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 body and a plurality of notch grooves. The pressure relief body comprises a pressure relief part, and the pressure relief part has opposite first and second surfaces in the thickness direction. The plurality of notch grooves are arranged in the direction from the first surface to the second surface in the pressure relief part, and in the thickness direction, the maximum width of the notch groove away from the first surface is smaller than the minimum width of the notch groove close to the first surface. The pressure relief device with the structure adopts a multi-stage notch groove structure, can reduce the forming force borne by the pressure relief part when forming each stage of notch groove, reduces the risk of cracks in the pressure relief part, the pressure relief device is not prone to failure due to cracks in the position of the pressure relief part where the notch groove is arranged, and the long-term reliability of the pressure relief device is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a pressure relief device, a battery monomer, a battery and an electric device. BACKGROUND

[0002] Batteries are widely used in electronic devices, such as mobile phones, notebook computers, electric vehicles, electric cars, electric planes, electric ships, electric toy cars, electric toy ships, electric toy planes and electric tools.

[0003] In the battery technology, in order to ensure the safety of the battery monomer, a pressure relief device is generally arranged in the battery monomer. When the internal temperature of the battery monomer reaches a threshold value, the pressure relief device breaks at the position where the notch groove is arranged, so as to release the pressure inside the battery monomer. For a general pressure relief device, the pressure relief may also occur when the internal pressure of the battery monomer is within a normal range, and the long-term reliability is poor. SUMMARY

[0004] The embodiments of the present application provide a pressure relief device, a battery monomer, a battery and an electric device, which can effectively improve the long-term reliability of the pressure relief device.

[0005] In a first aspect, the embodiments of the present application provide a pressure relief device, comprising: a pressure relief body comprising a pressure relief part, the pressure relief part having opposite first and second surfaces in a thickness direction thereof; and a plurality of notch grooves arranged in sequence along a direction from the first surface to the second surface of the pressure relief part, wherein in two adjacent notch grooves in the thickness direction of the pressure relief part, a maximum width of a notch groove away from the first surface is less than a minimum width of a notch groove close to the first surface.

[0006] In the above technical solution, the pressure relief part is provided with a plurality of notch grooves, the plurality of notch grooves are arranged in sequence along a direction from the first surface to the second surface of the pressure relief part, and in two adjacent notch grooves in the thickness direction of the pressure relief part, a maximum width of a notch groove away from the first surface is less than a minimum width of a notch groove close to the first surface. The pressure relief device with such a structure adopts a multi-stage notch groove structure, which can reduce the forming force on the pressure relief part when forming each stage of notch groove, reduce the risk of cracks in the pressure relief part, and improve the long-term reliability of the pressure relief device.

[0007] In some embodiments, the plurality of notch grooves comprises first notch grooves and second notch grooves with consistent extension directions, and the first notch grooves are arranged on the bottom surface of the second notch grooves.

[0008] In the technical solution, the extension direction of the first score groove is consistent with the extension direction of the second score groove, and the first score groove is arranged on the bottom surface of the second score groove. This structure can facilitate the forming of the first score groove and ensure the length of the first score groove, and can also ensure that the maximum width of the first score groove is smaller than the minimum width of the second score groove.

[0009] In some embodiments, the plurality of score grooves further comprises a third score groove arranged on the first surface, and the second score groove is arranged on the bottom surface of the third score groove.

[0010] In the technical solution, the plurality of score grooves further comprises a third score groove arranged on the first surface, and the second score groove is arranged on the bottom surface of the third score groove. That is, three levels of score grooves are arranged on the pressure relief part, so that the forming force acting on the pressure relief part during the forming of each level of score groove is not too large, and the risk of crack of the pressure relief part is reduced.

[0011] In some embodiments, the bottom surface of the third score groove is provided with a plurality of second score grooves.

[0012] In the technical solution, the bottom surface of the third score groove is provided with a plurality of second score grooves, so that the pressure relief part can be broken at the positions of the second score grooves to achieve pressure relief, and the pressure relief effect is better, and the pressure relief rate is improved. In addition, since one third score groove corresponds to a plurality of second score grooves, the forming process can be simplified, and the forming cost is reduced.

[0013] In some embodiments, the plurality of second score grooves comprises a first groove segment, a second groove segment and a third groove segment, the first groove segment and the second groove segment are arranged at intervals, and the first groove segment and the second groove segment both intersect with the third groove segment; the pressure relief part comprises an opening area jointly defined by the first groove segment, the second groove segment and the third groove segment, and the opening area is configured to be opened with the first groove segment, the second groove segment and the third groove segment as boundaries.

[0014] In the technical solution, the first groove segment and the second groove segment are arranged at intervals, the second groove segment and the second groove segment both intersect with the third groove segment, the first groove segment, the second groove segment and the third groove segment jointly define an opening area, and after the pressure relief part is broken at the positions of the first groove segment, the second groove segment and the second groove segment, the part of the pressure relief part located in the opening area will be opened to relieve pressure, the pressure relief area of the pressure relief part is increased, and the pressure relief rate of the pressure relief part is improved.

[0015] In some embodiments, the plurality of second score grooves further comprises a fourth groove segment, and in the extension direction of the third groove segment, the fourth groove segment is located between the first groove segment and the second groove segment, and the fourth groove segment intersects with the third groove segment.

[0016] In the technical solution, the fourth groove section intersects with the third groove section, and the stress of the pressure relief part is more concentrated at the intersection position of the third groove section and the fourth groove section, so that the pressure relief part is more likely to break at the intersection position of the third groove section and the fourth groove section, and the pressure relief part breaks along the third groove section from the intersection position of the third groove section and the fourth groove section during the pressure relief process, and then breaks along the first groove section and the second groove section after the third groove section breaks, so that the pressure relief part can be quickly relieved.

[0017] In some embodiments, in the extension direction of the third groove section, the distance from the intersection position of the fourth groove section and the third groove section to the first groove section is equal to the distance from the intersection position of the fourth groove section and the third groove section to the second groove section.

[0018] In the technical solution, the distance from the intersection position of the fourth groove section and the third groove section to the first groove section is equal to the distance from the intersection position of the fourth groove section and the third groove section to the second groove section, so that the pressure relief part can break along the first groove section and the second groove section synchronously after breaking along the third groove section at the intersection position of the fourth groove section and the third groove section.

[0019] In some embodiments, the pressure relief body is provided with a plurality of first score grooves corresponding to the second score grooves one by one; the plurality of first score grooves include a fifth groove section, a sixth groove section and a seventh groove section, the fifth groove section is arranged on the bottom surface of the first groove section, the sixth groove section is arranged on the bottom surface of the second groove section, and the seventh groove section is arranged on the bottom surface of the third groove section.

[0020] In some embodiments, the plurality of second score grooves further include a fourth groove section, the fourth groove section is located between the first groove section and the second groove section in the extension direction of the third groove section, and the fourth groove section intersects with the third groove section; the plurality of first score grooves further include an eighth groove section, and the eighth groove section is arranged on the bottom surface of the fourth groove section.

[0021] In some embodiments, the first groove section, the second groove section and the third groove section define two opening areas, and the two opening areas are respectively located on both sides of the third groove section.

[0022] In the technical solution, the first groove section, the second groove section and the third groove section define two opening areas, and the two opening areas are respectively located on both sides of the third groove section, so that the part of the pressure relief part in the two pressure relief areas can open the pressure relief in a split manner during the pressure relief process, and the pressure relief rate of the pressure relief part can be effectively improved.

[0023] In some embodiments, the second surface is provided with a notch groove located in the opening area, and the notch groove is away from the third groove section in the extension direction of the first groove section.

[0024] In the technical solution, the gap groove is away from the third groove segment in the extension direction of the first groove segment, and at least part of the gap groove is located in the opening area, so that in the pressure relief process, the part of the pressure relief part located in the opening area can be flipped around the position of the pressure relief part located in the gap groove, and the pressure relief part is more easily opened.

[0025] In some embodiments, the distance between the first surface and the second surface is H0, the distance from the bottom surface of the score groove closest to the second surface to the second surface is H1, and H0 and H1 satisfy the relationship H1 / H0<0.2.

[0026] In the technical solution, the ratio of the distance from the bottom surface of the score groove closest to the second surface to the second surface to the distance between the first surface and the second surface is less than 0.2, so that the thickness of the part between the bottom surface of the score groove closest to the second surface and the second surface accounts for a small proportion in the total thickness of the pressure relief part, and the part between the bottom surface of the score groove closest to the second surface and the second surface can be normally broken to achieve pressure relief.

[0027] In some embodiments, the distance from the bottom surface of the score groove closest to the second surface to the second surface is H1, and H1 satisfies the relationship H1<0.5mm.

[0028] In the technical solution, the distance from the bottom surface of the score groove closest to the second surface to the second surface is less than 0.5mm, so that the thickness of the part between the bottom surface of the score groove closest to the second surface and the second surface is small, and the part is easy to break to relieve pressure.

[0029] In some embodiments, the depth of the score groove provided on the first surface is H2, and H2 satisfies the relationship H2<1mm.

[0030] In the technical solution, the depth of the score groove provided on the first surface is less than 1mm, so that the depth of the score groove on the outermost side of the pressure relief part is small, the forming force on the pressure relief part in the forming process is reduced, and the risk of cracks in the pressure relief part is reduced.

[0031] In some embodiments, the depth of the score groove between the score groove closest to the second surface and the score groove provided on the first surface is H3, and H3 satisfies the relationship H3<1.5mm.

[0032] In the technical solution, the depth of the score groove between the score groove closest to the second surface and the score groove provided on the first surface is less than 1.5mm, so that the depth of the score groove on the pressure relief part except the score groove closest to the second surface and the score groove provided on the first surface is small, the forming force on the pressure relief part in the forming process is reduced, and the risk of cracks in the pressure relief part is reduced.

[0033] In some embodiments, the pressure relief body has a receiving space formed inside, the pressure relief body has a plurality of walls defining the receiving space, and one of the plurality of walls has the pressure relief portion.

[0034] In the technical solution, the plurality of walls of the pressure relief body define a receiving cavity for receiving the electrode assembly, and one of the plurality of walls has the pressure relief portion, so that the pressure relief device has both the receiving function and the pressure relief function.

[0035] In some embodiments, the plurality of walls include a peripheral wall and a bottom wall, the peripheral wall is arranged at the edge of the bottom wall, the peripheral wall and the bottom wall jointly define the receiving space, and the bottom wall has the pressure relief portion.

[0036] In the technical solution, the bottom wall of the pressure relief body has the pressure relief portion, so that the bottom wall has good pressure relief function.

[0037] In some embodiments, the peripheral wall and the bottom wall are integrally formed.

[0038] In the technical solution, the bottom wall has the pressure relief portion, and the peripheral wall and the bottom wall are integrally formed, so that the peripheral wall and the bottom wall with the pressure relief function have good firmness, and the integrated design can simplify the forming process and reduce production cost.

[0039] In some embodiments, the first surface is an outer surface of the bottom wall.

[0040] In the technical solution, the first surface is an outer surface of the bottom wall, so that the score groove can be easily machined on the pressure relief body.

[0041] In a second aspect, the embodiments of the present application provide a battery monomer, which comprises the pressure relief device provided by any one of the embodiments of the first aspect.

[0042] In a third aspect, a battery is provided, which comprises the battery monomer provided by any one of the embodiments of the second aspect, and a box body for accommodating the battery monomer.

[0043] In a fourth aspect, a power consumption device is provided, which comprises the battery provided by any one of the embodiments of the third aspect.

[0044] In a fifth aspect, the embodiments of the present application provide a manufacturing method of a pressure relief device, which comprises: providing a pressure relief body, the pressure relief body comprising a pressure relief portion, the pressure relief portion having opposite first and second surfaces in a thickness direction; sequentially machining a plurality of score grooves on the pressure relief portion in a direction from the first surface to the second surface; and in two adjacent score grooves in the thickness direction, a maximum width of a score groove away from the first surface is smaller than a minimum width of a score groove close to the first surface.

[0045] In some embodiments, the step of sequentially machining a plurality of grooves on the pressure relief portion along the direction from the first surface to the second surface includes: sequentially punching a plurality of grooves on the pressure relief portion along the direction from the first surface to the second surface.

[0046] In the above technical solution, multiple grooves are sequentially formed on the pressure relief part from the first surface to the second surface by stamping. The forming process is simple and can reduce the stamping pressure on the pressure relief part when stamping each level of grooves, thereby reducing the risk of cracks in the pressure relief part.

[0047] In a sixth aspect, embodiments of this application provide a manufacturing apparatus for a pressure relief device, comprising: a first providing device for providing a pressure relief body, the pressure relief body including a pressure relief portion having opposing first and second surfaces in its thickness direction; and a processing device for sequentially processing a plurality of grooves on the pressure relief portion along a direction from the first surface to the second surface; wherein, in two adjacent grooves in the thickness direction, the maximum width of the groove farther from the first surface is smaller than the minimum width of the groove closer to the first surface. Attached Figure Description

[0048] 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.

[0049] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0050] Figure 2 This application provides schematic diagrams of the battery structure for some embodiments.

[0051] Figure 3 Exploded views of a single battery cell provided in some embodiments of this application;

[0052] Figure 4 This is a schematic diagram of the structure of a pressure relief device provided in some embodiments of this application;

[0053] Figure 5 for Figure 4 The cross-sectional view of the pressure relief section is shown below;

[0054] Figure 6 A partial view of a pressure relief device provided in some embodiments of this application;

[0055] Figure 7 for Figure 6 The cross-sectional view of the pressure relief section is shown below;

[0056] Figure 8 for Figure 6 The diagram shows the positional relationship between the first, second, and third grooves.

[0057] Figure 9 Schematic diagram of the structure of a pressure relief device provided in some embodiments of this application;

[0058] Figure 10 Flowcharts illustrating methods for manufacturing pressure relief devices provided in some embodiments of this application;

[0059] Figure 11 A schematic block diagram of a manufacturing apparatus for a pressure relief device provided in some embodiments of this application.

[0060] Icons: 10-Box; 11-First part; 12-Second part; 20-Battery cell; 21-Housing shell; 22-Electrode assembly; 221-Positive electrode tab; 222-Negative electrode tab; 23-End cap; 231-Positive electrode terminal; 232-Negative electrode terminal; 24-Insulator; 25-Pressure relief device; 251-Pressure relief body; 2511-Pressure relief section; 2511a-First surface; 2511b-Second surface; 2511c-Opening area; 2512-Peripheral wall; 2513-Bottom wall; 252-Groove; 2521-First Scoring groove; 2521a - Fifth groove segment; 2521b - Sixth groove segment; 2521c - Seventh groove segment; 2521d - Eighth groove segment; 2522 - Second scoring groove; 2522a - First groove segment; 2522b - Second groove segment; 2522c - Third groove segment; 2522d - Fourth groove segment; 2523 - Third scoring groove; 253 - Notch groove; 26 - Current collector component; 100 - Battery; 200 - Controller; 300 - Motor; 1000 - Vehicle; 2000 - Manufacturing equipment; 2100 - Supply device; 2200 - Processing device. Detailed Implementation

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] In this application, "multiple" means two or more (including two).

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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 on their body. 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 on the pressure relief body are formed, cracks are prone to occur, resulting in pressure leakage even when the internal pressure of the battery cell is within the normal range (below the threshold).

[0074] In view of this, the present application provides a pressure relief device in which a plurality of grooves are arranged sequentially from the first surface to the second surface on the pressure relief part of the pressure relief body, and in two adjacent grooves in the thickness direction of the pressure relief part, the maximum width of the groove farther from the first surface is smaller than the minimum width of the groove closer to the first surface.

[0075] In such a pressure relief device, a multi-stage groove structure is adopted, which can reduce the forming force on the pressure relief part when forming each groove, reduce the risk of cracking in the pressure relief part, and make the pressure relief device less likely to fail due to cracks in the pressure relief part at the location where the groove is set, thereby improving the long-term reliability of the pressure relief device.

[0076] The technical solutions described in the embodiments of this application are applicable to batteries and electrical devices that use batteries.

[0077] 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.

[0078] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0079] Please refer to Figure 1 , Figure 1 The diagram below illustrates the structure of a vehicle 1000 according to some embodiments of this application. A battery 100 is disposed inside the vehicle 1000, and the battery 100 may be located at the bottom, head, or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000.

[0080] 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.

[0081] 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.

[0082] Please refer to Figure 2 , Figure 2 The present invention provides a schematic diagram of the structure of a battery 100 according to some embodiments. The battery 100 includes a housing 10 and a battery cell 20. The housing 10 is used to house the battery cell 20.

[0083] The housing 10 is a component that houses the battery cell 20, providing a storage space for the battery cell 20. The housing 10 can have various structures. In some embodiments, the housing 10 may include a first part 11 and a second part 12, which overlap each other to define a storage space for accommodating the battery cell 20. The first part 11 and the second part 12 can have various shapes, such as a cuboid or a cylinder. The first part 11 can be a hollow structure open on one side, and the second part 12 can also be a hollow structure open on one side, with the open side of the second part 12 overlapping the open side of the first part 11, thus forming a housing 10 with a storage space. Alternatively, the first part 11 can be a hollow structure open on one side, and the second part 12 can be a plate-like structure, with the second part 12 overlapping the open side of the first part 11, thus forming a housing 10 with a storage space. The first part 11 and the second part 12 can be sealed using a sealing element, such as a sealing ring or sealant.

[0084] In battery 100, there can be one or more battery cells 20. If there are multiple battery cells 20, they can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel. Alternatively, multiple battery cells 20 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 10. Another option is that all battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the whole consisting of all battery cells 20 is housed within the housing 10.

[0085] In some embodiments, the battery 100 may further include a busbar component, through which multiple battery cells 20 can be electrically connected to each other, enabling series, parallel, or mixed connection of the multiple battery cells 20. The busbar component may be a metallic conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0086] Please refer to Figure 3 , Figure 3 The exploded view of a battery cell 20 provided in some embodiments of this application shows that the battery cell 20 includes a housing 21, an electrode assembly 22, an end cap 23, an insulating component 24, and a pressure relief device 25.

[0087] The housing 21 is a component used to house the electrode assembly 22. The housing 21 can be a hollow structure with an opening at one end. The housing 21 can be of various shapes, such as a cylinder or a cuboid. The housing 21 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy.

[0088] The electrode assembly 22 within the housing 21 can be one or more. For example, such as Figure 3 As shown, there are multiple electrode assemblies 22, which are stacked and arranged inside the housing 21.

[0089] Electrode assembly 22 is the component in the battery cell 20 where the electrochemical reaction takes place. Electrode assembly 22 may include a positive electrode, a negative electrode, and a separator. Electrode assembly 22 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.

[0090] 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 22 has a positive electrode tab 221 and a negative electrode tab 222. The positive electrode tab 221 may be a portion of the positive electrode that is not coated with a positive active material layer, and the negative electrode tab 222 may be a portion of the negative electrode that is not coated with a negative active material layer.

[0091] End cap 23 is a component that closes onto the opening of housing 21 to isolate the internal environment of battery cell 20 from the external environment. End cap 23 closes onto the opening of housing 21, and end cap 23 and housing 21 together define a sealed space for accommodating electrode assembly 22, electrolyte, and other components. The shape of end cap 23 can be adapted to the shape of housing 21. For example, if housing 21 is a cuboid structure, end cap 23 can be a rectangular plate structure adapted to housing 21; or if housing 21 is a cylindrical structure, end cap 23 can be a circular plate structure adapted to housing 21. The material of end cap 23 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of end cap 23 can be the same as or different from the material of housing 21.

[0092] Electrode terminals can be provided on the end cap 23. These terminals are used to electrically connect to the electrode assembly 22 to output electrical energy from the battery cell 20. The electrode terminals may include a positive electrode terminal 231 and a negative electrode terminal 232. The positive electrode terminal 231 is used to electrically connect to the positive electrode tab 221, and the negative electrode terminal 232 is used to electrically connect to the negative electrode tab 222. The positive electrode terminal 231 and the positive electrode tab 221 can be directly connected or indirectly connected, as can the negative electrode terminal 232 and the negative electrode tab 222. For example, the positive electrode terminal 231 is electrically connected to the positive electrode tab 221 through a current collector 26, and the negative electrode terminal 232 is electrically connected to the negative electrode tab 222 through another current collector 26.

[0093] The insulating member 24 is a component that separates the housing 21 from the electrode assembly 22, achieving insulation isolation between the housing 21 and the electrode assembly 22. The insulating member 24 is made of an insulating material, such as plastic or rubber. For example, the insulating member 24 circumferentially covers the outer periphery of the electrode assembly 22. It can be understood that when there are multiple electrode assemblies 22, the insulating member 24 circumferentially covers the outer periphery of all multiple electrode assemblies 22.

[0094] The pressure relief device 25 is a component that releases pressure inside the battery cell 20. When the pressure or temperature inside the battery cell 20 reaches a threshold, the pressure is released through the pressure relief device 25. The pressure relief device 25 can be a component installed on the end cap 23 or it can be a component of the housing 21. The specific structure of the pressure relief device 25 will be described in detail below with reference to the accompanying drawings.

[0095] Please refer to Figure 4 and Figure 5 , Figure 4 This is a schematic diagram of the structure of the pressure relief device 25 provided in some embodiments of this application. Figure 5 for Figure 4The pressure relief portion 2511 shown is a cross-sectional view. The pressure relief device 25 includes a pressure relief body 251 and a plurality of grooves 252. The pressure relief body 251 includes a pressure relief portion 2511, which has opposing first surfaces 2511a and second surfaces 2511b in its thickness direction. The plurality of grooves 252 are arranged sequentially on the pressure relief portion 2511 along the direction from the first surface 2511a to the second surface 2511b. In two adjacent grooves 252 in the thickness direction of the pressure relief portion 2511, the maximum width of the groove 252 farther from the first surface 2511a is smaller than the minimum width of the groove 252 closer to the first surface 2511a.

[0096] In two adjacent grooves 252 along the thickness direction of the pressure relief section 2511, the maximum width of the groove 252 furthest from the first surface 2511a is smaller than the minimum width of the groove 252 closest to the first surface 2511a. In other words, the width of the multiple grooves 252 gradually decreases along the direction from the first surface 2511a to the second surface 2511b. The maximum width of the groove 252 furthest from the first surface 2511a and the minimum width of the groove 252 closest to the first surface 2511a are the dimensions of two adjacent grooves 252 in the same direction. The maximum width of the groove 252 furthest from the first surface 2511a does not restrict the width of the groove 252 furthest from the first surface 2511a in two adjacent grooves to be gradually changing. Even when the width of the groove 252 furthest from the first surface 2511a does not change along the thickness direction of the pressure relief section 2511, the width of the groove 252 furthest from the first surface 2511a can still be referred to as the maximum width. The minimum width of the groove 252 near the first surface 2511a does not restrict the width of the groove 252 near the first surface 2511a to be gradually changing between two adjacent grooves 252. When the width of the groove 252 near the first surface 2511a does not change along the thickness direction of the pressure relief part 2511, the width of the groove 252 near the first surface 2511a can also be referred to as the minimum width. In other words, when the width of the groove 252 does not change along the thickness direction of the pressure relief portion 2511, "among two adjacent grooves 252 in the thickness direction of the pressure relief portion 2511, the maximum width of the groove 252 away from the first surface 2511a is smaller than the minimum width of the groove 252 close to the first surface 2511a" can be understood as "among two adjacent grooves 252 in the thickness direction of the pressure relief portion 2511, the width of the groove 252 away from the first surface 2511a is smaller than the width of the groove 252 close to the first surface 2511a".

[0097] The pressure relief section 2511 may have two, three, four, or other grooves 252 arranged sequentially along its thickness direction. These grooves 252 can be formed using various methods, such as stamping or milling. For example, using stamping, multiple grooves 252 can be sequentially stamped along the direction from the first surface 2511a to the second surface 2511b on the pressure relief section 2511. For instance, if three grooves 252 are arranged sequentially along the thickness direction on the pressure relief section 2511, the first groove 252 can be stamped first on the first surface 2511a, then the second groove 252 can be stamped on the bottom surface of the first groove 252, and finally the third groove 252 can be stamped on the bottom surface of the second groove 252.

[0098] The first surface 2511a and the second surface 2511b of the pressure relief part 2511 are two surfaces of the pressure relief part 2511 that are opposite each other in the thickness direction. The distance between the first surface 2511a and the second surface 2511b is the thickness of the pressure relief part 2511.

[0099] The pressure relief body 251 can be a component mounted on the end cap 23, for example, the pressure relief body 251 can be an explosion-proof plate mounted on the end cap 23. The pressure relief body 251 can also be a housing 21 for accommodating the electrode assembly 22. A portion of the pressure relief body 251 can be the pressure relief section 2511, or the entire pressure relief body 251 can be the pressure relief section 2511. For example, the pressure relief body 251 can be an explosion-proof plate mounted on the end cap 23, or the entire pressure relief body 251 can be the pressure relief section 2511; or, if the pressure relief body 251 is a housing 21 for accommodating the electrode assembly 22, the pressure relief section 2511 can be a wall of the housing 21 or a portion of a wall.

[0100] In the pressure relief device 25, a plurality of grooves 252 are provided on the pressure relief part 2511. The grooves 252 are arranged sequentially on the pressure relief part 2511 from the first surface 2511a to the second surface 2511b. In two adjacent grooves 252 in the thickness direction of the pressure relief part 2511, the maximum width of the groove 252 away from the first surface 2511a is smaller than the minimum width of the groove 252 close to the first surface 2511a. The pressure relief device 25 with this structure adopts a multi-stage groove 252 structure, which can reduce the forming force on the pressure relief part 2511 when forming each stage of groove 252, reduce the risk of cracking of the pressure relief part 2511, and the pressure relief device 25 is less likely to fail due to cracks in the pressure relief part 2511 at the location where the grooves 252 are provided, thereby improving the long-term reliability of the pressure relief device 25.

[0101] When forming multiple grooves 252 on the pressure relief part 2511, the grooves 252 can be formed sequentially on the pressure relief part 2511 from the first surface 2511a to the second surface 2511b. The forming depth of each groove 252 is relatively shallow, which makes the forming force on the pressure relief part 2511 smaller. This can reduce the risk of cracking in the pressure relief part 2511 and improve the flatness of the first surface 2511a.

[0102] Furthermore, since the width of the multiple grooves 252 increases gradually along the direction from the second surface 2511b to the first surface 2511a, the pressure relief part 2511 can form a large crack after breaking at the location of the groove 252, which has a good pressure relief effect.

[0103] In some embodiments, please continue to refer to Figure 5 The plurality of grooves 252 include a first groove 2521 and a second groove 2522 extending in the same direction, wherein the first groove 2521 is disposed on the bottom surface of the second groove 2522.

[0104] The plurality of grooves 252 includes a first groove 2521 and a second groove 2522. That is, among the plurality of grooves 252, one groove 252 is the first groove 2521, and another groove 252 is the second groove 2522. Of course, there may be only two grooves 252 among the plurality of grooves 252, which are the first groove 2521 and the second groove 2522, respectively.

[0105] The first groove 2521 and the second groove 2522 extend in the same direction, meaning the length direction of the first groove 2521 is the same as the length direction of the second groove 2522. The bottom surface of the second groove 2522 refers to the surface of the groove wall closest to the second surface 2511b, that is, the surface connected to the side surface of the second groove 2522. The first groove 2521 is provided on the bottom surface of the second groove 2522. It can be understood that, in the thickness direction of the pressure relief part 2511, the first groove 2521 is closer to the second surface 2511b than the second groove 2522. The first groove 2521 is recessed from the bottom surface of the second groove 2522 towards the second surface 2511b. One or more first grooves 2521 can be provided on the bottom surface of the second groove 2522. For example, a first groove 2521 is provided on the bottom surface of the second groove 2522, that is, one first groove 2521 is provided for one second groove 2522. Of course, the first groove 2521 can be provided at the middle position of the bottom surface of the second groove 2522 in the width direction of the second groove 2522.

[0106] For example, such asFigure 5 As shown, when there are multiple notch grooves 252, but only two notch grooves 252 are included, the second notch groove 2522 is disposed on the first surface 2511a, that is, the second notch groove 2522 is recessed from the first surface 2511a towards the second surface 2511b. The distance between the two opposite sides of the second notch groove 2522 in its width direction gradually increases and decreases from the first surface 2511a to the second surface 2511b, that is, the width of the second notch groove 2522 gradually decreases along the direction from the first surface 2511a to the second surface 2511b. Of course, the two opposite sides of the second notch groove 2522 in its width direction can be inclined surfaces. Similarly, the distance between the two opposite sides of the first groove 2521 in its width direction gradually decreases from the first surface 2511a to the second surface 2511b, that is, the width of the first groove 2521 gradually decreases along the direction from the first surface 2511a to the second surface 2511b. Of course, the two opposite sides of the first groove 2521 in its width direction can also be inclined surfaces.

[0107] In this embodiment, since the extension direction of the first groove 2521 is consistent with the extension direction of the second groove 2522, and the first groove 2521 is disposed on the bottom surface of the second groove 2522, this structure facilitates the forming of the first groove 2521 and ensures the length of the first groove 2521. On the other hand, it can ensure that the maximum width of the first groove 2521 is less than the minimum width of the second groove 2522.

[0108] In some embodiments, please refer to Figure 6 and Figure 7 , Figure 6 A partial view of the pressure relief device 25 provided in some embodiments of this application. Figure 7 for Figure 6 The cross-sectional view of the pressure relief section 2511 shown shows that the plurality of grooves 252 also include a third groove 2523. The third groove 2523 is disposed on the first surface 2511a, and the second groove 2522 is disposed on the bottom surface of the third groove 2523.

[0109] The multiple grooves 252 also include a third groove 2523. It can be understood that the multiple grooves 252 may only include the first groove 2521, the second groove 2522 and the third groove 2523, or they may include other grooves 252 in addition to the first groove 2521, the second groove 2522 and the third groove 2523. For example, a groove 252 may be set on the bottom surface of the first groove 2521.

[0110] The third groove 2523 is disposed on the first surface 2511a, meaning the second groove 2522 is recessed from the first surface 2511a towards the second surface 2511b. The third groove 2523 is the groove 252 closest to the first surface 2511a. The bottom surface of the third groove 2523 refers to the surface of the groove wall of the third groove 2523 that is closest to the second surface 2511b, that is, the surface connected to the side surface of the groove of the third groove 2523. The second groove 2522 is disposed on the bottom surface of the third groove 2523. It can be understood that, in the thickness direction of the pressure relief part 2511, the second groove 2522 is closer to the second surface 2511b than the third groove 2523, and the second groove 2522 is recessed from the bottom surface of the third groove 2523 towards the second surface 2511b. A second groove 2522 can be provided on the bottom surface of the third groove 2523, or even multiple second grooves 2522.

[0111] In the above technical solution, the multiple scoring grooves 252 also include a third scoring groove 2523 disposed on the first surface 2511a, and the second scoring groove 2522 disposed on the bottom surface of the third scoring groove 2523. That is to say, the pressure relief part 2511 is provided with three levels of scoring grooves 252, which ensures that the forming force on the pressure relief part 2511 is not too large when forming each level of scoring groove 252, thereby reducing the risk of cracks in the pressure relief part 2511.

[0112] In some embodiments, please continue to refer to Figure 6 The bottom surface of the third groove 2523 is provided with multiple second grooves 2522.

[0113] The third groove 2523 can have various shapes, such as a circular groove, a rectangular groove, etc. For example, in... Figure 6 In the middle, the third groove 2523 is a rectangular groove.

[0114] The multiple second grooves 2522 provided on the bottom surface of the third groove 2523 can be arranged in various ways. For example, the multiple second grooves 2522 can be arranged in parallel, or, for example, ... Figure 6 As shown, multiple second grooves 2522 form an approximately "H" shaped structure.

[0115] In this embodiment, since the bottom surface of the third notch 2523 is provided with multiple second notches 2522, the pressure relief part 2511 can rupture at the position of each second notch 2522 to achieve pressure relief, resulting in a better pressure relief effect and an improved pressure relief rate. Furthermore, since one third notch 2523 corresponds to multiple second notches 2522, the molding process can be simplified and molding costs reduced.

[0116] In some embodiments, please refer to Figure 8, Figure 8 The Figure 6 positional relationship diagram of the first notch groove 2521, the second notch groove 2522, and the third notch groove 2523 shown. The multiple second notch grooves 2522 include a first groove segment 2522a, a second groove segment 2522b, and a third groove segment 2522c. The first groove segment 2522a and the second groove segment 2522b are arranged at intervals, and both the first groove segment 2522a and the second groove segment 2522b intersect with the third groove segment 2522c. The pressure relief portion 2511 includes an opening area 2511c jointly defined by the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c. The opening area 2511c is configured to open with the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c as boundaries.

[0117] The multiple second notch grooves 2522 include a first groove segment 2522a, a second groove segment 2522b, and a third groove segment 2522c. That is to say, among the multiple second notch grooves 2522, one second notch groove 2522 is the first groove segment 2522a, another second notch groove 2522 is the second groove segment 2522b, and yet another second notch groove 2522 is the third groove segment 2522c. Of course, it is possible that there are only three second notch grooves 2522 among the multiple second notch grooves 2522, and the three second notch grooves 2522 are respectively the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c.

[0118] The opening area 2511c is the area jointly defined by the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c of the pressure relief portion 2511. The opening area 2511c defined by the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c can be one or two. For example, when the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c form an approximate "匚" - shaped structure, the opening area 2511c is one; another example is that when the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c form an approximate "H" - shaped structure, the opening area 2511c is two.

[0119] The opening area 2511c is the area where the pressure relief portion 2511 relieves pressure. For the battery cell 20, when the internal pressure or temperature of the battery cell 20 reaches the threshold, the part of the pressure relief portion 2511 in the opening area 2511c will open with the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c as boundaries to achieve pressure relief.

[0120] Since multiple second grooves 2522 are provided on the bottom surface of the third groove 2523, the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c are all provided on the bottom surface of the third groove 2523. The opening area 2511c is located within the range of the third groove 2523. The third groove 2523 can provide clearance space for the part of the pressure relief part 2511 located in the opening area 2511c during the opening process bounded by the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c.

[0121] In this embodiment, since the first groove segment 2522a and the second groove segment 2522b are spaced apart, and both the second groove segment 2522b and the second groove segment 2522b intersect with the third groove segment 2522c, the first groove segment 2522a, the second groove segment 2522b and the third groove segment 2522c together define the opening area 2511c. This structure allows the pressure relief part 2511 located in the opening area 2511c to open and relieve pressure after the first groove segment 2522a, the second groove segment 2522b and the second groove segment 2522b break at their respective positions. This increases the pressure relief area of ​​the pressure relief part 2511 and improves the pressure relief rate of the pressure relief part 2511.

[0122] In some embodiments, please continue to refer to Figure 8 The plurality of second grooves 2522 also include a fourth groove segment 2522d, which is located between the first groove segment 2522a and the second groove segment 2522b in the extension direction of the third groove segment 2522c, and intersects with the third groove segment 2522c.

[0123] The plurality of second grooves 2522 includes a fourth groove segment 2522d. It is understood that the plurality of second grooves 2522 may include only the first groove segment 2522a, the second groove segment 2522b, the third groove segment 2522c, and the fourth groove segment 2522d, or it may include other groove segments in addition to the first groove segment 2522a, the second groove segment 2522b, the third groove segment 2522c, and the fourth groove segment 2522d. For example, the fourth groove segment 2522d may be parallel to the first groove segment 2522a and the second groove segment 2522b, and perpendicular to the third groove segment 2522c.

[0124] In this embodiment, the fourth groove segment 2522d, located between the first groove segment 2522a and the second groove segment 2522b, intersects with the third groove segment 2522c. The stress in the pressure relief part 2511 is more concentrated at the intersection of the third groove segment 2522c and the fourth groove segment 2522d, making it easier to break. This causes the pressure relief part 2511 to break along the third groove segment 2522c at the intersection of the third groove segment 2522c and the fourth groove segment 2522d during the pressure relief process, and then break along the first groove segment 2522a and the second groove segment 2522b after the third groove segment 2522c breaks, thereby achieving rapid pressure relief.

[0125] In some embodiments, the depth of the first groove segment 2522a is equal to the depth of the second groove segment 2522b, and the depth of the third groove segment 2522c is equal to the depth of the fourth groove segment 2522d. The depth of the first groove segment 2522a is less than the depth of the third groove segment 2522c, making it easier for the pressure relief section 2511 to rupture along the third groove segment 2522c at the intersection of the third groove segment 2522c and the fourth groove segment 2522d during the pressure relief process. In other embodiments, the depths of the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c are all less than the depth of the fourth groove segment 2522d. This also ensures that the pressure relief section is more likely to rupture along the third groove segment 2522c at the intersection of the third groove segment 2522c and the fourth groove segment 2522d during the pressure relief process.

[0126] In some embodiments, in the extending direction of the third slot segment 2522c, the distance from the intersection of the fourth slot segment 2522d and the third slot segment 2522c to the first slot segment 2522a is equal to the distance from the intersection of the fourth slot segment 2522d and the third slot segment 2522c to the second slot segment 2522b.

[0127] In the extending direction of the third slot segment 2522c, the distance from the intersection of the fourth slot segment 2522d and the third slot segment 2522c to the first slot segment 2522a is the length of the portion of the third slot segment 2522c between the fourth slot segment 2522d and the first slot segment 2522a. Similarly, in the extending direction of the third slot segment 2522c, the distance from the intersection of the fourth slot segment 2522d and the third slot segment 2522c to the second slot segment 2522b is the length of the portion of the third slot segment 2522c between the fourth slot segment 2522d and the second slot segment 2522b.

[0128] In this embodiment, since the distance from the intersection of the fourth groove segment 2522d and the third groove segment 2522c to the first groove segment 2522a is equal to the distance from the intersection of the fourth groove segment 2522d and the third groove segment 2522c to the second groove segment 2522b, the pressure relief part 2511 can rupture along the third groove segment 2522c at the intersection of the fourth groove segment 2522d and the third groove segment 2522c, and then rupture simultaneously along the first groove segment 2522a and the second groove segment 2522b.

[0129] In some embodiments, please continue to refer to Figure 8 The pressure relief body 251 is provided with a plurality of first grooves 2521, and the first grooves 2521 correspond one-to-one with the second grooves 2522. The plurality of first grooves 2521 include a fifth groove segment 2521a, a sixth groove segment 2521b and a seventh groove segment 2521c. The fifth groove segment 2521a is provided on the bottom surface of the first groove segment 2522a, the sixth groove segment 2521b is provided on the bottom surface of the second groove segment 2522b and the seventh groove segment 2521c is provided on the bottom surface of the third groove segment 2522c.

[0130] Among the multiple first grooves 2521, one first groove 2521 is the fifth groove segment 2521a, another first groove 2521 is the sixth groove segment 2521b, and yet another first groove 2521 is the seventh groove segment 2521c.

[0131] Among them, the extension direction of the fifth groove segment 2521a is consistent with the extension direction of the first groove segment 2522a, the extension direction of the sixth groove segment 2521b is consistent with the extension direction of the second groove segment 2522b, and the extension direction of the seventh groove segment 2521c is consistent with the extension direction of the third groove segment 2522c.

[0132] In some embodiments, the plurality of second grooves 2522 further include a fourth groove segment 2522d, which is located between the first groove segment 2522a and the second groove segment 2522b in the extending direction of the third groove segment 2522c, and intersects with the third groove segment 2522c; the plurality of first grooves 2521 further include an eighth groove segment 2521d, which is disposed on the bottom surface of the fourth groove segment 2522d.

[0133] The fourth groove segment 2522d is one of a plurality of second grooves 2522, and the eighth groove segment 2521d is one of a plurality of first grooves 2521. The eighth groove segment 2521d corresponds to the fourth groove segment 2522d, and the extension direction of the eighth groove segment 2521d is consistent with the extension direction of the fourth groove segment 2522d.

[0134] In some embodiments, please continue to refer to Figure 8The first slot segment 2522a, the second slot segment 2522b, and the third slot segment 2522c define two opening areas 2511c, which are located on both sides of the third slot segment 2522c.

[0135] The first slot segment 2522a, the second slot segment 2522b, and the third slot segment 2522c together define two opening areas 2511c, which can form an approximately "H"-shaped structure. The two opening areas 2511c are located on both sides of the third slot segment 2522c, so that the two opening areas 2511c are separated by the third slot segment 2522c. After the pressure relief part 2511 ruptures at the position of the third slot segment 2522c, the two opening areas 2511c will open in a split manner along the first slot segment 2522a and the second slot segment 2522b to achieve pressure relief.

[0136] It should be noted that regardless of whether the fourth groove segment 2522d is included in the multiple second grooves 2522, the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c can all define two open areas 2511c.

[0137] In this embodiment, since the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c define two opening areas 2511c, and the two opening areas 2511c are located on both sides of the third groove segment 2522c, during the pressure relief process, the pressure relief part 2511 in the two pressure relief areas can open in a split manner to relieve pressure, which can effectively improve the pressure relief rate of the pressure relief part 2511.

[0138] In some embodiments, please continue to refer to Figure 7 and Figure 8 The second surface 2511b is provided with a notch 253 that is at least partially located in the opening area 2511c. In the extending direction of the first groove segment 2522a, the notch 253 is at a distance from the third groove segment 2522c.

[0139] The second surface 2511b has a notch 253 that is at least partially located in the opening area 2511c. Understandably, the notch 253 is recessed from the second surface 2511b in a direction facing the first surface 2511a, and the notch 253 is at least partially located in the opening area 2511c. Of course, the notch 253 may be completely located within the opening area 2511c, or it may be partially located within the opening area 2511c.

[0140] The notch 253 can extend along the extension direction of the third groove segment 2522c, so that the notch 253 is parallel to the third groove segment 2522c.

[0141] In an embodiment where the first slot segment 2522a, the second slot segment 2522b, and the third slot segment 2522c jointly define an opening area 2511c, the first surface 2511a may be correspondingly provided with a notch 253. Combined with... Figure 7 and Figure 8 In the embodiment where the first groove segment 2522a, the second groove segment 2522b, and the third groove segment 2522c jointly define two opening areas 2511c, the first surface 2511a may be provided with two notch slots 253, and one notch slot 253 may be provided for one opening area 2511c.

[0142] In this embodiment, the notch 253 is at a distance from the third groove 2522c in the extending direction of the first groove segment 2522a, and at least a portion of the notch 253 is located within the opening area 2511c, so that during the pressure relief process, a portion of the pressure relief part 2511 located in the opening area 2511c can be rotated about the position of the pressure relief part 2511 located in the notch 253, making it easier to open and relieve pressure.

[0143] In some embodiments, the distance between the first surface 2511a and the second surface 2511b is H0, and the distance from the bottom surface of the groove 252 closest to the second surface 2511b to the second surface 2511b is H1. H0 and H1 satisfy the relationship: H1 / H0<0.2.

[0144] The distance between the first surface 2511a and the second surface 2511b is the thickness of the pressure relief portion 2511. The distance from the bottom surface of the groove 252 closest to the second surface 2511b to the second surface 2511b is the thickness of the portion between the bottom surface of the groove 252 closest to the second surface 2511b and the second surface 2511b. In embodiments where the multiple grooves 252 include only the first groove 2521, the second groove 2522, and the third groove 2523, the first groove 2521 is the groove 252 closest to the second surface 2511b.

[0145] In this embodiment, the ratio of the distance from the bottom surface of the groove 252 closest to the second surface 2511b to the distance from the first surface 2511a to the second surface 2511b is less than 0.2. This makes the thickness of the portion between the bottom surface of the groove 252 closest to the second surface 2511b and the second surface 2511b relatively small in the total thickness of the pressure relief portion 2511. This allows the portion between the bottom surface of the groove 252 closest to the second surface 2511b and the second surface 2511b to break normally, thereby achieving pressure relief.

[0146] In some embodiments, the distance from the bottom surface of the groove 252 closest to the second surface 2511b to the second surface 2511b is H1, where H1 satisfies the relationship H1<0.5mm.

[0147] In this embodiment, the distance from the bottom surface of the groove 252 closest to the second surface 2511b to the second surface 2511b is less than 0.5mm, which makes the thickness of the portion between the bottom surface of the groove 252 closest to the second surface 2511b and the second surface 2511b smaller, making it easier to break and release pressure.

[0148] In some embodiments, the depth of the groove 252 provided on the first surface 2511a is H2, where H2 satisfies the relationship H2<1mm.

[0149] The depth of the groove 252 provided on the first surface 2511a is the distance from the bottom surface of the groove 252 to the first surface 2511a. In embodiments where the multiple grooves 252 include a first groove 2521, a second groove 2522, and a third groove 2523, the third groove 2523 is the groove 252 provided on the first surface 2511a.

[0150] In this embodiment, the depth of the groove 252 provided on the first surface 2511a is less than 1 mm, which makes the depth of the outermost groove 252 of the pressure relief part 2511 smaller, thereby reducing the forming force on the pressure relief part 2511 in the groove 252 during the forming process and reducing the risk of cracking of the pressure relief part 2511.

[0151] In some embodiments, the depth of the groove 252 between the groove 252 closest to the second surface 2511b and the groove 252 disposed on the first surface 2511a is H3, where H3 satisfies the relationship H3<1.5mm.

[0152] In this embodiment, the plurality of grooves 252 includes at least three grooves 252. Taking the plurality of grooves 252 as an example, which only include a first groove 2521, a second groove 2522, and a third groove 2523, the groove 252 closest to the second surface 2511b is the first groove 2521, the groove 252 disposed on the first surface 2511a is the third groove 2523, and the groove 252 between the groove 252 closest to the second surface 2511b and the groove 252 disposed on the first surface 2511a is the second groove 2522.

[0153] In this embodiment, the depth of the groove 252 between the groove 252 closest to the second surface 2511b and the groove 252 provided on the first surface 2511a is less than 1.5mm. This results in a smaller depth of the grooves 252 on the pressure relief part 2511 other than the groove 252 closest to the second surface 2511b and the groove 252 provided on the first surface 2511a. This reduces the molding force on the pressure relief part 2511 during the molding process and reduces the risk of cracks in the pressure relief part 2511.

[0154] In some embodiments, please refer to Figure 9 , Figure 9 This is a schematic diagram of the structure of a pressure relief device 25 provided in some embodiments of this application. The pressure relief body 251 has an internal accommodating space. The pressure relief body 251 has a plurality of walls defining the accommodating space. The accommodating space is used to accommodate the electrode assembly 22. One of the plurality of walls has a pressure relief portion 2511.

[0155] One of the multiple walls has a pressure relief section 2511 formed therein. The pressure relief section 2511 can be a part of the wall or the entire wall. The first surface 2511a of the pressure relief section 2511 can be the outer surface or the inner surface of the wall. The outer surface of the wall is the surface of the wall that faces away from the electrode assembly 22, and the inner surface of the wall is the surface of the wall that faces the electrode assembly 22.

[0156] The pressure relief body 251 can be of various shapes, such as cuboid, cylinder, etc.

[0157] In this embodiment, the plurality of walls of the pressure relief body 251 define a receiving cavity for accommodating the electrode assembly 22, and one of the walls is formed with a pressure relief portion 2511, so that the pressure relief device 25 has both the function of accommodating the electrode assembly 22 and the function of pressure relief.

[0158] In some embodiments, please continue to refer to Figure 9 The pressure relief body 251 has multiple walls including a peripheral wall 2512 and a bottom wall 2513. The peripheral wall 2512 surrounds the edge of the bottom wall 2513. The peripheral wall 2512 and the bottom wall 2513 together define an accommodating space. The bottom wall 2513 has a pressure relief part 2511.

[0159] The peripheral wall 2512 surrounds the edge of the bottom wall 2513, which allows the pressure relief body 251 to form an opening at the opposite end of the bottom wall 2513, and the end cap 23 is used to cover the opening.

[0160] In embodiments where the pressure relief body 251 is cylindrical, the pressure relief body 251 may have two walls: a bottom wall 2513 and a peripheral wall 2512. For example... Figure 9As shown, in an embodiment where the pressure relief body 251 is a cuboid, the pressure relief body 251 may have five walls, one bottom wall 2513 and four side walls, with the four side walls connected end to end to form a peripheral wall 2512.

[0161] In some embodiments, the peripheral wall 2512 and the bottom wall 2513 are integrally formed structures.

[0162] The peripheral wall 2512 and the bottom wall 2513 are integrally formed, that is, the peripheral wall 2512 and the bottom wall 2513 are formed together in an integral manner.

[0163] In this embodiment, since the bottom wall 2513 has a pressure relief part 2511, and the peripheral wall 2512 and the bottom wall 2513 are integrally formed, the peripheral wall 2512 and the bottom wall 2513 with pressure relief function have good firmness. This integral design can simplify the molding process and reduce production costs.

[0164] In some embodiments, the first surface 2511a is the outer surface of the bottom wall 2513. That is, a plurality of grooves 252 on the pressure relief part 2511 are arranged sequentially from the outer surface of the bottom wall 2513 to the inner surface of the bottom wall 2513, which facilitates the processing of grooves 252 on the pressure relief body 251.

[0165] Secondly, embodiments of this application provide a battery cell 20, including the pressure relief device 25 provided in any of the above embodiments.

[0166] Thirdly, a battery 100 includes a housing 10 and a battery cell 20 provided in any of the above embodiments, wherein the housing 10 is used to house the battery cell 20.

[0167] Fourthly, an electrical device includes the battery 100 provided in any of the above embodiments.

[0168] The electrical equipment can be any of the devices that use battery 100 as described above.

[0169] Please refer to Figure 4 and Figure 5This application also provides a housing 21, which includes multiple walls that collectively define a receiving space for accommodating an electrode assembly 22. At least one wall has multiple grooves 252. The wall has opposing first surfaces 2511a and second surfaces 2511b in its thickness direction. The grooves 252 are arranged sequentially on the wall along the direction from the first surface 2511a to the second surface 2511b. In two adjacent grooves 252 in the thickness direction of the wall, the maximum width of the groove 252 farther from the first surface 2511a is smaller than the minimum width of the groove 252 closer to the first surface 2511a. This housing 21 integrates pressure relief and receiving functions. The multi-stage groove 252 structure can reduce the forming force on the housing 21 when forming each stage of groove 252, reduce the risk of cracking in the housing 21, and improve the long-term reliability of the pressure relief device 25.

[0170] This application provides a method for manufacturing a pressure relief device 25. Please refer to [link / reference]. Figure 10 , Figure 10 A flowchart illustrating a method for manufacturing a pressure relief device 25 provided in some embodiments of this application, the method comprising:

[0171] S100: Provide a pressure relief body 251, which includes a pressure relief portion 2511. The pressure relief portion 2511 has opposing first surfaces 2511a and second surfaces 2511b in its thickness direction.

[0172] S200: Multiple grooves 252 are sequentially machined on the pressure relief section 2511 along the direction from the first surface 2511a to the second surface 2511b; wherein, in two adjacent grooves 252 in the thickness direction, the maximum width of the groove 252 away from the first surface 2511a is smaller than the minimum width of the groove 252 close to the first surface 2511a.

[0173] In some embodiments, processing a plurality of grooves 252 sequentially on the pressure relief portion 2511 along the direction from the first surface 2511a to the second surface 2511b includes: stamping a plurality of grooves 252 sequentially on the pressure relief portion 2511 along the direction from the first surface 2511a to the second surface 2511b.

[0174] Multiple grooves 252 are sequentially formed on the pressure relief part 2511 from the first surface 2511a to the second surface 2511b by stamping. The forming process is simple and can reduce the stamping pressure on the pressure relief part 2511 when stamping each groove 252, thereby reducing the risk of cracking in the pressure relief part 2511.

[0175] It should be noted that the relevant structure of the pressure relief device 25 manufactured by the manufacturing method provided in the above embodiments can be found in the pressure relief device 25 provided in the foregoing embodiments, and will not be described again here.

[0176] Furthermore, this application embodiment provides a manufacturing apparatus 2000 for a pressure relief device 25, please refer to... Figure 11 , Figure 11 This is a schematic block diagram of a manufacturing apparatus 2000 for a pressure relief device 25 provided in some embodiments of this application. The manufacturing apparatus 2000 includes a first providing device 2100 and a processing device 2200. The first providing device 2100 is used to provide a pressure relief body 251, which includes a pressure relief portion 2511. The pressure relief portion 2511 has opposing first surfaces 2511a and second surfaces 2511b in its thickness direction. The processing device 2200 is used to sequentially process a plurality of grooves 252 on the pressure relief portion 2511 along the direction from the first surface 2511a to the second surface 2511b. Among two adjacent grooves 252 in the thickness direction, the maximum width of the groove 252 farther from the first surface 2511a is smaller than the minimum width of the groove 252 closer to the first surface 2511a.

[0177] It should be noted that the relevant structure of the pressure relief device 25 manufactured by the manufacturing equipment 2000 provided in the above embodiments can be found in the pressure relief device 25 provided in the foregoing embodiments, and will not be described again here.

[0178] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0179] 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, wherein, include: A pressure relief body includes a pressure relief portion, the pressure relief portion having opposing first and second surfaces in its thickness direction; Multiple grooves are arranged sequentially in the pressure relief section along the direction from the first surface to the second surface. In two adjacent grooves in the thickness direction, the maximum width of the groove farther from the first surface is smaller than the minimum width of the groove closer to the first surface. The multiple grooves include a first groove, a second groove, and a third groove with the same extension direction. The first groove is disposed on the bottom surface of the second groove, the third groove is disposed on the first surface, and the second groove is disposed on the bottom surface of the third groove. The bottom surface of the third groove is provided with multiple second grooves. The multiple second grooves include a first groove segment, a second groove segment, and a third groove segment. The first groove segment and the second groove segment are spaced apart and intersect with the third groove segment. The pressure relief section includes an opening area defined by the first groove segment, the second groove segment, and the third groove segment. The opening area is configured to open with the first groove segment, the second groove segment, and the third groove segment as the boundary. The second surface is provided with a notch located in the opening area. In the extension direction of the first groove segment, the notch is at a distance from the third groove segment. The notch is recessed from the second surface in the direction facing the first surface. The notch extends along the extension direction of the third groove segment and is parallel to the third groove segment.

2. The pressure relief device according to claim 1, wherein, The plurality of second grooves further includes a fourth groove segment, which is located between the first groove segment and the second groove segment in the extending direction of the third groove segment, and intersects with the third groove segment.

3. The pressure relief device according to claim 2, wherein, In the extending direction of the third groove segment, the distance from the intersection of the fourth groove segment and the third groove segment to the first groove segment is equal to the distance from the intersection of the fourth groove segment and the third groove segment to the second groove segment.

4. The pressure relief device according to claim 1, wherein, The pressure relief body is provided with a plurality of first grooves, and the first grooves correspond one-to-one with the second grooves; The plurality of first grooves include a fifth groove segment, a sixth groove segment, and a seventh groove segment. The fifth groove segment is disposed on the bottom surface of the first groove segment, the sixth groove segment is disposed on the bottom surface of the second groove segment, and the seventh groove segment is disposed on the bottom surface of the third groove segment.

5. The pressure relief device according to claim 4, wherein, The plurality of second grooves further includes a fourth groove segment, which is located between the first groove segment and the second groove segment in the extending direction of the third groove segment, and intersects with the third groove segment; The plurality of first grooves also include an eighth groove segment, which is disposed on the bottom surface of the fourth groove segment.

6. The pressure relief device according to claim 1, wherein, The first slot segment, the second slot segment, and the third slot segment define two open areas, which are located on both sides of the third slot segment.

7. The pressure relief device according to any one of claims 1-6, wherein, The distance between the first surface and the second surface is H0, and the distance from the bottom surface of the groove closest to the second surface to the second surface is H1. H0 and H1 satisfy the relationship: H1 / H0<0.

2.

8. The pressure relief device according to any one of claims 1-6, wherein, The distance from the bottom surface of the groove closest to the second surface to the second surface is H1, and H1 satisfies the relationship H1<0.5mm.

9. The pressure relief device according to any one of claims 1-6, wherein, The depth of the groove set on the first surface is H2, and H2 satisfies the relationship H2<1mm.

10. The pressure relief device according to any one of claims 1-6, wherein, The depth of the groove closest to the second surface and the groove disposed on the first surface is H3, and H3 satisfies the relationship H3<1.5mm.

11. The pressure relief device according to any one of claims 1-6, wherein, The pressure relief body has an internal accommodating space, and the pressure relief body has a plurality of walls defining the accommodating space. The accommodating space is used to accommodate an electrode assembly, and one of the plurality of walls forms the pressure relief portion.

12. The pressure relief device according to claim 11, wherein, The plurality of walls include 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 the receiving space, and the bottom wall forming the pressure relief portion.

13. The pressure relief device according to claim 12, wherein, The peripheral wall and the bottom wall are integrally formed.

14. The pressure relief device according to claim 12, wherein, The first surface is the outer surface of the bottom wall.

15. A battery cell comprising a pressure relief device according to any one of claims 1-14.

16. A battery comprising: The battery cell according to claim 15; as well as The housing is used to house the individual battery cells.

17. An electrical appliance comprising the battery according to claim 16.

18. A method for manufacturing a pressure relief device, the method comprising: A pressure relief body is provided, the pressure relief body including a pressure relief portion having opposing first and second surfaces in its thickness direction; Multiple grooves are sequentially machined on the pressure relief section along the direction from the first surface to the second surface; In two adjacent grooves along the thickness direction, the maximum width of the groove furthest from the first surface is less than the minimum width of the groove closest to the first surface. The plurality of grooves include a first groove, a second groove, and a third groove extending in the same direction. The first groove is disposed on the bottom surface of the second groove, the third groove is disposed on the first surface, and the second groove is disposed on the bottom surface of the third groove. The bottom surface of the third groove is provided with a plurality of second grooves. The plurality of second grooves include a first groove segment, a second groove segment, and a third groove segment. The first groove segment and the second groove segment are spaced apart and intersect with the third groove segment. The pressure relief section includes an opening area defined by the first groove segment, the second groove segment, and the third groove segment. The opening area is configured to open with the first groove segment, the second groove segment, and the third groove segment as boundaries. The second surface is provided with a notch located in the opening area. In the extension direction of the first groove segment, the notch is at a distance from the third groove segment. The notch is recessed from the second surface in the direction facing the first surface. The notch extends along the extension direction of the third groove segment and is parallel to the third groove segment.

19. The method for manufacturing the pressure relief device according to claim 18, wherein, The step of sequentially machining multiple grooves on the pressure relief portion along the direction from the first surface to the second surface includes: Multiple grooves are sequentially punched into the pressure relief section along the direction from the first surface to the second surface.

20. Manufacturing equipment for a pressure relief device, comprising: A first providing device is used to provide a pressure relief body, the pressure relief body including a pressure relief portion having opposing first and second surfaces in its thickness direction; as well as A processing device is used to sequentially process a plurality of grooves on the pressure relief part along the direction from the first surface to the second surface; In the thickness direction, among two adjacent grooves, the maximum width of the groove farther from the first surface is smaller than the minimum width of the groove closer to the first surface. The plurality of grooves include a first groove, a second groove, and a third groove with the same extension direction. The first groove is disposed on the bottom surface of the second groove, the third groove is disposed on the first surface, and the second groove is disposed on the bottom surface of the third groove. The bottom surface of the third groove is provided with a plurality of second grooves. The plurality of second grooves include a first groove segment, a second groove segment, and a third groove segment. The first groove segment and the second groove segment are spaced apart. The first groove segment and the second groove segment both intersect with the third groove segment. The pressure relief part includes an opening area defined by the first groove segment, the second groove segment, and the third groove segment. The opening area is configured to open with the first groove segment, the second groove segment, and the third groove segment as the boundary. The second surface is provided with a notch located in the opening area. In the extension direction of the first groove segment, the notch is at a distance from the third groove segment. The notch is recessed from the second surface in the direction facing the first surface. The notch extends along the extension direction of the third groove segment and is parallel to the third groove segment.

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