Pressure relief device, battery cell, battery, and electric device

Abstract

The embodiment of the application provides a pressure relief device, a battery monomer, a battery and an electric equipment, and belongs to the technical field of batteries. The pressure relief device comprises a pressure relief part, at least one level of a sink groove and at least one level of a notch groove. The pressure relief part has a first surface and a second surface arranged oppositely in the thickness direction. The at least one level of the sink groove and the at least one level of the notch groove are sequentially arranged on the pressure relief part along the direction from the first surface to the second surface. The groove bottom wall of the sink groove farthest from the first surface has an opening area, the notch groove is arranged along the edge of the opening area, and the opening area is configured to be capable of being opened with the sink groove farthest from the first surface as a boundary. In the forming process, the pressure relief groove and the notch groove can be formed step by step, so that the forming force borne by the pressure relief part is reduced, the risk of cracks of the pressure relief part is reduced, the pressure relief device is not prone to failure due to cracks at the position of the notch groove, and the long-term reliability of the pressure relief device is improved.

Description

[0001] This application is a divisional application of the invention patent application filed on August 31, 2022, with application number 202280009602.6 (PCT / CN2022 / 116299) and entitled "Pressure relief device, battery cell, battery and electrical equipment".

[0002] Among them, the invention patent application filed on August 31, 2022, with application number 202280009602.6 (PCT / CN2022 / 116299) and entitled "Pressure relief device, battery cell, battery and electrical equipment", claims priority to the international patent application PCT / CN2021 / 115766 entitled "Pressure relief device, battery cell, battery and electrical equipment", filed on August 31, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and more specifically, to a pressure relief device, a battery cell, a battery, and an electrical device. Background Technology

[0004] Batteries are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0005] In battery technology, to ensure the safety of individual battery cells, pressure relief devices are typically installed within them. When the internal temperature of the battery cell reaches a threshold, the pressure relief device ruptures at the location of the groove to release the internal pressure. However, with typical pressure relief devices, pressure leakage may still occur even when the internal pressure of the battery cell is within the normal range, resulting in poor long-term reliability. Summary of the Invention

[0006] This application provides a pressure relief device, a battery cell, a battery, and electrical equipment, which can effectively improve the long-term reliability of the pressure relief device.

[0007] In a first aspect, embodiments of this application provide a pressure relief device, including a pressure relief section, at least one primary sink groove, and at least one primary scoring groove; the pressure relief section has a first surface and a second surface disposed opposite to each other in its thickness direction; at least one primary sink groove and at least one primary scoring groove are sequentially disposed on the pressure relief section along the direction from the first surface to the second surface; wherein, the bottom wall of the primary sink groove furthest from the first surface has an opening area, the scoring groove is disposed along the edge of the opening area, and the opening area is configured to be able to be opened with the primary scoring groove furthest from the first surface as the boundary.

[0008] In the above technical solution, at least one level sink groove and at least one level scoring groove are sequentially arranged in the pressure relief part along the direction from the first surface to the second surface. During molding, the pressure relief groove and scoring groove can be formed step by step, thereby reducing the molding force on the pressure relief part, reducing the risk of cracks in the pressure relief part, and making the pressure relief device less likely to fail due to cracks at the location where the scoring groove is set, thus improving the long-term reliability of the pressure relief device.

[0009] In some embodiments, the groove includes a first groove segment, a second groove segment, and a third groove segment. The first and second groove segments are disposed opposite to each other, and both the first and second groove segments intersect with the third groove segment. The first, second, and third groove segments are disposed along the edge of the opening area. In this way, the opening area can be opened with the first, second, and third groove segments as the boundaries, increasing the pressure relief area of ​​the pressure relief section and improving the pressure relief rate of the pressure relief section.

[0010] In some embodiments, the pressure relief section is provided with a fourth groove segment, which is located between the first and second groove segments and intersects with the third groove segment. The stress is more concentrated at the intersection of the fourth and third groove segments, making it more prone to rupture. This causes the pressure relief section to rupture along the third groove segment from the intersection of the third and fourth groove segments during the pressure relief process, and then rupture along the first and second groove segments after the third groove segment ruptures, thereby achieving rapid pressure relief.

[0011] In some embodiments, the fourth groove segment intersects the third groove segment at the intersection point, and in the extending direction of the third groove segment, the distance from the intersection point to the first groove segment is equal to the distance from the intersection point to the second groove segment. This allows the pressure relief section to rupture along the third groove segment at the intersection point of the fourth and third groove segments, and then simultaneously rupture along the first and second groove segments, enabling the opening area to open more quickly.

[0012] In some embodiments, the pressure relief section is provided with a fifth groove segment. In the primary groove furthest from the first surface, the bottom surface of one or both of the first, second, and third groove segments is provided with the fifth groove segment. The pressure relief section is weaker and more prone to breakage at the location of the fifth groove segment. This allows the pressure relief section to break first along the groove segment with the fifth groove segment during pressure relief, and then along the groove segment without the fifth groove segment, improving the timeliness of pressure relief.

[0013] In some embodiments, the first, second, and third slot segments together define at least one opening area. The opening area, defined by the first, second, and third slot segments, can be opened by flipping. After opening, the opening area remains connected to other areas of the pressure relief section, making it less prone to detachment and reducing the risk of splashing after opening.

[0014] In some embodiments, the first, second, and third slot segments define two opening areas, which are located on opposite sides of the third slot segment. During the pressure relief process, the portion of the pressure relief section in the two opening areas can open in a split manner, increasing the pressure relief area and effectively improving the pressure relief rate of the pressure relief section.

[0015] In some embodiments, the groove further includes a sixth groove segment, which is disposed opposite to the third groove segment. The first and second groove segments both intersect with the sixth groove segment, and the first, second, third, and sixth groove segments together define an opening area. Thus, the opening area is a closed region defined by the first, second, third, and sixth groove segments. During the pressure relief process, the pressure relief section can break along the first, second, third, and sixth groove segments, allowing the opening area to open in a detached manner, increasing the pressure relief area and improving the pressure relief rate.

[0016] In some embodiments, the groove is a non-closed groove extending along a non-closed trajectory that is not connected at either end. In this way, the opening area can be opened by flipping, and after the opening area is opened, it is always connected to other areas of the pressure relief part, making it less likely to fall off and reducing the risk of splashing after the opening area is opened.

[0017] In some embodiments, the scoring groove is arc-shaped. The arc-shaped scoring groove has a simple structure and is easy to form. During pressure relief, the pressure relief section can quickly break along the arc-shaped scoring groove, allowing the opening area to open rapidly.

[0018] In some embodiments, the scoring groove is a closed groove extending along a closed trajectory connected at both ends. During the pressure relief process, the pressure relief section can break along the scoring groove, allowing the opening area to open in a disengaged manner, thereby increasing the pressure relief area of ​​the pressure relief section and improving the pressure relief rate of the pressure relief section.

[0019] In some embodiments, the groove is annular. The annular groove has a simple structure and is easy to mold. During pressure relief, the pressure relief section can quickly break along the annular groove, allowing the opening area to open rapidly.

[0020] In some embodiments, the pressure relief section is provided with a primary settling groove, which is disposed on the first surface. The primary settling groove in the pressure relief section simplifies the molding process, improves production efficiency, and reduces production costs.

[0021] In some embodiments, the pressure relief section is provided with a primary scoring groove, which is located on the bottom surface of the settling tank. Providing a primary scoring groove to the pressure relief section simplifies the molding process, improves production efficiency, and reduces production costs.

[0022] In some embodiments, the pressure relief section is provided with multi-level grooves, which are sequentially arranged along the direction from the first surface to the second surface. In two adjacent levels of grooves, the first-level groove furthest from the first surface is located on the bottom surface of the first-level groove closest to the first surface, and the first-level groove closest to the first surface is located on the bottom surface of the groove. The sequential arrangement of multi-level grooves along the direction from the first surface to the second surface reduces the forming depth of each groove, thereby reducing the forming force on the pressure relief section during the forming of each groove and lowering the risk of cracking. During the process of machining multi-level grooves step-by-step along the direction from the first surface to the second surface, the hardness of the residual portion of the pressure relief section in the grooved area increases with each groove machining. This increases the hardness of the residual portion after the multi-level grooves are installed, resulting in better long-term reliability, improved impact resistance, and a reduced probability of breakage from external impacts.

[0023] In some embodiments, the pressure relief section is provided with two or three levels of grooves.

[0024] In some embodiments, the pressure relief section is provided with multiple levels of grooves, which are sequentially arranged along the direction from the first surface to the second surface. In two adjacent levels of grooves, the first-level groove furthest from the first surface is located on the bottom surface of the first-level groove closest to the first surface; wherein, along the thickness direction, the outermost first-level groove is located on the first surface. The multiple levels of grooves in the pressure relief section allow for a relatively shallow forming depth for each level, reducing the forming force on the pressure relief section during the forming of each level and lowering the risk of cracking. When processing the multiple levels of grooves sequentially along the direction from the first surface to the second surface, the hardness of the residual portion in the grooved area of ​​the pressure relief section increases with each level of groove processing, further increasing the hardness of the residual portion in the grooved area of ​​the pressure relief section.

[0025] In some embodiments, the pressure relief section is provided with a primary scoring groove, which is located on the bottom surface of the primary groove furthest from the first surface along the thickness direction. Providing a primary scoring groove in the pressure relief section simplifies the molding process, improves production efficiency, and reduces production costs.

[0026] In some embodiments, the pressure relief section is provided with multi-level grooves, which are sequentially arranged along the direction from the first surface to the second surface. In two adjacent levels of grooves, the first-level groove furthest from the first surface is located on the bottom surface of the first-level groove closest to the first surface, and the first-level groove closest to the first surface is located on the bottom surface of the first-level groove furthest from the first surface. The sequential arrangement of multi-level grooves along the direction from the first surface to the second surface reduces the forming depth of each groove, thereby reducing the forming force on the pressure relief section during the forming of each groove and lowering the risk of cracking. During the process of machining multi-level grooves step-by-step along the direction from the first surface to the second surface, the hardness of the residual portion of the pressure relief section in the grooved area increases with each groove machining. This increased hardness of the residual portion after the multi-level grooves are installed results in better long-term reliability, improved impact resistance, and a reduced probability of breakage from external impacts.

[0027] In some embodiments, the pressure relief section is provided with two or three levels of grooves.

[0028] In some embodiments, the pressure relief section is provided with two or three stages of settling tanks.

[0029] In some embodiments, the pressure relief section is provided with multi-level grooves, which are arranged sequentially along the direction from the first surface to the second surface. In two adjacent levels of grooves, the maximum width of the first-level groove furthest from the first surface is smaller than the minimum width of the first-level groove closest to the first surface. During molding, each level of groove can be formed sequentially along the direction from the first surface to the second surface, which facilitates the forming of each level of groove.

[0030] In some embodiments, the trough is a rectangular or circular trough. The trough has a simple structure, is easy to form, and can provide more clearance for opening the access area.

[0031] In some embodiments, a flange is provided on the first surface, surrounding the recess provided on the first surface. The flange can strengthen the pressure relief section and improve the deformation resistance of the pressure relief area. In addition, the flange facilitates the installation of protective components to protect the opening area.

[0032] In some embodiments, the pressure relief portion partially protrudes from the second surface in a direction away from the first surface to form a protrusion; the protrusion includes a groove bottom wall and a reinforcing portion, the reinforcing portion being connected to the second surface and surrounding the groove bottom wall. The reinforcing portion being connected to the second surface can strengthen the groove bottom wall, improve the deformation resistance of the groove bottom wall, and reduce the risk of stress damage at the location where the groove is provided on the groove bottom wall.

[0033] In some embodiments, the second surface is provided with a groove that surrounds the protrusion. The groove absorbs the energy transmitted from the pressure relief part to the protrusion, and even if the pressure relief part deforms, it is not easily transmitted to the area where the groove is provided.

[0034] In some embodiments, the height by which the protrusion extends beyond the second surface along the thickness direction is H1, and the distance between the first surface and the second surface is H2, satisfying that H1 ≥ H2. This results in a larger height by which the protrusion extends beyond the second surface, enhancing the reinforcing effect of the reinforcing portion on the bottom wall of the groove.

[0035] In some embodiments, the pressure relief part is an end cap, which is used to close the opening of the housing. This gives the end cap a pressure relief function. The pressure relief structure is formed by providing grooves on the end cap, resulting in better stability and good long-term reliability.

[0036] In some embodiments, the first surface is the surface of the end cap that faces away from the housing.

[0037] In some embodiments, the pressure relief device is a housing with an internal receiving space. The housing includes multiple walls that collectively define the receiving space, which is used to receive the electrode assembly. At least one wall is a pressure relief portion. This pressure relief device has both the function of receiving the electrode assembly and the function of pressure relief.

[0038] In some embodiments, the housing includes a peripheral wall and a bottom wall, the peripheral wall surrounding the edge of the bottom wall, the peripheral wall and the bottom wall together defining an accommodating space, an opening being formed at the opposite end of the peripheral wall and the bottom wall, and the bottom wall serving as a pressure relief portion. This allows the bottom wall of the pressure relief device to have a pressure relief function, facilitating the release of pressure inside the accommodating space.

[0039] In some embodiments, the first surface is the outer surface of the wall portion. This allows for the formation of countersunk grooves and scoring grooves on the outer side of the wall portion, facilitating the fabrication of countersunk grooves and scoring grooves on the bottom wall.

[0040] Secondly, embodiments of this application provide a battery cell including the pressure relief device provided in any of the embodiments of the first aspect above.

[0041] Thirdly, embodiments of this application provide a battery, including the battery cell provided in any of the embodiments of the second aspect above.

[0042] Fourthly, embodiments of this application provide an electrical device including the battery provided in any of the embodiments of the third aspect above. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments; Figure 2 This application provides schematic diagrams of the battery structure for some embodiments. Figure 3 Exploded views of a single battery cell provided in some embodiments of this application; Figure 4 Axonometric view of a pressure relief device provided in some embodiments of this application; Figure 5 for Figure 4 Top view of the pressure relief device shown; Figure 6 for Figure 5 A cross-sectional view of the pressure relief device shown in Figure AA; Figure 7 for Figure 5 A partial enlarged view of point B of the pressure relief device shown; Figure 8 A partial enlarged view of the pressure relief device provided in some embodiments of this application; Figure 9 A partial enlarged view of the pressure relief device provided in other embodiments of this application; Figure 10 for Figure 6 A partial enlarged view of point C of the pressure relief device shown; Figure 11 A partial enlarged view of a pressure relief device provided in some embodiments of this application; Figure 12 A partial enlarged view of the pressure relief device provided in some embodiments of this application; Figure 13 A partial enlarged view of the pressure relief device provided in other embodiments of this application; Figure 14 for Figure 7 The pressure relief device shown is a DD cross-sectional view. Figure 15 Top view of a pressure relief device provided in other embodiments of this application; Figure 16 for Figure 15 A partial enlarged view of point E of the pressure relief device shown; Figure 17 for Figure 16 The pressure relief device shown is a cross-sectional view (FF) of the device. Figure 18 Isometric view of a pressure relief device provided in other embodiments of this application; Figure 19 for Figure 18 A partial enlarged view of point G of the pressure relief device shown; Figure 20 for Figure 18 A partial cross-sectional view of the pressure relief device shown; Figure 21 Axonometric view of a pressure relief device provided in some further embodiments of this application; Figure 22 for Figure 21 A partial enlarged view of point H of the pressure relief device shown; Figure 23 for Figure 22 A partial cross-sectional view of the pressure relief device shown; Figure 24 Axonometric view of a pressure relief device provided in some embodiments of this application; Figure 25 for Figure 24 A partial enlarged view of point I of the pressure relief device shown.

[0045] Icons: 1-Housing; 2-Electrode assembly; 21-Positive electrode tab; 22-Negative electrode tab; 3-End cap; 31-Positive electrode terminal; 32-Negative electrode terminal; 4-Current collector; 5-Insulator; 6-Pressure relief device; 61-Pressure relief section; 611-First surface; 6111-Flange; 612-Second surface; 6121-Protrusion; 6121a-Reinforcing section; 6122-Groove; 613-Groove bottom wall; 6131-Opening area; 62-Sinking groove; 63-Scratched groove; 631-First groove segment; 632-Second groove segment; 633-Third groove segment; 634-Sixth groove segment; 64-Fourth groove segment; 65-Fifth groove segment; 66-Notch groove; 67-Peripheral wall; 68-Bottom wall; 10-Battery cell; 20-Box; 201-First part; 202-Second part; 100-Battery; 200-Controller; 300-Motor; 1000-Vehicle; Z-Thickness direction. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0048] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0049] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0050] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0051] In the embodiments of this application, the same reference numerals denote 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 this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0052] In this application, "multiple" means two or more (including two).

[0053] In this application, the battery cell may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application are not limited to these. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited to these. Battery cells are generally divided into three types according to their packaging method: cylindrical battery cells, square battery cells, and pouch battery cells, and the embodiments of this application are not limited to these.

[0054] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack. A battery generally includes a housing for encapsulating one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0055] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the uncoated positive current collector protrudes beyond the coated one, serving as the positive electrode tab. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the uncoated negative current collector protrudes beyond the coated one, serving as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon, etc. To ensure that a large current can pass through without melting, there are multiple positive electrode tabs stacked together, and there are multiple negative electrode tabs stacked together. The separator can be made of PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly can be a wound structure or a stacked structure, and the embodiments of this application are not limited to these.

[0056] The development of battery technology must take into account multiple design factors, such as energy density, cycle life, discharge capacity, charge / discharge rate and other performance parameters. In addition, battery safety also needs to be considered.

[0057] The pressure relief device on a battery cell has a significant impact on battery safety. For example, in the event of a short circuit or overcharging, thermal runaway may occur inside the battery cell, causing a sudden increase in pressure or temperature. In such cases, the pressure relief mechanism can be activated to release the internal pressure and temperature to the outside, preventing the battery cell from exploding or catching fire.

[0058] The inventors discovered that in typical battery cells, pressure relief devices can cause pressure leakage even when the internal pressure of the cell is within the normal range, leading to cell failure. Further research revealed that pressure relief devices typically have grooves in the relief section. To ensure proper pressure relief when the internal pressure or temperature of the battery cell reaches a threshold, the grooves need to be machined quite deep. After the grooves are formed, cracks are prone to appear, resulting in pressure leakage even when the internal pressure of the battery cell is within the normal range (below the threshold).

[0059] In view of this, the present application provides a pressure relief device, wherein at least one level of sink groove and at least one level of scoring groove are arranged sequentially on the pressure relief part of the pressure relief device from the first surface to the second surface. The bottom wall of the sink groove furthest from the first surface has an opening area, and the scoring groove is arranged along the edge of the opening area. The opening area is configured to be able to be opened with the scoring groove furthest from the first surface as the boundary.

[0060] In such a pressure relief device, at least one level of sink groove and at least one level of scoring groove are sequentially arranged in the pressure relief part along the direction from the first surface to the second surface. During molding, the pressure relief groove and scoring groove can be formed step by step, thereby reducing the molding force on the pressure relief part, reducing the risk of cracks in the pressure relief part, and making the pressure relief device less likely to fail due to cracks at the location where the scoring groove is set, thus improving the long-term reliability of the pressure relief device.

[0061] The pressure relief device described in the embodiments of this application is applicable to batteries and electrical equipment that uses batteries.

[0062] Electrical equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical equipment.

[0063] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0064] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. A battery 100 is disposed inside the vehicle 1000, and the battery 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000.

[0065] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0066] In some embodiments of this application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0067] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of a battery 100 provided in some embodiments of this application. The battery 100 includes a battery cell 10 and a housing 20, the housing 20 being used to house the battery cell 10.

[0068] The housing 20 is a component that houses the battery cell 10, providing a storage space for the battery cell 10. The housing 20 can have various structures. In some embodiments, the housing 20 may include a first portion 201 and a second portion 202, which overlap each other to define a storage space for accommodating the battery cell 10. The first portion 201 and the second portion 202 can have various shapes, such as a cuboid or a cylinder. The first portion 201 may be a hollow structure open on one side, and the second portion 202 may also be a hollow structure open on one side, with the open side of the second portion 202 overlapping the open side of the first portion 201, thus forming a housing 20 with a storage space. Alternatively, the first portion 201 may be a hollow structure open on one side, and the second portion 202 may be a plate-like structure, with the second portion 202 overlapping the open side of the first portion 201, thus forming a housing 20 with a storage space. The first part 201 and the second part 202 can be sealed by a sealing element, which can be a sealing ring, sealant, etc.

[0069] In battery 100, there can be one or more battery cells 10. If there are multiple battery cells 10, they can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 10 are connected in both series and parallel. Alternatively, multiple battery cells 10 can be first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed manner to form a whole, which is then housed within the housing 20. Another option is that all battery cells 10 can be directly connected in series, parallel, or in a mixed manner, and then the whole consisting of all battery cells 10 is housed within the housing 20.

[0070] In some embodiments, the battery 100 may further include a busbar component, through which multiple battery cells 10 can be electrically connected to each other to achieve series, parallel, or mixed connection of multiple battery cells 10. The busbar component may be a metallic conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0071] Please refer to Figure 3 , Figure 3 This is an exploded view of a battery cell 10 provided in some embodiments of this application. The battery cell 10 includes a housing 1, an electrode assembly 2, an end cap 3, an insulating component 5, and a pressure relief device 6. Figure 3 (Not shown).

[0072] The housing 1 is a component used to house the electrode assembly 2. The housing 1 can be a hollow structure with an opening at one end. The housing 1 can be of various shapes, such as a cylinder or a cuboid. The housing 1 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy.

[0073] The electrode assembly 2 inside the housing 1 can be one or more. For example, as shown in the figure, there are multiple electrode assemblies 2, which are stacked and arranged inside the housing 1.

[0074] Electrode assembly 2 is the component in the battery cell 10 where electrochemical reactions occur. Electrode assembly 2 may include a positive electrode, a negative electrode, and a separator. Electrode assembly 2 can be a wound structure formed by winding the positive electrode, separator, and negative electrode, or a stacked structure formed by arranging the positive electrode, separator, and negative electrode in layers.

[0075] The positive electrode may include a positive current collector and positive active material layers coated on opposite sides of the positive current collector. The negative electrode may include a negative current collector and negative active material layers coated on opposite sides of the negative current collector. The electrode assembly 2 has a positive electrode tab 21 and a negative electrode tab 22. The positive electrode tab 21 may be a portion of the positive electrode that is not coated with a positive active material layer, and the negative electrode tab 22 may be a portion of the negative electrode that is not coated with a negative active material layer.

[0076] End cap 3 is a component that closes onto the opening of housing 1 to isolate the internal environment of battery cell 10 from the external environment. End cap 3 closes onto the opening of housing 1, and end cap 3 and housing 1 together define a sealed space for accommodating electrode assembly 2, electrolyte, and other components. The shape of end cap 3 can be adapted to the shape of housing 1. For example, if housing 1 is a cuboid structure, end cap 3 can be a rectangular plate structure adapted to housing 1; or if housing 1 is a cylindrical structure, end cap 3 can be a circular plate structure adapted to housing 1. The material of end cap 3 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of end cap 3 can be the same as or different from the material of housing 1.

[0077] Electrode terminals can be provided on the end cap 3. These terminals are used to electrically connect to the electrode assembly 2 to output electrical energy from the battery cell 10. The electrode terminals may include a positive electrode terminal 31 and a negative electrode terminal 32. The positive electrode terminal 31 is used to electrically connect to the positive electrode tab 21, and the negative electrode terminal 32 is used to electrically connect to the negative electrode tab 22. The positive electrode terminal 31 and the positive electrode tab 21 can be directly connected or indirectly connected, as can the negative electrode terminal 32 and the negative electrode tab 22. For example, the positive electrode terminal 31 is electrically connected to the positive electrode tab 21 through a current collector 4, and the negative electrode terminal 32 is electrically connected to the negative electrode tab 22 through another current collector 4.

[0078] The insulating component 5 separates the housing 1 from the electrode assembly 2, achieving insulation between the housing 1 and the electrode assembly 2. The insulating component 5 is made of an insulating material, such as plastic or rubber. For example, the insulating component 5 circumferentially covers the outer periphery of the electrode assembly 2. It is understood that when there are multiple electrode assemblies 2, the insulating component 5 circumferentially covers the entire outer periphery of all the electrode assemblies 2.

[0079] The pressure relief device 6 is a component that releases pressure inside the battery cell 10. When the pressure or temperature inside the battery cell 10 reaches a threshold, the pressure is released through the pressure relief device 6. The pressure relief device 6 can be a component installed on the end cap 3, or the housing 1 can be used as the pressure relief device 6, or the end cap 3 can be used as the pressure relief device 6. The specific structure of the pressure relief device 6 will be described in detail below with reference to the accompanying drawings.

[0080] Please refer to Figures 4-6 , Figure 4 This is an isometric view of the pressure relief device 6 provided in some embodiments of this application. Figure 5 for Figure 4 The pressure relief device 6 shown is a top view. Figure 6 for Figure 5The pressure relief device 6 shown in the AA cross-sectional view illustrates that this application provides a pressure relief device 6, including a pressure relief section 61, at least one primary sink 62, and at least one primary scoring groove 63. The pressure relief section 61 has a first surface 611 and a second surface 612 disposed opposite to each other in its thickness direction Z. The at least one primary sink 62 and the at least one primary scoring groove 63 are sequentially disposed on the pressure relief section 61 along the direction from the first surface 611 to the second surface 612. The bottom wall 613 of the primary sink 62 furthest from the first surface 611 has an opening area 6131, and the scoring groove 63 is disposed along the edge of the opening area 6131. ​​The opening area 6131 is configured to be openable with the primary scoring groove 63 furthest from the first surface 611 as its boundary.

[0081] The pressure relief part 61 can be a component installed on the end cover 3. For example, the pressure relief part 61 can be an explosion-proof sheet installed on the end cover 3. The pressure relief part 61 can also be the end cover 3 as a whole. The pressure relief part 61 can be part of the housing 1. For example, the pressure relief part 61 can be a wall part or part of a wall part of the housing 1.

[0082] The first surface 611 and the second surface 612 of the pressure relief part 61 are two opposing surfaces of the pressure relief part 61 in its thickness direction Z, and the distance between the first surface 611 and the second surface 612 is the thickness of the pressure relief part 61. Taking the pressure relief part 61 as an end cap 3 as an example, the first surface 611 can be the outer surface of the end cap 3, facing the outside of the battery cell 10, and the second surface 612 can be the inner surface of the end cap 3, facing the inside of the battery cell 10.

[0083] The pressure relief section 61 can be provided with a single-stage sinker 62 or multiple-stage sinkers 62. If multiple-stage sinkers 62 are provided on the pressure relief section 61, the multiple-stage sinkers 62 are sequentially arranged on the pressure relief section 61 along the direction from the first surface 611 to the second surface 612, and the contour of the bottom surface of each stage sinker 62 decreases progressively. The sinkers 62 can be of various shapes, such as rectangular or circular. The sinkers 62 on the pressure relief section 61 can be formed by various methods, such as stamping or milling.

[0084] The pressure relief section 61 can be provided with a single-level groove 63 or multiple-level grooves 63. If multiple-level grooves 63 are provided on the pressure relief section 61, the multiple-level grooves 63 are sequentially arranged on the pressure relief section 61 along the direction from the first surface 611 to the second surface 612. The grooves 63 can be grooves of various shapes, such as arc-shaped, H-shaped, U-shaped, annular, etc. The grooves 63 on the pressure relief section 61 can be formed by various methods, such as stamping, milling, etc. Taking the forming of at least one level countersunk groove 62 and at least one level groove 63 by stamping as an example, at least one level countersunk groove 62 and at least one level groove 63 can be sequentially stamped on the pressure relief section 61 along the direction from the first surface 611 to the second surface 612. For example, Figure 6 As shown, the pressure relief part 61 is provided with a first-level groove 63 and a first-level sink groove 62, and both the groove 63 and the sink groove 62 are stamped. The sink groove 62 can be stamped on the first surface 611 first, and then the groove 63 can be stamped on the bottom surface of the sink groove 62.

[0085] At least one level of recessed groove 62 and at least one level of scoring groove 63 are sequentially provided with pressure relief portions 61 along the direction from the first surface 611 to the second surface 612. During molding, all recessed grooves 62 can be formed on the pressure relief portions 61 first, and then all scoring grooves 63 can be formed. Understandably, the first level scoring groove 63 closest to the first surface 611 is located on the bottom surface of the first level recessed groove 62 furthest from the first surface 611. If only one level of scoring groove 63 is provided in the pressure relief portion 61, this first level scoring groove 63 is both the first level scoring groove 63 closest to the first surface 611 and the first level scoring groove 63 furthest from the first surface 611; if only one level of recessed groove 62 is provided in the pressure relief portion 61, this first level recessed groove 62 is both the first level recessed groove 62 closest to the first surface 611 and the first level recessed groove 62 furthest from the first surface 611.

[0086] The bottom wall 613 of the primary sink 62 furthest from the first surface 611 is the portion of the pressure relief part 61 below the bottom surface of the primary sink 62 furthest from the first surface 611. After the pressure relief part 61 forms the primary sink 62 furthest from the first surface 611, the remaining portion of the area where the pressure relief part 61 provides the primary sink 62 is the bottom wall 613 of the primary sink 62 furthest from the first surface 611. Figure 6 As shown, taking the pressure relief section 61 with a first-level settling tank 62 as an example, the part of the pressure relief section 61 below the bottom surface of the settling tank 62 is the bottom wall 613 of the first-level settling tank 62 that is furthest from the first surface 611.

[0087] The opening area 6131 is the pressure relief area of ​​the pressure relief section 61. For the battery cell 10, when the internal pressure or temperature of the battery cell 10 reaches a threshold, the opening area 6131 will open with the first-level groove 63 furthest from the first surface 611 as the boundary to achieve pressure relief. The opening area 6131 is formed on the bottom wall 613 of the first-level groove 62 furthest from the first surface 611. The opening area 6131 is the part of the bottom wall 613 of the first-level groove 62 furthest from the first surface 611 that can open with the first-level groove 63 furthest from the first surface 611 as the boundary during pressure relief. The opening area 6131 can be opened by detachment or by flipping. The groove 63 is provided along the edge of the opening area 6131. ​​It can be understood that if the pressure relief section 61 is provided with multiple levels of grooves 63, the shape of each level of groove 63 is basically the same and they are all provided along the edge of the opening area 6131.

[0088] In this embodiment, at least one level sink groove 62 and at least one level scoring groove 63 are sequentially disposed on the pressure relief part 61 along the direction from the first surface 611 to the second surface 612. During molding, the pressure relief groove and scoring groove 63 can be formed step by step, thereby reducing the molding force on the pressure relief part 61, reducing the risk of cracks in the pressure relief part 61, and making the pressure relief device 6 less prone to failure due to cracks at the location where the scoring groove 63 is disposed, thus improving the long-term reliability of the pressure relief device 6.

[0089] When forming the recessed groove 62 and the scoring groove 63 on the pressure relief section 61, the recessed groove 62 can be formed first, followed by the scoring groove 63. This results in a relatively shallow forming depth for each groove, reducing the forming force on the pressure relief section 61. This reduces the risk of cracking in the pressure relief section 61 and improves the flatness of the first surface 611. After forming the recessed groove 62 on the pressure relief section 61, the entire pressure relief section 61 in the area where the recessed groove 62 is set is thinned, increasing the hardness of the remaining portion in that area. This results in increased hardness of the remaining portion of the pressure relief section 61 in the scoring groove 63 area after the final scoring groove 63 is formed, leading to better long-term reliability, improved impact resistance, and a reduced probability of breakage from external impacts.

[0090] Because the groove 63 is provided along the edge of the opening area 6131, and the opening area 6131 can be opened with the first-level groove 63 furthest from the first surface 611 as the boundary, the pressure relief area of ​​the pressure relief section 61 is increased, and the pressure relief rate of the pressure relief section 61 is improved. In addition, since the bottom wall 613 of the first-level sink 62 furthest from the first surface 611 has the opening area 6131, the sink 62 can provide clearance space for the opening area 6131 to open, so that even if the first surface 611 is blocked by an obstacle, the opening area 6131 can still open to relieve pressure.

[0091] In some embodiments, please refer to Figure 7 , Figure 7 for Figure 5 The enlarged view of part B of the pressure relief device 6 is shown. The groove 63 includes a first groove segment 631, a second groove segment 632 and a third groove segment 633. The first groove segment 631 and the second groove segment 632 are arranged opposite to each other. The first groove segment 631 and the second groove segment 632 intersect with the third groove segment 633. The first groove segment 631, the second groove segment 632 and the third groove segment 633 are arranged along the edge of the opening area 6131.

[0092] The first groove segment 631, the second groove segment 632, and the third groove segment 633 can all be straight grooves. The first groove segment 631 can be parallel to the second groove segment 632, and the first groove segment 631 and the second groove segment 632 can be perpendicular to the third groove segment 633. The intersection of the first groove segment 631 and the third groove segment 633 can be located at one end of the third groove segment 633 or at a position offset from one end of the third groove segment 633, such that one end of the third groove segment 633 extends beyond the first groove segment 631 along the extension direction of the third groove segment 633. The intersection of the second groove segment 632 and the third groove segment 633 can be located at the other end of the third groove segment 633 or at a position offset from the other end of the third groove segment 633, such that the other end of the third groove segment 633 extends beyond the second groove segment 632 along the extension direction of the third groove segment 633. The third groove segment 633 can be located at the end of the first groove segment 631 and the second groove segment 632. For example, the first groove segment 631, the third groove segment 633, and the second groove segment 632 are connected sequentially to form a U-shape. The third groove segment 633 can also be located in the middle of the first groove segment 631 and the second groove segment 632. Figure 7 As shown, the first groove segment 631, the second groove segment 632, and the third groove segment 633 form an H-shape.

[0093] It should be noted that in the embodiment where the pressure relief section 61 is provided with multiple levels of grooves 63, it is understood that in two adjacent levels of grooves 63, the first groove segment 631 of the first level groove 63 away from the first surface 611 is disposed on the bottom surface of the first groove segment 631 of the first level groove 63 close to the first surface 611, and the two adjacent levels of the first groove segment 631 extend in the same direction; the second groove segment 632 of the first level groove 63 away from the first surface 611 is disposed on the bottom surface of the second groove segment 632 of the first level groove 63 close to the first surface 611, and the two adjacent levels of the second groove segment 632 extend in the same direction; the third groove segment 633 of the first level groove 63 away from the first surface 611 is disposed on the bottom surface of the third groove segment 633 of the first level groove 63 close to the first surface 611, and the two adjacent levels of the third groove segment 633 extend in the same direction.

[0094] In this embodiment, the opening area can be opened with the first slot segment, the second slot segment, and the third slot segment as the boundary, which increases the pressure relief area of ​​the pressure relief section and improves the pressure relief rate of the pressure relief section.

[0095] In some embodiments, please refer to Figure 8 , Figure 8 This is a partial enlarged view of the pressure relief device 6 provided in some embodiments of this application. The pressure relief section 61 is provided with a fourth groove segment 64, which is located between the first groove segment 631 and the second groove segment 632, and intersects with the third groove segment 633.

[0096] The fourth groove segment 64 can be a straight groove. The fourth groove segment 64 is correspondingly provided with the scoring groove 63. If the pressure relief part 61 is provided with a single-level scoring groove 63, then the pressure relief part 61 is correspondingly provided with a single-level fourth groove segment 64; if the pressure relief part 61 is provided with multiple levels of scoring grooves 63, then the pressure relief part 61 is correspondingly provided with multiple levels of fourth groove segments 64, and the single-level scoring groove 63 is correspondingly provided with a single-level fourth groove segment 64. Along the direction from the first surface 611 to the second surface 612, in two adjacent levels of fourth groove segments 64, the first-level fourth groove segment 64 furthest from the first surface 611 is located on the bottom surface of the first-level fourth groove segment 64 closest to the first surface 611, so that the width of the multiple levels of fourth groove segments 64 gradually decreases. The fourth slot segment 64 can be parallel to the first slot segment 631 and the second slot segment 632, and perpendicular to the third slot segment 633.

[0097] For example, the fourth slot segment 64 intersects the third slot segment 633 at the midpoint of the fourth slot segment 64 and the midpoint of the third slot segment 633. The length of the fourth slot segment 64 is less than the length of the first slot segment 631 and the second slot segment 632.

[0098] The stress is more concentrated at the intersection of the fourth groove segment 64 and the third groove segment 633, making it easier to break. This causes the pressure relief section 61 to break along the third groove segment 633 at the intersection of the third groove segment 633 and the fourth groove segment 64 during the pressure relief process, and then break along the first groove segment 631 and the second groove segment 632 after the third groove segment 633 breaks, so as to achieve rapid pressure relief.

[0099] In this embodiment, the opening area 6131 can be opened with the first slot segment 631, the second slot segment 632 and the third slot segment 633 as the boundary, which increases the pressure relief area of ​​the pressure relief part 61 and improves the pressure relief rate of the pressure relief part 61.

[0100] In some embodiments, the fourth slot segment 64 intersects the third slot segment 633 at an intersection position, and in the extending direction of the third slot segment 633, the distance from the intersection position to the first slot segment 631 is equal to the distance from the intersection position to the second slot segment 632.

[0101] In the extending direction of the third slot segment 633, the distance from the intersection point to the first slot segment 631 is the length of the portion of the third slot segment 633 between the fourth slot segment 64 and the first slot segment 631. Similarly, in the extending direction of the third slot segment 633, the distance from the intersection point to the second slot segment 632 is the length of the portion of the third slot segment 633 between the fourth slot segment 64 and the second slot segment 632. Taking an example where the two ends of the third slot segment 633 are connected to the first slot segment 631 and the second slot segment 632 respectively, and the fourth slot segment 64 is positioned in the middle of the third slot segment 633, then the distance from the intersection point to the first slot segment 631 is equal to the distance from the intersection point to the second slot segment 632.

[0102] In this embodiment, since the distance from the intersection of the fourth groove segment 64 and the third groove segment 633 to the first groove segment 631 is equal to the distance from the intersection of the fourth groove segment 64 and the third groove segment 633 to the second groove segment 632, the pressure relief part 61 can break along the third groove segment 633 at the intersection of the fourth groove segment 64 and the third groove segment 633, and then break along the first groove segment 631 and the second groove segment 632 simultaneously, so that the opening area 6131 can open more quickly.

[0103] Please refer to Figure 9 , Figure 9 The following is a partial enlarged view of the pressure relief device 6 provided in some other embodiments of this application. The pressure relief part 61 is provided with a fifth groove segment 65. In the first-level groove 63 furthest from the first surface 611, the bottom surface of one or both of the first groove segment 631, the second groove segment 632 and the third groove segment 633 is provided with the fifth groove segment 65.

[0104] Understandably, the fifth groove segment 65 is disposed on the bottom surface of the first-level groove 63 furthest from the first surface 611. For example, in... Figure 9 In the middle, a fifth groove segment 65 is provided on the bottom surface of the third groove segment 633 in the first-level groove 63 that is furthest from the first surface 611.

[0105] The pressure relief section 61 is weaker and more prone to breakage at the location where the fifth groove 65 is provided. This causes the pressure relief section 61 to break first along the groove where the fifth groove 65 is provided when pressure is released, and then along the groove where the fifth groove 65 is not provided, thus improving the timeliness of pressure relief.

[0106] In some embodiments, please continue to refer to Figures 7-9 The first slot segment 631, the second slot segment 632 and the third slot segment 633 together define at least one open area 6131.

[0107] The opening area 6131 is defined by the first groove segment 631, the second groove segment 632, and the third groove segment 633. The groove 63 is not a closed structure. The opening area 6131 defined by the first groove segment 631, the second groove segment 632, and the third groove segment 633 can be one or two. For example, if the first groove segment 631, the second groove segment 632, and the third groove segment 633 form a U-shaped structure, then there is one opening area 6131; or, if the first groove segment 631, the second groove segment 632, and the third groove segment 633 form an H-shaped structure, then there are two opening areas 6131.

[0108] In this embodiment, the opening area 6131 is defined by the first groove segment 631, the second groove segment 632 and the third groove segment 633. The opening area 6131 can be opened by flipping. After the opening area 6131 is opened, it is always connected to other areas of the pressure relief part 61, and it is not easy to fall off, thus reducing the risk of splashing after the opening area 6131 is opened.

[0109] In some embodiments, please continue to refer to Figures 7-9 The first slot segment 631, the second slot segment 632 and the third slot segment 633 define two opening areas 6131, which are located on both sides of the third slot segment 633.

[0110] The first slot segment 631, the second slot segment 632, and the third slot segment 633 together define two open areas 6131, which can form an H-shaped structure. The third slot segment 633 intersects with the first slot segment 631 at the midpoint of the first slot segment 631, and the third slot segment 633 intersects with the second slot segment 632 at the midpoint of the second slot segment 632.

[0111] The two opening areas 6131 are located on both sides of the third groove segment 633, so that the two opening areas 6131 are separated by the third groove segment 633. After the pressure relief part 61 breaks at the position of the third groove segment 633, the two opening areas 6131 will open in a split manner along the first groove segment 631 and the second groove segment 632 to achieve pressure relief, increase the pressure relief area, and effectively improve the pressure relief rate of the pressure relief part 61.

[0112] In some embodiments, please refer to Figures 7-10 , Figure 10 for Figure 6 The enlarged view of part C of the pressure relief device 6 shown. The opening area 6131 is provided with a notch 66, and in the extension direction of the first groove segment 631, the notch 66 is at a distance from the third groove segment 633.

[0113] The notch 66 can be located entirely in the opening area 6131 or partially in the opening area 6131.

[0114] For example, the notch 66 is provided on the surface of the bottom wall 613 of the primary sink 62 furthest from the first surface 611, away from the first surface 611.

[0115] The notch 66 can extend along the extension direction of the third groove segment 633, so that the notch 66 is parallel to the third groove segment 633.

[0116] In an embodiment where the first slot segment 631, the second slot segment 632, and the third slot segment 633 jointly define an opening area 6131, a corresponding notch slot 66 can be provided. For example... Figure 9 As shown, in the embodiment where the first slot segment 631, the second slot segment 632, and the third slot segment 633 jointly define two opening areas 6131, two notch slots 66 can be provided accordingly, and one notch slot 66 can be provided for each opening area 6131.

[0117] In this embodiment, the notch 66 is at a distance from the third groove 633 in the extending direction of the first groove 631, and the notch 66 is disposed in the opening area 6131, so that during the pressure relief process, a part of the pressure relief part 61 located in the opening area 6131 can be rotated around the position of the pressure relief part 61 located in the notch 66, making it easier to open the pressure relief part 61.

[0118] In some embodiments, please refer to Figure 11 , Figure 11 This is a partial enlarged view of the pressure relief device 6 provided in some embodiments of this application. The groove 63 further includes a sixth groove segment 634, which is disposed opposite to the third groove segment 633. The first groove segment 631 and the second groove segment 632 both intersect with the sixth groove segment 634. The first groove segment 631, the second groove segment 632, the third groove segment 633 and the sixth groove segment 634 together define the opening area 6131.

[0119] The sixth slot segment 634 can be arranged parallel to the third slot segment 633. The first slot segment 631, the third slot segment 633, the second slot segment 632, and the sixth slot segment 634 can be connected end-to-end to form a closed structure. Of course, the two ends of the first slot segment 631 can extend beyond the third slot segment 633 and the sixth slot segment 634 respectively; the two ends of the second slot segment 632 can extend beyond the third slot segment 633 and the sixth slot segment 634 respectively; the two ends of the third slot segment 633 can extend beyond the first slot segment 631 and the second slot segment 632 respectively; and the two ends of the sixth slot segment 634 can extend beyond the first slot segment 631 and the second slot segment 632 respectively. For example, in... Figure 11 In the middle, the first slot segment 631, the third slot segment 633, the second slot segment 632 and the sixth slot segment 634 are connected end to end to form a rectangular structure.

[0120] It should be noted that in this embodiment, the pressure relief section 61 may or may not have a fourth groove section 64.

[0121] The opening area 6131 is a closed area defined by the first groove segment 631, the second groove segment 632, the third groove segment 633, and the sixth groove segment 634. During the pressure relief process, the pressure relief part 61 can break along the first groove segment 631, the second groove segment 632, the third groove segment 633, and the sixth groove segment 634, so that the opening area 6131 can be opened in a detached manner, thereby increasing the pressure relief area of ​​the pressure relief part 61 and improving the pressure relief rate of the pressure relief part 61.

[0122] In some embodiments, please refer to Figure 12 , Figure 12 This is a partial enlarged view of the pressure relief device 6 provided in some embodiments of this application. The groove 63 is a non-closed groove extending along a non-closed trajectory that is not connected at either end.

[0123] In this embodiment, the shape of the groove 63 can be various, such as arc shape, U shape, etc.

[0124] In this embodiment, the groove 63 is a non-closed groove that extends along a non-closed trajectory that is not connected at the beginning and end. The opening area 6131 can be opened by flipping. After the opening area 6131 is opened, it is always connected to other areas of the pressure relief part 61, making it difficult to fall off and reducing the risk of splashing after the opening area 6131 is opened.

[0125] In some embodiments, please continue to refer to Figure 12 The groove 63 is arc-shaped. The arc-shaped groove 63 has a simple structure and is easy to form. During pressure relief, the pressure relief part 61 can quickly break along the arc-shaped groove 63, so that the opening area 6131 can be opened quickly.

[0126] In some embodiments, please refer to Figure 13 , Figure 13 This is a partial enlarged view of the pressure relief device 6 provided in other embodiments of this application. The groove 63 is a closed groove extending along a closed trajectory connecting the two ends.

[0127] In this embodiment, the shape of the groove 63 can be various, such as an annular shape, a rectangular ring, etc.

[0128] During the pressure relief process, the pressure relief part 61 can break along the groove 63, so that the opening area 6131 can be opened in a disengaging manner, thereby increasing the pressure relief area of ​​the pressure relief part 61 and improving the pressure relief rate of the pressure relief part 61.

[0129] In some embodiments, please continue to refer to Figure 13 The groove 63 is annular. The annular groove 63 has a simple structure and is easy to form. During pressure relief, the pressure relief part 61 can quickly break along the annular groove 63, so that the opening area 6131 can be opened quickly.

[0130] In some embodiments, please refer to Figure 14 , Figure 14 for Figure 7 The pressure relief device 6 shown is a DD cross-sectional view. The pressure relief section 61 is provided with a first-stage settling tank 62, which is located on the first surface 611.

[0131] The pressure relief section 61 is provided with a primary recess 62, which is the primary recess 62 furthest from the first surface 611. An opening area 6131 is formed on the bottom wall 613 of this primary recess 62. The recess 62 is located on the first surface 611, and understandably, it is recessed from the first surface 611 in the direction facing the second surface 612. When the pressure relief section 61 is provided with a primary recess 62, a primary scoring groove 63 or multiple scoring grooves 63 can be provided on the pressure relief section 61.

[0132] In this embodiment, the pressure relief section 61 is provided with a primary settling tank 62, which is simple to form, improves production efficiency, and reduces production costs.

[0133] In some embodiments, please continue to refer to Figure 14 The pressure relief section 61 is provided with a first-level groove 63, which is located on the bottom surface of the settling tank 62.

[0134] In this embodiment, when the pressure relief section 61 is provided with a first-level recessed groove 62, the pressure relief section 61 is also provided with a first-level scoring groove 63, which is the first-level scoring groove 63 furthest from the first surface 611. The scoring groove 63 is provided on the bottom surface of the recessed groove 62, and it can be understood that the scoring groove 63 is recessed from the bottom surface of the recessed groove 62 in a direction away from the first surface 611.

[0135] In this embodiment, when the pressure relief section 61 is provided with a first-level sink groove 62, the pressure relief section 61 is provided with a first-level scoring groove 63, which simplifies the molding process, improves production efficiency, and reduces production costs.

[0136] In some embodiments, please refer to Figures 15-17 , Figure 15 A top view of the pressure relief device 6 provided in other embodiments of this application; Figure 16 for Figure 15 A partial enlarged view of point E of the pressure relief device 6 shown; Figure 17 for Figure 16 The pressure relief device 6 is shown in a cross-sectional view (FF). The pressure relief section 61 is provided with multi-level grooves 63, which are arranged sequentially along the direction from the first surface 611 to the second surface 612. In two adjacent levels of grooves 63, the first-level groove 63 furthest from the first surface 611 is located on the bottom surface of the first-level groove 63 closest to the first surface 611, and the first-level groove 63 closest to the first surface 611 is located on the bottom surface of the groove 62.

[0137] When the pressure relief section 61 is provided with a first-stage settling groove 62, the pressure relief section 61 can be provided with two-stage, three-stage, four-stage, or five-stage scoring grooves 63. For example... Figure 17 As shown, taking the pressure relief section 61 with two levels of grooves 63 as an example, the first level groove 63 (the first level groove 63 closest to the first surface 611) is set on the bottom surface of the sink 62, and the second level groove 63 (the first level groove 63 furthest from the first surface 611) is set on the bottom surface of the first level groove 63.

[0138] In this embodiment, the multi-level grooves 63 are sequentially arranged along the direction from the first surface 611 to the second surface 612. This reduces the forming depth of each groove 63, thereby reducing the forming force on the pressure relief part 61 during the forming of each groove 63 and lowering the risk of cracking in the pressure relief part 61. During the process of machining the multi-level grooves 63 step-by-step along the direction from the first surface 611 to the second surface 612, the hardness of the residual portion of the pressure relief part 61 in the area where the grooves 63 are located increases with each groove 63 machining. This increases the hardness of the residual portion of the pressure relief part 61 after the multi-level grooves 63 are set, resulting in better long-term reliability, better impact resistance, and a lower probability of breakage from external impacts.

[0139] In some embodiments, the pressure relief section 61 is provided with two or three levels of grooves 63.

[0140] Understandably, when the pressure relief section 61 is provided with a first-stage sink 62, the pressure relief section 61 may be provided with two-stage or three-stage grooves 63.

[0141] For example, in Figure 17 In the middle, the pressure relief section 61 is provided with two-stage grooves 63.

[0142] In some embodiments, please refer to Figures 18-20 , Figure 18 An isometric view of the pressure relief device 6 provided in other embodiments of this application; Figure 19 for Figure 18 A partial enlarged view of point G of the pressure relief device 6 shown. Figure 20 for Figure 18 A partial view of the pressure relief device 6 is shown. The pressure relief section 61 is provided with multi-stage sinkers 62, which are arranged sequentially along the direction from the first surface 611 to the second surface 612. In two adjacent sinkers 62, the first-stage sinker 62 furthest from the first surface 611 is located on the bottom surface of the first-stage sinker 62 closest to the first surface 611. Among them, along the thickness direction Z, the outermost first-stage sinker 62 is located on the first surface 611.

[0143] The pressure relief section 61 can be provided with two, three, four, or five stages of settling tanks 62. The outermost stage settling tank 62 is recessed from the first surface 611 towards the second surface 612. Figure 20 As shown, taking the pressure relief section 61 with two-stage sinkers 62 as an example, the first-stage sinker 62 (the outermost first-stage sinker 62) is located on the first surface 611, and the second-stage sinker 62 is located on the bottom surface of the first-stage sinker 62. The opening area 6131 is formed on the bottom wall 613 of the second-stage sinker 62.

[0144] When the pressure relief section 61 is provided with a multi-stage sink groove 62, the pressure relief section 61 can be provided with a single-stage groove 63 or a multi-stage groove 63.

[0145] The pressure relief section 61 is provided with multi-stage grooves 62, which allows each stage of groove 62 to have a relatively shallow forming depth. This reduces the forming force on the pressure relief section 61 during the forming of each stage of groove 62, thus reducing the risk of cracking. When machining the multi-stage grooves 62 step-by-step along the direction from the first surface 611 to the second surface 612, the hardness of the residual portion of the pressure relief section 61 in the groove 62 area increases with each stage of groove 62 machining, further increasing the hardness of the residual portion of the pressure relief section 61 in the groove 63 area. Furthermore, in the multi-stage grooves 62, the outermost grooves 62 have a larger cross-sectional profile (perpendicular to the thickness direction Z of the pressure relief section 61), providing more clearance space for opening the opening area 6131.

[0146] In some embodiments, please continue to refer to 18- Figure 20 The pressure relief section 61 is provided with a first-level groove 63 along the thickness direction Z. The groove 63 is located on the bottom surface of the first-level sink 62, which is furthest from the first surface 611.

[0147] The first-level settling tank 62 furthest from the first surface 611 is the innermost first-level settling tank 62.

[0148] In this embodiment, when the pressure relief section 61 is provided with multi-stage grooves 62, the pressure relief section 61 is provided with a first-stage groove 63, which is the first-stage groove 63 furthest from the first surface 611. Figure 20 As shown, taking the pressure relief section 61 with two-stage sink 62 as an example, the first-stage sink 62 (the outermost first-stage sink 62) is set on the first surface 611, the second-stage sink 62 (the first-stage sink 62 furthest from the first surface 611) is set on the bottom surface of the first-stage sink 62, and the groove 63 is set on the bottom surface of the second-stage sink 62.

[0149] In this embodiment, when the pressure relief section 61 is provided with a multi-stage sink 62, the pressure relief section 61 is provided with a single-stage scoring groove 63, which simplifies the molding process, improves production efficiency, and reduces production costs.

[0150] In some embodiments, reference Figures 21-23 , Figure 21 An isometric view of the pressure relief device 6 provided in some embodiments of this application; Figure 22 for Figure 21 A partial enlarged view of point H of the pressure relief device 6 shown. Figure 23 for Figure 22The pressure relief device 6 shown is a partial cross-sectional view. The pressure relief section 61 is provided with multi-level grooves 63, which are arranged sequentially along the direction from the first surface 611 to the second surface 612. In two adjacent levels of grooves 63, the first-level groove 63 furthest from the first surface 611 is located on the bottom surface of the first-level groove 63 closest to the first surface 611, and the first-level groove 63 closest to the first surface 611 is located on the bottom surface of the first-level groove 62 furthest from the first surface 611.

[0151] When the pressure relief section 61 is provided with multi-stage grooves 62, the pressure relief section 61 can be provided with two-stage, three-stage, four-stage, or five-stage grooves 63. For example... Figure 23 As shown, taking the pressure relief section 61 with two levels of grooves 63 and two levels of sinkers 62 as an example, the first level sinker 62 (the outermost level sinker 62) is provided on the first surface 611, the second level sinker 62 (the level sinker 62 furthest from the first surface 611) is provided on the bottom surface of the first level sinker 62, the first level groove 63 (the level groove 63 closest to the first surface 611) is provided on the bottom surface of the second level sinker 62, and the second level groove 63 (the level groove 63 furthest from the first surface 611) is provided on the bottom surface of the first level groove 63.

[0152] In this embodiment, the multi-level grooves 63 are sequentially arranged along the direction from the first surface 611 to the second surface 612. This reduces the forming depth of each groove 63, thereby reducing the forming force on the pressure relief part 61 during the forming of each groove 63 and lowering the risk of cracking in the pressure relief part 61. During the process of machining the multi-level grooves 63 step-by-step along the direction from the first surface 611 to the second surface 612, the hardness of the residual portion of the pressure relief part 61 in the area where the grooves 63 are located increases with each groove 63 machining. This increases the hardness of the residual portion of the pressure relief part 61 after the multi-level grooves 63 are set, resulting in better long-term reliability, better impact resistance, and a lower probability of breakage from external impacts.

[0153] In some embodiments, the pressure relief section 61 is provided with two or three levels of grooves 63.

[0154] Understandably, when the pressure relief section 61 is provided with multi-stage sink grooves 62, the pressure relief section 61 can be provided with two-stage or three-stage grooves 63.

[0155] For example, in Figure 23 In the middle, the pressure relief section 61 is provided with two-stage grooves 63.

[0156] In some embodiments, the pressure relief section 61 is provided with two-stage or three-stage settling tanks 62.

[0157] For example, in Figure 23 In the middle, the pressure relief section 61 is equipped with a two-stage settling tank 62.

[0158] In some embodiments, such as Figure 17 and Figure 23 The pressure relief section 61 is provided with multi-level grooves 63. The multi-level grooves 63 are arranged sequentially along the direction from the first surface 611 to the second surface 612. In two adjacent levels of grooves 63, the maximum width of the first-level groove 63 that is far from the first surface 611 is smaller than the minimum width of the first-level groove 63 that is close to the first surface 611.

[0159] Understandably, when the pressure relief section 61 is provided with multi-level grooves 63, the pressure relief section 61 can be provided with a single-level groove 62 or multiple-level grooves 62.

[0160] In two adjacent levels of grooves 63 along the thickness direction Z of the pressure relief section 61, the maximum width of the first-level groove 63 furthest from the first surface 611 is less than the minimum width of the first-level groove 63 closest to the first surface 611. In other words, the width of the multi-level grooves 63 gradually decreases along the direction from the first surface 611 to the second surface 612. The maximum width of the first-level groove 63 furthest from the first surface 611 does not restrict the width of the first-level groove 63 furthest from the first surface 611 in two adjacent levels to be gradually changing. Even if the width of the first-level groove 63 furthest from the first surface 611 does not change along the thickness direction Z of the pressure relief section 61, the width of the first-level groove 63 furthest from the first surface 611 can still be referred to as the maximum width. The minimum width of the first-level groove 63 near the first surface 611 does not limit the width of the first-level groove 63 near the first surface 611 in two adjacent grooves 63 to be gradually changed. When the width of the first-level groove 63 near the first surface 611 does not change along the thickness direction Z of the pressure relief part 61, the width of the first-level groove 63 near the first surface 611 can also be called the minimum width.

[0161] It should be noted that in embodiments where the groove 63 includes a first groove segment 631, a second groove segment 632, and a third groove segment 633, for adjacent levels of grooves 63, it is understood that the maximum width of the first groove segment 631 of the first-level groove 63 farther from the first surface 611 is less than the minimum width of the first groove segment 631 of the first-level groove 63 closer to the first surface 611; the maximum width of the second groove segment 632 of the first-level groove 63 farther from the first surface 611 is less than the minimum width of the second groove segment 632 of the first-level groove 63 closer to the first surface 611; and the maximum width of the third groove segment 633 of the first-level groove 63 farther from the first surface 611 is less than the minimum width of the third groove segment 633 of the first-level groove 63 closer to the first surface 611.

[0162] In this embodiment, the width of each level of groove 63 gradually decreases along the direction from the first surface 611 to the second surface 612. During molding, each level of groove 63 can be formed sequentially along the direction from the first surface 611 to the second surface 612, which facilitates the forming of each level of groove 63.

[0163] In some embodiments, the sink 62 is a rectangular sink or a circular sink.

[0164] If the settling tank 62 is a rectangular tank, the cross-section of the side of the settling tank 62 is rectangular. If the settling tank 62 is a circular tank, the cross-section of the side of the settling tank 62 is circular. The cross-section is perpendicular to the thickness direction Z of the pressure relief section 61.

[0165] For example, in Figures 4-23 In the middle, the settling trough 62 is a rectangular trough.

[0166] In this embodiment, the sink 62 is a rectangular or circular sink. The sink 62 has a simple structure, is easy to form, and can provide more clearance space for opening the opening area 6131.

[0167] In some embodiments, please refer to Figure 14 , Figure 17 , Figure 20 and Figure 23 The first surface 611 is provided with a flange 6111, which surrounds the groove 62 provided on the first surface 611.

[0168] The flange 6111 is a closed structure extending along a closed trajectory. The flange 6111 can be a circular ring or a rectangular ring structure. If the sink 62 is a rectangular sink, the flange 6111 can be set as a rectangular ring structure accordingly; if the sink 62 is a circular sink, the flange 6111 can be set as a circular ring structure accordingly.

[0169] For example, the side surface of the primary sink 62 disposed on the first surface 611 is relative to the edge line of the first surface 611, the edge line is located inside the flange 6111, and there is a distance between the edge line and the inner side surface of the flange 6111.

[0170] The flange 6111 strengthens the pressure relief section 61 and improves the deformation resistance of the pressure relief area of ​​the pressure relief section 61. In addition, the flange 6111 facilitates the installation of protective components to protect the opening area 6131.

[0171] In some embodiments, please continue to refer to Figure 14 , Figure 17 , Figure 20 and Figure 23The pressure relief portion 61 partially protrudes from the second surface 612 in a direction away from the first surface 611 to form a protrusion 6121. The protrusion 6121 includes a groove bottom wall 613 and a reinforcing portion 6121a, which is connected to the second surface 612 and surrounds the groove bottom wall 613.

[0172] The outer contour shape of the protrusion 6121 can be various, such as circular or rectangular. It can be formed by stamping the groove 62 onto the pressure relief part 61, causing a portion of the pressure relief part 61 to protrude along the direction from the first surface 611 to the second surface 612, thus forming a protrusion 6121 protruding from the second surface 612. The primary groove 62 furthest from the first surface 611 is located within the protrusion 6121; that is, the bottom surface of the primary groove 62 furthest from the first surface 611 is further away from the first surface 611 than the second surface 612, so that the reinforcing part 6121a is provided around the primary groove 62 furthest from the first surface 611.

[0173] In an embodiment where the pressure relief section 61 is provided with a notch 66, the notch 66 may be provided on the surface of the protrusion 6121 that is away from the second surface 612.

[0174] In an embodiment where the pressure relief portion 61 is provided with a flange 6111, the projection of the inner side surface of the flange 6111 along the thickness direction Z of the pressure relief portion 61 may be located on the protrusion 6121, further enhancing the deformation resistance of the pressure relief area of ​​the pressure relief portion 61.

[0175] In this embodiment, the reinforcing part 6121a is connected to the second surface 612, which can strengthen the bottom wall 613 of the groove, improve the deformation resistance of the bottom wall 613 of the groove, and reduce the risk of stress damage at the location where the groove 63 is set on the bottom wall 613 of the groove.

[0176] In some embodiments, please continue to refer to Figure 14 , Figure 17 , Figure 20 and Figure 23 The second surface 612 is provided with a groove 6122, which surrounds the protrusion 6121.

[0177] The groove 6122 is a closed structure extending along a closed trajectory. The shape of the groove 6122 can be various, such as an annular or rectangular ring. If the outer contour of the protrusion 6121 is a circular structure, the groove 6122 can be set as an annular structure accordingly; if the outer contour of the protrusion 6121 is a rectangular structure, the groove 6122 can be set as a rectangular ring accordingly.

[0178] The groove 6122 can absorb the energy transmitted from the pressure relief part 61 to the protrusion 6121, and even if the pressure relief part 61 is deformed, it is not easy to be transmitted to the area where the groove 63 is set.

[0179] In some embodiments, please continue to refer to Figure 14 , Figure 17 , Figure 20 and Figure 23 Along the thickness direction Z, the height of the protrusion 6121 protruding from the second surface 612 is H1, and the distance between the first surface 611 and the second surface 612 is H2, satisfying: H1≥H2.

[0180] Along the thickness direction Z, the height by which the protrusion 6121 protrudes from the second surface 612 is the distance between the surface of the protrusion 6121 facing away from the second surface 612 and the second surface 612, and the distance between the first surface 611 and the second surface 612 is the thickness of the pressure relief part 61.

[0181] In this embodiment, H1≥H2, which makes the height of the protrusion 6121 protruding from the second surface 612 larger, thereby enhancing the reinforcing effect of the reinforcing part 6121a on the bottom wall 613 of the groove.

[0182] In some embodiments, please refer to Figures 4-23 The pressure relief part 61 is an end cap 3, which is used to close the opening of the housing 1.

[0183] The first surface 611 can be the outer surface of the end cap 3, and the second surface 612 can be the inner surface of the end cap 3; or the first surface 611 can be the inner surface of the end cap 3, and the second surface 612 can be the outer surface of the end cap 3. The outer surface of the end cap 3 is the surface of the end cap 3 that faces away from the housing 1, and the inner surface of the end cap 3 is the surface of the end cap 3 that faces the housing 1.

[0184] In this embodiment, the end cap 3 has a pressure relief function. The pressure relief structure is formed by setting a groove 63 on the end cap 3. The pressure relief structure has better stability and good long-term reliability.

[0185] In some embodiments, the first surface 611 is the surface of the end cap 3 that faces away from the housing 1. The surface of the end cap 3 that faces away from the housing 1 is the outer surface of the end cap 3, and even if the outer surface of the end cap 3 is blocked by an obstacle, the opening area 6131 can still be opened to release pressure.

[0186] In some embodiments, please refer to Figure 24 and Figure 25 , Figure 24 An isometric view of the pressure relief device 6 provided in other embodiments of this application; Figure 25 for Figure 24 The enlarged view of part I of the pressure relief device 6 is shown. The pressure relief device 6 is a housing 1, and an accommodating space is formed inside the housing 1. The housing 1 includes multiple walls that together define the accommodating space, which is used to accommodate the electrode assembly 2. At least one wall is a pressure relief part 61.

[0187] In the housing 1, there can be one or more wall sections serving as pressure relief sections 61. If multiple wall sections serve as pressure relief sections 61, then the housing 1 will have multiple pressure relief sections 61. The first surface 611 of the pressure relief section 61 can be either the outer surface or the inner surface of the wall section. The outer surface of the wall section is the surface of the wall section facing away from the electrode assembly 2, and the inner surface of the wall section is the surface of the wall section facing the electrode assembly 2.

[0188] In this embodiment, the pressure relief device 6 has both the function of accommodating the electrode assembly 2 and the function of relieving pressure.

[0189] In some embodiments, please continue to refer to Figure 24 The housing 1 includes a peripheral wall 67 and a bottom wall 68. The peripheral wall 67 surrounds the edge of the bottom wall 68. The peripheral wall 67 and the bottom wall 68 together define an accommodating space. An opening is formed at the opposite end of the peripheral wall 67 and the bottom wall 68. The bottom wall 68 is a pressure relief part 61.

[0190] The peripheral wall 67 surrounds the edge of the bottom wall 68, allowing the housing 1 to form an opening at the opposite end of the bottom wall 68, and the end cap 3 is used to cover the opening. The peripheral wall 67 and the bottom wall 68 are integrally formed structures.

[0191] In embodiments where the housing 1 is cylindrical, the housing 1 may have two walls: a bottom wall 68 and a cylindrical peripheral wall 67. For example... Figure 24 As shown, in an embodiment where the shell 1 is a cuboid, the shell 1 may have five walls, a bottom wall 68 and four side walls, with the four side walls connected end to end to form a peripheral wall 67.

[0192] In this embodiment, since the bottom wall 68 is a pressure relief part 61, the bottom wall 68 of the pressure relief device 6 has a pressure relief function, which facilitates the release of pressure inside the containment space.

[0193] In some embodiments, the first surface 611 is the outer surface of the wall.

[0194] Understandably, in embodiments where the bottom wall 68 is a pressure relief section 61, the first surface 611 is the outer surface of the bottom wall 68.

[0195] When forming the recessed groove 62 and the scoring groove 63 on the wall, the scoring groove 63 can be formed on the outside of the wall, which makes the forming process more convenient.

[0196] This application provides a battery cell 10, including the pressure relief device 6 provided in any of the above embodiments.

[0197] This application provides a battery 100, including the battery cell 10 provided in any of the above embodiments.

[0198] This application provides an electrical device, including the battery 100 provided in any of the above embodiments.

[0199] The electrical equipment can be any of the devices that use battery 100 as described above.

[0200] Please refer to Figures 4-7 This application provides an end cap 3, which has a first surface 611 and a second surface 612 opposite to each other in its thickness direction Z. The end cap 3 is provided with a primary recessed groove 62 and a primary scoring groove 63, which are arranged sequentially along the direction from the first surface 611 to the second surface 612. The bottom wall 613 of the recessed groove 62 has an opening area 6131, and the scoring groove 63 is provided along the edge of the opening area 6131. ​​The opening area 6131 is configured to be able to be opened with the scoring groove 63 as the boundary. The recessed groove 62 is a rectangular groove. The groove 63 includes a first groove segment 631, a second groove segment 632, and a third groove segment 633. The first groove segment 631 and the second groove segment 632 are arranged opposite to each other and intersect with the third groove segment 633. The first groove segment 631, the second groove segment 632, and the third groove segment 633 are arranged along the edge of the opening area 6131. ​​The first groove segment 631, the second groove segment 632, and the third groove segment 633 form an H-shape. The first groove segment 631, the second groove segment 632, and the third groove segment 633 together define two opening areas 6131, which are located on both sides of the third groove segment 633.

[0201] Please refer to Figure 24 and Figure 25 This application embodiment also provides a housing 1, which is a cuboid structure. The bottom wall 68 of the housing 1 is provided with a primary recess 62 and a secondary groove 63. The primary recess 62 and the secondary groove 63 are arranged sequentially along the direction from the first surface 611 to the second surface 612. The recess 62 is a rectangular groove located on the first surface 611. The bottom wall 613 of the recess 62 has an opening area 6131. ​​The groove 63 is arranged along the edge of the opening area 6131. ​​The opening area 6131 is configured to open with the primary groove 63 furthest from the first surface 611 as its boundary. The groove 63 includes a first groove segment 631, a second groove segment 632, and a third groove segment 633. The first groove segment 631 and the second groove segment 632 are arranged opposite to each other, and both the first groove segment 631 and the second groove segment 632 intersect with the third groove segment 633. The first groove segment 631, the second groove segment 632, and the third groove segment 633 are arranged along the edge of the opening area 6131, and together they define two opening areas 6131, which are located on both sides of the third groove segment 633. The pressure relief part 61 is provided with a fourth groove segment 64, which is located between the first groove segment 631 and the second groove segment 632, and intersects with the third groove segment 633.

[0202] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0203] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit this application. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A pressure relief device, characterized in that, include: The pressure relief section has a first surface and a second surface that are disposed opposite to each other in its thickness direction; At least one sink groove and at least one scoring groove are provided sequentially on the pressure relief section along the direction from the first surface to the second surface; The bottom wall of the first-level sink furthest from the first surface has an opening area, and the scoring groove is provided along the edge of the opening area. The opening area is configured to be able to be opened with the first-level scoring groove furthest from the first surface as the boundary. A portion of the pressure relief section protrudes from the second surface in a direction away from the first surface to form a protrusion. The protrusion includes the bottom wall of the groove and a reinforcing portion. The reinforcing portion is connected to the second surface and surrounds the bottom wall of the groove.

2. The pressure relief device according to claim 1, characterized in that, The groove includes a first groove segment, a second groove segment, and a third groove segment. The first groove segment and the second groove segment are arranged opposite to each other, and both the first groove segment and the second groove segment intersect with the third groove segment. The first groove segment, the second groove segment, and the third groove segment are arranged along the edge of the opening area.

3. The pressure relief device according to claim 2, characterized in that, The pressure relief section is provided with a fourth groove segment, which is located between the first groove segment and the second groove segment, and intersects with the third groove segment.

4. The pressure relief device according to claim 3, characterized in that, The fourth slot segment intersects the third slot segment at the intersection point. In the extending direction of the third slot segment, the distance from the intersection point to the first slot segment is equal to the distance from the intersection point to the second slot segment.

5. The pressure relief device according to claim 2, characterized in that, The pressure relief section is provided with a fifth groove segment. In the first-level groove furthest from the first surface, the bottom surface of one or both of the first groove segment, the second groove segment, and the third groove segment is provided with the fifth groove segment.

6. The pressure relief device according to claim 2, characterized in that, The first slot segment, the second slot segment, and the third slot segment together define at least one of the opening areas.

7. The pressure relief device according to claim 2, characterized in that, The first slot segment, the second slot segment, and the third slot segment define two opening areas, which are located on opposite sides of the third slot segment.

8. The pressure relief device according to claim 2, characterized in that, The groove also includes a sixth groove segment, which is disposed opposite to the third groove segment. The first groove segment and the second groove segment both intersect with the sixth groove segment. The first groove segment, the second groove segment, the third groove segment, and the sixth groove segment together define the opening area.

9. The pressure relief device according to claim 1, characterized in that, The groove is a non-closed groove that extends along a non-closed trajectory that is not connected at either end.

10. The pressure relief device according to claim 9, characterized in that, The groove is arc-shaped.

11. The pressure relief device according to claim 1, characterized in that, The groove is a closed groove that extends along a closed trajectory connecting the two ends.

12. The pressure relief device according to claim 11, characterized in that, The groove is circular.

13. The pressure relief device according to any one of claims 1-12, characterized in that, The pressure relief section is provided with a settling tank, which is located on the first surface.

14. The pressure relief device according to claim 13, characterized in that, The pressure relief section is provided with a first-level groove, which is located on the bottom surface of the settling tank.

15. The pressure relief device according to claim 14, characterized in that, The pressure relief section is provided with multiple levels of grooves, which are arranged sequentially along the direction from the first surface to the second surface. In two adjacent levels of grooves, the first-level groove furthest from the first surface is located on the bottom surface of the first-level groove closest to the first surface, and the first-level groove closest to the first surface is located on the bottom surface of the groove.

16. The pressure relief device according to claim 15, characterized in that, The pressure relief section is provided with two or three levels of grooves.

17. The pressure relief device according to any one of claims 1-12, characterized in that, The pressure relief section is provided with multiple stages of sinking troughs, which are arranged sequentially along the direction from the first surface to the second surface. In two adjacent stages of sinking troughs, the stage of sinking trough furthest from the first surface is located on the bottom surface of the stage of sinking trough closest to the first surface. Wherein, along the thickness direction, the outermost first-level sink is disposed on the first surface.

18. The pressure relief device according to claim 17, characterized in that, The pressure relief section is provided with a first-level groove, which is located on the bottom surface of the first-level groove furthest from the first surface along the thickness direction.

19. The pressure relief device according to claim 17, characterized in that, The pressure relief section is provided with multiple levels of grooves, which are arranged sequentially along the direction from the first surface to the second surface. In two adjacent levels of grooves, the first level groove that is far from the first surface is located on the bottom surface of the first level groove that is close to the first surface, and the first level groove that is closest to the first surface is located on the bottom surface of the first level groove that is farthest from the first surface.

20. The pressure relief device according to claim 19, characterized in that, The pressure relief section is provided with two or three levels of grooves.

21. The pressure relief device according to claim 17, characterized in that, The pressure relief section is provided with two or three stages of settling tanks.

22. The pressure relief device according to any one of claims 1-12, characterized in that, The pressure relief section is provided with multiple levels of grooves, which are arranged sequentially along the direction from the first surface to the second surface. In two adjacent levels of grooves, the maximum width of the first level groove farther from the first surface is smaller than the minimum width of the first level groove closer to the first surface.

23. The pressure relief device according to any one of claims 1-12, characterized in that, The settling trough is a rectangular trough or a circular trough.

24. The pressure relief device according to any one of claims 1-12, characterized in that, The first surface is provided with a flange, which surrounds the groove provided on the first surface.

25. The pressure relief device according to any one of claims 1-12, characterized in that, The second surface is provided with a groove, which surrounds the protrusion.

26. The pressure relief device according to any one of claims 1-12, characterized in that, Along the thickness direction, the height of the protrusion protruding from the second surface is H1, and the distance between the first surface and the second surface is H2, satisfying: H1≥H2.

27. The pressure relief device according to any one of claims 1-12, characterized in that, The pressure relief section is an end cap, which is used to close the opening of the housing.

28. The pressure relief device according to claim 27, characterized in that, The first surface is the surface of the end cap that faces away from the housing.

29. The pressure relief device according to any one of claims 1-12, characterized in that, The pressure relief device is a housing, and an accommodating space is formed inside the housing. The housing includes multiple walls, which together define the accommodating space. The accommodating space is used to accommodate the electrode assembly, and at least one of the walls is the pressure relief section.

30. The pressure relief device according to claim 29, characterized in that, The housing includes a peripheral wall and a bottom wall. The peripheral wall surrounds the edge of the bottom wall, and the peripheral wall and the bottom wall together define the receiving space. An opening is formed at one end of the peripheral wall opposite to the bottom wall, and the bottom wall is the pressure relief part.

31. The pressure relief device according to claim 29, characterized in that, The first surface is the outer surface of the wall portion.

32. A single battery cell, characterized in that, Includes the pressure relief device as described in any one of claims 1-31.

33. A battery, characterized in that, Includes the battery cell as described in claim 32.

34. An electrical appliance, characterized in that, Includes the battery as described in claim 33.

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