi-stage sink grooves 533. It is understandable that the groove portion 53 has both the notched groove 532 and the sink groove 533, and the groove portion 53 is a multi-stage groove.
  • the sink groove 533 and the notched groove 532 are arranged along the direction from the first surface 54 to the second surface 55.
  • the multi-stage sink groove 533 may be molded on the housing component 5 first, and then the notched groove 532 may be molded on the groove bottom wall 5331 of the first-stage sink groove farthest from the first surface 54.
  • the first-level sink groove 533 farthest from the second surface 55 is the outermost first-level sink groove 533a
  • the first-level sink groove 533 farthest from the first surface 54 is the innermost first-level sink groove 533b.
  • the outermost first-level sink groove 533a is disposed on the first surface 54
  • the outermost first-level sink groove 533a is recessed from the first surface 54 to the second surface 55.
  • the groove bottom wall 5331 of the primary groove farthest from the first surface 54 is the portion of the shell component 5 below the groove bottom surface of the primary groove 533 farthest from the first surface 54.
  • the remaining portion of the shell component 5 in the area where the primary groove 533 farthest from the first surface 54 is set is the groove bottom wall 5331 of the groove.
  • the portion of the shell component 5 between the groove bottom surface of the primary groove 533 farthest from the first surface 54 and the second surface 55 is the groove bottom wall 5331 of the primary groove farthest from the first surface 54.
  • the pressure relief area 56 can be a part of the groove bottom wall 5331 of the primary groove farthest from the first surface 54.
  • the sink grooves 533 in the groove portion 53 may be two-level, three-level, four-level or more.
  • the first-level sink groove 533 away from the first surface 54 is arranged on the bottom surface of the first-level sink groove 533 close to the first surface 54.
  • the contour of the bottom surface of the multi-level sink groove 533 decreases step by step.
  • the sink grooves 533 of each level can be formed on the shell component 5 in a variety of ways, such as stamping, milling, laser etching, etc.
  • the sink grooves 533 of each level can be stamped out in sequence along the direction from the first surface 54 to the second surface 55, and then the notched grooves 532 can be stamped.
  • the groove 533 in the groove portion 53 is two-stage and the notched groove 532 is one-stage as an example
  • two stampings may be performed first to form two-stage grooves 533, and then one stamping may be performed to form one-stage notched groove 532.
  • the groove 533 in the groove portion 53 is two-stage.
  • the multi-stage groove 533 When forming the multi-stage groove 533, the forming depth of each stage of the groove 533 can be reduced, and the forming force applied to the shell component 5 when forming each stage of the groove 533 can be reduced, thereby reducing the risk of cracks in the shell component 5.
  • the multi-stage groove 533 can provide an escape space for the pressure relief zone 56 during the opening process, so that even if the first surface 54 is blocked by an obstacle, the pressure relief zone 56 can still be opened to relieve pressure.
  • the internal space of the sink 533 is a cylinder, a prism, a frustum or a prism.
  • the internal space of the sink 533 is the space defined by the side surface and the bottom surface of the sink 533.
  • the prism body can be a triangular prism, a quadrangular prism, a pentagonal prism, a hexagonal prism, etc.; the pyramid body can be a triangular pyramid, a quadrangular pyramid, a pentagonal pyramid, or a hexagonal pyramid, etc.
  • the internal space of the groove 53 is a quadrangular prism, and specifically, the internal space of the groove 53 is a cuboid.
  • the sink 533 has a simple structure and is easy to form, and can provide more avoidance space for the pressure relief area 56 during the opening process.
  • FIG. 34 is a schematic diagram of the structure of the housing component 5 provided in some embodiments of the present application (showing a primary notch groove 532 , which is V-shaped).
  • the notch groove 532 includes a first groove section 5321 and a second groove section 5322 , the first groove section 5321 intersects with the second groove section 5322 , and the first groove section 5321 and the second groove section 5322 are arranged along the edge of the pressure relief area 56 .
  • the first slot section 5321 and the second slot section 5322 may be straight slots or non-straight slots, such as arc slots. In the embodiment where the first slot section 5321 and the second slot section 5322 are both straight slots, it is understandable that the first slot section 5321 and the second slot section 5322 both extend along a straight line, and the first slot section 5321 and the second slot section 5322 may be arranged at an acute angle, a right angle or an obtuse angle.
  • the first slot section 5321 and the second slot section 5322 may be arranged crosswise, such as the intersection of the first slot section 5321 and the second slot section 5322 is located at the midpoint of the first slot section 5321 and the midpoint of the second slot section 5322; as shown in FIG.
  • the intersection of the first slot section 5321 and the second slot section 5322 may also be located at one end of the first slot section 5321 and one end of the second slot section 5322, the first slot section 5321 and the second slot section 5322 constitute a V-shaped structure, and the notched groove 532 is V-shaped.
  • the stress at the intersection of the first groove section 5321 and the second groove section 5322 is more concentrated, so that the weak area 52 can be first destroyed at the intersection of the first groove section 5321 and the second groove section 5322.
  • the weak area 52 can be made thicker to reduce the molding depth of the notch groove 532.
  • the notched groove 532 can also include a third groove section 5323, the first groove section 5321 and the third groove section 5323 are arranged opposite to each other, the second groove section 5322 intersects with the third groove section 5323, and the first groove section 5321, the second groove section 5322 and the third groove section 5323 are arranged along the edge of the pressure relief zone 56.
  • the first slot section 5321, the second slot section 5322 and the third slot section 5323 can all be straight slots, or non-straight slots, such as arc slots.
  • first slot section 5321, the second slot section 5322 and the third slot section 5323 are all straight slots, it is understandable that the first slot section 5321, the second slot section 5322 and the third slot section 5323 all extend along a straight line, and the first slot section 5321 and the third slot section 5323 can be arranged in parallel, or they can be arranged at an angle.
  • the first slot section 5321 and the third slot section 5323 can be perpendicular to the second slot section 5322, or they can be non-perpendicular to the second slot section 5322.
  • connection position between the second slot segment 5322 and the first slot segment 5321 can be located at one end of the first slot segment 5321, or at a position deviated from one end of the first slot segment 5321, for example, the connection position between the second slot segment 5322 and the first slot segment 5321 is located at the midpoint of the first slot segment 5321 in the extension direction; the connection position between the second slot segment 5322 and the third slot segment 5323 can be located at one end of the third slot segment 5323, or at a position deviated from one end of the third slot segment 5323, for example, the connection position between the second slot segment 5322 and the third slot segment 5323 is located at the midpoint of the third slot segment 5323 in the extension direction.
  • the groove portion 53 includes a multi-level notched groove 532
  • the first groove section 5321 of the first-level notched groove 532 away from the first surface 54 is arranged at the groove bottom surface of the first groove section 5321 of the first-level notched groove 532 close to the first surface 54
  • the second groove section 5322 of the first-level notched groove 532 away from the first surface 54 is arranged at the groove bottom surface of the second groove section 5322 of the first-level notched groove 532 close to the first surface 54
  • the third groove section 5323 of the first-level notched groove 532 away from the first surface 54 is arranged at the groove bottom surface of the third groove section 5323 of the first-level notched groove 532 close to the first surface 54.
  • the pressure relief zone 56 can be opened with the first groove section 5321 , the second groove section 5322 and the third groove section 5323 as boundaries.
  • the pressure relief zone 56 is opened more easily, thereby achieving large-area pressure relief of the housing component 5 .
  • the first slot segment 5321, the second slot segment 5322 and the third slot segment 5323 define two pressure relief areas 56, and the two pressure relief areas 56 are respectively located on both sides of the second slot segment 5322.
  • the first slot section 5321, the second slot section 5322 and the third slot section 5323 form an H-shaped notched slot 532
  • the connection position of the second slot section 5322 and the first slot section 5321 is located at the midpoint of the first slot section 5321
  • the connection position of the third slot section 5323 and the second slot section 5322 is located at the midpoint of the third slot section 5323.
  • the two pressure relief areas 56 are symmetrically arranged on both sides of the second slot section 5322, and it can be understood that the areas of the two pressure relief areas 56 are equal.
  • the two pressure relief zones 56 may also be asymmetrically arranged on both sides of the second slot section 5322, so that the areas of the two pressure relief zones 56 are not equal.
  • first slot section 5321 and the third slot section 5323 are both perpendicular to the second slot section 5322, the connection position between the second slot section 5322 and the first slot section 5321 deviates from the midpoint of the first slot section 5321, and/or the connection position between the third slot section 5323 and the second slot section 5322 is located at the midpoint of the third slot section 5323.
  • the two pressure relief zones 56 are respectively located on both sides of the second groove section 5322, so that the two pressure relief zones 56 are divided by the second groove section 5322. After the shell component 5 is ruptured at the position of the second groove section 5322, the two pressure relief zones 56 can be opened in a split form along the first groove section 5321 and the third groove section 5323 to achieve pressure relief, which can effectively improve the pressure relief efficiency of the shell component 5.
  • first slot segment 5321 , the second slot segment 5322 , and the third slot segment 5323 are connected in sequence, and the first slot segment 5321 , the second slot segment 5322 , and the third slot segment 5323 define a pressure relief zone 56 .
  • the first groove section 5321 , the second groove section 5322 and the third groove section 5323 are sequentially connected to form a U-shaped notched groove 532 .
  • the score groove 532 is a groove extending along a non-closed trajectory.
  • a non-closed track refers to a track whose two ends are not connected in the extension direction.
  • the non-closed track can be an arc track, a U-shaped track, etc.
  • the notched groove 532 is a groove along a non-closed trajectory, and the pressure relief area 56 can be opened in a flipping manner. After the pressure relief area 56 is opened, it is finally connected to other areas of the shell component 5, reducing the risk of splashing after the pressure relief area 56 is opened.
  • the notched groove 532 is an arc-shaped groove.
  • the arc-shaped groove is a groove extending along an arc-shaped trajectory, and the arc-shaped trajectory is a non-closed trajectory.
  • the center angle of the arc-shaped groove can be less than, equal to or greater than 180°.
  • the arc-shaped groove has a simple structure and is easy to form. During the pressure relief process, the pressure relief area 56 can be quickly broken along the arc-shaped groove so that the pressure relief area 56 is quickly opened.
  • the notched groove 532 is a groove extending along a closed track.
  • a closed trajectory refers to a trajectory that is connected at both ends.
  • a closed trajectory can be a circular trajectory, a rectangular trajectory, etc.
  • the shell component 5 can rupture along the notched groove 532 , so that the pressure relief area 56 can be opened in a detached manner, thereby increasing the pressure relief area of the shell component 5 and improving the pressure relief rate of the shell component 5 .
  • the score groove 532 is an annular groove.
  • the annular groove may be a rectangular annular groove or a circular annular groove.
  • the annular groove has a simple structure and is easy to form. During the pressure relief process, the shell component 5 can be quickly ruptured along the annular groove to quickly open the pressure relief area 56.
  • the area of the pressure relief zone 56 is D, which satisfies: 90 mm 2 ⁇ D ⁇ 1500 mm 2 .
  • the area of the shaded portion is the area of the pressure relief zone 56 .
  • the area of the pressure relief zone 56 is the area of the region defined by the deepest (innermost) level one notched groove 532 .
  • D can be 90mm2 , 95mm2 , 100mm2 , 150mm2, 200mm2 , 250mm2 , 300mm2 , 350mm2, 400mm2 , 450mm2 , 500mm2 , 550mm2 , 600mm2 , 650mm2 , 700mm2 , 750mm2 , 800mm2 , 900mm2 , 950mm2 , 1000mm2, 1050mm2, 1100mm2 , 1150mm2, 1200mm2 , 1250mm2 , 1300mm2 , 1350mm2 , 1400mm2 , 1450mm2 , 1500mm2 Any one of the two points or any range between them.
  • the housing component 5 has a first surface 54 and a second surface 55 that are oppositely disposed, the groove 53 is recessed from the first surface 54 toward the second surface 55, the groove 53 forms an outer edge 534 on the first surface 54, and the area of the housing component 5 outside the preset distance from the outer edge 534 is a non-weak area 51.
  • the preset distance is L.
  • L can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc.
  • the groove portion 53 includes only a primary notched groove 532, the notched groove 532 is disposed on the first surface 54, the groove side surface of the notched groove 532 intersects with the first surface 54 to form an outer edge 534, and the groove side surface of the notched groove 532 is disposed around the groove bottom surface of the notched groove 532.
  • the notched groove 532 is a groove extending along a closed trajectory, the groove side surface of the notched groove 532 intersects with the first surface 54 to form an inner ring line and an outer ring line located outside the inner ring line, and the outer ring line is the outer edge 534.
  • the groove portion 53 only includes the multi-stage notched groove 532, the outermost first-stage notched groove 532a is arranged on the first surface 54, and the groove side surface of the outermost first-stage notched groove 532a intersects with the first surface 54 to form an outer edge 534.
  • the notched groove 532 is a groove extending along a closed trajectory, the outermost first-stage notched groove 532a intersects with the first surface 54 to form an inner ring line and an outer ring line located outside the inner ring line, and the outer ring line is the outer edge 534.
  • the groove portion 53 further includes a primary groove 533, the groove 533 is disposed on the first surface 54, the groove side surface of the groove 533 intersects with the first surface 54 to form an outer edge 534, and the groove side surface of the groove 533 is arranged around the groove bottom surface of the groove 533.
  • the groove portion 53 further includes a multi-stage groove 533, the outermost primary groove 533a is disposed on the first surface 54, and the groove side surface of the outermost primary groove 533a intersects with the first surface 54 to form an outer edge 534.
  • the distance between the outer edge 534 and the inner edge 511 of the non-weak area 51 is a preset distance L
  • the shape of the inner edge 511 of the non-weak area 51 can be substantially the same as the shape of the outer edge 534.
  • the direction of the preset distance L can be perpendicular to the thickness direction of the non-weak area 51, that is, the preset distance L can be measured along the thickness direction perpendicular to the non-weak area 51.
  • the measurement can be performed in the area outside the outer edge 534.
  • the area of the shell component 5 beyond the preset distance from the outer edge 534 is the non-weak area 51.
  • the non-weak area 51 is a certain distance away from the groove portion 53.
  • the non-weak area 51 is not easily affected by the process of forming the groove portion 53, so that the grains of the non-weak area 51 are more uniform.
  • L 5 mm.
  • FIG. 9 and FIG15 in the embodiment where the first groove section 5321 and the third groove section 5323 of the notched groove 532 are arranged opposite to each other, taking the first groove section 5321 and the third groove section 5323 being parallel as an example, when the spacing between the first groove section 5321 and the third groove section 5323 is greater than 2*L, the inner edge 511 of the non-weak area 51 is partially located in the pressure relief area 56, so that the pressure relief area 56 is partially located in the non-weak area 51.
  • FIG35 is a schematic diagram of the structure of the housing component 5 provided in other embodiments of the present application.
  • the inner edge 511 of the non-weak area 51 is not located in the pressure relief area 56, and the inner edge 511 of the non-weak area 51 is roughly rectangular.
  • the distance between the first slot segment 5321 and the inner edge 511 of the non-weakened area 51 is L; along the length direction of the first slot segment 5321, the distance between the first slot segment 5321 and the inner edge 511 of the non-weakened area 51 is L; along the width direction of the third slot segment 5323, the distance between the third slot segment 5323 and the inner edge 511 of the non-weakened area 51 is L; along the length direction of the third slot segment 5323, the distance between the third slot segment 5323 and the inner edge 511 of the non-weakened area 51 is L.
  • FIG36 is a grain map (schematic diagram) of the shell component 5 provided in some other embodiments of the present application.
  • the shell component 5 also includes a transition zone 57, which connects the weak zone 52 and the non-weak zone 51.
  • the average grain size of the transition zone 57 is S3 , satisfying : S3 ⁇ S2 .
  • S 3 >S 1 .
  • the transition zone 57 is a portion of the shell component 5 connecting the weak zone 52 and the non-weak zone 51.
  • the transition zone 57 is arranged around the outside of the weak zone 52, and the non-weak zone 51 is surrounded by the outside of the transition zone 57.
  • the weak zone 52, the transition zone 57 and the non-weak zone 51 are integrally formed.
  • the average grain size of the transition zone 57 may gradually decrease from the non-weak zone 51 to the weak zone 52.
  • the average grain size of the transition zone 57 located outside the sink groove 533 may be greater than the average grain size of the transition zone 57 located at the bottom of the sink groove 533, the average grain size of the transition zone 57 located outside the sink groove 533 may be less than or equal to the average grain size S 2 of the non-weak zone 51, and the average grain size of the transition zone 57 located at the bottom of the sink groove 533 may be greater than the average grain size S 1 of the weak zone 52.
  • the transition area 57 serves to connect the weak area 52 and the non-weak area 51 , so that the weak area 52 and the non-weak area 51 are integrally formed.
  • FIG. 37 is a schematic diagram of the structure of the end cap 11 provided in some embodiments of the present application.
  • the housing component 5 is the end cap 11 , which is used to close the opening of the shell 12 , and the shell 12 is used to accommodate the electrode assembly 2 .
  • the end cap 11 is provided with a groove portion 53 to form a corresponding weak area 52 and a non-weak area 51.
  • the first surface 54 and the second surface 55 of the housing component 5 are two surfaces opposite to each other in the thickness direction of the end cap 11, that is, one of the first surface 54 and the second surface 55 is the inner surface of the end cap 11 in the thickness direction, and the other is the outer surface of the end cap 11 in the thickness direction.
  • the end cover 11 may be a circular or rectangular plate-shaped structure.
  • the end cover 11 is a rectangular plate-like structure.
  • the end cover 11 has a pressure relief function to ensure the safety of the battery cell 10 .
  • Figure 38 is a schematic diagram of the structure of the shell 12 provided in some embodiments of the present application
  • Figure 39 is a schematic diagram of the structure of the shell 12 provided in other embodiments of the present application.
  • the outer shell component 5 is the shell 12, and the shell 12 has an opening, and the shell 12 is used to accommodate the electrode assembly 2.
  • the shell 12 of the housing 1 is the housing component 5, and the end cover 11 of the housing 1 is used to close the opening of the shell 12.
  • the shell 12 can be a hollow structure with an opening formed at one end, or a hollow structure with openings formed at two opposite ends.
  • the shell 12 can be a cuboid, a cylinder, etc.
  • the outer shell component 5 is a shell 12 , so that the shell 12 has a pressure relief function to ensure the safety of the battery cell 10 .
  • the housing 12 includes a plurality of integrally formed wall portions 121 , the plurality of wall portions 121 together define an internal space of the housing 12 , and at least one of the wall portions 121 is provided with a groove portion 53 .
  • the groove 53 may be provided on one wall 121 to form an integrally formed weak area 52 and a non-weak area 51 on the wall 121; or the grooves 53 may be provided on a plurality of walls 121 to form an integrally formed weak area 52 and a non-weak area 51 on each wall 121 provided with the groove 53.
  • the first surface 54 and the second surface 55 of the housing component 5 are two surfaces opposite to each other in the thickness direction of the wall 121, that is, one of the first surface 54 and the second surface 55 is the inner surface of the wall 121 in the thickness direction, and the other is the outer surface of the wall 121 in the thickness direction.
  • the plurality of wall portions 121 are integrally formed, so that the wall portion 121 where the groove portion 53 is disposed has better reliability.
  • the multiple wall portions 121 include a bottom wall 121b and multiple side walls 121a surrounding the bottom wall 121b, and the housing 12 forms an opening at one end opposite to the bottom wall 121b.
  • the bottom wall 121b is provided with a groove portion 53; and/or at least one side wall 121a is provided with a groove portion 53.
  • the housing 12 is a hollow structure with an opening formed at one end.
  • the side walls 121a in the housing 12 may be three, four, five, six or more.
  • One, two, three, four, five, six or more side walls 121a may be provided with a groove 53.
  • the shell 12 is a rectangular parallelepiped.
  • the rectangular parallelepiped housing is suitable for square battery cells and can meet the large capacity requirements of the battery cells 10 .
  • the material of the housing component 5 includes aluminum alloy.
  • the housing component 5 made of aluminum alloy is light in weight, has good ductility, good plastic deformation capability, and is easy to form.
  • the aluminum alloy includes the following components by mass percentage: aluminum ⁇ 99.6%, copper ⁇ 0.05%, iron ⁇ 0.35%, magnesium ⁇ 0.03%, manganese ⁇ 0.03%, silicon ⁇ 0.25%, titanium ⁇ 0.03%, vanadium ⁇ 0.05%, zinc ⁇ 0.05%, and other single elements ⁇ 0.03%.
  • This aluminum alloy has lower hardness, better forming ability, reduces the forming difficulty of the groove 53, improves the forming accuracy of the groove 53, and improves the pressure relief consistency of the housing component 5.
  • 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 other elements total components ⁇ 0.15%.
  • the housing component 5 made of such an aluminum alloy has higher hardness, greater strength, and good anti-destruction ability.
  • An embodiment of the present application provides a battery cell 10, comprising a housing component 5 provided in any one of the above embodiments.
  • the battery cell 10 further includes a housing 12 having an opening, and the housing 12 is used to accommodate the electrode assembly 2.
  • the housing component 5 is an end cover 11, and the end cover 11 closes the opening.
  • the housing component 5 is a shell 12 having an opening, and the shell 12 is used to accommodate the electrode assembly 2.
  • the battery cell 10 further includes an end cover 11, which closes the opening.
  • An embodiment of the present application provides a battery 100, comprising a battery cell 10 provided in any one of the above embodiments.
  • FIG. 40 is a schematic diagram of the structure of a battery cell 10 provided in some embodiments of the present application, and the weak area 52 is located at the lower part of the battery cell 10 .
  • the portion of the battery cell 10 below the midplane Y of the shell 1 is the lower portion of the battery cell 10, wherein the midplane Y is perpendicular to the height direction of the shell 1, and the distances from the midplane Y to the two end surfaces of the shell 1 in the height direction are equal.
  • the shell 1 includes a shell 12 and an end cover 11, and the end cover 11 closes the opening of the shell 12.
  • the shell 12 and the end cover 11 are arranged along the height direction of the shell 1, and along the height direction of the shell 1, the midplane Y is located in the middle of the outer surface of the end cover 11 away from the shell 12 and the outer surface of the shell 12 away from the end cover 11.
  • the weak area 52 is located at the lower part of the battery cell 10, and the groove 53 is located at the lower part of the battery cell 10, and the weak area 52 and the groove 53 are both located below the midplane Y.
  • the weak area 52 can be located at the shell 12, and the weak area 52 can also be located at the end cover 11.
  • the weak area 52 can be located at the side wall 121a of the shell 12, and can also be located at the bottom wall 121b of the shell 12.
  • the bottom wall 121b of the shell 12 can be located below the end cover 11, and the weak area 52 is located below the midplane Y, so that the distance from the weak area 52 to the bottom wall 121b of the shell 12 is greater than the distance from the weak area 52 to the end cover 11.
  • the weak area 52 Since the weak area 52 is located at the lower part of the battery cell 10, during the use of the battery 100, the weak area 52 will be subjected to a large force under the gravity of the electrode assembly 2, electrolyte, etc. inside the battery cell 10. Since the weak area 52 and the non-weak area 51 are an integrally formed structure, they have good structural strength and better reliability, thereby increasing the service life of the battery cell 10.
  • the battery cell 10 includes a shell 12, which is used to accommodate the electrode assembly 2.
  • the shell 12 includes an integrally formed bottom wall 121b and multiple side walls 121a surrounding the bottom wall 121b.
  • the bottom wall 121b and the side walls 121a are integrally formed.
  • the shell 12 forms an opening at the end opposite to the bottom wall 121b, and the weak area 52 is located at the bottom wall 121b.
  • bottom wall 121b is located below the midplane Y.
  • the weak area 52 is located at the bottom wall 121b, so that the weak area 52 is set downward.
  • the battery 100 is generally installed below the passenger compartment, and the weak area 52 is set downward, so that the emissions discharged by the battery cell 10 in thermal runaway are ejected in the direction away from the passenger compartment, reducing the impact of the emissions on the passenger compartment and reducing the risk of safety accidents.
  • the battery cell 10 includes an end cover 11 , which is used to close an opening of a shell 12 , and the shell 12 is used to accommodate the electrode assembly 2 .
  • the weak area 52 is located at the end cover 11 .
  • end cover 11 is located below the midplane Y.
  • the weak area 52 is located at the end cover 11, so that the weak area 52 is set downward.
  • the emissions in the battery cell 10 will spray downward, reducing the risk of safety accidents.
  • An embodiment of the present application provides an electrical device, comprising the battery 100 provided in any one of the above embodiments.
  • the embodiments of the present application provide an end cap 11 for a battery cell 10, and the end cap 11 includes an integrally formed non-weak area 51 and a weak area 52.
  • the end cap 11 is provided with a groove 53, the non-weak area 51 is formed around the groove 53, and the weak area 52 is formed at the bottom of the groove 53, and the weak area 52 is configured to be destroyed when the battery cell 10 releases internal pressure.
  • the end cap 11 has a first surface 54 facing away from the interior of the battery cell 10, and the groove 53 forms an outer edge 534 on the first surface 54.
  • the average grain size of the weak area 52 is S 1
  • the average grain size of the non-weak area 51 is S 2
  • the minimum thickness of the weak area 52 is A
  • the minimum thickness of the non-weak area 51 is B
  • the hardness of the weak area 52 is H 1
  • the hardness of the non-weak area 51 is H 2
  • the following conditions are satisfied: 0.1 ⁇ S 1 /S 2 ⁇ 0.5, 5 ⁇ A/S 1 ⁇ 20, 190HBW/mm ⁇ H 1 /A ⁇ 4000HBW/mm, 1 ⁇ H 1 /H 2 ⁇ 2.5, 0.2 ⁇ A/B ⁇ 0.5.
  • the present application provides a shell 12 for a battery cell 10, and the shell 12 includes a non-weak area 51 and a weak area 52 formed in one piece.
  • the shell 12 is provided with a groove 53, the non-weak area 51 is formed around the groove 53, and the weak area 52 is formed at the bottom of the groove 53, and the weak area 52 is configured to be destroyed when the battery cell 10 releases internal pressure.
  • the shell 12 has a first surface 54 facing away from the interior of the battery cell 10, and the groove 53 forms an outer edge 534 on the first surface 54.
  • the average grain size of the weak area 52 is S 1
  • the average grain size of the non-weak area 51 is S 2
  • the minimum thickness of the weak area 52 is A
  • the minimum thickness of the non-weak area 51 is B
  • the hardness of the weak area 52 is H 1
  • the hardness of the non-weak area 51 is H 2
  • the following conditions are satisfied: 0.1 ⁇ S 1 /S 2 ⁇ 0.5, 5 ⁇ A/S 1 ⁇ 20, 190HBW/mm ⁇ H 1 /A ⁇ 4000HBW/mm, 1 ⁇ H 1 /H 2 ⁇ 2.5, 0.2 ⁇ A/B ⁇ 0.5.
  • the battery cell 10 is a square battery cell
  • the end cover 11 in the battery cell 10 serves as the outer shell component 5
  • the capacity of the battery cell 10 is 150 Ah
  • the chemical system is NCM.
  • the average grain size test of the weak area 52 and the non-weak area 51 adopts the electron backscatter diffraction (EBSD) method.
  • the shell component 5 is cut into 3 sections, and the cross sections at both ends of the middle section have weak areas 52 and non-weak areas 51.
  • the cutting direction is perpendicular to the length direction of the weak area 52, and the cutting equipment does not change the grain structure.
  • the middle section is selected for sampling, and then the sample is electrolytically polished, and the sample is fixed on a sample table inclined at 70°.
  • the appropriate magnification is selected, and an EBSD scan is performed using a scanning electron microscope (SEM) equipped with an electron backscatter diffraction (EBSD) accessory. According to the scanning results, the average grain size (i.e., the equal area circle diameter of the complete grains in the inspection surface) is finally calculated.
  • SEM scanning electron microscope
  • EBSD electron backscatter diffraction
  • the housing component 5 is cut into three sections, and the middle section is taken as a sample.
  • the sections at both ends of the sample have weak areas 52 and non-weak areas 51.
  • the cutting direction is perpendicular to the length direction of the weak area 52.
  • the middle section is polished to fully remove burrs, the sample is placed on a three-dimensional coordinate measuring instrument to measure the thickness of the weak area 52 and non-weak area 51 on the section.
  • the housing component 5 takes the middle section as the sample, and the sections at both ends of the sample have weak areas 52 and non-weak areas 51.
  • the cutting direction is perpendicular to the length direction of the weak area 52.
  • the sample is placed horizontally (the direction of the sample section is parallel to the extrusion direction of the hardness tester) on the Brinell hardness tester for hardness measurement. If the width of the weak area 52 is less than 1mm or the size of the indenter of the Brinell hardness tester is much larger than the width of the weak area 52, a non-standard indenter should be processed for hardness measurement according to the Brinell hardness measurement and conversion principle.
  • the battery cell 10 is placed at 25 ⁇ 2°C and cycled with 5%-97% SOC.
  • the gas pressure inside the battery cell 10 is monitored and 500 groups of tests are performed at the same time.
  • the test cutoff condition is: the battery cell 10 life drops to 80% SOH or any group of battery cells 10 cracks in the weak area 52 during the cycle.
  • the judgment condition for the cracking of the weak area 52 is: the internal gas pressure value of the battery cell 10 drops, and its drop value is > 10% of the maximum gas pressure.
  • a small heating film is built into the battery cell 10.
  • the heating film is energized to heat the battery cell 10 until the battery cell 10 experiences thermal runaway, and then observe whether the battery cell 10 explodes. Repeat 500 sets of tests, and calculate the explosion rate of the battery cell 10.
  • the explosion rate the number of explosions/the total number*100%.
  • the test results of the average grain size S 1 of the weak area 52, the average grain size S 2 of the non-weak area 51, the minimum thickness A of the weak area 52, the minimum thickness B of the non-weak area 51, the hardness H 1 of the weak area 52, and the hardness H 2 of the non-weak area 51 are shown in Table 1.
  • the units of S 1 and S 2 are mm, the units of A and B are mm, and the units of H 1 and H 2 are HBW;
  • the cracking rate Q 1 of the weak area 52 under normal use conditions of the battery cell 10 and the explosion rate Q 2 of the battery cell 10 during thermal runaway are shown in Table 2.
  • Embodiment 27 3% 3.6% Embodiment 28 3.6% 1.6% Embodiment 29 5% 1% Embodiment 30 7.4% 0.4% Embodiment 31 10.4% 0.4% Comparative Example 1 20.2% 0.6% Comparative Example 2 22.4% 0.4% Comparative Example 3 26.4% 0.4%
  • Example 7 when S 1 /S 2 ⁇ 0.05, it is more difficult for the weak area 52 to be destroyed when the battery cell 10 is in thermal runaway, and the risk of explosion of the battery cell 10 is significantly increased if the pressure relief is not timely. It can be seen from Examples 3 to 5 that when 0.1 ⁇ S 1 /S 2 ⁇ 0.5, the cracking rate of the weak area 52 under normal use conditions of the battery cell 10 and the explosion rate of the battery cell 10 in thermal runaway are both low, ensuring that the weak area 52 can be destroyed in time when the battery cell 10 is in thermal runaway, and ensuring that the weak area 52 has sufficient strength under normal use conditions of the battery cell 10.

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Abstract

本申请实施例提供了一种外壳部件、电池单体、电池及用电设备。其中，外壳部件包括一体成型的非薄弱区和薄弱区，外壳部件设置有槽部，非薄弱区形成于槽部的周围，薄弱区形成于槽部的底部，薄弱区被配置为在电池单体泄放内部压力时被破坏。其中，薄弱区的平均晶粒尺寸为S1，非薄弱区的平均晶粒尺寸为S2，S1/S2≤0.9。减小薄弱区的平均晶粒尺寸，提高薄弱区材料力学性能，提高了薄弱区的韧性和抗疲劳强度，降低薄弱区在电池单体正常使用条件下被破坏的风险，提高了电池单体的使用寿命。

Description

外壳部件、电池单体、电池及用电设备 技术领域
本申请涉及电池技术领域，具体而言，涉及一种外壳部件、电池单体、电池及用电设备。
背景技术
随着新能源技术的发展，电池的应用越来越广泛，例如应用于手机、笔记本电脑、电瓶车、电动汽车、电动飞机、电动轮船、电动玩具汽车、电动玩具轮船、电动玩具飞机和电动工具等上。
在电池技术的发展中，除了提高电池单体的安全性外，电池单体的使用寿命也是一个需要考虑的问题。因此，如何提高电池单体的使用寿命，是电池技术中一个亟待解决的问题。
发明内容
本申请实施例提供一种外壳部件、电池单体、电池及用电设备，能够有效提高电池的使用寿命。
第一方面，本申请实施例提供一种外壳部件，用于电池单体，包括一体成型的非薄弱区和薄弱区，外壳部件设置有槽部，非薄弱区形成于槽部的周围，薄弱区形成于槽部的底部，薄弱区被配置为在电池单体泄放内部压力时被破坏；其中，薄弱区的平均晶粒尺寸为S 1，非薄弱区的平均晶粒尺寸为S 2，满足：S 1/S 2≤0.9。
上述技术方案中，S 1/S 2≤0.9，薄弱区的平均晶粒尺寸与非薄弱区的平均晶粒尺寸相差较大，减小薄弱区的平均晶粒尺寸，提高薄弱区材料力学性能，提高了薄弱区的韧性和抗疲劳强度，降低薄弱区在电池单体正常使用条件下被破坏的风险，提高了电池单体的使用寿命。
在一些实施例中，S 1/S 2≥0.05。S 1/S 2过小，薄弱区的成型难度增大，且薄弱区的强度过大，薄弱区在电池单体热失控时被破坏的难度加大，容易出现泄压不及时的情况。因此，S 1/S 2≥0.05，降低成型薄弱区的成型难度，提高电池单体在热失控时的泄压及时性。
在一些实施例中，0.1≤S 1/S 2≤0.5。使得外壳部件的综合性能更优，保证薄弱区在电池单体热失控时能够及时被破坏的情况下，保证薄弱区在电池单体正常使用条件下具有足够的强度。
在一些实施例中，0.4μm≤S 1≤75μm。S 1过大，薄弱区的韧性和抗疲劳强度较差；S 1过小，薄弱区的成型难度较大，且薄弱区的强度过大，薄弱区在电池单体热失控时被破坏的难度加大，容易出现泄压不及时的情况。因此，0.4μm≤S 1≤75μm，一方面，降低薄弱区的成型难度，提高电池单体在热失控时的泄压及时性；另一方面，提高了薄弱区的韧性和抗疲劳强度，降低薄弱区在电池单体正常使用条件下被破坏的风险。
在一些实施例中，1μm≤S 1≤10μm。使得外壳部件的综合性能更优，保证薄弱区在电池单体热失控时能够及时被破坏的情况下，保证薄弱区在电池单体正常使用条件下具有足够的强度。
在一些实施例中，10μm≤S 2≤150μm。
在一些实施例中，30μm≤S 2≤100μm。
在一些实施例中，薄弱区的最小厚度为A，满足：1≤A/S 1≤100。A/S 1过小，在薄弱区的厚度方向，薄弱区的晶粒层数越少，薄弱区的抗疲劳强度过小；A/S 1过大，在薄弱区的厚度方向，薄弱区的晶粒层数过多，薄弱区的强度过大，容易出现薄弱区在电池单体热失控时不能及时被破坏的风险。因此，1≤A/S 1≤100，一方面，使得薄弱区在厚度方向的晶粒层数较多，提高薄弱区的抗疲劳强度，降低薄弱区在电池单体正常使用条件下被破坏的风险；另一方面，使得薄弱区能够在电池单体热失控时能够更为及时的被破坏，以达到及时泄压的目的。
在一些实施例中，5≤A/S 1≤20。使得外壳部件的综合性能更优，保证薄弱区在电池单体热失控时能够及时被破坏的情况下，保证了薄弱区在电池单体正常使用条件下具有足够的抗疲劳强度，提高电池单体的使用寿命。
在一些实施例中，薄弱区的最小厚度为A，薄弱区的硬度为H 1，满足：5HBW/mm≤H 1/A≤10000HBW/mm。不仅考虑到薄弱区的厚度对外壳部件的性能的影响，还考虑到薄弱区的硬度对外壳部件的性能的影响，5HBW/mm≤H 1/A≤10000HBW/mm，既能够使得薄弱区在电池单体正常使用条件下具有足够的强度，薄弱区不易因疲劳而破坏，提高电池单体的使用寿命；又能够使得外壳部件在电池单体热失控时通过薄弱区及时泄压，降低电池单体发生爆炸的风险，提高电池单体的安全性。
在一些实施例中，190HBW/mm≤H 1/A≤4000HBW/mm。使得外壳部件综合性能更优，保证薄弱区在电池单体热失控时能够及时被破坏的情况下，保证薄弱区在电池单体正常使用条件下具有足够的强度。在保证电池单体的安全性的前提下，提高了电池单体的使用寿命。
在一些实施例中，0.02mm≤A≤1.6mm。A过小，薄弱区的成型难度困难，且在成型过程中，容易造成薄弱区损伤；A过大，薄弱区在电池单体热失控时被破坏的难度加大，容易出现泄压不及时的情况。因此，0.02mm ≤A≤1.6mm，在降低泄压区的成型难度的情况下，提高了电池单体在热失控时的泄压及时性。
在一些实施例中，0.06mm≤A≤0.4mm。进一步降低泄压区的成型难度，并提高电池单体在热失控时的泄压及时性。
在一些实施例中，薄弱区的硬度为H 1，非薄弱区的硬度为H 2，满足：H 1＞H 2。这样，相当于提高了薄弱区的硬度，从而提高了薄弱区的强度，降低薄弱区在电池单体正常使用条件下被破坏的风险。
在一些实施例中，H 1/H 2≤5。H 1/H 2过大，可能会出现薄弱区在电池单体热失控时很难被破坏的情况。因此，H 1/H 2≤5，降低薄弱区在电池单体热失控时无法及时被破坏的风险，提高电池单体的安全性。
在一些实施例中，H 1/H 2≤2.5。
在一些实施例中，5HBW≤H 2≤150HBW。
在一些实施例中，5HBW≤H 1≤200HBW。
在一些实施例中，薄弱区的最小厚度为A，非薄弱区的最小厚度为B，满足：0.05≤A/B≤0.95。A/B过小，可能会出现薄弱区的强度不足的情况。A/B过大，可能会出现薄弱区在电池单体热失控时不容易被破坏的情况，泄压不及时，导致电池单体爆炸的概率增大。因此，0.05≤A/B≤0.95，既能够降低薄弱区在电池单体正常使用条件下破裂的概率，又能够降低电池单体热失控时发生爆炸的概率。
在一些实施例中，0.12≤A/B≤0.8。这样，使得外部部件综合性能更优，在保证薄弱区在电池单体热失控时能够及时被破坏的情况下，保证薄弱区在电池单体正常使用条件下具有足够的强度。
在一些实施例中，0.2≤A/B≤0.5。
在一些实施例中，0.02mm≤A≤1.6mm。
在一些实施例中，0.06mm≤A≤0.4mm。
在一些实施例中，1mm≤B≤5mm。B过大，非薄弱区的厚度较大，外壳部件的用料更多，外壳部件的重量大，经济性差。B过小，非薄弱区的厚度较小，外壳部件的抗变形能力较差。因此，1mm≤B≤5mm，使得外壳部件具有较好的经济性，且具有较好的抗变形能力。
在一些实施例中，1.2mm≤B≤3.5mm。使得外壳部件具有更好的经济性和抗变形能力。
在一些实施例中，2mm≤B≤3mm。
在一些实施例中，外壳部件具有泄压区，槽部包括一级刻痕槽，刻痕槽沿着泄压区的边缘设置，泄压区被配置为能够以刻痕槽为边界打开，薄弱区形成刻痕槽的底部。在薄弱区被破坏时，泄压区能够以薄弱区为边界打开，以实现泄压，增大了外壳部件的泄压面积。
在一些实施例中，外壳部件具有相对设置的第一表面和第二表面，刻痕槽从第一表面向靠近第二表面的方向凹陷。刻痕槽即为槽部，结构简单。在成型时，可以在第一表面成型刻痕槽，成型简单，提高生产效率，降低生产成本。
在一些实施例中，外壳部件包括相对设置的第一表面和第二表面，槽部包括多级刻痕槽，多级刻痕槽沿第一表面到第二表面的方向依次设置于外壳部件，薄弱区形成于最远离第一表面的一级刻痕槽的底部；其中，外壳部件具有泄压区，每级刻痕槽沿着泄压区的边缘设置，泄压区被配置为能够以最远离第一表面的一级刻痕槽为边界打开。在成型时，可以在外壳部件上逐级成型多级刻痕槽，可以降低每级刻痕槽的成型深度，从而降低外壳部件在成型每级刻痕槽时所受到的成型力，降低外壳部件产生裂纹的风险，外壳部件不易因在设置刻痕槽的位置产生裂纹而失效，提高了外壳部件的使用寿命。
在一些实施例中，最远离第二表面的一级刻痕槽从第一表面向靠近第二表面的方向凹陷。槽部由多级刻痕槽构成，在成型时，可以从第一表面到第二表面的方向逐渐加工出多级刻痕槽。
在一些实施例中，外壳部件包括相对设置的第一表面和第二表面，槽部还包括一级沉槽，沉槽从第一表面向靠近第二表面的方向凹陷，泄压区形成于沉槽的槽底壁。沉槽的设置，在保证最终的薄弱区的厚度一定的情况下，可以降低刻痕槽的深度，从而降低外壳部件在成型刻痕槽时所受到的成型力，降低外壳部件产生裂纹的风险。此外，沉槽能够为泄压区在打开过程中提供避让空间，即使第一表面被障碍物遮挡，泄压区仍然能够打开泄压。
在一些实施例中，外壳部件包括相对设置的第一表面和第二表面，槽部还包括多级沉槽，多级沉槽沿第一表面到第二表面的方向依次设置于外壳部件，最远离第二表面的一级沉槽从第一表面向靠近第二表面凹陷，泄压区形成于最远离第一表面的一级沉槽的槽底壁。在成型多级沉槽时，能够减小每级沉槽的成型深度，能够降低成型每级沉槽时外壳部件受到的成型力，降低外壳部件产生裂纹的风险。此外，多级沉槽能够为泄压区在打开过程中提供避让空间，即使第一表面被障碍物遮挡，泄压区仍然能够打开泄压。
在一些实施例中，沉槽的内部空间为圆柱体、棱柱体、圆台体或棱台体。这种结构的沉槽结构简单，易 于成型，能够为泄压区在打开过程中提供更多地避让空间。
在一些实施例中，刻痕槽包括第一槽段和第二槽段，第一槽段与第二槽段相交，第一槽段和第二槽段沿着泄压区的边缘设置。第一槽段和第二槽段相交位置应力更为集中，使得薄弱区能够在第一槽段与第二槽段相交的位置最先被破坏。在电池单体的起爆压力一定的情况下，薄弱区可以做得更厚，减小刻痕槽的成型深度。
在一些实施例中，刻痕槽还包括第三槽段，第一槽段和第三槽段相对设置，第二槽段与第三槽段相交，第一槽段、第二槽段和第三槽段沿着泄压区的边缘设置。这样，泄压区能够以第一槽段、第二槽段和第三槽段为边界打开，在电池单体泄压时，泄压区打开更加容易，实现外壳部件的大面积泄压。
在一些实施例中，第一槽段、第二槽段和第三槽段依次连接，第一槽段、第二槽段和第三槽段限定出一个泄压区。
在一些实施例中，第一槽段、第二槽段和第三槽段限定出两个泄压区，两个泄压区分别位于第二槽段的两侧。两个泄压区能够以对开的形式打开泄压，可有效提高外壳部件的泄压效率。
在一些实施例中，刻痕槽为沿非封闭轨迹延伸的槽。泄压区可以以翻转的方式打开，泄压区打开后最终与外壳部件的其他区域相连，降低泄压区打开后发生飞溅的风险。
在一些实施例中，刻痕槽为圆弧形槽。圆弧形槽结构简单，易于成型。在泄压过程中，泄压区能够沿着圆弧形槽快速破裂，以使泄压区快速打开。
在一些实施例中，刻痕槽为沿封闭轨迹延伸的槽。在泄压过程中，外壳部件能够沿刻痕槽破裂，使得泄压区可以以脱离的方式打开，增大了外壳部件的泄压面积，提高外壳部件的泄压速率。
在一些实施例中，刻痕槽为环形槽。环形槽结构简单，易于成型，在泄压过程中，外壳部件可以沿着环形槽快速破裂，以使泄压区快速打开。
在一些实施例中，泄压区的面积为D，满足：90mm 2≤D≤1500mm 2。D过小，外壳部件的泄压面积较小，电池单体热失控时的泄压及时性较差；D过大，泄压区的抗冲击能力较差，泄压区受力后的变形增大，薄弱区在电池单体正常使用条件下容易被破坏，影响电池单体的使用寿命。因此，90mm 2≤D≤1500mm 2，既能够提高电池单体的使用寿命，又能够提高电池单体的安全性。
在一些实施例中，150mm 2≤D≤1200mm 2。
在一些实施例中，200mm 2≤D≤1000mm 2。
在一些实施例中，250mm 2≤D≤800mm 2。
在一些实施例中，外壳部件具有相对设置的第一表面和第二表面，槽部从第一表面向靠近第二表面的方向凹陷，槽部在第一表面形成外边缘，外壳部件距离外边缘预设距离以外的区域为非薄弱区。这样，非薄弱区不易受到在成型槽部的过程中的影响，使得非薄弱区的晶粒更加均匀。
在一些实施例中，预设距离为L，满足：L＝5mm。
在一些实施例中，外壳部件还包括过渡区，过渡区连接薄弱区和非薄弱区，过渡区的平均晶粒尺寸为S 3，满足：S 3≤S 2。过渡区起到连接薄弱区和非薄弱区的作用，实现薄弱区和非薄弱区一体成型。
在一些实施例中，外壳部件为端盖，端盖用于封闭壳体的开口，壳体用于容纳电极组件。使得端盖具有泄压功能，保证电池单体的安全性。
在一些实施例中，外壳部件为壳体，壳体具有开口，壳体用于容纳电极组件。使得壳体具有泄压功能，保证电池单体的安全性。
在一些实施例中，壳体包括一体成型的多个壁部，多个壁部共同限定出壳体的内部空间，至少一个壁部设置有槽部。多个壁部一体成型，使得设置槽部的壁部具有更好的可靠性。
在一些实施例中，多个壁部包括底壁和围设于底壁的周围的多个侧壁，壳体在与底壁相对的一端形成开口；底壁设置有槽部；和/或，至少一个侧壁设置有槽部。
在一些实施例中，壳体为长方体。适用于方形电池单体，能够满足电池单体的大容量要求。
在一些实施例中，外壳部件的材质包括铝合金。铝合金的外壳部件重量轻，具有很好的延展性，易于成型。
在一些实施例中，铝合金包括以下质量百分含量的成分：铝≥99.6％，铜≤0.05％，铁≤0.35％，镁≤0.03％，锰≤0.03％，硅≤0.25％，钛≤0.03％，钒≤0.05％，锌≤0.05％，其他单个元素≤0.03％。这种铝合金硬度更低，具有更好的成型能力，降低槽部的成型难度，提高了槽部的成型精度，提高了外壳部件的泄压一致性。
在一些实施例中，铝合金包括以下质量百分含量的成分：铝≥96.7％，0.05％≤铜≤0.2％，铁≤0.7％，锰 ≤1.5％，硅≤0.6％，锌≤0.1％，其他单个元素成分≤0.05％，其他元素总成分≤0.15％。由这种铝合金制成的外壳部件硬度更高，强度大，具有良好的抗破坏能力。
第二方面，本申请实施例提供一种电池单体，包括上述第一方面任意一个实施例提供的外壳部件。
在一些实施例中，电池单体还包括壳体，壳体具有开口，壳体用于容纳电极组件；外壳部件为端盖，端盖封闭开口。
在一些实施例中，外壳部件为壳体，壳体具有开口，壳体用于容纳电极组件；电池单体还包括端盖，端盖封闭开口。
第三方面，本申请实施例提供一种电池，包括上述第二方面任意一个实施例提供的电池单体。
在一些实施例中，薄弱区位于电池单体的下部。在电池使用过程中，在电池单体内部的电极组件、电解液等的重力作用下，薄弱区会受到较大的作用力，由于薄弱区与非薄弱区为一体成型结构，具有很好的结构强度，具有更好的可靠性，提高电池单体的使用寿命。
在一些实施例中，电池单体包括壳体，壳体用于容纳电极组件，壳体包括底壁和围设于底壁的周围的多个侧壁，底壁与侧壁一体成型，壳体在与底壁相对的一端形成开口，薄弱区位于底壁。
在一些实施例中，电池单体包括端盖，端盖用于封闭壳体的开口，壳体用于容纳电极组件，薄弱区位于端盖。
第四方面，本申请实施例提供一种用电设备，包括上述第三方面任意一个实施例提供的电池。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，应当理解，以下附图仅示出了本申请的某些实施例，因此不应被看作是对范围的限定，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他相关的附图。
图1为本申请一些实施例提供的车辆的结构示意图；
图2为本申请一些实施例提供的电池的爆炸图；
图3为本申请一些实施例提供的电池单体的爆炸图；
图4为本申请一些实施例提供的外壳部件的结构示意图；
图5为图4所示的外壳部件的C-C剖视图；
图6为图5所示的外壳部件的晶粒图(示意图)；
图7为图5所示的外壳部件的E处的局部放大图；
图8为本申请另一些实施提供的外壳部件的局部放大图；
图9为本申请又一些实施例提供的外壳部件的结构示意图(示出一级刻痕槽)；
图10为图9所示的外壳部件的E-E剖视图；
图11为本申请再一些实施例提供的外壳部件的结构示意图(示出一级刻痕槽)；
图12为图11所示的外壳部件的F-F剖视图；
图13为本申请另一些实施例提供的外壳部件的结构示意图(示出一级刻痕槽)；
图14为图13所示的外壳部件的G-G剖视图；
图15为本申请又一些实施例提供的外壳部件的结构示意图(示出两级刻痕槽)；
图16为图15所示的外壳部件的K-K剖视图；
图17为本申请再一些实施例提供的外壳部件的结构示意图(示出两级刻痕槽)；
图18为图17所示的外壳部件的M-M剖视图；
图19为本申请另一些实施例提供的外壳部件的结构示意图(示出两级刻痕槽)；
图20为图19所示的外壳部件的N-N剖视图；
图21为本申请一些实施例提供的外壳部件的轴测图；
图22为图21所示的外壳部件的结构示意图(示出一级刻痕槽和一级沉槽)；
图23为图22所示的外壳部件的O-O剖视图；
图24为本申请再一些实施例提供的外壳部件的结构示意图(示出一级刻痕槽和一级沉槽)；
图25为图24所示的外壳部件的P-P剖视图；
图26为本申请另一些实施例提供的外壳部件的结构示意图(示出一级刻痕槽和一级沉槽)；
图27为图26所示的外壳部件的Q-Q剖视图；
图28为本申请一些实施例提供的外壳部件的结构示意图(示出一级刻痕槽和两级沉槽)；
图29为图28所示的外壳部件的R-R剖视图；
图30为本申请再一些实施例提供的外壳部件的结构示意图(示出一级刻痕槽和两级沉槽)；
图31为图30所示的外壳部件的S-S剖视图；
图32为本申请另一些实施例提供的外壳部件的结构示意图(示出一级刻痕槽和两级沉槽)；
图33为图32所示的外壳部件的T-T剖视图；
图34为本申请一些实施例提供的外壳部件的结构示意图(示出一级刻痕槽，刻痕槽为V形)；
图35为本申请其他实施例提供的外壳部件的结构示意图；
图36为本申请另一些实施例提供的外壳部件的晶粒图(示意图)；
图37为本申请一些实施例提供的端盖的结构示意图；
图38为本申请一些实施例提供的壳体的结构示意图；
图39为本申请另一些实施例提供的壳体的结构示意图；
图40为本申请一些实施例提供的电池单体的结构示意图。
图标：1-外壳；11-端盖；12-壳体；121-壁部；121a-侧壁；121b-底壁；2-电极组件；21-正极耳；22-负极耳；3-正电极端子；4-负电极端子；5-外壳部件；51-非薄弱区；511-内边缘；52-薄弱区；53-槽部；531-槽部的槽底面；532-刻痕槽；532a-最外侧的一级刻痕槽；532b-最内侧的一级刻痕槽；5321-第一槽段；5322-第二槽段；5323-第三槽段；533-沉槽；533a-最外侧的一级沉槽；533b-最内侧的一级沉槽；5331-沉槽的槽底壁；534-外边缘；54-第一表面；55-第二表面；56-泄压区；57-过渡区；10-电池单体；20-箱体；201-第一部分；202-第二部分；100-电池；200-控制器；300-马达；1000-车辆；Y-中平面。
具体实施方式
为使本申请实施例的目的、技术方案和优点更加清楚，下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
除非另有定义，本申请所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同；本申请中在申请的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请；本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形，意图在于覆盖不排他的包含。本申请的说明书和权利要求书或上述附图中的术语“第一”、“第二”等是用于区别不同对象，而不是用于描述特定顺序或主次关系。
在本申请中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。
本申请中术语“和/或”，仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，本申请中字符“/”，一般表示前后关联对象是一种“或”的关系。
在本申请的实施例中，相同的附图标记表示相同的部件，并且为了简洁，在不同实施例中，省略对相同部件的详细说明。应理解，附图示出的本申请实施例中的各种部件的厚度、长宽等尺寸，以及集成装置的整体厚度、长宽等尺寸仅为示例性说明，而不应对本申请构成任何限定。
本申请中出现的“多个”指的是两个以上(包括两个)。
本申请实施例中，电池单体可以为二次电池，二次电池是指在电池单体放电后可通过充电的方式使活性材料激活而继续使用的电池单体。
电池单体可以为锂离子电池、钠离子电池、钠锂离子电池、锂金属电池、钠金属电池、锂硫电池、镁离子电池、镍氢电池、镍镉电池、铅蓄电池等，本申请实施例对此并不限定。
本申请的实施例所提到的电池可以包括一个或多个电池单体以提供更高的电压和容量的单一的物理模块。电池单体有多个时，多个电池单体通过汇流部件串联、并联或混联。
在一些实施例中，电池可以为电池模块，电池单体有多个时，多个电池单体排列并固定形成一个电池模块。
在一些实施例中，电池可以为电池包，电池包包括箱体和电池单体，电池单体或电池模块容纳于箱体中。
在一些实施例中，箱体可以作为车辆的底盘结构的一部分。例如，箱体的部分可以成为车辆的地板的至少一部分，或者，箱体的部分可以成为车辆的横梁和纵梁的至少一部分。
在一些实施例中，电池可以为储能装置。储能装置包括储能集装箱、储能电柜等。
电池技术的发展要同时考虑多方面的设计因素，例如，能量密度、循环寿命、放电容量、充放电倍率等性能参数，另外，还需要考虑电池的安全性。
在电池单体中，为保证电池单体的安全性，可以在电池单体的外壳上设置泄压机构，在电池单体热失控时，通过泄压机构泄放电池单体内部的压力，以提高电池单体的安全性。
对于一般的电池单体而言，泄压机构焊接于外壳，以将泄压机构固定于外壳。以泄压机构为设置于外壳的端盖上的防爆片为例，在电池单体热失控时，防爆片被破坏，以将电池单体内部的排放物排出，以达到泄放电池单体内部的压力的目的。由于泄压机构与外壳焊接连接，在电池单体长期使用过程中焊接位置可能会出现裂纹，导致焊接位置的强度降低，容易出现焊接位置在电池单体内部的压力未达到泄压机构的起爆压力时被破坏的情况，导致泄压机构失效，泄压机构的可靠性较低。
为提高泄压机构的可靠性，发明人研究发现，可以将泄压机构与外壳设置成一体成型结构，即将外壳的一部分作为泄压机构。比如，将端盖的局部进行弱化处理，使得端盖的局部的强度降低，形成薄弱区，从而形成一体式泄压机构，这样，可以有效提高泄压机构的可靠性。
发明人注意到，在外壳上形成一体式泄压机构后，外壳的薄弱区的力学性能较差，在电池单体正常使用条件下，容易出现薄弱区因电池单体内部压力长期变化而疲劳破坏，影响电池单体的使用寿命。
鉴于此，本申请实施例提供一种外壳部件，通过在外壳部件上设置槽部，形成一体成型的非薄弱区和薄弱区，非薄弱区形成于槽部的周围，薄弱区形成于槽部的底部，薄弱区的平均晶粒尺寸为S 1，非薄弱区的平均晶粒尺寸为S 2，S 1/S 2≤0.9。
在这样的外壳部件中，S 1/S 2≤0.9，减小薄弱区的平均晶粒尺寸，提高薄弱区材料力学性能，提高了薄弱区的韧性和抗疲劳强度，降低薄弱区在电池单体正常使用条件下被破坏的风险，提高了电池单体的使用寿命。
本申请实施例描述的技术方案适用于电池以及使用电池的用电设备。
用电设备可以是车辆、手机、便携式设备、笔记本电脑、轮船、航天器、电动玩具和电动工具等等。车辆可以是燃油汽车、燃气汽车或新能源汽车，新能源汽车可以是纯电动汽车、混合动力汽车或增程式汽车等；航天器包括飞机、火箭、航天飞机和宇宙飞船等等；电动玩具包括固定式或移动式的电动玩具，例如，游戏机、电动汽车玩具、电动轮船玩具和电动飞机玩具等等；电动工具包括金属切削电动工具、研磨电动工具、装配电动工具和铁道用电动工具，例如，电钻、电动砂轮机、电动扳手、电动螺丝刀、电锤、冲击电钻、混凝土振动器和电刨等等。本申请实施例对上述用电设备不做特殊限制。
以下实施例为了方便说明，以用电设备为车辆为例进行说明。
请参照图1，图1为本申请一些实施例提供的车辆1000的结构示意图。车辆1000的内部设置有电池100，电池100可以设置在车辆1000的底部或头部或尾部。电池100可以用于车辆1000的供电，例如，电池100可以作为车辆1000的操作电源。
车辆1000还可以包括控制器200和马达300，控制器200用来控制电池100为马达300供电，例如，用于车辆1000的启动、导航和行驶时的工作用电需求。
在本申请一些实施例中，电池100不仅仅可以作为车辆1000的操作电源，还可以作为车辆1000的驱动电源，代替或部分地代替燃油或天然气为车辆1000提供驱动动力。
请参照图2，图2为本申请一些实施例提供的电池100的爆炸图。电池100包括电池单体10和箱体20，箱体20用于容纳电池单体10。
其中，箱体20是容纳电池单体10的部件，箱体20为电池单体10提供放置空间，箱体20可以采用多种结构。在一些实施例中，箱体20可以包括第一部分201和第二部分202，第一部分201与第二部分202相互盖合，以限定出用于容纳电池单体10的放置空间。第一部分201和第二部分202可以是多种形状，比如，长方体、圆柱体等。第一部分201可以是一侧开放的空心结构，第二部分202也可以是一侧开放的空心结构，第二部分202的开放侧盖合于第一部分201的开放侧，则形成具有放置空间的箱体20。也可以是第一部分201为一侧开放的空心结构，第二部分202为板状结构，第二部分202盖合于第一部分201的开放侧，则形成具有放置空间的箱体20。作为示例，电池单体10可以为圆柱形电池单体、棱柱电池单体、软包电池单体或其它形状的电池单体10，棱柱电池单体包括方壳电池单体、刀片形电池单体、多棱柱电池，多棱柱电池例如为六棱柱电池等，本申请没有特别的限制。
在电池100中，电池单体10可以是一个、也可以是多个。若电池单体10为多个，多个电池单体10之间可串联或并联或混联，混联是指多个电池单体10中既有串联又有并联。可以是多个电池单体10先串联或并联或混联组成电池模块，多个电池模块再串联或并联或混联形成一个整体，并容纳于箱体20内。也可以是所有电池单体10之间直接串联或并联或混联在一起，再将所有电池单体10构成的整体容纳于箱体20内。
请参照图3，图3为本申请一些实施例提供的电池单体10的爆炸图。电池单体10可以包括外壳1和电极组件2。
外壳1用于容纳电极组件2及电解质等部件。外壳1可以为钢壳、铝壳、塑料壳(如聚丙烯)、复合金属壳(如铜铝复合外壳)或铝塑膜等。作为示例，外壳1可以包括壳体12和端盖11。
壳体12可以是一端形成开口的空心结构，壳体12也可以是相对的两端形成开口的空心结构。壳体12的材质可以是多种，比如，铜、铁、铝、钢、铝合金等。
端盖11是封闭壳体12的开口以将电池单体10的内部环境与外部环境隔绝的部件。端盖11与壳体12共同限定出用于容纳电极组件2、电解液以及其他部件的容纳空间。端盖11可以通过焊接或卷封的方式连接于壳体12，以封闭壳体12的开口。端盖11的形状可以与外壳1的形状相适配，比如，壳体12为长方体结构，端盖11为与外壳1相适配的矩形板状结构，再如，壳体12为圆柱体，端盖11为与壳体12相适配的圆形板状结构。端盖11的材质也可以是多种，比如，铜、铁、铝、钢、铝合金等。
在电池单体10中，端盖11可以是一个，也可以是两个。在壳体12为两端形成开口的空心结构的实施例中，端盖11可以对应设置两个，两个端盖11分别封闭壳体12的两个开口，两个端盖11与壳体12共同限定出容纳空间。在壳体12为一端形成开口的空心结构的实施例中，端盖11可以对应设置一个，端盖11封闭壳体12一端的开口，一个端盖11与壳体12共同限定出容纳空间。
电极组件2包括正极、负极以及隔离件。在电池单体10充放电过程中，活性离子(例如锂离子)在正极和负极之间往返嵌入和脱出。隔离件设置在正极和负极之间，可以起到防止正负极短路的作用，同时可以使活性离子通过。
在一些实施例中，正极可以为正极片，正极片可以包括正极集流体以及设置在正极集流体至少一个表面的正极活性材料。
作为示例，正极集流体具有在其自身厚度方向相对的两个表面，正极活性材料设置在正极集流体相对的两个表面的任意一者或两者上。
作为示例，正极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可采用银表面处理的铝或不锈钢、不锈钢、铜、铝、镍、炭精电极、碳、镍或钛等。复合集流体可包括高分子材料基层和金属层。复合集流体可通过将金属材料(铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯、聚对苯二甲酸乙二醇酯、聚对苯二甲酸丁二醇酯、聚苯乙烯、聚乙烯等的基材)上而形成。
作为示例，正极活性材料可包括以下材料中的至少一种：含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料，还可以使用其他可被用作电池正极活性材料的传统材料。这些正极活性材料可以仅单独使用一种，也可以将两种以上组合使用。其中，含锂磷酸盐的示例可包括但不限于磷酸铁锂(如LiFePO 4(也可以简称为LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO 4)、磷酸锰锂与碳的复合材料、磷酸锰铁锂、磷酸锰铁锂与碳的复合材料中的至少一种。锂过渡金属氧化物的示例可包括但不限于锂钴氧化物(如LiCoO 2)、锂镍氧化物(如LiNiO 2)、锂锰氧化物(如LiMnO 2、LiMn2O 4)、锂镍钴氧化物、锂锰钴氧化物、锂镍锰氧化物、锂镍钴锰氧化物(如LiNi 1/3Co 1/3Mn 1/3O 2(也可以简称为NCM 333)、LiNi 0.5Co 0.2Mn 0.3O 2(也可以简称为NCM 523)、LiNi 0.5Co 0.25Mn 0.25O 2(也可以简称为NCM 211)、LiNi 0.6Co 0.2Mn 0.2O 2(也可以简称为NCM 622)、LiNi 0.8Co 0.1Mn 0.1O 2(也可以简称为NCM 811)、锂镍钴铝氧化物(如LiNi 0.85Co 0.15Al 0.05O 2)及其改性化合物等中的至少一种。
在一些实施例中，正极可以采用泡沫金属。泡沫金属可以为泡沫镍、泡沫铜、泡沫铝、泡沫合金、或泡沫碳等。泡沫金属作为正极时，泡沫金属表面可以不设置正极活性材料，当然也可以设置正极活性材料。作为示例，在泡沫金属内还可以填充或/和沉积有锂源材料、钾金属或钠金属，锂源材料为锂金属和/或富锂材料。
在一些实施例中，负极可以为负极片，负极片可以包括负极集流体以及设置在负极集流体至少一个表面上的负极活性材料。
作为示例，负极集流体具有在其自身厚度方向相对的两个表面，负极活性材料设置在负极集流体相对的两个表面中的任意一者或两者上。
作为示例，负极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可以采用银表面处理的铝或不锈钢、不锈钢、铜、铝、镍、炭精电极、用碳、镍或钛等。复合集流体可包括高分子材料基层和金属层。复合集流体可通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯、聚对苯二甲酸乙二醇酯、聚对苯二甲酸丁二醇酯、聚苯乙烯、聚乙烯等的基材)上而形成。
作为示例，负极活性材料可采用本领域公知的用于电池的负极活性材料。作为示例，负极活性材料可包括以下材料中的至少一种：人造石墨、天然石墨、软炭、硬炭、硅基材料、锡基材料和钛酸锂等。硅基材料可选自单质硅、硅氧化合物、硅碳复合物、硅氮复合物以及硅合金中的至少一种。锡基材料可选自单质锡、锡氧化合物以及锡合金中的至少一种。但本申请并不限定于这些材料，还可以使用其他可被用作电池负极活性材料的传统材料。这些负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。
在一些实施例中，负极可以采用泡沫金属。泡沫金属可以为泡沫镍、泡沫铜、泡沫铝、泡沫合金、或泡沫碳等。泡沫金属作为负极片时，泡沫金属表面可以不设置负极活性材料，当然也可以设置负极活性材料。
作为示例，在负极集流体内还可以填充或/和沉积有锂源材料、钾金属或钠金属，锂源材料为锂金属和/或富锂材料。
在一些实施例中，正极集流体的材料可以为铝，负极集流体的材料可以为铜。
在一些实施方式中，电极组件2还包括隔离件，隔离件设置在正极和负极之间。
在一些实施方式中，隔离件为隔离膜。本申请对隔离膜的种类没有特别的限制，可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。
作为示例，隔离膜的主要材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯，陶瓷中的至少一种。隔离膜可以是单层薄膜，也可以是多层复合薄膜，没有特别限制。在隔离膜为多层复合薄膜时，各层的材料可以相同或不同，没有特别限制。隔离件可以是单独的一个部件位于正负极之间，也可以附着在正负极的表面。
在一些实施方式中，隔离件为固态电解质。固态电解质设于正极和负极之间，同时起到传输离子和隔离正负极的作用。
在一些实施方式中，电池单体10还包括电解质，电解质在正、负极之间起到传导离子的作用。本申请对电解质的种类没有具体的限制，可根据需求进行选择。电解质可以是液态的、凝胶态的或固态的。
其中，液态电解质包括电解质盐和溶剂。
在一些实施方式中，电解质盐可选自六氟磷酸锂、四氟硼酸锂、高氯酸锂、六氟砷酸锂、双氟磺酰亚胺锂、双三氟甲磺酰亚胺锂、三氟甲磺酸锂、二氟磷酸锂、二氟草酸硼酸锂、二草酸硼酸锂、二氟二草酸磷酸锂及四氟草酸磷酸锂中的至少一种。
在一些实施方式中，溶剂可选自碳酸亚乙酯、碳酸亚丙酯、碳酸甲乙酯、碳酸二乙酯、碳酸二甲酯、碳酸二丙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸亚丁酯、氟代碳酸亚乙酯、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丁酸甲酯、丁酸乙酯、1,4-丁内酯、环丁砜、二甲砜、甲乙砜及二乙砜中的至少一种。溶剂也可选醚类溶剂。醚类溶剂可以包括乙二醇二甲醚、乙二醇二乙醚、二乙二醇二甲醚、三乙二醇二甲醚、四乙二醇二甲醚、1,3-二氧戊环、四氢呋喃、甲基四氢呋喃、二苯醚及冠醚中的一种或多种。
其中，凝胶态电解质包括以聚合物作为电解质的骨架网络，搭配离子液体-锂盐。
其中，固态电解质包括聚合物固态电解质、无机固态电解质、复合固态电解质。
作为示例，聚合物固态电解质可以为聚醚(聚氧化乙烯)、聚硅氧烷、聚碳酸酯、聚丙烯腈、聚偏氟乙烯、聚甲基丙烯酸甲酯、单离子聚合物、聚离子液体-锂盐、纤维素等。
作为示例，无机固态电解质可以为氧化物固体电解质(晶态的钙钛矿、钠超导离子导体、石榴石、非晶态的LiPON薄膜)、硫化物固体电解质(晶态的锂超离子导体(锂鍺磷硫、硫银鍺矿)、非晶体硫化物)以及卤化物固体电解质、氮化物固体电解质及氢化物固体电解质中的一种或多种。
作为示例，复合固态电解质通过在聚合物固体电解质中增加无机固态电解质填料形成。
在一些实施方式中，电极组件2为卷绕结构。正极片、负极片卷绕成卷绕结构。
在一些实施方式中，电极组件2为叠片结构。
作为示例，正极片、负极片可分别设置多个，多个正极片和多个负极片交替层叠设置。
作为示例，正极片可设置多个，负极片折叠形成多个层叠设置的折叠段，相邻的折叠段之间夹持一个正极片。
作为示例，正极片和负极片均折叠形成多个层叠设置的折叠段。
作为示例，隔离件可设置多个，分别设置在任意相邻的正极片或负极片之间。
作为示例，隔离件可连续地设置，通过折叠或者卷绕方式设置在任意相邻的正极片或负极片之间。
在一些实施方式中，电极组件2的形状可以为圆柱状，扁平状或多棱柱状等。
在一些实施方式中，电极组件2设有极耳，极耳可以将电流从电极组件2导出。极耳包括正极耳21和负极耳22。
电池单体10还可以包括电极端子，电极端子可以设置于外壳1上，电极端子用于与电极组件2的极耳电连接，以输出电池单体10的电能。电极端子与极耳可以直接连接，比如，电极端子与极耳直接焊接。电极端子与极耳也可以间接连接，比如，电极端子与极耳通过集流构件间接连接。集流构件可以是金属导体，比如，铜、铁、铝、钢、铝合金等。
如图3所示，以壳体12为一端形成开口的空心结构为例，端盖11上可以设置两个电极端子，两个电极端子分别为正电极端子3和负电极端子4，正电极端子3与正极耳21电连接，负电极端子4与负极耳22电连接。
请参照图4-图7，图4为本申请一些实施例提供的外壳部件5的结构示意图；图5为图4所示的外壳部件5的C-C剖视图；图6为图5所示的外壳部件5的晶粒图(示意图)；图7为图5所示的外壳部件5的E处的局部放大图。本申请实施例提供一种外壳部件5，用于电池单体10，包括一体成型的非薄弱区51和薄弱区52，外壳部件5设置有槽部53，非薄弱区51形成于槽部53的周围，薄弱区52形成于槽部53的底部，薄弱区52被配置为在电池单体10泄放内部压力时被破坏。其中，薄弱区52的平均晶粒尺寸为S 1，非薄弱区51的平均晶粒尺寸为S 2，满足：S 1/S 2≤0.9。
外壳部件5为能够与其他部件共同容纳电极组件2的部件，外壳部件5为外壳1的一部分，可以是外壳1的端盖11为外壳部件5，也可以是外壳1的壳体12为外壳部件5。外壳部件5可以是金属材质，比如，铜、铁、铝、钢、铝合金等，外壳部件5可以是铝塑膜。
薄弱区52为外壳部件5较其他区域更为薄弱的部分，在电池单体10内部压力达到阈值时，外壳部件5的薄弱区52能够被破坏，以泄放电池单体10内部的压力。薄弱区52可以破裂、脱离等方式被破坏。比如，在电池单体10内部压力达到阈值时，薄弱区52在电池单体10内部的排放物(气体、电解液等)的作用下破裂，使得电池单体10内部的排放物能够顺利排出。薄弱区52可以是多种形状，比如，矩形、圆形、椭圆形、环形、圆弧形、U形、H形等。薄弱区52的厚度可以是均匀的，也可以是不均匀的。
薄弱区52形成于槽部53的底部，槽部53可以通过多种方式成型，比如，槽部53可以通过冲压、铣削加工、激光刻蚀等成型方式成型，以实现薄弱区52与非薄弱区51一体成型。在外壳部件5上冲压成型槽部53后，外壳部件5在设置槽部53的区域减薄，对应形成薄弱区52。槽部53可以是一级槽，沿槽部53的深度方向，槽部53的槽侧面是连续的，比如，槽部53为内部空间呈长方体、柱型体等的槽。槽部53也可以是多级槽，多级槽沿槽部53的深度方向排布，在相邻的两级槽中，内侧(更深位置)的一级槽设置于外侧(更浅位置)的一级槽的槽底面，比如，槽部53为阶梯槽。在成型时，可以沿槽部53的深度方向逐级冲压成型多级槽，薄弱区52形成于多级槽中位于最深位置(最内侧)的一级槽的底部。
非薄弱区51形成于槽部53的周围，非薄弱区51的强度大于薄弱区52的强度，薄弱区52相较于非薄弱区51更容易被破坏。通过冲压的方式在外壳部件5上形成槽部53时，非薄弱区51可以是外壳部件5未被冲压的部分。非薄弱区51的厚度可以是均匀的，也可以是不均匀的。
平均晶粒尺寸的测量方法可以参见GB 6394-2017中的截点法，在此不在赘述。在测量薄弱区52的平均晶粒尺寸时，可以沿薄弱区52的厚度方向进行测量；在测量非薄弱区51的平均晶粒尺寸时，可以沿非薄弱区51的厚度方向进行测量。
在图5中，薄弱区52的厚度方向与非薄弱区51的厚度方向一致，均为Z向。
S 1/S 2可以是0.01、0.03、0.04、0.05、0.1、0.15、0.2、0.25、0.3、0.35、0.4、0.45、0.5、0.55、0.6、0.65、0.7、0.75、0.8、0.85、0.9中任意一者点值或者任意两者之间的范围值。
在本申请实施例中，薄弱区52和非薄弱区51一体成型，外壳部件5的可靠性更高。由于S 1/S 2≤0.9，薄弱区52的平均晶粒尺寸与非薄弱区51的平均晶粒尺寸相差较大，减小薄弱区52的平均晶粒尺寸，达到细化薄弱区52晶粒的目的，提高了薄弱区52材料力学性能，提高了薄弱区52的韧性和抗疲劳强度，降低薄弱区52在电池单体10正常使用条件下被破坏的风险，提高了电池单体10的使用寿命。
在一些实施例中，S 1/S 2≥0.05。
发明人注意到，当S 1/S 2＜0.05时，薄弱区52的成型难度增大，且薄弱区52的强度过大，薄弱区52在电池单体10热失控时被破坏的难度加大，容易出现泄压不及时的情况。
因此，S 1/S 2≥0.05，降低成型薄弱区52的成型难度，提高电池单体10在热失控时的泄压及时性。
在一些实施例中，0.1≤S 1/S 2≤0.5。
S 1/S 2可以是0.1、0.12、0.15、0.17、0.2、0.22、0.25、0.27、0.3、0.32、0.35、0.37、0.4、0.42、0.45、0.47、0.5中任意一者点值或者任意两者之间的范围值。
在本实施例中，0.1≤S 1/S 2≤0.5，使得外壳部件5的综合性能更优，保证薄弱区52在电池单体10热失控时能够及时被破坏的情况下，保证薄弱区52在电池单体10正常使用条件下具有足够的强度。
在一些实施例中，0.4μm≤S 1≤75μm。
S 1可以是0.4μm、0.5μm、1μm、2μm、3μm、4μm、5μm、10μm、15μm、20μm、25μm、28μm、30μm、35μm、36μm、40μm、45μm、49μm、50μm、55μm、60μm、65μm、70μm、72μm、75μm中任意一者点值或者任意两者之间的范围值。
发明人注意到，S 1＞75μm，薄弱区52的韧性和抗疲劳强度较差；S 1＜0.4mm，薄弱区52的成型难度较大，且薄弱区52的强度过大，薄弱区52在电池单体10热失控时被破坏的难度加大，容易出现泄压不及时的情况。
因此，0.1μm≤S 1≤75μm，一方面，降低薄弱区52的成型难度，提高电池单体10在热失控时的泄压及时性；另一方面，提高了薄弱区52的韧性和抗疲劳强度，降低薄弱区52在电池单体10正常使用条件下被破坏的风险。
在一些实施例中，1μm≤S 1≤10μm。
S 1可以是1μm、1.5μm、1.6μm、2μm、2.5μm、2.6μm、3μm、3.5μm、3.6μm、4μm、4.5μm、4.6μm、5μm、5.5μm、5.6μm、6μm、6.5μm、6.6μm、7μm、7.5μm、7.6μm、8μm、8.5μm、8.6μm、9μm、9.5μm、9.6μm、10μm中任意一者点值或者任意两者之间的范围值。
在本实施例中，1μm≤S 1≤10μm，使得外壳部件5的综合性能更优，保证薄弱区52在电池单体10热失控时能够及时被破坏的情况下，保证薄弱区52在电池单体10正常使用条件下具有足够的强度。
在一些实施例中，10μm≤S 2≤150μm。
S 2可以是10μm、15μm、20μm、25μm、30μm、35μm、40μm、45μm、50μm、55μm、60μm、65μm、70μm、75μm、80μm、85μm、90μm、95μm、100μm、105μm、110μm、115μm、120μm、125μm、130μm、135μm、140μm、145μm、150μm中任意一者点值或者任意两者之间的范围值。
在一些实施例中，30μm≤S 2≤100μm。
S 2可以是30μm、32μm、35μm、37μm、40μm、42μm、45μm、47μm、50μm、52μm、55μm、57μm、60μm、62μm、65μm、67μm、70μm、72μm、75μm、77μm、80μm、82μm、85μm、87μm、90μm、92μm、95μm、97μm、100μm中任意一者点值或者任意两者之间的范围值。
在一些实施例中，薄弱区52的最小厚度为A，满足：1≤A/S 1≤100。
A/S 1可以是1、2、4、5、10、15、20、21、22、23、25、30、33、34、35、37、38、40、45、50、55、60、65、70、75、80、85、90、93、94、95、100中任意一者点值或者任意两者之间的范围值。
当A/S 1＜1时，在薄弱区52的厚度方向，薄弱区52的晶粒层数越少，薄弱区52的抗疲劳强度过小；当A/S 1＞100时，在薄弱区52的厚度方向，薄弱区52的晶粒层数过多，薄弱区52的强度过大，容易出现薄弱区52在电池单体10热失控时不能及时被破坏的风险。
因此，1≤A/S 1≤100，一方面，使得薄弱区52在厚度方向的晶粒层数较多，提高薄弱区52的抗疲劳强度，降低薄弱区52在电池单体10正常使用条件下被破坏的风险；另一方面，使得薄弱区52能够在电池单体10热失控时能够更为及时的被破坏，以达到及时泄压的目的。
在一些实施例中，5≤A/S 1≤20。
A/S 1可以是5、5.5、6、6.5、7、7.5、8、8.5、9、9.5、10、10.5、11、11.5、12、12.5、13、13.5、14、14.5、15、15.5、16、16.5、17、17.5、18、18.5、19、19.5、20中任意一者点值或者任意两者之间的范围值。
在本实施例中，5≤A/S 1≤20，使得外壳部件5的综合性能更优，保证薄弱区52在电池单体10热失控 时能够及时被破坏的情况下，保证了薄弱区52在电池单体10正常使用条件下具有足够的抗疲劳强度，提高电池单体10的使用寿命。
在一些实施例中，薄弱区52的最小厚度为A，薄弱区52的硬度为H 1，满足：5HBW/mm≤H 1/A≤10000HBW/mm。
H 1/A可以是5HBW/mm、6HBW/mm、7HBW/mm、20HBW/mm、50HBW/mm、61HBW/mm、62HBW/mm、63HBW/mm、64HBW/mm、75HBW/mm、90HBW/mm、100HBW/mm、120HBW/mm、150HBW/mm、190HBW/mm、500HBW/mm、1000HBW/mm、1200HBW/mm、1750HBW/mm、1800HBW/mm、2100HBW/mm、4000HBW/mm、5000HBW/mm、8000HBW/mm、9000HBW/mm、10000HBW/mm中任意一者点值或者任意两者之间的范围值。
薄弱区52的硬度为布氏硬度，单位为HBW。布氏硬度的测量方法可参见GB/T 23.1-2018中的测量原理进行实施。在实际测量过程中，薄弱区52的硬度可以在薄弱区52厚度方向上的内表面或外表面进行测量获得。以外壳部件5为电池单体10的端盖11为例，可以在薄弱区52背离电池单体10内部的外表面上测量薄弱区52的硬度，也可以在薄弱区52面向电池单体10内部的内表面上测量薄弱区52的硬度。
当H 1/A＞10000HBW/mm时，薄弱区52较薄且硬度较大，这样会导致薄弱区52非常薄脆，薄弱区52在电池单体10的正常使用条件下容易被破坏，电池单体10的使用寿命较短。当H 1/A＜5HBW/mm时，薄弱区52较厚且硬度较小，在电池单体10热失控时，薄弱区52会被拉伸延展，泄压及时性较差。
在本实施例中，不仅考虑到薄弱区52的厚度对外壳部件5的性能的影响，还考虑到薄弱区52的硬度对外壳部件5的性能的影响，5HBW/mm≤H 1/A≤10000HBW/mm，既能够使得薄弱区52在电池单体10正常使用条件下具有足够的强度，薄弱区52不易因疲劳而破坏，提高电池单体10的使用寿命；又能够使得外壳部件5在电池单体10热失控时通过薄弱区52及时泄压，降低电池单体10发生爆炸的风险，提高电池单体10的安全性。
在一些实施例中，190HBW/mm≤H 1/A≤4000HBW/mm。
H 1/A可以是190HBW/mm、250HBW/mm、280HBW/mm、300HBW/mm、350HBW/mm、400HBW/mm、450HBW/mm、500HBW/mm、600HBW/mm、700HBW/mm、875HBW/mm、1000HBW/mm、1200HBW/mm、1500HBW/mm、1750HBW/mm、1800HBW/mm、2000HBW/mm、2100HBW/mm、2500HBW/mm、3000HBW/mm、3500HBW/mm、4000HBW/mm中任意一者点值或者任意两者之间的范围值。
在本实施例中，190HBW/mm≤H 1/A≤4000HBW/mm，使得外壳部件5综合性能更优，保证薄弱区52在电池单体10热失控时能够及时被破坏的情况下，保证薄弱区52在电池单体10正常使用条件下具有足够的强度。在保证电池单体10的安全性的前提下，提高了电池单体10的使用寿命。
在一些实施例中，0.02mm≤A≤1.6mm。
A可以是0.02mm、0.04mm、0.05mm、0.06mm、0.1mm、0.15mm、0.2mm、0.25mm、0.3mm、0.35mm、0.4mm、0.45mm、0.5mm、0.55mm、0.6mm、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、1.42mm、1.43mm、1.45mm、1.47mm、1.5mm、1.55mm、1.6mm中任意一者点值或者任意两者之间的范围值。
当A＜0.02mm时，薄弱区52的成型难度困难，且在成型过程中，容易造成薄弱区52损伤；当A＞1.6mm，薄弱区52在电池单体10热失控时被破坏的难度加大，容易出现泄压不及时的情况。
因此，0.02mm≤A≤1.6mm，在降低泄压区56的成型难度的情况下，提高了电池单体10在热失控时的泄压及时性。
在一些实施例中，0.06mm≤A≤0.4mm。
A可以是0.06mm、0.07mm、0.08mm、0.1mm、0.15mm、0.18mm、0.2mm、0.25mm、0.3mm、0.35mm、0.4mm中任意一者点值或者任意两者之间的范围值。
在本实施例中，0.06mm≤A≤0.4mm，进一步降低薄弱区52的成型难度，并提高电池单体10在热失控时的泄压及时性。
在一些实施例中，薄弱区52的硬度为H 1，非薄弱区51的硬度为H 2，满足：H 1＞H 2。
非薄弱区51的硬度为布氏硬度，单位为HBW。在实际测量过程中，非薄弱区51的硬度可以在非薄弱区51厚度方向上的内表面或外表面进行测量获得。以外壳部件5为电池单体10的端盖11为例，可以在非薄弱区51背离电池单体10内部的外表面上测量非薄弱区51的硬度，也可以在非薄弱区51面向电池单体10内部的内表面上测量非薄弱区51的硬度。
在本实施例中，H 1＞H 2，相当于提高了薄弱区52的硬度，从而提高了薄弱区52的强度，降低薄弱区52在电池单体10正常使用条件下被破坏的风险。
在一些实施例中，H 1/H 2≤5。
H 1/H 2可以是1.1、1.5、2、2.5、3、3.5、3.6、4、4.5、5中任意一者点值或者任意两者之间的范围值。
当H 1/H 2＞5时，可能会导致薄弱区52的硬度过大，可能会出现薄弱区52在电池单体10热失控时很难被破坏的情况。
因此，H 1/H 2≤5，降低薄弱区52在电池单体10热失控时无法及时被破坏的风险，提高电池单体10的安全性。
在一些实施例中，H 1/H 2≤2.5。
H 1/H 2可以是1.1、1.11、1.12、1.2、1.25、1.3、1.4、1.5、1.6、1.7、1.71、1.72、1.8、1.9、2、2.1、2.2、2.3、2.4、2.5中任意一者点值或者任意两者之间的范围值。
在本实施例中，H 1/H 2≤2.5，能够进一步降低薄弱区52在电池单体10热失控时无法及时被破坏的风险。
在一些实施例中，5HBW≤H 2≤150HBW。
H 2可以是5HBW、8HBW、9HBW、9.5HBW、10HBW、15HBW、16HBW、19HBW、20HBW、30HBW、40HBW、50HBW、52HBW、52.5HBW、53HBW、60HBW、70HBW、80HBW、90HBW、100HBW、110HBW、120HBW、130HBW、140HBW、150HBW中任意一者点值或者任意两者之间的范围值。
在一些实施例中，5HBW≤H 1≤200HBW。
H 1可以是5HBW、6HBW、8HBW、10HBW、15HBW、19HBW、20HBW、30HBW、50HBW、60HBW、70HBW、80HBW、90HBW、100HBW、110HBW、120HBW、130HBW、140HBW、150HBW、160HBW、170HBW、180HBW、190HBW、200HBW中任意一者点值或者任意两者之间的范围值。
在一些实施例中，请参照图7和图8，图8为本申请另一些实施提供的外壳部件5的局部放大图。薄弱区52的最小厚度为A，非薄弱区51的最小厚度为B，满足：0.05≤A/B≤0.95。
薄弱区52的最小厚度为薄弱区52最薄位置的厚度。非薄弱区51的最小厚度为非薄弱区51最薄位置的厚度。
如图7和图8所示，外壳部件5具有相对设置的第一表面54和第二表面55，槽部53从第一表面54向靠近第二表面55的方向凹陷，外壳部件5位于槽部的槽底面531与第二表面55之间的部分为薄弱区52。
第一表面54与第二表面55可以平行设置，也可以呈小角度设置，若第一表面54与第二表面55呈小角度设置，比如，两者所呈角度在10度以内，第一表面54与第二表面55之间的最小距离即为非薄弱区51的最小厚度；如图7和图8所示，若第一表面54与第二表面55平行，第一表面54与第二表面55之间的距离即为非薄弱区51的最小厚度。
槽部的槽底面531可以是平面，也可以是曲面。若槽部的槽底面531为平面，槽部的槽底面531与第二表面55可以平行，也可以呈小角度设置。若槽部的槽底面531与第二表面55呈小角度设置，比如，两者所呈角度在10度以内，槽部的槽底面531与第二表面55之间的最小距离即为薄弱区52的最小厚度；如图7所示，若槽部的槽底面531与第二表面55平行，槽部的槽底面531与第二表面55之间的距离即为薄弱区52的最小厚度。如图8所示，若槽部的槽底面531为曲面，比如，槽部的槽底面531为圆弧面，槽部的槽底面531与第二表面55之间的最小距离即为薄弱区52的最小厚度。
A/B可以是0.05、0.06、0.07、0.08、0.1、0.15、0.2、0.25、0.3、0.35、0.4、0.45、0.5、0.55、0.6、0.65、0.7、0.8、0.85、0.9、0.95中任意一者点值或者任意两者之间的范围值。
当A/B＜0.05时，可能会出现薄弱区52的强度不足的情况，薄弱区52在电池单体10正常使用条件下破裂的概率增大。当A/B＞0.95时，可能会出现薄弱区52在电池单体10热失控时不容易被破坏的情况，泄压不及时，导致电池单体10爆炸的概率增大。因此，0.05≤A/B≤0.95，既能够降低薄弱区52在电池单体10正常使用条件下破裂的概率，又能够降低电池单体10热失控时发生爆炸的概率。
在一些实施例中，0.12≤A/B≤0.8。
A/B可以是0.12、0.13、0.14、0.15、0.17、0.2、0.22、0.25、0.27、0.3、0.32、0.35、0.37、0.4、0.42、0.45、0.47、0.5、0.52、0.55、0.57、0.6、0.62、0.65、0.66、0.67、0.7、0.72、0.75、0.77、0.8中任意一者点值或者任意两者之间的范围值。
在本实施例中，0.12≤A/B≤0.8，使得外部部件综合性能更优，在保证薄弱区52在电池单体10热失控时能够及时被破坏的情况下，保证薄弱区52在电池单体10正常使用条件下具有足够的强度。在通过冲压的方式成型槽部53时，将A/B控制在0.12～0.8之间，能够更容易使得S 1/S 2≤0.5，以达到细化薄弱区52晶粒的目的。
在一些实施例中，0.2≤A/B≤0.5。
A/B可以是0.2、0.21、0.22、0.23、0.24、0.25、0.26、0.27、0.28、0.29、0.3、0.31、0.32、 0.33、0.34、0.35、0.36、0.37、0.38、0.39、0.4、0.41、0.42、0.43、0.44、0.45、0.46、0.47、0.48、0.49、0.5中任意一者点值或者任意两者之间的范围值。
在本实施例中，将A/B控制在0.2～0.5之间，进一步降低薄弱区52在电池单体10正常使用条件下被破坏的风险，并保证薄弱区52在电池单体10热失控时及时被破坏，提高泄压及时性。
在一些实施例中，0.02mm≤A≤1.6mm。
进一步地，0.06mm≤A≤0.4mm。
在一些实施例中，1mm≤B≤5mm。
B可以是1mm、2mm、3mm、4mm、5mm中任意一者点值或者任意两者之间的范围值。
当B＞5mm时，非薄弱区51的厚度较大，外壳部件5的用料更多，外壳部件5的重量大，经济性差。当B＜1mm时，非薄弱区51的厚度较小，外壳部件5的抗变形能力较差。
因此，1mm≤B≤5mm，使得外壳部件5具有较好的经济性，且具有较好的抗变形能力。
进一步地，1.2mm≤B≤3.5mm。
B可以是1.2mm、1.25mm、1.3mm、1.4mm、1.5mm、1.6mm、1.7mm、1.8mm、1.9mm、2mm、2.1mm、2.2mm、2.3mm、2.4mm、2.5mm、2.6mm、2.7mm、2.8mm、2.9mm、3mm、3.1mm、3.2mm、3.3mm、3.4mm、3.5mm中任意一者点值或者任意两者之间的范围值。
在本实施例中，1.2mm≤B≤3.5mm，使得外壳部件5具有更好的经济性和抗变形能力。
进一步地，2mm≤B≤3mm。
在一些实施例中，请参照图9-图14，图9为本申请又一些实施例提供的外壳部件5的结构示意图(示出一级刻痕槽532)；图10为图9所示的外壳部件5的E-E剖视图；图11为本申请再一些实施例提供的外壳部件5的结构示意图(示出一级刻痕槽532)；图12为图11所示的外壳部件5的F-F剖视图；图13为本申请另一些实施例提供的外壳部件5的结构示意图(示出一级刻痕槽532)；图14为图13所示的外壳部件5的G-G剖视图。外壳部件5具有泄压区56，槽部53包括一级刻痕槽532，刻痕槽532沿着泄压区56的边缘设置，泄压区56被配置为能够以刻痕槽532为边界打开，薄弱区52形成刻痕槽532的底部。
泄压区56为外壳部件5在薄弱区52被破坏后能够打开的区域。比如，在电池单体10内部压力达到阈值时，薄弱区52裂开，泄压区56在电池单体10内部的排放物的作用下向外打开。在此过程中，薄弱区52沿着刻痕槽532裂开，泄压区56打开，从而实现泄压区56以刻痕槽532为边界打开。泄压区56打开后，外壳部件5在与泄压区56相对应的位置可以形成排放口，电池单体10内部的排放物可以通过排放口排出，以泄放电池单体10内部的压力。
刻痕槽532可以通过多种方式成型于外壳部件5，比如，冲压成型、铣削加工成型、激光刻蚀成型等。槽部53中的刻痕槽532仅为一级，通过一次冲压则可成型该一级刻痕槽532。刻痕槽532可以是多种形状的槽，比如，环形槽、弧形槽、U形槽、H形槽等。薄弱区52形成于刻痕槽532的底部，薄弱区52的形状与刻痕槽532的形状相同，比如，薄弱区52为U形槽，薄弱区52则沿U形轨迹延伸。
作为示例，刻痕槽532的最大宽度为X，X≤10mm。刻痕槽532的最宽位置的宽度即为刻痕槽532的最大宽度。
在本实施例中，薄弱区52形成刻痕槽532的底部，在薄弱区52被破坏时，泄压区56能够以薄弱区52为边界打开，以实现泄压，增大了外壳部件5的泄压面积。
在一些实施例中，请继续参照图10、图12和图14所示，外壳部件5具有相对设置的第一表面54和第二表面55，刻痕槽532从第一表面54向靠近第二表面55的方向凹陷。
可以是第一表面54为外壳部件5面向电池单体10内部的内表面，第二表面55为外壳部件5背离电池单体10内部的外表面；也可以是第一表面54为外壳部件5背离电池单体10内部的外表面，第二表面55为外壳部件5面向电池单体10内部的内表面。作为示例，第一表面54平行于第二表面55，非薄弱区51的最小厚度即为第一表面54与第二表面55之间的距离。
刻痕槽532的槽底面即为槽部的槽底面531。外壳部件5在刻痕槽532的槽底面与第二表面55之间的部分为刻痕槽532的槽底壁，刻痕槽532的槽底壁即为薄弱区52。
在本实施例中，槽部53中仅包括一级刻痕槽532，刻痕槽532即为槽部53，槽部53为一级槽，结构简单。在成型时，可以在第一表面54成型刻痕槽532，成型简单，提高生产效率，降低生产成本。
在一些实施例中，请参照图15-图20，图15为本申请又一些实施例提供的外壳部件5的结构示意图(示出两级刻痕槽532)；图16为图15所示的外壳部件5的K-K剖视图；图17为本申请再一些实施例提供的外壳部件 5的结构示意图(示出两级刻痕槽532)；图18为图17所示的外壳部件5的M-M剖视图；图19为本申请另一些实施例提供的外壳部件5的结构示意图(示出两级刻痕槽532)；图20为图19所示的外壳部件5的N-N剖视图。外壳部件5包括相对设置的第一表面54和第二表面55，槽部53包括多级刻痕槽532，多级刻痕槽532沿第一表面54到第二表面55的方向依次设置于外壳部件5，薄弱区52形成于最远离第一表面54的一级刻痕槽532的底部。其中，外壳部件5具有泄压区56，每级刻痕槽532沿着泄压区56的边缘设置，泄压区56被配置为能够以最远离第一表面54的一级刻痕槽532为边界打开。
槽部53包括多级刻痕槽532，可理解的，槽部53为多级槽。每级刻痕槽532沿着泄压区56的边缘设置，可理解的，多级刻痕槽532均围绕泄压区56设置，使得多级刻痕槽532的延伸方向基本相同，使得多级刻痕槽532的形状基本相同。槽部53中的刻痕槽532可以是两级、三级、四级或者更多。各级刻痕槽532可以通过冲压成型的方式成型于外壳部件5。在成型时，可以沿第一表面54到第二表面55的方向依次冲压成型出各级刻痕槽532。在冲压成型多级刻痕槽532时，可以通过多次冲压对应形成多级刻痕槽532，每冲压一次成型一级刻痕槽532。刻痕槽532可以是多种形状的槽，比如，环形槽、弧形槽、U形槽、H形槽等。
泄压区56为外壳部件5在薄弱区52被破坏后能够打开的区域。最远离第一表面54的一级刻痕槽532位于泄压区56的边缘位置，在泄压区56打开过程中，薄弱区52沿着最远离第一表面54的一级刻痕槽532裂开，从而实现泄压区56以最远离第一表面54的一级刻痕槽532为边界打开。
薄弱区52形成于最远离于第一表面54的一级刻痕槽532的底部，最远离于第一表面54的一级刻痕槽532为最深位置(最内侧)的一级刻痕槽532。在相邻的两级刻痕槽532中，远离第一表面54的一级刻痕槽532设置于靠近第一表面54的一级刻痕槽532的底面。外壳部件5在最远离第一表面54的一级刻痕槽532的槽底面与第二表面55之间的部分为最远离第一表面54的一级刻痕槽532的槽底壁，该槽底壁即为薄弱区52。最远离第一表面54的一级刻痕槽532的槽底面即为槽部的槽底面531。最远离第一表面54的一级刻痕槽532即为最内侧的一级刻痕槽532b，最靠近第一表面54的一级刻痕槽532即为最外侧的一级刻痕槽532a。
作为示例，最外侧的一级刻痕槽532a的最大宽度为X，X≤10mm。最外侧的一级刻痕槽532a的最宽位置的宽度即为最外侧的一级刻痕槽532a的最大宽度。
在成型时，可以在外壳部件5上逐级成型多级刻痕槽532，可以降低每级刻痕槽532的成型深度，从而降低外壳部件5在成型每级刻痕槽532时所受到的成型力，降低外壳部件5产生裂纹的风险，外壳部件5不易因在设置刻痕槽532的位置产生裂纹而失效，提高了外壳部件5的使用寿命。
在一些实施例中，请参照图16、图18、图20，最远离第二表面55的一级刻痕槽532从第一表面54向靠近第二表面55的方向凹陷。
以槽部53中的刻痕槽532为两级为例，两级刻痕槽532分别为第一级刻痕槽和第二级刻痕槽。第一级刻痕槽设置于第一表面54，即第一级刻痕槽从第一表面54向靠近第二表面55的方向凹陷，第二级刻痕槽设置于第一级刻痕槽的槽底面；即第二级刻痕槽从第一级刻痕槽的槽底面向靠近第二表面55的方向凹陷。第一级刻痕槽为最外侧的一级刻痕槽532a，第二级刻痕槽为最内侧的一级刻痕槽532b。
槽部53由多级刻痕槽532构成，在成型时，可以从第一表面54到第二表面55的方向逐渐加工出多级刻痕槽532，成型效率高。
在一些实施例中，请参照图21-图27，图21为本申请一些实施例提供的外壳部件5的轴测图；图22为图21所示的外壳部件5的结构示意图(示出一级刻痕槽532和一级沉槽533)；图23为图22所示的外壳部件5的O-O剖视图；图24为本申请再一些实施例提供的外壳部件5的结构示意图(示出一级刻痕槽532和一级沉槽533)；图25为图24所示的外壳部件5的P-P剖视图；图26为本申请另一些实施例提供的外壳部件5的结构示意图(示出一级刻痕槽532和一级沉槽533)；图27为图26所示的外壳部件5的Q-Q剖视图。外壳部件5包括相对设置的第一表面54和第二表面55，槽部53还包括一级沉槽533，沉槽533从第一表面54向靠近第二表面55的方向凹陷，泄压区56形成于沉槽的槽底壁5331。
需要说明的是，无论槽部53中的刻痕槽532是一级，还是多级，槽部53中均可以包括一级沉槽533。可理解的，槽部53中既有刻痕槽532，又有沉槽533，槽部53为多级槽。沉槽533和刻痕槽532沿第一表面54到第二表面55的方向设置。在成型时，可以先在外壳部件5上成型沉槽533，然后，再在沉槽的槽底壁5331上成型刻痕槽532。沉槽533可以通过多种方式成型于外壳部件5，比如，冲压成型、铣削加工成型、激光刻蚀成型等。
沉槽的槽底壁5331为外壳部件5位于沉槽533的槽底面以下的部分，在第一表面54上成型沉槽533后，外壳部件5在设置沉槽533的区域的残留部分即为沉槽的槽底壁5331。如图23、图25、图27所示，外壳部件5位于沉槽533的槽底面与第二表面55之间的部分为沉槽的槽底壁5331。其中，泄压区56可以是沉槽的槽底壁5331的一部分。
沉槽533的设置，在保证最终的薄弱区52的厚度一定的情况下，可以降低刻痕槽532的深度，从而降低外壳部件5在成型刻痕槽532时所受到的成型力，降低外壳部件5产生裂纹的风险。此外，沉槽533能够为泄压区56在打开过程中提供避让空间，即使第一表面54被障碍物遮挡，泄压区56仍然能够打开泄压。
在一些实施例中，请参照图28-33，图28为本申请一些实施例提供的外壳部件5的结构示意图(示出一级刻痕槽532和两级沉槽533)；图29为图28所示的外壳部件5的R-R剖视图；图30为本申请再一些实施例提供的外壳部件5的结构示意图(示出一级刻痕槽532和两级沉槽533)；图31为图30所示的外壳部件5的S-S剖视图；图32为本申请另一些实施例提供的外壳部件5的结构示意图(示出一级刻痕槽532和两级沉槽533)；图33为图32所示的外壳部件5的T-T剖视图。外壳部件5包括相对设置的第一表面54和第二表面55，槽部53还包括多级沉槽533，多级沉槽533沿第一表面54到第二表面55的方向依次设置于外壳部件5，最远离第二表面55的一级沉槽533从第一表面54向靠近第二表面55凹陷，泄压区56形成于最远离第一表面54的一级沉槽的槽底壁5331。
需要说明的是，无论槽部53中的刻痕槽532是一级，还是多级，槽部53中均可以包括多级沉槽533。可理解的，槽部53中既有刻痕槽532，又有沉槽533，槽部53为多级槽。沉槽533和刻痕槽532沿第一表面54到第二表面55的方向设置。在成型时，可以先在外壳部件5上成型多级沉槽533，然后，再在最远离第一表面54的一级沉槽的槽底壁5331上成型刻痕槽532。
最远离第二表面55(最靠近第一表面54)的一级沉槽533为最外侧的一级沉槽533a，最远离第一表面54的一级沉槽533为最内侧的一级沉槽533b。最外侧的一级沉槽533a设置于第一表面54，最外侧的一级沉槽533a从第一表面54向靠近第二表面55凹陷。
最远离第一表面54的一级沉槽的槽底壁5331为外壳部件5位于最远离第一表面54的一级沉槽533的槽底面以下的部分，在外壳部件5上成型多级沉槽533后，外壳部件5在设置最远离第一表面54的一级沉槽533的区域的残留部分即为沉槽的槽底壁5331。如图29、图31、图33所示，外壳部件5位于最远离第一表面54的一级沉槽533的槽底面与第二表面55之间的部分为最远离第一表面54的一级沉槽的槽底壁5331。其中，泄压区56可以是最远离第一表面54的一级沉槽的槽底壁5331的一部分。
槽部53中的沉槽533可以是两级、三级、四级或者更多。在相邻的两级沉槽533中，远离第一表面54的一级沉槽533设置于靠近第一表面54的一级沉槽533的底面。沿第一表面54到第二表面55的方向，多级沉槽533的槽底面的轮廓逐级减小。各级沉槽533可以通过多种方式成型于外壳部件5，比如，冲压成型、铣削加工成型、激光刻蚀成型等。以各级沉槽533通过冲压成型的方式成型于外壳部件5为例，在成型时，可以沿第一表面54到第二表面55的方向依次冲压成型出各级沉槽533，再冲压成型刻痕槽532。以槽部53中的沉槽533为两级，刻痕槽532为一级为例，在冲压成型时，可以先进行两次冲压，以对应形成两级沉槽533，再进行一次冲压，以对应形成一级刻痕槽532。作为示例，在图28-33中，槽部53中的沉槽533为两级。
在成型多级沉槽533时，能够减小每级沉槽533的成型深度，能够降低成型每级沉槽533时外壳部件5受到的成型力，降低外壳部件5产生裂纹的风险。此外，多级沉槽533能够为泄压区56在打开过程中提供避让空间，即使第一表面54被障碍物遮挡，泄压区56仍然能够打开泄压。
在一些实施例中，沉槽533的内部空间为圆柱体、棱柱体、圆台体或棱台体。
沉槽533的内部空间为沉槽533的槽侧面和槽底面共同限定出来的空间。其中，棱柱体可以是三棱柱、四棱柱、五棱柱、六棱柱等；棱台体可以是三棱台、四棱台、五棱台或六棱台等。作为示例，在图21-33中，槽部53的内部空间为四棱柱，具体的，槽部53的内部空间为长方体。
在本实施例中，沉槽533结构简单，易于成型，能够为泄压区56在打开过程中提供更多地避让空间。
在一些实施例中，请参照图34，图34为本申请一些实施例提供的外壳部件5的结构示意图(示出一级刻痕槽532，刻痕槽532为V形)。刻痕槽532包括第一槽段5321和第二槽段5322，第一槽段5321与第二槽段5322相交，第一槽段5321和第二槽段5322沿着泄压区56的边缘设置。
第一槽段5321和第二槽段5322可以是直线形槽，也可以是非直线形槽，比如，圆弧形槽。在第一槽段5321和第二槽段5322均为直线形槽的实施例中，可理解的，第一槽段5321和第二槽段5322均沿直线延伸，第一槽段5321和第二槽段5322可以呈锐角、直角或钝角设置。第一槽段5321和第二槽段5322可以交叉设置，比如，第一槽段5321和第二槽段5322相交位置位于第一槽段5321的中点位置和第二槽段5322的中点位置；如图34所示，也可以是第一槽段5321和第二槽段5322的相交位置位于第一槽段5321的一端和第二槽段5322的一端，第一槽段5321和第二槽段5322构成V形结构，刻痕槽532为V形。
在本实施例中，第一槽段5321和第二槽段5322相交位置应力更为集中，使得薄弱区52能够在第一槽段5321与第二槽段5322相交的位置最先被破坏。在电池单体10的起爆压力一定的情况下，薄弱区52可以做得更厚，减小刻痕槽532的成型深度。
在一些实施例中，请参照图9、图15、图22和图28，刻痕槽532还可以包括第三槽段5323，第一槽段5321和第三槽段5323相对设置，第二槽段5322与第三槽段5323相交，第一槽段5321、第二槽段5322和第三槽段5323沿着泄压区56的边缘设置。
第一槽段5321、第二槽段5322和第三槽段5323均可以是直线形槽，也可以是非直线形槽，比如，圆弧形槽。在第一槽段5321、第二槽段5322和第三槽段5323均为直线形槽的实施例中，可理解的，第一槽段5321、 第二槽段5322和第三槽段5323均沿直线延伸，第一槽段5321与第三槽段5323两者可以平行设置，两者也可以呈夹角设置。第一槽段5321和第三槽段5323两者可以与第二槽段5322垂直，两者也可以与第二槽段5322不垂直。
第二槽段5322与第一槽段5321的连接位置可以位于第一槽段5321的一端，也可以位于偏离第一槽段5321的一端的位置，比如，第二槽段5322与第一槽段5321的连接位置位于第一槽段5321在延伸方向的中点位置；第二槽段5322与第三槽段5323的连接位置可以位于第三槽段5323的一端，也可以位置偏离第三槽段5323的一端的位置，比如，第二槽段5322与第三槽段5323的连接位置位于第三槽段5323在延伸方向的中点位置。
需要说明的是，在槽部53包括多级刻痕槽532的实施例中，可理解的，在相邻的两级刻痕槽532中，远离第一表面54的一级刻痕槽532的第一槽段5321设置于靠近第一表面54的一级刻痕槽532的第一槽段5321的槽底面；远离第一表面54的一级刻痕槽532的第二槽段5322设置于靠近第一表面54的一级刻痕槽532的第二槽段5322的槽底面；远离第一表面54的一级刻痕槽532的第三槽段5323设置于靠近第一表面54的一级刻痕槽532的第三槽段5323的槽底面。
在本实施例中，泄压区56能够以第一槽段5321、第二槽段5322和第三槽段5323为边界打开，在电池单体10泄压时，泄压区56打开更加容易，实现外壳部件5的大面积泄压。
在一些实施例中，请继续参照图9、图15、图22和图28，第一槽段5321、第二槽段5322和第三槽段5323限定出两个泄压区56，两个泄压区56分别位于第二槽段5322的两侧。
作为示例，第一槽段5321、第二槽段5322和第三槽段5323形成H形刻痕槽532，第二槽段5322与第一槽段5321的连接位置位于第一槽段5321的中点位置，第三槽段5323与第二槽段5322的连接位置位于第三槽段5323的中点位置。两个泄压区56对称设置于第二槽段5322的两侧，可理解的，两个泄压区56的面积相等。在其他实施例中，两个泄压区56也可以非对称地设置于第二槽段5322的两侧，使得两个泄压区56的面积不等，比如，第一槽段5321和第三槽段5323均垂直于第二槽段5322，第二槽段5322与第一槽段5321的连接位置偏离第一槽段5321的中点位置，和/或，第三槽段5323与第二槽段5322的连接位置位于第三槽段5323的中点位置。
两个泄压区56分别位于第二槽段5322的两侧，使得两个泄压区56以第二槽段5322分界，外壳部件5在第二槽段5322的位置破裂后，两个泄压区56能够沿着第一槽段5321和第三槽段5323以对开的形式打开，以实现泄压，可有效提高外壳部件5的泄压效率。
在另一些实施例中，第一槽段5321、第二槽段5322和第三槽段5323依次连接，第一槽段5321、第二槽段5322和第三槽段5323限定出一个泄压区56。
第一槽段5321、第二槽段5322和第三槽段5323依次连接可以形成U形刻痕槽532。
在一些实施例中，刻痕槽532为沿非封闭轨迹延伸的槽。
非封闭轨迹是指在延伸方向上的两端未相连的轨迹，非封闭轨迹可以是弧形轨迹、U形轨迹等。
在本实施例中，刻痕槽532为沿非封闭轨迹的槽，泄压区56可以以翻转的方式打开，泄压区56打开后最终与外壳部件5的其他区域相连，降低泄压区56打开后发生飞溅的风险。
在一些实施例中，请参照图11、图17、图24和图30所示，刻痕槽532为圆弧形槽。
圆弧形槽为沿圆弧形轨迹延伸的槽，圆弧形轨迹为非封闭轨迹。圆弧形槽的圆心角可以小于、等于或大于180°。
圆弧形槽结构简单，易于成型。在泄压过程中，泄压区56能够沿着圆弧形槽快速破裂，以使泄压区56快速打开。
在一些实施例中，请参照图13、图19、图26和图32，刻痕槽532为沿封闭轨迹延伸的槽。
封闭轨迹是指首尾两端相连的轨迹，封闭轨迹可以是圆形轨迹、矩形轨迹等。
在泄压过程中，外壳部件5能够沿刻痕槽532破裂，使得泄压区56可以以脱离的方式打开，增大了外壳部件5的泄压面积，提高外壳部件5的泄压速率。
在一些实施例中，刻痕槽532为环形槽。
环形槽可以是矩形环槽，也可以是圆形环槽。
环形槽结构简单，易于成型，在泄压过程中，外壳部件5可以沿着环形槽快速破裂，以使泄压区56快速打开。
在一些实施例中，泄压区56的面积为D，满足：90mm 2≤D≤1500mm 2。
在图9、图11、图13、图15、图17、图19、图22、图24、图26、图28、图30、图32和图34中，阴影部分的面积为泄压区56的面积。
需要说明的是，在槽部53中包括多级刻痕槽532的实施例中，泄压区56的面积为最深位置(最内侧)的一级刻痕槽532所限定出的区域的面积。
D可以是90mm 2、95mm 2、100mm 2、150mm 2、200mm 2、250mm 2、300mm 2、350mm 2、400mm 2、450mm 2、500mm 2、550mm 2、600mm 2、650mm 2、700mm 2、750mm 2、800mm 2、900mm 2、950mm 2、1000mm 2、1050mm 2、1100mm 2、1150mm 2、1200mm 2、1250mm 2、1300mm 2、1350mm 2、1400mm 2、1450mm 2、1500mm 2中任意一者点值或者任意两者之间的范围值。
当D＜90mm 2时，外壳部件5的泄压面积较小，电池单体10热失控时的泄压及时性较差；D＞1500mm 2，泄压区56的抗冲击能力较差，泄压区56受力后的变形增大，薄弱区52在电池单体10正常使用条件下容易被破坏，影响电池单体10的使用寿命。因此，90mm 2≤D≤1500mm 2，既能够提高电池单体10的使用寿命，又能够提高电池单体10的安全性。
进一步地，150mm 2≤D≤1200mm 2。使得外壳部件5的综合性能更优，在使得外壳部件5具有较大的泄压面积，且有较好的抗冲击能力。
进一步地，200mm 2≤D≤1000mm 2。
进一步地，250mm 2≤D≤800mm 2。
在一些实施例中，请参照图4-图34，外壳部件5具有相对设置的第一表面54和第二表面55，槽部53从第一表面54向靠近第二表面55的方向凹陷，槽部53在第一表面54形成外边缘534，外壳部件5距离外边缘534预设距离以外的区域为非薄弱区51。其中，预设距离为L。
L可以是1mm、2mm、3mm、4mm、5mm、6mm、7mm、8mm、9mm、10mm等。
在图9-图14所示的实施例中，槽部53仅包括一级刻痕槽532，刻痕槽532设置于第一表面54，刻痕槽532的槽侧面与第一表面54相交形成外边缘534，刻痕槽532的槽侧面围设在刻痕槽532的槽底面的周围。需要说明的是，在图13所示的实施例中，由于刻痕槽532为沿封闭轨迹延伸的槽，刻痕槽532的槽侧面与第一表面54相交形成内环线和位于内环线外侧的外环线，外环线为外边缘534。
在图15-图20所示的实施例中，槽部53仅包括多级刻痕槽532，最外侧的一级刻痕槽532a设置于第一表面54，最外侧的一级刻痕槽532a的槽侧面与第一表面54相交形成外边缘534。需要说明的是，在图19所示的实施例中，由于刻痕槽532为沿封闭轨迹延伸的槽，最外侧的一级刻痕槽532a与第一表面54相交形成内环线和位于内环线外侧的外环线，外环线为外边缘534。
在图21-图27所示的实施例中，槽部53还包括一级沉槽533，沉槽533设置于第一表面54，沉槽533的槽侧面与第一表面54相交形成外边缘534，沉槽533的槽侧面围设于沉槽533的槽底面的周围。在图28-图33所示的实施例中，槽部53还包括多级沉槽533，最外侧的一级沉槽533a设置与第一表面54，最外侧的一级沉槽533a的槽侧面与第一表面54相交形成外边缘534。
可理解的，外边缘534与非薄弱区51的内边缘511之间的距离为预设距离L，非薄弱区51的内边缘511的形状可以与外边缘534的形状基本相同。预设距离L所在方向可以与非薄弱区51的厚度方向垂直，也就是说，预设距离L可以沿着垂直于非薄弱区51的厚度方向测量。在测量非薄弱区51的平均晶粒尺寸时，可以在距离外边缘534以外的区域进行测量。
在本实施例中，外壳部件5距离外边缘534预设距离以外的区域为非薄弱区51，非薄弱区51与槽部53相距一定距离，非薄弱区51不易受到在成型槽部53的过程中的影响，使得非薄弱区51的晶粒更加均匀。
在一些实施例中，L＝5mm。
需要说明的是，如图9和图15所示，在刻痕槽532的第一槽段5321与第三槽段5323相对设置的实施例中，以第一槽段5321和第三槽段5323平行为例，当第一槽段5321与第三槽段5323之间的间距大于2*L时，非薄弱区51的内边缘511局部位于泄压区56，使得泄压区56部分位于非薄弱区51。在其他实施例中，请参照图35，图35为本申请其他实施例提供的外壳部件5的结构示意图，当第一槽段5321与第三槽段5323之间的间距小于或等于2*L，非薄弱区51的内边缘511并未位于泄压区56，非薄弱区51的内边缘511大致呈矩形。沿第一槽段5321的宽度方向，第一槽段5321与非薄弱区51的内边缘511的间距为L；沿第一槽段5321的长度方向，第一槽段5321与非薄弱区51的内边缘511的间距为L；沿第三槽段5323的宽度方向，第三槽段5323与非薄弱区51的内边缘511的间距为L；沿第三槽段5323的长度方向，第三槽段5323与非薄弱区51的内边缘511的间距为L。
在一些实施例中，请参照图36，图36为本申请另一些实施例提供的外壳部件5的晶粒图(示意图)。外壳部件5还包括过渡区57，过渡区57连接薄弱区52和非薄弱区51，过渡区57的平均晶粒尺寸为S 3，满足：S 3≤S 2。
作为示例，S 3＞S 1。
过渡区57为外壳部件5连接薄弱区52和非薄弱区51的部分，过渡区57环绕设置于薄弱区52的外侧， 非薄弱区51环绕在过渡区57的外侧，薄弱区52、过渡区57和非薄弱区51一体成型。
过渡区57的平均晶粒尺寸可以从非薄弱区51到薄弱区52逐渐减小。作为示例，如图36所示，以槽部53包括一级沉槽533和一级刻痕槽532为例，过渡区57位于沉槽533的外侧区域的平均晶粒尺寸可以大于过渡区57位于沉槽533的底部区域的平均晶粒尺寸，过渡区57位于沉槽533的外侧区域的平均晶粒尺寸可以小于或等于非薄弱区51的平均晶粒尺寸S 2，过渡区57位于沉槽533的底部区域的平均晶粒尺寸可以大于薄弱区52的平均晶粒尺寸S 1。
在本实施例中，过渡区57起到连接薄弱区52和非薄弱区51的作用，实现薄弱区52和非薄弱区51一体成型。
在一些实施例中，请参照图37，图37为本申请一些实施例提供的端盖11的结构示意图。外壳部件5为端盖11，端盖11用于封闭壳体12的开口，壳体12用于容纳电极组件2。
可理解的，端盖11设置有槽部53，以对应形成薄弱区52和非薄弱区51。外壳部件5的第一表面54和第二表面55分别为端盖11在厚度方向上相对的两个表面，即第一表面54和第二表面55中的一者为端盖11在厚度方向上的内表面，另一者为端盖11在厚度方向上的外表面。
端盖11可以是圆形、矩形板状结构。
作为示例，在图37示出的实施例中，端盖11为矩形板状结构。
在本实施例中，端盖11具有泄压功能，保证电池单体10的安全性。
在一些实施例中，请参照图38和图39，图38为本申请一些实施例提供的壳体12的结构示意图；图39为本申请另一些实施例提供的壳体12的结构示意图。外壳部件5为壳体12，壳体12具有开口，壳体12用于容纳电极组件2。
在本实施例中，外壳1的壳体12为外壳部件5，外壳1的端盖11用于封闭壳体12的开口。壳体12可以是一端形成开口的空心结构，也可以是相对的两端形成开口的空心结构。壳体12可以是长方体、圆柱体等。
在本实施例中，外壳部件5为壳体12，使得壳体12具有泄压功能，保证电池单体10的安全性。
在一些实施例中，壳体12包括一体成型的多个壁部121，多个壁部121共同限定出壳体12的内部空间，至少一个壁部121设置有槽部53。
在壳体12中，可以是一个壁部121上设置槽部53，以在该壁部121上对应形成一体成型的薄弱区52和非薄弱区51；也可以是多个壁部121上设置槽部53，以在设置槽部53的每个壁部121上形成一体成型的薄弱区52和非薄弱区51。对于设置有槽部53的壁部121而言，外壳部件5的第一表面54和第二表面55分别为壁部121在厚度方向上相对的两个表面，即第一表面54和第二表面55中的一者为壁部121在厚度方向上的内表面，另一者为壁部121在厚度方向上的外表面。
在本实施例中，多个壁部121一体成型，使得设置槽部53的壁部121具有更好的可靠性。
在一些实施例中，请继续参照图38和图39，多个壁部121包括底壁121b和围设于底壁121b的周围的多个侧壁121a，壳体12在与底壁121b相对的一端形成开口。底壁121b设置有槽部53；和/或，至少一个侧壁121a设置有槽部53。
在本实施例中，壳体12为一端形成开口的空心结构。壳体12中的侧壁121a可以是三个、四个、五个、六个或者更多。可以是一个、两个、三个、四个、五个、六个或者更多侧壁121a设置有槽部53。
作为示例，在图38中，仅一个侧壁121a设置有槽部53，以在该侧壁121a上对应形成薄弱区52和非薄弱区51；在图39中，仅底壁121b设置有槽部53，以在底壁121b上对应形成薄弱区52和非薄弱区51。
在一些实施例中，请继续参照图38和图39，壳体12为长方体。
可理解的，壳体12中的侧壁121a为四个。
长方体壳体适用于方形电池单体，能够满足电池单体10的大容量要求。
在一些实施例中，外壳部件5的材质包括铝合金。
铝合金的外壳部件5重量轻，具有很好的延展性，具有很好的塑性变形能力，易于成型。
在0.1≤S 1/S 2≤0.5的实施例中，由于铝合金具有很好的延展性，在通过冲压的方式在外壳部件5上成型槽部53时，更容易将S 1/S 2控制在0.5以下(包括0.5)，成型优率更高。
在一些实施例中，铝合金包括以下质量百分含量的成分：铝≥99.6％，铜≤0.05％，铁≤0.35％，镁≤0.03％，锰≤0.03％，硅≤0.25％，钛≤0.03％，钒≤0.05％，锌≤0.05％，其他单个元素≤0.03％。这种铝合金硬度更低，具有更好的成型能力，降低槽部53的成型难度，提高了槽部53的成型精度，提高了外壳部件5的泄压一致 性。
在一些实施例中，铝合金包括以下质量百分含量的成分：铝≥96.7％，0.05％≤铜≤0.2％，铁≤0.7％，锰≤1.5％，硅≤0.6％，锌≤0.1％，其他单个元素成分≤0.05％，其他元素总成分≤0.15％。由这种铝合金制成的外壳部件5硬度更高，强度大，具有良好的抗破坏能力。
本申请实施例提供一种电池单体10，包括上述任意一个实施例提供的外壳部件5。
在一些实施例中，电池单体10还包括壳体12，壳体12具有开口，壳体12用于容纳电极组件2。外壳部件5为端盖11，端盖11封闭开口。
在一些实施例中，外壳部件5为壳体12，壳体12具有开口，壳体12用于容纳电极组件2。电池单体10还包括端盖11，端盖11封闭开口。
本申请实施例提供一种电池100，包括上述任意一个实施例提供的电池单体10。
在一些实施例中，请参照图40，图40为本申请一些实施例提供的电池单体10的结构示意图，薄弱区52位于电池单体10的下部。
在电池单体10中，沿电池单体10的外壳1的高度方向，电池单体10位于外壳1的中平面Y以下的部分即为电池单体10的下部，其中，中平面Y垂直于外壳1的高度方向，中平面Y到外壳1在高度方向上的两端面的距离相等。比如，外壳1包括壳体12和端盖11，端盖11封闭壳体12的开口。壳体12和端盖11沿外壳1的高度方向排布，沿外壳1的高度方向，中平面Y位于端盖11背离壳体12的外表面与壳体12背离端盖11的外表面的中间位置。
薄弱区52位于电池单体10的下部，则槽部53位于电池单体10的下部，薄弱区52和槽部53均位于中平面Y的下方。薄弱区52可以位于壳体12，薄弱区52也可以位于端盖11。薄弱区52可以位于壳体12的侧壁121a，也可以位于壳体12的底壁121b。如图40所示，以薄弱区52位于壳体12的侧壁121a为例，可以是壳体12的底壁121b位于端盖11的下方，薄弱区52位于中平面Y以下，使得薄弱区52到壳体12的底壁121b的距离大于薄弱区52到端盖11的距离。
由于薄弱区52位于电池单体10的下部，在电池100使用过程中，在电池单体10内部的电极组件2、电解液等的重力作用下，薄弱区52会受到较大的作用力，由于薄弱区52与非薄弱区51为一体成型结构，具有很好的结构强度，具有更好的可靠性，提高电池单体10的使用寿命。
在一些实施例中，电池单体10包括壳体12，壳体12用于容纳电极组件2，壳体12包括一体成型的底壁121b和围设于底壁121b的周围的多个侧壁121a，底壁121b与侧壁121a一体成型，壳体12在与底壁121b相对的一端形成开口，薄弱区52位于底壁121b。
可理解的，底壁121b位于中平面Y的下方。
在本实施例中，薄弱区52位于底壁121b，使得薄弱区52朝下设置，在电池单体10热失控时，薄弱区52被破坏后，电池单体10中的排放物将朝下喷出，降低发生安全事故的风险。比如，在车辆1000中，电池100一般安装于乘客舱的下方，薄弱区52朝下设置，使得电池单体10热失控排出的排放物向背离乘客舱的方向喷出，降低排放物对乘客舱的影响，降低发生安全事故的风险。
在一些实施例中，电池单体10包括端盖11，端盖11用于封闭壳体12的开口，壳体12用于容纳电极组件2，薄弱区52位于端盖11。
可理解的，端盖11位于中平面Y的下方。
在本实施例中，薄弱区52位于端盖11，使得薄弱区52朝下设置，在电池单体10热失控时，薄弱区52被破坏后，电池单体10中的排放物将朝下喷出，降低发生安全事故的风险。
本申请实施例提供一种用电设备，包括上述任意一个实施例提供的电池100。
在一些实施例中，本申请实施例提供一种端盖11，用于电池单体10，端盖11包括一体成型的非薄弱区51和薄弱区52。端盖11设置槽部53，非薄弱区51形成于槽部53的周围，薄弱区52形成于槽部53的底部，薄弱区52被配置为在电池单体10泄放内部压力时被破坏。端盖11具有背离电池单体10的内部的第一表面54，槽部53在第一表面54形成外边缘534，端盖11距离外边缘534预设距离以外的区域为非薄弱区51，预设距离为L，L＝5mm。薄弱区52的平均晶粒尺寸为S 1，非薄弱区51的平均晶粒尺寸为S 2，薄弱区52的最小厚度为A，非薄弱区51的最小厚度为B，薄弱区52的硬度为H 1，非薄弱区51的硬度为H 2，满足：0.1≤S 1/S 2≤0.5，5≤A/S 1≤20，190HBW/mm≤H 1/A≤4000HBW/mm，1＜H 1/H 2≤2.5，0.2≤A/B≤0.5。
在一些实施例中，本申请实施例提供一种壳体12，用于电池单体10，壳体12包括一体成型的非薄弱区51和薄弱区52。壳体12设置槽部53，非薄弱区51形成于槽部53的周围，薄弱区52形成于槽部53的底部，薄弱区52被配置为在电池单体10泄放内部压力时被破坏。壳体12具有背离电池单体10的内部的第一表面54，槽部 53在第一表面54形成外边缘534，壳体12距离外边缘534预设距离以外的区域为非薄弱区51，预设距离为L，L＝5mm。薄弱区52的平均晶粒尺寸为S 1，非薄弱区51的平均晶粒尺寸为S 2，薄弱区52的最小厚度为A，非薄弱区51的最小厚度为B，薄弱区52的硬度为H 1，非薄弱区51的硬度为H 2，满足：0.1≤S 1/S 2≤0.5，5≤A/S 1≤20，190HBW/mm≤H 1/A≤4000HBW/mm，1＜H 1/H 2≤2.5，0.2≤A/B≤0.5。
以下结合实施例对本申请的特征和性能作进一步的详细描述。
在各实施例和对比例中，电池单体10为方形电池单体，电池单体10中的端盖11作为外壳部件5，电池单体10的容量为150Ah，化学体系为NCM。
一、测试方法
(1)薄弱区52和非薄弱区51的平均晶粒尺寸测试。
薄弱区52和非薄弱区51的平均晶粒尺寸测试采用电子背散射衍射(EBSD)法。将外壳部件5切开成3段，中间段两端的截面都有薄弱区52和非薄弱区51。切割方向与薄弱区52长度方向垂直，切割设备不改变晶粒结构。选择中间段进行取样，然后将样品进行电解抛光后，将试样固定在倾斜70°的样品台上，选择合适的放大倍数，使用安装有电子背散射衍射(EBSD)附件的扫描电子显微镜(SEM)进行EBSD扫描，根据扫描结果，最后计算出平均晶粒尺寸(即检验面内完整晶粒的等积圆直径)。
(2)薄弱区52和非薄弱区51的最小厚度测试。
将外壳部件5切开成3段，取中间段作为试样，试样两端的截面都有薄弱区52和非薄弱区51。切割方向与薄弱区52长度方向垂直。对中间段截面进行抛光充分去除毛刺后，将试样放置在三次元坐标量测仪，对截面上的薄弱区52和非薄弱区51进行厚度测量。
(3)薄弱区52和非薄弱区51的硬度测试。
将外壳部件5切开成3段，取中间段作为试样，试样两端的截面都有薄弱区52和非薄弱区51。切割方向与薄弱区52长度方向垂直，对试验截面进行抛光充分去除毛刺后，将试样水平放置(试样截面方向与硬度测量仪挤压方向平行)在布氏硬度测量仪上进行硬度测量。若薄弱区52宽度尺寸<1mm或布氏硬度测量仪的压头尺寸远大于薄弱区52宽度，应按照布氏硬度测量和换算原理，加工非标压头进行硬度测量。
(4)薄弱区52在电池单体10正常使用条件下的开裂率。
将电池单体10放置在25±2℃条件下，进行循环充放电，充放电区间5％-97％SOC，同时监控电池单体10内部产气气压，同时进行500组试验。试验截止条件为：电池单体10寿命下降至80％SOH或任意一组电池单体10在循环过程中薄弱区52开裂。其中，薄弱区52开裂判定条件为：电池单体10内部气压值下降，其下降值>最大气压的10％。统计薄弱区52的开裂率，开裂率＝开裂数量/总数量*100％。
(5)电池单体10在热失控时的爆炸率。
在电池单体10内内置一个小型加热膜，给加热膜通电，给电池单体10加热，直至电池单体10发生热失控，观察电池单体10是否爆炸。重复进行500组试验，统计电池单体10的爆炸率，爆炸率＝爆炸的数量/总数量*100％。
二、测试结果
在各实施例和对比例中，薄弱区52的平均晶粒尺寸S 1、非薄弱区51的平均晶粒尺寸S 2、薄弱区52的最小厚度A、非薄弱区51的最小厚度B、薄弱区52的硬度H 1、非薄弱区51的硬度H 2的测试结果如表一所示，在表一中，S 1和S 2的单位为mm，A和B的单位为mm，H 1和H 2的单位为HBW；薄弱区52在电池单体10正常使用条件下的开裂率Q 1和电池单体10在热失控时的爆炸率Q 2如表二所示。
表一
Figure PCTCN2022132665-appb-000001
Figure PCTCN2022132665-appb-000002
Figure PCTCN2022132665-appb-000003
Figure PCTCN2022132665-appb-000004
表二
  Q 1 Q 2
实施例1 8.8％ 0.6％
实施例2 6.8％ 0.8％
实施例3 6.2％ 1.4％
实施例4 5％ 1.6％
实施例5 2.8％ 2.8％
实施例6 0.8％ 4.2％
实施例7 0.6％ 8.4％
实施例8 0.4％ 8％
实施例9 1.2％ 4％
实施例10 2.6％ 1.8％
实施例11 3.2％ 1.4％
实施例12 6％ 1％
实施例13 10.2％ 0.6％
实施例14 6.2％ 1.8％
实施例15 3.8％ 3.8％
实施例16 2.4％ 6.6％
实施例17 1％ 8.8％
实施例18 0.8％ 12％
实施例19 1.2％ 10％
实施例20 1.8％ 4.4％
实施例21 2.4％ 2.2％
实施例22 6％ 1.4％
实施例23 8％ 1％
实施例24 1％ 14.2％
实施例25 1.4％ 9.2％
实施例26 2.2％ 8％
实施例27 3％ 3.6％
实施例28 3.6％ 1.6％
实施例29 5％ 1％
实施例30 7.4％ 0.4％
实施例31 10.4％ 0.4％
对比例1 20.2％ 0.6％
对比例2 22.4％ 0.4％
对比例3 26.4％ 0.4％
结合表一和表二，根据实施例1～7可知，在S 1/S 2≤0.9时，薄弱区52在电池单体10正常使用条件下开裂率较低。在对比例1中，0.9＜S 1/S 2＜1，薄弱区52在电池单体10正常使用条件下开裂率明显升高；在对比例2中，S 1/S 2＝1，薄弱区52在电池单体10正常使用条件下开裂率明显升高；在对比例3中，S 1/S 2＞1，薄弱区52在电池单体10正常使用条件下开裂率也明显升高。比较实施例1～7和对比例1～3可知，将S 1/S 2控制在不超过0.9，能够有效降低薄弱区52在电池单体10正常使用条件下被破坏的风险，从而提高电池单体10的使用寿命。
根据实施例7可知，当S 1/S 2＜0.05时，薄弱区52在电池单体10热失控时被破坏的难度增大，泄压不及时，电池单体10发生爆炸的风险明显增大。从实施例3～5可以看出，当0.1≤S 1/S 2≤0.5时，薄弱区52在电池单体10正常使用条件下的开裂率以及电池单体10在热失控时的爆炸率均较低，保证薄弱区52在电池单体10热失控时能够及时被破坏的情况下，保证薄弱区52在电池单体10正常使用条件下具有足够的强度。
从实施例9～12与实施例8比较可以看出，当1≤A/S 1≤100时，电池单体10在热失控时能够及时泄压，电池单体10爆炸率较低。当5≤A/S 1≤20时，电池单体10的综合性能更优，薄弱区52在电池单体10正常使用条件下的开裂率以及电池单体10在热失控时的爆炸率均较低。
从实施例14～17与实施例13比较可以看出，当H 1/A＞10000HBW/mm时，薄弱区52在电池单体10正常使用条件下的开裂率较高，比较实施例14～17和实施例18可知，当H 1/A＜5HBW/mm时，电池单体10在热失控时的爆炸率较高。而5HBW/mm≤H 1/A≤10000HBW/mm，既能够降低薄弱区52在电池单体10正常使用条件下破裂的风险，又能够在电池单体10热失控时通过薄弱区52及时泄压，降低电池单体10发生爆炸的风险。从实施例15～16可以看出，当190HBW/mm≤H 1/A≤4000HBW/mm时，电池单体10的综合性能更优，薄弱区52在电池单体10正常使用条件下的开裂率以及电池单体10在热失控时的爆炸率均较低。
从实施例19～21与实施例22～23比较可以看出，当H 1/H 2≤1时，薄弱区52在电池单体10正常使用条件下的开裂率较高。而H 1/H 2＞1能够有效降低薄弱区52在电池单体10正常使用条件下的开裂率。比较实施例20～21和实施例19可知，当H 1/H 2＞5时，电池单体10在热失控时的爆炸率较高。而H 1/H 2≤5能够降低电池单体10发生爆炸的风险。
从实施例25～30与实施例24比较可以看出，当A/B＞0.95时，电池单体10在热失控时的爆炸率较高。比较实施例25～30和实施例31可知，当A/B＜0.05时，薄弱区52在电池单体10正常使用条件下的开裂率较高。而0.05≤A/B≤0.95，既能够降低薄弱区52在电池单体10正常使用条件下破裂的风险，又能够在电池单体10热失控时通过薄弱区52及时泄压，降低电池单体10发生爆炸的风险。从实施例26～29可以看出，当0.12≤A/B≤0.8时，电池单体10的综合性能更优，薄弱区52在电池单体10正常使用条件下的开裂率以及电池单体10在热失控时的爆炸率均较低，0.2≤A/B≤0.5，效果更优。
需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互组合。
以上实施例仅用以说明本申请的技术方案，并不用于限制本申请，对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。

Claims (50)

  1. 一种外壳部件，用于电池单体，包括一体成型的非薄弱区和薄弱区，所述外壳部件设置有槽部，所述非薄弱区形成于所述槽部的周围，所述薄弱区形成于所述槽部的底部，所述薄弱区被配置为在所述电池单体泄放内部压力时被破坏；
    其中，所述薄弱区的平均晶粒尺寸为S 1，所述非薄弱区的平均晶粒尺寸为S 2，满足：S 1/S 2≤0.9。
  2. 根据权利要求1所述的外壳部件，其中，S 1/S 2≥0.05。
  3. 根据权利要求1或2所述的外壳部件，其中，0.1≤S 1/S 2≤0.5。
  4. 根据权利要求1-3任一项所述的外壳部件，其中，0.4μm≤S 1≤75μm；优选地，1μm≤S 1≤10μm。
  5. 根据权利要求1-4任一项所述的外壳部件，其中，10μm≤S 2≤150μm；优选地，30μm≤S 2≤100μm。
  6. 根据权利要求1-5任一项所述的外壳部件，其中，所述薄弱区的最小厚度为A，满足：1≤A/S 1≤100；优选地，5≤A/S 1≤20。
  7. 根据权利要求1-6任一项所述的外壳部件，其中，所述薄弱区的最小厚度为A，所述薄弱区的硬度为H 1，满足：5HBW/mm≤H 1/A≤10000HBW/mm；优选地，190HBW/mm≤H 1/A≤4000HBW/mm。
  8. 根据权利要求7所述的外壳部件，其中，0.02mm≤A≤1.6mm；优选地，0.06mm≤A≤0.4mm。
  9. 根据权利要求1-8任一项所述的外壳部件，其中，所述薄弱区的硬度为H 1，所述非薄弱区的硬度为H 2，满足：H 1＞H 2。
  10. 根据权利要求9所述的外壳部件，其中，H 1/H 2≤5；优选地，H 1/H 2≤2.5。
  11. 根据权利要求9或10所述的外壳部件，其中，5HBW≤H 2≤150HBW。
  12. 根据权利要求7-11任一项所述的外壳部件，其中，5HBW≤H 1≤200HBW。
  13. 根据权利要求1-12任一项所述的外壳部件，其中，所述薄弱区的最小厚度为A，所述非薄弱区的最小厚度为B，满足：0.05≤A/B≤0.95；优选地，0.12≤A/B≤0.8；优选地，0.2≤A/B≤0.5。
  14. 根据权利要求13所述的外壳部件，其中，0.02mm≤A≤1.6mm；优选地，0.06mm≤A≤0.4mm。
  15. 根据权利要求13或14所述的外壳部件，其中，1mm≤B≤5mm；优选地，1.2mm≤B≤3.5mm；优选地，2mm≤B≤3mm。
  16. 根据权利要求1-15任一项所述的外壳部件，其中，所述外壳部件具有泄压区，所述槽部包括一级刻痕槽，所述刻痕槽沿着所述泄压区的边缘设置，所述泄压区被配置为能够以所述刻痕槽为边界打开，所述薄弱区形成所述刻痕槽的底部。
  17. 根据权利要求16所述的外壳部件，其中，所述外壳部件具有相对设置的第一表面和第二表面，所述刻痕槽从所述第一表面向靠近所述第二表面的方向凹陷。
  18. 根据权利要求1-15任一项所述的外壳部件，其中，所述外壳部件包括相对设置的第一表面和第二表面，所述槽部包括多级刻痕槽，多级所述刻痕槽沿所述第一表面到所述第二表面的方向依次设置于所述外壳部件，所述薄弱区形成于最远离所述第一表面的一级所述刻痕槽的底部；
    其中，所述外壳部件具有泄压区，每级所述刻痕槽沿着所述泄压区的边缘设置，所述泄压区被配置为能够以最远离所述第一表面的一级所述刻痕槽为边界打开。
  19. 根据权利要求18所述的外壳部件，其中，最远离所述第二表面的一级所述刻痕槽从所述第一表面向靠近所述第二表面的方向凹陷。
  20. 根据权利要求16或18所述的外壳部件，其中，所述外壳部件包括相对设置的第一表面和第二表面，所述槽部还包括一级沉槽，所述沉槽从所述第一表面向靠近所述第二表面的方向凹陷，所述泄压区形成于所述沉槽的槽底壁。
  21. 根据权利要求16或18所述的外壳部件，其中，所述外壳部件包括相对设置的第一表面和第二表面，所述槽部还包括多级沉槽，多级所述沉槽沿所述第一表面到所述第二表面的方向依次设置于外壳部件，最远离所述第二表面的一级所述沉槽从所述第一表面向靠近所述第二表面凹陷，所述泄压区形成于最远离所述第一表面的一级所述沉槽的槽底壁。
  22. 根据权利要求20或21所述的外壳部件，其中，所述沉槽的内部空间为圆柱体、棱柱体、圆台体或棱台体。
  23. 根据权利要求16-22任一项所述的外壳部件，其中，所述刻痕槽包括第一槽段和第二槽段，所述第一槽段与所述第二槽段相交，所述第一槽段和所述第二槽段沿着所述泄压区的边缘设置。
  24. 根据权利要求23所述的外壳部件，其中，所述刻痕槽还包括第三槽段，所述第一槽段和所述第三槽段相对设置，所述第二槽段与所述第三槽段相交，所述第一槽段、所述第二槽段和所述第三槽段沿着所述泄压区的边缘设置。
  25. 根据权利要求24所述的外壳部件，其中，所述第一槽段、所述第二槽段和所述第三槽段依次连接，所述第一槽段、所述第二槽段和所述第三槽段限定出一个所述泄压区。
  26. 根据权利要求24所述的外壳部件，其中，所述第一槽段、所述第二槽段和所述第三槽段限定出两个所述泄压区，两个所述泄压区分别位于所述第二槽段的两侧。
  27. 根据权利要求16-22任一项所述的外壳部件，其中，所述刻痕槽为沿非封闭轨迹延伸的槽。
  28. 根据权利要求16-22及27任一项所述的外壳部件，其中，所述刻痕槽为圆弧形槽。
  29. 根据权利要求16-22任一项所述的外壳部件，其中，所述刻痕槽为沿封闭轨迹延伸的槽。
  30. 根据权利要求16-22及29任一项所述的外壳部件，其中，所述刻痕槽为环形槽。
  31. 根据权利要求16-30任一项所述的外壳部件，其中，所述泄压区的面积为D，满足：90mm 2≤D≤1500mm 2；优选地，150mm 2≤D≤1200mm 2；优选地，200mm 2≤D≤1000mm 2；优选地，250mm 2≤D≤800mm 2。
  32. 根据权利要求1-31任一项所述的外壳部件，其中，所述外壳部件具有相对设置的第一表面和第二表面，所述槽部从所述第一表面向靠近所述第二表面的方向凹陷，所述槽部在所述第一表面形成外边缘，所述外壳部件距离所述外边缘预设距离以外的区域为所述非薄弱区。
  33. 根据权利要求32所述的外壳部件，其中，所述预设距离为L，满足：L＝5mm。
  34. 根据权利要求1-33任一项所述的外壳部件，其中，所述外壳部件还包括过渡区，所述过渡区连接所述薄弱区和所述非薄弱区，所述过渡区的平均晶粒尺寸为S 3，满足：S 3≤S 2。
  35. 根据权利要求1-34任一项所述的外壳部件，其中，所述外壳部件为端盖，所述端盖用于封闭壳体的开口，所述壳体用于容纳电极组件。
  36. 根据权利要求1-34任一项所述的外壳部件，其中，所述外壳部件为壳体，所述壳体具有开口，所述壳体用于容纳电极组件。
  37. 根据权利要求36所述的外壳部件，其中，所述壳体包括一体成型的多个壁部，多个所述壁部共同限定出所述壳体的内部空间，至少一个所述壁部设置有所述槽部。
  38. 根据权利要求37所述的外壳部件，其中，所述多个壁部包括底壁和围设于所述底壁的周围的多个侧壁，所述壳体在与所述底壁相对的一端形成所述开口；
    所述底壁设置有所述槽部；和/或
    至少一个所述侧壁设置有所述槽部。
  39. 根据权利要求36-38任一项所述的外壳部件，其中，所述壳体为长方体。
  40. 根据权利要求1-39任一项所述的外壳部件，其中，所述外壳部件的材质包括铝合金。
  41. 根据权利要求40所述的外壳部件，其中，所述铝合金包括以下质量百分含量的成分：铝≥99.6％，铜≤0.05％，铁≤0.35％，镁≤0.03％，锰≤0.03％，硅≤0.25％，钛≤0.03％，钒≤0.05％，锌≤0.05％，其他单个元素≤0.03％。
  42. 根据权利要求40所述的外壳部件，其中，所述铝合金包括以下质量百分含量的成分：铝≥96.7％，0.05％≤铜≤0.2％，铁≤0.7％，锰≤1.5％，硅≤0.6％，锌≤0.1％，其他单个元素成分≤0.05％，其他元素总成分≤0.15％。
  43. 一种电池单体，包括：
    如权利要求1-42任一项所述的外壳部件。
  44. 根据权利要求43所述的电池单体，其中，所述电池单体还包括壳体，所述壳体具有开口，所述壳体用于容纳电极组件；
    所述外壳部件为端盖，所述端盖封闭所述开口。
  45. 根据权利要求43所述的电池单体，其中，所述外壳部件为壳体，所述壳体具有开口，所述壳体用于容纳电极组件；
    所述电池单体还包括端盖，所述端盖封闭所述开口。
  46. 一种电池，包括权利要求43-45任一项所述的电池单体。
  47. 根据权利要求46所述的电池，其中，所述薄弱区位于所述电池单体的下部。
  48. 根据权利要求47所述的电池，其中，所述电池单体包括壳体，所述壳体用于容纳电极组件，所述壳体包括底壁和围设于所述底壁的周围的多个侧壁，所述底壁与所述侧壁一体成型，所述壳体在与所述底壁相对的一端形成开口，所述薄弱区位于所述底壁。
  49. 根据权利要求47所述的电池，其中，所述电池单体包括端盖，端盖用于封闭壳体的开口，所述壳体用于容纳电极组件，所述薄弱区位于所述端盖。
  50. 一种用电设备，包括权利要求46-49任一项所述的电池。
PCT/CN2022/132665 2022-11-17 2022-11-17 外壳部件、电池单体、电池及用电设备 WO2024103355A1 (zh)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN215989102U (zh) * 2021-08-31 2022-03-08 宁德时代新能源科技股份有限公司 泄压装置、电池单体、电池及用电设备
CN215989098U (zh) * 2021-07-21 2022-03-08 宁德时代新能源科技股份有限公司 电池单体、电池以及用电装置
CN114231796A (zh) * 2021-12-14 2022-03-25 大力神铝业股份有限公司 一种用于电池防爆阀的铝合金材料及其制备方法
CN217719870U (zh) * 2022-06-02 2022-11-01 宁德时代新能源科技股份有限公司 泄压装置、外壳、电池单体、电池及用电设备

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CN215989098U (zh) * 2021-07-21 2022-03-08 宁德时代新能源科技股份有限公司 电池单体、电池以及用电装置
CN215989102U (zh) * 2021-08-31 2022-03-08 宁德时代新能源科技股份有限公司 泄压装置、电池单体、电池及用电设备
CN114231796A (zh) * 2021-12-14 2022-03-25 大力神铝业股份有限公司 一种用于电池防爆阀的铝合金材料及其制备方法
CN217719870U (zh) * 2022-06-02 2022-11-01 宁德时代新能源科技股份有限公司 泄压装置、外壳、电池单体、电池及用电设备

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