Battery cell, battery, and electric device

Abstract

A battery cell (10), a battery (100), and an electric device. The battery cell (10) comprises a casing (1) and a pressure relief component (6); the casing (1) comprises a first wall portion (13); the pressure relief component (6) is provided on the first wall portion (13); the pressure relief component (6) comprises a first groove (61); the first groove (61) defines at least one predetermined pressure relief area (63); and the pressure relief component (6) is configured to be capable of cracking along at least part of the first groove (61) when the battery cell (10) undergoes pressure relief. The pressure relief component (6) further comprises a groove group (62); the groove group (62) is in one-to-one correspondence with the predetermined pressure relief area (63); each groove group (62) comprises a plurality of second grooves (621); the plurality of second grooves (621) are arranged at intervals in the width direction of the second grooves (621); and the second grooves (621) are configured to guide at least part of the predetermined pressure relief area (63) to flip so as to open the at least part of the predetermined pressure relief area (63). The plurality of second grooves (621) all can help the predetermined pressure relief area (63) to flip, such that flipping of the predetermined pressure relief area (63) is easier, the flipping difficulty of the predetermined pressure relief area (63) is reduced, and the risk of fire or explosion during thermal runaway of the battery cell (10) is reduced, thereby improving the reliability of the battery cell (10).

Description

Battery cells, batteries and electrical equipment Technical Field

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

[0002] New energy vehicles have experienced rapid growth in recent years. Within the electric vehicle sector, power batteries, as the power source, play an irreplaceable and crucial role. With the widespread adoption of new energy vehicles, demand for power batteries is also growing. This increasing demand for batteries places higher demands on the reliability of battery cells. Therefore, improving the reliability of battery cells is a pressing challenge in battery technology.

[0003] Summary of the Invention

[0004] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can effectively improve the reliability of the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, comprising a shell and a pressure relief component, the shell comprising a first wall portion, the pressure relief component being arranged on the first wall portion, the pressure relief component comprising a first groove, the first groove defining at least one predetermined pressure relief area, the pressure relief component being configured to be able to split along at least a portion of the first groove when the battery cell releases pressure; wherein, the pressure relief component further comprises a groove group, the groove group corresponding one-to-one to the predetermined pressure relief area, each groove group comprising a plurality of second grooves, the plurality of second grooves being spaced apart along the width direction of the second groove, the second groove being configured to guide at least a portion of the predetermined pressure relief area to flip so as to open at least a portion of the predetermined pressure relief area.

[0006] In the above technical solution, the pressure relief component includes a first groove, which enables the pressure relief component to rupture along at least a portion of the first groove when the battery cell releases pressure, thereby releasing the internal pressure of the battery cell. The pressure relief component also includes a groove group, which corresponds one-to-one to the predetermined pressure relief area. Each groove group includes a plurality of second grooves, and the plurality of second grooves are spaced along the width direction of the second groove. The plurality of second grooves in the groove group can help flip the predetermined pressure relief area, making it easier to flip the predetermined pressure relief area, reducing the difficulty of flipping the predetermined pressure relief area, and enabling the predetermined pressure relief area to open more quickly when the pressure relief component ruptures along the first groove, thereby reducing the risk of fire or explosion in the event of thermal runaway of the battery cell, thereby effectively improving the reliability of the battery cell.

[0007] In some embodiments, the predetermined pressure relief zone has an open end and a non-open end, the open end and the non-open end are arranged relative to each other along the width direction of the second groove, and the minimum residual thickness of the plurality of second grooves in the groove group gradually decreases in the direction from the non-open end to the open end. Among the plurality of second grooves, each second groove can help the portion of the predetermined pressure relief zone located between the second groove and the open end to flip, so that the portion of the predetermined pressure relief zone located between the second groove and the open end can flip around the residual portion of the second groove. Since the minimum residual thickness of the plurality of second grooves gradually decreases in the direction from the non-open end to the open end, it is beneficial to achieve that the portion of the predetermined pressure relief zone located between a second groove near the open end and the open end flips earlier than the portion of the predetermined pressure relief zone located between a second groove far from the open end and the open end.

[0008] In some embodiments, the maximum groove depth of the plurality of second grooves in the groove group gradually increases from the non-open end to the open end. During production, the plurality of second grooves in the groove group can be processed in a sequence in which the depth gradually increases from the non-open end to the open end, thereby achieving a gradual decrease in the minimum residual thickness of the plurality of second grooves in the groove group from the non-open end to the open end.

[0009] In some embodiments, the minimum residual thickness of the first groove is smaller than the minimum residual thickness of the second groove, so that the strength of the residual portion of the first groove is smaller than the strength of the residual portion of the second groove, so that the pressure relief component can preferentially break along the first groove to achieve rapid opening of the predetermined pressure relief area.

[0010] In some embodiments, the minimum residual thickness of the first groove is D1, 0.1 mm ≤ D1 ≤ 0.5 mm. D1 ≥ 0.1 mm ensures that the residual portion of the first groove has sufficient strength, reducing the risk of the pressure relief component prematurely cracking along the first groove during long-term cycling of the battery cell, thereby increasing the service life of the battery cell. D1 ≤ 0.5 mm allows the pressure relief component to crack along the first groove more promptly in the event of thermal runaway of the battery cell, reducing the risk of fire or explosion of the battery cell.

[0011] In some embodiments, the maximum groove depth of the first groove is greater than the maximum groove depth of the second groove. During the production process, the depth of the first groove can be machined deeper than the depth of the second groove, which reduces the difficulty of achieving a minimum residual thickness of the first groove that is smaller than the minimum residual thickness of the second groove.

[0012] In some embodiments, the first groove has two ends, a line connecting the two ends is a first line, the first groove and the first line are connected and together enclose a predetermined pressure relief area; the predetermined pressure relief area has an open end and a closed end, the first line is located at the closed end, the open end and the closed end are arranged opposite each other along the width direction of the second groove, and at least one second groove in the groove group is located in the predetermined pressure relief area along the thickness direction of the first wall portion, and is located between the open end and the closed end along the width direction of the second groove, and the width direction of the second groove is perpendicular to the thickness direction of the first wall portion. In this way, at least two areas of the predetermined pressure relief area are flipped, thereby reducing the area swept by the predetermined pressure relief area during flipping, reducing the flipping space required for the predetermined pressure relief area, reducing the risk of interference between the predetermined pressure relief area and external components, and improving the reliability of the battery cell.

[0013] In some embodiments, the projection of at least one second groove in the groove group along the thickness direction of the first wall portion does not overlap with the projection of the predetermined pressure relief zone along the thickness direction of the first wall portion. At least one second groove is located outside the predetermined pressure relief zone, so that a larger area of ​​the predetermined pressure relief zone can be flipped when the battery cell thermal runaway occurs, thereby increasing the opening area of ​​the predetermined pressure relief zone. In addition, the second groove located outside the predetermined pressure relief zone can absorb the excess material squeezed out when the first groove is formed, thereby improving the flatness of the outer surface of the shell in the width direction of the second groove. The second groove located outside the predetermined pressure relief zone of the second groove can also block the deformation energy of the shell when the shell is subjected to internal and external impact forces, thereby reducing the risk of the predetermined pressure relief zone opening prematurely due to the expansion of the battery cell.

[0014] In some embodiments, at least one second groove in the groove group is a first guide groove. The projection of the first guide groove along the thickness direction of the first wall does not overlap with the projection of the predetermined pressure relief zone along the thickness direction of the first wall. The first guide groove and the first groove are spaced apart along the width direction of the first guide groove. The projection of the first guide groove along the thickness direction of the first wall extends beyond the two ends of the first groove along the extension direction. This makes the first guide groove longer and enhances the first guide groove's ability to assist in the flipping of the predetermined pressure relief zone. Furthermore, this structure can enhance the first guide groove's ability to separate the surface of the housing along the width direction of the first guide groove from the first groove, improve the first guide groove's ability to absorb excess material extruded during the molding of the first groove, further improve the flatness of the housing's outer surface along the width direction of the first guide groove, and enhance the first guide groove's ability to block deformation energy when the housing is subjected to internal or external impact forces, further reducing the risk of battery cell expansion leading to premature opening of the predetermined pressure relief zone.

[0015] In some embodiments, all second grooves in the groove group are located in the predetermined pressure relief zone along the thickness direction of the first wall portion and are located between the open end and the closed end along the width direction of the second groove. This allows more of the predetermined pressure relief zone to be flipped, further reducing the area swept by the predetermined pressure relief zone during flipping and reducing the flipping space required for the predetermined pressure relief zone.

[0016] In some embodiments, along the thickness direction of the first wall portion, the projection of the second groove does not overlap with the projection of the first groove, thereby reducing the mutual influence between the first groove and the second groove during the processing and lowering the risk of the first groove and the second groove communicating with each other during the processing.

[0017] In some embodiments, the first groove defines a plurality of predetermined pressure relief areas. In the event of thermal runaway of the battery cell, the plurality of predetermined pressure relief areas can all be opened. Given a given total pressure relief area of ​​the pressure relief component, the opening rate of the predetermined pressure relief areas can be increased, allowing for faster pressure relief.

[0018] In some embodiments, the first wall is a rectangular wall, and the plurality of second grooves in the slot assembly are spaced apart along the width of the first wall. When the first wall deforms due to expansion of the battery cells, the deformation of the first wall in the width direction is less than that in the length direction. Spacing the plurality of second grooves in the slot assembly along the width of the first wall can reduce the impact of deformation of the first wall on the second grooves, thereby reducing the risk of fatigue cracking of the pressure relief component along the second grooves during the normal cycle life of the battery cells.

[0019] In some embodiments, the pressure relief component has a first surface and a second surface facing each other along the thickness direction of the first wall portion. The first groove is recessed from the first surface toward the second surface, and the second groove is recessed from the second surface toward the first surface. The first groove and the second groove are located on opposite sides of the pressure relief component along the thickness direction of the first wall portion, respectively. This facilitates machining the first groove and the second groove on both sides of the pressure relief component, thereby minimizing mutual influence between the first groove and the second groove during machining.

[0020] In some embodiments, the pressure relief component has a first surface and a second surface facing each other along the thickness direction of the first wall portion, and the first groove and the second groove are both recessed from the first surface toward the second surface. Thus, the first groove and the second groove are disposed on the same side of the pressure relief component in the thickness direction, making it easier to machine the first groove and the second groove on the pressure relief component. The first groove and the second groove can be machined without flipping the pressure relief component, thereby optimizing the production cycle of battery cells.

[0021] In some embodiments, the first surface is the surface of the pressure relief component facing the outside of the battery cell, and the second surface is the surface of the pressure relief component facing the inside of the battery cell. When the first groove is provided on the first surface, the first groove is provided on the outside of the pressure relief component, which facilitates the processing and forming of the first groove on the outside of the shell, which is conducive to reducing the difficulty of forming the first groove and improving the production efficiency of the battery cell. When the second groove is provided on the first surface, the second groove is provided on the outside of the pressure relief component, which facilitates the processing and forming of the second groove on the outside of the shell, which is conducive to reducing the difficulty of forming the second groove. When the second groove is provided on the second surface, the second groove is provided on the inside of the pressure relief component. On the one hand, when the predetermined pressure relief area is flipped outward and opened, the two groove sides in the width direction of the second groove are not easily abutted, which is conducive to increasing the opening area of ​​the predetermined pressure relief area; on the other hand, the second groove is not exposed to the outside of the battery cell, reducing the risk of oxidation and corrosion of the pressure relief component in the second groove area.

[0022] In some embodiments, the first groove comprises a plurality of grooves arranged sequentially along a direction pointing from the first surface to the second surface, and along the thickness direction of the first wall portion, in two adjacent grooves, the first groove farther from the first surface is arranged at the bottom surface of the first groove closer to the first surface. By arranging the first grooves as a plurality of grooves along the thickness direction of the first wall portion, when forming the first groove, each groove level can be processed one by one along a direction pointing from the first surface to the second surface, thereby reducing the forming depth of each groove level, reducing the forming force applied to the pressure relief component during the forming of the first groove, and reducing the risk of damage to the pressure relief component during the forming of the first groove.

[0023] In some embodiments, the first groove includes multiple groove segments, which are connected to each other and together define at least one predetermined pressure relief area. The multiple groove segments can define a larger predetermined pressure relief area, which is beneficial for increasing the pressure relief area of ​​the battery cell.

[0024] In some embodiments, the plurality of groove segments include a first groove segment and a second groove segment, the first groove segment being connected to the second groove segment, and the first groove segment and the second groove segment jointly defining at least one predetermined pressure relief area. The first groove of this structure is simple in structure, and the location where the first groove segment connects to the second groove segment has a greater stress concentration factor, is weaker, and is more prone to cracking. This allows the pressure relief component to quickly break away from the first and second groove segments after breaking away from the location where the first and second groove segments connect in the event of thermal runaway of the battery cell, allowing the predetermined pressure relief area to open more quickly and relieve pressure in a timely manner.

[0025] In some embodiments, the plurality of slot segments include a first slot segment, a second slot segment, and a third slot segment, the second slot segment and the third slot segment being arranged opposite each other, the plurality of second slots in the slot group being located on the same side of the first slot segment in the width direction, the first slot segment connecting the second slot segment and the third slot segment, and the first, second, and third slot segments collectively defining at least one predetermined pressure relief zone. The first slots of this structure weaken the intersection of the first and second slot segments and the connection between the first and third slot segments, making it easier to rupture and open the predetermined pressure relief zone for pressure relief, and further increasing the open area of ​​the predetermined pressure relief zone, thereby increasing the pressure relief area of ​​the battery cell and improving the pressure relief rate of the battery cell.

[0026] In some embodiments, the connection position between the second groove section and the first groove section is offset from both ends of the second groove section, and the connection position between the third groove section and the first groove section is offset from both ends of the third groove section, so that predetermined pressure relief areas are formed on both sides of the first groove section. In this way, the first groove section of the first groove is located between the two predetermined pressure relief areas. After the pressure relief component is split along the first groove section, the two predetermined pressure relief areas can open in a split manner to relieve pressure when the battery cell releases pressure. This allows the two predetermined pressure relief areas to open quickly, which is beneficial for improving the pressure relief rate of the battery cell.

[0027] In some embodiments, the groove segments extend along straight or curved paths. If the groove segments extend along straight paths, the groove segments are linear, which can reduce the difficulty of forming the groove segments. If the groove segments extend along curved paths, the groove segments are curved, making it easier for the pressure relief component to break along the groove segments when the battery cell is depressurized, thereby achieving faster opening of the predetermined pressure relief area.

[0028] In some embodiments, the first groove extends along an arc-shaped track. The first groove of this structure only includes one groove segment, which simplifies the structure of the first groove.

[0029] In some embodiments, the second groove extends along a straight line. The second groove has a simple structure and is easy to process and form.

[0030] In some embodiments, the pressure relief component is integrally formed with the first wall portion, so that the first groove and the second groove can be directly formed on the first wall portion, forming an integrated pressure relief structure, which has higher reliability, eliminates the installation process of the pressure relief component, and has better economy.

[0031] In some embodiments, the first groove is stamped into the first wall; and / or the second groove is stamped into the first wall. If the first groove is stamped into the first wall, the first groove is formed in a simpler manner, which helps reduce the production cost of the battery cell. If the second groove is stamped into the first wall, the second groove is formed in a simpler manner, which helps reduce the production cost of the battery cell.

[0032] In some embodiments, the pressure relief component is separately provided with the first wall portion and is mounted on the first wall portion. The pressure relief component is a component independent of the housing, and the pressure relief component and the housing can be produced and assembled separately, which is easy to produce and efficient.

[0033] In some embodiments, the housing includes a shell and an end cap, wherein at least one end of the shell has an opening, and the end cap corresponds to the opening in a one-to-one manner, thereby sealing the opening. At least one end cap is a first wall portion. This allows the at least one end cap to have a pressure relief function, thereby reducing the difficulty of forming the first groove and the second groove on the end cap or installing the pressure relief component.

[0034] In some embodiments, the housing includes a shell and an end cap. The shell has an opening formed at least at one end, and the end cap corresponds to the opening in a one-to-one relationship, thereby sealing the opening. At least one wall portion of the shell is a first wall portion. This allows the shell to have a pressure relief function. When the battery cell is depressurized, the exhaust from the battery cell is less likely to affect external components outside the end cap, thereby reducing the risk of damage to the external components by the exhaust.

[0035] In some embodiments, the housing has an opening at only one end, and the wall of the housing opposite the end cap is the first wall. This single-end opening simplifies the overall battery cell structure. The first wall, the wall of the housing opposite the end cap, allows for directional pressure relief from the bottom of the housing.

[0036] In some embodiments, the housing has openings at both opposing ends. With openings at both ends, the electrode assembly can be assembled into the housing through either opening, reducing the difficulty of battery cell assembly and improving the assembly quality. This housing structure allows for a longer length (with openings at both ends), which helps increase the battery cell's capacity.

[0037] In some embodiments, the pressure relief component is made of steel. Steel has high strength, and the pressure relief component made of steel has better strength. Under a certain bursting pressure of the battery cell, the pressure relief component can be made thinner, reducing the volume of the pressure relief component.

[0038] In some embodiments, the steel material is carbon steel or stainless steel.

[0039] In some embodiments, the pressure relief component is made of aluminum alloy, which is lightweight and ductile, making it easier to machine the first groove and the second groove on the pressure relief component.

[0040] In some embodiments, the aluminum alloy includes the following composition by weight: aluminum ≥ 99.6%, copper ≤ 0.05%, iron ≤ 0.35%, magnesium ≤ 0.03%, manganese ≤ 0.03%, silicon ≤ 0.25%, titanium ≤ 0.03%, vanadium ≤ 0.05%, zinc ≤ 0.05%, and other individual elements ≤ 0.03%. This aluminum alloy has lower hardness and better formability, reduces the difficulty of machining the first and second grooves, improves the machining accuracy of the first and second grooves, and enhances the pressure relief consistency of the pressure relief component.

[0041] In some embodiments, the aluminum alloy includes the following composition by weight: aluminum ≥ 96.7%, copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other individual elements ≤ 0.05%, and other elements combined ≤ 0.15%. Pressure relief components made from this aluminum alloy have increased hardness, strength, and excellent damage resistance.

[0042] In a second aspect, an embodiment of the present application provides a battery, comprising a battery cell provided by any embodiment of the first aspect.

[0043] In a third aspect, an embodiment of the present application provides an electrical device, comprising a battery cell provided by any one embodiment of the first aspect, wherein the battery cell is used to provide electrical energy to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0045] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0046] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0047] FIG3 is an exploded view of a battery cell provided in some embodiments of the present application;

[0048] FIG4 is an assembly diagram of the battery cell shown in FIG3 ;

[0049] FIG5 is a partial view of the housing shown in FIG4 ;

[0050] FIG6 is a cross-sectional view taken along line AA of the housing shown in FIG5 ;

[0051] FIG7 is a partial enlarged view of point B in FIG6;

[0052] FIG8 is a cross-sectional view of the housing shown in FIG6 (with a portion of the predetermined pressure relief area opened);

[0053] FIG9 is a cross-sectional view of the housing shown in FIG6 (with the predetermined pressure relief area fully opened);

[0054] FIG10 is a partial view of a housing provided in some embodiments of the present application;

[0055] FIG11 is a cross-sectional view of a housing provided in some embodiments of the present application;

[0056] FIG12 is a partial view of a housing provided in some other embodiments of the present application;

[0057] FIG13 is a CC cross-sectional view of the housing shown in FIG12 ;

[0058] FIG14 is a partial enlarged view of point D in FIG13;

[0059] FIG15 is a partial view of a housing provided in some further embodiments of the present application;

[0060] FIG16 is a sectional view taken along line FF of the housing shown in FIG15 ;

[0061] FIG17 is a partial view of a housing provided in some other embodiments of the present application;

[0062] FIG18 is a cross-sectional view taken along line GG of the housing shown in FIG17 ;

[0063] FIG19 is an exploded view of a housing (an opening is formed at one end of the housing, and the end cover is a first wall portion) provided in some embodiments of the present application;

[0064] FIG20 is an exploded view of a housing (an opening is formed at one end of the housing, and the end cover is the first wall portion) provided in some other embodiments of the present application;

[0065] FIG21 is an exploded view of a housing (an opening is formed at one end of the housing, and the housing includes a first wall portion) provided in some embodiments of the present application;

[0066] FIG22 is an exploded view of a housing (an opening is formed at one end of the housing, and the housing includes a first wall portion) provided in some other embodiments of the present application;

[0067] FIG23 is an exploded view of a battery cell provided in some other embodiments of the present application.

[0068] Icons: 1-housing; 11-shell; 12-end cover; 13-first wall; 131-pressure relief hole; 14-second wall; 15-third wall; 2-electrode assembly; 21-tab; 3-electrode terminal; 4-current collecting member; 5-insulating member; 6-pressure relief component; 61-first groove; 611-slot section; 611a-first slot section; 611b-second slot section; 611c-third slot section; 62-slot group; 621-second groove; 621a-first guide groove; 63-predetermined pressure relief area; 631-opening end; 632-non-opening end; 64-first surface; 65-second surface; 10-battery cell; 20-housing; 201-first part; 202-second part; 100-battery; 200-controller; 300 - motor; 1000 - vehicle; W - first connecting line; X - thickness direction of the first wall; Y - length direction of the first wall; Z - width direction of the first wall. DETAILED DESCRIPTION

[0069] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0070] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0071] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0072] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0073] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0074] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0075] The term "plurality" used in this application refers to two or more (including two).

[0076] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0077] Battery cells include but are not limited to lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0078] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process, active ions (such as lithium ions) move back and forth between the positive and negative electrodes. A separator, placed between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0079] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0080] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0081] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0082] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include but are not limited to at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include but are not limited to lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05O2) and at least one of its modified compounds, etc.

[0083] In some embodiments, a positive electrode may be a metal foam. The metal foam may be nickel foam, copper foam, aluminum foam, or alloy foam, among others. When a metal foam is used as the positive electrode, the surface of the metal foam may or may not include a positive electrode active material. For example, a lithium source material, potassium metal, or sodium metal may be filled or / and deposited within the metal foam, where the lithium source material is lithium metal and / or a lithium-rich material.

[0084] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0085] As an example, the negative electrode current collector may be a metal foil, a metal foam, or a composite current collector. For example, the metal foil may be silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium. The metal foam may be nickel foam, copper foam, aluminum foam, or alloy foam. The composite current collector may include a polymer base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy, etc.) on a polymer substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0086] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0087] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0088] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells that is well known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0089] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0090] In some embodiments, the separator is a separator membrane, which can be any known porous separator membrane with good chemical and mechanical stability.

[0091] As an example, the separator can be made of at least one of fiberglass, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film. In the case of a multi-layer composite film, the materials of each layer can be the same or different. The separator can be a separate component positioned between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0092] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0093] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel, or solid. Liquid electrolytes include an electrolyte salt and a solvent.

[0094] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium bisoxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0095] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0096] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0097] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0098] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, or the like.

[0099] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0100] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0101] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0102] In some embodiments, the electrode assembly is a laminate structure.

[0103] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0104] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0105] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0106] As an example, a plurality of separators may be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0107] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0108] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0109] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0110] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0111] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. Prismatic battery cells include square-shell battery cells, blade-shaped battery cells, and polygonal prismatic batteries. Polygonal prismatic batteries are, for example, hexagonal prismatic batteries.

[0112] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0113] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0114] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0115] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0116] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0117] The development of battery technology must take into account multiple design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery safety must also be considered.

[0118] In order to improve the reliability of battery cells, a pressure relief component can generally be provided in the battery cells. The pressure relief component can be a part of the battery cell shell or a component installed on the shell. When the battery cell thermally runs away, the pressure inside the battery cell can be released through the pressure relief component.

[0119] For typical battery cells, a first groove can be provided on the pressure relief component, defining at least one predetermined pressure relief zone. When the pressure in the battery cell is released, the pressure relief component can rupture along at least a portion of the first groove, allowing the predetermined pressure relief zone of the pressure relief component to open and release pressure, thereby relieving the pressure within the battery cell. In such a battery cell, in the event of thermal runaway, the predetermined pressure relief zone becomes difficult to open during the rupture of the pressure relief component along the first groove, affecting the opening speed of the predetermined pressure relief zone and making it more likely that the battery cell will catch fire or explode, resulting in poor reliability.

[0120] Based on the above considerations, in order to solve the problem of poor reliability of the battery, an embodiment of the present application provides a battery cell, by arranging a slot group on the pressure relief component, the slot group corresponds one-to-one to the predetermined pressure relief area, each slot group includes a plurality of second grooves, and the plurality of second grooves are arranged at intervals along the width direction of the second grooves, and the second grooves are used to guide at least a portion of the predetermined pressure relief area to flip so as to open at least a portion of the predetermined pressure relief area.

[0121] In such a battery cell, the multiple second grooves in the slot group can help flip the predetermined pressure relief area, making the flipping of the predetermined pressure relief area easier and reducing the difficulty of flipping the predetermined pressure relief area, so that the predetermined pressure relief area can open more quickly when the pressure relief component is cracked along the first groove, reducing the risk of fire or explosion during thermal runaway of the battery cell, thereby effectively improving the reliability of the battery cell.

[0122] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0123] Electrically powered equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools. Vehicles can be fuel-powered, gas-powered, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles, or extended-range vehicles. Spacecraft include aircraft, rockets, space shuttles, and spacecraft. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers.

[0124] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0125] Please refer to Figure 1, which is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application. A battery 100 is disposed within vehicle 1000. Battery 100 can be located at the bottom, front, or rear of vehicle 1000. Battery 100 can be used to power vehicle 1000, for example, as an operating power source for vehicle 1000.

[0126] The vehicle 1000 may further include a controller 200 and a motor 300 . The controller 200 is used to control the battery 100 to supply power to the motor 300 , for example, to meet the power requirements of the vehicle 1000 during startup, navigation, and driving.

[0127] In some embodiments of the present application, the battery 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0128] Please refer to Figure 2, which is an exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a battery cell 10 and a housing 20, wherein the battery cell 10 is accommodated in the housing 20.

[0129] The housing 20 is a component that houses the battery cells 10 and provides a storage space for the battery cells 10. The housing 20 can have various structures. In some embodiments, the housing 20 can include a first portion 201 and a second portion 202, which overlap to define a storage space for the battery cells 10. The first portion 201 and the second portion 202 can have various shapes, such as a rectangular parallelepiped or a cylindrical shape. The first portion 201 can be a hollow structure with one side open, and the second portion 202 can also be a hollow structure with one side open. The open side of the second portion 202 overlaps the open side of the first portion 201, thereby forming the housing 20 with a storage space. Alternatively, the first portion 201 can be a hollow structure with one side open, and the second portion 202 can be a plate-like structure. The second portion 202 overlaps the open side of the first portion 201, thereby forming the housing 20 with a storage space. The first portion 201 and the second portion 202 can be sealed by a sealing element, which can be a sealing ring, sealant, etc.

[0130] In the battery 100, there can be one or more battery cells 10. If there are multiple battery cells 10, the multiple battery cells 10 can be connected in series, parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 10. Multiple battery cells 10 can be connected in series, parallel, or in a hybrid connection to form a battery module, which can then be connected in series, parallel, or in a hybrid connection to form a single unit and housed within the housing 20. Alternatively, all battery cells 10 can be directly connected in series, parallel, or in a hybrid connection, and then the entire unit formed by all battery cells 10 can be housed within the housing 20.

[0131] Please refer to Figure 3, which is an exploded view of a battery cell 10 provided in some embodiments of the present application. The battery cell 10 may include a housing 1 and an electrode assembly 2, wherein the electrode assembly 2 is accommodated in the housing 1.

[0132] In some embodiments, the housing 1 may include a shell 11 and an end cover 12 , wherein the shell 11 has an opening and the end cover 12 closes the opening of the shell 11 .

[0133] The housing 11 is a component for accommodating the electrode assembly 2. The housing 11 can be a hollow structure with an opening at one end, or a hollow structure with openings at opposite ends. The housing 11 can have various shapes, such as a cylinder or a rectangular parallelepiped. The housing 11 can be made of various materials, such as copper, iron, aluminum, steel, and aluminum alloys.

[0134] The end cap 12 is a component that closes the opening of the shell 11 to isolate the internal environment of the battery cell 10 from the external environment. The end cap 12 and the shell 11 together define a receiving space for accommodating the electrode assembly 2, electrolyte and other components. The end cap 12 can be connected to the shell 11 by welding or rolling to close the opening of the shell 11. The shape of the end cap 12 can be adapted to the shape of the shell 1. For example, the shell 11 is a rectangular parallelepiped structure, and the end cap 12 is a rectangular plate structure adapted to the shell 1. For another example, the shell 11 is a cylindrical structure, and the end cap 12 is a circular plate structure adapted to the shell 11. The material of the end cap 12 can also be a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, plastic, etc. The material of the end cap 12 and the shell 11 can be the same or different.

[0135] In an embodiment where the housing 11 is open at one end, one end cap 12 may be provided. In an embodiment where the housing 11 is open at two opposite ends, two end caps 12 may be provided, each of which closes the two openings of the housing 11, and the two end caps 12 and the housing 11 together define a receiving space.

[0136] In some embodiments, the battery cell 10 may further include an electrode terminal 3, which is disposed on the outer casing 1. The electrode terminal 3 is used to electrically connect to the tab 21 of the electrode assembly 2 to input or output electrical energy from the battery cell 10. The electrode terminal 3 may be disposed on the shell 11 of the outer casing 1 or on the end cap 12 of the outer casing 1. The electrode terminal 3 and the tab 21 may be directly connected, for example, by directly welding the electrode terminal 3 and the tab 21. The electrode terminal 3 and the tab 21 may also be indirectly connected, for example, by indirectly connecting the electrode terminal 3 and the tab 21 through a current collecting member 4. The current collecting member 4 may be a metal conductor, such as copper, iron, aluminum, steel, an aluminum alloy, or the like.

[0137] As an example, as shown in FIG3 , an opening is formed at one end of the housing 11. There is only one end cap 12 in the outer shell 1, and each end cap 12 closes the opening of the housing 11. Two electrode terminals 3 are provided on the end cap 12, namely a positive electrode terminal 3 and a negative electrode terminal 3. A positive electrode tab 21 and a negative electrode tab 21 are formed on the end of the electrode assembly 2 facing the end cap 12. The positive electrode terminal 3 and the positive electrode tab 21 are connected via a current collecting member 4, and the negative electrode terminal 3 and the negative electrode tab 21 are connected via another current collecting member 4.

[0138] 3 , the battery cell 10 may further include an insulating member 5 . The insulating member 5 is a component that separates the housing 11 from the electrode assembly 2 , thereby achieving insulation isolation between the housing 11 and the electrode assembly 2 . The insulating member 5 is made of an insulating material, including but not limited to plastic, rubber, and the like.

[0139] As an example, the insulating member 5 wraps around the outside of the electrode assembly 2 along the circumference of the opening of the housing 11. There can be one or more electrode assemblies 2 within the housing 1. If there is a single electrode assembly 2, the insulating member 5 wraps around it. If there are multiple electrode assemblies 2, one insulating member 5 can be provided for each electrode assembly 2, with each insulating member 5 wrapping around a single electrode assembly 2. Alternatively, multiple electrode assemblies 2 can be formed as a single integral component, with the insulating member 5 wrapping around the integral component.

[0140] Referring to Figures 4-7 , Figure 4 is an assembly diagram of the battery cell 10 shown in Figure 3 ; Figure 5 is a partial view of the housing 1 shown in Figure 4 ; Figure 6 is a cross-sectional view taken along line AA of the housing 1 shown in Figure 5 ; and Figure 7 is a partial enlarged view of point B in Figure 6 . This embodiment of the present application provides a battery cell 10 comprising a housing 1 and a pressure relief component 6 . The housing 1 comprises a first wall portion 13 , the pressure relief component 6 being disposed on the first wall portion 13 , and the pressure relief component 6 including a first groove 61 defining at least one predetermined pressure relief area 63 . The pressure relief component 6 is configured to rupture along at least a portion of the first groove 61 when pressure is released from the battery cell 10 .

[0141] The pressure relief component 6 also includes a groove group 62, which corresponds one-to-one to the predetermined pressure relief area 63. Each groove group 62 includes a plurality of second grooves 621, and the plurality of second grooves 621 are arranged at intervals along the width direction of the second groove 621. The second groove 621 is configured to guide at least a portion of the predetermined pressure relief area 63 to flip over to open at least a portion of the predetermined pressure relief area 63.

[0142] The outer shell 1 may include multiple walls, which together define a receiving space inside the outer shell 1 to accommodate the battery cells 10, electrolyte, and other components. The other components may be current collecting members 4, insulating members 5, and other components. Among the multiple walls of the outer shell 1, one wall may be the first wall 13, or multiple walls may be the first wall 13. Taking the outer shell 1 as an example of a rectangular parallelepiped, there are six walls in the outer shell 1, and one, two, three, four, five, or six walls may be the first wall 13. In the outer shell 1, at least one end cap 12 may be the first wall 13, or at least one wall in the shell 11 may be the first wall 13.

[0143] The pressure relief component 6 is a component within the battery cell 10 that relieves pressure within the battery cell 10. The pressure relief component 6 is disposed on the first wall portion 13. The pressure relief component 6 and the first wall portion 13 may be integrally formed, or they may be separate components, with the pressure relief component 6 being mounted on the first wall portion 13. If the pressure relief component 6 is integrally formed with the first wall portion 13, such that the pressure relief component 6 forms at least a portion of the first wall portion 13, the entire first wall portion 13 may serve as the pressure relief component 6, or a portion of the first wall portion 13 may serve as the pressure relief component 6.

[0144] The first groove 61 is a pressure relief groove provided in the pressure relief component 6. When the pressure inside the battery cell 10 reaches the burst pressure of the pressure relief component 6, the pressure relief component 6 can rupture along at least a portion of the first groove 61 to open a predetermined pressure relief area 63. It is understood that when the pressure inside the battery cell 10 is released, the pressure relief component 6 can rupture along the entire first groove 61 or along a portion of the first groove 61 to release the pressure inside the battery cell 10. The first groove 61 can be formed in various ways, such as by stamping or milling. The first groove 61 can include at least one groove segment 611. The cross-section of the groove segment 611 can have various shapes, such as rectangular or trapezoidal. The cross-section of the groove segment 611 is perpendicular to the direction of extension of the groove segment 611. The first groove 61 can have various shapes. For example, the first groove 61 can be a groove extending along an arcuate trajectory. For another example, the first groove 61 can include multiple groove segments 611. The multiple groove segments 611 can form a U-shape, H-shape, V-shape, Y-shape, X-shape, T-shape, etc.

[0145] The predetermined pressure relief area 63 is the area of ​​the pressure relief component 6 defined by the first groove 61. The predetermined pressure relief area 63 defined by the first groove 61 can be one or more. The predetermined pressure relief area 63 is capable of opening when the pressure relief component 6 is ruptured along the first groove 61. The predetermined pressure relief area 63 can be triangular, rectangular, trapezoidal, semicircular, or other shapes. In the embodiment shown in FIG5 , there are two predetermined pressure relief areas 63, and the two shaded areas represent the two predetermined pressure relief areas 63.

[0146] The multiple second grooves 621 in the slot group 62 are spaced apart, meaning that adjacent second grooves 621 are spaced a certain distance apart. For example, the multiple second grooves 621 in the slot group 62 are arranged in parallel. There may be two, three, four, or more second grooves 621 in the slot group 62. Each slot group 62 corresponds to a predetermined pressure relief area 63 on a one-to-one basis. For example, if there are two second grooves 621 in the slot group 62, each predetermined pressure relief area 63 corresponds to two second grooves 621. The second grooves 621 serve as turning grooves in the pressure relief component 6. When the pressure relief component 6 is ruptured along at least a portion of the first groove 61, the second grooves 621 guide at least a portion of the predetermined pressure relief area 63 to turn. In other words, the second grooves 621 facilitate the turning of the predetermined pressure relief area 63, making it easier for the predetermined pressure relief area 63 to turn toward the outside of the battery cell 10, thereby quickly opening the predetermined pressure relief area 63. The second grooves 621 may guide the turning of the predetermined pressure relief area 63 in its entirety or only in a portion. The flipped portion of the predetermined pressure relief area 63 can flip around the remaining portion of the second groove 621, and the remaining portion of the second groove 621 can be the bottom wall of the second groove 621. During the pressure relief process of the battery cell 10, the pressure relief component 6 can be cracked along at least a portion of the first groove 61, and generally will not be cracked along the second groove 621. The minimum residual thickness of the first groove 61 can be less than the minimum residual thickness of the second groove 621, so that the area of ​​the pressure relief component 6 where the first groove 61 is provided is easier to crack than the area of ​​the pressure relief component 6 where the second groove 621 is provided. The second groove 621 can be formed in a variety of ways, such as stamping, milling, etc. The shape of the second groove 621 can be various, for example, the second groove 621 is a groove extending along an arc trajectory, and for another example, the second groove 621 is a groove extending along a straight trajectory. The cross-sectional shape of the second groove 621 can be various, such as rectangular, trapezoidal, etc.

[0147] In the groove group 62, the projections of all the second grooves 621 along the thickness direction X of the first wall portion may be located within the predetermined pressure relief area 63, or the projections of all the second grooves 621 along the thickness direction X of the first wall portion may be located outside the predetermined pressure relief area 63, or the projections of some of the second grooves 621 along the thickness direction X of the first wall portion may be located within the predetermined pressure relief area 63, and the projections of another part of the second grooves 621 along the thickness direction X of the first wall portion may be located outside the predetermined pressure relief area 63.

[0148] The second groove 621 and the first groove 61 can be provided on the same surface of the pressure relief component 6 along the thickness direction X of the first wall portion, or the second groove 621 and the first groove 61 can be provided on two opposing surfaces of the pressure relief component 6 along the thickness direction X of the first wall portion. The multiple second grooves 621 in the groove group 62 can be provided on the same surface of the pressure relief component 6 along the thickness direction X of the first wall portion, or the multiple second grooves 621 in the groove group 62 can be provided on one surface of the pressure relief component 6 along the thickness direction X of the first wall portion, while the other portion can be provided on the other surface of the pressure relief component 6 along the thickness direction X of the first wall portion.

[0149] As an example, in the embodiment shown in Figures 4-7 , the wall portion of the housing 11 opposite the end cap 12 is the first wall portion 13. The first wall portion 13 serves as the pressure relief component 6. A first groove 61 and a second groove 621 are respectively provided on two opposing surfaces of the first wall portion 13 in the thickness direction. The first wall portion 13 is a rectangular wall portion, with the length direction Y, the width direction Z, and the thickness direction X of the first wall portion being perpendicular to each other. The first groove 61 is H-shaped, and the second groove 621 extends along a straight path. The second groove 621 extends in a direction parallel to the length direction Y of the first wall portion, and the width direction of the second groove 621 is parallel to the width direction Z of the first wall portion. The housing 11 may further include a second wall portion 14 and a third wall portion 15. The first wall portion 13 connects the second wall portion 14 and the third wall portion 15. The second wall portion 14 and the third wall portion 15 are disposed opposite each other along the width direction of the second groove 621. The housing 1 is in a rectangular parallelepiped shape, with a thickness direction X of the first wall portion parallel to the height direction of the battery cell 10 , a length direction Y of the first wall portion parallel to the length direction of the battery cell 10 , and a width direction Z of the first wall portion parallel to the thickness direction of the battery cell 10 .

[0150] In this embodiment, the pressure relief component 6 includes a first groove 61, which allows the pressure relief component 6 to rupture along at least a portion of the first groove 61 when the battery cell 10 releases pressure, thereby releasing the internal pressure of the battery cell 10. The pressure relief component 6 also includes groove groups 62, which correspond one-to-one to the predetermined pressure relief areas 63. Each groove group 62 includes a plurality of second grooves 621, which are spaced apart along the width of the second groove 621. The plurality of second grooves 621 in the groove group 62 can facilitate the flipping of the predetermined pressure relief area 63, making the flipping of the predetermined pressure relief area 63 easier and reducing the difficulty of flipping the predetermined pressure relief area 63. This allows the predetermined pressure relief area 63 to open more quickly when the pressure relief component 6 ruptures along the first groove 61, reducing the risk of fire or explosion in the event of thermal runaway of the battery cell 10, thereby effectively improving the reliability of the battery cell 10.

[0151] In some embodiments, please refer to Figures 5-7, the predetermined pressure relief area 63 has an open end 631 and a non-open end 632, and the open end 631 and the non-open end 632 are relatively arranged along the width direction of the second groove 621, and the minimum residual thickness of the multiple second grooves 621 in the groove group 62 gradually decreases in the direction from the non-open end 632 to the open end 631.

[0152] Along the width direction of the second groove 621 , the open end 631 is an end of the predetermined pressure relief area 63 that can be opened when the battery cell 10 releases pressure, and the non-open end 632 is an end of the predetermined pressure relief area 63 that is not opened when the battery cell 10 releases pressure.

[0153] The minimum residual thickness of the second groove 621 is the minimum thickness of the remaining portion of the pressure relief component 6 after the second groove 621 is provided. The remaining portion of the second groove 621 may be the bottom wall of the second groove 621. The thickness of the remaining portion of the second groove 621 may be uniform or uneven. If the thickness of the remaining portion of the second groove 621 is uneven, the thickness of the thinnest portion of the remaining portion of the second groove 621 is the minimum residual thickness of the second groove 621.

[0154] Taking the number of the second grooves 621 in the groove group 62 as an example, among the two second grooves 621 , the minimum residual thickness of the second groove 621 away from the open end 631 is greater than the minimum residual thickness of the second groove 621 close to the open end 631 .

[0155] Among the multiple second grooves 621, each second groove 621 can help the part of the predetermined pressure relief zone 63 located between the second groove 621 and the open end 631 to flip, so that the part of the predetermined pressure relief zone 63 located between the second groove 621 and the open end 631 can flip around the residual part of the second groove 621. Since the minimum residual thickness of the multiple second grooves 621 gradually decreases in the direction from the non-open end 632 to the open end 631, it is beneficial to achieve that the part of the predetermined pressure relief zone 63 located between a second groove 621 close to the open end 631 and the open end 631 flips earlier than the part of the predetermined pressure relief zone 63 located between a second groove 621 away from the open end 631 and the open end 631.

[0156] In some embodiments, the maximum groove depths of the plurality of second grooves 621 in the groove group 62 gradually increase in a direction from the non-open end 632 to the open end 631 .

[0157] The maximum distance between the opening of the second groove 621 and the bottom surface of the second groove 621 along the thickness direction X of the first wall portion is the maximum groove depth of the second groove 621. As an example, the sum of the maximum groove depth of the second groove 621 and the minimum residual thickness of the second groove 621 is equal to the thickness of the first wall portion 13.

[0158] Taking the case where there are two second grooves 621 in the groove group 62 as an example, among the two second grooves 621 , the maximum groove depth of the second groove 621 away from the open end 631 is smaller than the maximum groove depth of the second groove 621 close to the open end 631 .

[0159] During the production process, the multiple second grooves 621 in the groove group 62 can be processed in a sequence in which the depth gradually increases from the non-open end 632 to the open end 631, so that the minimum residual thickness of the multiple second grooves 621 in the groove group 62 gradually decreases from the non-open end 632 to the open end 631.

[0160] In some embodiments, the minimum residual thickness of the first groove 61 is smaller than the minimum residual thickness of the second groove 621 .

[0161] The minimum residual thickness of the first groove 61 is the minimum thickness of the remaining portion of the pressure relief component 6 after the first groove 61 is provided. The remaining portion of the first groove 61 may be the bottom wall of the first groove 61. The thickness of the remaining portion of the first groove 61 may be uniform or uneven. If the thickness of the remaining portion of the first groove 61 is uneven, the thickness of the thinnest portion of the remaining portion of the first groove 61 is the minimum residual thickness of the first groove 61.

[0162] It can be understood that the minimum residual thickness of the first groove 61 is smaller than the minimum residual thickness of all the second grooves 621 in the groove group 62 .

[0163] In the slot group 62, the minimum residual thicknesses of the multiple second slots 621 can be equal or unequal. In an embodiment where the minimum residual thicknesses of the multiple second slots 621 in the slot group 62 gradually decrease from the non-open end 632 toward the open end 631, the minimum residual thickness of the first slot 61 is less than the minimum residual thickness of the second slot 621 in the slot group 62 closest to the open end 631. As shown in FIG7 , the minimum residual thickness of the first slot 61 is D1, and the minimum residual thickness of the second slot 621 in the slot group 62 closest to the open end 631 (the second slot 621 with the smallest minimum residual thickness in the slot group 62) is D2, where D1 is less than D2.

[0164] In this embodiment, the minimum residual thickness of the first groove 61 is less than the minimum residual thickness of the second groove 621, so that the strength of the residual part of the first groove 61 is less than the strength of the residual part of the second groove 621, so that the pressure relief component 6 can preferentially crack along the first groove 61 to achieve rapid opening of the predetermined pressure relief area 63.

[0165] In some embodiments, the minimum residual thickness of the first groove 61 is D1, 0.1 mm≤D1≤0.5 mm.

[0166] D1 can take any point value among 0.1mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, 0.32mm, 0.35mm, 0.38mm, 0.4mm, 0.42mm, 0.45mm, 0.48mm, 0.5mm, etc., or a range value between any two of them.

[0167] D1≥0.1mm, so that the remaining part of the first groove 61 has sufficient strength, reducing the risk of the pressure relief component 6 cracking along the first groove 61 in advance during the long-term circulation of the battery cell 10, thereby improving the service life of the battery cell 10; D1≤0.5mm, so that the pressure relief component 6 can be cracked along the first groove 61 more promptly when the battery cell 10 thermally runs away, reducing the risk of fire or explosion of the battery cell 10.

[0168] In some embodiments, the maximum groove depth of the first groove 61 is greater than the maximum groove depth of the second groove 621 .

[0169] The maximum distance between the opening of the first groove 61 and the bottom surface of the first groove 61 along the thickness direction X of the first wall portion is the maximum groove depth of the first groove 61. As an example, the sum of the maximum groove depth of the first groove 61 and the minimum residual thickness of the first groove 61 is equal to the thickness of the first wall portion 13.

[0170] It can be understood that the maximum groove depth of the first groove 61 is greater than the maximum groove depth of all the second grooves 621 in the groove group 62 .

[0171] In the groove group 62, the maximum groove depths of the multiple second grooves 621 can be equal or unequal. In an embodiment where the maximum groove depths of the multiple second grooves 621 in the groove group 62 gradually increase from the non-open end 632 toward the open end 631, the maximum groove depth of the first groove 61 is greater than the maximum groove depth of the second groove 621 in the groove group 62 closest to the open end 631. As shown in Figure 7, the maximum groove depth of the first groove 61 is H1, and the maximum groove depth of the second groove 621 in the groove group 62 closest to the open end 631 (the second groove 621 with the greatest maximum groove depth in the groove group 62) is H2, where H2 < H1. As an example, the thickness of the first wall portion 13 is D, and D = H1 + D1 = H2 + D2.

[0172] During the production process, the depth of the first groove 61 can be processed deeper than that of the second groove 621 , which reduces the difficulty of achieving a minimum residual thickness of the first groove 61 smaller than the minimum residual thickness of the second groove 621 .

[0173] In some embodiments, please continue to refer to Figure 5. The first groove 61 has two ends, and the line connecting the two ends is a first line W. The first groove 61 is connected to the first line W and together encloses a predetermined pressure relief area 63. The predetermined pressure relief area 63 has an open end 631 and a non-open end 632. The first line W is located at the non-open end 632. The open end 631 and the non-open end 632 are arranged opposite each other along the width direction of the second groove 621. The projection of at least one second groove 621 in the groove group 62 along the thickness direction X of the first wall portion is located in the predetermined pressure relief area 63, and is located between the open end 631 and the non-open end 632 along the width direction of the second groove 621. The width direction of the second groove 621 is perpendicular to the thickness direction X of the first wall portion.

[0174] The first connecting line W is a line connecting the two ends of the first groove 61, and the first connecting line W is a straight line. A first groove 61 can be connected to a first connecting line W and together enclose a predetermined pressure relief area 63, or a first groove 61 can be connected to multiple second connecting lines and together enclose multiple predetermined pressure relief areas 63. As an example, in the embodiment shown in FIG5 , the first groove 61 is an H-shaped groove. Along the width direction of the second groove 621, both sides of the first groove 61 have two ends. The first groove 61 is connected to two first connecting lines W and together encloses two predetermined pressure relief areas 63.

[0175] The first groove 61 may include only one groove segment 611 or multiple groove segments 611. If the first groove 61 includes only one groove segment 611, the groove segment 611 and the first connecting line W may be connected end to end in sequence to enclose a predetermined pressure relief area 63. If the first groove 61 includes multiple groove segments 611, the multiple groove segments 611 and the first connecting line W may be connected end to end to enclose a predetermined pressure relief area 63.

[0176] In the groove group 62, the projections of a portion of the second grooves 621 along the thickness direction X of the first wall portion may be located within the predetermined pressure relief area 63, and the projections of another portion of the second grooves 621 along the thickness direction X of the first wall portion may be located outside the predetermined pressure relief area 63; or the projections of all the second grooves 621 along the thickness direction X of the first wall portion may be located within the predetermined pressure relief area 63.

[0177] In this embodiment, the projection of at least one second groove 621 in the groove group 62 along the thickness direction X of the first wall is located in the predetermined pressure relief area 63, and along the width direction of the second groove 621 is located between the open end 631 and the non-open end 632. This causes at least two regions of the predetermined pressure relief area 63 to flip, thereby reducing the area swept by the predetermined pressure relief area 63 during flipping, reducing the flipping space required for the predetermined pressure relief area 63, and reducing the risk of interference between the predetermined pressure relief area 63 and external components, thereby improving the reliability of the battery cell 10. The external component can be a wall of the battery case 20 opposite the first wall 13 in the battery 100, or a thermal management component disposed opposite the first wall 13 in the battery 100. The thermal management component can be a water cooling plate or a heating element.

[0178] Please refer to Figures 8 and 9. Figure 8 is a cross-sectional view of the housing 1 shown in Figure 6 (with a portion of the predetermined pressure relief area 63 open); Figure 9 is a cross-sectional view of the housing 1 shown in Figure 6 (with the predetermined pressure relief area 63 fully open). Taking the example of two second grooves 621 in the groove group 62, when the battery cell 10 releases pressure, a portion of the predetermined pressure relief area 63 first rotates around the remaining portion of the second groove 621 near the open end 631. The predetermined pressure relief area 63 then rotates around the remaining portion of the second groove 621 farther from the open end 631. This effectively reduces the area swept by the predetermined pressure relief area 63 during rotation, thereby reducing the required rotation space for the predetermined pressure relief area 63.

[0179] 5 , in some embodiments, a projection of at least one second groove 621 in the groove group 62 along the thickness direction X of the first wall portion does not overlap with a projection of the predetermined pressure relief area 63 along the thickness direction X of the first wall portion.

[0180] In the groove group 62, the projection of one second groove 621 along the thickness direction X of the first wall portion may not overlap with the projection of the predetermined pressure relief zone 63 along the thickness direction X of the first wall portion, that is, the projection of one second groove 621 in the groove group 62 along the thickness direction X of the first wall portion is located outside the predetermined pressure relief zone 63; or the projection of multiple second grooves 621 along the thickness direction X of the first wall portion may not overlap with the projection of the predetermined pressure relief zone 63 along the thickness direction X of the first wall portion, that is, the projection of multiple second grooves 621 in the groove group 62 along the thickness direction X of the first wall portion is located outside the predetermined pressure relief zone 63.

[0181] As an example, in the embodiment shown in Figure 5, there are two second grooves 621 in the groove group 62, and the projection of one of the two second grooves 621 along the thickness direction X of the first wall portion is located within the predetermined pressure relief area 63, and the projection of the other second grooves along the thickness direction X of the first wall portion is located outside the predetermined pressure relief area 63.

[0182] In this embodiment, the projection of at least one second groove 621 in the groove group 62 along the thickness direction X of the first wall does not overlap with the projection of the predetermined pressure relief zone 63 along the thickness direction X of the first wall. This allows the at least one second groove 621 to be located outside the predetermined pressure relief zone 63. This allows a larger area of ​​the predetermined pressure relief zone 63 to flip when the battery cell 10 experiences thermal runaway, thereby increasing the opening area of ​​the predetermined pressure relief zone 63. Furthermore, the second groove 621 located outside the predetermined pressure relief zone 63 absorbs excess material extruded during the molding of the first groove 61, thereby improving the flatness of the outer surface of the housing 1 in the width direction of the second groove 621 (the outer surface of the second wall 14 and the outer surface of the third wall 15). Furthermore, the second groove 621 located outside the predetermined pressure relief zone 63 can partially block the deformation energy of the housing 1 when the housing 1 is subjected to internal or external impact forces, thereby reducing the risk of premature opening of the predetermined pressure relief zone 63 due to expansion of the battery cell 10.

[0183] In some embodiments, at least one second groove 621 in the groove group 62 is a first guide groove 621a, and the projection of the first guide groove 621a along the thickness direction X of the first wall portion does not overlap with the projection of the predetermined pressure relief area 63 along the thickness direction X of the first wall portion. The first guide groove 621a and the first groove 61 are spaced apart along the width direction of the first guide groove 621a, and the two ends of the projection of the first guide groove 621a along the thickness direction X of the first wall portion extend out of the two ends of the first groove 61 along the extension direction.

[0184] The first guide groove 621a is a second groove 621 in the groove group 62 that does not overlap with the projection of the predetermined pressure relief area 63 along the thickness direction X of the first wall. The width of the first guide groove 621a is the same as the width of the second groove 621. The first guide groove 621a is spaced apart from the first groove 61 along the width direction of the first guide groove 621a. That is, the projection of the first guide groove 621a along the thickness direction X of the first wall is spaced apart from the projection of the first groove 61 along the thickness direction X of the first wall by a certain distance in the width direction of the first guide groove 621a. In this embodiment, the first guide groove 621a and the first groove 61 can be located on the same side of the pressure relief component 6 along the thickness direction X of the first wall, or on opposite sides of the pressure relief component 6 along the thickness direction X of the first wall.

[0185] As an example, the length of the first guide groove 621 a is greater than the length of a line (first line W) connecting both ends of the first groove 61 .

[0186] In this embodiment, the first guide groove 621a is spaced apart from the first groove 61 along the width of the first guide groove 621a. The ends of the first guide groove 621a extend beyond the ends of the first groove 61, making the first guide groove 621a longer and enhancing its ability to assist in the flipping of the predetermined pressure relief zone 63. This structure also enhances the separation between the surface of the housing 1 in the width direction of the first guide groove 621a and the first groove 61, improves the absorption of excess material extruded during the molding of the first groove 61, further improves the flatness of the outer surface of the housing 1 in the width direction of the first guide groove 621a, and enhances the effectiveness of the first guide groove 621a in blocking deformation energy of the housing 1 when subjected to internal or external impact forces, further reducing the risk of premature opening of the predetermined pressure relief zone 63 due to expansion of the battery cell 10.

[0187] In some embodiments, referring to FIG10 , which is a partial view of the housing 1 provided in some embodiments of the present application, all second grooves 621 in the groove group 62 are located in the predetermined pressure relief area 63 as projected along the thickness direction X of the first wall portion, and are located between the open end 631 and the non-open end 632 along the width direction of the second groove 621.

[0188] It can be understood that if there are two second grooves 621 in the groove group 62, the projections of the two second grooves 621 along the thickness direction X of the first wall portion are located in the predetermined pressure relief area 63; if there are three second grooves 621 in the groove group 62, the projections of the three second grooves 621 along the thickness direction X of the first wall portion are located in the predetermined pressure relief area 63; if there are four second grooves 621 in the groove group 62, the projections of the four second grooves 621 along the thickness direction X of the first wall portion are located in the predetermined pressure relief area 63; if there are five second grooves 621 in the groove group 62, the projections of the five second grooves 621 along the thickness direction X of the first wall portion are located in the predetermined pressure relief area 63.

[0189] In this embodiment, the projections of all the second grooves 621 in the groove group 62 along the thickness direction X of the first wall portion are located in the predetermined pressure relief area 63, and are located at the open end 631 and the non-open end 632 along the width direction of the second grooves 621, so that more areas of the predetermined pressure relief area 63 are flipped, further reducing the area swept by the predetermined pressure relief area 63 when flipping, and reducing the flipping space required for the predetermined pressure relief area 63.

[0190] In some embodiments, referring to FIG. 5 and FIG. 10 , along the thickness direction X of the first wall portion, the projection of the second groove 621 does not overlap with the projection of the first groove 61 .

[0191] It can be understood that the projection of the second groove 621 along the thickness direction X of the first wall portion and the projection of the first groove 61 along the thickness direction X of the first wall portion do not have an overlapping area.

[0192] In this embodiment, the projection of the second groove 621 along the thickness direction X of the first wall portion does not overlap with the projection of the first groove 61 along the thickness direction X of the first wall portion, so that the projection of the second groove 621 along the thickness direction X of the first wall portion is not connected to the projection of the first groove 61 along the thickness direction X of the first wall portion, thereby reducing the mutual influence between the first groove 61 and the second groove 621 during the processing process and reducing the risk of the first groove 61 and the second groove 621 being connected to each other during the processing.

[0193] In some embodiments, the first groove 61 defines a plurality of predetermined pressure relief areas 63 .

[0194] The first groove 61 may define two, three, four or more predetermined pressure relief areas 63. As an example, in the embodiments shown in FIG5 and FIG10, the first groove 61 defines two predetermined pressure relief areas 63.

[0195] When the battery cell 10 experiences thermal runaway, the plurality of predetermined pressure relief areas 63 can all be opened. When the total pressure relief area of ​​the pressure relief component 6 is constant, the opening rate of the predetermined pressure relief areas 63 can be increased, thereby achieving faster pressure relief.

[0196] In some embodiments, referring to FIG. 5 and FIG. 10 , the first wall portion 13 is a rectangular wall portion, and the plurality of second grooves 621 in the groove group 62 are spaced apart along the width direction Z of the first wall portion.

[0197] As an example, the width direction of the second groove 621 is parallel to the width direction Z of the first wall portion.

[0198] The housing 1 can be in the shape of a rectangular parallelepiped, and the first wall 13 can be any rectangular wall in the housing 1. The first wall 13 is a rectangular wall, that is, when viewed along the thickness direction X of the first wall, the first wall 13 is generally rectangular. The length of the first wall 13 is greater than the width of the first wall 13.

[0199] When the first wall portion 13 is deformed due to the expansion of the battery cell 10, the deformation of the first wall portion 13 in the width direction is smaller than that in the length direction Y of the first wall portion. The multiple second grooves 621 in the groove group 62 are arranged at intervals along the width direction Z of the first wall portion. This can reduce the impact of the deformation of the first wall portion 13 on the second grooves 621, and reduce the risk of fatigue cracking of the pressure relief component 6 along the second grooves 621 during the normal cycle life of the battery cell 10.

[0200] In some embodiments, please continue to refer to Figure 6. Along the thickness direction X of the first wall portion, the pressure relief component 6 has a first surface 64 and a second surface 65 relative to each other, the first groove 61 is recessed from the first surface 64 toward the direction close to the second surface 65, and the second groove 621 is recessed from the second surface 65 toward the direction close to the first surface 64.

[0201] The first surface 64 and the second surface 65 are two opposing surfaces of the pressure relief component 6 along the thickness direction X of the first wall portion. The first groove 61 is recessed from the first surface 64 toward the second surface 65, that is, the first groove 61 is provided on the first surface 64; the second groove 621 is recessed from the second surface 65 toward the first surface 64, that is, the second groove 621 is provided on the second surface 65. One of the first surface 64 and the second surface 65 can be the outer surface of the pressure relief component 6, and the other can be the inner surface of the pressure relief component 6. The outer surface of the pressure relief component 6 faces the exterior of the battery cell 10, and the inner surface of the pressure relief component 6 faces the interior of the battery cell 10. The first surface 64 and the second surface 65 can be planes, and the first surface 64 and the second surface 65 can be parallel or arranged at a non-zero angle.

[0202] As an example, in the embodiment shown in FIG6 , the first surface 64 is parallel to the second surface 65. The minimum distance between the bottom surface of the first groove 61 and the second surface 65 along the thickness direction X of the first wall portion is equal to the minimum residual thickness of the first groove 61, and the minimum distance between the bottom surface of the second groove 621 and the first surface 64 along the thickness direction X of the first wall portion is equal to the minimum residual thickness of the second groove 621. The maximum groove depth of the first groove 61 is equal to the maximum distance between the first surface 64 and the bottom surface of the first groove 61 along the thickness direction X of the first wall portion, and the maximum groove depth of the second groove 621 is equal to the maximum distance between the second surface 65 and the bottom surface of the second groove 621 along the thickness direction X of the first wall portion.

[0203] In this embodiment, the first groove 61 and the second groove 621 are respectively located on both sides of the pressure relief component 6 along the thickness direction X of the first wall portion, so that the first groove 61 and the second groove 621 can be processed on both sides of the pressure relief component 6, which is beneficial to reducing the mutual influence between the first groove 61 and the second groove 621 during the processing.

[0204] In some embodiments, referring to FIG11 , which is a cross-sectional view of a housing 1 provided in some embodiments of the present application, the pressure relief component 6 has a first surface 64 and a second surface 65 facing each other along the thickness direction X of the first wall portion, and the first groove 61 and the second groove 621 are both recessed from the first surface 64 toward the second surface 65.

[0205] The first groove 61 and the second groove 621 are both recessed from the first surface 64 toward the second surface 65, that is, the first groove 61 and the second groove 621 are both provided on the first surface 64. One of the first surface 64 and the second surface 65 is the inner surface of the pressure relief component 6, and the other is the outer surface of the pressure relief component 6.

[0206] In this embodiment, the first groove 61 and the second groove 621 are both recessed from the first surface 64 toward the second surface 65. The first groove 61 and the second groove 621 are arranged on the same side of the pressure relief component 6 in the thickness direction, which makes it easier to process the first groove 61 and the second groove 621 on the pressure relief component 6. The first groove 61 and the second groove 621 can be processed without flipping the pressure relief component 6, which is beneficial to optimizing the production rhythm of the battery cell 10.

[0207] In some embodiments, referring to FIG. 6 and FIG. 11 , the first surface 64 is the surface of the pressure relief component 6 facing the outside of the battery cell 10 , and the second surface 65 is the surface of the pressure relief component 6 facing the inside of the battery cell 10 .

[0208] The first surface 64 is the outer surface of the pressure relief component 6 , and the second surface 65 is the inner surface of the pressure relief component 6 .

[0209] Referring to Figures 6 and 11 , when the first groove 61 is provided on the first surface 64 , it is positioned outside the pressure relief component 6 , facilitating the molding of the first groove 61 on the exterior of the housing 1 , thereby reducing the difficulty in molding the first groove 61 and improving the production efficiency of the battery cell 10 . Referring to Figure 11 , when the second groove 621 is provided on the first surface 64 , it is positioned outside the pressure relief component 6 , facilitating the molding of the second groove 621 on the exterior of the housing 1 , thereby reducing the difficulty in molding the second groove 621 . Referring to Figures 6 and 11 , when the second groove 621 is provided on the second surface 65 , it is positioned inside the pressure relief component 6 . This prevents the two side faces of the second groove 621 along the width direction from abutting against each other during the outward flipping and opening of the predetermined pressure relief area 63 , thereby increasing the opening area of ​​the predetermined pressure relief area 63 . Furthermore, the second groove 621 is not exposed to the exterior of the battery cell 10 , reducing the risk of oxidation and corrosion of the pressure relief component 6 in the region of the second groove 621 .

[0210] In some embodiments, referring to Figures 12-14, Figure 12 is a partial view of a housing 1 provided in other embodiments of the present application; Figure 13 is a CC cross-sectional view of the housing 1 shown in Figure 12; and Figure 14 is a partial enlarged view of point D in Figure 13. The first groove 61 includes multiple levels of grooves arranged sequentially along the direction from the first surface 64 to the second surface 65. Along the thickness direction X of the first wall portion, in two adjacent levels of grooves, the first level groove farther from the first surface 64 is arranged at the bottom surface of the first level groove closer to the first surface 64.

[0211] The first groove 61 is a stepped groove, which can be a two-stage groove, a three-stage groove, a four-stage groove, a five-stage groove, or the like. The groove width of each stage gradually decreases along the direction from the first surface 64 to the second surface 65. It is understood that in the multi-stage groove of the first groove 61, the first stage groove with the largest groove width is located on the first surface 64. For example, in the case of a two-stage first groove 61, the two stages are the first stage groove and the second stage groove. During machining, the first stage groove with a larger width can be machined first on the first surface 64, and then the second stage groove with a smaller width can be machined on the bottom surface of the first stage groove.

[0212] In the embodiment where the first groove 61 includes multiple groove segments 611, it is understood that each groove segment 611 is a multi-stage groove, that is, each groove segment 611 is a stepped groove. In the multi-stage groove of the first groove 61, the groove bottom surface of the primary groove farthest from the first surface 64 is the groove bottom surface of the first groove 61, and the minimum residual thickness of the primary groove farthest from the first surface 64 is the minimum residual thickness of the first groove 61. As an example, the first surface 64 is parallel to the second surface 65, the minimum distance between the groove bottom surface of the primary groove farthest from the first surface 64 and the second surface 65 is equal to the minimum residual thickness of the first groove 61, and the maximum distance between the groove bottom surface of the primary groove farthest from the first surface 64 and the first surface 64 is equal to the maximum groove depth of the first groove 61.

[0213] By setting the first groove 61 as a multi-level groove arranged along the thickness direction X of the first wall portion, when forming the first groove 61, each level of groove can be processed one by one along the direction from the first surface 64 to the second surface 65, thereby reducing the forming depth of each level of groove, reducing the forming force exerted on the pressure relief component 6 when forming the first groove 61, and reducing the risk of the pressure relief component 6 being damaged when forming the first groove 61.

[0214] In some embodiments, please continue to refer to FIG. 12 to FIG. 14 , the first groove 61 includes a plurality of groove segments 611 , the plurality of groove segments 611 are connected, and the plurality of groove segments 611 together define at least one predetermined pressure relief area 63 .

[0215] The slot segment 611 can extend along a straight trajectory or a non-straight trajectory. The non-straight trajectory can be an arc trajectory, a parabolic trajectory, etc. Multiple slot segments 611 can jointly define a predetermined pressure relief zone 63, for example, multiple slot segments 611 form a V-shaped groove or a U-shaped groove, etc.; multiple slot segments 611 can jointly define multiple predetermined pressure relief zones 63, for example, multiple slot segments 611 form an H-shaped groove, an X-shaped groove, a Y-shaped groove, etc., wherein the H-shaped groove defines two predetermined pressure relief zones 63, the X-shaped groove defines four predetermined pressure relief zones 63, and the Y-shaped groove defines three predetermined pressure relief zones 63.

[0216] In the first groove 61 , the minimum residual thicknesses of the multiple groove segments 611 may be equal, or the minimum residual thicknesses of at least two groove segments 611 may be different. If the minimum residual thicknesses of at least two groove segments 611 are different, the minimum residual thickness of the groove segment 611 with the smallest minimum residual thickness among the multiple groove segments 611 is the minimum residual thickness of the first groove 61 .

[0217] In this embodiment, a plurality of groove sections 611 can define a larger predetermined pressure relief area 63 , which is beneficial for increasing the pressure relief area of ​​the battery cell 10 .

[0218] In some embodiments, please continue to refer to Figures 12-14, the multiple slot sections 611 include a first slot section 611a, a second slot section 611b and a third slot section 611c, the second slot section 611b and the third slot section 611c are arranged opposite to each other, and the multiple second grooves 621 in the slot group 62 are located on the same side of the first slot section 611a in the width direction, the first slot section 611a connects the second slot section 611b and the third slot section 611c, and the first slot section 611a, the second slot section 611b and the third slot section 611c jointly define at least one predetermined pressure relief area 63.

[0219] The first slot segment 611a, the second slot segment 611b, and the third slot segment 611c are the three slot segments 611 in the first groove 61. The first slot segment 611a, the second slot segment 611b, and the third slot segment 611c can be linear slots extending along a linear trajectory, or non-linear slots extending along a non-linear trajectory. If the first slot segment 611a, the second slot segment 611b, and the third slot segment 611c all extend along a linear trajectory, the first slot segment 611a and the second slot segment 611b can be arranged at an acute angle, a right angle, or an obtuse angle. The first slot segment 611a and the third slot segment 611c can be arranged at an acute angle, a right angle, or an obtuse angle. The second slot segment 611b and the third slot segment 611c can be arranged parallel to each other, or the extension line of the second slot segment 611b and the extension line of the third slot segment 611c can intersect. The first slot segment 611a and the second groove 621 can be arranged parallel to each other.

[0220] The first slot segment 611a connects the second slot segment 611b and the third slot segment 611c. The first slot segment 611a may be connected to the second slot segment 611b and the third slot segment 611c at both ends, or at least one of the second slot segment 611b and the third slot segment 611c may be connected to a position offset from the end of the first slot segment 611a, such that at least one of the second slot segment 611b and the third slot segment 611c is located between the two ends of the first slot segment 611a. The second slot segment 611b may be connected to the first slot segment 611a at one end of the second slot segment 611b or between the two ends of the second slot segment 611b. The third slot segment 611c may be connected to the first slot segment 611a at one end of the third slot segment 611c or between the two ends of the third slot segment 611c. The first groove segment 611a, the second groove segment 611b, and the third groove segment 611c can collectively define one predetermined pressure relief area 63, or can collectively define multiple predetermined pressure relief areas 63. The first groove segment 611a, the second groove segment 611b, and the third groove segment 611c can form a U-shaped groove, an H-shaped groove, or the like. If the first groove segment 611a, the second groove segment 611b, and the third groove segment 611c form a U-shaped groove, the first groove 61 of this structure defines one predetermined pressure relief area 63. If the first groove segment 611a, the second groove segment 611b, and the third groove segment 611c form an H-shaped groove, the first groove 61 of this structure defines two predetermined pressure relief areas 63.

[0221] It should be noted that, in the embodiment where the first groove 61 is a multi-stage groove structure, the first groove section 611 a , the second groove section 611 b and the second groove section 611 b are all multi-stage groove structures.

[0222] In this embodiment, the first groove section 611a, the second groove section 611b and the third groove section 611c are connected and jointly define at least one predetermined pressure relief area 63. The first groove 61 with such a structure makes the intersection position of the first groove section 611a and the second groove section 611b and the connection position of the first groove section 611a and the third groove section 611c weaker, and is more likely to crack and open the predetermined pressure relief area 63 for pressure relief, and can further increase the opening area of ​​the predetermined pressure relief area 63, thereby increasing the pressure relief area of ​​the battery cell 10 and improving the pressure relief rate of the battery cell 10.

[0223] In some embodiments, the connection position between the second slot segment 611b and the first slot segment 611a deviates from the two ends of the second slot segment 611b, and the connection position between the third slot segment 611c and the first slot segment 611a deviates from the two ends of the third slot segment 611c, so that a predetermined pressure relief area 63 is formed on both sides of the first slot segment 611a.

[0224] The connection between the second slot segment 611b and the first slot segment 611a is offset from the ends of the second slot segment 611b. That is, the connection between the second slot segment 611b and the first slot segment 611a is not located at either end of the second slot segment 611b. Along the extension direction of the second slot segment 611b, the connection between the second slot segment 611b and the first slot segment 611a is located between the ends of the second slot segment 611b. The connection between the second slot segment 611b and the first slot segment 611a can be located at the midpoint of the second slot segment 611b or offset from the midpoint of the second slot segment 611b.

[0225] The connection between the third slot segment 611c and the first slot segment 611a is offset from the ends of the third slot segment 611c. That is, the connection between the third slot segment 611c and the first slot segment 611a is not located at either end of the third slot segment 611c. Along the extension direction of the third slot segment 611c, the connection between the third slot segment 611c and the first slot segment 611a is located between the ends of the third slot segment 611c. The connection between the third slot segment 611c and the first slot segment 611a can be located at the midpoint of the third slot segment 611c or offset from the midpoint of the third slot segment 611c.

[0226] As an example, in the embodiments shown in Figures 12-14, the connection point between the second slot segment 611b and the first slot segment 611a is located at the midpoint of the second slot segment 611b, and the connection point between the third slot segment 611c and the first slot segment 611a is located at the midpoint of the third slot segment 611c. The first slot segment 611a, the second slot segment 611b, and the third slot segment 611c form an H-shaped slot. There are two predetermined pressure relief areas 63. A portion of the second slot segment 611b, a portion of the third slot segment 611c, the first slot segment 611a, and a first connecting line W together enclose one predetermined pressure relief area 63. Another portion of the second slot segment 611b, another portion of the third slot segment 611c, the first slot segment 611a, and another first connecting line W together enclose another predetermined pressure relief area 63. The first groove 61 is provided on the first surface 64, and the second groove 621 is provided on the second surface 65.

[0227] In this embodiment, the connection position between the second slot segment 611b and the first slot segment 611a is offset from the ends of the second slot segment 611b. During the pressure relief process, after the pressure relief component 6 cracks at the connection position between the second slot segment 611b and the first slot segment 611a, the crack can spread along the second slot segment 611b to the ends of the second slot segment 611b, thereby shortening the time it takes for the pressure relief component 6 to crack along the second slot segment 611b. The connection position between the third slot segment 611c and the first slot segment 611a is offset from the ends of the third slot segment 611c. During the pressure relief process, after the pressure relief component 6 cracks at the connection position between the third slot segment 611c and the first slot segment 611a, the crack can spread along the third slot segment 611c to the ends of the third slot segment 611c, thereby shortening the time it takes for the pressure relief component 6 to crack along the third slot segment 611c. In such a structure, the first groove section 611a of the first groove 61 is located between the two predetermined pressure relief areas 63. After the pressure relief component 6 is split along the first groove section 611a, the two predetermined pressure relief areas 63 can be opened in a split manner to relieve pressure when the battery cell 10 is depressurized, so that the two predetermined pressure relief areas 63 can be opened quickly, which is beneficial to improving the pressure relief rate of the battery cell 10.

[0228] In some embodiments, referring to Figures 15 and 16, Figure 15 is a partial view of a housing 1 provided in some further embodiments of the present application; Figure 16 is a cross-sectional view taken along line FF of the housing 1 shown in Figure 15. The plurality of slot segments 611 include a first slot segment 611a and a second slot segment 611b. The first slot segment 611a is connected to the second slot segment 611b, and the first slot segment 611a and the second slot segment 611b together define at least one predetermined pressure relief area 63.

[0229] The first groove section 611a and the second groove section 611b are two groove sections 611 in the first groove 61. The first groove section 611a and the second groove section 611b can be linear grooves extending along a linear trajectory, or they can be non-linear grooves extending along a non-linear trajectory. If the first groove section 611a and the second groove section 611b both extend along a linear trajectory, the first groove section 611a and the second groove section 611b can be arranged at an acute angle, a right angle, or an obtuse angle. The first groove section 611a and the second groove section 611b can be connected end-to-end to form a V-shaped groove, an L-shaped groove, etc. The first groove 61 of this structure can enclose a predetermined pressure relief area 63 with a first connecting line W. The first groove section 611a and the second groove section 611b can also be arranged crosswise to form an X-shaped groove. The first groove 61 of this structure can enclose four predetermined pressure relief areas 63 with four first connecting lines W.

[0230] As an example, in the embodiments shown in FIG. 15 and FIG. 16 , the first groove segment 611 a is connected to the second groove segment 611 b to form a V-shaped structure, the first groove 61 is provided on the first surface 64 , and the second groove 621 is provided on the second surface 65 .

[0231] In the embodiment in which the first groove 61 is a multi-stage groove structure, both the first groove section 611 a and the second groove section 611 b have a multi-stage groove structure.

[0232] In this embodiment, the first groove section 611a and the second groove section 611b are connected and jointly define at least one predetermined pressure relief area 63. The first groove 61 of this structure has a simple structure. The stress concentration coefficient at the position where the first groove section 611a and the second groove section 611b are connected is larger, and the pressure relief component 6 is weaker and more likely to crack. When the battery cell 10 thermally runs away, after the pressure relief component 6 cracks at the position where the first groove section 611a and the second groove section 611b are connected, it can quickly crack from the first groove section 611a and the second groove section 611b, so that the predetermined pressure relief area 63 opens more quickly and the pressure is relieved in time.

[0233] In some embodiments, the slot segments 611 extend along a straight trajectory.

[0234] It is understood that in the embodiment where the first groove 61 includes the first groove segment 611a and the second groove segment 611b, the first groove segment 611a and the second groove segment 611b both extend along a straight line. In the embodiment where the first groove 61 includes the first groove segment 611a, the second groove segment 611b, and the third groove segment 611c, the first groove segment 611a, the second groove segment 611b, and the third groove segment 611c both extend along a straight line.

[0235] In this embodiment, the slot segment 611 extends along a straight track. The slot segment 611 is a straight slot, which can reduce the difficulty of forming the slot segment 611 .

[0236] In some embodiments, the slot segment 611 extends along an arcuate trajectory.

[0237] It is understood that in the embodiment where the first groove 61 includes the first groove segment 611a and the second groove segment 611b, the first groove segment 611a and the second groove segment 611b both extend along an arcuate trajectory. In the embodiment where the first groove 61 includes the first groove segment 611a, the second groove segment 611b, and the third groove segment 611c, the first groove segment 611a, the second groove segment 611b, and the third groove segment 611c both extend along an arcuate trajectory.

[0238] In this embodiment, the groove section 611 extends along an arc trajectory and is an arc-shaped groove. The pressure relief component 6 is more likely to break along the groove section 611 when the battery cell 10 releases pressure, thereby achieving faster opening of the predetermined pressure relief area 63.

[0239] In some embodiments, please refer to Figures 17 and 18, Figure 17 is a partial view of the housing 1 provided in some embodiments of the present application; Figure 18 is a GG cross-sectional view of the housing 1 shown in Figure 17. The first groove 61 extends along an arc track.

[0240] The central angle of the first groove 61 may be less than 15°, 30°, 45°, 60°, 90°, 120°, 150°, 180°, 210°, 240°, 270°, 300°, 330°, etc.

[0241] As an example, in the embodiments shown in Figures 17 and 18, the first groove 61 is arranged on the first surface 64, the second groove 621 is arranged on the second surface 65, and the line connecting the two ends of the first groove 61 is the first line W. The first groove 61 and the first line W together enclose a predetermined pressure relief area 63.

[0242] In this embodiment, the first groove 61 extends along an arc-shaped track. The first groove 61 of this structure only includes one groove segment 611 , which simplifies the structure of the first groove 61 .

[0243] In some embodiments, the second groove 621 extends along a straight line. The second groove 621 has a simple structure and is easy to process and form.

[0244] In some embodiments, please refer to Figure 19, which is an exploded view of the housing 1 (one end of the housing 11 is open, and the end cover 12 is the first wall portion 13) provided in some embodiments of the present application. The pressure relief component 6 is integrally formed with the first wall portion 13.

[0245] The entire first wall portion 13 can serve as the pressure relief component 6, or a portion of the first wall portion 13 can serve as the pressure relief component 6, so that the pressure relief component 6 and the first wall portion 13 are integrally formed. The first groove 61 and the second groove 621 are both provided in the first wall portion 13. One of the first surface 64 and the second surface 65 of the pressure relief component 6 is the inner surface of the first wall portion 13, and the other is the outer surface of the first wall portion 13.

[0246] In this embodiment, the pressure relief component 6 is integrally formed with the first wall portion 13, so that the first groove 61 and the second groove 621 can be directly formed on the first wall portion 13, forming an integrated pressure relief structure with higher reliability, eliminating the installation process of the pressure relief component 6, and having better economy.

[0247] In some embodiments, the first groove 61 is stamped and formed on the first wall portion 13 ; and / or the second groove 621 is stamped and formed on the first wall portion 13 .

[0248] If the first groove 61 is a primary groove structure, when forming the first groove 61 on the first wall portion 13, the first wall portion 13 can be punched once to punch out the first groove 61 on the first wall portion 13; if the first groove 61 is a multi-stage groove structure, when forming the first groove 61 on the first wall portion 13, the first wall portion 13 can be punched multiple times, each time punching out a primary groove, and the first groove 61 is finally formed after multiple stampings.

[0249] In this embodiment, if the first groove 61 is stamped into the first wall portion 13, the first groove 61 is formed in a simple manner, which helps reduce the production cost of the battery cell 10. If the second groove 621 is stamped into the first wall portion 13, the second groove 621 is formed in a simple manner, which helps reduce the production cost of the battery cell 10.

[0250] In some embodiments, please refer to Figure 20, which is an exploded view of the housing 1 (one end of the housing 11 is open, and the end cover 12 is the first wall portion 13) provided in other embodiments of the present application. The pressure relief component 6 is provided separately from the first wall portion 13 and is mounted on the first wall portion 13.

[0251] The pressure relief component 6 and the housing 1 are separate components. The pressure relief component 6 is manufactured separately and then mounted on the first wall portion 13. The pressure relief component 6 can be mounted on the first wall portion 13 by welding, riveting, bonding, or other methods. As an example, the first wall portion 13 is provided with a pressure relief hole 131. The pressure relief component 6 covers the pressure relief hole 131 and is welded to the first wall portion 13.

[0252] In this embodiment, the pressure relief component 6 is a component independent of the housing 1 , and the pressure relief component 6 and the housing 1 can be produced and assembled separately, with low production difficulty and high efficiency.

[0253] In some embodiments, please continue to refer to Figures 19 and 20. The housing 1 includes a shell 11 and an end cover 12. An opening is formed at at least one end of the shell 11. The end cover 12 corresponds to the opening one by one. The end cover 12 closes the opening. At least one end cover 12 is a first wall portion 13.

[0254] The housing 11 may have only one opening, for example, only one end of the housing 11 may have an opening; the housing 11 may also have multiple openings, for example, openings at both opposite ends of the housing 11. The number of end caps 12 is the same as the number of openings of the housing 11. It is understood that if the housing 11 has only one opening, there is only one end cap 12, which serves as the first wall portion 13; if the housing 11 has two openings, there are two end caps 12, and one end cap 12 may serve as the first wall portion 13, or both end caps 12 may serve as the first wall portion 13.

[0255] In an embodiment where the housing 11 is open at one end, the positive electrode terminal 3 and the negative electrode terminal 3 may be disposed on the end cap 12, and the positive electrode tab 21 and the negative electrode tab 21 may be formed at the end of the electrode assembly 2 facing the end cap 12, so as to facilitate electrical connection with the positive electrode terminal 3 and the negative electrode terminal 3, respectively. In an embodiment where openings are formed at both opposing ends of the housing 11, the positive electrode terminal 3 may be disposed at one end cap 12, and the negative electrode terminal 3 may be disposed at the other end cap 12, and the positive electrode tab 21 and the negative electrode tab 21 may be formed at opposing ends of the electrode assembly 2, respectively, so as to facilitate electrical connection between the positive electrode terminal 3 and the negative electrode terminal 3, and between the positive electrode terminal 21 and the negative electrode terminal 3.

[0256] In the embodiment shown in FIG19 , an opening is formed at one end of the housing 11, and the end cap 12 serves as a first wall portion 13 (not shown in FIG19 ). The first wall portion 13 serves as a pressure relief component 6. In the embodiment shown in FIG20 , an opening is formed at one end of the housing 11, and the end cap 12 serves as a first wall portion 13. The pressure relief component 6 is mounted on the first wall portion 13.

[0257] In this embodiment, at least one end cover 12 is the first wall portion 13, so that at least one end cover 12 has a pressure relief function, and the difficulty of forming the first groove 61 and the second groove 621 on the end cover 12 or the difficulty of installing the pressure relief component 6 is lower.

[0258] In some embodiments, please refer to Figures 21 and 22. Figure 21 is an exploded view of a housing 1 (an opening is formed at one end of the housing 11, and the housing 11 includes a first wall portion 13) provided in some embodiments of the present application; Figure 22 is an exploded view of a housing 1 (an opening is formed at one end of the housing 11, and the housing 11 includes a first wall portion 13) provided in other embodiments of the present application. The housing 1 includes a housing 11 and an end cap 12. The housing 11 has an opening formed at least at one end. The end cap 12 corresponds to the opening one-to-one and closes the opening. At least one wall portion of the housing 11 is the first wall portion 13.

[0259] The shell 11 may have only one opening, for example, the shell 11 may have an opening formed at only one end; the shell 11 may also have multiple openings, for example, the shell 11 may have openings formed at both opposite ends. The number of end caps 12 is the same as the number of openings of the shell 11. It is understandable that if the shell 11 has only one opening, there will be one end cap 12; if the shell 11 has two openings, there will be two end caps 12. In the embodiment in which the shell 11 has an opening formed at one end, the positive electrode terminal 3 and the negative electrode terminal 3 may be provided on the end cap 12, and the positive tab 21 and the negative tab 21 may be formed at the end of the electrode assembly 2 facing the end cap 12, so as to be electrically connected to the positive electrode terminal 3 and the negative electrode terminal 3, respectively. In an embodiment where openings are formed at both opposing ends of the housing 11, the positive electrode terminal 3 can be provided on one end cap 12, and the negative electrode terminal 3 can be provided on the other end cap 12. The positive electrode tab 21 and the negative electrode tab 21 can be formed at opposing ends of the electrode assembly 2, respectively, to facilitate electrical connection between the positive electrode tab 21 and the positive electrode terminal 3, and between the negative electrode tab 21 and the negative electrode terminal 3. In the housing 11, one wall portion can be the first wall portion 13, or multiple wall portions can be the first wall portion 13.

[0260] In this embodiment, at least one wall portion of the housing 11 is a first wall portion 13, providing the housing 11 with a pressure relief function. When the battery cell 10 releases pressure, the exhaust from the interior of the battery cell 10 is less likely to affect external components outside the end cap 12, reducing the risk of damage to these components from the exhaust. These external components may include, for example, a busbar connected to the electrode terminal 3, a temperature sensor, or a voltage sensor. Exhaust includes, but is not limited to, electrolyte, dissolved or split positive and negative electrode sheets, separator fragments, high-temperature, high-pressure gases generated by the reaction, and flames.

[0261] In some embodiments, please continue to refer to Figures 21 and 22. Only one end of the shell 11 is formed with an opening, and the wall portion of the shell 11 opposite to the end cover 12 is the first wall portion 13.

[0262] As an example, the housing 11 is rectangular and further includes four side walls, which are arranged around the first wall portion 13. The four side walls and the first wall portion 13 together define the space inside the housing 11. In the embodiment shown in FIG21 , an opening is formed at one end of the housing 11. The wall portion of the housing 11 opposite the end cap 12 is the first wall portion 13, and the pressure relief component 6 is the first wall portion 13. In the embodiment shown in FIG22 , an opening is formed at one end of the housing 11. The wall portion of the housing 11 opposite the end cap 12 is the first wall portion 13, and the pressure relief component 6 is mounted on the first wall portion 13.

[0263] In this embodiment, the housing 11 is open at one end, simplifying the structure of the entire battery cell 10. The first wall 13 is the wall of the housing 11 opposite the end cap 12, and can achieve directional pressure relief from the bottom of the housing 11.

[0264] In some embodiments, please refer to Figure 23, which is an exploded view of a battery cell 10 provided in some other embodiments of the present application. Openings are formed at both opposite ends of the housing 11.

[0265] In the housing 11 , one wall portion or multiple walls may serve as the first wall portion 13 . The pressure relief component 6 may be integrally formed with the first wall portion 13 ; the pressure relief component 6 may also be provided separately from the first wall portion 13 , or the pressure relief component 6 may be installed on the first wall portion 13 .

[0266] As an example, the housing 11 is in the shape of a rectangular parallelepiped and includes four walls, which are connected end to end and together define the space inside the housing 11. Two opposing walls are large-area walls, and the other two are small-area walls. The outer surfaces of the large-area walls are larger than the outer surfaces of the small-area walls. One or two of the small-area walls in the housing 11 are first walls 13.

[0267] In this embodiment, the housing 11 has openings at both opposing ends. The electrode assembly 2 can be assembled into the housing 11 through either opening, which reduces the difficulty of assembling the battery cell 10 and improves the assembly quality of the battery cell 10. This structure of the housing 11 allows for a longer length (openings are formed at both ends of the housing 11 in the longitudinal direction), which helps increase the capacity of the battery cell 10.

[0268] In some embodiments, the pressure relief component 6 is made of steel.

[0269] The steel material can be carbon steel, alloy steel, stainless steel, etc.

[0270] It is understood that in the embodiment where the pressure relief component 6 and the first wall portion 13 are integrally formed, the material of the first wall portion 13 includes steel. If the first wall portion 13 is the end cap 12, the end cap 12 can be made of steel; if the first wall portion 13 is a wall portion in the housing 11, the housing 11 can be made of steel.

[0271] In this embodiment, the pressure relief component 6 made of steel has better strength. When the bursting pressure of the battery cell 10 is constant, the pressure relief component 6 can be made thinner to reduce the volume of the pressure relief component 6.

[0272] In some embodiments, the steel material is carbon steel or stainless steel.

[0273] In some embodiments, the pressure relief component 6 is made of aluminum alloy.

[0274] It is understood that in the embodiment where the pressure relief component 6 and the first wall portion 13 are integrally formed, the material of the first wall portion 13 includes an aluminum alloy. If the first wall portion 13 is the end cap 12, the end cap 12 can be made of an aluminum alloy; if the first wall portion 13 is a wall portion in the housing 11, the housing 11 can be made of an aluminum alloy.

[0275] Aluminum alloy has the characteristics of light weight and good ductility, and it is easier to process the first groove 61 and the second groove 621 on the pressure relief component 6.

[0276] In some embodiments, the aluminum alloy includes the following components in mass percentage: aluminum ≥ 99.6%, copper ≤ 0.05%, iron ≤ 0.35%, magnesium ≤ 0.03%, manganese ≤ 0.03%, silicon ≤ 0.25%, titanium ≤ 0.03%, vanadium ≤ 0.05%, zinc ≤ 0.05%, and other individual elements ≤ 0.03%.

[0277] This aluminum alloy belongs to the third series aluminum, has lower hardness and better forming ability, reduces the processing difficulty of the first groove 61 and the second groove 621, is conducive to improving the processing accuracy of the first groove 61 and the second groove 621, and improves the pressure relief consistency of the pressure relief component 6.

[0278] In some embodiments, the aluminum alloy includes the following components in mass percentage: aluminum ≥ 96.7%, 0.05% ≤ copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other individual element components ≤ 0.05%, and the total composition of other elements ≤ 0.15%.

[0279] This aluminum alloy belongs to the fifth series aluminum. The pressure relief component 6 made of this aluminum alloy has higher hardness, greater strength and good anti-destruction ability.

[0280] A battery 100 provided in an embodiment of the present application includes the battery cell 10 provided in any one of the above embodiments.

[0281] An embodiment of the present application provides an electrical device, including the battery cell 10 provided in any one of the above embodiments, and the battery cell 10 is used to provide electrical energy to the electrical device.

[0282] Referring to FIG3 , an embodiment of the present application further provides a battery cell 10, comprising a housing 1 and an electrode assembly 2. The electrode assembly 2 comprises a positive electrode tab 21 and a negative electrode tab 21, and the electrode assembly 2 is housed within the housing 1. The housing 1 is rectangular and comprises a shell 11 and an end cap 12. The shell 11 has an opening at one end, and the end cap 12 seals the opening. The end cap 12 is provided with a positive electrode terminal 3 and a negative electrode terminal 3. The positive electrode terminal 3 is electrically connected to the positive electrode tab 21 via a current collecting member 4, and the negative electrode terminal 3 is electrically connected to the negative electrode tab 21 via another current collecting member 4.

[0283] 12 to 14 , the wall portion of the housing 11 opposite to the end cover 12 is the pressure relief component 6. The pressure relief component 6 is a rectangular wall portion. The outer surface of the pressure relief component 6 is provided with a first groove 61. The first groove 61 is a two-stage groove. The first groove 61 includes a plurality of groove segments 611. The plurality of groove segments 611 form an H-shaped groove. The first groove 61 includes a first groove segment 611a, a second groove segment 611b, and a third groove segment 611c. The first groove segment 611a, the second groove segment 611b, and the third groove segment 611c all extend along a straight line. The second groove segment 611b and the third groove segment 611c are arranged in parallel. The first groove segment 611a connects the second groove segment 611b and the third groove segment 611c. The second groove segment 611b and the third groove segment 611c are both perpendicular to the first groove segment 611a. The connection between the groove section 611a and the second groove section 611b is located at the midpoint of the second groove section 611b, and the connection between the first groove section 611a and the third groove section 611c is located at the midpoint of the third groove section 611c. The first, second, and third groove sections 611a, 611b, and 611c collectively define two predetermined pressure relief areas 63. The pressure relief component 6 is configured to rupture along at least a portion of the first groove 61 when pressure is released from the battery cell 10. The inner surface of the pressure relief component 6 is provided with groove groups 62, each corresponding to a predetermined pressure relief area 63. Each groove group 62 includes two second grooves 621 spaced apart along the width of the groove 621. The second grooves 621 are configured to guide the flipping of at least a portion of the predetermined pressure relief area 63, thereby opening at least a portion of the predetermined pressure relief area 63. The minimum residual thickness of the first groove 61 is smaller than that of the second groove 621. The predetermined pressure relief zone 63 has an open end 631 and a non-open end 632, which are arranged opposite each other along the width of the second groove 621. The minimum residual thickness of the two second grooves 621 in the groove group 62 gradually decreases from the non-open end 632 to the open end 631. The projection of one second groove 621 in the groove group 62 along the thickness direction X of the first wall is located in the predetermined pressure relief zone 63, and is located between the open end 631 and the non-open end 632 along the width direction of the second groove 621. The projection of another second groove 621 in the groove group 62 along the thickness direction X of the first wall does not overlap with the projection of the predetermined pressure relief zone 63 along the thickness direction X of the first wall. The projection of the second groove 621 along the thickness direction X of the first wall extends beyond the two ends of the first groove 61 along the extension direction.

[0284] In such a battery cell 10, each slot group 62 includes a plurality of second slots 621, and the plurality of second slots 621 are spaced apart along the width direction of the second slot 621, and the minimum residual thickness of the plurality of second slots 621 in the slot group 62 gradually decreases in the direction from the non-open end 632 to the open end 631. The plurality of second slots 621 can all help the predetermined pressure relief area 63 to flip, making the flipping of the predetermined pressure relief area 63 easier, reducing the flipping difficulty of the predetermined pressure relief area 63, and reducing the area swept by the predetermined pressure relief area 63 when flipping, reducing the flipping space required for the predetermined pressure relief area 63, reducing the risk of interference between the predetermined pressure relief area 63 and external components, and improving the reliability of the battery cell 10.

[0285] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0286] The above embodiments are intended only to illustrate the technical solutions of this application and are not intended to limit this application. Those skilled in the art will appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application are intended to be within the scope of protection of this application.

Claims

1. A battery cell, comprising: A housing including a first wall portion; A pressure relief component disposed on the first wall portion, the pressure relief component including a first groove that defines at least one predetermined pressure relief area, and the pressure relief component is configured to be able to crack along at least a part of the first groove when the battery cell relieves pressure; Wherein, the pressure relief component further includes a groove group, the groove group corresponds to the predetermined pressure relief area one by one, each groove group includes a plurality of second grooves, and the plurality of second grooves are spaced apart along the width direction of the second groove, and the second groove is configured to guide at least a part of the predetermined pressure relief area to flip to open at least a part of the predetermined pressure relief area.

2. The battery cell according to claim 1, wherein, The predetermined pressure relief area has an opening end and a non-opening end, the opening end and the non-opening end are oppositely arranged along the width direction of the second groove, and the minimum remaining thickness of the plurality of second grooves in the groove group gradually decreases along the direction from the non-opening end to the opening end.

3. The battery cell according to claim 2, wherein, The maximum groove depth of the plurality of second grooves in the groove group gradually increases along the direction from the non-opening end to the opening end.

4. The battery cell according to any one of claims 1-3, wherein, The minimum remaining thickness of the first groove is less than the minimum remaining thickness of the second groove.

5. The battery cell according to claim 4, wherein, The minimum remaining thickness of the first groove is D1, and 0.1mm ≤ D1 ≤ 0.5mm.

6. The battery cell according to claim 4 or 5, wherein, The maximum groove depth of the first groove is greater than the maximum groove depth of the second groove.

7. The battery cell according to any one of claims 1-6, wherein, The first groove has two ends, and the connection line of the two ends is a first connection line. The first groove is connected to the first connection line and together encloses the predetermined pressure relief area; The predetermined pressure relief area has an opening end and a non-opening end, the first connection line is located at the non-opening end, the opening end and the non-opening end are oppositely arranged along the width direction of the second groove, and the projection of at least one of the second grooves in the groove group along the thickness direction of the first wall portion is located in the predetermined pressure relief area and is located between the opening end and the non-opening end along the width direction of the second groove, and the width direction of the second groove is perpendicular to the thickness direction of the first wall portion.

8. The battery cell according to claim 7, wherein, The projection of at least one of the second grooves in the groove group along the thickness direction of the first wall portion does not overlap with the projection of the predetermined pressure relief area along the thickness direction of the first wall portion.

9. The battery cell according to claim 8, wherein, At least one of the second grooves in the groove group is a first guiding groove, the projection of the first guiding groove along the thickness direction of the first wall portion does not overlap with the projection of the predetermined pressure relief area along the thickness direction of the first wall portion, the first guiding groove is spaced apart from the first groove along the width direction of the first guiding groove, and the two ends of the projection of the first guiding groove along the thickness direction of the first wall portion along the extending direction respectively extend out of the two ends of the first groove.

10. The battery cell according to claim 7, wherein, The projections of all the second grooves in the groove group along the thickness direction of the first wall portion are located in the predetermined pressure relief area and are located between the opening end and the non-opening end along the width direction of the second groove.

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

12. The battery cell according to any one of claims 1-11, wherein, The first groove defines a plurality of the predetermined pressure relief areas.

13. The battery cell according to any one of claims 1-12, wherein, The first wall portion is a rectangular wall portion, and a plurality of the second grooves in the groove group are arranged at intervals along the width direction of the first wall portion.

14. The battery cell according to any one of claims 1-13, wherein, Along the thickness direction of the first wall portion, the pressure relief component has opposite first and second surfaces. The first groove is recessed from the first surface towards the direction close to the second surface, and the second groove is recessed from the second surface towards the direction close to the first surface.

15. The battery cell according to any one of claims 1-13, wherein, Along the thickness direction of the first wall portion, the pressure relief component has opposite first and second surfaces. Both the first groove and the second groove are recessed from the first surface towards the direction close to the second surface.

16. The battery cell according to claim 14 or 15, wherein, The first surface is the surface of the pressure relief component facing the outside of the battery cell, and the second surface is the surface of the pressure relief component facing the inside of the battery cell.

17. The battery cell according to any one of claims 14-16, wherein, The first groove includes multiple levels of grooves arranged in sequence along the direction from the first surface to the second surface. Along the thickness direction of the first wall portion, in adjacent two levels of grooves, the level of groove farther from the first surface is arranged on the groove bottom surface of the level of groove closer to the first surface.

18. The battery cell according to any one of claims 1-17, wherein, The first groove includes a plurality of groove segments, and the plurality of groove segments are connected. The plurality of groove segments jointly define at least one of the predetermined pressure relief areas.

19. The battery cell according to claim 18, wherein, The plurality of groove segments include a first groove segment and a second groove segment. The first groove segment is connected to the second groove segment, and the first groove segment and the second groove segment jointly define at least one of the predetermined pressure relief areas.

20. The battery cell according to claim 18, wherein, The plurality of groove segments include a first groove segment, a second groove segment, and a third groove segment. The second groove segment and the third groove segment are arranged oppositely. A plurality of the second grooves in the groove group are located on the same side of the first groove segment in the width direction. The first groove segment connects the second groove segment and the third groove segment, and the first groove segment, the second groove segment, and the third groove segment jointly define at least one of the predetermined pressure relief areas.

21. The battery cell according to claim 20, wherein, The connection position of the second groove segment and the first groove segment deviates from both ends of the second groove segment, and the connection position of the third groove segment and the first groove segment deviates from both ends of the third groove segment, so that the predetermined pressure relief areas are formed on both sides of the first groove segment.

22. The battery cell according to claim 18, wherein, The groove segment extends along a straight or arc trajectory.

23. The battery cell according to any one of claims 1-17, wherein, The first groove extends along an arc trajectory.

24. The battery cell according to any one of claims 1-23, wherein, The second groove extends along a straight trajectory.

25. The battery cell according to any one of claims 1-24, wherein, The pressure relief component is integrally formed with the first wall portion.

26. The battery cell according to claim 25, wherein, The first groove is formed by stamping on the first wall portion; and / or, the second groove is formed by stamping on the first wall portion.

27. The battery cell according to any one of claims 1-24, wherein, The pressure relief component is separately provided from the first wall portion, and the pressure relief component is installed on the first wall portion.

28. The battery cell according to any one of claims 1-27, wherein, The housing includes: A housing body, with an opening formed at at least one end; An end cover, corresponding to the opening one by one, and the end cover closes the opening; Wherein, at least one of the end covers is the first wall portion.

29. The battery cell according to any one of claims 1-27, wherein, The housing includes: A housing body, with an opening formed at at least one end; An end cover, corresponding to the opening one by one, and the end cover closes the opening; Wherein, at least one of the wall portions of the housing body is the first wall portion.

30. The battery cell according to claim 29, wherein, Only one end of the housing body is formed with the opening, and the wall portion of the housing body opposite to the end cover is the first wall portion.

31. The battery cell according to claim 29, wherein, Openings are formed at both opposite ends of the housing body.

32. The battery cell according to any one of claims 1-31, wherein, The material of the pressure relief component includes steel material.

33. The battery cell according to claim 32, wherein, The steel material is carbon steel or stainless steel.

34. The battery cell according to any one of claims 1-31, wherein, The material of the pressure relief component includes aluminum alloy.

35. The battery cell according to claim 34, wherein, The aluminum alloy includes the following components by mass percentage: aluminum ≥ 99.6%, copper ≤ 0.05%, iron ≤ 0.35%, magnesium ≤ 0.03%, manganese ≤ 0.03%, silicon ≤ 0.25%, titanium ≤ 0.03%, vanadium ≤ 0.05%, zinc ≤ 0.05%, and other single elements ≤ 0.03%.

36. The battery cell according to claim 34, wherein, The aluminum alloy includes the following components by mass percentage: aluminum ≥ 96.7%, 0.05% ≤ copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other single element components ≤ 0.05%, and total other element components ≤ 0.15%.

37. A battery, comprising a battery cell as described in any one of claims 1 - 36.

38. An electrical device, comprising a battery cell as described in any one of claims 1 - 36, wherein the battery cell is used to supply electrical energy to the electrical device.

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