Battery monomer, battery and electric equipment

Abstract

The embodiment of the utility model provides a battery monomer, a battery and electric equipment. The battery monomer comprises a shell and a pressure relief component, the shell comprises a first wall part, the pressure relief component is arranged on the first wall part, the pressure relief component comprises a first groove, the first groove defines at least one preset pressure relief area, and the pressure relief component is configured to be capable of cracking along at least one part of the first groove when the battery monomer is subjected to pressure relief. The pressure relief component further comprises groove sets, the groove sets are in one-to-one correspondence with the preset pressure relief areas, each groove set comprises a plurality of second grooves, the second grooves are formed in the width direction of the second grooves at intervals, and the second grooves are configured to guide at least one part of the preset pressure relief areas to turn over so as to open at least one part of the preset pressure relief areas. The plurality of second grooves can help the predetermined pressure relief area to turn over, so that the predetermined pressure relief area is easier to turn over, the turning difficulty of the predetermined pressure relief area is reduced, the risk of fire or explosion during thermal runaway of the single battery is reduced, and the reliability of the single battery is improved.

Description

Technical Field

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

[0002] In recent years, new energy vehicles have developed by leaps and bounds. In the field of electric vehicles, power batteries, as the power source of electric vehicles, play an irreplaceable and important role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also growing. As the demand for batteries increases, higher requirements are placed on the reliability of battery cells. Therefore, how to improve the reliability of battery cells is an urgent problem to be solved in battery technology. Utility Model Content

[0003] 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.

[0004] 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 also comprises a groove group, the groove groups correspond one-to-one to the predetermined pressure relief areas, each groove group comprises a plurality of second grooves, the plurality of second grooves are spaced apart along a 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.

[0005] In the above technical solution, the pressure relief component includes a first groove, so that the pressure relief component can be split along at least a part of the first groove when the battery cell is depressurized, so as to release the internal pressure of the battery cell. The pressure relief component also includes a groove group, and 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 arranged at intervals along the width direction of the second groove. The plurality of second grooves in the groove group can help the predetermined pressure relief area to flip, making the flipping of the predetermined pressure relief area easier, reducing the flipping difficulty of the predetermined pressure relief area, so that the predetermined pressure relief area can be opened more quickly when the pressure relief component is split along the first groove, reducing the risk of fire or explosion when the battery cell is thermally runaway, thereby effectively improving the reliability of the battery cell.

[0006] In some embodiments, the predetermined pressure relief zone has an open end and a non-open end, and the open end and the non-open end are arranged relatively 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 along the direction from the non-open end to the open end. In 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 along the direction from the non-open end to the open end, it is conducive to realizing that the portion of the predetermined pressure relief zone located between a second groove close to 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.

[0007] In some embodiments, the maximum groove depth of the plurality of second grooves in the groove group gradually increases in the direction from the non-open end to the open end. During the production process, the plurality of second grooves in the groove group can be processed in the order of gradually increasing the depth in the direction from the non-open end to the open end, so as to achieve that 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.

[0008] In some embodiments, the minimum residual thickness of the first groove is less than the minimum residual thickness of the second groove, so that the strength of the residual portion of the first groove is less than the strength of the residual portion of the second groove, so that the pressure relief component can be preferentially split along the first groove to achieve rapid opening of the predetermined pressure relief area.

[0009] In some embodiments, the minimum residual thickness of the first groove is D1, 0.1mm≤D1≤0.5mm. D1≥0.1mm makes the residual part of the first groove have sufficient strength, reduces the risk of the pressure relief component cracking along the first groove in advance during the long-term cycle use of the battery cell, and improves the service life of the battery cell; D1≤0.5mm makes the pressure relief component crack along the first groove more timely when the battery cell is in thermal runaway, reducing the risk of fire or explosion of the battery cell.

[0010] 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 processed deeper than the depth of the second groove, which reduces the difficulty of achieving the minimum residual thickness of the first groove being less than the minimum residual thickness of the second groove.

[0011] In some embodiments, the first groove has two ends, the line connecting the two ends is the first line, the first groove is connected to the first line and together encloses a predetermined pressure relief zone; the predetermined pressure relief zone has an open end and a non-open end, the first line is located at the non-open end, the open end and the non-open end are arranged relatively along the width direction of the second groove, and the projection of at least one second groove in the groove group along the thickness direction of the first wall is located in the predetermined pressure relief zone, and is located between the open end and the non-open 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. In this way, at least two areas of the predetermined pressure relief zone are flipped, thereby reducing the area swept by the predetermined pressure relief zone when flipping, reducing the flipping space required for the predetermined pressure relief zone, reducing the risk of interference between the predetermined pressure relief zone and external components, and improving the reliability of the battery cell.

[0012] 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 is in thermal runaway, so as to increase 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, improve the flatness of the outer surface of the shell in the width direction of the second groove, and 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.

[0013] 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 portion does not overlap with the projection of the predetermined pressure relief zone along the thickness direction of the first wall portion, the first guide groove and the first groove are arranged at intervals along the width direction of the first guide groove, and the projection of the first guide groove along the thickness direction of the first wall portion extends out of the two ends of the first groove at both ends along the extension direction. The first guide groove is made longer, and the auxiliary flipping effect of the first guide groove on the predetermined pressure relief zone is enhanced. In addition, this structure can also improve the separation effect of the first guide groove on the surface of the shell in the width direction of the first guide groove and the first groove, improve the absorption effect of the first guide groove on the excess material extruded when the first groove is formed, further improve the flatness of the outer surface of the shell in the width direction of the first guide groove, and can improve the blocking effect of the first guide groove on the deformation energy of the shell when the shell is subjected to internal and external impact forces, further reducing the risk of the predetermined pressure relief zone opening in advance due to the expansion of the battery cell.

[0014] In some embodiments, the projections of all the second grooves in the groove group along the thickness direction of the first wall are located in the predetermined pressure relief area, and along the width direction of the second grooves are located between the open end and the non-open end. In this way, more areas of the predetermined pressure relief area are turned over, further reducing the area swept by the predetermined pressure relief area when turning over, and reducing the turning space required for the predetermined pressure relief area.

[0015] In some embodiments, along the thickness direction of the first wall portion, the projection of the second groove does not overlap with the projection of the first groove, thereby reducing the mutual influence between the first groove and the second groove during the processing and reducing the risk of the first groove and the second groove being connected to each other during the processing.

[0016] In some embodiments, the first groove defines a plurality of predetermined pressure relief areas. When the battery cell is in thermal runaway, the plurality of predetermined pressure relief areas can be opened, and when the total pressure relief area of ​​the pressure relief component is constant, the opening rate of the predetermined pressure relief areas can be increased, and pressure relief can be achieved more quickly.

[0017] In some embodiments, the first wall portion is a rectangular wall portion, and the plurality of second grooves in the groove group are arranged at intervals along the width direction of the first wall portion. When the first wall portion is deformed due to the expansion of the battery cell, the deformation of the first wall portion in the width direction is smaller than that in the length direction of the first wall portion. The plurality of second grooves in the groove group are arranged at intervals along the width direction of the first wall portion, which can reduce the influence of the deformation of the first wall portion on the second grooves and reduce the risk of fatigue cracking of the pressure relief component along the second grooves during the normal cycle life of the battery cell.

[0018] In some embodiments, along the thickness direction of the first wall portion, the pressure relief component has a first surface and a second surface opposite to each other, the 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 respectively located on both sides of the pressure relief component along the thickness direction of the first wall portion, so that the first groove and the second groove can be processed on both sides of the pressure relief component, which is conducive to reducing the mutual influence of the first groove and the second groove during the processing.

[0019] In some embodiments, along the thickness direction of the first wall portion, the pressure relief component has a first surface and a second surface opposite to each other, and the first groove and the second groove are both recessed from the first surface toward the second surface. In this way, the first groove and the second groove are arranged on the same side of the pressure relief component in the thickness direction, which makes it easier to process the first groove and the second groove on the pressure relief component, and the first groove and the second groove can be processed without turning the pressure relief component over, which is conducive to optimizing the production rhythm of the battery cell.

[0020] 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. In the case where the first groove is set on the first surface, the first groove is set on the outside of the pressure relief component, which is convenient for processing and forming the first groove on the outside of the shell, which is conducive to reducing the difficulty of forming the first groove, so as to improve the production efficiency of the battery cell. In the case where the second groove is set on the first surface, the second groove is set on the outside of the pressure relief component, which is convenient for processing and forming the second groove on the outside of the shell, which is conducive to reducing the difficulty of forming the second groove. In the case where the second groove is set on the second surface, the second groove is set on the inside of the pressure relief component. On the one hand, when the predetermined pressure relief area is turned outward and opened, the two groove sides in the width direction of the second groove are not easy to abut against each other, which is conducive to increasing the opening area of ​​the predetermined pressure relief area; on the other hand, the second groove is not exposed to the outside of the battery cell, reducing the risk of oxidation and corrosion of the pressure relief component in the second groove area.

[0021] In some embodiments, the first groove includes multiple grooves arranged in sequence along the direction from the first surface to the second surface, and along the thickness direction of the first wall, in two adjacent grooves, the first groove away from the first surface is arranged at the groove bottom surface of the first groove close to the first surface. By arranging the first groove as multiple grooves along the thickness direction of the first wall, when forming the first groove, each level of groove can be processed one by one along the direction from the first surface to the second surface, thereby reducing the forming depth of each level of groove, reducing the forming force on the pressure relief component when forming the first groove, and reducing the risk of the pressure relief component being damaged when forming the first groove.

[0022] In some embodiments, the first groove includes a plurality of groove segments, the plurality of groove segments are connected, and the plurality of groove segments together define at least one predetermined pressure relief area. A predetermined pressure relief area with a larger area can be defined by the plurality of groove segments, which is conducive to increasing the pressure relief area of ​​the battery cell.

[0023] In some embodiments, the plurality of slot sections include a first slot section and a second slot section, the first slot section is connected to the second slot section, and the first slot section and the second slot section jointly define at least one predetermined pressure relief area. The first groove structure of this structure is simple, and the position where the first slot section is connected to the second slot section has a greater stress concentration factor, is weaker, and is more likely to crack, so that when the battery cell thermal runaway occurs, the pressure relief component can quickly crack from the first slot section and the second slot section after cracking from the position where the first slot section is connected to the second slot section, so that the predetermined pressure relief area is opened more quickly to relieve pressure in time.

[0024] 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 are arranged opposite to each other, the plurality of second grooves in the slot group are located on the same side of the first slot segment in the width direction, the first slot segment connects the second slot segment and the third slot segment, and the first slot segment, the second slot segment, and the third slot segment jointly define at least one predetermined pressure relief area. The first groove with such a structure makes the intersection position of the first slot segment and the second slot segment and the connection position of the first slot segment and the third slot segment weaker, and is easier to crack and open the predetermined pressure relief area for pressure relief, and can further increase the opening area of ​​the predetermined pressure relief area, thereby increasing the pressure relief area of ​​the battery cell and improving the pressure relief rate of the battery cell.

[0025] In some embodiments, the connection position of the second groove section and the first groove section deviates from the two ends of the second groove section, and the connection position of the third groove section and the first groove section deviates from the two ends of the third groove section, so that predetermined pressure relief areas are formed on both sides of the first groove section. In this way, the first groove section of the first groove is located between the two predetermined pressure relief areas, and after the pressure relief component is split along the first groove section, the two predetermined pressure relief areas can be opened in a split manner to relieve pressure when the battery cell is relieved of pressure, so that the two predetermined pressure relief areas can be opened quickly, which is conducive to improving the pressure relief rate of the battery cell.

[0026] In some embodiments, the groove segment extends along a straight line or an arc track. If the groove segment extends along a straight line track, the groove segment is a straight groove, which can reduce the difficulty of forming the groove segment. If the groove segment extends along an arc track, the groove segment is an arc groove, and the pressure relief component is more likely to split along the groove segment when the battery cell is depressurized, so that the predetermined pressure relief area is opened more quickly.

[0027] In some embodiments, the first groove extends along an arc track. The first groove of this structure only includes one groove segment, which simplifies the structure of the first groove.

[0028] 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.

[0029] In some embodiments, the pressure relief component is integrally formed with the first wall portion, so that the first groove and the second groove can be directly formed on the first wall portion to form an integrated pressure relief structure, which has higher reliability, saves the installation process of the pressure relief component, and has better economy.

[0030] In some embodiments, the first groove is stamped and formed on the first wall; and / or the second groove is stamped and formed on the first wall. If the first groove is stamped and formed on the first wall, the first groove is formed in a simple manner, which is conducive to reducing the production cost of the battery cell. If the second groove is stamped and formed on the first wall, the second groove is formed in a simple manner, which is conducive to reducing the production cost of the battery cell.

[0031] In some embodiments, the pressure relief component is separately arranged from the first wall portion, and the pressure relief component is installed on the first wall portion. The pressure relief component is a component independent of the housing, and the pressure relief component and the housing can be produced and assembled separately, with low production difficulty and high efficiency.

[0032] In some embodiments, the housing includes a shell and an end cover, at least one end of the shell is formed with an opening, the end cover corresponds to the opening one by one, and the end cover closes the opening; wherein at least one end cover is a first wall portion. This allows at least one end cover to have a pressure relief function, and the difficulty of forming the first groove and the second groove on the end cover or the difficulty of installing the pressure relief component is lower.

[0033] In some embodiments, the housing includes a shell and an end cover, at least one end of the shell is formed with an opening, the end cover corresponds to the opening one by one, and the end cover closes the opening; wherein at least one wall portion in the shell is a first wall portion. This allows the shell to have a pressure relief function, and when the battery cell is depressurized, the discharge discharged from the inside of the battery cell is unlikely to affect the external components outside the end cover, thereby reducing the risk of external components being damaged by the discharge.

[0034] In some embodiments, the shell has an opening at only one end, and the wall portion of the shell opposite to the end cap is the first wall portion. The shell has an opening at one end, which makes the structure of the entire battery cell simpler. The first wall portion is the wall portion of the shell opposite to the end cap, which can achieve directional pressure relief from the bottom of the shell.

[0035] In some embodiments, openings are formed at both opposite ends of the housing. The housing is a structure with openings formed at both opposite ends, and the electrode assembly can be assembled into the housing through any opening, which can reduce the difficulty of assembling the battery cell and improve the assembly quality of the battery cell. The housing of this structure can be made longer in length (openings are formed at both ends of the housing in the length direction), which is conducive to increasing the capacity of the battery cell.

[0036] In some embodiments, the material of the pressure relief component includes steel. Steel has the characteristic of high strength, and the pressure relief component made of steel has better strength. Under the condition of a certain bursting pressure of the battery cell, the pressure relief component can be made thinner to reduce the volume of the pressure relief component.

[0037] In some embodiments, the steel material is carbon steel or stainless steel.

[0038] In some embodiments, the pressure relief component is made of aluminum alloy, which has the characteristics of light weight and good ductility, and it is easier to process the first groove and the second groove on the pressure relief component.

[0039] In some embodiments, the aluminum alloy includes the following components in mass percentage: aluminum ≥ 99.6%, copper ≤ 0.05%, iron ≤ 0.35%, magnesium ≤ 0.03%, manganese ≤ 0.03%, silicon ≤ 0.25%, titanium ≤ 0.03%, vanadium ≤ 0.05%, zinc ≤ 0.05%, and other single elements ≤ 0.03%. This aluminum alloy has lower hardness, better forming ability, reduces the difficulty of processing the first groove and the second groove, is conducive to improving the processing accuracy of the first groove and the second groove, and improves the pressure relief consistency of the pressure relief component.

[0040] In some embodiments, the aluminum alloy includes the following components in percentage by mass: aluminum ≥ 96.7%, 0.05% ≤ copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other single element components ≤ 0.05%, and other elements in total ≤ 0.15%. The pressure relief component made of such an aluminum alloy has higher hardness, greater strength, and good anti-destruction ability.

[0041] In a second aspect, an embodiment of the present application provides a battery, comprising a battery cell provided in any one embodiment of the first aspect.

[0042] 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

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0045] Figure 2 An exploded view of a battery provided for some embodiments of the present application;

[0046] Figure 3 An exploded view of a battery cell provided for some embodiments of the present application;

[0047] Figure 4 for Figure 3 An assembly diagram of a battery cell is shown;

[0048] Figure 5 for Figure 4 A partial view of the housing is shown;

[0049] Figure 6 for Figure 5 AA section view of the housing shown;

[0050] Figure 7 for Figure 6 A partial enlarged view of point B in the middle;

[0051] Figure 8 for Figure 6 A cross-sectional view of the housing shown (with a portion of the predetermined pressure relief area opened);

[0052] Fig. 9 for Figure 6 A cross-sectional view of the housing shown (with the predetermined pressure relief area fully opened);

[0053] Fig.10 A partial view of a housing provided for some embodiments of the present application;

[0054] Fig.11 A cross-sectional view of a housing provided for some embodiments of the present application;

[0055] Fig.12 A partial view of a housing provided for some other embodiments of the present application;

[0056] Fig.13 for Fig.12 A CC section view of the housing shown;

[0057] Fig.14 for Fig.13 A partial enlarged view of point D in the middle;

[0058] Fig.15 A partial view of a housing provided for some further embodiments of the present application;

[0059] Fig.16 for Fig.15 FF section view of the housing shown;

[0060] Fig.17 A partial view of a housing provided for yet other embodiments of the present application;

[0061] Fig.18 for Fig.17 GG section view of the housing shown;

[0062] Fig.19 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 for some embodiments of the present application;

[0063] Fig. 20 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;

[0064] Fig.21An exploded view of a housing (an opening is formed at one end of the housing, and the housing includes a first wall portion) provided for some embodiments of the present application;

[0065] Fig. 22 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 for some other embodiments of the present application;

[0066] Fig.23 An exploded view of a battery cell provided for some other embodiments of the present application.

[0067] Icons: 1-housing; 11-housing; 12-end cover; 13-first wall; 131-pressure relief hole; 14-second wall; 15-third wall; 2-electrode assembly; 21-ear; 3-electrode terminal; 4-current collecting member; 5-insulating member; 6-pressure relief member; 61-first groove; 611-groove section; 611a-first groove section; 611b-second groove section; 611c-third groove section; 62-groove group; 621-second groove; 621 a-first guide groove; 63-predetermined pressure relief area; 631-open end; 632-non-open 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

[0068] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0069] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0070] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0071] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0072] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0073] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0074] The term "plurality" used in the present application refers to two or more (including two).

[0075] 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.

[0076] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, and the like.

[0077] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to reduce the risk of short circuit between the positive and negative electrodes, while allowing active ions to pass through.

[0078] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0079] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0080] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0081] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries can also be used. These positive electrode active materials can be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM622 )、LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and its modified compounds, etc.

[0082] In some embodiments, the positive electrode may be a foamed metal. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, or a foamed alloy. When the foamed metal is used as the positive electrode, the positive electrode active material may not be provided on the surface of the foamed metal, but of course, the positive electrode active material may also be provided. As an example, a lithium source material, potassium metal, or sodium metal may be filled or / and deposited in the foamed metal, and the lithium source material is lithium metal and / or a lithium-rich material.

[0083] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0084] As an example, the negative electrode current collector may be a metal foil, a foamed metal or a composite current collector. For example, as the metal foil, aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc., treated with silver surface, may be used. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, etc. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0085] 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.

[0086] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0087] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0088] 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.

[0089] In some embodiments, the separator is a separator membrane, which can be any known porous separator membrane with good chemical stability and mechanical stability.

[0090] As an example, the material of the separator may include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or may be attached to the surface of the positive and negative electrodes.

[0091] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0092] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The electrolyte can be liquid, gel or solid. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0093] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0094] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0095] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0096] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0097] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0098] 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.

[0099] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0100] 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.

[0101] In some embodiments, the electrode assembly is a laminate structure.

[0102] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

[0103] 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.

[0104] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded sections that are stacked.

[0105] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0106] As an example, the separator may be disposed continuously, and may be disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0107] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0108] In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0109] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0110] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery.

[0111] 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.

[0112] 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.

[0113] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0114] 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.

[0115] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0116] The development of battery technology must take into account many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery safety must also be considered.

[0117] In order to improve the reliability of the battery cell, a pressure relief component can generally be provided in the battery cell. The pressure relief component can be a part of the outer shell of the battery cell or a component installed on the outer shell. When the battery cell thermally runs away, the pressure inside the battery cell can be released through the pressure relief component.

[0118] For a general battery cell, a first groove can be provided on the pressure relief component, and at least one predetermined pressure relief area is defined by the first groove. When the pressure of the battery cell is relieved, the pressure relief component can be split along at least a portion of the first groove, so that the predetermined pressure relief area of ​​the pressure relief component can be opened to release the pressure inside the battery cell. In such a battery cell, when the battery cell is thermally runaway, the predetermined pressure relief area is difficult to open during the process of the pressure relief component splitting along the first groove, which affects the opening speed of the predetermined pressure relief area, and the battery cell is prone to fire or explosion, and the reliability of the battery cell is poor.

[0119] 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 groove group on the pressure relief component, the groove group 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 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.

[0120] In such a battery cell, the multiple second grooves in the groove group can help the predetermined pressure relief zone to flip, making the flipping of the predetermined pressure relief zone easier and reducing the difficulty of flipping the predetermined pressure relief zone, so that the predetermined pressure relief zone can be opened 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.

[0121] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical equipment using batteries.

[0122] Electrical equipment can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles and spacecrafts, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc.

[0123] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0124] Please refer to Figure 1 , Figure 1 The schematic diagram of the structure of the vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 is provided with a battery 100 inside, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000, for example, the battery 100 can be used as an operating power source of the vehicle 1000.

[0125] The vehicle 1000 may further include a controller 200 and a motor 300 , wherein the controller 200 is used to control the battery 100 to supply power to the motor 300 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1000 .

[0126] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0127] Please refer to Figure 2 , Figure 2 The exploded view of the battery 100 provided in some embodiments of the present application. The battery 100 includes a battery cell 10 and a box body 20, and the battery cell 10 is accommodated in the box body 20.

[0128] Among them, the box body 20 is a component for accommodating the battery cell 10. The box body 20 provides a storage space for the battery cell 10. The box body 20 can adopt a variety of structures. In some embodiments, the box body 20 may include a first part 201 and a second part 202, and the first part 201 and the second part 202 cover each other to define a storage space for accommodating the battery cell 10. The first part 201 and the second part 202 may be in a variety of shapes, such as a rectangular parallelepiped, a cylindrical shape, etc. The first part 201 may be a hollow structure with one side open, and the second part 202 may also be a hollow structure with one side open, and the open side of the second part 202 covers the open side of the first part 201, so as to form a box body 20 with a storage space. It is also possible that the first part 201 is a hollow structure with one side open, and the second part 202 is a plate-like structure, and the second part 202 covers the open side of the first part 201, so as to form a box body 20 with a storage space. The first part 201 and the second part 202 can be sealed by a sealing element, and the sealing element can be a sealing ring, a sealant, etc.

[0129] In the battery 100, there may be one or more battery cells 10. If there are more than one battery cell 10, the battery cells 10 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the battery cells 10 are both connected in series and in parallel. The battery modules may be connected in series, in parallel, or in a mixed connection to form a battery module, and then the battery modules may be connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 20. Alternatively, all the battery cells 10 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by all the battery cells 10 may be accommodated in the box 20.

[0130] Please refer to Figure 3 , Figure 3 An exploded view of a battery cell 10 provided in some embodiments of the present application. The battery cell 10 may include a housing 1 and an electrode assembly 2, wherein the electrode assembly 2 is accommodated in the housing 1.

[0131] 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 .

[0132] The shell 11 is a component for accommodating the electrode assembly 2. The shell 11 may be a hollow structure with an opening formed at one end, or a hollow structure with openings formed at opposite ends. The shell 11 may be in various shapes, such as a cylindrical shape, a rectangular parallelepiped shape, etc. The shell 11 may be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0133] The end cap 12 is a component that closes the opening of the shell 11 to isolate the internal environment of the battery cell 10 from the external environment. The end cap 12 and the shell 11 together define a receiving space for accommodating the electrode assembly 2, the electrolyte and other components. The end cap 12 can be connected to the shell 11 by welding or crimping to close the opening of the shell 11. The shape of the end cap 12 can be adapted to the shape of the shell 1. For example, the shell 11 is a rectangular parallelepiped structure, and the end cap 12 is a rectangular plate structure adapted to the shell 1. For another example, the shell 11 is a cylindrical structure, and the end cap 12 is a circular plate structure adapted to the shell 11. The material of the end cap 12 can also be a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, plastic, etc. The material of the end cap 12 and the shell 11 can be the same or different.

[0134] In the embodiment where the housing 11 is opened at one end, one end cap 12 may be provided. In the embodiment where the housing 11 is opened at two opposite ends, two end caps 12 may be provided, and the two end caps 12 respectively close the two openings of the housing 11, and the two end caps 12 and the housing 11 together define a receiving space.

[0135] In some embodiments, the battery cell 10 may further include an electrode terminal 3, which is disposed on the housing 1 and is used to electrically connect to the tab 21 of the electrode assembly 2 to input or output the electrical energy of the battery cell 10. The electrode terminal 3 may be disposed on the shell 11 of the housing 1 or on the end cover 12 of the housing 1. The electrode terminal 3 and the tab 21 may be directly connected, for example, the electrode terminal 3 and the tab 21 are directly welded. The electrode terminal 3 and the tab 21 may also be indirectly connected, for example, the electrode terminal 3 and the tab 21 are indirectly connected through a current collecting member 4. The current collecting member 4 may be a metal conductor, for example, copper, iron, aluminum, steel, aluminum alloy, etc.

[0136] As an example, Figure 3 As shown, an opening is formed at one end of the shell 11, and there is one end cap 12 in the shell 1, and one end cap 12 closes one opening of the shell 11. Two electrode terminals 3 are arranged on the end cap 12, and the two electrode terminals 3 are respectively a positive electrode terminal 3 and a negative electrode terminal 3. A positive electrode ear 21 and a negative electrode ear 21 are formed at one end of the electrode assembly 2 facing the end cap 12, and the positive electrode terminal 3 is connected to the positive electrode ear 21 through a current collecting member 4, and the negative electrode terminal 3 is connected to the negative electrode ear 21 through another current collecting member 4.

[0137] In some embodiments, please refer to Figure 3 The battery cell 10 may further include an insulating member 5, which is a component that separates the housing 11 from the electrode assembly 2, and the insulating member 5 is used to achieve insulation isolation between the housing 11 and the electrode assembly 2. The insulating member 5 is made of insulating material, and the material of the insulating member 5 includes but is not limited to: plastic, rubber, etc.

[0138] As an example, the insulating member 5 is wrapped around the outside of the electrode assembly 2 along the circumferential direction of the opening of the shell 11. The electrode assembly 2 in the shell 1 can be one or more. If there is one electrode assembly 2, the insulating member 5 is wrapped around the electrode assembly 2; if there are multiple electrode assemblies 2, one insulating member 5 can be set corresponding to one electrode assembly 2, and each insulating member 5 is wrapped around one electrode assembly 2, or multiple electrode assemblies 2 can be used as an integral component, and the insulating member 5 is wrapped around the integral component.

[0139] Please refer to Figure 4-Figure 7 , Figure 4 for Figure 3 An assembly diagram of the battery cell 10 is shown; Figure 5 for Figure 4 A partial view of the housing 1 is shown; Figure 6 for Figure 5 AA sectional view of the housing 1 shown; Figure 7 for Figure 6The embodiment of the present application provides a battery cell 10, including a housing 1 and a pressure relief component 6, the housing 1 includes a first wall portion 13, the pressure relief component 6 is arranged on the first wall portion 13, the pressure relief component 6 includes 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 able to split along at least a portion of the first groove 61 when the battery cell 10 is depressurized.

[0140] 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. The plurality of second grooves 621 are arranged at intervals along the width direction of the second grooves 621. The second grooves 621 are configured to guide at least a portion of the predetermined pressure relief area 63 to flip so as to open at least a portion of the predetermined pressure relief area 63.

[0141] The housing 1 may include a plurality of walls, which together define a receiving space inside the housing 1 to accommodate the battery cell 10, electrolyte and other components, which may be current collecting components 4, insulating components 5 and other components. Among the plurality of walls of the housing 1, one wall may be the first wall 13, or a plurality of walls may be the first wall 13. Taking the housing 1 as a rectangular parallelepiped as an example, there are six walls in the housing 1, and one, two, three, four, five or six walls may be the first wall 13. In the housing 1, at least one end cover 12 may be the first wall 13, or at least one wall in the shell 11 may be the first wall 13.

[0142] The pressure relief component 6 is a component in the battery cell 10 for releasing the pressure inside the battery cell 10. The pressure relief component 6 is arranged on the first wall portion 13, and the pressure relief component 6 and the first wall portion 13 may be integrally formed, or the pressure relief component 6 and the first wall portion 13 may be separately arranged, and the pressure relief component 6 is installed on the first wall portion 13. If the pressure relief component 6 and the first wall portion 13 are integrally formed, so that the pressure relief component 6 is at least a part of the first wall portion 13, that is, the first wall portion 13 may be the entire pressure relief component 6, or a part of the first wall portion 13 may be the pressure relief component 6.

[0143] The first groove 61 is a pressure relief groove provided in the pressure relief component 6. When the pressure inside the battery cell 10 reaches the bursting pressure of the pressure relief component 6, the pressure relief component 6 can be split along at least a portion of the first groove 61 to open the predetermined pressure relief area 63. It can be understood that when the battery cell 10 is depressurized, the pressure relief component 6 can be split along the entire first groove 61, or can be split along a portion of the first groove 61 to release the pressure inside the battery cell 10. The first groove 61 can be formed in a variety of ways, such as stamping, milling, etc. The first groove 61 can include at least one groove segment 611, and the cross-section of the groove segment 611 can be in a variety of shapes, such as rectangular, trapezoidal, etc., and the cross-section of the groove segment 611 is perpendicular to the extension direction of the groove segment 611. The shape of the first groove 61 can be various, for example, the first groove 61 is a groove extending along an arc trajectory, and for another example, the first groove 61 includes a plurality of groove segments 611, and the plurality of groove segments 611 can form a U-shape, an H-shape, a V-shape, a Y-shape, an X-shape, a T-shape, etc.

[0144] 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 may be one or more. The predetermined pressure relief area 63 can be opened when the pressure relief component 6 is split along the first groove 61. The predetermined pressure relief area 63 may be triangular, rectangular, trapezoidal, semicircular, etc. Figure 5 In the illustrated embodiment, there are two predetermined pressure relief areas 63 , and the two shaded portions are the two predetermined pressure relief areas 63 .

[0145] The plurality of second grooves 621 in the groove group 62 are arranged at intervals, that is, two adjacent second grooves 621 are spaced apart from each other by a certain distance. As an example, the plurality of second grooves 621 in the groove group 62 are arranged in parallel. The number of second grooves 621 in the groove group 62 may be two, three, four or more. The groove group 62 corresponds to the predetermined pressure relief area 63 one by one. For example, if there are two second grooves 621 in the groove group 62, each predetermined pressure relief area 63 is arranged corresponding to two second grooves 621. The second groove 621 is a flip groove arranged in the pressure relief component 6. When the pressure relief component 6 is cracked along at least a portion of the first groove 61, the second groove 621 can guide at least a portion of the predetermined pressure relief area 63 to flip. That is, the second groove 621 plays a role in helping the predetermined pressure relief area 63 to flip, making it easier for the predetermined pressure relief area 63 to flip toward the outside of the battery cell 10, thereby quickly opening the predetermined pressure relief area 63. The second groove 621 may guide the entire flipping of the predetermined pressure relief area 63, or the second groove 621 may guide only a portion of the predetermined pressure relief area 63 to flip. The flipped portion of the predetermined pressure relief area 63 may flip around the remaining portion of the second groove 621, and the remaining portion of the second groove 621 may 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 part 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 may be less than the minimum residual thickness of the second groove 621, so that the area where the pressure relief component 6 is provided with the first groove 61 is easier to crack than the area where the pressure relief component 6 is provided with the second groove 621. 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 line trajectory. The shape of the cross section of the second groove 621 can be various, such as rectangular, trapezoidal, etc.

[0146] 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 zone 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 zone 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 zone 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 zone 63.

[0147] The second groove 621 and the first groove 61 may be arranged on the same surface of the pressure relief component 6 along the thickness direction X of the first wall, or the second groove 621 and the first groove 61 may be arranged on two opposite surfaces of the pressure relief component 6 along the thickness direction X of the first wall. The plurality of second grooves 621 in the groove group 62 may be arranged on the same surface of the pressure relief component 6 along the thickness direction X of the first wall, or a portion of the plurality of second grooves 621 in the groove group 62 may be arranged on one surface of the pressure relief component 6 along the thickness direction X of the first wall, and another portion may be arranged on another surface of the pressure relief component 6 along the thickness direction X of the first wall.

[0148] As an example, in Figure 4-Figure 7 In the illustrated embodiment, the wall portion of the housing 11 opposite to the end cover 12 is the first wall portion 13, the first wall portion 13 serves as the pressure relief component 6, the first groove 61 and the second groove 621 are respectively arranged on two surfaces of the first wall portion 13 opposite to each other in the thickness direction, the first wall portion 13 is a rectangular wall portion, the length direction Y of the first wall portion, the width direction Z of the first wall portion and the thickness direction X of the first wall portion are perpendicular to each other. The first groove 61 is H-shaped, the second groove 621 extends along a straight line trajectory, the extension direction of the second groove 621 is 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 also 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, and the second wall portion 14 and the third wall portion 15 are arranged opposite to each other along the width direction of the second groove 621. The housing 1 is in a rectangular parallelepiped shape, the thickness direction X of the first wall is parallel to the height direction of the battery cell 10 , the length direction Y of the first wall is parallel to the length direction of the battery cell 10 , and the width direction Z of the first wall is parallel to the thickness direction of the battery cell 10 .

[0149] In this embodiment, the pressure relief component 6 includes a first groove 61, so that the pressure relief component 6 can be split along at least a portion of the first groove 61 when the battery cell 10 is depressurized, thereby releasing the internal pressure of the battery cell 10. The pressure relief component 6 also includes a groove group 62, and the groove group 62 corresponds to the predetermined pressure relief area 63 one by one. 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 plurality of second grooves 621 in the groove group 62 can 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 enabling the predetermined pressure relief area 63 to be opened more quickly when the pressure relief component 6 is split along the first groove 61, thereby reducing the risk of fire or explosion when the battery cell 10 is thermally runaway, thereby effectively improving the reliability of the battery cell 10.

[0150] In some embodiments, please refer to Figure 5-Figure 7The 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. 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.

[0151] 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.

[0152] The minimum residual thickness of the second groove 621 is the minimum thickness of the residual portion of the pressure relief component 6 after the second groove 621 is provided. The residual portion of the second groove 621 may be the groove bottom wall of the second groove 621. The thickness of the residual portion of the second groove 621 may be uniform or non-uniform. If the thickness of the residual portion of the second groove 621 is non-uniform, the thickness of the thinnest position of the residual portion of the second groove 621 is the minimum residual thickness of the second groove 621.

[0153] For example, when there are two second grooves 621 in the groove group 62 , the minimum residual thickness of the second groove 621 far from the open end 631 is greater than the minimum residual thickness of the second groove 621 close to the open end 631 .

[0154] Among the multiple second grooves 621, each second groove 621 can help the portion of the predetermined pressure relief zone 63 located between the second groove 621 and the open end 631 to flip, so that the portion of the predetermined pressure relief zone 63 located between the second groove 621 and the open end 631 can flip around the residual portion 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 portion 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 portion of the predetermined pressure relief zone 63 located between a second groove 621 far away from the open end 631 and the open end 631.

[0155] In some embodiments, the maximum groove depth of the plurality of second grooves 621 in the groove group 62 gradually increases in the direction from the non-open end 632 to the open end 631 .

[0156] The maximum distance between the notch of the second groove 621 and the groove 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.

[0157] For example, when there are two second grooves 621 in the groove group 62 , among the two second grooves 621 , the maximum groove depth of the second groove 621 far from the open end 631 is smaller than the maximum groove depth of the second groove 621 close to the open end 631 .

[0158] 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, thereby achieving a minimum residual thickness of the multiple second grooves 621 in the groove group 62 that gradually decreases from the non-open end 632 to the open end 631.

[0159] In some embodiments, the minimum residual thickness of the first groove 61 is less than the minimum residual thickness of the second groove 621 .

[0160] The minimum residual thickness of the first groove 61 is the minimum thickness of the residual portion of the pressure relief component 6 after the first groove 61 is provided. The residual portion of the first groove 61 may be the bottom wall of the first groove 61. The thickness of the residual portion of the first groove 61 may be uniform or non-uniform. If the thickness of the residual portion of the first groove 61 is non-uniform, the thickness of the thinnest position of the residual portion of the first groove 61 is the minimum residual thickness of the first groove 61.

[0161] 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 .

[0162] In the groove group 62, the minimum residual thicknesses of the plurality of second grooves 621 may be equal or different. In the embodiment where the minimum residual thicknesses of the plurality of second grooves 621 in the groove group 62 gradually decrease from the non-open end 632 to the open end 631, the minimum residual thickness of the first groove 61 is less than the minimum residual thickness of the second groove 621 in the groove group 62 that is closest to the open end 631. Figure 7 As shown, the minimum residual thickness of the first groove 61 is D1, and the minimum residual thickness of the second groove 621 closest to the open end 631 in the groove group 62 (the second groove 621 with the smallest minimum residual thickness in the groove group 62) is D2, and D1<D2.

[0163] In this embodiment, the minimum residual thickness of the first groove 61 is smaller than the minimum residual thickness of the second groove 621, so that the strength of the residual part of the first groove 61 is smaller than the strength of the residual part of the second groove 621, so that the pressure relief component 6 can preferentially split along the first groove 61 to achieve rapid opening of the predetermined pressure relief area 63.

[0164] In some embodiments, the minimum residual thickness of the first groove 61 is D1, and 0.1 mm≤D1≤0.5 mm.

[0165] D1 can be 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.

[0166] 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 prematurely cracking along the first groove 61 during the long-term circulation of the battery cell 10, and improving the service life of the battery cell 10; D1≤0.5mm, so that the pressure relief component 6 can be more promptly cracked along the first groove 61 when the battery cell 10 thermally runs away, reducing the risk of fire or explosion of the battery cell 10.

[0167] In some embodiments, the maximum groove depth of the first groove 61 is greater than the maximum groove depth of the second groove 621 .

[0168] The maximum distance between the notch of the first groove 61 and the groove 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.

[0169] 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 .

[0170] In the groove group 62, the maximum groove depths of the plurality of second grooves 621 may be equal or different. In the embodiment where the maximum groove depths of the plurality of second grooves 621 in the groove group 62 gradually increase in the direction from the non-open end 632 to 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 that is closest to the open end 631. Figure 7 As shown, the maximum groove depth of the first groove 61 is H1, and the maximum groove depth of the second groove 621 closest to the open end 631 in the groove group 62 (the second groove 621 with the largest maximum groove depth in the groove group 62) is H2, and H2

[0171] 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 .

[0172] In some embodiments, please 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 to 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.

[0173] The first connecting line W is a connecting line between the two ends of the first groove 61, and the first connecting line W is a straight line. One first groove 61 may be connected to one first connecting line W and together enclose a predetermined pressure relief area 63, or one first groove 61 may be connected to multiple second connecting lines and together enclose multiple predetermined pressure relief areas 63. As an example, in Figure 5 In the illustrated embodiment, 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 .

[0174] The first groove 61 may include only one groove section 611 or multiple groove sections 611. If the first groove 61 includes only one groove section 611, the groove section 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 sections 611, multiple groove sections 611 and the first connecting line W may be connected end to end in sequence to enclose a predetermined pressure relief area 63.

[0175] 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.

[0176] 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 is located between the open end 631 and the non-open end 632 along the width direction of the second groove 621, so that at least two areas of the predetermined pressure relief area 63 are flipped, thereby 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. The external component can be a wall of the box 20 in the battery 100 opposite to the first wall 13, or a thermal management component in the battery 100 arranged opposite to the first wall 13, and the thermal management component can be a water cooling plate or a heating element.

[0177] Please refer to Figure 8 and Fig. 9 , Figure 8 for Figure 6 A cross-sectional view of the housing 1 (with a portion of the predetermined pressure relief area 63 open); Fig. 9 for Figure 6 The cross-sectional view of the housing 1 (with the predetermined pressure relief area 63 fully opened) is shown. Taking the case that there are two second grooves 621 in the groove group 62 as an example, when the battery cell 10 is depressurized, a part of the predetermined pressure relief area 63 first turns around the remaining part of a second groove 621 close to the open end 631; the predetermined pressure relief area 63 then turns around the remaining part of a second groove 621 away from the open end 631, which effectively reduces the area swept by the predetermined pressure relief area 63 when turning over, and reduces the turning space required for the predetermined pressure relief area 63.

[0178] In some embodiments, please refer to Figure 5 , 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.

[0179] In the groove group 62, the projection of a 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 a 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.

[0180] As an example, in Figure 5In the illustrated embodiment, there are two second grooves 621 in the groove group 62, one of the two second grooves 621 is projected along the thickness direction X of the first wall portion and is located within the predetermined pressure relief area 63, while the other is projected along the thickness direction X of the first wall portion and is located outside the predetermined pressure relief area 63.

[0181] 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 portion does not overlap with the projection of the predetermined pressure relief zone 63 along the thickness direction X of the first wall portion, so that at least one second groove 621 is located outside the predetermined pressure relief zone 63, so that a larger area of ​​the predetermined pressure relief zone 63 can be turned over when the battery cell 10 is in thermal runaway, so as to increase the opening area of ​​the predetermined pressure relief zone 63. In addition, the second groove 621 located outside the predetermined pressure relief zone 63 can absorb the excess material extruded when the first groove 61 is formed, and improve the flatness of the outer surface of the shell 1 in the width direction of the second groove 621 (the outer surface of the second wall portion 14 and the outer surface of the third wall portion 15). The second groove 621 located outside the predetermined pressure relief zone 63 of the second groove 621 can also block the deformation energy of the shell 1 to a certain extent when the shell 1 is subjected to internal and external impact forces, thereby reducing the risk of the predetermined pressure relief zone 63 opening in advance due to the expansion of the battery cell 10.

[0182] 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, and 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.

[0183] 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 portion, and the width direction of the first guide groove 621a is the width direction of the second groove 621. The first guide groove 621a and the first groove 61 are arranged at intervals 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 portion and the projection of the first groove 61 along the thickness direction X of the first wall portion are a certain distance apart 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 portion, or can be located on opposite sides of the pressure relief component 6 along the thickness direction X of the first wall portion.

[0184] 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 .

[0185] In this embodiment, the first guide groove 621a and the first groove 61 are arranged at intervals along the width direction of the first guide groove 621a, and the two ends of the first guide groove 621a extend out of the two ends of the first groove 61, so that the first guide groove 621a is longer, and the auxiliary turning effect of the first guide groove 621a on the predetermined pressure relief area 63 is enhanced. In addition, this structure can also improve the separation effect of the first guide groove 621a on the surface of the shell 1 in the width direction of the first guide groove 621a and the first groove 61, improve the absorption effect of the first guide groove 621a on the excess material extruded when the first groove 61 is formed, further improve the flatness of the outer surface of the shell 1 in the width direction of the first guide groove 621a, and improve the blocking effect of the first guide groove 621a on the deformation energy of the shell 1 when the shell 1 is subjected to internal and external impact forces, and further reduce the risk of the predetermined pressure relief area 63 opening in advance due to the expansion of the battery cell 10.

[0186] In some embodiments, please refer to Fig.10 , Fig.10 Partial view of the housing 1 provided in some embodiments of the present application. The projection of all second grooves 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 is located between the open end 631 and the non-open end 632 along the width direction of the second groove 621 .

[0187] 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.

[0188] In this embodiment, the projection of all the second grooves 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 along the width direction of the second grooves 621 is located at the open end 631 and the non-open end 632, 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.

[0189] In some embodiments, please refer to Figure 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 .

[0190] 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.

[0191] 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 with 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, and reducing the risk of the first groove 61 and the second groove 621 being connected to each other during the processing.

[0192] In some embodiments, the first groove 61 defines a plurality of predetermined pressure relief areas 63 .

[0193] The first groove 61 may define two, three, four or more predetermined pressure relief areas 63. Figure 5 and Fig.10 In the illustrated embodiment, the first groove 61 defines two predetermined pressure relief areas 63 .

[0194] When the battery cell 10 is in thermal runaway, the plurality of predetermined pressure relief areas 63 can be opened. When the total pressure relief area of ​​the pressure relief component 6 is constant, the opening rate of the predetermined pressure relief areas 63 can be increased to achieve faster pressure relief.

[0195] In some embodiments, please refer to Figure 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 arranged at intervals along the width direction Z of the first wall portion.

[0196] As an example, the width direction of the second groove 621 is parallel to the width direction Z of the first wall portion.

[0197] The housing 1 may be in a rectangular parallelepiped shape, and the first wall portion 13 may be any rectangular wall portion in the housing 1. The first wall portion 13 is a rectangular wall portion, that is, the first wall portion 13 is substantially in a rectangular shape when viewed along the thickness direction X of the first wall portion. The length of the first wall portion 13 is greater than the width of the first wall portion 13.

[0198] 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 spaced apart 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.

[0199] In some embodiments, please 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 second surface 65 , and the second groove 621 is recessed from the second surface 65 toward the first surface 64 .

[0200] The first surface 64 and the second surface 65 are two surfaces of the pressure relief component 6 that are opposite to each other along the thickness direction X of the first wall portion. The first groove 61 is recessed from the first surface 64 to the direction close to the second surface 65, that is, the first groove 61 is arranged on the first surface 64; the second groove 621 is recessed from the second surface 65 to the direction close to the first surface 64, that is, the second groove 621 is arranged on the second surface 65. One of the first surface 64 and the second surface 65 may be the outer surface of the pressure relief component 6, and the other may be the inner surface of the pressure relief component 6. The outer surface of the pressure relief component 6 faces the outside of the battery cell 10, and the inner surface of the pressure relief component 6 faces the inside of the battery cell 10. The first surface 64 and the second surface 65 may be planes, and the first surface 64 and the second surface 65 may be arranged in parallel or at a non-zero angle.

[0201] As an example, in Figure 6 In the illustrated embodiment, 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.

[0202] 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 reduce the mutual influence between the first groove 61 and the second groove 621 during the processing.

[0203] In some embodiments, please refer to Fig.11 , Fig.11 The cross-sectional view of the housing 1 provided in some embodiments of the present application. Along the thickness direction X of the first wall portion, the pressure relief component 6 has a first surface 64 and a second surface 65 opposite to each other, and the first groove 61 and the second groove 621 are both recessed from the first surface 64 to the direction close to the second surface 65 .

[0204] 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 disposed 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.

[0205] In this embodiment, the first groove 61 and the second groove 621 are both recessed from the first surface 64 toward the direction close to 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.

[0206] In some embodiments, please refer to Figure 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 .

[0207] 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 .

[0208] Please refer to Figure 6 and Fig.11 When the first groove 61 is disposed on the first surface 64, the first groove 61 is disposed on the outer side of the pressure relief component 6, which facilitates the first groove 61 to be formed on the outer side of the housing 1, thereby reducing the difficulty of forming the first groove 61 and improving the production efficiency of the battery cell 10. Fig.11 When the second groove 621 is disposed on the first surface 64, the second groove 621 is disposed on the outside of the pressure relief component 6, which facilitates the processing and forming of the second groove 621 on the outside of the housing 1, and helps to reduce the difficulty of forming the second groove 621. Figure 6 and Fig.11 When the second groove 621 is arranged on the second surface 65, the second groove 621 is arranged on the inner side of the pressure relief component 6. On the one hand, when the predetermined pressure relief area 63 is turned outward and opened, the two groove side surfaces in the width direction of the second groove 621 are not easy to abut against each other, which is beneficial to increase the opening area of ​​the predetermined pressure relief area 63; on the other hand, the second groove 621 is not exposed to the outside of the battery cell 10, reducing the risk of oxidation corrosion of the pressure relief component 6 in the second groove 621 area.

[0209] In some embodiments, please refer to Figure 12-14 , Fig.12Partial views of the housing 1 provided for other embodiments of the present application; Fig.13 for Fig.12 The CC cross-sectional view of the housing 1 is shown; Fig.14 for Fig.13 The first groove 61 includes a plurality of grooves arranged in sequence along the direction from the first surface 64 to the second surface 65 , and along the thickness direction X of the first wall portion, in two adjacent grooves, the first groove away from the first surface 64 is arranged at the groove bottom surface of the first groove close to the first surface 64 .

[0210] The first groove 61 is a stepped groove, and the first groove 61 can be a two-level groove, a three-level groove, a four-level groove, a five-level groove, etc. Along the direction from the first surface 64 to the second surface 65, the groove width of each level of the groove gradually decreases. It can be understood that in the multi-level groove of the first groove 61, the first-level groove with the largest groove width is set on the first surface 64. Take the first groove 61 as a two-level groove as an example, the two-level grooves are respectively the first-level groove and the second-level groove. During processing, the first-level groove with a larger width can be processed on the first surface 64 first, and then the second-level groove with a smaller width can be processed on the groove bottom surface of the first-level groove.

[0211] In the embodiment where the first groove 61 includes a plurality of groove sections 611, it can be understood that each groove section 611 is a multi-stage groove, that is, each groove section 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.

[0212] 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.

[0213] In some embodiments, please refer to Figure 12-14 The first groove 61 includes a plurality of groove sections 611 , the plurality of groove sections 611 are connected, and the plurality of groove sections 611 together define at least one predetermined pressure relief area 63 .

[0214] The slot segment 611 may extend along a straight trajectory or a non-straight trajectory. The non-straight trajectory may be an arc trajectory, a parabolic trajectory, etc. A plurality of slot segments 611 may jointly define a predetermined pressure relief zone 63, for example, a plurality of slot segments 611 may form a V-shaped slot or a U-shaped slot, etc.; a plurality of slot segments 611 may jointly define a plurality of predetermined pressure relief zones 63, for example, a plurality of slot segments 611 may form an H-shaped slot, an X-shaped slot, a Y-shaped slot, etc., wherein the H-shaped slot defines two predetermined pressure relief zones 63, the X-shaped slot defines four predetermined pressure relief zones 63, and the Y-shaped slot defines three predetermined pressure relief zones 63.

[0215] In the first groove 61, the minimum residual thicknesses of the plurality of 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 plurality of groove segments 611 is the minimum residual thickness of the first groove 61.

[0216] In this embodiment, a predetermined pressure relief area 63 with a larger area can be defined by a plurality of groove sections 611 , which is beneficial to increase the pressure relief area of ​​the battery cell 10 .

[0217] In some embodiments, please refer to Figure 12-14 The plurality of 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. The plurality of 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. 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.

[0218] The first slot segment 611a, the second slot segment 611b and the third slot segment 611c are 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 straight slots extending along a straight track, or can be non-straight slots extending along a non-straight track. If the first slot segment 611a, the second slot segment 611b and the third slot segment 611c all extend along a straight track, 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 in parallel, 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 in parallel.

[0219] The first slot section 611a connects the second slot section 611b and the third slot section 611c. The two ends of the first slot section 611a may be connected to the second slot section 611b and the third slot section 611c respectively, or at least one of the second slot section 611b and the third slot section 611c may be connected to a position deviated from the end of the first slot section 611a, so that at least one of the second slot section 611b and the third slot section 611c is located between the two ends of the first slot section 611a. The position where the second slot section 611b is connected to the first slot section 611a may be located at one end of the second slot section 611b or between the two ends of the second slot section 611b. The position where the third slot section 611c is connected to the first slot section 611a may be located at one end of the third slot section 611c or between the two ends of the third slot section 611c. The first groove section 611a, the second groove section 611b, and the third groove section 611c may jointly define one predetermined pressure relief area 63, or may jointly define multiple predetermined pressure relief areas 63. The first groove section 611a, the second groove section 611b, and the third groove section 611c may form a U-shaped groove, an H-shaped groove, etc. If the first groove section 611a, the second groove section 611b, and the third groove section 611c form a U-shaped groove, the first groove 61 of this structure defines one predetermined pressure relief area 63. If the first groove section 611a, the second groove section 611b, and the third groove section 611c form an H-shaped groove, the first groove 61 of this structure defines two predetermined pressure relief areas 63.

[0220] It should be noted that in the embodiment where the first groove 61 is a multi-stage groove structure, the first groove section 611a, the second groove section 611b and the second groove section 611b are all multi-stage groove structures.

[0221] 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 easier 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.

[0222] In some embodiments, the connection position of 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 of 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.

[0223] 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, that is, the connection position between the second slot segment 611b and the first slot segment 611a is not located at any one of the two ends of the second slot segment 611b, and along the extension direction of the second slot segment 611b, the connection position between the second slot segment 611b and the first slot segment 611a is located between the two ends of the second slot segment 611b. The connection position 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 can be deviated from the midpoint of the second slot segment 611b.

[0224] 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, that is, the connection position between the third slot segment 611c and the first slot segment 611a is not located at any one of the two ends of the third slot segment 611c, and along the extension direction of the third slot segment 611c, the connection position between the third slot segment 611c and the first slot segment 611a is located between the two ends of the third slot segment 611c. The connection position 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 can be deviated from the midpoint of the third slot segment 611c.

[0225] As an example, in Figure 12-14 In the illustrated embodiment, the connection position of the second slot segment 611b and the first slot segment 611a is located at the midpoint of the second slot segment 611b, the connection position of 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 part of the second slot segment 611b, a part 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 part of the second slot segment 611b, another part 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.

[0226] In this embodiment, the connection position of the second slot segment 611b and the first slot segment 611a deviates from the two ends of the second slot segment 611b. During the pressure relief process, after the pressure relief component 6 is cracked at the connection position of the second slot segment 611b and the first slot segment 611a, the crack can spread along the second slot segment 611b to the two ends of the second slot segment 611b, thereby shortening the time for the pressure relief component 6 to be cracked along the second slot segment 611b. The connection position of the third slot segment 611c and the first slot segment 611a deviates from the two ends of the third slot segment 611c. During the pressure relief process, after the pressure relief component 6 is cracked at the connection position of the third slot segment 611c and the first slot segment 611a, the crack can spread along the third slot segment 611c to the two ends of the third slot segment 611c, thereby shortening the time for the pressure relief component 6 to be cracked along the third slot segment 611c. In such a structure, the first groove section 611a of the first groove 61 is located between 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.

[0227] In some embodiments, please refer to Fig.15 and Fig.16 , Fig.15 A partial view of a housing 1 provided for some further embodiments of the present application; Fig.16 for Fig.15 The FF cross-sectional view of the housing 1 is shown. 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. The first slot segment 611a and the second slot segment 611b define at least one predetermined pressure relief area 63 together.

[0228] 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 a linear groove extending along a linear trajectory, or a non-linear groove 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 at their ends 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.

[0229] As an example, in Fig.15 and Fig.16In the illustrated embodiment, the first groove section 611 a is connected to the second groove section 611 b to form a V-shaped structure, the first groove 61 is disposed on the first surface 64 , and the second groove 621 is disposed on the second surface 65 .

[0230] 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 are multi-stage groove structures.

[0231] 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 is simple in structure. The position where the first groove section 611a and the second groove section 611b are connected has a larger stress concentration coefficient, is weaker, and is more likely to crack. When the battery cell 10 thermally runs away, the pressure relief component 6 can quickly crack from the first groove section 611a and the second groove section 611b after cracking from the position where the first groove section 611a and the second groove section 611b are connected, so that the predetermined pressure relief area 63 opens more quickly and releases pressure in time.

[0232] In some embodiments, slot segment 611 extends along a straight trajectory.

[0233] It can be understood that in the embodiment where the first groove 61 includes the first groove section 611a and the second groove section 611b, the first groove section 611a and the second groove section 611b both extend along a straight line track. In the embodiment where the first groove 61 includes the first groove section 611a, the second groove section 611b and the third groove section 611c, the first groove section 611a, the second groove section 611b and the third groove section 611c both extend along a straight line track.

[0234] In this embodiment, the groove segment 611 extends along a straight track, and the groove segment 611 is a straight groove, which can reduce the difficulty of forming the groove segment 611.

[0235] In some embodiments, the slot segment 611 extends along an arc trajectory.

[0236] It can be understood that in the embodiment where the first groove 61 includes the first groove section 611a and the second groove section 611b, the first groove section 611a and the second groove section 611b both extend along an arc track. In the embodiment where the first groove 61 includes the first groove section 611a, the second groove section 611b and the third groove section 611c, the first groove section 611a, the second groove section 611b and the third groove section 611c both extend along an arc track.

[0237] 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 split along the groove section 611 when the battery cell 10 releases pressure, so that the predetermined pressure relief area 63 is opened more quickly.

[0238] In some embodiments, please refer to Fig.17 and Fig.18 , Fig.17 Partial views of the housing 1 provided for some other embodiments of the present application; Fig.18 for Fig.17 The GG cross-sectional view of the housing 1 is shown. The first groove 61 extends along an arc track.

[0239] 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.

[0240] As an example, in Fig.17 and Fig.18 In the illustrated embodiment, the first groove 61 is disposed on the first surface 64 , the second groove 621 is disposed on the second surface 65 , the line connecting the two ends of the first groove 61 is a first line W, and the first groove 61 and the first line W together enclose a predetermined pressure relief area 63 .

[0241] In this embodiment, the first groove 61 extends along an arc track. The first groove 61 of this structure includes only one groove segment 611 , which simplifies the structure of the first groove 61 .

[0242] 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 shape.

[0243] In some embodiments, please refer to Fig.19 , Fig.19 An exploded view of a housing 1 (one end of the housing 11 forms an opening, and the end cover 12 is a 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.

[0244] The first wall portion 13 may be the entire pressure relief component 6, or a part of the first wall portion 13 may be the pressure relief component 6, 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.

[0245] 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 to form an integrated pressure relief structure with higher reliability, eliminating the installation process of the pressure relief component 6 and having better economy.

[0246] 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 .

[0247] If the first groove 61 is a primary groove structure, when the first groove 61 is formed 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 the first groove 61 is formed on the first wall portion 13, the first wall portion 13 can be punched multiple times to punch out a primary groove each time, and the first groove 61 is finally formed after multiple stampings.

[0248] In this embodiment, if the first groove 61 is stamped on the first wall portion 13, the first groove 61 is simply formed, which is beneficial to reducing the production cost of the battery cell 10. If the second groove 621 is stamped on the first wall portion 13, the second groove 621 is simply formed, which is beneficial to reducing the production cost of the battery cell 10.

[0249] In some embodiments, please refer to Fig. 20 , Fig. 20 The exploded view of the housing 1 (one end of the housing 11 forms an opening, and the end cover 12 is the first wall portion 13) provided in some other embodiments of the present application. The pressure relief component 6 is separately provided from the first wall portion 13, and the pressure relief component 6 is installed on the first wall portion 13.

[0250] The pressure relief component 6 and the housing 1 are two separate components, and the pressure relief component 6 is produced separately and then installed on the first wall portion 13. The pressure relief component 6 can be installed on the first wall portion 13 by welding, riveting, bonding, etc. As an example, the first wall portion 13 is provided with a pressure relief hole 131, the pressure relief component 6 covers the pressure relief hole 131, and the pressure relief component 6 is welded to the first wall portion 13.

[0251] 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.

[0252] In some embodiments, please refer to Fig.19 and Fig. 20 The housing 1 includes a shell 11 and an end cover 12 . An opening is formed at least at 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 .

[0253] The shell 11 may have only one opening, for example, the shell 11 has an opening at only one end; the shell 11 may also have multiple openings, for example, the shell 11 has openings at both opposite ends. The number of end caps 12 is the same as the number of openings of the shell 11. It is understandable that if the shell 11 has only one opening, there is one end cap 12, and the end cap 12 is the first wall portion 13; if the shell 11 has two openings, there are two end caps 12, and one end cap 12 may be the first wall portion 13, or both end caps 12 may be the first wall portion 13.

[0254] In the embodiment where the housing 11 is formed with an opening at one end, the positive electrode terminal 3 and the negative electrode terminal 3 may be provided at 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 be electrically connected to the positive electrode terminal 3 and the negative electrode terminal 3, respectively. In the embodiment where the housing 11 is formed with openings at both opposite ends, the positive electrode terminal 3 may be provided at one end cap 12, the negative electrode terminal 3 may be provided at the other end cap 12, and the positive electrode tab 21 and the negative electrode tab 21 may be formed at the opposite ends of the electrode assembly 2, respectively, so as to be electrically connected to the positive electrode terminal 3 and the negative electrode terminal 3, respectively.

[0255] exist Fig.19 In the embodiment shown, one end of the housing 11 forms an opening, and the end cover 12 is a first wall portion 13 ( Fig.19 (not shown), the first wall portion 13 is a pressure relief component 6. Fig. 20 In the illustrated embodiment, an opening is formed at one end of the housing 11 , the end cover 12 is a first wall portion 13 , and the pressure relief component 6 is mounted on the first wall portion 13 .

[0256] 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 installing the pressure relief component 6 is lower.

[0257] In some embodiments, please refer to Fig.21 and Fig. 22 , Fig.21 An exploded view of a housing 1 (an opening is formed at one end of the housing 11, and the housing 11 includes a first wall portion 13) provided in some embodiments of the present application; Fig. 22 An exploded view of a housing 1 (an opening is formed at one end of the housing 11, and the housing 11 includes a first wall portion 13) provided in some other embodiments of the present application. The housing 1 includes a housing 11 and an end cover 12. The housing 11 has an opening formed at least at one end. The end cover 12 corresponds to the opening one by one, and the end cover 12 closes the opening. At least one wall portion in the housing 11 is the first wall portion 13.

[0258] The shell 11 may have only one opening, for example, the shell 11 has an opening formed at only one end; the shell 11 may also have multiple openings, for example, the shell 11 has 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, the end cap 12 is one; if the shell 11 has two openings, the end caps 12 are two. In the embodiment in which the shell 11 has an opening formed at one end, the positive electrode terminal 3 and the negative electrode terminal 3 can be provided on the end cap 12, and the positive electrode ear 21 and the negative electrode ear 21 can 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 the embodiment where openings are formed at both opposite ends of the housing 11, the positive electrode terminal 3 can be provided at one end cap 12, the negative electrode terminal 3 can be provided at the other end cap 12, and the positive electrode tab 21 and the negative electrode tab 21 can be respectively formed at opposite ends of the electrode assembly 2, so that the positive electrode tab 21 is electrically connected to the positive electrode terminal 3 and the negative electrode tab 21 is electrically connected to 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.

[0259] In this embodiment, at least one wall portion in the housing 11 is the first wall portion 13, so that the housing 11 has a pressure relief function. When the battery cell 10 is depressurized, the emissions discharged from the inside of the battery cell 10 are not likely to affect the external components outside the end cap 12, reducing the risk of external components being damaged by emissions. The external components can be a confluence component connected to the electrode terminal 3, a temperature detection component, a voltage detection component, etc. The emissions include, but are not limited to: electrolyte, dissolved or split positive and negative plates, fragments of separators, high-temperature and high-pressure gas generated by the reaction, flames, etc.

[0260] In some embodiments, please refer to Fig.21 and Fig. 22 The shell 11 has an opening at only one end, and the wall portion of the shell 11 that is opposite to the end cover 12 is the first wall portion 13 .

[0261] As an example, the housing 11 is in the shape of a cuboid, and the housing 11 further includes four side walls, which are arranged around the first wall portion 13, and the four side walls and the first wall portion 13 together define a space inside the housing 11. Fig.21 In the illustrated embodiment, an opening is formed at one end of the housing 11, a wall portion of the housing 11 opposite to the end cover 12 is a first wall portion 13, and the pressure relief component 6 is the first wall portion 13. Fig. 22 In the illustrated embodiment, an opening is formed at one end of the shell 11 , and a wall portion of the shell 11 opposite to the end cover 12 is a first wall portion 13 , and the pressure relief component 6 is mounted on the first wall portion 13 .

[0262] In this embodiment, the housing 11 is an open structure at one end, making the structure of the entire battery cell 10 simpler. The first wall 13 is a wall of the housing 11 opposite to the end cover 12, and can achieve directional pressure relief from the bottom of the housing 11.

[0263] In some embodiments, please refer to Fig.23 , Fig.23 The exploded view of the battery cell 10 provided in some other embodiments of the present application. Openings are formed at both opposite ends of the housing 11.

[0264] In the housing 11, one wall portion can be the first wall portion 13, or multiple walls can be the first wall portion 13. The pressure relief component 6 can be integrally formed with the first wall portion 13; the pressure relief component 6 can also be separately provided with the first wall portion 13, or the pressure relief component 6 can also be installed on the first wall portion 13.

[0265] As an example, the housing 11 is in a rectangular parallelepiped shape and includes four wall portions, which are connected end to end in sequence and together define the space inside the housing 11. Among the four wall portions, two opposite wall portions are large-area wall portions, and the other two wall portions are small-area wall portions, and the area of ​​the outer surface of the large-area wall portion is greater than the area of ​​the outer surface of the small-area wall portion, and one or two small-area wall portions in the housing 11 are first wall portions 13.

[0266] In this embodiment, the shell 11 is a structure with openings formed at both opposite ends, and the electrode assembly 2 can be assembled into the shell 11 through any opening, which can reduce the difficulty of assembling the battery cell 10 and improve the assembly quality of the battery cell 10. The shell 11 of this structure can be made longer (openings are formed at both ends of the shell 11 in the length direction), which is conducive to increasing the capacity of the battery cell 10.

[0267] In some embodiments, the material of the pressure relief component 6 includes steel.

[0268] The steel material can be carbon steel, alloy steel, stainless steel, etc.

[0269] It is understandable that in the embodiment where the pressure relief component 6 and the first wall portion 13 are integrally formed, the material of the first wall portion 13 includes steel. If the first wall portion 13 is the end cover 12, the end cover 12 can be made of steel; if the first wall portion 13 is a wall portion in the housing 11, the housing 11 can be made of steel.

[0270] 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.

[0271] In some embodiments, the steel material is carbon steel or stainless steel.

[0272] In some embodiments, the pressure relief component 6 is made of aluminum alloy.

[0273] It is understandable that in the embodiment where the pressure relief component 6 and the first wall portion 13 are integrally formed, the material of the first wall portion 13 includes aluminum alloy. If the first wall portion 13 is the end cover 12, the end cover 12 can be made of aluminum alloy; if the first wall portion 13 is a wall portion in the housing 11, the housing 11 can be made of aluminum alloy.

[0274] 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.

[0275] In some embodiments, the aluminum alloy includes the following components in mass percentage: aluminum ≥ 99.6%, copper ≤ 0.05%, iron ≤ 0.35%, magnesium ≤ 0.03%, manganese ≤ 0.03%, silicon ≤ 0.25%, titanium ≤ 0.03%, vanadium ≤ 0.05%, zinc ≤ 0.05%, and other single elements ≤ 0.03%.

[0276] This aluminum alloy belongs to the third series aluminum, has lower hardness and better forming ability, reduces the difficulty of processing 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.

[0277] In some embodiments, the aluminum alloy includes the following components in mass percentage: aluminum ≥ 96.7%, 0.05% ≤ copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other single element components ≤ 0.05%, and the total composition of other elements ≤ 0.15%.

[0278] 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.

[0279] A battery 100 provided in an embodiment of the present application includes a battery cell 10 provided in any one of the above embodiments.

[0280] An embodiment of the present application provides an electrical device, including a 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.

[0281] Please refer to Figure 3The embodiment of the present application further provides a battery cell 10, which includes a housing 1 and an electrode assembly 2, wherein the electrode assembly 2 has a positive electrode ear 21 and a negative electrode ear 21, and the electrode assembly 2 is accommodated in the housing 1. The housing 1 is in the shape of a rectangular parallelepiped, and includes a shell 11 and an end cover 12, wherein an opening is formed at one end of the shell 11, and the end cover 12 closes the opening, and a positive electrode terminal 3 and a negative electrode terminal 3 are provided on the end cover 12, wherein the positive electrode terminal 3 is electrically connected to the positive electrode ear 21 through a current collecting member 4, and the negative electrode terminal 3 is electrically connected to the negative electrode ear 21 through another current collecting member 4.

[0282] Please refer to Figure 12-14The wall 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. 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 position of the groove section 611a and the second groove section 611b is located at the midpoint of the second groove section 611b, and the connection position of the first groove section 611a and the third groove section 611c is located at the midpoint of the third groove section 611c. The first groove section 611a, the second groove section 611b, and the third groove section 611c jointly define two predetermined pressure relief areas 63. The pressure relief component 6 is configured to be able to split along at least a portion of the first groove 61 when the battery cell 10 is depressurized. The inner surface of the pressure relief component 6 is provided with a groove group 62, and the groove group 62 corresponds to the predetermined pressure relief area 63 one by one. Each groove group 62 includes two second grooves 621, and the two 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, so as to open at least a portion of the predetermined pressure relief area 63. The minimum residual thickness of the first groove 61 is less than the minimum residual thickness of the second groove 621. The predetermined pressure relief zone 63 has an open end 631 and a non-open end 632, and the open end 631 and the non-open end 632 are arranged opposite to 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 in the direction 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, and the projection of the second groove 621 along the thickness direction X of the first wall extends out of the two ends of the first groove 61 at both ends along the extension direction.

[0283] In such a battery cell 10, each slot group 62 includes a plurality of second grooves 621, and the plurality of second grooves 621 are spaced apart along the width direction of the second grooves 621, and the minimum residual thickness of the plurality of second grooves 621 in the slot group 62 gradually decreases in the direction from the non-open end 632 to the open end 631, and the plurality of second grooves 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 can reduce 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.

[0284] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0285] The above embodiments are only used to illustrate the technical solution of the present application and are not used to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: a housing including a first wall portion; a pressure relief component, disposed 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 is pressure-relieved; Wherein, the pressure relief component also includes a groove group, the groove group corresponds to the predetermined pressure relief area one by one, each of the groove groups includes a plurality of second grooves, the plurality of second grooves are arranged at intervals along the width direction of the second groove, and the second groove is 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.

2. The battery cell according to claim 1, characterized in that: The predetermined pressure relief area has an open end and a non-open end, and the open end and the non-open end are arranged opposite to each other along the width direction of the second groove. 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.

3. The battery cell according to claim 2, characterized in that: 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 claim 1, characterized in that: The minimum residual thickness of the first groove is smaller than the minimum residual thickness of the second groove.

5. The battery cell according to claim 4, characterized in that: The minimum residual thickness of the first groove is D1, 0.1 mm≤D1≤0.5 mm.

6. The battery cell according to claim 4, characterized in that: 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 claim 1, characterized in that: The first groove has two ends, a line connecting the two ends is a first line, and the first groove is connected to the first line and together encloses the predetermined pressure relief area; The predetermined pressure relief area has an open end and a non-open end, the first connecting line is located at the non-open end, the open end and the non-open end are arranged opposite to each other 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 open end and the non-open 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, characterized in that: A 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 a projection of the predetermined pressure relief area along the thickness direction of the first wall portion.

9. The battery cell according to claim 8, characterized in that: At least one of the second grooves in the groove group is a first guide groove, a projection of the first guide groove along the thickness direction of the first wall portion and a projection of the predetermined pressure relief area along the thickness direction of the first wall portion do not overlap, the first guide groove and the first groove are spaced apart along the width direction of the first guide groove, and the projection of the first guide groove along the thickness direction of the first wall portion extends out of the two ends of the first groove respectively along the extension direction.

10. The battery cell according to claim 7, characterized in that: 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 open end and the non-open end along the width direction of the second groove.

11. The battery cell according to claim 1, characterized in that: Along the thickness direction of the first wall portion, a projection of the second groove does not overlap with a projection of the first groove.

12. The battery cell according to claim 1, characterized in that: The first groove defines a plurality of the predetermined pressure relief areas.

13. The battery cell according to claim 1, characterized in that: The first wall portion is a rectangular wall portion, and the plurality of second grooves in the groove group are arranged at intervals along a width direction of the first wall portion.

14. The battery cell according to claim 1, characterized in that: The pressure relief component has a first surface and a second surface opposite to 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.

15. The battery cell according to claim 1, characterized in that: The pressure relief component has a first surface and a second surface opposite to each other along the thickness direction of the first wall portion, and both the first groove and the second groove are recessed from the first surface toward the second surface.

16. The battery cell according to claim 14 or 15, characterized in that: The first surface is a surface of the pressure relief member facing the outside of the battery cell, and the second surface is a surface of the pressure relief member facing the inside of the battery cell.

17. The battery cell according to claim 14 or 15, characterized in that: The first groove includes a plurality 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 two adjacent grooves, the primary groove away from the first surface is arranged on the groove bottom surface of the primary groove close to the first surface.

18. The battery cell according to any one of claims 1 to 15, characterized in that: The first groove includes a plurality of groove segments, the plurality of groove segments are connected, and the plurality of groove segments jointly define at least one predetermined pressure relief area.

19. The battery cell according to claim 18, characterized in that: The plurality of slot segments include a first slot segment and a second slot segment, the first slot segment is connected to the second slot segment, and the first slot segment and the second slot segment jointly define at least one predetermined pressure relief area.

20. The battery cell according to claim 18, characterized in that The plurality of slot sections include a first slot section, a second slot section and a third slot section, the second slot section and the third slot section are arranged opposite to each other, the plurality of second grooves in the slot group are located on the same side of the first slot section in the width direction, the first slot section connects the second slot section and the third slot section, and the first slot section, the second slot section and the third slot section jointly define at least one predetermined pressure relief area.

21. The battery cell according to claim 20, characterized in that The connection position between the second slot section and the first slot section deviates from the two ends of the second slot section, and the connection position between the third slot section and the first slot section deviates from the two ends of the third slot section, so that the predetermined pressure relief area is formed on both sides of the first slot section.

22. The battery cell according to claim 18, characterized in that The slot segments extend along straight or arcuate trajectories.

23. The battery cell according to any one of claims 1 to 15, characterized in that: The first groove extends along an arc-shaped trajectory.

24. The battery cell according to any one of claims 1 to 15, characterized in that: The second groove extends along a straight line trajectory.

25. The battery cell according to any one of claims 1 to 15, characterized in that: The pressure relief component is integrally formed with the first wall portion.

26. The battery cell according to claim 25, characterized in that The first groove is stamped and formed on the first wall portion; and / or the second groove is stamped and formed on the first wall portion.

27. The battery cell according to any one of claims 1 to 15, characterized in that: 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 to 15, characterized in that: The housing comprises: A shell having an opening formed at at least one end; An end cover, corresponding to each of the openings, and closing the openings; Wherein, at least one of the end covers is the first wall portion.

29. The battery cell according to any one of claims 1 to 15, characterized in that: The housing comprises: A shell having an opening formed at at least one end; An end cover, corresponding to each of the openings, and closing the openings; Wherein, at least one wall portion in the shell is the first wall portion.

30. The battery cell according to claim 29, characterized in that The opening is formed at only one end of the shell, and the wall portion of the shell opposite to the end cover is the first wall portion.

31. The battery cell according to claim 29, characterized in that The openings are formed at opposite ends of the shell.

32. The battery cell according to any one of claims 1 to 15, characterized in that: The material of the pressure relief component includes steel.

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

34. The battery cell according to any one of claims 1 to 15, characterized in that: The material of the pressure relief component includes aluminum alloy.

35. A battery, characterized in that: Comprising the battery cell according to any one of claims 1-34.

36. An electrical equipment, characterized in that: It comprises a battery cell as described in any one of claims 1 to 34, and the battery cell is used to provide electrical energy to the electrical device.

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